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We investigated the opto-electrical and electromigration properties of near ultraviolet light emitting diodes (UV-LEDs) fabricated with Ag–Pd–Cu (APC) and Ag only reflectors. It was shown that unlike Ag only sample, the APC sample revealed a smooth surface with hillocks when annealed at 600 °C. The 600 °C-annealed APC sample gave a reflectance of 84.2% at 400 nm, whereas the Ag sample had 69.0%. Both the samples exhibited ohmic behavior when annealed. The specific contact resistivity of the Ag and APC contacts annealed at 500 °C were estimated to be 2.59 × 10−4 and 1.85 × 10−4 Ωcm2, respectively. The X-ray photoemission spectroscopy Ga 2p core level results showed that for the annealed APC sample, the Ga 2p core level was shifted towards the lower binding-energies by 0.67 eV as compared to that of the as-deposited sample. Both UV-LEDs with the 500 °C-annealed Ag and APC reflectors gave the same forward voltage of 3.23 V at 20 mA. The UV-LED with the annealed APC reflector yielded 9.07% higher output at 100 mA than that with the annealed Ag reflector. The APC sample exhibited a longer median-time-to-failure (MTF) by a factor of 1.4 than the Ag sample. The activation energy for the electromigration of these samples was measured to be 0.58–0.7 eV. Electron back scatter diffraction (EBSD) and inverse pole figure (IPF) images revealed that the Ag sample was more -textured than the APC sample. Based on the scanning electron microscopy, EBSD and IPF results, the better thermal and electromigration properties of the APC sample are described and discussed.

We report on the formation of high barrier-height and transparent Ag/ITO Schottky contacts on n-GaN (nd = 5 × 1018 cm−3) for optoelectronic and transparent electronic devices. Calculations using the thermionic emission model-based current-voltage characteristics of the samples annealed at various temperatures showed small Schottky barrier heights (SBHs) of 0.31–0.37 eV and ideality factors of 1.84–2.19. Conventional activation energy plot showed greatly smaller Richardson constant than the theoretical value. To understand such abnormality, the modified Richardson plot, a model of lateral SBH variation with Gaussian distribution, and capacitance-voltage method were used, where their SBHs were estimated to be in the range 0.74–0.93 eV. Together with the temperature-dependent SBHs and ideality factors, these results imply that SBH behavior could be explained in terms of barrier inhomogeneity at the interfaces. The Ag/ITO samples annealed at 500 °C transmitted 80.9% at 560 nm. The X-ray photoemission spectroscopy (XPS) Ga 2p core level spectra from the interfaces of the samples shifted toward either higher or lower energies. Scanning transmission electron microscopy (STEM)-energy dispersive X-ray spectroscopy mapping results revealed the outdiffusion of Ga atoms from n-GaN when annealed at 500 °C. Based on the electrical, XPS and STEM results, the annealing temperature dependence of the SBHs is described and discussed.

We report the development of high-barrier-height and transparent Ti/ITO Schottky contacts on p-GaN for optoelectronic and transparent electronic devices. The Schottky barrier heights (SBHs) and ideality factors estimated using the current–voltage characteristics were in the ranges of 0.36–0.39 eV and 1.74–2.07, respectively, depending on the annealing temperature. However, the barrier inhomogeneity and modified Richardson plot methods yielded much larger SBHs in the range of 0.82–1.18 eV. At 560 nm, the transmittance of the Ti/ITO samples was in the range of 47.4–89.9%. The Ga 2p core levels obtained from the X-ray photoemission spectroscopy (XPS) of the interface regions of the ITO/Ti/GaN samples shifted toward higher or lower energies, depending on the annealing temperature. The normalized N/Ga atomic ratio showed that N and Ga vacancies were formed at the p-GaN surface region at 300 and 500 °C, respectively. The XPS Ti 2p, N 1s, and O 1s core level results showed the formation of interfacial TiN and TiO2 phases at 300 and 500 °C, respectively. The elemental mapping results obtained using scanning transmission electron microscopy (STEM) demonstrated the outdiffusion of Ga atoms in the sample annealed at 500 °C. On the basis of XPS and STEM results, the dependence of the SBHs on the annealing temperature is described and discussed.

