bluuebunny/crossref_metadata_2025_split huggingface dataset:
p-Type δ-Doped Layers in GaAs Isolated by He+ Bombardment
Authors: Boudinov H. , Pesenti G. C. , Danilov I. , Zvonkov B N. 
Published: November 2007

Ion implantation is an essential process for production of modern III-V compound semiconductor devices and circuits and	has been proven as a successful method to convert a conductive layer into a highly resistive one. Due to its simplicity, precise depth control and compatibility with planar technologies, ion implantation is a potential alternative for mesa etching. Selective masking of the semiconductor surface with photoresist followed by ion irradiation is an efficient and practical way to isolate closely spaced devices.	Irradiation of GaAs by ions results in resistivity increase as a consequence of free carrier removal by trapping at defects	introduced by the irradiation. Delta-doping is a well known technique which spatially confines the dopants to one atomic layer during epitaxial growth of semiconductor materials. In the present work a dose dependence of sheet resistance of delta- doped GaAs structures, irradiated by He+ ions, was inve stigated. It was found that a threshold dose for electrical isolation of the structures was determined by the energy of ions and by the concentration of initial doping.
MEIS Study of Sb Implantation in O or N pre-implanted Si(001) and SIMOX
Authors: Dalponte M. , Boudinov H. , Goncharova L. V. , Garfunkel E. , Gustafsson T. 
Published: November 2007

Medium energy ion scattering (MEIS) was used to study distribution of ion-implanted Sb dopant in Si with excess vacancies and SIMOX substrates and the effects of thermal treatments. Extra vacancies in Si were generated by N or O pre-implantations at high temperature. Effects related to the different chemical nature of the pre-implanted species are expected under these conditions. Different Sb annealing behavior and distribution were observed for O and N pre-implanted Si. The oxygen containing samples (SIMOX and O pre-implanted Si) presented higher substitutionality after long annealing times. The nitrogen pre- implanted Si presented the lowest amount of segregated Sb and more uniform dopant distribution. Both pre-implanted samples, N and O, had a large dopant loss	to the atmosphere during annealing.
Transmittance Enhancement in Textured Silicon Solar Cells
Authors: de Lima Monteiro D. W. , Honorato F. P. , Nakamura L. , Tavares Branco J. R. , Freitas T. O. 
Published: November 2007

There is a growing demand to improve solar-cell efficiency. Among several methods under investigation, surface texturization is an important alternative. This paper presents an alternative texturization of crystalline silicon to improve solar-cell efficiency. The method is based on anisotropic etching of bulk silicon and requires only a single exposure mask and two etching steps with a KOH aqueous solution. The surface texture consists of smooth hemispherical cavities that have their parameters accurately controlled. There is no need for a lithographic mask or intricate technology processes to obtain the hemispherical cavities. By this method, it is possible to increase both the frontal surface exposed to light and the depletion region. That implies in a higher probability of photon collection, contributing to the improvement of the conversion efficiency of the device. The textured silicon solar-cell transmittance under small	incident angles during the day is improved compared to a flat surface, increasing the generated photocurrent.
Annealing Temperature Dependence of 1550 NM Emission of Hydrogenated Amorphous Silicon Films Co-Deposited with Erbium
Authors: Figueira D. , Mustafa D. , Tessler L. R. , Frateschi N. C. 
Published: November 2007

We present an experimental study of the influence of annealing temperature in the room temperature 1550 nm (~0.8eV) photoluminescence (PL) of Er3+ co-deposited with silicon on	silicon dioxide matrix to be used for light emission in microdisk resonators.
Structure and Optical Properties of ZnO Thin Films Prepared by Reactive e- Beam Evaporation
Authors: Sabino M. E. , Falcao V. D. , Muniz E , Diniz A. S. , Branco J. R. 
Published: November 2007

Zinc oxide has been used as transparent and conducting oxide film in solar cells and electrochromic devices. In this work, ZnO thin films have been deposited by reactive electron beam evaporation technique with	argonoxygen plasma assistance. The films have been deposited on glass	substrate. After the deposition, the films were annealed at 550ºC during 2 hours in an oxidant atmosphere to improve its optical properties. The films were characterized by atomic force microscopy, UV/VIS/NIR spectroscopy and X-ray diffraction. The films are adherent and	present high roughness, low transmittance and low crystallinity. After the thermochemical treatment there was an increase in optical transmittance, in crystallinity and a decrease of the absorption coefficient in the visible spectral region. Furthermore, the results of atomic force microscopy and DRX indicate that this treatment promotes a significant change of the surface texture and of the grain size.
Comparison of Plasma Parameters Obtained with Planar Probe and Optical Spectrometer
Authors: Swart L. , Daltrini A. M. , Moshkalyov S. A. , Verdonck Patrick 
Published: November 2007

