bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of chemotherapy on disseminated low‐grade glioma in children and adolescents: Report from the HIT‐LGG 1996 trial
Authors: von Hornstein Stephan , Kortmann Rolf‐D. , Pietsch Torsten , Emser Angela , Warmuth‐Metz Monika , Soerensen Niels , Straeter Ronald , Graf Norbert , Thieme Barbara , Gnekow Astrid K.
Published: February 2011

Background

We describe demographic data of disseminated childhood low‐grade glioma (DLGG) prospectively recruited in the HIT‐LGG 1996 study and evaluate the impact of primary chemotherapy (CT) on the outcome of these tumors, which have previously only been described in small and retrospective series.

Patients and Methods

The multicenter study HIT‐LGG 1996 accrued 1181 children and adolescents with low‐grade glioma. 61 patients (5.2%) had tumor dissemination, with 2.8% being present at diagnosis. Frequencies of dissemination for different subgroups were calculated. Efficiency of first‐line CT with vincristine/carboplatin was defined in 24 children with dissemination prior to first‐line non‐surgical‐treatment.

Results

Incidence of dissemination was high among infants (16%) with hypothalamic‐chiasmatic‐glioma (HCG) and diencephalic syndrome. A relevant percentage of HCG showed isolated spinal dissemination. CT achieved objective and overall response rates of 25% and 79% of the primary tumor and a similar response of disseminated lesions. Clinical stabilization or improvement could be achieved in the majority of patients during treatment. However, 20 of 24 patients experienced further progression and 5‐year PFS was 6%. Dissemination prior to CT was a negative prognostic factor for PFS within the study (P = 0.005).

Overall‐survival of primary DLGG was inferior compared to LGG without dissemination at diagnosis (P < 0.001).

Conclusion

Complete MRI scan should be a standard diagnostic procedure in young children with hypothalamic‐chiasmatic tumors especially if presenting with diencephalic syndrome. Dissemination in childhood LGG relates to impaired PFS. CT delays progression for responders. Multicenter studies have to evaluate the efficacy of extended treatment strategies in DLGG to improve outcome. Pediatr Blood Cancer 2011;56:1046–1054. © 2011 Wiley‐Liss, Inc.
FondaKIDS: A prospective pharmacokinetic and safety study of fondaparinux in children between 1 and 18 years of age
Authors: Young Guy , Yee Donald L. , O'Brien Sarah H. , Khanna Rachna , Barbour April , Nugent Diane J.
Published: February 2011

Background

The incidence of thromboembolic disease is increasing in children. New anticoagulants have been licensed in adults and need to be studied in children. This report describes the first prospective study of fondaparinux in children.

Procedure

The purpose of the study was to determine the dosing, pharmacokinetics, and safety of fondaparinux in children with deep vein thrombosis (DVT) or heparin‐induced thrombocytopenia (HIT). Hospitalized children between 1 and 18 years of age with DVT or HIT received fondaparinux 0.1 mg/kg once daily. Fondaparinux‐based anti‐factor Xa levels were assessed at 2, 4, 12, and 24 hr following the first dose, and peak levels were measured twice weekly thereafter. Detailed pharmacokinetic analyses were performed.

Results

Twenty four subjects in 3 age cohorts were enrolled and completed the study. Pharmacokinetic modeling demonstrated that a once‐daily dose of fondaparinux at 0.1 mg/kg resulted in similar concentrations known to be efficacious in adults. Safety was demonstrated with only two bleeding events: one which may have pre‐dated study drug administration and one which led only to temporary discontinuation of study drug.

Conclusion

Dosing of fondaparinux at 0.1 mg/kg once daily in children resulted in PK profiles comparable to those in adults receiving standard dosing. Fondaparinux can be considered an attractive alternative to LMWH given its once‐daily dosing, acceptable safety data, and other favorable properties. Pediatr Blood Cancer 2011; 57: 1049–1054. © 2011 Wiley‐Liss, Inc.
Health related quality of life in adolescent and young adult survivors of lower extremity bone tumors
Authors: Barrera Maru , Teall Tanya , Barr Ronald , Silva Mariana , Greenberg Mark
Published: February 2011

Background

Dramatic increases in survival rates have led to increased interest regarding the health related quality of life (HRQOL) of adolescent and young adult survivors of bone tumors. This study investigated HRQOL and physical disability in adolescent and young adult survivors of lower extremity bone tumors as a function of type of surgical intervention, gender, and age at assessment.

Procedure

Twenty‐eight participants (age range 18–32 years) completed three generic and one disease‐specific measures of HRQOL and a measure of physical disability. For analysis, surgical intervention was grouped into limb sparing surgeries (LS; allograft fusion and endoprosthesis) and ablative surgeries (AMP; amputation or Van Nes rotationplasty). Age at study was grouped into ≤25 years of age and ≥26 years of age. The MOS‐SF‐36, HUI2, HUI3, and EORTC‐QLQ‐C30 were used to measure HRQOL and the TESS was used to assess physical disability.

Results

Survivors reported HRQOL equivalent to the general population, with the exception of physical functioning. LS reported poorer HRQOL than AMP participants for emotional functioning and fatigue. Males reported better HRQOL compared with females for overall HRQOL, general health, physical functioning, and social functioning. Finally, younger participants generally reported better HRQOL than older participants for overall HRQOL and physical functioning.