We investigated the effect of the conducting substrate on the performance of GaAs-based VCSELs, where the substrates were 230 μm-GaAs (reference), 10 μm-GaAs/metal, and 0.5 μm-GaAs/metal. The VCSELs with the 10 μm- and 0.5 μm thick GaAs/metal-substrates produced higher light output power than the reference. For example, the thin GaAs/metal substrate samples showed 16.3%–16.7% higher light output power at 3.0 A than the reference. It was shown that the thin GaAs samples produced 12.2%–14.0% higher power conversion efficiency at 3.0 A than the reference. At a high current region, the metal-substrate samples yielded lower junction temperature than the reference, namely, the thin GaAs samples gave 42 °C–47.4 °C lower junction temperature at 2.0 A than the reference. Further, the thin GaAs samples revealed better light output degradation characteristics than the reference. For instance, the light output of the reference was degraded by 30.2% at 85 °C, whereas the thin GaAs samples were degraded by 20.1%–20.5%. Near-field images and emission profiles demonstrated that the metal-substrate samples suffered from no damage incurred during the VCSEL fabrication process.

To examine the associations of various parameters of obesity including adiposity with intraocular pressure (IOP) using nationally representative data of South Korean adults.This cross-sectional study analyzed the data from the 2008-2010 Korea National Health and Nutrition Examination Survey. A total of 15,271 subjects (6600 men and 8671 women) participated. Body mass index (BMI), waist circumference (WC), total body fat mass, and total and regional body fat percentage were measured as parameters of obesity.IOP showed positive linear associations with BMI, WC, total fat mass, and total and regional body fat percentages in men, and with BMI, WC, total fat mass, and trunk fat percentage in women after adjusting for confounding variables. Men with higher BMI, WC, total fat mass, and total and regional body fat percentages exhibited increasing trends in odd ratios for having IOP ≥ 18 mmHg after adjusting for all confounding factors (p for trend0.001 for BMI and total fat mass; p for trend = 0.038 for WC; 0.003 for total body fat percentage; 0.002 for trunk fat percentage; 0.004 for leg fat percentage). However, only BMI showed a significantly increasing trend in the risk of IOP ≥18 mmHg in women.In addition to BMI, WC and total fat mass, total and regional body fat percentage in men and trunk fat percentage in women are positively associated with IOP. Increased BMI, WC, and total and regional body fat are positively associated with a risk of higher IOP (IOP ≥18 mmHg), especially in Korean men.

GaN-based ultraviolet UVLEDs have attracted a great deal of interest because of their applications in water and air purification and solid-state lighting. These applications have stimulated the technological development of high-efficiency UVLEDs. On the one hand, UVLEDs exhibit relatively lower external quantum efficiencies (EQEs) than visible LEDs. In particular, high-power UVLEDs should have high light extraction and heat dissipation efficiencies. For the flip-chip (FC) LEDs, the fabrication of high-performance p-type reflector with low contact resistance and high reflectivity is reqyired. Silver (Ag) is a commonly adopted p-type reflector for near UV LEDs but suffers from thermal instability, namely, agglomerated when annealed in air above 300 °C. In addition, electromigration (EM) is one of the major failure mechanisms of electronic interconnect under high current density (> ~105 A/cm2) stressing in microelectronics devices. In this talk, we investigated the opto-electrical properties, and electromigration reliability of a Ag-Pd-Cu alloy (APC) reflector for near UV (385 nm)-LEDs as a function of temperature and compared with those of Ag only reflector. SEM results revealed that the Ag samples were less stable than the APC samples upon annealing. The contact resistivities of the Ag and APC contacts annealed at 500 °C were measured to be 2.59 × 10– 4 and 1.85 × 10–4 Wcm2, respectively. The Ga 2p core level for the APC sample shifted towards the lower binding-energies by 0.67 eV as compared to that of the as-deposited sample. The forward I-V properties of near UV LEDs fabricated with the Ag and APC reflectors were observe to be similar each other. Notably, the UV LEDs with the APC reflector produced 9.04% higher output at 100 mA than those with the Ag reflector. To investigate the device reliability, the EM behaviour of Ag and APC films were also characterised. The APC samples exhibited better EM resistance than the Ag samples. The APC samples yielded higher activation energies of the EM failures than the Ag sample. The better EM behaviour of the APC samples will be described and discussed on the basis of XRD pole figure and electron back scatter diffraction, phi scan, and inverse pole figures (IPFs) examination results.

