bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrothermal Formation of the Head-to-Head Coalesced Szaibelyite MgBO2(OH) Nanowires
Authors: Zhu Wancheng , Zhang Xueyi , Xiang Lan , Zhu Shenlin
Published: April 2009

The significant effect of the feeding mode on the morphology and size distribution of the hydrothermal synthesized MgBO2(OH) is investigated, which indicates that, slow dropping rate (0.5 drop s−1) and small droplet size (0.02 mL d−1) of the dropwise added NaOH solution are favorable for promoting the one-dimensional (1D) preferential growth and thus enlarging the aspect ratio of the 1D MgBO2(OH) nanostructures. The joint effect of the low concentration of the reactants and feeding mode on the hydrothermal product results in the head-to-head coalesced MgBO2(OH) nanowires with a length of 0.5–9.0 μm, a diameter of 20–70 nm, and an aspect ratio of 20–300 in absence of any capping reagents/surfactants or seeds.
Subcellular Localization of Thiol-Capped CdTe Quantum Dots in Living Cells
Authors: Zhang Yu , Mi Lan , Xiong Rongling , Wang Pei-Nan , Chen Ji-Yao , Yang Wuli , Wang Changchun , Peng Qian
Published: April 2009

Internalization and dynamic subcellular distribution of thiol-capped CdTe quantum dots (QDs) in living cells were studied by means of laser scanning confocal microscopy. These unfunctionalized QDs were well internalized into human hepatocellular carcinoma and rat basophilic leukemia cells in vitro. Co-localizations of QDs with lysosomes and Golgi complexes were observed, indicating that in addition to the well-known endosome-lysosome endocytosis pathway, the Golgi complex is also a main destination of the endocytosed QDs. The movement of the endocytosed QDs toward the Golgi complex in the perinuclear region of the cell was demonstrated.
Abies koreana Essential Oil Inhibits Drug‐Resistant Skin Pathogen Growth and LPS‐Induced Inflammatory Effects of Murine Macrophage
Authors: Yoon Weon‐Jong , Kim Sang‐Suk , Oh Tae‐Heon , Lee Nam Ho , Hyun Chang‐Gu
Published: April 2009

Since acne vulgaris is the combined result of a bacterial infection and the inflammatory response to that infection, we examined whether Abies koreana essential oil (AKE) possessed anti‐inflammatory and antibacterial activities against skin pathogens. In this study, AKE showed excellent antibacterial activities against drug‐susceptible and ‐resistant Propionibacterium acnes and Staphylococcus epidermidis, which are acne‐causing bacteria. In addition, AKE reduced the LPS‐induced secretion of tumor necrosis factor‐α (TNF‐α), interleukin‐1β (IL‐1β), IL‐6, NO and PGE2 in RAW 264.7 cells, indicating that it has anti‐inflammatory effects. Therefore, we suggest that AKE may be an attractive candidate for promoting skin health.
Selective Synthesis of Diacylglycerols of Conjugated Linoleic Acid
Authors: Hernández‐Martín Estela , Hill Charles G. , Otero Cristina
Published: April 2009

Quasi‐quantitative selective production of diacylglycerols (DAG) rich in polyunsaturated fatty acids (PUFA) was demonstrated using a Penicillium camembertii lipase. Under optimal initial conditions [60 °C, 10% (w/w) biocatalyst based on total reactants, 5:1 molar ratio of free conjugated linoleic acid (CLA) to hydroxyl groups in partial glycerides consisting of ca. 90% (w/w) monoacylglycerols (MAG) and ca. 10% (w/w) diacylglycerols (DAG)], reaction for only 4.5 h gave 98.62% DAG and 1.38% MAG. The DAG contained >95% unsaturated fatty acid residues. Predominant DAG were LnLn, LnL and LL, although LO and LP were also significant (Ln = linolenic; L = linoleic; O = oleic; P = palmitic). Effects of the acylating agent (free CLA), solvent, and temperature on undesirable side reactions were determined. Reaction selectivities were similar in n‐hexane and solvent‐free media. The re‐esterified products contained less than 7% saturated fatty acids and a higher ratio of unsaturated to saturated fatty acid residues (19.00) than the precursor soybean oil (5.22). The biocatalyst retained 55% of its initial activity after use in three consecutive reaction/extraction cycles.
Synergistic Effects of Antioxidants on the Oxidative Stability of Soybean Oil‐ and Poultry Fat‐Based Biodiesel
Authors: de Guzman Rhet , Tang Haiying , Salley Steven , Ng K. Y. Simon
Published: April 2009

Biodiesel is an alternative fuel composed of saturated and unsaturated methyl ester fatty acids that is very prone to oxidation attack. Exposure to air, heat, light, and metallic contaminants can lead to autoxidation, and the degradation of fuel properties such as kinematic viscosity and total acid number. This study examines the effectiveness of blends of primary antioxidants from combinations of butylated hydroxyanisole (BHA), propyl gallate (PG), pyrogallol (PY) and tert‐butyl hydroquinone (TBHQ) to increase oxidative stability. Results indicate that binary antioxidant formulations: TBHQ:BHA, TBHQ:PG and TBHQ:PY were most effective at 2:1, 1:1, 2:1 weight ratio, respectively in both distilled soybean oil‐ (DSBO) and distilled poultry fat‐ (DPF) based biodiesel. Antioxidant activity increased as the loadings were increased. The synergisms of the antioxidant pairs were different with different biodiesel types, suggesting a dependence on the fatty acid methyl ester (FAME) composition. The best synergistic effect was observed with the TBHQ:BHA blends while the best stabilization factors (SF) were achieved by using the TBHQ:PY blends. Quantification of antioxidant content in stored biodiesel with TBHQ:PY blend demonstrates that the main factor of synergy is the regeneration of PY by TBHQ.
Leisure activity patterns and their associations with overweight: A prospective study among adolescents
Authors: Lajunen Hanna‐Reetta , Keski‐Rahkonen Anna , Pulkkinen Lea , Rose Richard J. , Rissanen Aila , Kaprio Jaakko
Published: April 2009