Conclusions

This study identifies LS surgical intervention, female gender and older age as risk factors for reduced HRQOL in adolescent and young adult survivors of lower extremity bone tumors. This study also provides information about what instrument may be most useful in identifying these specific difficulties and subgroups. Pediatr Blood Cancer 2012; 58: 265–273. © 2011 Wiley Periodicals, Inc.
Religious coping and the use of prayer in children with sickle cell disease
Authors: Cotton Sian , Grossoehme Daniel , McGrady Meghan E.
Published: February 2011

Background

While adolescents and adults with sickle cell disease (SCD) have reported using religion to cope with SCD, there is no data examining religious coping in young children with SCD. The purpose of this qualitative study was to: (1) describe the types of religious coping used by children with SCD; (2) describe the content and frequency of prayer used in relation to SCD; and (3) examine how children viewed God/Higher Power in relation to their SCD.

Procedure

Children with SCD participated in a semi‐structured interview and an art drawing exercise focused on the use of general coping and religious coping. Interviews were coded, organized, and analyzed using a template organizational style of interpretation and NVivo 8.0 qualitative software.

Results

Of the 19 participants, the average age was 8.05 years (SD ±1.81); 11 were female (58%); all (100%) were African‐American and 9 (47%) were Protestant. Children used religion to gain control, make meaning, and find comfort. Most children reported praying to get well, to keep from getting sick, and to get out of the hospital. Children described a functional God who made them take their medicine or took them to the hospital and an emotional God who made them happy and comforted them when they were sad or scared.

Conclusions

These children with SCD reported using religion to help cope with the illness. Providers should be aware of the importance of religion to many of these children and integrate religion, as appropriate, into discussions about coping with SCD. Pediatr Blood Cancer 2012; 58: 244–249. © 2011 Wiley Periodicals, Inc.
Neuropathic pain during treatment for childhood acute lymphoblastic leukemia
Authors: Anghelescu Doralina L. , Faughnan Lane G. , Jeha Sima , Relling Mary V. , Hinds Pamela S. , Sandlund John T. , Cheng Cheng , Pei Deqing , Hankins Gisele , Pauley Jennifer L. , Pui Ching‐Hon
Published: February 2011

Background

Improved cure rates for childhood acute lymphoblastic leukemia (ALL) over the past 2 decades have allowed greater attention to patients' quality of life. Neuropathic pain (NP) is an unpleasant side effect of chemotherapeutic agents for leukemia, especially vincristine.

Procedure

We retrospectively reviewed the records of 498 patients treated on a single protocol for ALL to investigate the risk factors, the incidence, and the use of therapeutic and prophylactic gabapentin treatment for NP.

Results

White non‐Hispanic race was the only patient variable predictive of NP. One hundred and seventy‐four of 498 patients (34.9%) experienced 207 episodes of NP; 16% (28 of 174) patients experienced at least one recurrence of pain after the initial episode. No statistical significance was found in the relation between the severity (grade) of the NP episode and the cumulative dose of vincristine (P = 0.45) or the vincristine dose that immediately preceded the diagnosis (1.5 mg/m2 versus 2.0 mg/m2 [correction made here after initial online publication], P = 0.59). Of 180 episodes with treatment data, 62.2% (112) and 37.8% (68) were treated with gabapentin or opioids, respectively. The selection of treatment with gabapentin or opioids was not influenced by the pain intensity score at the time of diagnosis of NP (P = 0.91). The mean gabapentin dose used for 112 episodes was 15.5 mg/kg/day (SD 7.9). We found no evidence that gabapentin prevented recurrence of NP.

Conclusions

Our results highlight the need for prospective randomized studies to elucidate the value of gabapentin regimen for prevention or treatment of vincristine‐related pain during treatment of childhood leukemia. Pediatr Blood Cancer 2011; 57: 1147–1153. © 2011 Wiley Periodicals, Inc.
Use of sentinel node biopsy for staging parameningeal rhabdomyosarcoma
Authors: Weiss Brian D. , Dasgupta Roshni , Gelfand Michael J. , Laor Tal , Yin Hong , Breneman John C. , Lavigne Ruth , Elluru Ravindhra G. , Wagner Lars M.
Published: February 2011

Identification of nodal involvement is important for treatment planning in patients with rhabdomyosarcoma, and is facilitated by sentinel node biopsy. Although it is employed primarily for extremity tumors, we report using sentinel node biopsy in a patient with parameningeal rhabdomyosarcoma arising in the ethmoid sinus. Lymphoscintigraphy with single photon emission computed tomography following injection of tracer at the tumor site helped identify contralateral cervical node involvement not previously recognized by physical exam, cross sectional imaging, or other functional imaging. This case demonstrates how information from sentinel node identification and biopsy can change therapy recommendations in patients with parameningeal rhabdomyosarcoma. Pediatr Blood Cancer 2011; 57: 520–523. © 2011 Wiley‐Liss, Inc.
Siblings presenting with progressive congenital aleukemic leukemia cutis
Authors: Agrawal Anurag K. , Guo Hua , Golden Carla
Published: February 2011

Congenital leukemia is infrequent, occurring in <1% of pediatric leukemia patients, and mainly of myeloid lineage. Twenty‐five to 30% of congenital leukemia cases present with cutaneous leukemic infiltrates. Rarely, infants will have aleukemic leukemia cutis, presenting with leukemic skin lesions but without systemic symptoms or bone marrow involvement. Few cases of congenital aleukemic leukemia cutis have been reported in the literature. The course of disease is variable as cases of spontaneous resolution have been described. Here we present the first report of siblings with progressive congenital aleukemic leukemia cutis, both treated successfully with myeloid leukemia chemotherapy. Pediatr Blood Cancer 2011; 57: 338–340. © 2011 Wiley‐Liss, Inc.
Laser desorption ionisation–time of flight mass spectrometry of the tolyporphins, bioactive metabolites from the cyanobacterium Tolypothrix nodosa
Authors: Prinsep Michèle R. , Puddick Jonathan
Published: February 2011

Introduction – The tolyporphins are metabolites isolated from the cyanobacterium Tolypothrix nodosa, comprising a porphyrin‐like macrocycle with C‐glycoside, hydroxide or acetate substituents. Previous studies of porphyrins by MALDI/LDI‐TOF MS indicate that strong radical cations and anions are usually observed in the parent spectra with little fragmentation of the macrocycle. The spectra of the tolyporphins were obtained and trends in the series utilised to partially characterise two new analogues.

