bluuebunny/crossref_metadata_2025_split huggingface dataset:
GaN/Al0.5Ga0.5N quantum dots and quantum dashes
Authors: Huault Thomas , Brault Julien , Natali Franck , Damilano Benjamin , Lefebvre Denis , Tauk Rabih , Leroux Mathieu , Massies Jean 
Published: January 2009

AbstractGaN/Al0.5Ga0.5N nanostructures grown on c ‐plane sapphire by molecular beam epitaxy using ammonia as N source have been studied. Depending on the ammonia pressure during the two dimensional – three dimensional transition of the GaN layer, the shape of the islands is strongly modified: elongated or isotropic islands are observed, leading to the formation of quantum dashes or quantum dots, respectively. This shape transition is seen as a consequence of a change in surface energy. The change of morphology of the GaN layer is clearly evidenced by photoluminescence measurements, and a large redshift in the emission peak is observed for quantum dashes as compared to quantum dots. An electric field ∼3 MV/cm is estimated from the measurements at an excitation power ∼20 mW/cm2. Weak photoluminescence quenching between low and room temperature for both QDs and QDashes structures is observed, indicating a strong confinement of carriers into the nanostructures. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin control by ultra short laser pulses in a Mn doped quantum dot
Authors: Reiter Doris E. , Axt Vollrath Martin , Kuhn Tilmann 
Published: January 2009

AbstractOptically induced spin flip processes in quantum dots doped with a single Mn atom are discussed. On the femtosecond time scale the exciton can be controlled by ultra short laser pulses. Via the exchange interaction the Mn spin can flip on a picosecond time scale by transferring its angular momentum to the exciton. For a heavy hole system this flipping process can be described in terms of exchange‐induced Rabi oscillations between the bright and dark exciton state accompanied by a flip of the Mn spin. Because of the energy splitting between bright and dark excitons the Rabi oscillations are off‐resonant and a series of laser pulses is required to achieve a complete flip. When a light hole exciton is resonantly excited in addition to the heavy hole exciton we show that a flip of the Mn spin by two can be achieved by a series of light pulses while the exciton system returns to its initial state. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low resistance ohmic contacts annealed at 600 °C on a InAlN/GaN heterostructure with SiCl4‐reactive ion etching surface treatment
Authors: Pozzovivo G. , Kuzmik J. , Giesen C. , Heuken M. , Liday J. , Strasser G. , Pogany D. 
Published: January 2009

AbstractIn this paper, the effect of the surface treatments on the performance of Ti/Al/Ni/Au ohmic contacts to InAlN/GaN has been investigated by electrical characterization and by normalized Auger electron spectroscopy (AES). Contact resistance and specific contacts resistivity as low as 0.7 Ωmm and 1.1×10–7 Ωcm2, respectively, have been achieved by pre‐treatment using SiCl4 plasma followed by rapid thermal annealing at at 600 °C. This is compared with the case where no plasma pre‐treatment was performed. Contacts without pretreatment and annealed at at 600 °C were still rectifying and at the optimized annealing temperature of 800 °C reach 1.7 Ωmm contact resistance. Moreover, AES investigations showed that the presence of Carbon impurities on the InAlN surface has been significantly reduced after SiCl4 RIE pre‐treatment. That may account for improved ohmic contacts resistance and lowered optimised temperature of annealing for pre‐treated contacts. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Light extraction enhancement of sapphire‐free InGaN LEDs using single‐ and double‐side surface roughening techniques
Authors: Wuu Dong‐Sing , Hsieh Chuang‐Yu , Laio Tzu‐Wei , Zheng Xinhe , Horng Ray‐Hua 
Published: January 2009

AbstractWe compare the performance of three types of GaN‐based light‐emitting diodes (LEDs) epitaxially grown on patterned sapphire substrates (PSSs). For the devices with a single roughened p‐GaN surface, the light output power of the original LEDs with the PSS and Ag reflector (Sample A) is lower than that of thin‐film LEDs transferred onto Si carriers via glue bonding (Sample B). While the thin GaN LEDs with double‐side roughening (both p‐GaN and micropillar undoped‐GaN surfaces) and glue/Ag omnidirectional reflector (Sample C) shows much higher light output power than that of Sample B. As compared with the Sample A, the Sample C shows a performance enhancement of 50.3% in light output power and 46.3% in power efficiency at 350 mA. These results reflect that the contribution of the micropillar undoped‐GaN texturing for the light extraction is dominant. The employment of Si carrier decreases the junction temperature of the Sample C, a 46.6 °C lower than that of the conventional LEDs on PSS. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Realization of high‐crystalline‐quality and thick GaInN films
Authors: Senda Ryota , Matsubara Tetsuya , Iida Daisuke , Iwaya Motoaki , Kamiyama Satoshi , Amano Hiroshi , Akasaki Isamu 
Published: January 2009

