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In this article, a 16-multilayer Co/Ni/Fe film was prepared by using a three-source magnetically filtered metal vapor vacuum arc deposition system. The microstructure evolution and the variation of magnetic properties of the film during a vacuum annealing process were monitored by Rutherford backscattering spectroscopy, x-ray diffraction, vibrating sample magnetometer, scanning atomic force microscopy, and magnetic force microscopy experiments. It was found that the saturation magnetization of the film was enhanced gradually by the interdiffusion and alloying effect within the multilayers caused by vacuum annealing. Meanwhile, however, the magnetic domain grew to a larger scale progressively, and the film became magnetically harder and harder.

In recent years, doped diamond-like carbon (DLC) coatings have been shown to solve some intrinsic application difficulties of DLC, esp. reducing internal stresses and improving thermal stability. Diamond-like nanocomposite (DLN), by incorporating an amorphous Si-O network into the DLC, is a special class of modified DLC coatings, which have many excellent properties and wide applications. In this paper, a diamond-like nanocomposite film was synthesized by an ion beam assisted deposition method in an acetylene atmosphere. The composition and microstructure of the DLN film were investigated by various spectroscopic analyses, including Fourier transform infrared absorption spectroscopy, Rutherford backscattering spectroscopy. Raman scattering spectroscopy, X-ray photoelectron spectroscopy, and ultraviolet-visible absorption spectroscopy.

Buried SiC layers were formed by dual-energy implantation of carbon into silicon at 40 and 65 keV to doses of 6 × 1017 and 1.2 × 1018 cm−2, respectively. Annealing was performed at temperatures from 600°C to 1200°C for various time intervals in nitrogen. The phase transformation characteristics in these SiC layers were studied using FTIR spectroscopy and a de-convolution scheme of the IR spectra into amorphous SiC and β-SiC components. The β-SiC fraction in the as-implanted samples was found to depend significantly on the order of the dual-energy implantation as a result of the IBIC effect. Further evolution of the relative amount of the various SiC phases upon annealing could well be described by the classical nucleation and growth theory using a two-dimensional growth model. The overall enthalpy of the transformation was determined to be 0.28 eV/atom.

Cobalt–silver granular thin films exhibiting giant magnetoresistance (GMR) effect were formed by Co implantation into Ag using a metal vapor vacuum arc (MEVVA) ion source. The magnetic field dependence and the temperature variation of the GMR effect and their relation with the processing conditions were studied and discussed in conjunction with results of Rutherford backscattering spectrometry, atomic force microscopy and magnetic force microscopy (MFM). For the best sample obtained in this study, the magnitude of the GMR effect measured at a magnetic field strength of 7.6 kOe increases from about 1% at room temperature to over 7% at 20 K. The coercive field H C in the perpendicular-to-film direction determined from GMR measurements showed an anomalous temperature variation that shows a maximum value at around 240 K and decreases with decreasing temperature from 240 to 20 K. The domain structures of the implanted granular films revealed by MFM images exhibit a very different feature compared with those of sputter deposited Co–Ag granular films.

Germanide formation and evolution in Co-implanted germanium have been studied by θ–2θ X-ray-diffraction (XRD), atomic force microscopy (AFM) and the Rutherford backscattering spectrometry (RBS). A metal vapor vacuum arc (MEVVA) ion source implanter operated at 60 kV was used to implant Co into Ge(1 0 0) wafers with doses ranging from 6 × 1014 to 6 × 1018 cm−2, and mean current density being either 15 or 210 μA cm−2. The sequence of phase formation was obtained by XRD. Dramatic cellular and columnar nanostructures were observed by AFM in the low and high mean current density samples, respectively. Information on the roughness was obtained. The degree of crystallinity and the thickness of the damaged layer were determined by RBS and ion channeling. The phase formation and evolution are discussed with respect to beam heating effect and the heat of formation.

Ion beam synthesis of by Co implantation with a metal vapour vacuum arc ion source has been performed and the effects of substrate temperature on precipitate coarsening and Co distribution in the as-implanted samples have been investigated. The microstructure changes were studied by transmission electron microscopy and the Co distribution shift towards the surface with increasing substrate temperature was observed by Rutherford backscattering spectrometry experiments. Direct measurements of the sputtering depth on masked implanted samples at various substrate temperatures showed that the sputtering yield decreases with increasing temperature. The Co distribution shift phenomenon was explained using a model incorporating both the temperature dependent sputtering yield effect and the precipitate coarsening effect. This model also provides a consistent picture to explain at least partially and qualitatively the observed opposite trends of Co distribution shift towards the surface or the substrate with increasing substrate temperature reported in the literature.