Objective – To examine tolyporphins by LDI‐TOF MS and utilise trends observed to partially characterise two new analogues.

Methodology – The tolyporphins were analysed by LDI‐TOF MS in positive and negative ion mode and by a post source decay method (LIFT) in positive ion mode. Tolyporphin A was also analysed by MALDI‐TOF MS for comparison. Results were analysed and used to obtain structural information on two new analogues.

Results and Discussion – The resulting spectra generally contained intense radical cations or anions, with little fragmentation of the macrocyclic core or the C‐glycosides observed. These results are consistent with previous studies of porphyrins. Major fragment ions observed in LIFT spectra yielded key structural information. An inseparable mixture of two tolyporphins was also examined. Analysis of the LIFT spectrum of the parent ion resulted in the postulation of structures of these two new analogues.

Conclusions – Tolyporphins yield LDI‐TOF mass spectra somewhat analogous to those of porphyrins; furthermore, the substituents fragment in a characteristic manner permitting partial characterisation of the new analogues tolyporphins L and M by comparison of their LDI‐TOF mass spectra with those of the known analogues. Copyright © 2011 John Wiley & Sons, Ltd.
Selective ethylene‐permeable zeolite composite double‐layered film for novel modified atmosphere packaging
Authors: Monprasit P. , Ritvirulh C. , Sooknoi T. , Rukchonlatee S. , Fuongfuchat A. , Sirikittikul D.
Published: February 2011

The composite double‐layered films, for the packaging application of postharvest fruits and vegetables, were prepared by laminating low‐density polyethylene (LDPE) and poly[styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene] (SEBS) modified with zeolite ZSM‐5. The film was characterized by scanning electron microscope and differential scanning calorimeter and tested for permeation of ethylene (C2H4), oxygen (O2), carbon dioxide (CO2), and water vapor. It was found that the C2H4 permeability of the films was improved because of an enhanced adsorption of C2H4 by the incorporated zeolite (0–10 wt%). The preconcentrated layer (zeolite/SEBS) leads to a higher C2H4 concentration gradient across the film. Moreover, the high dispersion of zeolite increased the C2H4 permeation. When compared with O2 and CO2, the composite films were more selective to C2H4. However, the C2H4 permeation decreased in the presence of O2 because of a competitive adsorption. In addition, the films possessed appreciate tensile properties for packaging application. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Preparation and properties of bitumen modified with the maleic anhydride grafted styrene‐butadiene‐styrene triblock copolymer
Authors: Cong Peiliang , Chen Shuanfa , Chen Huaxin
Published: February 2011

A procedure to improve the properties of styrene‐butadiene‐styrene (SBS) copolymer modified bitumen by grafting of maleic anhydride (MAH) onto SBS in the presence of benzoyl peroxide (BPO) as initiator was proposed. The effects of the grafting degree (GD) on the properties of modified bitumen were investigated. FTIR spectroscopy was employed to verify the grafting of MAH onto SBS. The GD of MAH onto SBS was determined by a back titration procedure. To assess the effects of the GD of grafted SBS on properties of modified bitumen, the softening point, penetration, ductility, elastic recovery, penetration index, viscosity, storage stability, and dynamic shear properties were tested. Experimental results indicated that the SBS grafted with maleic anhydride (SBS‐g‐MAH) copolymer was successfully synthesized by solvothermal method, and different GD of the SBS‐g‐MAH was obtained by control the MAH concentration. The GD of the MAH onto SBS has great effect on the rheological properties of the modified bitumen, and the high temperature performance and storage stability of modified bitumen were improved with the GD of the MAH onto SBS increasing. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Newly designed polyacrylamide/dextran gels for electrophoresis protein separation: synthesis and characterization
Authors: Ainseba‐Chirani Naziha , Dembahri Zahra , Tokarski Caroline , Rolando Christian , Benmouna Mustapha
Published: February 2011

Newly designed gels for electrophoresis protein separation were synthesized from acrylamide, N,N′‐methylenebis (acrylamide) and dextran mixtures. Radical polymerization was initiated by ammonium persulfate and N,N,N′,N′‐tetramethylethylenediamine. The time dependence of absorbance during polymerization was monitored using UV‐visible spectroscopy. The exothermic polymerization process exhibited a sharp rise of temperature reminiscent of the Trommsdorff effect. The swelling kinetics of the synthesized gels was examined in deionized water and buffer solutions. One of the challenges was to find an alternative to commercial products, sold as mixtures with no detailed chemical contents, commonly used in sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS‐PAGE) for protein separation. For this reason, a systematic comparison was made of the properties of one of the most commonly used commercial gels, Duracryl™ from Genomics Solution Inc., and those of the synthesized polyacrylamide/dextran gels. Copyright © 2011 Society of Chemical Industry
Basic hydrolysis of quinolinyl N,N‐dimethylcarbamates: a two‐step mechanism
Authors: Silva Daniel , Norberto Fátima , Santos Susana , Iley Jim
Published: February 2011