AbstractWe report on the growth of a completely relaxed, high‐ crystalline‐quality, and thick GaInN layer on a grooved m‐plane GaN template using sidewall epitaxial lateral overgrowth (SELO) technology. We grew GaInN‐based multiple quantum wells (MQWs) on this GaInN layer, and the PL intensity was compared with that for the same GaInN/GaN MQWs on m‐plane GaN grown by SELO. The PL peak intensity obtained from the GaInN/GaN MQW on the high‐crystalline‐quality thick GaInN on grooved GaN was approximately 1.7 times higher than that on the SELO m‐plane GaN template. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study on antifibrotic effects of curcumin in rat hepatic stellate cells
Authors: Lin Yun‐Lian , Lin Chia‐Yu , Chi Chin‐Wen , Huang Yi‐Tsau 
Published: January 2009

AbstractSuppression of activation or fibrogenesis and induction of apoptosis, in hepatic stellate cells (HSCs) have been proposed as therapeutic strategies against liver fibrosis. Curcumin, an active compound isolated from yellow curry pigment of turmeric (Curcuma longa Linn), has been demonstrated to be an effective anti‐inflammatory and antioxidant compound. In this study, we investigated the in vitro antifibrogenic effects of curcumin on HSCs at the concentration range of (1–40 µM). A cell line of rat HSCs (HSC‐T6) was stimulated with transforming growth factor‐β1 (TGF‐β1). The inhibitory effects of curcumin (1.25∼10 µM) on fibrosis‐related markers including α‐smooth muscle actin (α‐SMA) and collagen were assessed. In addition, the induction effects of curcumin (20∼40 µM) on apoptosis in HSC‐T6 cells were also assessed by Hoechst and propidium iodide stains. Curcumin (1.25∼10 µM) concentration‐dependently suppressed TGF‐β1‐induced α‐SMA expression and collagen deposition in HSC‐T6 cells, without cytotoxicity. Whereas, higher concentrations of curcumin (20∼40 µM) induced cell apoptosis and cytochrome c release in HSC‐T6 cells. Our results suggest that curcumin exerted antifibrotic effects, possibly through two different mechanisms depending on its concentrations. At lower concentrations (1.25∼10 µM), curcumin exerted antifibrogenic effects, whereas at higher concentrations (20∼40 µM), curcumin exerted induction of apoptosis in HSCs. Copyright © 2009 John Wiley & Sons, Ltd.
Modulations in the planetary wave field induced by upward‐propagating Rossby wave packets prior to stratospheric sudden warming events: A case‐study
Authors: Nishii Kazuaki , Nakamura Hisashi , Miyasaka Takafumi 
Published: January 2009

AbstractA diagnostic framework is introduced in which anomalous zonally averaged Rossby wave‐activity injection into the stratosphere is decomposed into a contribution solely from zonally confined upward‐propagating Rossby wave packets and another from interaction of the wave packets with the climatological planetary waves. To pinpoint the tropospheric sources of the wave packets, a particular form of wave‐activity flux is evaluated for the associated circulation anomalies. The framework is applied to reanalysis data for the period prior to a stratospheric sudden warming (SSW) event in January 2006, which was associated with two successive events of above‐normal wave‐activity injection from the troposphere. In the earlier event, a pair of wave packets that emanated from tropospheric anomalies over the North Pacific and over Europe enhanced the upward wave‐activity injection, which was augmented further by their interaction with the climatological planetary wave. In contrast, in the later period a wave packet that emanated from an anticyclonic anomaly over the North Atlantic is found to be the primary contributor to the enhanced planetary wave‐activity injection, while its interaction with the climatological planetary wave contributed negatively. The predominant importance of the sole contribution from a single wave packet is also found in a major SSW event observed over Antarctica in September 2002. These results indicate that the diagnostic framework presented in this study is a useful tool for understanding the interaction between anomalies associated with zonally confined wave packets and climatological‐mean planetary waves in the study of stratosphere‐‐troposphere dynamical coupling. Copyright © 2009 Royal Meteorological Society
Data Mining: A Gateway to Better Data Gathering
Authors: Doganaksoy Necip , Hahn Gerald J. 
Published: January 2009