We examined longitudinal associations between individual leisure activities (television viewing, video viewing, computer games, listening to music, board games, musical instrument playing, reading, arts, crafts, socializing, clubs or scouts, sports, outdoor activities) and being overweight using logistic regression and latent class analysis in a cohort of Finnish twins responding to self‐report questionnaires at 11–12 (N = 5184), 14, and 17 years. We also studied activity patterns (“Active and sociable”, “Active but less sociable”, “Passive but sociable”, “Passive and solitary”) thought to represent different lifestyles. Among boys, activity patterns did not predict becoming overweight, but sports and playing an instrument reduced the risk and arts and listening to music increased it. Among girls, few individual leisure activities predicted becoming overweight. However, girls in the “Passive and solitary” cluster carried the greatest risk of becoming overweight in late adolescence. Studying leisure activities related to overweight may help focus specific interventions on high risk groups.
General psychological acceptance and chronic pain: There is more to accept than the pain itself
Authors: McCracken Lance M. , Zhao‐O'Brien Jane
Published: April 2009

An increasing body of research demonstrates that acceptance of pain is significantly associated with the quality of daily functioning in people with chronic pain. The aim of the present study was to examine acceptance more broadly in relation to a wider range of undesirable experiences these people may encounter, such as other physical symptoms, experiences of emotional distress, or distressing thoughts. One hundred forty‐four, consecutive, adult patients attending interdisciplinary treatment for chronic pain participated in this study. They completed the Acceptance and Action Questionnaire‐II (AAQ‐II [Bond F, Hayes SC, Baer RA, Carpenter KM, Orcutt HK, Waltz T, Zettle RD. Preliminary psychometric properties of the Acceptance Action Questionnaire‐II: a revised measure of psychological flexibility and acceptance, submitted for publication]), measuring their general psychological acceptance. They also completed measures of emotional, physical, and psychosocial functioning, pain acceptance, and mindfulness. The AAQ‐II achieved satisfactory internal consistency, α = .89, and factor analysis revealed a unitary factor structure. Primary results showed that general psychological acceptance significantly correlated with depression, r = −.69, pain‐related anxiety, r = −.59, physical disability, r = −.42, and psychosocial disability, r = −.65, all p < .001. Hierarchical regression analyses showed that general psychological acceptance added a significant increment of explained variance to the prediction of patient functioning, independent of patient background characteristics, pain, acceptance of pain, and mindfulness. These results suggest that, when people with chronic pain are willing to have undesirable psychological experiences without attempting to control them, they may function better and suffer less. General acceptance may have a unique role to play in the disability and suffering of chronic pain beyond similar processes such as acceptance of pain or mindfulness.
A picture is worth a thousand words: Genomics to phenomics in the yeast Saccharomyces cerevisiae
Authors: Vizeacoumar Franco J. , Chong Yolanda , Boone Charles , Andrews Brenda J.
Published: April 2009

Large scale cell biological experiments are beginning to be applied as a systems‐level approach to decipher mechanisms that govern cellular function in health and disease. The use of automated microscopes combined with digital imaging, machine learning and other analytical tools has enabled high‐content screening (HCS) in a variety of experimental systems. Successful HCS screens demand careful attention to assay development, data acquisition methods and available genomic tools. In this minireview, we highlight developments in this field pertaining to yeast cell biology and discuss how we have combined HCS with methods for automated yeast genetics (synthetic genetic array (SGA) analysis) to enable systematic analysis of cell biological phenotypes in a variety of genetic backgrounds.
The posterosuperior quadrant of the tympanic membrane
Authors: Paço João , Branco Carla , Estibeiro Hugo , Oliveira e Carmo Diogo
Published: April 2009

Objective

To document the anatomic relationship of the posterosuperior segment of the tympanic membrane.

Study Design

Point‐prevalence study of postmortem material.

Subjects and Materials

One hundred seventy temporal bones from adults without history of otologic pathology were studied. The anatomic details of the tympanic membrane were observed, histology was documented on 30 sectioned bones, and, with the use of the scanning electron microscope, lamina propria was studied in 40 bones.

Results

We established that the posterosuperior quadrant was the largest, representing 28.7 percent of the total area of the eardrum. This feature implies that this quadrant is more likely than are the other quadrants to exhibit changes prompted by pressure challenges. We also verified that the posterosuperior part of tympanic sulcus, above the chorda tympanic nerve, lost its depth in an unexpected way in 60 percent of the cases. In association, we established that at this level there was a decrease in annulus caliber. In 25 percent of cases, by the absence of the circular fibers of lamina propria, the posterosuperior quadrant had only the radial fiber layer.

Conclusions

Anatomic and morphologic details in posterosuperior quadrant were newly described and may explain the greater incidence of retraction pockets and marginal perforations that provide origin for the cholesteatoma.
Modified uvulopalatopharyngoplasty for the treatment of obstructive sleep apnea‐hypopnea syndrome: Resection of the musculus uvulae
Authors: Shin Seung‐Heon , Ye Mi‐Kyung , Kim Chang‐Gyun
Published: April 2009

Objective

To assess the outcome of a modified uvulopalatopharynbgoplasty (UPPP) technique with preservation of the uvula mucosa and partial resection of the musculus uvula.