The reactivity of 6‐quinolinyl and 8‐quinolinyl N,N‐dimethylcarbamates was examined in several aqueous basic media. A quadratic dependence was observed for the constant rates upon hydroxide concentration for both compounds, which is a typical behaviour of a mechanism involving a base‐catalysed deprotonation of the tetrahedral intermediate with the formation of a dianion at high concentrations of hydroxide ion, while at lower concentrations a specific‐base catalysed addition–elimination mechanism seems to be predominant. The reactivity of 8‐quinolinyl N,N‐dimethylcarbamate was also studied in several amine buffers, showing specific base catalysis. The reactivity of 6‐quinolinyl N,N‐dimethylcarbamate was studied in H2O and in D2O and the solvent isotope effect supports the proposal of a mechanism involving a specific‐base hydrolysis. All results confirm the existence of a mechanism with a rate determining step involving the substrate anion and a second mole of hydroxide ion. This mechanism was so far unknown for carbamate reactivity, being only known to occur with amides. Copyright © 2011 John Wiley & Sons, Ltd.
β‐Elimination of an aziridine to an allylic amine: a mechanistic study
Authors: Morgan Kathleen M. , Brown Garry , Pichon Monique A. , Green Geannette Y.
Published: February 2011

The base‐induced rearrangement of aziridines has been examined using a combination of calculations and experiment. The calculations show that the substituent on nitrogen is a critical feature that greatly affects the favorability of both α‐deprotonation, and β‐elimination to form an allylic amine. Experiments were carried out to determine whether E2‐like rearrangement to the allylic amine with lithium diisopropyl amide (LDA) is possible. N‐tosyl aziridines were found to deprotonate on the tosyl group, preventing further reaction. A variety of N‐benzenesulfonyl aziridines having both α‐ and β‐protons decomposed when treated with LDA in either tetrahydrofuran or hexamethylphosphoramide. However, when α‐protons were not present, allylic amine was formed, presumably via β‐elimination. Copyright © 2011 John Wiley & Sons, Ltd.
IL‐10 inhibits inflammatory cytokines released by fetal mouse lung fibroblasts exposed to mechanical stretch
Authors: Hawwa Renda L. , Hokenson Michael A. , Wang Yulian , Huang Zheping , Sharma Surendra , Sanchez‐Esteban Juan
Published: February 2011

Background

Mechanical ventilation plays an important role in the pathogenesis of bronchopulmonary dysplasia. However, the molecular mechanisms by which excessive stretch induces lung inflammation are not well characterized.

Objectives

In this study, we investigated in vitro the contribution of lung mesenchymal cells to the inflammatory response mediated by mechanical stretch and the potential protective role of IL‐10.

Methods

Fetal mouse lung fibroblasts isolated during the saccular stage of lung development were exposed to 20% cyclic stretch to simulate mechanical injury. The phenotype of cultured fibroblasts was investigated by red oil O and alpha‐smooth muscle actin (α‐SMA) staining. Cell necrosis, apoptosis, and inflammation were analyzed by lactate dehydrogenase release, cleaved caspase‐3 activation and release of cytokines and chemokines into the supernatant, respectively.

Results

First, we characterized the phenotype of the cultured fibroblasts and found an absence of red oil O staining and 100% positive staining for α‐SMA, indicating that cultured fibroblasts were myofibroblasts. Mechanical stretch increased necrosis and apoptosis by two‐ and three‐fold, compared to unstretched samples. Incubation of monolayers with IL‐10 prior to stretch did not affect necrosis but significantly decreased apoptosis. Mechanical stretch increased release of pro‐inflammatory cytokines and chemokines IL‐1β, MCP‐1, RANTES, IL‐6, KC and TNF‐α into the supernatant by 1.5‐ to 2.5‐fold, and administration of IL‐10 before stretch blocked that release.

Conclusions

Our data demonstrate that lung interstitial cells may play a significant role in the inflammatory cascade triggered by mechanical stretch. IL‐10 protects fetal fibroblasts from injury secondary to stretch. Pediatr. Pulmonol. 2011; 46:640–649. © 2011 Wiley‐Liss, Inc.
Airway angiopoietin‐2 in ventilated very preterm infants: Association with prenatal factors and neonatal outcome
Authors: Thomas Wolfgang , Seidenspinner Silvia , Kramer Boris W. , Wirbelauer Johannes , Kawczyńska‐Leda Natalia , Szymankiewicz Marta , Speer Christian P.
Published: February 2011

Objective

Pulmonary angiogenesis is a prerequisite for lung development. Angiopoietin‐2 (Ang2) destabilizes endothelial cells through its endothelial receptor TIE‐2, enabling vascular sprouting. Ang1 stabilizes new blood vessels. Soluble TIE‐2 (sTIE‐2) modulates these effects. We hypothesized that histological funisitis is associated with alterations of Ang2 in airways and of the systemic angiopoietin‐TIE‐2 homeostasis in very low birth weight (VLBW) infants, contributing to pulmonary morbidity and mortality.

Methods

We measured Ang2 in tracheobronchial aspirate fluid (TAF) of 42 VLBW <30 weeks of gestation from day 1 through 15 and Ang1, Ang2, and sTIE‐2 in umbilical cord serum of 28 infants by enzyme‐linked immunosorbent assay. Histological examination distinguished three groups: funisitis, chorioamnionitis, and controls.

