bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety and Efficacy of Temporal Manual Small Incision Cataract Surgery in India
Authors: Zawar Swati V. , Gogate Parikshit
Published: April 2011

Purpose.

To assess safety and efficacy of temporal manual small incision cataract surgery (SICS) in context to visual outcome, astigmatism, and complications.

Methods.

This involved sclerocorneal tunnel, capsulotomy and hydrodissection. The incision was made with number 11 disposable surgical blade (costing Indian Rs. 2.50, $0.05). Nucleus extraction was done by phaco-sandwich method with the help of vectis and dialer. Posterior chamber intraocular lens implantation was done according to biometric findings. A record of intraoperative and postoperative complications was made. The final postoperative assessment of astigmatism was done with spectacle correction on the 45th day as per the refraction findings.

Results.

Two thousand eyes were operated by temporal, manual small incision sutureless technique. Uncorrected visual acuity was ≥6/18 in 1636 (81.7%) patients on the first postoperative day, in 1652 (82.6%) patients at 2 weeks, and in 1732 (88.6%) patients at 6 weeks. Best-corrected visual acuity (BCVA) ≥6/18 was achieved in 1868 (93.4%) patients at 6 weeks, with 46 (2.3%) having BCVA <6/60, 24 (1.2%) of whom had preexisting retinal pathology. At 6 weeks, 1876 (93.8%) eyes had with-the-rule and 134 (6.2%) against-the-rule astigmatism (mean 0.7±1.25 D). Iris prolapse was noted in 3 (0.15%), wound leak in 3 (0.15%), and transient corneal edema in 136 (6.8%) eyes. Average surgery time was 6 minutes.

Conclusions.

Temporal SICS with number 11 disposable surgical blade and nucleus delivery by phaco-sandwich method gave excellent outcome with minimal astigmatism and low complication rate at economic cost.
Late Laceration of the Superficial Femoral Artery by an Intertrochanteric Fracture Fragment
Authors: Tomčovčík L'uboš , Kováč Pavol , Daňo Jaroslav , Čuha Radoslav
Published: April 2011

Injury to the femoral vessels is a rare complication after intertrochanteric fractures, and usually involves the profunda femoris artery. We report the case of a 79-year-old male with an intertrochanteric fracture, treated by closed antegrade intramedullary nailing, which was complicated by late injury to the superficial femoral artery 5 weeks after surgery. The injury was caused by a spike of bone from the anteriorly displaced lesser trochanter fragment. Direct suture of the injured artery was possible without subsequent complications.
Design and Development of a New Automated and High-Speed Gas Filling Systems
Authors: Li Zheng (Jeremy)
Published: April 2011

This research is to describe the recent development of a new automated and high-speed gas filling system in industrial applications. It aims at the introduction, study, and analysis of automated and high-speed gas filling mechanisms in industry. Automation is not only significantly increasing the production speed but also more accurately controlling product quality. Automated mechanical system can maintain consistent quality, shorten lead time, simplify material handling, optimize work flow, and meet the product demand for flexibility and convertibility in production. Computer-aided engineering design can quickly model automated machinery systems, shorten the product development cycles, and improve engineering integral processes of product design, development, engineering analysis, and production. This paper introduces a newly developed automated and high-speed gas filling system and focuses on computer-aided design, modeling, and simulation of this new mechanism. Compared with the current conventional systems, this new automated gas filling system has more reliable sealing function and higher production rates. The prototype of this automated machinery system has also been tested for functional verification. Both computer-aided analysis and prototype testing results indicate that this automated and high-speed gas filling mechanical system works well with high production quantity and reliable product quality.
Impact of Inflammatory Bowel Disease upon Growth in Children and Adolescents
Authors: Moeeni V. , Day A. S.
Published: April 2011

The inflammatory bowel diseases (IBDs) are chronic inflammatory processes affecting the gastrointestinal tract. When diagnosed in childhood and adolescence, IBD almost always impacts adversely upon the nutritional state of the patient. Weight loss and impaired linear growth may be present at diagnosis or subsequently. Further potential nutritional consequences in childhood IBD include malnutrition, anaemia, osteopaenia, and delayed puberty. Understanding the nutritional aspects of IBD is paramount in growing children, especially those entering and advancing through puberty. This paper focuses upon the nutritional impacts of IBD in children and adolescents.
Carer burden in apathy and impulse control disorders in Parkinson's disease
Authors: Leroi Iracema , Harbishettar Vijay , Andrews Michelle , McDonald Kathryn , Byrne E. Jane , Burns Alistair
Published: April 2011

Background

The neuropsychiatric complications of Parkinson's disease (PD), which include behaviour disturbances such as apathy and the impulse control disorders (ICDs), may have a significant effect on patients with PD and their carers. The contribution of these behaviour disorders to carer burden is less understood. Therefore, the aim of this study was to explore the relationship that apathy and ICDs have with carer burden.

Methods

Non‐demented (n = 71) PD–carer dyads (spouse or adult child) participated in the study. The PD participants were divided into three behavioural groups: ICD (n = 21), apathy (n = 22) and controls (n = 28). The three groups were compared for level of burden in their carers by using the Zarit Burden Interview. The PD participants were rated for levels of apathy, impulsivity and motor and psychiatric symptoms. Using a multivariate analysis, we sought the PD‐related predictors of carer burden.