Study Design and Methods

A prospective randomized controlled trial. Sixteen male patients underwent a classic UPPP, and another 16 male patients underwent a modified UPPP. The parameters evaluated were the subjective symptom score, the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the Stanford Sleepiness Scale (SSS), and polysomnography results.

Results

Postoperative snoring, apnea, morning headache, daytime sleepiness, pharyngeal foreign body sensation, and global discomfort were not significantly different between the two groups. Among seven subjective measures of sleep quality from the PSQI, the subjective sleep quality was significantly improved in both groups. Postoperatively, the SSS was not significantly changed in both groups; however, the ESS was significantly improved in both groups. The polysomnographic findings showed a statistically significantly improvement in the apnea index and the apnea‐hypopnea index.

Conclusion

Although the modified group did not have more profound improvement in sleep quality and decreased postoperative pharyngeal discomfort, modified UPPP was an effective surgical method for the treatment of obstructive sleep apnea‐hypopnea syndrome.
Ethical challenges in geriatric care
Authors: Lucente Frank E.
Published: April 2009

The growth of the elderly population presents numerous challenges to the practicing otolaryngologist. This commentary reviews some of the issues that come up in dealing with geriatric patients, reiterates some classic ethical principles, and looks to some philosophers who have addressed relevant issues over the past centuries. It is based on a presentation “Ethical Challenges in Geriatric Otolaryngology,” delivered at the annual meeting of the American Society of Geriatric Otolaryngology on April 30, 2008.
Body mass index bias in defining obesity of diverse young adults: the Training Intervention and Genetics of Exercise Response (TIGER) Study
Authors: Jackson Andrew S. , Ellis Kenneth J. , McFarlin Brian K. , Sailors Mary H. , Bray Molly S.
Published: April 2009

The BMI cut-score used to define overweight and obesity was derived primarily using data from Caucasian men and women. The present study evaluated the racial/ethnic bias of BMI to estimate the adiposity of young men and women (aged 17–35 years) using dual-energy X-ray absorptiometry (DXA) determination of percentage body fat (DXA-BF%) as the referent standard. The samples were 806 women and 509 men who were tested from one to three times over 9 months providing 1300 observations for women and 820 observations for men. Linear mixed models (LMM) regression showed that with age and BMI controlled, DXA-BF% of African-American (AA) men and women, Asian-Indian men and women, Hispanic women and Asian women significantly differed from non-Hispanic white (NHW) men and women. For the same BMI of NHW women, the DXA-BF% of AA women was 1·76 % lower, but higher for Hispanic (1·65 %), Asian (2·65 %) and Asian-Indian (5·98 %) women. For the same BMI of NHW men, DXA-BF% of AA men was 4·59 % lower and 4·29 % higher for Asian-Indian men. Using the recommended BMI cut-scores to define overweight and obesity systematically overestimated overweight and obesity prevalence for AA men and women, and underestimated prevalence for Asian-Indian men and women, Asian women and Hispanic women. The present study extends the generalisability of research documenting the racial/ethnic bias of the universal overweight and obesity BMI cut-scores.
Potential impacts of wind farms on migratory birds crossing Spain
Authors: TELLERÍA JOSÉ LUIS
Published: April 2009

Over recent years, Spain has undergone a huge expansion in the number of wind farms, many of which extend across regions crossed by migratory birds that winter in the Iberian Peninsula and Africa. This paper explores the potential impact these structures have on the massive flow of birds along the western Pyrenean flyway. Ringing recoveries of migratory Wood PigeonsColumba palumbuswere used in the study to depict the movements of migratory birds and these were then compared to the distribution of wind farms. The main flow of pigeons (50% of ringing recoveries) was concentrated in a belt 50 km wide. Although the wind farms were mainly distributed outside this central belt, they intercepted an adjacent sector where a considerable number of ringed pigeons (30%) were recorded. This means that the two central bands (100 km wide) accounted for around 80% of the total number of Wood Pigeons crossing the region. These results suggest the need for a scrupulous evaluation of the potential impact of wind farms on migratory birds along this flyway, particularly the cumulative effect on populations crossing the region regularly. In view of the rapid expansion of wind farms in northern Spain, enforcement of the application of EU regulations on preventive measures to protect migratory species is urgently needed.
Assessment of exposure to methylmercury in pregnant Japanese women by FFQ
Authors: Yaginuma-Sakurai Kozue , Shimada Miyuki , Ohba Takashi , Nakai Kunihiko , Suzuki Keita , Kurokawa Naoyuki , Kameo Satomi , Satoh Hiroshi
Published: April 2009

Objective

To examine whether an FFQ can be used for assessing exposure to methylmercury (MeHg) by estimating MeHg intake from seafood consumption using the FFQ and confirming the accuracy of the estimated value.

Design

Seafood consumption of pregnant women was assessed using the FFQ. Total mercury (T-Hg) concentrations of maternal red blood cells (RBC) and hair were measured as exposure indices of MeHg.

Setting

A prospective birth cohort study, the Tohoku Study of Child Development (TSCD), which has been ongoing since 2001.

Subjects

The subjects were 609 pregnant Japanese women who were enrolled in the TSCD.