Nitrogen-containing tetrahedral amorphous carbon films (ta-C) have been prepared using a magnetic field filtered plasma stream deposition method. The plasma stream was first formed by sputtering of a graphite target in nitrogen-argon atmospheres. The partial pressure of nitrogen, , was in the range 0-7 Pa at total pressure of deposition Pa. The optical and electrical properties of samples were studied using x-ray photoelectron spectroscopy (XPS), Fourier transform infrared absorption spectroscopy (FTIR), UV-visible optical absorption spectroscopy and measurements of electrical conductivity in the temperature range 300-500 K. The incorporation of small amounts of nitrogen will result in an increase in electrical conductivity, a slight drop of the band gap and an increase in band-tail absorption. These suggest that incorporation of a small amount of nitrogen into ta-C films will induce graphitization of bonding. For samples deposited at Pa, nitrogenation of films is very pronounced. The actual nitrogen content in films in terms of atomic percentage can be as much as 47%. The films have a wide band gap of 4.05 eV and an extremely low electrical conductivity. These suggest that a carbon nitride film is formed. The configurations of N atoms in the ta-C network are identified and discussed.

at temperatures ranging from 600 to 1200 °C for 2 h. Rutherford backscattering spectrometry (RBS) analysis revealed carbon distribution and the formation of an SiC layer. Infrared spectroscopy (IR) exhibited a sharp absorption peak produced by the Si-C bond at 795 cm-1 with full width at half maximum (FWHM) of about 35 cm-1. A layer of crystalline SiC was formed after annealing the as-implanted sample at 1000 °C for 2 h. The influence of annealing temperature on the surface morphology and the dynamics of the crystallization procedure was studied by atomic force microscopy (AFM). A study of grain size and roughness revealed that the morphology of the SiC layer was largely dependent on annealing temperature, and the average grain size increased as the annealing temperature was raised. At about 900 °C, a layer of nanocrystalline SiC was formed on the sample surface, containing columnar grains with a FWHM of tens of nanometers and a height of less than ten nanometers.

We propose and demonstrate an in-line channel power monitor (ICPM) based on helium ion implanted silicon waveguides. The implanted waveguide can detect light at below-bandgap wavelengths (1440-1590 nm) which are normally not detectable by silicon. We study the enhanced photoresponse of helium ion implanted samples which were annealed at 200 degC, 300 degC, or 350 degC for different durations. Optical absorption and photodetector current measurements were performed for each sample. The ICPM can provide the same function as a waveguide tap coupler and a hybrid-integrated conventional photodiode

We have employed the IR photoelasticity (PE) method to study the stress distribution in Si substrates under various thin film structures. A few examples are given to demonstrate how information on the two dimensional stress distribution in the substrate under these thin film structures can be obtained from PE experiments. It is also demonstrated that the PE method is a promising technique for the study of edge effects on stress distribution in semiconductors under patterned thin film structures.

Tin-doped C60 thin films have been prepared by co-evaporation. Through controlling the temperature of the boat containing Sn, C60 thin films with different Sn content have been obtained. The electrical and defect properties of these Sn-doped C60 films have been studied using resistivity, Hall effect and electron spin resonance (ESR) measurements. Besides the ESR signal of g = 2.0024 normally observed for all the undoped C60 materials, a new signal was observed for all the doped C60 films. The g factor and peak-to-peak linewidth of the new signal are 2.0003 and 1.12 G, respectively. The spin density of the new signal increases with increasing Sn content. The temperature dependence of the electrical resistivity of these Sn-doped C60 films shows semiconducting behaviour in the temperature range from 20 to 420 K. The room temperature conductivity increases with increasing Sn content and the activation energy at room temperature decreases with increasing Sn content. Hall effect measurements indicated that the conduction type in these Sn-doped C60 thin films is n-type. Fourier transform infrared absorption measurements verified that Sn atoms have indeed been incorporated into these Sn-doped C60 films.

The objective of this study was to investigate the potential of an instrumental taste-sensing system to distinguish between shrimp processing by-products hydrolysates produced using different proteases and hydrolysis conditions, and the possible association of taste sensor outputs with human gustatory assessment, salt content, and bioactivity. Principal component analysis of taste sensor output data categorised samples according to the proteases used for hydrolysis. High umami sensor outputs were characteristic of bromelain- and Flavourzyme-produced hydrolysates, compared to low saltiness and high bitterness outputs of Alcalase-produced hydrolysates, and high saltiness and low umami outputs of Protamex-produced hydrolysates. Extensively hydrolysed samples showed higher sourness outputs. Saltiness sensor outputs were correlated with conductivity and sodium content, while umami sensor responses were related to gustatory sweetness, bitterness and umami, as well as angiotensin-I converting enzyme inhibitory activity. Further research should explore the dose dependence and sensitivity of each taste sensor to specific amino acids and peptides.