A planar probe and an optical spectrometer were employed to analyze some parameters in an inductively coupled plasma (ICP). The analyses were performed in Ar, Ar+SF6 and O2 plasmas at 40 mTorr. Typical probe results indicate an ion current of 10-3 A/cm2 and an electron temperature (high energy tail) between 1-2 eV in measurements at high powers. At low powers a distinct discharge regime is observed, typically with	low density (low ion current) and high electron temperature. Even though a quantitative analysis has not been done yet, the optical	emission studies also showed the presence of these two regimes.
Study of Mode Transitions in Inductively Coupled Plasmas
Authors: Daltrini A. M. , Moshkalyov S. A. , Monteiro M. J. , Machida M. , Besseler E. 
Published: November 2007

The transitions between low density and high density modes in an inductively coupled plasma reactor were studied by the	measurements of different spectral line emissions in Ar plasmas. A described	model for metastable atoms shows that the ratio of the emissions Ar 811.5 nm / Ar 750.4 nm is similar to the contribution of metastable ionization in electron production (two-step ionization). Then, the influence of the metastable atoms in the transition triggering was identified, mainly at	high pressures. Also, the measurements show that metastable atoms can be a source for the sustaining of the H mode in the hysteresis region.
Effects of the Secondary Electron Emision Coefficent on the Generation of Charged Particles in RF Oxygen Discharge
Authors: Roberto Marisa , Verboncoeur John , Verdonck Patrick , Cizzoto Elias 
Published: November 2007

Radio-frequency oxygen discharges have several applications for plasma processing such as etching and surface modification. In	order to investigate the structure of O2 discharges between parallel plates at 13.56 MHz, we used the particle-in-cell plus	Monte Carlo collision model. A sustaining voltage of 500sinωt V	is used for pressures of 20 and 200 mTorr. The dominant process of generation of negative oxygen ions is dissociative attachment, while the loss processes are electron impact detachment, mutual neutralization and detachment. For 20 mTorr pressure processes, dominant positive and negative ions O2+ and	O- have a maximum density at the centre and the electron density is two orders of magnitude less than that of these	ions. However at a higher pressure, for the 200 mTorr case, the charge density profiles become broader. As the secondary electron emission from the electrodes increases, the electron density also increases as a result of high ionization rates.
Pim-1 and Pim-2 kinases are required for efficient pre–B-cell transformation by v-Abl oncogene
Authors: Chen Ji-Long , Limnander Andre , Rothman Paul B. 
Published: November 2007

AbstractThe precise mechanisms by which Abl oncogenes transform hematopoietic cells are unknown. We have examined the role of Pim kinases in v-Abl–mediated transformation. In v-Abl transformants, expression of Pim-1 and Pim-2, but not Pim-3, is dependent on Abl kinase activity. Transformation assays demonstrate that v-Abl cannot efficiently transform bone marrow cells derived from Pim-1−/−/Pim-2−/− mice. Ectopic expression of either Pim-1 or Pim-2 in Pim-1−/−/Pim-2−/− cells restores transformation by v-Abl, strongly suggesting that either Pim-1 or Pim-2 is required for v-Abl–mediated tumorigenesis. Interestingly, the combined deficiency of Pim-1, Pim-2, and Suppressor of Cytokine Signalling (SOCS)-1 resulted in partial restoration of v-Abl transformation efficiency. In addition, Pim kinases are involved in modification of SOCS-1 and in regulating SOCS-1 protein levels in v-Abl–transformed cells. Furthermore, Pim kinases regulate the proapoptotic proteins Bcl-XS and BAD. Pim kinases inhibit the expression of Bcl-XS. Pim deficiency decreases the phosphorylation levels of BAD, whereas ectopic expression of Pim-1 increases the amount of phospho-BAD. This correlates with an increased protection from apoptosis in Abl transformants expressing Pim kinases. Together, these data suggest that Pim kinases play a key role in the v-Abl transformation, possibly via participating in modulation of SOCS-1 and via regulating the apoptotic signaling.
Spleen tyrosine kinase Syk is critical for sustained leukocyte adhesion during inflammation in vivo
Authors: Frommhold David , Mannigel Ingrid , Schymeinsky Jürgen , Mocsai Attila , Poeschl Johannes , Walzog Barbara , Sperandio Markus 
Published: November 2007