Results

Significantly, greater burden was seen in carers of PD participants with ICDs (p = 0.002) or apathy (p = 0.004), compared with carers of PD participants without such behavioural disturbances. Linear regression models revealed that attentional ability accounted for burden in carers of the group with apathy, whereas dopaminergic load and depression accounted for burden in carers of the group with impulsivity.

Conclusion

PD‐related behaviour disturbances, such as apathy and ICDs, as well as psychiatric complications, have significant negative implications for burden of care. Copyright © 2011 John Wiley & Sons, Ltd.
Minimal residual disease detection in lymphoma and multiple myeloma: impact on therapeutic paradigms
Authors: Ferrero Simone , Drandi Daniela , Mantoan Barbara , Ghione Paola , Omedè Paola , Ladetto Marco
Published: April 2011

Early identification of patients at high risk of relapse is a major goal of current translational research in oncohematology. Minimal residual disease (MRD) detection by polymerase chain reaction‐based methods is currently part of the routine clinical management of patients with acute lymphoblastic leukemia. However, the current knowledge indicates that it is also a useful prognostic tool in several mature lymphoproliferative disorders. Its utility is currently well established in follicular lymphoma, mantle cell lymphoma, and multiple myeloma. In some of these entities, clinical trials employing MRD as a decision‐making tool are currently ongoing. In the present review, we will discuss the ‘state of the art’ of MRD evaluation in these three neoplasms with the ultimate aim of providing critical take‐home messages for clinicians working in the field. Moreover, we will outline the role of MRD detection in the design of future clinical trials. Copyright © 2011 John Wiley & Sons, Ltd.
Non‐steroidal anti‐inflammatory drugs and risk of pulmonary embolism
Authors: Biere‐Rafi Sara , Di Nisio Marcello , Gerdes Victor , Porreca Ettore , Souverein Patrick , de Boer Anthonius , Büller Harry , Kamphuisen Pieter
Published: April 2011

Purpose Non‐steroidal anti‐inflammatory drugs (NSAIDs) have been associated with an increased risk of arterial thrombosis, but their effect on venous thrombotic events is less well established. The study aimed to assess the risk of symptomatic pulmonary embolism (PE) in patients using NSAIDs and to evaluate any effect of type, dose, and duration of therapy.

Methods A case–control study was conducted using the PHARMO Record Linkage System, a Dutch population‐based registry. Cases were patients hospitalized with a primary diagnosis of PE and were matched to controls without a history of PE. To exclude confounding by indication, the effect of painkillers without known hemostatic effects was assessed.

Results The study population consisted of 4433 cases and 16 802 controls. After adjustment for surgery, trauma, and malignancy, current use of NSAIDs was associated with PE (odds ratio (OR) 2.39, 95% confidence interval (CI) 2.06–2.77). The risk was highest for traditional NSAIDs, and the overall risk for NSAIDs was highest in the first 30 days of exposure (OR 4.77, 95%CI 3.92–5.81), as compared with chronic (<1 year; OR 1.83, 95%CI 1.47–2.28) or long‐term use (>1 year; OR 2.14, 95%CI 1.48–3.09). Use of acetaminophen and tramadol also increased the risk of PE (OR 1.74, 95%CI 1.42–2.14 and OR 4.07, 95%CI 2.86–5.75, respectively) with a similar time trend.

Conclusions Use of NSAIDs is associated with an increased risk of symptomatic PE. This association may be partially explained by underlying medical conditions, as suggested by a similarly increased thrombotic risk in patients receiving acetaminophen and tramadol. Copyright © 2011 John Wiley & Sons, Ltd.
rhKGF stimulates lung surfactant production in neonatal rats in vivo
Authors: Gesche Jens , Fehrenbach Heinz , Koslowski Roland , Ohler Florian M. , Pynn Christopher J. , Griese Matthias , Poets Christian F. , Bernhard Wolfgang
Published: April 2011

Surfactant deficiency and bronchopulmonary dysplasia (BPD), major obstacles in preterm infants, are addressed with pre‐ and postnatal glucocorticoids which also evoke harmful catabolic side‐effects. Keratinocyte growth factor (KGF) accelerates surfactant production in fetal type II pneumocytes (PN‐II), protects epithelia from injury and is deficient in lungs developing BPD, highlighting its potential efficacy in neonates. Neonatal rats were treated with recombinant human (rh)KGF, betamethasone, or their combination for 48 hr prior to sacrifice after which body weight, surfactant, and tissue phosphatidylcholines (PC) were investigated at postnatal d3, d7, d15, and d21. Pneumocyte proliferation, surfactant protein (SP) expression and SP‐B/C in lung lavage fluid (LLF) were also determined at d7 and d21 to identify broader surfactant changes occurring at the beginning and end of the initial alveolarization phase. While all treatments increased secreted surfactant PC, BM compromised animal growth whereas rhKGF did not. At d3 rhKGF was more effective in male compared to female rats. Single treatments became less effective towards d21. Neither treatment altered PC composition in LLF. BM inhibited PN‐II proliferation and increased surfactant PCs at the expense of tissue PCs. rhKGF however increased surfactant PCs without decreasing other PC species. Whereas SP‐B/C gene expression was induced by all treatments, the changes in secreted SP‐B/C mirrored those observed for surfactant PC. Our results encourage investigation of the mechanisms by which rhKGF improves surfactant homoeostasis, and detailed examination of its efficacy in neonatal lung injury models with a view to implementing it as a non‐catabolic surfactant‐increasing therapeutic in neonatal intensive care. Pediatr. Pulmonol. 2011; 46:883–895. © 2011 Wiley‐Liss, Inc.
A method for identifying otological drill milling through bone tissue wall
Authors: Cao Tianyang , Li Xisheng , Gao Zhiqiang , Feng Guodong , Shen Peng
Published: April 2011

Background

Otological drill milling through the bone tissue wall is a common milling fault in ear surgery. This paper presents a method for identifying milling faults and improving operation safety.