Results

Funisitis was associated with lower Ang2 values in TAF but not with changes of Ang1, Ang2, and sTIE‐2 in umbilical cord serum. Infants who developed bronchopulmonary dysplasia (BPD) or died had a persistently decreased ratio of previously measured Ang1 to Ang2 in TAF on days 1–5 and increased cord serum concentrations of sTIE‐2. Moderate BPD/death was associated with an increase of Ang2 in TAF on day 10 and decreased Ang1/Ang2 ratio from day 3–15. Small for gestational age (SGA) infants had increased Ang2 in TAF on day 1–7 and a lower Ang1/Ang2 ratio on days 5–7.

Conclusions

The predominance of Ang2 in airway fluid of infants with BPD/death and SGA infants suggests a link between disrupted placental and fetal pulmonary angiogenesis. Histological funisitis with reduced Ang2 in TAF was of minor relevance for outcome in our cohort. Pediatr. Pulmonol. 2011; 46:777–784. © 2011 Wiley‐Liss, Inc.
Repellency of a kaolin particle film to potato psyllid, Bactericera cockerelli (Hemiptera: Psyllidae), on tomato under laboratory and field conditions
Authors: Peng Linian , Trumble John T , Munyaneza Joseph E , Liu Tong‐Xian
Published: February 2011

BACKGROUND: The potato psyllid, Bactericera cockerelli, is a vector of Candidatus Liberibacter solanacearum, causing several diseases in solanaceous crops. Laboratory and field no‐choice and choice experiments were conducted to evaluate the repellency of kaolin particle film on adults of B. cockerelli on tomato plants that had been sprayed with kaolin particle film on the upper surface only, on the lower surface only and on both leaf surfaces.

RESULTS: In no‐choice tests in the laboratory, the numbers of adults on leaves were not different between the kaolin particle film and the water control, regardless of which leaf surface(s) were treated, but numbers of eggs were lower on the leaves treated with kaolin particle film than on those treated with water. In choice tests on plants treated with water/plants treated with kaolin particle film at ratios of 1:1, 6:3 or 8:1, fewer adults and eggs were found on the leaves treated with kaolin particle film than on leaves treated with water. Under field conditions, in caged no‐choice or choice tests, fewer adults, eggs and nymphs were found on plants treated with kaolin particle film than on plants treated with water. In an uncaged test under field conditions, plants sprayed with kaolin particle film had fewer psyllids than those sprayed with water.

CONCLUSION: Even though potato psyllid adults could land on plants treated with kaolin particle film when no choice was given, fewer eggs were laid. When given a choice, the psyllids avoided plants treated with kaolin particle film under laboratory and field conditions. Kaolin particle film treatment may be a useful alternative for management of potato psyllids under field conditions. Copyright © 2011 Society of Chemical Industry
Alanine scanning analysis and structure–function relationships of the frog‐skin antimicrobial peptide temporin‐1Ta
Authors: Grieco Paolo , Luca Vincenzo , Auriemma Luigia , Carotenuto Alfonso , Saviello Maria Rosaria , Campiglia Pietro , Barra Donatella , Novellino Ettore , Mangoni Maria Luisa
Published: February 2011

The increasing resistance of bacteria and fungi to the available antibiotic/antimycotic drugs urges for a search for new anti‐infective compounds with new modes of action. In line of this, natural CAMPs represent promising and attractive candidates. Special attention has been devoted to frog‐skin temporins, because of their short size (10–14 residues long) and their unique features. In particular, temporin‐1Ta has the following properties: (i) it is mainly active on Gram‐positive bacteria; (ii) it can synergize, when combined with temporin‐1Tl, in inhibiting both gram‐negative bacterial growth and the toxic effect of LPS; (iii) it preserves biological activity in the presence of serum; and (iv) it is practically not hemolytic. Rational design of CAMPs represents a straightforward approach to obtain a peptide with a better therapeutic index. Here, we used alanine scanning analogs to elucidate the contribution of the side chains of each amino acid residue to the peptide's antimicrobial and hemolytic activity. Beside providing insight into the biophysical attributes and the critical positions within the peptide sequence, which govern the antimicrobial/hemolytic activity of this temporin isoform, our studies assist in optimizing the design of temporin‐based lead structures for the production of new anti‐infective agents. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Continuous wavelength modulation of semi‐polar plane InGaN/GaN MQWs based on vapor‐phase‐diffusion‐based selective‐area pyramidal growth
Authors: Fujiwara Tatsuki , Nakano Yoshiaki , Sugiyama Masakazu
Published: February 2011

We have achieved continuous wavelength modulation from InGaN quantum wells on semi‐polar {11–22} planes with selective‐area growth of hexagonal pyramids with varied widths of masks surrounding them. The thickness of InGaN wells on the surface of the pyramids was tailored by the mask width, which led to wavelength modulation. The use of semi‐polar planes reduced quantum confined stark effect, allowing a wider range of wavelength modulation: from 446 to 500 nm as measured by cathode luminescence.
Autowave of electron population depletion and sub terahertz self‐modulations of light absorption and intrinsic stimulated emission in GaAs
Authors: Ageeva N. N. , Bronevoi I. L. , Zabegaev D. N. , Krivonosov A. N.
Published: February 2011

During picosecond photogeneration of electron‐hole plasma (EHP) in GaAs, intensive picosecond emission arises. Self‐modulations of light fundamental absorption and of emission characteristics are found out. These self‐modulations disclose origination in GaAs of wave of a new type, i.e., autowave of carrier populations depletion in energy space, a new type of collective excitation of carriers and a new form of EHP instability. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coherent control of electrical currents in semiconductor nanowires/‐tubes
Authors: Betz Markus , Ruppert Claudia , Thunich Sebastian , Newson Ryan , Ménard Jean‐Michel , Sames Christian , Abstreiter Gerhard , Fontcuberta i Morral Anna , Holleitner Alexander W. , van Driel Henry M.
Published: February 2011