AbstractBackgroundDuring inflammation, β2-integrins mediate leukocyte adhesion to the endothelium accompanied by the activation of the spleen tyrosine kinase Syk.ResultsWe investigated leukocyte adhesion and rolling in cremaster muscle venules before and during stimulation with fMLP using mice with aSyk-/-hematopoietic system. In unstimulated venules,Syk-/-leukocytes adhered less efficiently than control leukocytes while rolling was similar betweenSyk-/-and control leukocytes. During fMLP-superfusion, control mice showed significantly increased adhesion accompanied by reduced rolling. ForSyk-/-leukocytes, an increase in adhesion with a concomitant decrease in rolling was only observed during the first three minutes during fMLP stimulation, but not at later time points. We also investigated leukocyte spreading against the vessel wall during fMLP stimulation and found a significant impairment of spreading forSyk-/-leukocytes. Additional in vitro experiments revealed that the adhesion and spreading defect seen inSyk-/-chimeric mice was due to compromised β2-integrin-mediated outside-in signaling.ConclusionWe provide substantial evidence for an important role of Syk in mediating β2-integrin dependent outside-in signaling leading to sustained leukocyte adhesion and spreading during the inflammatory response in vivo.
Dynamic and redundant regulation of LRRK2 and LRRK1 expression
Authors: Biskup Saskia , Moore Darren J , Rea Alexis , Lorenz-Deperieux Bettina , Coombes Candice E , Dawson Valina L , Dawson Ted M , West Andrew B 
Published: November 2007

Abstract

Background
Mutations within the leucine-rich repeat kinase 2 (LRRK2) gene account for a significant proportion of autosomal-dominant and some late-onset sporadic Parkinson's disease. Elucidation of LRRK2 protein function in health and disease provides an opportunity for deciphering molecular pathways important in neurodegeneration. In mammals, LRRK1 and LRRK2 protein comprise a unique family encoding a GTPase domain that controls intrinsic kinase activity. The expression profiles of the murine LRRK proteins have not been fully described and insufficiently characterized antibodies have produced conflicting results in the literature.

Results
Herein, we comprehensively evaluate twenty-one commercially available antibodies to the LRRK2 protein using mouse LRRK2 and human LRRK2 expression vectors, wild-type and LRRK2-null mouse brain lysates and human brain lysates. Eleven antibodies detect over-expressed human LRRK2 while four antibodies detect endogenous human LRRK2. In contrast, two antibodies recognize over-expressed mouse LRRK2 and one antibody detected endogenous mouse LRRK2. LRRK2 protein resides in both soluble and detergent soluble protein fractions. LRRK2 and the related LRRK1 genes encode low levels of expressed mRNA species corresponding to low levels of protein both during development and in adulthood with largely redundant expression profiles.

Conclusion
Despite previously published results, commercially available antibodies generally fail to recognize endogenous mouse LRRK2 protein; however, several antibodies retain the ability to detect over-expressed mouse LRRK2 protein. Over half of the commercially available antibodies tested detect over-expressed human LRRK2 protein and some have sufficient specificity to detect endogenous LRRK2 in human brain. The mammalian LRRK proteins are developmentally regulated in several tissues and coordinated expression suggest possible redundancy in the function between LRRK1 and LRRK2.
Breastfeeding and childhood asthma: a six-year population-based cohort study
Authors: Fredriksson Pia , Jaakkola Niina , Jaakkola Jouni JK 
Published: November 2007

Abstract

Background
The question of the protective effect of breastfeeding on development of asthma has raised substantial interest, but the scientific evidence of the optimal duration of breastfeeding is controversial.

Methods
The authors elaborated the optimal duration of breastfeeding with respect to the risk of asthma primarily, and secondarily to the risk of persistent wheezing, cough and phlegm in school age in a population-based cohort study with the baseline in 1991 and follow-up in 1997. The study population comprised 1984 children aged 7 to 14 years at the end of the follow-up (follow-up rate 77). Information on breastfeeding was based on the baseline survey and information on the health outcomes at the follow-up.