Results

MeHg intake was estimated from seafood consumption determined using the FFQ and the MeHg concentrations in each type of seafood. The accuracy of the estimated value was confirmed by comparison with T-Hg in RBC and hair. Estimated MeHg intake was 42·3 μg/week, and 43·0 % of that was from large predatory fish. Compared with the Japanese tolerable weekly intake, in total 12·5 % of the subjects exceeded it. T-Hg concentrations in RBC and hair were significantly correlated with estimated MeHg intake: r = 0·325 (P < 0·0001) for RBC and r = 0·305 (P < 0·0001) for hair.

Conclusions

Estimated MeHg intake based on the FFQ was significantly associated with T-Hg concentrations in RBC and hair. Although the estimated value involves uncertainties, the FFQ appears to be a useful tool for assessment of exposure to MeHg.
Effectiveness of recombinant human erythropoietin, vitamin D3and iron therapy on long-term survival of patients with end-stage renal disease receiving haemodialysis: analysis of 702 patients after 10-year follow-up
Authors: Chang Huan-Cheng , Chen Chien-Lung , Chiu Te-Li , Chen Shu-I , Yen Amy Ming-Fang , Chen Tony Hsiu-Hsi
Published: April 2009

Objective

Few studies have been conducted to investigate the influence of recombinant human erythropoietin (rhEPO) on the long-term prognosis of end-stage renal disease (ESRD).

Design

A retrospective cohort study.

Setting

The largest regional hospital renowned for haemodialysis in northern Taiwan.

Subjects

A total of 702 ESRD patients undergoing haemodialysis between 1993 and 2002 were evaluated.

Results

The rate of overall use of rhEPO, vitamin D3or Fe therapy was 62 %. The 10-year survival rate in patients with rhEPO supplementation was statistically more favourable than that in patients without rhEPO (hazard ratio (HR) = 0·38, 95 % CI 0·30, 0·47,P< 0·0001). Similar findings were noted for patients receiving vitamin D3(HR = 0·36, 95 % CI 0·21, 0·64,P= 0.0004) and Fe (HR = 0·45, 95 % CI 0·33, 0·61,P< 0·0001). After adjusting for age, education and aetiology, the administration of rhEPO resulted in statistically significant improvements in long-term survival rate either with (HR = 0·30, 95 % CI 0·22, 0·42) or without (HR = 0·48, 95 % CI 0·38, 0·61) combined use of Fe or vitamin D3.

Conclusions

We demonstrated a reduction in long-term mortality related to supplementation therapy with rhEPO, vitamin D3and Fe. The findings provide a justification for the administration of combined supplement therapy in patients undergoing haemodialysis.
Predictors of stunting and thinness in post-menarcheal adolescent girls in rural Bangladesh
Authors: Rah Jee H , Christian Parul , Shamim Abu Ahmed , Arju Ummeh T , Labrique Alain B , Rashid Mahbubur
Published: April 2009

Objective

To assess the nutritional status and risk factors of undernutrition in post-menarcheal girls in rural northern Bangladesh.

Design

Cross-sectional data on anthropometric measurements, dietary intake, work activity, morbidity and socio-economic status were collected from 12- to 19-year-old primigravidae (n 209) and never-pregnant adolescents (n 456) matched on age and time since menarche. Multiple regression analyses were conducted to determine predictors of stunting, thinness, upper-arm muscle (UAMZ) and fat area Z-scores (UAFZ) among the adolescent girls.

Results

A large proportion of adolescents (49 %) were stunted (height-for-age Z-score <−2) and underweight (40 %; weight-for-age Z-score <−2), but not thin (BMI-for-age <5th percentile; ∼10 %). The mean (sd) UAMZ and UAFZ of the adolescent girls was −0·3 (0·64) and −0·9 (0·40), respectively. Lean mass increased whereas fat mass declined with age. Both stunting and thinness were positively associated with age and time since menarche (P < 0·05). Young age (12–14 years) and literacy were protective against stunting among pregnant adolescents (OR = 0·29, 95 % CI 0·09, 0·88 and OR = 0·50, 95 % CI 0·26, 0·96, respectively). Having symptoms of diarrhoea or dysentery (OR = 7·40, 95 % CI 1·43, 38·29) predicted thinness and was associated with lower UAMZ and UAFZ among never-pregnant girls (both P < 0·05). Performing light-to-moderate activities was protective against thinness among never-pregnant girls (OR = 0·43, 95 % CI 0·22, 0·82), whereas pregnant adolescents who performed high levels of strenuous activities had greater UAMZ (P < 0·05).

Conclusion

Undernutrition was widespread among this post-menarcheal adolescent population. Younger and literate adolescents were less likely to be stunted, whereas thinness and body composition were associated with morbidity and work activity.
Disparities in fruit and vegetable supply: a potential health concern in the greater Québec City area
Authors: Pouliot Nathalie , Hamelin Anne-Marie
Published: April 2009

Objective

The present study explores the spatial distribution and in-store availability of fresh fruits and vegetables from a socio-environmental perspective in terms of the type of food store, level of deprivation and the setting (urban/rural) where the food outlets are located.

Design

Seven types of fresh fruit and vegetable stores (FVS) were identified then visited in six districts (urban setting) and seven communities (rural setting). The quantity and diversity of fresh fruits and vegetables (F&V) were also assessed.

Setting

Québec City, Canada.

Results

The FVS spatial distribution showed differences between the two settings, with accessibility to supermarkets being more limited in rural settings. The quantity and diversity of fresh F&V in-store availability were associated with the type of FVS, but not with setting or its level of deprivation. Greengrocers and supermarkets offered a greater quantity and diversity of fresh F&V than the other FVS.