Methods

Force and current sensors are used. According to a DC motor model and a cutting force model, the features of the milling process were analysed and a dynamic model was established. The dynamic model could extract the characteristic curve of a milling fault and the phase difference between the current and force signals. An adaptive filter was designed to fuse the phase and amplitude of signals to suppress interference in the characteristic curve. According to the filtering result, milling states can be identified by a rule base.

Results

Five surgeons carried out experiments on calvarian bone. The average recognition rate of milling faults was 90%. Only 1% of normal millings were identified as milling faults.

Conclusions

This method could be adapted to different surgeons and identify milling faults exactly. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation of flexible endoscope steering using haptic guidance
Authors: Reilink Rob , Stramigioli Stefano , Kappers Astrid M.L. , Misra Sarthak
Published: April 2011

Background

Steering the tip of a flexible endoscope relies on the physician's dexterity and experience. For complex flexible endoscopes, conventional controls may be inadequate.

Methods

A steering method based on a multi‐degree‐of‐freedom haptic device is presented. Haptic cues are generated based on the endoscopic images. The method is compared against steering using the same haptic device without haptic cues, and against conventional steering. Human‐subject studies were conducted in which 12 students and 6 expert gastroenterologists participated.

Results

Experts are significantly faster when using the conventional method compared with using the haptic device, either with or without haptic cues. However, it is expected that the performance of the subjects with the haptic device will increase with experience.

Conclusions

Using a haptic device may be a viable alternative to the conventional method for the control of complex flexible endoscopes. The results suggest that the use of haptic cues may reduce the patient discomfort. Copyright © 2011 John Wiley & Sons, Ltd.
Mild Method for Preparation of 4,4‐Dimethyloxazoline Derivatives of Polyunsaturated Fatty Acids for GC–MS
Authors: Svetashev Vasily I.
Published: April 2011

A mild and convenient method has been developed for preparing 4,4‐dimethyloxazoline (DMOX) derivatives of fatty acids for GC–MS analysis. First, fatty acid methyl esters are converted to corresponding amides by incubation overnight at room temperature with 2‐amino‐2‐methyl‐1‐propanol and a catalytic amount of sodium methoxide. The resulting 2‐(methylpropanol) amides were isolated by partition between hexane–diethyl ether and water, and then converted to 4,4‐dimethyloxazoline derivatives by treatment with trifluoroacetic anhydride under mild conditions (50 °C for 45 min). Structures of 2‐methylpropanol amide and a DMOX derivative of oleic acid were confirmed by GC–MS. This method was applied to different FAME prepared from animal, plant or microbial lipids. The suggested method is most suitable for structure analysis of polyunsaturated fatty acids (PUFA) and for acids with double bonds in close to terminal positions. Application of the method is illustrated with spectra of the DMOX derivatives of 16:1(n‐13), 24:5(n‐6) and 24:6(n‐3) acids.
PGE2 Release from Tryptase‐Stimulated Rabbit Ventricular Myocytes is Mediated by Calcium‐Independent Phospholipase A2γ
Authors: Sharma Janhavi , McHowat Jane
Published: April 2011

Inflammation is associated with cardiovascular disease, including myocardial infarction, atherosclerosis, myocarditis and congestive heart failure. Mast cells have been implicated in inflammation, but their precise role in cardiac inflammation remains unclear. Mast cells contain a variety of pre‐formed granule‐associated mediators, including tryptase. We have previously demonstrated that the majority of the phospholipase A2 (PLA2) activity in isolated rabbit ventricular myocytes is membrane‐associated, calcium‐independent and selective for plasmalogen phospholipids. We hypothesized that tryptase stimulation of rabbit ventricular myocytes would increase iPLA2 activity, leading to increased arachidonic acid and prostaglandin E2 (PGE2) release. Isolated rabbit ventricular myocytes were stimulated with tryptase and iPLA2 activity, arachidonic acid and PGE2 release were measured. Tryptase stimulation increased iPLA2 activity after 5 min. Activation of iPLA2 was accompanied by increased arachidonic acid and PGE2 release in tryptase‐stimulated myocytes. However no increase in platelet activating factor was observed with tryptase stimulation. To distinguish between different iPLA2 isoforms in the myocardium, we pretreated ventricular myocytes with the (R)‐ and (S)‐enantiomers of bromoenol lactone (BEL) to selectively inhibit iPLA2γ and β respectively. Pretreatment with (R)‐BEL resulted in complete inhibition of tryptase‐stimulated iPLA2 activity, arachidonic acid and PGE2 release, suggesting the iPLA2γ is the predominant myocardial isoform activated by tryptase. These studies demonstrate that PGE2 release from tryptase stimulated rabbit ventricular myocytes is mediated primarily by iPLA2γ.
Application of a Portable Handheld Infrared Spectrometer for Quantitation of trans Fat in Edible Oils
Authors: Birkel Emily , Rodriguez‐Saona Luis
Published: April 2011