Quantum interference control of electrical currents is well established in bulk semiconductors. It arises from the interference of one‐ and two‐photon absorption pathways. Here, the concept is transferred to one‐dimensional semiconductor nanostructures. First, currents are optically injected into aligned single‐walled carbon nanotube ensembles by phase‐related 700 and 1400 nm, 150 fs pulses. These transient currents are detected via the emitted THz radiation. In a second set of experiments, a phase‐stable superposition of ∼100 fs pulses from a compact erbium‐doped fiber source and their second harmonic is shown to induce ultrashort ∼µA current bursts in single unbiased GaAs nanowires. The current flow is characterized by charge accumulation and the related potential difference between the contacted ends of the ∼10 µm long wires. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Terahertz photoresponse dependence on magnetic and electric fields in graphene‐based devices
Authors: Salman M. , Gouider F. , Schmidt H. , Vasilyev Yu. B. , Haug R. J. , Nachtwei G.
Published: February 2011

In this study, the influence of a magnetic field on Landau levels (LLs) in graphene‐based devices is described via the magneto‐optical response induced by terahertz (THz) radiation. For single‐layer graphene, the resonance energies of the transitions between the LLs such as L1, L2 and L3, fit quite well to the terahertz spectral range.

The scattering rate of the spectral lines of LLs is taken into account. Based on a theoretical analysis we argue that the fingerprints of the THz radiation in single‐layer graphene can be improved to be observed at low magnetic fields. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Plasma‐related phonon‐sideband emission in semiconductors
Authors: Chernikov Alexej , Böttge Christoph N. , Feldtmann Thomas , Chatterjee Sangam , Koch Martin , Kira Mackillo , Koch Stephan W.
Published: February 2011

The phonon‐assisted recombination in bulk II‐VI semi‐conductors is analyzed by means of time‐resolved photoluminescence spectroscopy. Experimental results on both CdS and CdSe clearly indicate that phonon‐sideband emission is not exclusively attributed to the presence of excitons. The contributions of Coulombcorrelated electron‐hole plasma to the phonon assisted recombination may be significant, depending on the excitation conditions. This observation is supported by a microscopic many‐particle theory of interacting electrons, phonons, and photons. Our theoretical approach generalizes previous investigations by including both correlated and uncorrelated luminescence sources. Our findings contradict and expand the traditional picture of phonon‐sideband emission. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of motion on exciton magnetic properties
Authors: Kochereshko Vladimir P. , Davies John J. , Smith Lowenna C. , Wolverson Daniel , Mariette Henri , Boukari Hervé , Wiater Maciej , Karczewski Grzegorz , Wojtowicz Tomasz J.
Published: February 2011

In this paper we demonstrate that the magnetic moment of the exciton increases due to its motion along the magnetic field, and the diamagnetic shift decreases. These effects were observed for a set of quantum well structures with different well widths and based on a variety of semiconductor compounds. The reason for these effects is mixing of the exciton’s center of mass motion and the internal motion of the electron and hole in the exciton. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Coulomb correlations in quantum dots and their signatures in single dot femtosecond pump‐probe signals
Authors: Huneke J. , D'Amico I. , Machnikowski P. , Thomay T. , Bratschitsch R. , Leitensdorfer A. , Kuhn T.
Published: February 2011

We present a theoretical study of femtosecond pump‐probe experiments on a negatively charged single quantum dot and analyze the influence of Coulomb correlation effects on the lowest trion absorption line. The Coulomb correlated states as well as their corresponding oscillator strengths are calculated by a full diagonalization approach. The dynamics induced by the laser pulses are determined numerically by solving the Liouville‐von Neumann equation in the basis of the calculated few‐particle states. In agreement with the experiment, we demonstrate that Coulomb interactions and carrier relaxations noticeably affect the lowest trion absorption line. For negative and short positive delay times between pump and probe pulse instantaneous Coulomb renormalizations dominate the signal while for longer delay times the signal is governed by carrier relaxations. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Semiclassical theory for a nonequilibrium steady state in microcavity semiconductor lasers
Authors: Kamide Kenji , Ogawa Tetsuo
Published: February 2011

Semiclassical equations for microcavity semiconductor lasers based on Maxwell‐semiconductor‐Bloch equations are solved for on‐lasing state (nonequilibrium steady state) with a steady state condition for eigenfrequencies. Results for a single mode operation can account for input‐output curves for laser operation, gain saturation accompanied by the spectral hole‐burning in the carrier distribution, and the shift of laser frequency.

We found nonmonotonic dependency of the laser frequency on the pump intensity (excited carrier density) when the cavity mode is close to the exciton level. Effects of Coulomb interaction, and phase‐space filling are also discussed with reference to the case of homogeneously and inhomogeneously broadened two‐level atom lasers. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Silicon based light emitter utilizing tunnel injection of excess carriers via MIS structure
Authors: Arguirov Tzanimir , Wenger Christian , Lukosius Mindaugas , Mchedlidze Teimuraz , Reiche Manfred , Kittler Martin
Published: February 2011