Conclusions

The results suggest that inequalities in physical access to fresh F&V across the region could have an impact on public health planning considering that supermarkets, which are one of the excellent sources of F&V, are less prevalent in rural settings.
Factors influencing eating a varied diet in old age
Authors: Dean Moira , Raats Monique M , Grunert Klaus G , Lumbers Margaret ,   The Food in Later Life Team
Published: April 2009

Objective

To investigate the influences of resources and food-related goals on the variety of food choice among older people.

Design

A questionnaire-based survey in eight European countries: Poland, Portugal, United Kingdom, Germany, Sweden, Denmark, Italy and Spain.

Subjects

Participants (n3200) were above 65 years of age and living in their own homes. The samples were quota samples, eight groups of fifty in each country, based on gender, age and living circumstances, reflecting the diversity of each of the national populations based on education, income and urbanization of living environment.

Results

Hierarchical multiple regression analysis showed that income, health status, access to a car and living arrangement affected the level of dietary variety. The perceived level of different food-related resources impacted the consumption of a varied diet over and above actual resource levels. Food-related goals contributed to variety of food intake that was not accounted for by the amount of material resources possessed or the social and other resources perceived to be possessed.

Conclusions

Older people’s variety of food intake depended on material resources (e.g. monthly income, access to a car, living arrangement, physical and mental health). However, in addition to these variables, the way older people perceived other resources, such as their level of appetite, their food knowledge, their perception of the distance to the shops, access to high-quality products, having better kitchen facilities, access to good service providers and support from friends and neighbours, all contributed to how varied a diet they ate.
Rapid termination of the 2006 El Niño and its relation to the Indian Ocean
Authors: Yamanaka Goro , Yasuda Tamaki , Fujii Yosuke , Matsumoto Satoshi
Published: April 2009

We investigated the rapid termination of the 2006 El Niño using observed data and a coupled ocean‐atmosphere general circulation model (CGCM). Observed data showed development of an anomalous South Indian Ocean (SIO) anticyclone associated with the concurrent Indian Ocean Dipole during September–November 2006. At the end of 2006, the eastward retreat of the SIO anticyclone in response to the Indian Ocean warming generated an easterly anomaly over the western Pacific, and the resultant oceanic upwelling Kelvin wave terminated the El Niño. CGCM experiments indicated that the formation of the SIO anticyclone was influenced remotely by the Pacific Ocean SST anomalies, and that the easterly anomaly over the western Pacific at the end of 2006 was reinforced by the Indian Ocean SST anomalies. These results suggest that interactive feedback between the Indian and Pacific Oceans helped the rapid termination of the 2006 event.
Unusually elongated, bright airglow plume in the polar cap F region: Is it a tongue of ionization?
Authors: Hosokawa K. , Tsugawa T. , Shiokawa K. , Otsuka Y. , Ogawa T. , Hairston M. R.
Published: April 2009

We report an event of unusually elongated, bright airglow plume, which is considered as an optical manifestation of tongue of ionization (TOI) in the central polar cap. This optical structure was detected with an all‐sky airglow imager at Resolute Bay (74.73°N, 265.07°E) during a large magnetic storm on December 15, 2006. The absolute optical intensity of the plume was ≈1 kR, which is much brighter than that of non‐stormtime polar cap patches. Two‐dimensional imaging capability of the all‐sky imager demonstrates that some meso‐scale structures (≈250–600 km) were embedded within the plume. Simultaneous ion density and drift measurements with the DMSP spacecraft strongly suggest that the plume was extending from the dayside as a narrow stream of dense plasma and thus is an optical manifestation of polar cap TOI. The DMSP data also implies that the possible source of the plume is a narrow stream of storm enhanced density (SED) transported from lower latitudes. The DMSP auroral particle observation demonstrates that the polar cap extremely expanded equatorward during this interval. This extreme expansion allowed the anti‐sunward convection to capture plasmas within the SED and deliver them deep into the polar cap as a luminous airglow plume. This observation claims that the plasma transport from the dayside lower latitudes plays an important role in controlling the plasma environment in the polar cap ionosphere during magnetic storms.
Overexpression of the malate–aspartate NADH shuttle member Aralar1 in the clonal β-cell line BRIN-BD11 enhances amino-acid-stimulated insulin secretion and cell metabolism
Authors: Bender Katrin , Maechler Pierre , McClenaghan Neville H. , Flatt Peter R. , Newsholme Philip
Published: April 2009

In the present study, we have investigated the effects of the transduction with recombinant adenovirus AdCA-Aralar1 (aspartate–glutamate carrier 1) on the metabolism, function and secretory properties of the glucose- and amino-acid-responsive clonal insulin-secreting cell line BRIN-BD11. Aralar1 overexpression increased long-term (24 h) and acute (20 min) glucose- and amino-acid-stimulated insulin secretion, cellular glucose metabolism, L-alanine and L-glutamine consumption, cellular ATP and glutamate concentrations, and stimulated glutamate release. However, cellular triacylglycerol and glycogen contents were decreased as was lactate production. These findings indicate that increased malate–aspartate shuttle activity positively shifted β-cell metabolism, thereby increasing glycolysis capacity, stimulus–secretion coupling and, ultimately, enhancing insulin secretion. We conclude that Aralar1 is a key metabolic control site in insulin-secreting cells.
Fuzzy control design of a magnetically actuated optical image stabilizer with hysteresis compensation
Authors: Tu Tse-Yi , Chao Paul C.-P. , Chiu Chi-Wei , Wang Chun-Chieh , Huang Jeng-Shen
Published: April 2009