ObjectiveTo examine the opinions of stakeholders on strategies to improve dietary quality of Supplemental Nutrition Assistance Program (SNAP) participants.DesignParticipants answered a thirty-eight-item web-based survey assessing opinions and perceptions of SNAP and programme policy changes.SettingUSA.SubjectsSurvey of 522 individuals with stakeholder interest in SNAP, conducted in October through December 2011.ResultsThe top three barriers to improving dietary quality identified were: (i) unhealthy foods marketed in low-income communities; (ii) the high cost of healthy foods; and (iii) lifestyle challenges faced by low-income individuals. Many respondents (70 %) also disagreed that current SNAP benefit levels were adequate to maintain a healthy diet. Stakeholders believed that vouchers, coupons or monetary incentives for purchasing healthful foods might have the greatest potential for improving the diets of SNAP participants. Many respondents (78 %) agreed that sodas should not be eligible for purchases with SNAP benefits. More than half (55 %) believed retailers could easily implement such restrictions. A majority of respondents (58 %) agreed that stores should stock a minimum quantity of healthful foods in order to be certified as a SNAP retailer, and most respondents (83 %) believed that the US Department of Agriculture should collect data on the foods purchased with SNAP benefits.ConclusionsResults suggest that there is broad stakeholder support for policies that align SNAP purchase eligibility with national public health goals of reducing food insecurity, improving nutrition and preventing obesity.

Campaign fatigue was evident in a large hospital in Hong Kong when hand hygiene compliance remained just above 50% after 4 years of aggressive and varied promotional activities. A new innovative strategy was developed that directly involved the infection control link nurses both in formulating the strategy and in implementing the various proposed programs. The new strategy was successful in increasing hand hygiene compliance to 83%.

High dose Ge implantation into p-type Si wafers at 150 keV has been performed at doses of 3.6 × 1016, 6.7 × 1016 and 9.0 × 1016 cm−2. The Ge distribution and the crystal quality of the implanted layer before and after annealing at various temperatures have been studied by RBS and channeling experiments. It is found for the medium and high dose samples before annealing, more than 90% of the Ge atoms are interstitial sites and after annealing at 1000°C, more than 50% of the Ge atoms have become substitutional. The situation is better for the low dose sample where less than 70% of the Ge atoms are in interstitial sites before annealing and about 80% of them become substitutional after annealing at 1000°C. The ESR spectra of these samples are of Lorentzian shape with a g-value of about 2.007 and a spin density of about 6 × 1016 cm−3. The ESR signals of these samples have been inferred to be mainly due to Si-dangling bonds in the GeSi alloy layer and can be eliminated by annealing at 1000°C for 2 min. Electrical characterization of the GeSi layer by spreading resistance profiling technique shows that the implantation damage has been extanded deep into the substrate before annealing. After annealing at 1000°C, these defects are removed but the spreading resistance of the surface GeSi layer is found to remain higher than that of the substrate.

We have developed a modified separation-by-implantation-of-oxygen (SIMOX) process for fabricating relaxed silicon–germanium-on-insulator (SGOI) substrates without using thick graded SiGe buffer structures. Oxygen ions are implanted into a pseudomorphically grown 115 nm Si0.86Ge0.14 layer, with the implant peak located slightly below the heterostructure interface. Following two annealing processes (∼800+1350 °C) instead of conventional one-step annealing (∼1350 °C) in traditional SIMOX, a buried silicon dioxide layer is created near the original SiGe/Si interface, resulting in a fully relaxed SGOI structure. Our results show that an annealing step at a moderate temperature (∼800 °C) leads to less Ge loss.

The properties of natural actomyosin (NAM) containing 2% or 8% fish protein hydrolysate (FPH-2, FPH-8) or 8% sucrose-sorbitol blend (SuSo) were compared to control NAM before and after freeze-thaw treatment. Surface hydrophobicity of control and FPH-2 increased after freeze-thaw treatment, while that of FPH-8 did not change, which may be related to greater thermostability of actin and myosin in FPH-8 as observed by differential scanning calorimetry. The cooked gel of freeze-thawed control had 39% expressible moisture after an 8.5% cook loss, whereas gels of freeze-thawed SuSo, FPH-2 and FPH-8 had significantly lower expressible moisture (15-22%) and no cook loss. Gels of freeze-thawed FPH-2 and FPH-8 were similar to unfrozen control gel in hardness, cohesiveness and gumminess. This study demonstrates that FPH effectively stabilised NAM protein structure and function during freeze-thaw treatment.

The effects of production factors (protease used, percent enzyme, hydrolysis time, and water-to-substrate ratio) on the antioxidant activity of hydrolysates produced from shrimp processing byproducts (SPB) were assessed using Taguchi's L16 (4(5)) fractional factorial design. SPB hydrolysates showed excellent ABTS radical scavenging activity, metal ion chelating capacity, and inhibition of lipid peroxidation, but weak DPPH radical scavenging activity and ferric ion reducing antioxidant power. The protease used significantly influenced antioxidant activities while hydrolysis time and percent enzyme affected radical scavenging activities and inhibition of lipid peroxidation, respectively. Differences in the lipid and amino acid contents observed between SPB collected early and late in the egg-bearing period may have contributed to the slight variance in antioxidant activities displayed by their hydrolysates. Nevertheless, SPB hydrolysates produced using Alcalase or Protamex had high antioxidant activity regardless of production factors and egg-bearing period.