Trans fat poses serious health risks to consumers. In order to meet the FDA labeling requirements for trans fatty acids, development of fast, accurate, easy‐to‐use analytical methods for oils, fats and related products is desirable. Fourier transform infrared spectroscopy (FTIR) is a well‐established analytical technique for quantifying trans fats, and the development of handheld FTIR units over the past decade presents new application opportunities. Our objective was to evaluate the performance of a handheld FTIR sensor for measuring trans fat content between 0.1 and 20% trans (w/w) in edible saturated and unsaturated oils. Calibration models were built by measuring height of the band at 966 cm−1 and by partial least squares regression (PLSR) using benchtop FTIR as a reference method. Predictive accuracy of the models was validated with an independent test set of commercial edible oils. Calibration models developed using PLSR and linear regression of band heights gave correlation coefficients R2 > 0.98. Multivariate analysis for the handheld unit gave standard error of prediction (SEP) of approximately 1%, comparable to values obtained with benchtop systems. This study demonstrates that handheld FTIR spectroscopy coupled with chemometrics is a suitable method for quantitation of trans fat content.
Crystallization of Fats: Influence of Minor Components and Additives
Authors: Smith Kevin W. , Bhaggan Krish , Talbot Geoff , van Malssen Kees F.
Published: April 2011

Over the years, there has been a steady stream of publications on the influence that minor components and additives have on the physical properties of fat continuous systems. These have been reviewed here. Both indigenous and added components are taken into account. The various materials have been discussed, ranging from partial glycerides and phospholipids to esterified sugars and polyols. Within the publications in this area, the (sub‐)micron effects that these minor components have on nucleation, crystal growth, morphology, heat capacity and polymorphic stability have been described and discussed and, sometimes, explained. Similarly, the effects on a macroscopic level, such as visual aspects, melting profiles, post‐hardening and rheology have been the subject of research. Although limited compositional information, especially of additives, hinders appropriate discussions of the relevant mechanisms, some generic guidelines as to what type and strength of effect can be expected have been derived. As a general rule, a more significant influence is observed when the acyl group of the minor component (where present) is similar to those present in the fat itself. Additives may have different effects depending on the fat they are added to, their concentration and the temperature, especially with increasing undercooling (which typically reduces the effect of additives).
Technical principles of computed tomography in patients with congenital heart disease
Authors: Stinn Bjoern , Stolzmann Paul , Fornaro Juergen , Hibbeln Dennis , Alkadhi Hatem , Wildermuth Simon , Leschka Sebastian
Published: April 2011

Cardiac magnetic resonance imaging and echocardiography are often the primary imaging techniques for many patients with congenital heart disease (CHD). However, with modern generations of CT systems and recent advances in temporal and spatial resolution, cardiac CT has been gaining an increasing reputation in the field of cardiac imaging and in the evaluation of patients with congenital heart disease. The CT imaging protocol depends on the suspected cardiac defect, the type of previous surgical repair, and the patient’s age and level of cooperation. Various strategies are available for reducing radiation exposure, which is of utmost importance particularly in paediatric patients. A sequential segmental analysis is a commonly used approach to analysing congenital heart defects. Familiarity of the performing radiologist with dedicated CT protocols, the complex anatomy, morphology and terminology of CHD, as well as with the surgical procedures used to correct congenital abnormalities is a prerequisite for correct diagnosis.
ADP‐ribosylation of histones by ARTD1: An additional module of the histone code?
Authors: Hottiger Michael O.
Published: April 2011

ADP‐ribosylation is a covalent post‐translational protein modification catalyzed by ADP‐ribosyltransferases and is involved in important processes such as cell cycle regulation, DNA damage response, replication or transcription. Histones are ADP‐ribosylated by ADP‐ribosyltransferase diphtheria toxin‐like 1 at specific amino acid residues, in particular lysines, of the histones tails. Specific ADP‐ribosyl hydrolases and poly‐ADP‐ribose glucohydrolases degrade the ADP‐ribose polymers. The ADP‐ribose modification is read by zinc finger motifs or macrodomains, which then regulate chromatin structure and transcription. Thus, histone ADP‐ribosylation may be considered an additional component of the histone code.
Synthesis of annulated thiophene perylene bisimide analogues: their applications to bulk heterojunction organic solar cells
Authors: Choi Hyunbong , Paek Sanghyun , Song Juman , Kim Chulwoo , Cho Nara , Ko Jaejung
Published: April 2011

Annulated thiophene perylene bisimides and their triphenyl-amine based oligomers have been synthesized. One of the oligomers FPTTPA has been demonstrated to be an efficient electron donor in bulk heterojunction (BHJ) organic solar cells, giving a power conversion efficiency of 1.42%.
A reaction-based chromogenic and fluorescent chemodosimeter for fluoride anions
Authors: Fu Li , Jiang Feng-Lei , Fortin Daniel , Harvey Pierre D. , Liu Yi
Published: April 2011

An innovative trihexylsilylacetylene-containing BODIPY dye was designed and proved to be a highly selective, sensitive, and fast chromogenic and fluorescent chemodosimeter for fluorides.
Three-sided magnets for magnetic resonance imaging
Authors: Bertora F. , Fabbricatore P. , Viale A. , Borceto A.
Published: April 2011