A fuzzy controller (FC) is designed for a magnetically actuated optical image stabilizer (OIS) in order to suppress the vibrations caused by hand shakings and hysteresis. To this end, the dynamic model of the OIS with consideration of hysteresis is first established, along with assuming the hand-shaking vibration as sinusoidal excitations. It is clearly shown that with capability of continuing parameter tuning, the FC is superior to the conventional PID for vibration suppression.
The intermixing induced perpendicular magnetic anisotropy in ultrathin Co/Pt multilayers
Authors: Su Chyun-H. , Lo Shen-Chuan , van Lierop J. , Lin K.-W. , Ouyang H.
Published: April 2009

It has been observed that a perpendicular interface contribution to the magnetic anisotropy can rotate the easy magnetization direction from within the film plane to perpendicular to the film plane when the Co thickness in Co/Pt multilayers is below a critical value that is in the range of (sub)nanometers. In this work, mixed CoPt phases mainly consisting of disordered fcc CoPt were found to be responsible for the perpendicular magnetic anisotropy (PMA) for the film deposition end-Hall voltage equal to 140 V. Estimates of mechanisms that could be responsible for the PMA such as “orange peel” coupling, exchange bias, and magnetostriction indicate that they are too weak. We believe that this PMA is driven by the heat of mixing and relatively higher interfacial energy since the Co layer thickness is about 1 nm.
Influence of diamagnetic Pb doping on the crystal structure and multiferroic properties of the BiFeO3 perovskite
Authors: Zhang Xingquan , Sui Yu , Wang Xianjie , Tang Jinke , Su Wenhui
Published: April 2009

Structural, magnetic, and electrical properties of Bi1−xPbxFeO3 (x=0, 0.1, 0.2, and 0.3) polycrystalline prepared by solid solution route were studied. The crystal structure data obtained from x-ray diffraction indicate that the solid solution Bi1−xPbxFeO3 successively transforms from rhombohedral to pseudocubic symmetry with an increase in the Pb concentration. The observed weak ferromagnetism and ferroelectricity at room temperature indicated the multiferroic nature of Pb-doped BiFeO3 compounds. The magnetoelectric coupling was estimated by the changes in the dielectric constant with an external magnetic field. It was found that the value of magnetodielectric effect have a maximum of 0.4% for Bi0.7Pb0.3FeO3 ceramic under a magnetic field of 12 kOe at room temperature.
Room-temperature ferromagneticlike behavior in Mn-implanted and postannealed InAs layers deposited by molecular beam epitaxy
Authors: González-Arrabal R. , González Y. , González L. , García-Hernández M. , Munnik F. , Martín-González M. S.
Published: April 2009

We report on the magnetic and structural properties of Ar- and Mn-implanted InAs epitaxial films grown on GaAs (100) by molecular beam epitaxy and the effect of rapid thermal annealing (RTA) for 30 s at 750 °C. Channeling particle induced x-ray emission (PIXE) experiments reveal that after Mn implantation almost all Mn atoms are substitutional in the In site of the InAs lattice, like in a diluted magnetic semiconductor. All of these samples show diamagnetic behavior. However, after RTA treatment the Mn–InAs films exhibit room-temperature magnetism. According to PIXE measurements the Mn atoms are no longer substitutional. When the same set of experiments was performed with Ar as implantation ion, all of the layers present diamagnetism without exception. This indicates that the appearance of room-temperature ferromagneticlike behavior in the Mn–InAs-RTA layer is not related to lattice disorder produced during implantation but to a Mn reaction produced after a short thermal treatment. X-ray diffraction patterns and Rutherford backscattering measurements evidence the segregation of an oxygen-deficient MnO2 phase (nominally MnO1.94) in the Mn–InAs-RTA epitaxial layers which might be the origin of the room-temperature ferromagneticlike response observed.
Parallel canonical Monte Carlo simulations through sequential updating of particles
Authors: O’Keeffe C. J. , Orkoulas G.
Published: April 2009

In canonical Monte Carlo simulations, sequential updating of particles is equivalent to random updating due to particle indistinguishability. In contrast, in grand canonical Monte Carlo simulations, sequential implementation of the particle transfer steps in a dense grid of distinct points in space improves both the serial and the parallel efficiency of the simulation. The main advantage of sequential updating in parallel canonical Monte Carlo simulations is the reduction in interprocessor communication, which is usually a slow process. In this work, we propose a parallelization method for canonical Monte Carlo simulations via domain decomposition techniques and sequential updating of particles. Each domain is further divided into a middle and two outer sections. Information exchange is required after the completion of the updating of the outer regions. During the updating of the middle section, communication does not occur unless a particle moves out of this section. Results on two- and three-dimensional Lennard-Jones fluids indicate a nearly perfect improvement in parallel efficiency for large systems.
Footprint structures due to resonant magnetic perturbations in DIII-D
Authors: Wingen A. , Evans T. E. , Spatschek K. H.
Published: April 2009

Numerical modeling of the typical footprint structures on the target plates of a divertor tokamak is presented. In the tokamak DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] toroidal mode number n=3 resonant magnetic perturbations are responsible for characteristic footprint stripes. The numerics can resolve substructures within each footprint stripe, which are related to the internal magnetic topology. It is shown that the footprint structures on the inner target plate can be predicted by the unstable manifolds of the separatrix and the q=4 resonant surface. By their intersection with the divertor target plate the unstable manifolds form the footprint boundary and substructures within. Based on the manifold analysis, the boundaries and interior structures of the footprints are explained. A direct connection of all magnetic resonances inside the stochastic plasma volume to the target plates is verified.
Clathrate guest atoms under pressure
Authors: Christensen M. , Johnsen S. , Juranyi F. , Iversen B. B.
Published: April 2009