We report on electro‐luminescence from metal‐insulator‐semiconductor diodes (MISLED). MISLEDs prepared on silicon with HfO2 layers of different thicknesses were investigated and their properties compared with such prepared by using SiO2 insulator layer. The role of the insulator layer was studied in view of the efficiency of the band‐to‐band radiation from silicon. We show that the luminescence efficiency depends on the dielectric constant of the insulator as well as on its ability to conduct carriers by tunnelling. Efficiency enhancement of 3.3 times was detected when the SiO2 insulator was substituted by HfO2 in the MIS emitter. Optimal injection current exists, which leads to a maximal efficiency of the luminescence. The optimal current depends strongly on the thickness of the oxide. We relate the existence of an optimal current with the depth at which the injected minority carriers recombine radiatively. Thus the electric field in the semiconductor and the surface recombination are the factors determining the optimal injection (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of dislocation behavior in Si‐ and C‐face 4H‐SiC
Authors: Chen Bin , Matsuhata Hirofumi , Sekiguchi Takashi , Ohyanagi Takasumi , Kinoshita Akimasa , Okumura Hajime
Published: February 2011

The dislocation behavior in C‐face 4H‐SiC homoepitaxial films was studied by using electron‐beam‐induced current (EBIC) technique and is compared with that in Si‐face ones. For the basal plane dislocations (BPDs) with the same line shape appearing in the EBIC images, the mobile partial dislocations (PDs) originated from the dissociation of such BPDs move in two opposite directions, while they move in one direction in the Si‐face samples. The difference of the PD movement between two faces is discussed (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Defect luminescence at grain boundaries in multicrystalline silicon
Authors: Dreckschmidt Felix , Möller Hans‐Joachim
Published: February 2011

Multicrystalline silicon is characterised by extended defects like dislocations and grain boundaries. Grain boundaries in this material can show radiative recombination in the near infrared (NIR) region even at room temperature (Dreckschmidt et al., Proc. 23rd European Photovoltaic Solar Energy Conference, Valencia, Spain, 2008, p. 407. [1]). Here we present results of further investigations by the electroluminescence method regarding these phenomena. It turned out that carrier recombination at these centres is negligible. From temperature dependent measurements activation energies of the different centres were determined. Defect schemes for the grain boundary luminescence are proposed (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fast electron beam charge injection and switching in dielectrics
Authors: Fitting Hans‐Joachim , Touzin Matthieu , Schreiber Erik
Published: February 2011

Basic investigations of secondary electrons (SE) relaxation and attenuation are made by means of Monte Carlo simulations using ballistic electron scattering and interactions with optical and acoustic phonons as well as impact ionization of valence band electrons. Then the electron beam induced selfconsistent charge transport and secondary electron emission in insulators are described by means of an electron‐hole flight‐drift model (FDM). Ballistic secondary electrons and holes, their attenuation and drift, as well as their recombination, trapping, and field‐ and temperature‐dependent Poole‐Frenkel detrapping are included. Whereas the initial switching‐on of the secondary electron emission proceeds over milli‐seconds due to long‐lasting selfconsistent charging, the switching‐off process occurs much faster, even over femto‐seconds.

Thus a rapid electron beam switching becomes possible with formation of ultra‐short electron beam pulses offering an application in stroboscopic electron microscopy and spectroscopy. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
EPR spectroscopy of weak exchange interactions between Co2+ ions in ZnO
Authors: Azamat D. V. , Dejneka A. , Trepakov V. A. , Jastrabik L. , Fanciulli M. , Ivanov V. Y. , Godlewski M. , Sokolov V. I. , Rosa J. , Badalyan A. G.
Published: February 2011

Electron paramagnetic resonance (EPR) is used to identify the next nearest neighbour Co2+ pairs coupled by spin–spin interaction in Co‐doped ZnO single crystals grown by the hydrothermal technique. These dimer centers are described by a spin Hamiltonian with exchange coupling terms written as interaction between identical effective spins Seff = 1/2 of the lowest ground state Kramers doublets of the two Co2+ ions. The exchange parameters of weakly ferromagnetically coupled next nearest neighbor Co2+ pairs are estimated. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Development of ice particles in convective clouds observed over the Black Forest mountains during COPS
Authors: Huang Yahui , Blyth Alan M. , Brown Philip R. A. , Cotton Richard , Crosier Jonathan , Bower Keith N. , Gallagher Martin W. , Jones Hazel , Gadian Alan M. , Choularton Tom W. , Cardwell John , Coe Hugh , Mobbs Stephen D. , Hagen Martin
Published: February 2011