PVK nanoparticles were obtained by oil-in-water emulsion polymerization of N -vinylcarbazole (VCz). VCz is a white crystalline material with a melting point of 65 °C, which is an unsuitable monomer for conventional emulsion polymerization because of its crystallinity. However, we could successfully synthesize PVK nanoparticles by emulsion polymerization from VCz solution with organic solvent. And then, we found that the concentration of VCz influenced the particle size. PVK hollow particles were also obtained by etching of PMMA core from PMMA/PVK core–shell particles, and the size of a hollow particle was enlarged by two times compared with a core–shell particle due to the swelling process. PVK nanoparticles were probed by UV–vis absorption and fluorescence spectrometers, and hollow particles were characterized by FT-IR spectra. Both of them were confirmed by TEM, and the light-scattering instrument.

In this study, we found that a photoelectric field in nematic liquid crystal (LC) cells that contains dye-sensitized titania (TiO2) layers leads to phase modulation of the LCs. When light is injected into the device, the Ru-dye is excited and electron−hole pairs are generated. The excited electrons then are transited to the conduction band of the TiO2 and transported to the ITO electrode. The holes are transported to the opposite electrode, passing through the LCs and hole-transporting layers. This charge separation by the diffusion process induces a photoelectric field across the LC cells. The birefringence of the LCs was investigated using transmission ellipsometric methods in the absence of external applied voltage. In addition, the electro-optic properties with and without the photoelectric field were compared in twisted nematic LC cells. Furthermore, optically addressed spatial light modulation by the photoelectric field was confirmed using real-time optical images.

This study investigated the association between lipid profiles and insulin resistance and bone mineral content (BMC) in Korean adolescents and found that BMC was inversely associated with triglyceride (TG) and homeostasis model assessment of insulin resistance (HOMA-IR). This association did not differ according to obesity status in either boys or girls. To prevent future osteoporosis, it is important to identify factors that affect bone health in adolescents as well as adults. This study aimed to examine the association between lipid profiles and insulin resistance and BMC in Korean adolescents. Data from 706 boys and 621 girls, who participated in the Korea National Health and Nutrition Examination Survey from 2008 to 2011, were analyzed. Lipid profiles were measured, and HOMA-IR was calculated to assess insulin resistance. BMC was measured for the total femur, femur neck, and lumbar spine by using whole-body dual-energy X-ray absorptiometry (DXA). TG level and HOMA-IR were negatively correlated with BMC at all three sites in boys. In girls, TG level showed a negative correlation with BMC at the femur neck and lumbar spine, and HOMA-IR was negatively associated with BMC at the femur neck only. These inverse associations did not differ according to obesity status in either sex. Adjusted means of BMC at the three sites in boys tended to decrease in the higher tertile groups of TG and HOMA-IR, and the adjusted means of BMC for the total femur in girls tended to decrease in the higher tertile groups of TG and HOMA-IR. BMC was inversely associated with TG and HOMA-IR in Korean adolescents, and this association was more pronounced in boys. This association did not differ according to obesity status in either sex.

This study examined the relationship between a MnSOD gene (MnSOD) polymorphism (Ala-9Val) and mood disorders such as major depressive disorder (MDD) and bipolar I disorder (BD). Eighty patients with BD, 61 patients with MDD and 106 healthy controls were enrolled in this study and genotyped using a polymerase chain reaction-based method. The patients with MDD and BD, and the controls had a similar distribution of the genotypes and alleles in the Ala-9Val MnSOD polymorphism. The combined analysis (MDD plus BD) also failed to find any association between the Ala-9Val MnSOD polymorphism and mood disorders. Subgroup analyses according to the clinical variables such as the family history, age at onset, psychotic features and suicide history failed to identify any association with the Ala-9Val MnSOD polymorphism. This preliminary data suggests that at least in the Korean population, the Ala-9Val MnSOD polymorphism is not associated with the development of mood disorders or their clinical parameters. However, more study with a larger population sample will be needed.

Objectives It has been suggested that oxidative injuries have an important role in the pathogenesis of Alzheimer's disease (AD). In this study, we assess whether the plasma levels of albumin, bilirubin, and uric acid would be altered in the AD patients compared to those of the healthy controls. Furthermore, we tried to find the correlations between plasma antioxidant levels and the cognitive function in AD patients. Methods The plasma albumin, bilirubin, and uric acid levels were measured by standard methods in 101 AD patients and 101 healthy controls. The Korean version of the Mini Mental Status Examination (MMSE-K) was used to evaluate the cognitive functions of AD patients. Results A significant reduction in the albumin, bilirubin, and uric acid levels in the AD group was found compared to those of the control group. The scores of MMSE-K showed the positive correlation with albumin level in the AD group after adjusting confounding factors such as body mass index, gender and age. Conclusion This study showed that oxidative injuries could be involved in the pathogenesis of AD, as well as indicating that some antioxidant might be associated with the cognitive functions in AD. Copyright © 2006 John Wiley & Sons, Ltd.