The quest for open MRI magnets has so far been satisfied by designs that can be re-conduced to “C” or “H” configurations, whose cavities can be described as “two sided,” meaning that two surfaces only are actively generating the magnetic field in the region of interest. The low efficiency of these magnets can be increased giving an active role to the “third wall” of the cavity. We present here a configuration involving only planar coils. This layout avoids excessive folding and torsion of the wire and reduces the effect of the mechanical forces produced by the magnetic field.
Note: Analysis of the efficiency of a dielectric elastomer generator for energy harvesting
Authors: Kang Gyungsoo , Kim Kyung-Soo , Kim Soohyun
Published: April 2011

In this study, a dielectric elastomer (DE) generator is developed for micropower generation, and its efficiency is derived. It is shown explicitly that power generation efficiency depends on the thickness of the DE generator, the charging voltage, the effective stiffness of the DE generator, the dielectric constant, and the relative deformation. Through experiments with VHB™ 4905 film, the proposed analysis is verified. In particular, the effective stiffness of a DE generator inversely improves the power generation efficiency.
Microstructure, magnetic, and magnetoimpedance properties of electrodeposited NiFe/Cu and CoNiFe/Cu wire: A study on influence of saccharin additive in plating bath
Authors: Mishra Amaresh Chandra , Sahoo Trilochan , Srinivas V. , Thakur Awalendra K.
Published: April 2011

Magnetic thin films of NiFe and CoNiFe were electrodeposited from three different deposition baths on copper wires of 100 μm diameter. The magnetic and magneto-impedance (MI) properties of the samples were investigated as a function of saccharin additive concentration in the plating bath. For all intermediate frequencies, the MI ratio increased with saccharin concentration in the plating bath up to a critical concentration and then saturates. The change in MI with saccharin concentration in electrodeposition bath was attributed to the grain size reducing action of saccharin which in turn reduces the coercivity of the film, making it soft magnetic. The origin of MI lies in the combined effect of domain wall motion and spin rotation which contributes to permeability. Inductance spectroscopy was used to evaluate the magnetic characteristic of the samples by modeling magnetic film-coated wires in terms of equivalent electrical circuit; namely parallel inductance and resistance circuit in series with series A circuit. The domain wall motion was found to be greatly affected by saccharin addition to the bath, which was revealed through the study of variations in these circuit parameters. The domain wall motion thereby affects the magnetic softness of samples, which is reflected by MI enhancement.
Spectroscopy of electronic thermal noise as a direct probe of absolute thermoelectric coefficients
Authors: Garrity Patrick L.
Published: April 2011

The utilization of thermal fluctuations or Johnson/Nyquist noise as a generalized spectroscopic technique to experimentally measure transport properties is applied to Pt and W metal films. Through cross-correlation and autocorrelation functions obtained from voltage power spectral density measurements, multiple transport coefficients are obtained through the Green–Kubo formalism. Supported rigorously by the underlying fluctuation-dissipation theorem and Green–Kubo transport theory, this novel experimental technique provides a direct measurement of absolute Seebeck and Peltier coefficients in addition to the electrical resistivity, electronic contribution to thermal conductivity, and Lorenz number. This work reports the validation results of the experiment accomplished through the use of materials with thermoelectric properties widely accepted by the thermoelectric community, Pt and W. Further validation of the data was accomplished by comparing the resistivity results to standard collinear four-probe resistivity measurements. Spectroscopic results for resistivity at 300 K resulted in 5.3% and 2.5% agreement with four-probe resistivity measurements for Pt and W, respectively. The Seebeck coefficient measurements at 300 K showed agreement with published values within 3.8% and 7.5% for Pt and W, respectively. The electronic thermal conductivity measured 66% and 75% of the total thermal conductivity for Pt and W, respectively, at 300 K.
Ion distribution measurements to probe target and plasma processes in electronegative magnetron discharges. I. Negative ions
Authors: Welzel Th. , Naumov S. , Ellmer K.
Published: April 2011

Mass and energy spectra of negative ions in magnetron sputtering discharges have been investigated with an energy-dispersive mass spectrometer. The dc magnetrons have been operated in the same reactive Ar/O2 atmosphere but with three different target materials: Cu, In, and W. Besides negative ions of the working gas, a variety of target metal containing negative molecular ions were found in the discharge. Their occurrence is strongly dependent on the target material. It has been correlated to the electron affinity and the bond strength of the molecules which has been calculated by density functional theory. Energy spectra of the negative ions exhibit three contributions that are clearly distinguishable. Their different origin is discussed as electron attachment in the gas phase and at the target surface, and molecule fragmentation during transport from target to substrate. The latter two contributions again significantly deviate for different target material. The high-energy part of the spectra has been analyzed with respect to the energy the particles gain upon release from the surface. It suggests that bigger molecules formed on the surface are released by ion-assisted desorption.
Ion distribution measurements to probe target and plasma processes in electronegative magnetron discharges. II. Positive ions
Authors: Welzel Th. , Naumov S. , Ellmer K.
Published: April 2011