Powder inelastic neutron scattering (INS) has been used to determine the guest atom “rattling” energy in thermoelectric clathrates Ba8YxGe46−x (Yx=Ni6,Cu6,Zn8,Ga16) under different applied conditions. Chemical pressure was exerted by the atomic substitution, and a physical pressure of 9 kbars was applied using a clamp cell. The volume reduction induced by the physical pressure increases the energy of the guest atom rattling mode, but the local chemical environment in the cage also appears to have a similar effect. The guest atom energies were investigated as function of temperature, and softening of the guest atom modes was observed upon cooling the sample. Ba8Ga16Ge30 with holes (p-type) and electrons (n-type) as charge carriers reveal similar temperature behavior, suggesting anharmonic potentials of similar shape for the Ba guest atom independent of the charge carrier type. For Sr8Ga16Ge30 a much stronger anharmonic potential was observed compared with Ba8Ga16Ge30. The guest atom energies for Ba8YxGe46−x (Yx=Ni6,Cu6,Zn8) extracted from powder INS were compared with Einstein energies obtained from atomic displacement parameters determined from multitemperature single crystal x-ray diffraction. Additionally, the Ba8YxGe46−x (Yx=Ni6,Cu6,Zn8) samples were characterized with respect to their thermoelectric properties.
Secondary flow behavior in a double bifurcation
Authors: Leong Fong Yew , Smith Kenneth A. , Wang Chi-Hwa
Published: April 2009

Secondary flows in the form of multivortex structures can occur in bifurcation models as the result of upstream influence. Results from numerical modeling of steady inspiratory flows indicate that, for the case of a symmetric planar double bifurcation, four counter-rotating vortices develop in each of the grand daughter branches. In this paper, experimental visualization and verification is provided by particle image velocimetry measurements on a modified single bifurcation model. A splitter plate was positioned in the mother tube so that secondary vorticity was introduced into the fluid core. The axial velocity profile before the bifurcation junction resembles the M-shaped velocity profile commonly observed in bifurcated tube flows. The result of this manipulation is the development of a physically observable four-vortex configuration in the cross sections of the daughter branches, thus demonstrating the strong influence of upstream secondary vorticity. Through numerical visualization of vortex lines, it is shown that secondary vorticity is amplified by the extension of vortex lines due to secondary flow within the daughter tube. Order-of-magnitude arguments have been applied to the vorticity transport equation; and key dimensionless parameters have been obtained, accounting for curvature effects. Results indicate that the secondary vorticity goes through a maximum with increasing downstream distance, as a result of the interplay between vortex stretching and viscous effects.
Photoreactivity of ZnO nanoparticles in visible light: Effect of surface states on electron transfer reaction
Authors: Baruah Sunandan , Sinha Sudarson Sekhar , Ghosh Barnali , Pal Samir Kumar , Raychaudhuri A. K. , Dutta Joydeep
Published: April 2009

Wide band gap metal oxide semiconductors such as zinc oxide (ZnO) show visible band photolysis that has been employed, among others, to degrade harmful organic contaminants into harmless mineral acids. Metal oxides show enhanced photocatalytic activity with the increase in electronic defects in the crystallites. By introducing defects into the crystal lattice of ZnO nanoparticles, we observe a redshift in the optical absorption shifting from the ultraviolet region to the visible region (400–700 nm), which is due to the creation of intermediate defect states that inhibit the electron hole recombination process. The defects were introduced by fast nucleation and growth of the nanoparticles by rapid heating using microwave irradiation and subsequent quenching during the precipitation reaction. To elucidate the nature of the photodegradation process, picosecond resolved time correlated single photon count (TCSPC) spectroscopy was carried out to record the electronic transitions resulting from the de-excitation of the electrons to their stable states. Photodegradation and TCSPC studies showed that defect engineered ZnO nanoparticles obtained through fast crystallization during growth lead to a faster initial degradation rate of methylene blue as compared to the conventionally synthesized nanoparticles.
Influence of phenolic hydroxyl groups on second-order optical nonlinearity at an example of 2,4- and 3,4-dihydroxyl hydrazone isomorphic crystals
Authors: Kwon O-Pil , Jazbinsek Mojca , Seo Jung-In , Choi Eun-Young , Yun Hoseop , Brunner Fabian D. J. , Lee Yoon Sup , Günter Peter
Published: April 2009

We investigate the crystal structure and physical properties of 2,4- and 3,4-dihydroxybenzaldehyde-4-nitrophenylhydrazone (DHNPH) isomer crystals to understand the relation between molecular ordering with noncovalent interactions based on phenolic OH groups. The microscopic and macroscopic optical nonlinearities of 2,4- and 3,4-DHNPH crystals are investigated experimentally and theoretically by using density functional theory calculations. Although the two isomer crystals possess a very similar molecular orientation based on a similar supramolecular synthon, 2,4-DHNPH exhibits a 1.7 times larger powder second harmonic generation efficiency than 3,4-DHNPH, which is attributed to their different intermolecular interactions involving phenolic OH groups. We show that the microscopic nonlinearity of the DHNPH molecules is particularly sensitive to variations in phenolic OH characteristics such as the orientation and intermolecular interactions.
A moment closure method for stochastic reaction networks
Authors: Lee Chang Hyeong , Kim Kyeong-Hun , Kim Pilwon
Published: April 2009