Nanocomposite (Pr0.17Co0.83)69C31 thin films were prepared by pulsed filtered vacuum arc deposition. Rapid thermal annealing was performed at various temperatures in argon. The variations of the structure and magnetic properties of these films with various annealing temperatures were studied systematically. The sample annealed at 700 °C for 1 min shows a large coercivity of 5.2 kOe and a small grain size of 7.8 nm. The overall small negative ΔM of this film indicates that virtually all the Pr0.17Co0.83 grains are isolated single domain particles with only weak dipolar interactions among them. These results indicate that (Pr0.17Co0.83)69C31 nanocomposite thin films would be a promising candidate for high-density magnetic recording medium applications.

Nickel disilicide (NiSi2) layers were synthesized by nickel ion implantation into silicon substrates using a metal vapor vacuum-arc ion source. The electrical transport properties were studied before and after annealing using sheet resistivity and Hall effect measurements from 30 to 400 K, and the results showed surprising features very different from those generally reported NiSi2 layers. The temperature dependence of sheet resistivity Rs(T) and Hall mobility μH(T) in the as-implanted samples showed peculiar peak and valley features varying from sample to sample, depending on the preparation conditions. However, after annealing, the differences between samples seemed to have diminished in that they all showed similar shapes in both the Rs(T) and the μH(T) curves. A two-band model was proposed to explain the observed electrical transport properties.

The antioxidative properties of Pacific hake hydrolysates and their peptidic fractions varying in molecular size were assessed. Hydrolysates produced by different proteases (Alcalase, bromelain, Flavourzyme, Protamex, Protease A"Amano"2, Protease N"Amano"K, Protin SD NY10, Umamizyme-K, Validase BNP-L, Validase FPexo) generally possessed good metal ion chelating (33-73% at 3mg/ml), DPPH radical scavenging (18-30% at 1mg/ml), ferric ion reducing power (abs700nm 0.36-0.86 at 3 mg/ml) and ABTS radical scavenging (47-85% at 0.067 mg/ml) activity, as well as a good capability to suppress lipid peroxidation in a linoleic acid model system. Peptide size (

Background The hypertrophic myocardium, myocardial fiber disarray, and endocardial fibroelastosis in pulmonary atresia and intact ventricular septum (PAIVS) may provide anatomic substrates for restrictive filling of the right ventricle. Hypothesis Restrictive right ventricle (RV) physiology is related to RV fibrosis and exercise capacity in patients after biventricular repair of PAIVS. Methods A total of 27 patients, age 16.5 ± 5.6 years, were recruited after biventricular repair of PAIVS. Restrictive RV physiology was defined by the presence of antegrade diastolic pulmonary flow and RV fibrosis assessed by late gadolinium enhancement (LGE) cardiac magnetic resonance. Their RV function was compared with that of 27 healthy controls and related to RV LGE score and exercise capacity. Results Compared with controls, PAIVS patients had lower tricuspid annular systolic and early diastolic velocities, RV global longitudinal systolic strain, systolic strain rate, and early and late diastolic strain rates (all P < 0.05). A total of 22 (81%, 95% confidence interval: 62%–94%) PAIVS patients demonstrated restrictive RV physiology. Compared to those without restrictive RV physiology (n = 5), these 22 patients had lower RV global systolic strain, lower RV systolic and early diastolic strain rates, higher RV LGE score, and a greater percent of predicted maximum oxygen consumption (all P < 0.05). Conclusion Restrictive RV physiology reflects RV diastolic dysfunction and is associated with more severe RV fibrosis but better exercise capacity in patients after biventricular repair of PAIVS. Copyright © 2010 Wiley Periodicals, Inc.

High dose fluorine implantation into silicon wafers at 90 keV has been performed to produce a surface layer of fluorinated amorphous silicon. The lateral photoeffect in these samples and their dependence on the flourine dose and thermal annealing conditions have been studied. For samples with appropriate thermal annealing, a lateral photovoltage as high as 300 mV has been observed. It is also found that splitting has been induced in the ESR spectra for the fluorine implanted samples. The spectra can be resolved into two resonances with g-factors of 2.0062 and 2.0030, respectively. The resonance with the larger g-factor is attributed to dangling bonds due to implantation damage. The resonance with the smaller g-factor is associated with the presence of fluorine atoms as its magnitude increases with fluorine dose. After annealing, the magnitude of the resonance of the larger g-factor drops much faster with increasing annealing, the magnitude of the resonance of the larger g-factor drops atoms as dangling bond terminators. Optical reflectance experiments and SEM observations reveal that the fluorinated amorphous silicon layer has not been recrystallized even after annealing at 600°C for two hours.