Spectra of the ion mass and energy distributions of positive ions in reactive (Ar/O2) and nonreactive (Ar) dc magnetron sputtering discharges have been investigated by energy-resolved mass spectrometry. The results of three sputter target materials, i.e., Cu, In, and W are compared to each other. Besides the main gas constituents, mass spectra reveal a variety of molecular ions which are dependent on the target material. In reactive mode, ArO+ is always observed in Ar/O2 but molecules containing Ar and the metal were exclusively found for the Cu target. The occurrence of the different ions is explained in the context of their bond strengths obtained from density functional theory calculations. The energy spectra generally contain the known low-energy peak corresponding to the plasma potential. Differently extended high-energy tails due to sputtered material were observed for the different targets. Besides these, high-energetic ions were detected with up to several 100 eV. Their energies are significantly different for Ar+ and O+ with Ar+ strongly depending on the target material. The spectra are discussed together with results from transport of ions in matter (TRIM) calculation to elucidate the origin of these energetic ions.
A basic study of a triangular magnet chain for locomotion control
Authors: Kim Sung Hoon , Hashi Shuichiro , Ishiyama Kazushi
Published: April 2011

This paper introduces a theoretical (magnetic and robotic) and experimental study of a robotic locomotion principle utilizing a triangular artificial magnetic chain with a rotating magnetic field for biomedical applications. A three-axis Helmholtz coil system with external controller (joystick) controls the moving direction of the proposed magnet chain according to changes of the plane of the rotating magnetic field. The proposed magnet chain consists of three NdFeB magnets, and its magnetic property depends on dipoles interaction. Also, motion dynamics bring about a magnetic torque analyzed by robotics. A total magnetic moment on the triangular magnet chain provides magnetic torque in the rotating magnetic field, and a geometric property produces a stable movement for robotic locomotion.
Thermodynamics and kinetics of silicon under conditions of strong electronic excitation
Authors: Shokeen Lalit , Schelling Patrick K.
Published: April 2011

We present a detailed analysis of a recently-developed empirical potential to describe silicon under conditions of strong electronic excitation. The parameters of the potential are given as smooth functions of the electronic temperature Te, with the dependence determined by fitting to finite-temperature density-functional theory calculations. We analyze the thermodynamics of this potential as a function of the electronic temperature Te and lattice temperature Tion. The potential predicts phonon spectra in good agreement with finite-temperature density-functional theory, including the previously predicted lattice instability. We predict that the melting temperature Tm decreases strongly as a function of Te. Electronic excitation has a strong effect on the rate of crystallization from the melt. In particular, high Te results in very slow kinetics for growing crystal from the melt, due mainly to the fact that diamond becomes much less stable as Te increases. Finally, we explore annealing amorphous Si (a-Si) below Tm, and find that we cannot observe annealing of a-Si directly at high Te. We hypothesize that this is also due to the decreased stability of the diamond structure at high Te.
Giant magnetoresistance and table-like magnetocaloric effect in double perovskite oxide PrSrMnCoO6
Authors: Nath Mahato Rabindra , Sethupathi K. , Sankaranarayanan V. , Nirmala R. , Nigam A. K. , Malik S. K.
Published: April 2011

Magnetoresistance and magnetocaloric effect of a double perovskite oxide PrSrMnCoO6 (cubic, Fm3¯m) has been studied in fields up to 7 T. This compound is semiconductor-like and its electrical resistivity increases by 5 orders while going from 300 to 50 K. Giant magnetoresistance of ∼40% is observed at 200 K in 7 T field. PrSrMnCoO6 orders ferromagnetically at ∼150 K and shows a maximum magnetic entropy change of ∼4.6 J/kg/K for 5 T field change in the temperature range of 110–190 K. This nearly constant magnetocaloric effect over a broad temperature span is highly suitable for Ericsson-cycle magnetic refrigeration.
Effects of pulsed magnetic fields on the light scattering property of the freezing process of aqueous solutions
Authors: Iwasaka M. , Onishi M. , Kurita S. , Owada N.
Published: April 2011

The purpose of the study is to clarify the effect and mechanism of magnetic fields on freeze processes in aqueous solutions. In the present study, an ice crystal formation process in biological aqueous solutions under pulsed train magnetic fields (PMF) of up to 325 T/s at 6.5 mT was observed. The pulsed magnetic field generators were set in a freezer, which controlled the temperature between 10C and −30 °C. During ice formation in the aqueous solution, disk-like ice crystal domains appeared, and the PMF-exposure exhibited a vibration of floating objects in the induced electric field directions under the cooled condition when the pulsed train frequency was changed between 10 and 17 Hz. In the freezing process of the aqueous solution with NaCl, the scattered light transmission of the ion containing the aqueous solution increased in the early phase of freezing, and then began to decrease during the late phase when the ice coagulation proceeded. The PMF exposure enhanced the light-scattering increase and decrease in the early and late phases, respectively. The results suggested that a fine ice crystal, which strongly scattered the irradiated light, increased in number in the early phase of the supercooled state when the PMF was applied.
Fabrication and physical properties of double perovskite SrLaVMoO6 thin films
Authors: Matsushima H. , Gotoh H. , Miyawaki T. , Ueda K. , Asano H.
Published: April 2011