In this paper we present a moment closure method for stochastically modeled chemical or biochemical reaction networks. We derive a system of differential equations which describes the dynamics of means and all central moments from a chemical master equation. Truncating the system for the central moments at a certain moment term and using Taylor approximation, we obtain explicit representations of means and covariances and even higher central moments in recursive forms. This enables us to deal with the moments in successive differential equations and use conventional numerical methods for their approximations. Furthermore, we estimate the errors in the means and central moments generated by the approximation method. We also find the moments at equilibrium by solving truncated algebraic equations. We show in examples that numerical solutions based on the moment closure method are accurate and efficient by comparing the results to those of stochastic simulation algorithms.
Structural evolution of TiO2 nanocrystalline thin films by thermal annealing and swift heavy ion irradiation
Authors: Rath H. , Dash P. , Som T. , Satyam P. V. , Singh U. P. , Kulriya P. K. , Kanjilal D. , Avasthi D. K. , Mishra N. C.
Published: April 2009

The present study probes into the transition from anatase to rutile phase of TiO2 in 100 nm thick nanocrystalline thin films under thermal annealing and swift heavy ion (SHI) irradiation. The films were prepared using sol-gel and spin coating techniques on silicon (100) substrates. The as-deposited films are found to be amorphous by glancing angle x-ray diffraction and Raman spectroscopy. Though thermal annealing is known to cause transformation from anatase to rutile phase of TiO2 in a temperature interval of 700–900 °C, in nanoparticle thin films, we found that a sizable volume fraction of anatase still remains even after annealing at 1000 °C. Irradiations by 200 MeV Ag ions on the other hand suppressed the anatase phase and almost phase pure rutile TiO2 could be obtained at a fluence of 3×1012 ions cm−2. A mechanism based on the competing effect of grain growth and conversion of anatase to rutile at the grain boundary of the anatase on annealing and conversion of anatase to rutile in the grains of the anatase due to SHI induced thermal spike is proposed to explain the observed result.
Effects of gate insulator using high pressure annealing on the characteristics of solid phase crystallized polycrystalline silicon thin-film transistors
Authors: Kim Moojin , Jin GuangHai
Published: April 2009

The oxidizing ambient was built using high pressure H2O vapor at 550 °C. For the solid phase crystallization (SPC) polycrystalline silicon (poly-Si) that is annealed for 1 h at 2 MPa, the oxide thickness is about 150 Å. The oxide layer is approximately 90 Å above the original surface of the poly-Si and 60 Å below the original surface. The oxide layer is used as the first gate insulator layer of thin-film transistors (TFTs). The heating at 550 °C with 2 MPa H2O vapor increased the carrier mobility from 17.6 cm2/V s of the conventional SPC process to 30.4 cm2/V s, and it reduced the absolute value of the threshold voltage (Vth) from 4.13 to 3.62 V. The subthreshold swing also decreased from 0.72 to 0.60 V/decade. This improvement is attributed mainly to the reduction in defect density at the oxide/poly-Si interface and in the poly-Si film by the high pressure annealing (HPA) process. Since the realization of excellent performance at the oxide/poly-Si interface and in poly-Si depends on the defect density, the poly-Si having the thermal oxide formed by a combined process of SPC and HPA may be well suited for fabrication of poly-Si TFTs for flat panel displays such as active matrix organic light emitting diodes.
Characterization of electrochemically grafted molecular layers on silicon for electronic device applications
Authors: Scott Adina , Janes David B.
Published: April 2009

Recently, there has been considerable interest in developing organically functionalized silicon surfaces for a variety of applications including sensing and nanoelectronics. In this study, a series of as-deposited, para-substituted aryl-diazonium molecular layers covalently grafted to ⟨111⟩-orientation silicon are characterized using a variety of surface analysis techniques. Collectively, these measurements suggest that relatively ideal molecular layers can be achieved with a variety of headgroups. Submonolayer amounts of silicon oxide are detected on all modified surfaces and the extent of silicon oxidation depends on the molecular substituent. For electronic device applications, it is necessary to apply contacts to molecular layers while maintaining their structural and chemical integrity. To this end, in situ spectroscopies are used to infer the effects of metallization on such molecular layers. It is found that applying gold using a soft evaporation technique does not significantly perturb the molecular layer, whereas the application of copper using the same technique induces changes in the molecular vibrational spectra. Two complementary in situ spectroscopic methods are analyzed to more accurately determine the chemical properties of gold/molecule/silicon junctions. The physical mechanisms of the measurements and consequences for interpretation of the resulting spectra are discussed.
Closed-loop learning control of isomerization using shaped ultrafast laser pulses in the deep ultraviolet
Authors: Kotur Marija , Weinacht Thomas , Pearson Brett J. , Matsika Spiridoula
Published: April 2009

We demonstrate the use of shaped ultrafast laser pulses in the deep ultraviolet to control the ring opening isomerization of 1,3-cyclohexadiene to form 1,3,5-hexatriene. The experiments are performed with a gas phase sample and the isomerization yield is probed with dissociative ionization driven by a time-delayed, intense infrared laser pulse. Differences in the electronic structure of the ions for the two isomers, as shown by ab initio calculations, result in very different fragmentation products following strong-field ionization. We find that a shaped pulse yields a ∼37% increase in the isomerization over an unshaped laser pulse.