A hangover is characterized by the unpleasant physical and mental symptoms that occur between 8 and 16 hours after drinking alcohol. After inducing experimental hangover in normal individuals, we measured the methanol concentration prior to and after alcohol consumption and we assessed the association between the hangover condition and the blood methanol level. A total of 18 normal adult males participated in this study. They did not have any previous histories of psychiatric or medical disorders. The blood ethanol concentration prior to the alcohol intake (2.26+/-2.08) was not significantly different from that 13 hours after the alcohol consumption (3.12+/-2.38). However, the difference of methanol concentration between the day of experiment (prior to the alcohol intake) and the next day (13 hours after the alcohol intake) was significant (2.62+/-1.33/l vs. 3.88+/-2.10/l, respectively). A significant positive correlation was observed between the changes of blood methanol concentration and hangover subjective scale score increment when covarying for the changes of blood ethanol level (r=0.498, p

Background: An understanding of the neurophysiological mechanisms underlying alcohol craving is important in the effective treatment of alcohol dependence. The aim of this study was to examine the utility of the electroencephalogram (EEG) to measure the changes in electrical brain activity of alcoholics when exposed to alcohol-specific cues. Methods: Fifteen adult alcoholic subjects (four women) with a mean age of 35 (SD = 4.5) and 10 healthy social drinking controls (three women) with a mean age of 34 (SD = 5.6) were recruited. Subjects were serially rated for alcohol craving after presentations of pictures of control nonalcoholic and alcohol beverages. After the picture presentation, the EEG was recorded (16,384 data points for each epoch) with eyes closed. The dimensional complexity (D 2 ) was estimated as a measure of complexity of the EEG. Results: Alcoholic subjects exhibited a significant increase in the D 2 values of the EEG in frontal (F 3 , F 4 ), right posterior temporal (T 6 ), and occipital (O 1 , O 2 ) regions after viewing alcohol cues compared with viewing other beverage cues. These results indicate that more complex (or higher) cortical activity is induced over specific brain regions of alcoholic subjects by alcohol-specific cues. Changes in subscale of alcohol craving between nonalcoholic and alcohol pictures were correlated with changes in D 2 values in the left frontal (F 3 ) region in alcoholic subjects. Conclusions: These findings suggest that, when subjects are exposed to alcohol cues, changes in the EEG complexity are induced in frontal, right posterior temporal, and occipital areas, which may be key brain structures for alcohol craving. In addition, nonlinear measures like the D 2 are useful in evaluating alcohol cue-induced brain activity from the EEG.

A hangover is the syndrome of physical and mental symptoms that occurs 8 to 16 h after alcohol consumption with a zero level of alcohol. The aim of the current study was to investigate the effects of the alcohol hangover on cytokine production in healthy subjects. The hangover state was defined as 13 h after drinking 1.5 g/kg of alcohol (blood alcohol level=0). A venous blood sample was taken from 20 healthy adult men before consumption of alcohol and during the hangover state. Peripheral blood mononuclear cells were separated and stimulated with phytohemagglutinin. An enzyme-linked immunosorbent assay was used to measure the production of the following cytokines: interleukin (IL)-1beta, IL-4, IL-6, IL-10, IL-12, interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha). We found that the concentrations of IL-10, IL-12, and IFN-gamma were significantly increased during the hangover state compared with the concentrations in normal conditions. These results support the suggestion that the dysregulated cytokine pathway (IL-10, IL-12, and IFN-gamma) is associated with the symptoms of hangovers.

A hangover is characterized by the constellation of unpleasant physical and mental symptoms that occur between 8 and 16 h after drinking alcohol. We evaluated the effects of experimentally-induced alcohol hangover on cognitive functions using the Luria-Nebraska Neuropsychological Battery. A total of 13 normal adult males participated in this study. They did not have any previous histories of psychiatric or medical disorders. We defined the experimentally-induced hangover condition at 13 h after drinking a high dose of alcohol (1.5 g/kg of body weight). We evaluated the changes of cognitive functions before drinking alcohol and during experimentally-induced hangover state. The Luria-Nebraska Neuropsychological Battery was administrated in order to examine the changes of cognitive functions. Cognitive functions, such as visual, memory, and intellectual process functions, were decreased during the hangover state. Among summary scales, the profile elevation scale was also increased. Among localization scales, the scores of left frontal, sensorimotor, parietal-occipital dysfunction, and right parietal-occipital scales were increased during the hangover state. These results indicate that alcohol hangovers have a negative effect on cognitive functions, particularly on the higher cortical and visual functions associated with the left hemisphere and right posterior hemisphere.