The potential for producing antihypertensive peptides from oat proteins through enzymatic hydrolysis was assessed in silico and confirmed in vitro. Thermolysin (EC 3.4.24.27) was predicted using BIOPEP database as the enzyme that would theoretically produce the most angiotensin I converting enzyme (ACE) inhibitory peptides from oat. Experimental evidence confirmed that strong ACE-inhibitory activity was produced under various hydrolysis conditions. Hydrolysates produced under high enzyme-to-substrate ratio (3%) short time (20 min) (HEST) and low enzyme-to-substrate ratio (0.1%) long time (120 min) (LELT) conditions had IC(50) values of 30 and 50 microg/mL, respectively. After simulated gastrointestinal digestion, the IC(50) of the HEST hydrolysate was 35 microg/mL whereas the IC(50) of the LELT hydrolysate was higher at 85 microg/mL. Ultrafiltration revealed that potent ACE-inhibitory peptides had molecular weights below 3 kDa. This study demonstrates the usefulness of in silico analysis to select enzymes for hydrolysis of proteins not previously examined as sources of bioactive peptides.

Polyacrylamide hydrogel (PAAG) has been used as an injectable filler for soft tissue augmentation for more than a decade. In recent years, PAAG has been advocated as a safe soft tissue filler for facial augmentation. However, the complications associated with PAAG injection in facial augmentation have not been widely covered in the literature. We present two cases of severe complications associated with PAAG injection in facial augmentation, including bony erosion and facial ulcer. Further studies are required to support the safety of PAAG in facial injection.

Purpose Acute appendicitis is the most common emergency presenting to pediatric surgeons. With proper history and thorough physical examination, the diagnosis of the condition clinically should approach 90%. With the increasing ease of performing radiologic investigations because of technological advances, more ultrasound and computed tomography (CT) are used to help diagnosing appendicitis. The aim of this study is to review the trend of diagnosing appendicitis in a single center and discuss the implications. Methods A retrospective analysis was carried out for all patients who were admitted with acute appendicitis between 1997 and 2007. The methods of diagnosis were divided into 3 groups as follows: clinical, ultrasound, and CT. The demographics and operative findings were noted. Statistical analysis was done using Fisher's Exact test and paired t test when appropriate. A value of P Results During this period, a total of 254 patients (167 boys and 87 girls) were admitted with appendicitis. The average age at presentation was 12 years, and the mean duration of symptoms before presentation was 2 days. For 11 years, there was an initial rise of the use of ultrasound (10% in 1997 to a peak of 60% in 2005). This percentage decreased with a corresponding rise of the use of CT scan (0% in 1997 to 35% in 2007). There was no correlation found between the use of adjunct investigations and the severity of appendicitis found at operation, suggesting an overreliance of CT. Conclusion It appears that there is an increasing trend in using radiologic investigations for the diagnosis of appendicitis for the past 11 years. With the association of cancer in later life and early radiation exposure well documented, it would be advisable to avoid the use of CT if possible.

This study aimed to test the hypothesis that right ventricular (RV) volume overload may result in left ventricular (LV) systolic dysfunction through induction of LV systolic dyssynchrony after tetralogy of Fallot (TOF) repair. Sixty patients with TOF repair were studied at 14.3 +/- 7.2 years after TOF repair. Real-time 3-dimensional echocardiographic data sets were acquired for measurement of LV and RV volumes and derivation of ejection fractions and pulmonary regurgitant volume. The LV systolic dyssynchrony index (SDI) was derived from the dispersion of time to minimum regional volume using a 16-segment model. The results were compared with those of 29 healthy controls. LV SDI was significantly higher in patients than controls (7.4% +/- 2.0% vs 3.0% +/- 0.9%, p0.001). The prevalence of LV mechanical dyssynchrony (SDI4.7%) in patients was 93% (95% confidence interval 87% to 100%). The time to minimum regional volume was significantly longer in all of the 6 basal segments and the midposterior segment (all p0.05) in patients than controls. Multivariate analysis identified RV end-diastolic volume (beta = 0.58, p0.001), LV ejection fraction (beta = -0.38, p0.001), and LV end-diastolic volume (beta = 0.26, p = 0.002) as significant correlates of LV SDI. In conclusion, in patients after TOF repair, RV volume overload has a negative effect on LV systolic function through induction of global LV mechanical dyssynchrony.

Background: Persistent arterial dysfunction in patients with a history of Kawasaki disease (KD) and an integral role of oxidative stress in the development of cardiovascular disease are increasingly recognized. We sought to test the hypothesis that oxidative stress is increased in KD patients and related to carotid atherosclerotic changes and stiffness. Methods: We compared the serum levels of oxidative stress biomarkers, carotid intima-media thickness (IMT), and carotid stiffness index among KD patients with coronary aneurysms (n = 32), those without coronary complications (n = 19), and controls (n = 32). Results: Compared with controls, patients with coronary aneurysms had significantly higher serum levels of malonaldehyde (2.62 ± 0.12 μM vs 2.22 ± 0.07 μM, p = 0.014) and hydroperoxides (26.50 ± 1.13 μM vs 22.50 ± 0.62 μM, p = 0.008). A linear trend of the magnitude of oxidative stress in relation to inflammatory damage was observed for malonaldehyde (p = 0.018) and hydroperoxides (p = 0.014) levels. Serum malonaldehyde and hydroperoxide levels correlated positively with carotid IMT (p < 0.001 and p = 0.034, respectively) and stiffness index (p = 0.001 and p = 0.021, respectively). Multiple linear regression analysis identified serum malonaldehyde level as a significant determinant of carotid IMT (β = 0.31, p = 0.006) and stiffness (β = 0.27, p = 0.008). Conclusion: Our findings suggestoxidative stress is increased in KD patients with coronary aneurysms and is associated with carotid intima-media thickening and stiffening. © 2008 Cheung et al; licensee BioMed Central Ltd., published_or_final_version