AbstractIn many situations, data mining results—due to the deficiencies in the available data—in less than definitive conclusions. This is especially the case when one is seeking cause‐and‐effect relationships. The major value of data mining in such cases is as part of an iterative process that leads to improved data gathering, or even controlled experimentation, to permit improved data analysis in the future. This is illustrated by an example that assesses the impact of taking action to reduce future fraudulent activities by Internet users who had been found engaged in such activities. Copyright © 2009 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 1: 000‐000, 2009
Periodic Large‐Area Metallic Split‐Ring Resonator Metamaterial Fabrication Based on Shadow Nanosphere Lithography
Authors: Gwinner Michael Christian , Koroknay Elisabeth , Fu Liwei , Patoka Piotr , Kandulski Witold , Giersig Michael , Giessen Harald 
Published: January 2009

AbstractA fast and cheap, large‐area (>1 cm2), high‐coverage fabrication technique for periodic metallic split‐ring resonator metamaterials is presented, which allows control of inner‐ and outer‐ring diameters, gap angles, as well as thickness and periodicity. This method, based on shadow nanosphere lithography, uses tilted‐angle‐rotation thermal evaporation onto Langmuir–Blodgett‐type monolayers of close‐packed polystyrene nanospheres. Excellent agreement of the process parameters with a simplified model is demonstrated. Pronounced, tunable optical metamaterial resonances in the range of 100 THz are consistent with simulations.
DNA Methylation-Associated Repression of Cancer-Germline Genes in Human Embryonic and Adult Stem Cells
Authors: Loriot Axelle , Reister Sven , Parvizi Gregory K. , Lysy Philippe A. , De Smet Charles 
Published: January 2009

Abstract
Cancer-germline (CG) genes are a particular group of germline-specific genes that rely primarily on DNA methylation for repression in somatic tissues. In a wide variety of tumors, the promoter of these genes is demethylated, and their transcription is activated. The mechanism underlying this tumor-specific activation is still unclear. It was recently suggested that CG gene expression may be a hallmark of stem cells, and that expression of these genes in several tumors may reflect the expansion of constitutively expressing cancer stem cells. To clarify this issue, we carefully evaluated the expression of several CG genes in human stem cells of embryonic and adult origin. We found no or very weak expression of CG genes in these cells. Consistently, the promoter of CG genes was highly methylated in these cells. We conclude that CG genes do not qualify as “stemness” genes, and propose that their activation in cancers results from a tumor-specific activation process.
Disclosure of potential conflicts of interest is found at the end of this article.
Fatty Acid Profile Analysis of Membrane Phospholipids of Isolated Soybean Lipid Bodies
Authors: Simpson T. D. 
Published: January 2009

AbstractPhospholipids in isolated soybean lipid bodies at 30‡C underwent degradation by acyl ester and phosphodiester hydrolysis and by phosphatidyl transfer. Under conditions that minimized oxidation, preferential loss of phosphatidylethanolamine and polyunsaturated fatty acids occurred, but acyl ester compositions of all phospholipids reflected enrichment of saturated and/or monounsaturated acids. Such fatty acid changes in phosphatidylinositol, which was degraded less than phosphatidylcholine or phosphatidylethanolamine, and in phosphatidic acid, which accumulated, also suggest that transesterification occurred extensively in lipid bodies. The specific temporal changes in phospholipid and acyl chain composition suggest that several enzymes remained active in isolated lipid bodies.
Fluorination of Hydroxyesters with N,N‐Diethyl‐1,1,2,3,3,3‐Hexafluoro Propaneamine
Authors: Watanabe S. , Fujita T. , Sakamoto M. , Arai T. , Kttazume T. 
Published: January 2009

AbstractThe reactions of N,N‐diethyl‐1,1,2,3,3,3‐hexafluoro propaneamine (PPDA) with Β‐hydroxyl esters gave their corresponding fluorides. For example, methyl (S)‐(+)‐3‐fluorobutyrate was obtained from the reaction of methyl (R)‐(‐)‐3‐hydroxybutyrate with PPDA. The reaction ofa‐hydroxy esters with PPDA gave a mixture of their corresponding fluorides and 2,3,3,3‐tetrafluoropropionate esters. However, γ‐ and δ‐hydroxyesters did not give their fluorinated compounds. Hydrolysis of those racemic monofluoroesters with Lipase MY gave optical active monofluorocarboxylic acids and esters.
High performance size exclusion chromatography of monomer, dimer and trimer mixtures
Authors: Christopoulou C. N. , Perkins E. G. 
Published: January 2009