BACKGROUND: Albuminuria is associated with cardiovascular disease, and the relationship between albuminuria and hypertension is well established in many studies. So the control of hypertension is critical for decreasing cardiovascular events and albuminuria. Obesity and abdominal obesity are also associated with hypertension and albuminuria. Therefore, we analyzed the relationship between albuminuria and the prevalence and control of hypertension in the general Korean population according to obesity status. METHODS: We analyzed data from the 2011-2012 Korea National Health and Nutrition Examination Survey, and 9,519 subjects were included. Subjects were divided into four groups: non-obese/normal waist circumference, non-obese/high waist circumference, obese/normal waist circumference, and obese/high waist circumference. RESULTS: Systolic blood pressure and diastolic blood pressure were positively associated with albumin-creatinine ratio in all groups (all p values

A variety of cytokines are dysregulated in schizophrenia, and some antipsychotic drugs effect cytokines. In order to examine the effect of risperidone on plasma cytokines, we measured the serum level of IL-1b, IL-2, IL-6, IL-12, and INF-g during acute states of illness, and after 4 weeks of treatment with risperidone in 19 schizophrenic patients. The patients' psychopathology was assessed by PANSS. Plasma IL-12 levels increased significantly after 4 weeks of treatment (p = .002). Plasma IL-b, IL-2, IL-6, and INF-g levels were not significantly different before and after treatment. There were no significant correlations between the changes in cytokine levels and the changes in PANSS scores. Increased IL-12 may contribute to activation of immune responses during treatment with risperidone. IL-12 may play an important role in immune responses related to neuropsychiatry.

Purpose: To evaluate the relationship between organizational socialization and intention to leave, and to identify factors affecting on intention to leave in operating room nurses. Methods: This study used a descriptive design. Seventy operating room nurses recruited from three hospitals under the same management style, in-service educational system, and working conditions agreed to participate in this study, and completed self-administered questionnaires of the organizational socialization and the intention to leave questionnaire. Respondents were classified by career as advanced beginner, competent practitioner, proficient practitioner and expert practitioner by Benner's stages of nursing proficiency. Data were analyzed with t-test, ANOVA with multiple comparisons, Spearman correlation, and multiple regression analysis. Results: Nurses unsatisfied with the current in-service continuous education had lower organizational socialization and higher intention to leave. In advanced beginners, job performance was lowest and organizational commitment was highest. In expert practitioners, intention to leave was highest. Organizational commitment, interpersonal relationship, identity and burnout were associated with intention to leave. Mutual trust, burnout, and interpersonal relationship were predictors of intention to leave explained 20.8% of variance. Conclusion: The career ladder program to enhance nurses' organizational socialization and intention to stay should be established and expanded for well-experienced operating room nurses.

Background: Recent studies have raised the possibility that nerve growth factor (NGF) is abnormally regulated in the central nervous system (CNS) of animal models of chronic ethanol treatment. The goals of this study were to determine whether prolonged alcohol consumption is associated with the plasma NGF levels and to assess the effect of a positive family history of alcohol dependence on plasma NGF levels in the alcohol-dependent patients. Methods: We used the enzyme-linked immunosorbent assay (ELISA) to determine the concentrations of peripheral NGF in patients with alcohol dependence and in a control group. Results: The plasma NGF concentrations in the alcohol-dependent patients were significantly lower than in the controls (71.9 vs 110.5 pg/mL, respectively). Moreover, the alcohol-dependent patients with positive family histories showed a greater decrease in their NGF levels than those subjects with negative family histories (64.7 vs 83.3 pg/mL, respectively). Conclusions: Our study suggests that the NGF levels may be a trait marker for the development of alcohol dependence.

This trial was to evaluate the efficacy and tolerability of venlafaxine extended release (XR) and paroxetine for treatment of patients with generalized anxiety disorder (GAD). Sixty patients who met DSM-IV criteria for GAD were randomly assigned to either venlafaxine XR or paroxetine for 8 weeks. Efficacy was assessed with the Hamilton Rating Scale for Anxiety (HAM-A) and Clinical Global Impression-Severity of Illness (CGI-S) scale at the baseline, week 1, week 4, and week 8. The side-effects were collected with reported adverse events and laboratory tests throughout the study period. Repeated measures analysis of variance (ANOVA) on the HAM-A and CGI-S scores showed a significant decrease over time in both treatment groups without significant group difference or time x group interaction effect. There were no serious adverse events in both groups. This open trial demonstrated that either venlafaxine XR or paroxetine would be effective and tolerable for the treatment of patients with GAD. Double blind, placebo-controlled head-to-head comparison studies are needed to draw a definite conclusion.