SrLaVMoO6 thin films have been grown on various substrates by magnetron sputtering in Ar+H2 mixture gas. High-quality c-axis oriented SrLaVMoO6 films have been obtained in the growth temperature of 630 °C and Ar + 5% H2 mixture gas. The SrLaVMoO6 films showed low resistive metallic behavior, which is comparable to bulk SrLaVMoO6. X-ray photoemission spectroscopy measurements indicate that the dominant valence state for Mo and V in the SrLaVMoO6 films is tetravalent (Mo4+) and trivalent state (V3+), respectively.
Epitaxial growth and thermal stability of Fe4N film on TiN buffered Si(001) substrate
Authors: Xiang H. , Shi F.-Y. , Rzchowski M. S. , Voyles P. M. , Chang Y. A.
Published: April 2011

Epitaxial Fe4N thin films were grown on TiN buffered Si(001) substrate by dc reactive sputtering deposition at different substrate temperatures. Fe4N films epitaxially grew on TiN within the substrate temperature range from 250 to 350 °C. Lower than 250 °C there will be some other FexN compounds formed and higher than 400 °C there will be only Fe left. Fe4N is metastable and the postannealing process in vacuum will decompose Fe4N film to Fe. However, introducing 30% N2 in the postannealing atmosphere can stabilize the Fe4N up to 350 °C in the (Ar,N2) gas mixture. The surface roughness of the epitaxial Fe4N films decreases with film thickness. There is in-plane biaxial magnetic anisotropy of epitaxial Fe4N(001) on Si(001) with the [100] easy direction.
Angular and energy distribution of Sn ion debris ejected from a laser-produced plasma source, for laser power densities in the range suitable for extreme ultraviolet lithography
Authors: O’Connor A. , Morris O. , Sokell E.
Published: April 2011

In this paper, experimental results are presented for the spatial and energy distributions of charge-discriminated Sn ions ejected from laser-produced plasmas. The plasmas were formed on solid, planar Sn targets, irradiated with a Nd:YAG laser. Ions were investigated using a calibrated electrostatic sector analyzer, scanning an energy-to-charge ratio range of 0.22 to 2.2 keV/e for emission angles between 20 and 80 degrees relative to target normal. Results were obtained for three laser power densities, in the region suitable for inducing significant extreme ultraviolet emission, of the order 1.5–8.1 × 1011 W/cm2. The fully differentiated data were found to be well characterized by Gaussian fits, which allowed trends in the emission profiles to be readily quantified. Ions of set energy and charge were observed to possess a preferential angle of emission, the superposition of which yields a physical basis for the total angular emission observed previously and in this work. The experimental results obtained have been related to physical processes within the plasma that influence the energy and angle of ejection of ions from laser produced plasmas.
Enhancement of airborne shock wave by laser-induced breakdown of liquid column in laser shock cleaning
Authors: Jang Deoksuk , Park Jin-Goo , Kim Dongsik
Published: April 2011

In laser shock cleaning (LSC), the shock wave is generated by laser-induced breakdown of the ambient gas. The shock wave intensity has thus been a factor limiting the performance of the LSC process. In this work, a novel method of amplifying a laser-induced plasma–generated shock wave by the breakdown of a liquid column is proposed and analyzed. When the laser beam is focused on a microscale liquid column, a shock wave having a significantly amplified intensity compared to that generated by air breakdown alone can be generated in air. Therefore, substantially amplified cleaning force can be obtained. The dynamics of a shock wave induced by a Q-switched Nd:YAG laser was analyzed by laser flash shadowgraphy. The peak pressure of the laser-induced shock wave was approximately two times greater than that of air breakdown at the same laser fluence. The proposed method of shock wave generation is expected to be useful in various applications of laser shock processing, including surface cleaning.
Thermally and field-driven spin-state transitions in (Pr1−yYy)0.7Ca0.3CoO3
Authors: Maryško M. , Jirák Z. , Knížek K. , Novák P. , Hejtmánek J. , Naito T. , Sasaki H. , Fujishiro H.
Published: April 2011

The first-order character of the transition from the low-to-intermediate spin state in the system (Pr1−yYy)0.7Ca0.3CoO3 (y = 0.075–0.15) has been verified by magnetization measurements. For y = 0.075, the transition manifests itself in χ(T) steps at temperatures depending on external fields. In this case, isothermal measurements show a field-driven transition exhibiting a field hysteresis. The entropy contribution is evaluated and discussed. Qualitative analysis based on a two-level model suggests that the observed influence of the magnetic field can be explained only by assuming the presence of exchange interactions.
Room temperature ferromagnetism in HfO2 films
Authors: Bharathi K. Kamala , Venkatesh S. , Prathiba G. , Kumar N. Harish , Ramana C. V.
Published: April 2011

HfO2 films were produced by sputter deposition in the substrate temperature (Ts) range of room temperature (RT)−300 °C and their structural, magnetic, and electrical properties were evaluated. The results indicate that the HfO2 films crystallize in the monoclinic structure and are oriented along the (−111) direction. Magnetization measurements (300–1.8 K) evidence their RT ferromagnetism. The effect of Ts is significant on the magnetic moment (M) and coercivity (Hc). M and Hc values enhanced with increasing Ts due to formation of oxygen vacancies. Increase in the temperature from 150 to 300 K decreases Hc without any transition, indicating that the Curie temperature of HfO2 films is higher than RT. Electrical measurements indicate that the HfO2 films are semiconducting.
Properties of molecular beam epitaxy grown Eux(transition metal)y films (transition metals: Mn, Cr)
Authors: Balin K. , Nowak A. , Gibaud A. , Szade J. , Celinski Z.
Published: April 2011