Results
There was a U-shaped relation between breastfeeding and the outcomes with the lowest risk with breastfeeding from four to nine months for asthma and seven to nine months for persistent wheezing, cough and phlegm.

Conclusion
Our results suggest a U shape relation between duration of breastfeeding and risk of asthma with an optimal duration of 4 to 6 months. A true concave relation would explain the inconsistent results from the previous studies.
Carbohydrate restriction and dietary cholesterol modulate the expression of HMG-CoA reductase and the LDL receptor in mononuclear cells from adult men
Authors: Mutungi Gisella , Torres-Gonzalez Moises , McGrane Mary M. , Volek Jeff S. , Fernandez Maria Luz 
Published: November 2007

Abstract
The liver is responsible for controlling cholesterol homeostasis in the body. HMG-CoA reductase and the LDL receptor (LDL-r) are involved in this regulation and are also ubiquitously expressed in all major tissues. We have previously shown in guinea pigs that there is a correlation in gene expression of HMG-CoA reductase and the LDL-r between liver and mononuclear cells. The present study evaluated human mononuclear cells as a surrogate for hepatic expression of these genes. The purpose was to evaluate the effect of dietary carbohydrate restriction with low and high cholesterol content on HMG-CoA reductase and LDL-r mRNA expression in mononuclear cells. All subjects were counseled to consume a carbohydrate restricted diet with 10–15% energy from carbohydrate, 30–35% energy from protein and 55–60% energy from fat. Subjects were randomly assigned to either EGG (640 mg/d additional dietary cholesterol) or SUB groups [equivalent amount of egg substitute (0 dietary cholesterol contributions) per day] for 12 weeks. At the end of the intervention, there were no changes in plasma total or LDL cholesterol (LDL-C) compared to baseline (P > 0.10) or differences in plasma total or LDL-C between groups. The mRNA abundance for HMG-CoA reductase and LDL-r were measured in mononuclear cells using real time PCR. The EGG group showed a significant decrease in HMG-CoA reductase mRNA (1.98 ± 1.26 to 1.32 ± 0.92 arbitrary units P < 0.05) while an increase was observed for the SUB group (1.13 ± 0.52 to 1.69 ± 1.61 arbitrary units P < 0.05). Additionally, the LDL-r mRNA abundance was decreased in the EGG group (1.72 ± 0.69 to 1.24 ± 0.55 arbitrary units P < 0.05) and significantly increased in the SUB group (1.00 ± 0.60 to 1.67 ± 1.94 arbitrary units P < 0.05). The findings indicate that dietary cholesterol during a weight loss intervention alters the expression of genes regulating cholesterol homeostasis.
The Warwick-Edinburgh Mental Well-being Scale (WEMWBS): development and UK validation
Authors: Tennant Ruth , Hiller Louise , Fishwick Ruth , Platt Stephen , Joseph Stephen , Weich Scott , Parkinson Jane , Secker Jenny , Stewart-Brown Sarah 
Published: November 2007

Abstract

Background
There is increasing international interest in the concept of mental well-being and its contribution to all aspects of human life. Demand for instruments to monitor mental well-being at a population level and evaluate mental health promotion initiatives is growing. This article describes the development and validation of a new scale, comprised only of positively worded items relating to different aspects of positive mental health: the Warwick-Edinburgh Mental Well-Being Scale (WEMWBS).

Methods
WEMWBS was developed by an expert panel drawing on current academic literature, qualitative research with focus groups, and psychometric testing of an existing scale. It was validated on a student and representative population sample. Content validity was assessed by reviewing the frequency of complete responses and the distribution of responses to each item. Confirmatory factor analysis was used to test the hypothesis that the scale measured a single construct. Internal consistency was assessed using Cronbach's alpha. Criterion validity was explored in terms of correlations between WEMWBS and other scales and by testing whether the scale discriminated between population groups in line with pre-specified hypotheses. Test-retest reliability was assessed at one week using intra-class correlation coefficients. Susceptibility to bias was measured using the Balanced Inventory of Desired Responding.