AbstractA high performance size exclusion Chromatographic method was developed for the separation of monomer, dimer and trimer fatty acids in thermally oxidized or used fats and oils. The system was composed of two styrene/divinylbenzene copolymer columns with toluene as the mobile phase and refractometry as the mode of detection. The internal standardization method was used for quantitation with monostearin as the internal standard. Quantitation of monomer, dimer and trimer content in various samples correlated well with results obtained by GLC analysis and gravimetically by size exclusion chromatography.
An in vitro method for evaluation of the irritancy of antonio surfactants
Authors: Anavkar A. S. , Natraj C. V. 
Published: January 2009

AbstractExtraction of Coomassie Brilliant Blue R250 dye from gelatin by anionic surfactants was found to be proportional to the concentration, duration of extraction, and the nature of the surfactant. Under a given set of conditions, the decreasing order of dye extraction was SLS > LAS > sodium laurate > AOS ≅ SLES. This order agrees well with the decreasing order of irritancy of these surfactants. For a homologous series such as sodium salts of carboxylic acids, there was a sharp maximum in dye extraction for laurate. This coincides with the reported order of irritancy for soaps of fatty acids. Substitution of gelatin by agar or Coomassie Brilliant Blue by eosin abolished this specificity. Thus, the measurement of extraction of Coomassie Brilliant Blue R250 from gelatin is a reproducible and simple method for estimating the irritancy of anionic surfactants.
Stage III Thick (>4.0 mm) Lower Extremity Melanoma: Is Timing of Lymph Node Involvement a Prognostic Factor?
Authors: Herman Krzysztof , Wysocki Wojciech M. , Skotnicki Piotr , Tabor Jacek , Łuczyńska Elebieta , Komorowski Andrzej L. 
Published: January 2009

AbstractPurposeThe prognosis for stage III melanoma patients is mixed, and there is need for new prognostic factors to be incorporated into a revision of melanoma TNM staging. We analyzed the possible role of the timing of lymph node involvement as an important prognostic factor.MethodsAmong 249 melanoma patients who underwent ilioinguinal lymphadenectomy, a group of 185 patients with a thick (>4mm) melanoma and full clinical data available was analyzed. The mean depth of invasion was 5.85 mm; the tumor was ulcerated in 67 cases (36.2%); and Clark V was diagnosed in 82 patients (44.3%). The median interval between primary excision and the time of lymphadenectomy was 11.1 months.ResultsRecurrent disease was reported in 150 of 185 patients. The first sites of recurrence were the skin in 15.7%, lymph nodes in 13.5%, and distant metastases in 28.7%; the remaining 43 patients (23.2%) had multifocal recurrences. In all, 35 patients (18.9%) were disease‐free. Skip metastases (positive iliac and negative inguinal lymph nodes) were found in 26 patients (14%). Multivariate Cox analysis showed that only the time between the first surgery and lymphadenectomy and the number of involved nodes were significant predictors of survival. Relative risk of death was 5.2 times higher for patients who had simultaneously undergone lymphadenectomy (compared to lymph dissection performed >1 year after primary excision) and about 2.7 times higher for those with more regionally advanced disease (pN3 vs. pN1).ConclusionsThe long disease‐free interval before the development of lymph node metastases and before node dissection is a favorable prognostic factor independent of other well known parameters.
Effect of Temperature, Modified Atmosphere and Ethylene During Olive Storage on Quality and Bitterness Level of the Oil
Authors: Yousfi Khaled , Cayuela José A. , García José M. 
Published: January 2009

AbstractMill olives (Olea europaea L. cv. ‘Lechín’), harvested at the green mature stage of ripening, were stored for 72 h under six different storage conditions: in air, in a closed container, and in a closed container with 30 ppm ethylene either at 20 or at 40 °C. The use of 40 °C as the fruit storage temperature reduced oil bitterness, regardless of the atmosphere applied; however, it also induced a significant reduction in stability and pigment content of the oil extracted. At 20 °C, mill olives stored under air supplemented with 30 ppm ethylene engendered oils with middle bitterness intensity, whereas the oils obtained from fruit stored similarly, but without ethylene, or in an open container exhibited a strong intensity of this sensory attribute. Fruit respiration in the closed containers caused a CO2 accumulation and an O2 decrease in the storage atmosphere. This CO2 concentration was increased by the previous ethylene addition, but O2 presence did not suffer an additional reduction. The use of modified atmospheres in fruit storage induced off‐flavor development in the oils extracted, producing a significant reduction in the overall grading of their sensory quality.
Femoral shaft fractures treated with stainless steel flexible nails in children aged between 5 and 12 years at the HUSVP: A two-year follow-up
Authors: Ríos Alejandro Uribe , Arango Diego Fernando Sanín , Molina Carlos Oliver Valderrama , de Jesús Toro Posada Álvaro 
Published: January 2009