To determine the usefulness of new two-dimensional strain indices, based on speckle tracking imaging, for assessment of systemic right ventricular (RV) function after an atrial switch operation for transposition of the great arteries.Cross-sectional study.Tertiary paediatric cardiac centre.26 patients, mean (SD) age 21.0 (3.6) years at 19.9 (3.2) years after an atrial switch operation, and 27 age-matched controls were studied. Two-dimensional imaging at the four-chamber view was obtained with tracing of the entire RV endocardial border. The RV global longitudinal strain (GLS) and GLS rate were derived using automated software (EchoPAC, GE Medical) and correlated with tissue Doppler-derived RV isovolumic acceleration (IVA), and, in the patient cohort, with cardiac magnetic resonance-derived RV ejection fraction.Intra- and interobserver variability for measurement of GLS, as determined from the mean (SD) of differences in two consecutive results from 20 studies, were 0.06 (1.39)% and 0.24 (1.77)%, respectively. Compared with controls, patients had lower RV GLS (17.1 (1.9)% vs 26.3 (2.9)%, p0.001), a reduced GLS rate (0.78 (0.11)/s vs 1.33 (0.23)/s, p0.001), lower RV IVA (1.10 (0.36) m/s(2) vs 1.56 (0.53) m/s(2), p0.001) and increased RV myocardial performance index (0.52 (0.09) vs 0.38 (0.09), p0.001). Both RV GLS and GLS rate correlated positively with RV IVA (r = 0.43, p = 0.001 and r = 0.46, p0.001, respectively), and negatively with RV myocardial performance index (r = -0.65, p0.001 and r = -0.57, p0.001, respectively). In patients, the GLS rate correlated positively with RV ejection fraction (r = 0.62, p = 0.001).Two-dimensional RV GLS and GLS rate are new, potentially useful indices for assessment of systemic RV function.

The sulfur compound and dietary supplement S-adenosylmethionine (SAM) has been reported to have cytoprotective and antioxidant properties. However, the underlying mechanisms remain unresolved. The present study investigates the effect of SAM on the expression of the antioxidant stress proteins heme oxygenase-1 (HO-1) and ferritin in endothelial cells. Induction of the HO-1/ferritin-system leads to protection of tissues against several inflammatory stimuli. SAM increased the protein and mRNA levels of HO-1 in cultured endothelial cells. Induction of HO-1 gene expression was associated with elevated ferritin protein levels and regulated at the transcriptional level via increased promoter activity. HO-1 upregulation by SAM was causally related to a decrease in NADPH-mediated production of oxygen radicals. Our results demonstrate that the HO-1/ferritin-system is a novel target of the antioxidant compound SAM.

Understanding the transport process and the factors that control the influx/efflux of antibiotics between plasma and middle ear fluid is essential in optimizing the antimicrobial efficacy in the treatment of acute otitis media. In this study, an experimental chinchilla model with the application of a microdialysis technique was utilized to evaluate amoxicillin middle ear distribution kinetics. Amoxicillin solutions at various doses were instilled into the middle ear with a simultaneous intravenous bolus dose. Unbound amoxicillin levels were monitored by microdialysis in both ears. Serial phlebotomy provided samples for the measurement of unbound amoxicillin concentration in plasma ultrafiltrates. In infected chinchillas, discrete middle ear fluid samples were plated and cultured to characterize Streptococcus pneumoniae growth-kill kinetics. Noncompartmental analysis was used to estimate distributional and elimination clearances assuming linear pharmacokinetics. A nonlinear Michaelis-Menten equation was also used to determine the efflux clearance (from middle ear fluid to plasma) in a mammillary compartment model. No difference was observed in amoxicillin pharmacokinetics between control and infected chinchillas. Influx clearance was (4.6 ± 2.4) × 10 −3 ml/min-kg and significantly lower than the efflux clearance estimated as (19.2 ± 9.7) × 10 −3 ml/min-kg ( P < 0.002). Nonlinear kinetics was observed in the locally dosed ear. The microdialysis procedure did not interfere with the bacterial growth-kill profile, thereby enabling pharmacokinetic and pharmacodynamic evaluation concurrently. In conclusion, the results suggested that the distribution equilibrium of amoxicillin in the middle ear favors efflux to plasma over influx. An active transport mechanism across middle ear mucosal epithelium may be involved in amoxicillin distribution.

