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The emergency conservation of historical objects is necessary because several instances in which paintings and records were flooded owing to unusual weather conditions have recently been reported. Early action is especially important in preventing biodeterioration in case of flood damage. In this study, the feasibility of using gamma rays as a biological control method was assessed. Material stability was evaluated by applying different irradiation doses to natural dyes used in historical paintings and costumes. Sappan wood, gardenia fruit, and indigo were selected and prepared as natural dye samples using standard colorant materials. The fading behavior of the samples was analyzed by measuring their CIE L*a*b* color space values, and UV-Vis spectroscopy and liquid chromatography tandem mass spectrometry (LC-MS) were used to obtain their spectra. We confirmed that the dyes began to decompose upon exposure to gamma rays at a dose of 10 kGy. Irradiation at a dose of 50 kGy led to the complete decomposition of the chromophoric groups because the dye components could not be detected by LC-MS. Therefore, studying the influence of low-dose gamma-ray irradiation is necessary to preserve dye colorants. The data obtained in this study can be used as a foundation for further research on the influence of gamma rays on historical objects.

Antibodies used in this study

Supplementary Figure S1. (A) Immunofluorescence staining of DAPI and α-SMA expression in primary human normal fibroblasts (NF; passage

Purpose: M2-type TAMs are increasingly implicated as a crucial factor promoting metastasis. Numerous cell types dictate monocyte differentiation into M2 TAMs via a complex network of cytokine-based communication. Elucidating critical pathways in this network can provide new targets for inhibiting metastasis. In this study, we focused on cancer cells, CAFs, and monocytes as a major node in this network.Experimental Design: Monocyte cocultures with cancer-stimulated CAFs were used to investigate differentiation into M2-like TAMs. Cytokine array analyses were employed to discover the CAF-derived regulators of differentiation. These regulators were validated in primary CAFs and bone marrow-derived monocytes. Orthotopic, syngeneic colon carcinoma models using cotransplanted CAFs were established to observe effects on tumor growth and metastasis. To confirm a correlation with clinical evidence, meta-analyses were employed using the Oncomine database.Results: Our coculture studies identify IL6 and GM-CSF as the pivotal signals released from cancer cell–activated CAFs that cooperate to induce monocyte differentiation into M2-like TAMs. In orthotopic, syngeneic colon carcinoma mouse models, cotransplanted CAFs elevated IL6 and GM-CSF levels, TAM infiltration, and metastasis. These pathologic effects were dramatically reversed by joint IL6 and GM-CSF blockade. A positive correlation between GM-CSF and IL6 expression and disease course was observed by meta-analyses of the clinical data.Conclusions: Our studies indicate a significant reappraisal of the role of IL6 and GM-CSF in metastasis and implicate CAFs as the “henchmen” for cancer cells in producing an immunosuppressive tumor ecological niche. Dual targeting of GM-CSF and IL6 is a promising new approach for inhibiting metastasis. Clin Cancer Res; 24(21); 5407–21. ©2018 AACR.

Primers used in this study

Oncomine data

Study Objectives This study investigated the altered neural function involved in emotional interference and its role in linking sleep disturbance and depressive/anxiety symptoms in rotating shift workers. Methods Sixty rotating shift workers and 61 controls performed the emotional Stroop task in three blocks (emotional-related, sleep-related, and neutral words) during functional magnetic resonance imaging (fMRI) assessments. Sleep disturbance and depressive/anxiety symptoms were assessed using self-report measures and sleep diaries. Actigraphy was used to assess the sleep and circadian variables. fMRI scans were performed to compare brain activation during the emotional Stroop task. The proposed moderating models were tested using the PROCESS macro in SPSS software. Results A significant condition effect on reaction time was detected. Regardless of the group, reaction times were longer in the negative emotional word and sleep-related conditions than in the neutral word condition. Whole-brain analysis revealed that rotating shift workers show greater neural activation in the left dorsolateral prefrontal cortex (DLPFC) compared with controls while performing the emotional Stroop task with negative emotional words. Sleep disturbance was more strongly associated with depressive symptoms when activation of the left DLPFC was higher during the emotional Stroop task with negative words. Conclusions The left DLPFC may play important roles in increased sensitivity to emotional information, possibly due to circadian misalignment, and has moderating effects on the association between sleep disturbance and depressive symptoms in rotating shift workers. These findings will help to identify possible brain regions where interventions can be performed to correct sleep and mood problems in rotating shift workers.