Purpose The purpose of this study is to show our experience with stainless steel flexible nails in the treatment of femoral shaft fractures in children aged between 5 and 12 years and to observe if the type of material used for nails affects the results. Materials A prospective, descriptive study of a series of cases was performed to evaluate patients treated at the Hospital Universitario San Vicente de Paúl (HUSVP) who had been followed up for at least 24 months. Results The study group was composed of 48 patients, with an average age of 8.6 years. According to the AO classification, the most common type of fracture was 32A3.2 (61%). The average follow-up period was 43 months. The alterations observed were six cases of clinical length discrepancy, two cases of overgrowing, four cases of shortening, and two malunions in valgus. These alterations had no repercussion in the children's function. The follow-up is the main strength of this study, as it demonstrated that, 2 years after surgery. Conclusion The results with stainless steel nails are as good as those with titanium nails with a shorter follow-up as reported in the literature. Given the high costs of osteosynthesis material in our country, the results of this study provide a less expensive alternative. Level of evidence IV, case series.
Evaluation of women presenting with postcoital bleeding by cytology and colposcopy
Authors: Tehranian Afsaneh , Rezaii Negar , Mohit Mitra , Eslami Bita , Arab Malihe , Asgari Zahra 
Published: January 2009

AbstractObjectiveTo evaluate women with postcoital bleeding (PCB) by clinical examination, cytology, colposcopy, and histopathology.MethodsA cross‐sectional study of 123 women with PCB, who were referred to the Colposcopy Clinic of Arash Hospital, Tehran, over a 2‐year period.ResultsClinical examinations revealed cervical polyps in 18 women and ectropion in 14. Cervical cytology identified 13 patients with atypical squamous cells of undetermined significance, 2 with atypical glandular cells, 4 with low‐grade squamous intraepithelial lesions, and 3 with high‐grade squamous intraepithelial lesions. Colposcopy indicated invasive cancer in 1 patient. Transitional zones appeared normal in 39.8% of the cohort, were atypical grade 1 in 33.3%, and atypical grade 2 in 4.9%. Fourteen abnormalities were detected at histology, including 1 squamous cell carcinoma, 1 low‐grade glandular neoplasm, 9 cervical intraepithelial neoplasia (CIN) grade 1, 2 CIN grade 2, and 1 CIN grade 3. The sensitivity and specificity of cytology were 50% and 86.5%, respectively. A total of 21.4% of abnormal pathologies were missed using colposcopy, which had a sensitivity of 79%.ConclusionBecause of its higher sensitivity, colposcopy can be recommended for the investigation of persistent PCB, even in the presence of normal cytology.
Scandinavian Realism
Authors: Hart H. L. A. 
Published: January 2009

English and Scandinavian legal theory have long shared many points of view. Among these are the belief that law is something man-made and made for men; hostility or indifference to doctrines of natural law at least in the scholastic form; and a general disbelief in the capacity of philosophical systems to throw light either on what law is or ought to be. Yet notwithstanding these similarities the principal Scandinavian tradition in legal theory has a different tone from its English counterpart. Though professedly sceptical in aim and empirical in method, it is much more like a kind of philosophy. The work of the founder of this tradition, Axel Hägerstrom, had for its motto Censeo metaphysicam esse delendam and is a sustained effort to show that notions commonly accepted as essential parts of the structure of law such as rights, duties, transfers of rights and validity, are in part composed of superstitious beliefs, “myths,” “fictions,” “magic” or rank confusion. This tradition, continued in the work of his disciples Lundstedt, Olivecrona and Alf Ross, has made contact with both American “rule-scepticism” and contemporary linguistic philosophy. Its latest most sophisticated product is Ross's recently published book On Law and Justice.1This is in many ways an interesting book, and at points a brilliant one, though by no means free from the fiery dogmatism of Scandinavian “realist” jurisprudence. Ross is less tortuous and obscure than Hägerstrom, less naïve and professorial than Lundstedt; and richer in illuminating examples and concrete detail, if less urbane, than Oliveerona.