Many decisions in drug development and medical practice are based on measuring blood concentrations of endogenous and exogenous molecules. Yet most biochemical and pharmacological events take place in the tissues. Also, most drugs with few notable exceptions exert their effects not within the bloodstream, but in defined target tissues into which drugs have to distribute from the central compartment. Assessing tissue drug chemistry has, thus, for long been viewed as a more rational way to provide clinically meaningful data rather than gaining information from blood samples. More specifically, it is often the extracellular (interstitial) tissue space that is most closely related to the site of action (biophase) of the drug. Currently microdialysis (mu D) is the only tool available that explicitly provides data on the extracellular space. Although mu D as a preclinical and clinical tool has been available for two decades, there is still uncertainty about the use of mu D in drug research and development, both from a methodological and a regulatory point of view. In an attempt to reduce this uncertainty and to provide an overview of the principles and applications of mu D in preclinical and clinical settings, an AAPS-FDA workshop took place in November 2005 in Nashville, TN, USA. Stakeholders from academia, industry and regulatory agencies presented their views on mu D as a tool in drug research and development.

AAPS-FDA workshop white paper : Microdialysis principles, application, and regulatory perspectives report from the joint AAPS-FDA workshop, November 4-5, 2005, Nashville, TN

Hand hygiene has been shown to be effective in significantly reducing hospital acquired infections for many years. However it is difficult to maintain and enhance compliance with hand hygiene guidelines. In Hong Kong, we previously reported a strategy to counter campaign fatigue from 50%-55% in 2009-11 to 83% in 2012. Here we report a creative activity that we used to sustain and enhance hand hygiene compliance. In May 2014 we broke the first Guinness World Record for a Hand Sanitizing Relay. A total of 277 participants performed hand hygiene before two official and approved witnesses. Following this team-directed strategy, an increase in hand hygiene compliance was identified in June 2014 in two clinical areas with previously poor compliance. The longer term impact of this strategy remains to be determined. More broadly, further research is urgently needed on meeting the challenge of campaign fatigue, and maintaining and enhancing compliance with hand hygiene guidelines.

A remarkably low turn-on field of about 1 V/μm has been observed in electron field emission from planar SiC/Si heterostructures formed by high dose C implantation into Si using a metal vapor vacuum arc ion source. An implant energy of 35 keV was used to a dose of 1.0×1018 ions/cm2 with subsequent annealing in nitrogen at 1200 °C for 2 h. X-ray photoelectron spectroscopy showed that a thin surface stoichiometric SiC layer, with a thickness of about 150 nm, had been formed. Atomic force microscopy showed that there are densely distributed small protrusions formed on the surface. The formation of a thin surface stoichiometric SiC layer and the formation of densely distributed small protrusions on the surface are believed to be the two factors responsible for the efficient electron field emission.

In cases of slow or limited penetration of an antibiotic to the site of infection such as in acute otitis media (the middle ear), plasma levels of the agent may not reflect the concentrations that are relevant in determining clinical outcome. There is a need for a model that allows prediction of the time-course of unbound, pharmacologically active drug levels in middle ear fluid (MEF). This article introduces microdialysis as a sampling tool to measure unbound antibiotic concentrations in the MEF of the chinchilla, and briefly summarizes the results of studies of MEF penetration of a cephalosporin, a macrolide, and a ketolide antibiotic using this technique. The general concurrence of preliminary results of the chinchilla studies with clinical findings suggests that the chinchilla microdialysis model may be useful in predicting efficacy in patients.

This chapter focuses on the recent advances and applications of microdialysis in pharmacokinetic studies. The first section addresses the technical and theoretical issues regarding microdialysis experiments with an emphasis on obtaining pharmacokinetic data. The principles and methodologies for microdialysis probe calibration are examined. Various setups for microdialysis sampling and subsequent data analysis are also illustrated. The second section includes research articles since the year 2000, chosen from an extensive literature review to report and discuss the utilization and implications of microdialysis sampling in pharmacokinetics. These articles are discussed in three subsections dealing with the kinetics of drug delivery to specific targets, the kinetics of drug transport and metabolism, and the use of microdialysis to study the effects of pathophysiology or surgical intervention on pharmacokinetics. A concluding section briefly underscores the critical need to characterize microdialysis recovery in pharmacokinetic investigations.

For conditions such as acute otitis media, in which antibiotic penetration into middle ear fluid (MEF) may be slow or limited, antibiotic plasma levels may not reflect the concentrations at the site of infection that are relevant to clinical outcome. In such cases, a model is needed that will enable prediction of the time course of unbound, pharmacologically active antibiotic levels in MEF. We describe the use of microdialysis as a sampling tool for measurement of unbound antibiotic concentrations in the MEF of the awake, freely moving chinchilla. Results of studies of MEF penetration of the beta-lactam antibiotic, cefdinir, with use of this technique are also described. Preliminary results of studies of the penetration of antibiotics into MEF of the chinchilla appear consistent with clinical findings and suggest that the chinchilla microdialysis model may prove to be a useful tool for predicting antibiotic efficacy in patients.