A combination of modelling studies and ground‐based and aircraft measurements is used to examine the development of ice particles in convective clouds observed over the Black Forest mountains during the Convective and Orographically‐induced Precipitation Study (COPS). High concentrations of relatively small ice particles were observed in the weaker northern cell that developed on convergence lines over the mountains in the much‐studied 15 July 2007 case. The conditions in the cloud were not conducive for the Hallett–Mossop process. Instead, the explanation for such high concentrations of ice is likely associated with the type of ice nuclei ingested into the cloud. Biological nuclei, oxidised organic aerosol particles in the polluted air vented from the Murg valley into the cloud base, and desert dust are all possible candidates. A model sensitivity test with biological nuclei produced similar concentrations of ice particles to the observations. In contrast, the high concentration of ice particles measured in clouds that advected over the Black Forest mountains on 11 July 2007 were likely due to the Hallett–Mossop process. The deep convective cell at the southern end of the COPS domain on 15 July 2007 developed in less polluted air than the shallower northern cloud. A model sensitivity test with lower aerosol loading produced a more vigorous cloud with a higher top, more precipitation, and greater reflectivity, more similar to the radar observations. The results suggest that aerosol particles vented out of the valleys could have a significant impact on orographically induced precipitation. Copyright © 2011 Royal Meteorological Society and Crown copyright, the Met Office
The Convective and Orographically‐induced Precipitation Study (COPS): the scientific strategy, the field phase, and research highlights
Authors: Wulfmeyer Volker , Behrendt Andreas , Kottmeier Christoph , Corsmeier Ulrich , Barthlott Christian , Craig George C. , Hagen Martin , Althausen Dietrich , Aoshima Fumiko , Arpagaus Marco , Bauer Hans‐Stefan , Bennett Lindsay , Blyth Alan , Brandau Christine , Champollion Cédric , Crewell Susanne , Dick Galina , Di Girolamo Paolo , Dorninger Manfred , Dufournet Yann , Eigenmann Rafael , Engelmann Ronny , Flamant Cyrille , Foken Thomas , Gorgas Theresa , Grzeschik Matthias , Handwerker Jan , Hauck Christian , Höller Hartmut , Junkermann Wolfgang , Kalthoff Norbert , Kiemle Christoph , Klink Stefan , König Marianne , Krauss Liane , Long Charles N. , Madonna Fabio , Mobbs Stephen , Neininger Bruno , Pal Sandip , Peters Gerhard , Pigeon Grégoire , Richard Evelyne , Rotach Mathias W. , Russchenberg Herman , Schwitalla Thomas , Smith Victoria , Steinacker Reinhold , Trentmann Jörg , Turner David D. , van Baelen Joel , Vogt Siegfried , Volkert Hans , Weckwerth Tammy , Wernli Heini , Wieser Andreas , Wirth Martin
Published: February 2011

Within the framework of the international field campaign COPS (Convective and Orographically‐induced Precipitation Study), a large suite of state‐of‐the‐art meteorological instrumentation was operated, partially combined for the first time. This includes networks of in situ and remote‐sensing systems such as the Global Positioning System as well as a synergy of multi‐wavelength passive and active remote‐sensing instruments such as advanced radar and lidar systems. The COPS field phase was performed from 01 June to 31 August 2007 in a low‐mountain area in southwestern Germany/eastern France covering the Vosges mountains, the Rhine valley and the Black Forest mountains. The collected data set covers the entire evolution of convective precipitation events in complex terrain from their initiation, to their development and mature phase until their decay. Eighteen Intensive Observation Periods with 37 operation days and eight additional Special Observation Periods were performed, providing a comprehensive data set covering different forcing conditions. In this article, an overview of the COPS scientific strategy, the field phase, and its first accomplishments is given. Highlights of the campaign are illustrated with several measurement examples. It is demonstrated that COPS research provides new insight into key processes leading to convection initiation and to the modification of precipitation by orography, in the improvement of quantitative precipitation forecasting by the assimilation of new observations, and in the performance of ensembles of convection‐permitting models in complex terrain. Copyright © 2010 Royal Meteorological Society
Latent heat flux measurements over complex terrain by airborne water vapour and wind lidars
Authors: Kiemle Christoph , Wirth Martin , Fix Andreas , Rahm Stephan , Corsmeier Ulrich , Di Girolamo Paolo
Published: February 2011

Vertical profiles of the latent heat flux in a convective boundary layer (CBL) are obtained for the first time over complex terrain with airborne water vapour differential absorption lidar and Doppler wind lidar. During the Convective and Orographically‐induced Precipitation Study (COPS) over the Black Forest mountains in south‐western Germany both lidars were installed nadir‐viewing onboard the Falcon research aircraft of the Deutsches Zentrum für Luft‐ und Raumfahrt (DLR). On 30 July 2007, additional in situ measurements by the Karlsruhe Institute of Technology (KIT) were performed with a Dornier‐128 aircraft that flew below the Falcon. This unique instrument configuration allows us to validate the lidar‐derived fluxes and to assess lidar‐specific issues such as instrument noise and data gaps that impinge on the results. The cospectra of in situ humidity and vertical velocity peak at wavelengths between 1 and 3 km and reveal that the dominant scales of turbulent transport are larger than 700 m in dimension. Consequently the airborne lidars' horizontal and vertical resolution of ∼ 200 m is sufficient to capture most of the flux. The lidar and in situ fluxes of five collocated 45 km flight legs agree within ±20%; the average difference over the total distance of 225 km is 3%. A flux comparison with ground‐based water vapour Raman and wind lidars shows agreement within the instruments' accuracies under low‐wind conditions. All latent heat fluxes vary between 100 and 500 W/m2 in the CBL and have small vertical divergences. Vertical velocity spectra in the mid‐CBL enable us to estimate the dissipation rate of turbulent kinetic energy that amounts to 5 × 10−4 m2 s−3 in the Rhine Valley and 10−3 m2 s−3 over the Black Forest mountains. This new airborne lidar instrumentation proves to be a valuable tool for the study of CBL processes and variability, particularly over complex terrain. Copyright © 2011 Royal Meteorological Society
On stability analysis of systems featuring a multiplicative combination of nonlinear and linear time‐invariant feedback
Authors: Kulkarni Vishwesh V. , Pao Lucy Y. , Safonov Michael G.
Published: February 2011

We show that sufficient conditions for the finite‐gain stability of certain systems featuring a multiplicative combination of memoryless nonlinear feedback and linear time‐invariant feedback, as encountered in some systems' biology prototype applications, can be obtained by building on the Rantzer multipliers. These results are obtained by observing that for all finite energy signals x, the time‐truncated inner product 〈x, H(x)N(x)〉T is positive for all T>0 if N belongs to a subclass of positive memoryless monotone nonlinearities and if, in addition, H is a Rantzer multiplier. Copyright © 2011 John Wiley & Sons, Ltd.