Major depressive disorder and alcohol dependence are common and serious mental illnesses. There is a great interest in discovering useful treatments for both mood symptoms and alcohol abuse in those patients with depressive disorders and comorbid alcohol dependence. The primary purpose of this study was to evaluate the effectiveness and tolerability of mirtazapine for the treatment of patients with alcohol dependence comorbid with a depressive disorder in an open label, naturalistic multicentre treatment setting. The 17-item Hamilton Depression Rating Scale (HDRS), the Hamilton Anxiety Rating Scale (HARS) and the Clinical Global Impression-Severity (CGI-S) scale were measured at baseline and at weeks 4 and 8 for the assessment of treatment effectiveness. Alcohol craving was measured using the Obsessive Compulsive Drinking Scale (OCDS) and the Visual Analog Scale for Craving (VAS). This study showed a statistically significant reduction of the scores on the HDRS (13.9+/-7.3, p

Methamphetamine is a highly addictive drug that has a neurotoxic effect on the brain. A growing body of evidence suggests that brain-derived neurotrophic factor (BDNF) is associated with addictive behavior. The present study investigated the changes in plasma BDNF concentration that were induced by chronic methamphetamine use. Using an enzyme-linked immunosorbent assay (ELISA), we measured peripheral BDNF levels in methamphetamine users and in a control group. The plasma BDNF concentrations of methamphetamine users were significantly higher compared with those of controls (2536.3 pg/ml versus 1352.6 pg/ml). This finding suggests that BDNF plays some role in the neurotoxicity of methamphetamine.

Background The current study was conducted to compare the prevalence, severity, and location of white matter signal hyperintensities (WMH) on brain magnetic resonance (MR) imaging in methamphetamine (MA) abusers. Methods Thirty-three MA abusers and 32 age- and gender-matched healthy comparison subjects were studied. Axial T-2 weighted images and fluid attenuated inversion recovery axial images were obtained using 3.0 T MR scanner. The severity of WMH was assessed separately for deep and periventricular WMH. Ordinal logistic regression models were used to assess the odds ratio for WMH. Results MA abusers had greater severity of WMH than the healthy comparison subjects (odds ratio: 7.06, 8.46, and 4.56 for all, deep, and periventricular WMH, respectively). Severity of deep WMH correlated with total cumulative dose of MA (p = 0.027). Male MA abusers had greater severity of WMH than female MA abusers (odds ratio = 10.00). While male MA abusers had greater severity of WMH than male comparison subjects (odds ratio = 18.86), there was no significant difference in WMH severity between female MA abusers and female comparison subjects. Conclusions The current study reports increased WMH in MA abusers, which may be related to MA-induced cerebral perfusion deficits. In addition, female MA abusers had less severe WMH than male MA abusers, possibly due to estrogen's protective effect against ischemic or neurotoxic effects of MA.

Aims: Ghrelin is a peptide hormone that antagonizes the action of leptin and is thereby thought to regulate feeding behaviour. The actions of ghrelin and leptin appear to be mediated by the neuropeptide Y (NPY) and Agouti-related protein (AGRP) system. Recent studies have suggested that leptin and NPY play significant roles in the pathophysiology of alcoholism. The aim of this study was to determine whether ghrelin is associated with the state and duration of abstinence in individuals with alcohol dependence. Methods: Fasting plasma ghrelin levels were compared between 47 individuals with chronic alcoholism during a period of abstinence and 50 control subjects. Results: Fasting plasma ghrelin levels were higher in alcohol abstainers than those in controls. Furthermore, a positive correlation was observed between ghrelin levels and the duration of abstinence. In addition, daily alcohol intake prior to abstinence was inversely related to ghrelin levels. Conclusions: These findings suggest that ghrelin plays a role in the pathogenesis of alcohol dependence, particularly during the abstinence period, in individuals with chronic alcoholism.

In this paper, a relevance feedback method is proposed to improve the retrieval performance of the MPEG-7 edge histogram descriptor. Specifically, by updating the query point and the weighting factors simultaneously, we can reduce the convergence speed of the relevance feedback retrieval. Experimental results show that the proposed method improves the performance significantly for natural and clip art images.