The electronic and crystallographic structures, as well as the magnetic properties, of Eux(transition metal)y (transition metals: Mn, Cr) thin films grown by molecular beam epitaxy were studied. Relative changes of the Eu/Mn and Eu/Cr ratios derived from the XPS lines, as well as x-ray reflectivity, indicate mixing of the Eu/Mn and Eu/Cr layers. Valency transitions from Eu2+ to Eu3+ were observed in both systems for most studied stoichiometries. A transition to a magnetically ordered phase was observed at 15 K, 40 K, and 62 K for selected films in the Eu–Mn system, and at 50 K for the film with a Eu/Cr ratio of 0.5.
Magnetoelectric memory using orthogonal magnetization states and magnetoelastic switching
Authors: Tiercelin Nicolas , Dusch Yannick , Preobrazhensky Vladimir , Pernod Philippe
Published: April 2011

We present here a concept of a memory cell called MELRAM based on a magnetic element with giant magnetostriction, embedded in a piezoelectric matrix. Two equilibrium orientations of magnetization are defined by combining uniaxial anisotropy together with a magnetic polarization in the hard axis direction. Using the piezoelectric matrix, an anisotropic stress is created onto the magnetic element when applying a voltage across electrodes. Thanks to the inverse magnetostrictive effect, the effective anisotropy of the magnetic element is controlled by the applied voltage and used to switch magnetization from one state to the other. Micromagnetic simulations show the effect of applied stress on magnetization and theoretical feasibility of the device. Retrieval of information can be nondestructively made by giant magnetoresistance reading. Details of the principle, simulations, and performance perspectives are discussed.
Two-dimensional soft output Viterbi algorithm with noise filter for patterned media storage
Authors: Kim Jinyoung , Lee Jaejin
Published: April 2011

We introduce a two-dimensional (2D) soft output Viterbi algorithm (SOVA) using two 1D SOVAs, which apply two noise filters corresponding to horizontal and vertical directions, respectively, for patterned media storage. Patterned media storage has 2D intersymbol interference (ISI), which includes ISI from neighboring symbols and intertrack interference from adjacent tracks, since there is a small space between adjacent tracks and neighborhood symbols. Noise filter replaces colored noise with white noise. As a result, the noise filter can reduce the noise power, so that performance can be improved. As shown in the simulation results, when there is no off-track, the 2D SOVA using a noise filter is approximately 0.4 dB better than not using a noise filter at a 10−6 bit error rate; when there is 20% off-track, it has about a 1 dB gain.
Plasma-based localized defect for switchable coupling applications
Authors: Varault Stefan , Gabard Benjamin , Sokoloff Jérôme , Bolioli Sylvain
Published: April 2011

We report in this paper experimental measurements in order to validate the concept of switchable electromagnetic band gap filters based on plasma capillaries in the microwave regime. The plasma tube is embedded inside the structure to create a bistable (plasma on or off) punctual defect. We first investigate two kinds of discharge tubes: Ar–Hg and pure Ne, which we then use to experimentally achieve plasma-based reconfigurable applications, namely, a two-port coupler and a two-port demultiplexer.
Raman analysis of three-dimensionally graded stress tensor components in sapphire
Authors: Zhu Wenliang , Pezzotti Giuseppe
Published: April 2011

An improved method of confocal/polarized Raman spectroscopy is proposed, which enables the determination of the full set of tensor components in three dimensionally graded stress fields in sapphire single-crystal. From the experimental side, the proposed method employs a simple back-scattered configuration for the optical microprobe and relies on the experimental knowledge of the matrix of piezospectroscopic (PS) coefficients of sapphire (i.e., the proportionality constants relating the frequency shifts of individual Raman bands to the magnitude of an uniaxial stress applied along different crystallographic directions). From the theoretical side, the complete set of stress tensor components were generally expressed as a function of the PS coefficients for any unknown multiaxial stress state by means of the Euler transformation matrix, leading to a system of linear equations; such equations link each stress component to the experimentally observed spectral shifts of different Raman bands. The proposed PS method does not require a direct knowledge of the secular equation, but local crystallographic orientations should be retrieved from polarized Raman intensities. With probe averaging effects being systematically removed by probe deconvolutive routines, the PS method is shown to correctly resolve multiaxial stress tensor fields with steep gradients in space.
Low temperature growth of FePt and CoPt films on MgO(111) substrate
Authors: Yuan Fu-Te , Sun A. C. , Mei Jui-Kuo , Liao W. M. , Hsu Jen-Hwa , Lee H. Y.
Published: April 2011

Equiatomic CoPt and FePt thin films grown on MgO(111) substrates at temperatures (Ta) from room temperature (RT) to 400 °C were studied. Distinct phase evolution was observed. In CoPt films, a metastable phase of L11 appears at Ta = 250 °C prior to the formation of thermodynamic equilibrium L10 phase; whereas no intermediate structure is found in the FePt films. Good epitaxial growth of CoPt films can be obtained at low Ta before ordering. However, in FePt films, high quality epitaxy appears after the occurrence of L10 ordering. Either L11 or L10 ordering induces magnetic hardening. Perpendicular magnetic anisotropy was obtained in the L11 films, yet the L10 sample exhibited isotropic magnetism. Corresponding evolution in magnetic domain structure was also reported.