A 15-year-old boy with inverted duplication of chromosome 15 was admitted for acute onset of irritability, increasing sleepiness, and worsening of seizures. He had been on valproate and other anticonvulsants. However, he was found to have hyperammonemia within 2 weeks after the addition of low-dose topiramate to valproate. He recovered within 7 days after discontinuation of valproate. Topiramate was tailed off. The reintroduction of valproate monotherapy caused hyperammonemia again without clinical features of encephalopathy. He also developed anticonvulsant hypersensitivity syndrome following the use of phenytoin. We propose the term topiramate-valproate—induced hyperammonemic encephalopathy syndrome to include the following features: excessive sleepiness or somnolence, aggravation of seizures, hyperammonemia, and absence of triphasic waves on electroencephalography in any individual on simultaneous topiramate-valproate therapy. The ammonia level ranged from 1.5 to 2 times normal. The serum valproate level might be within the therapeutic range. The possible mechanism is topiramate-induced aggravation of all the known complications of valproate monotherapy. This condition is reversible with cessation of either valproate or topiramate. ( J Child Neurol 2004;19:157—160).

Semiconducting FeSi 2 has attracted considerable amount of research interest in the past decade for its potential applications as a silicon-based light emitting material. In this work, FeSi 2 precipitates were formed in Si by iron implantation into silicon using a metal vapor vacuum arc ion source. The structures and light emitting properties of these ion-beam-synthesized FeSi 2 precipitates were studied in details using various characterization techniques, including transmission electron microscopy (TEM) and photoluminescence measurements. It was found that the implantation temperature played an important role on the dislocation loop formation and hence the FeSi 2 phase formation during the subsequent thermal annealing. Photoluminescence (PL) spectra were measured as a function of temperature from 80 to 300 K. Combining the TEM and PL results, the origins of the PL could be distinguished to be either from the defect-related emission of Si or from the FeSi 2 precipitates. The FeSi 2 precipitates were found to be highly-strained or relaxed depending on the implantation and annealing conditions. The band gap energy of the relaxed samples was determined to be about 11 meV higher than that of the highly strained samples. Simple metal-oxide-semiconductor (MOS) diode structures were fabricated to study the electroluminescence (EL) properties from this FeSi 2 /Si system. Preliminary results showed that clear EL signals were obtained even at room temperature for samples prepared at appropriate conditions. There are significant differences between the EL and PL spectra and the mechanisms of the EL emission has yet to be further investigated.

We have prepared FeSi2 precipitates of nanometer size in Si by ion implantation using a metal vapor vacuum arc (MEVVA) ion source and studied their photoluminescence properties. Broad photoluminescence (PL) spectra at around 1550 nm were observed for all samples attributed to emission from the FeSi2 precipitates. It was found that all the PL spectra can be decomposed into two peaks, a main peak at near 1530 nm and a satellite peak at 1607 nm. Samples with a furnace annealing (FA) step at a lower temperature of 850°C are found to have a main peak position at a longer wavelength close to 1540 nm. For samples with a FA step at higher temperatures, the main peak position shifts to shorter wavelengths of near 1525 nm. In addition, we have also prepared MOS structures with implanted FeSi2 precipitates incorporated in the structures and measured their EL properties. The EL properties from these FeSi2-Si MOS structures after various thermal treatments were measured as a function of temperature from 80 to 300 K. Our preliminary results show that clear EL signals are obtained even at room temperature under appropriate processing conditions.

We study the infrared photoresponse of silicon waveguides which were implanted with helium ions. The observed enhancement in responsivity at 1.55 mum wavelength was sufficient for use in in-line channel power monitoring applications

Diamond-like-carbon (DLC) films have an amorphous structure comprising a sophistical carbon matrix and have attracted a great deal of scientific interest. Metal-doped DLC (Me-DLC) can possess superior properties as metal nanoclusters or nanocrystalline metallic carbides can be embedded in the carbon network. Therefore, Me-DLC exhibits good adhesion to the substrate, high hardness, low friction coefficient and high magnitude of conductivity. In this work, a metal cathodic vacuum arc and acetylene dual plasma are synchronized to produce Me-DLC. We systematically fabricate the Me-DLC films by varying the acetylene flow rate and substrate bias voltage. Our results acquired by Rutherford backscattering spectrometry (RBS) show that the film thickness and metal content can be controlled by the process windows. Four point probe measurements illustrate a decrease in the resistivity with increasing metal content whereas x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD) results show the formation of carbide phases in the carbon matrix. To evaluate the thermal stability of the thin film, both undoped DLC and Me-DLC films are annealed at a series of temperature in argon ambient. Raman scattering results reveal that the Me-DLC films can tolerate a high annealing temperature without serious graphitization. It is believed that metals incorporation retards the restructuring of the carbon matrix during the annealing processes.