Results
WEMWBS showed good content validity. Confirmatory factor analysis supported the single factor hypothesis. A Cronbach's alpha score of 0.89 (student sample) and 0.91 (population sample) suggests some item redundancy in the scale. WEMWBS showed high correlations with other mental health and well-being scales and lower correlations with scales measuring overall health. Its distribution was near normal and the scale did not show ceiling effects in a population sample. It discriminated between population groups in a way that is largely consistent with the results of other population surveys. Test-retest reliability at one week was high (0.83). Social desirability bias was lower or similar to that of other comparable scales.

Conclusion
WEMWBS is a measure of mental well-being focusing entirely on positive aspects of mental health. As a short and psychometrically robust scale, with no ceiling effects in a population sample, it offers promise as a tool for monitoring mental well-being at a population level. Whilst WEMWBS should appeal to those evaluating mental health promotion initiatives, it is important that the scale's sensitivity to change is established before it is recommended in this context.
National Trends in Emergency Department Antibiotic Prescribing for Children with Acute Otitis Media, 1996–2005
Authors: Fischer Thomas , Singer Adam J. , Lee Christopher , Thode Henry C. 
Published: November 2007

Objectives Withholding antibiotics in nontoxic children with acute otitis media (AOM) is now recommended to reduce bacterial resistance rates. Using the National Hospital Ambulatory Medical Care Survey (NHAMCS), the authors describe the national trends for prescribing antibiotics in children with AOM presenting to emergency departments (EDs) in the United States over the past decade. The authors hypothesized that the rates of prescribing antibiotics would decline over time. Methods This was a retrospective study of NHAMCS databases. A national sampling of ED visits for 1996–2005 was used to identify trends in ED prescription of antibiotics to patients with AOM. The National Drug Code Directory Drug Classes were used to identify type of antibiotic prescribed. Frequency and type of antibiotic prescription patterns over time were evaluated. Results There were 2.6 million and 2.1 million ED visits for AOM during the first and last years of the study. Children ages 2–12 years accounted for about 40% of all ED visits for AOM, with another 40% in the younger than 2 years age group and 20% in the older than 12 years of age group. During the first and last year of the study, 79.2% and 91.3% of the patients with AOM were prescribed antibiotics, respectively. There was a slight increasing trend in the proportion prescribed antibiotics over time (p = 0.02). The rates of use of antibiotics for AOM were similar in all three age groups. Conclusions There was a slight increase in the percentage of children with AOM who were prescribed antibiotics in the ED between 1996 and 2005. There was also no change in the patterns of prescribing antibiotics.
Curcumin Reduces Burn Progression in Rats
Authors: Singer Adam J. , McClain Steve A. , Romanov Alexander , Rooney Jean , Zimmerman Tom 
Published: November 2007

Objectives Cutaneous burns are dynamic injuries with a central zone of necrosis surrounded by a zone of ischemia. Conversion of this ischemic zone to full necrosis over the days following injury is due in part to highly reactive oxygen radicals. Curcumin is a component of the Oriental spice turmeric that has been shown to have antioxidant and antiapoptotic properties. The authors hypothesized that treatment of burns with curcumin would reduce the conversion of the ischemic zone to full necrosis. Methods This was a randomized controlled experiment. Twenty Sprague‐Dawley rats were used. Two burns were created on each animal's dorsum using a brass comb with four rectangular prongs preheated in boiling water and applied for 30 seconds, resulting in four rectangular 10 × 20–mm full‐thickness burns separated by three 5 × 20–mm unburned interspaces (zone of ischemia). Animals were randomized to curcumin or vehicle by oral gavage 30 minutes before injury and at 24, 48, and 72 hours after injury. Wounds were observed at one, two, and three days after injury for visual evidence of necrosis in the unburned interspaces. Full‐thickness biopsy specimens from the interspaces were evaluated with hematoxylin and eosin staining seven days after injury for evidence of necrosis. The percentage of interspaces that progressed to necrosis was compared with chi‐square tests. Results Forty comb burns with 120 unburned interspaces were created, evenly distributed between curcumin and vehicle alone. The percentage of interspaces that progressed to full‐thickness necrosis at one, two, three, and seven days after injury in the curcumin and vehicle groups were 30% versus 63% (p = 0.003), 30% versus 70% (p < 0.001), 63% versus 95% (p = 0.02), and 63% versus 95% (p = 0.02), respectively. Conclusions Pretreatment of rats with oral curcumin followed by once‐daily oral treatment for three days reduced the percentage of unburned skin interspaces that progressed to full necrosis.