STUDY OBJECTIVES: In the present study, factors associated with sleep perception were identified by comparing clinical characteristics and polysomnographic variables between insomnia patients with negative and positive sleep state misperception (NSSM and PSSM, respectively). METHODS: Self-reported and objective sleep measures were retrospectively collected, including the Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory, and a questionnaire on “morning feeling” after nocturnal polysomnography in 150 patients with insomnia. Based on the misperception index (MI), participants were classified into NSSM (MI > 0, n = 115) and PSSM (MI < 0, n = 35) groups. RESULTS: The PSSM group had more N3 sleep on nocturnal polysomnography than the NSSM group (P = .002). The NSSM group showed a higher PSQI score (P < .001), longer self-reported sleep-onset latency (SOL) (P = .001), and a greater SOL discrepancy (P = .001). Self-reported feelings of tiredness and morning awakenings in the morning were higher in the NSSM group (P = .029 and P = .038). The MI negatively correlated with a proportion of N3 sleep (P = .005) and positively correlated with PSQI (P < .001), morning awakenings (P = .01), self-reported SOL (P < .001), and SOL discrepancy (P < .001) in patients with insomnia. Multiple regression analysis showed that N3 sleep, PSQI, and morning awakenings were significantly associated with MI in patients with insomnia. CONCLUSIONS: The proportion of slow-wave sleep and self-reported measures may be associated with perception of sleep in patients with insomnia. Objective and self-reported characteristics of patients with insomnia should be carefully evaluated and managed because they may influence the perception of sleep. CITATION: Yoon G, Lee MH, Oh SM, Choi J-W, Yoon SY, Lee YJ. Negative and positive sleep state misperception in patients with insomnia: factors associated with sleep perception. J Clin Sleep Med. 2022;18(7):1789–1795.

STUDY OBJECTIVES: To assess the seasonality of restless legs syndrome (RLS) using data from the Korean national health insurance database. METHODS: We retrospectively reviewed a randomly selected sample representing 3% of the national health insurance claims database in South Korea. From this sample, we obtained the monthly numbers of patients with RLS and diagnoses from 2009 to 2016, along with prescriptions for monthly dopamine agonists and clonazepam for patients with RLS from 2009 to 2013. Total dopamine agonist and clonazepam doses were converted to levodopa-equivalent doses, and the monthly cumulative prescription dose was calculated. Cosinor analysis was used to evaluate the seasonal pattern of each variable. RESULTS: This study included 11,466 patients with RLS and their diagnoses and 4,887 prescriptions for dopamine agonists and clonazepam. There were significant seasonal patterns in the numbers of patients with RLS (P < .001) and diagnoses (P < .001), both of which peaked in August. The magnitude of the greatest difference in the number of patients with RLS between August (highest) and February (lowest) was 29.96% (95% confidence interval, 24.03–100.80), and that of the number of RLS diagnoses was 39.56% (95% confidence interval, 31.24–47.89). The cumulative prescription dose of medication showed no significant seasonality. CONCLUSIONS: Our findings suggest that the prevalence of RLS is seasonally affected, with an increase during summer. CITATION: Oh SM, Son K-L, Choi S-J, Lee MH, Yoon SY, Lee YJ. The seasonal pattern of restless legs syndrome in a sample from the Korean health insurance review and assessment service national database. J Clin Sleep Med. 2021;17(5):1051–1056.

Objective This study was performed to investigate the associations of life event stress with impulsivity, anxiety, and depressed mood as a function of the presence of a sleep disturbance.Methods In total, 214 participants (age 38.96±10.53 years; 111 females) completed self-report questionnaires, including the Life Experience Survey (LES), Pittsburgh Sleep Quality Index (PSQI), Barratt’s Impulsivity Scale (BIS), Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI). The presence of a sleep disturbance was defined as a PSQI score >5.Results In total, 127 participants presented with a sleep disturbance (age 39.33±10.92 years; 64 females), whereas the remaining 87 did not (age 38.43±9.97 years; 47 females). Negative LES scores were significantly correlated with BIS (r=0.22, p=0.001), BAI (r=0.46, p< 0.001), and BDI (r=0.51, p

Objectives: Evidence suggests that emotion regulation difficulty may play an important role in the association between life stress, sleep disturbance and depressive symptoms. We proposed two models depicting the possible moderating roles of prefrontal cortex activation during emotion regulation in the associations among these variables and tested them. We hypothesized that (1) the association between stress and sleep disturbance would differ across prefrontal cortex activation during emotion regulation (moderation model) and (2) the indirect effects of stress on depressive symptoms through sleep disturbance would depend on prefrontal cortex activation during emotion regulation (moderated mediation model). Methods: Forty-eight healthy adults without sleep disorders based on nocturnal polysomnography participated in this study. They received functional magnetic resonance imaging scans while performing an emotion regulation task. They also completed questionnaires assessing life stress, sleep disturbance and depressive symptoms. The proposed models were tested using the PROCESS macro for SPSS. Results: As hypothesized, there was a significant moderating effect of prefrontal cortex activation during emotion regulation on the association between life stress and sleep disturbance. Furthermore, right lateral prefrontal cortex activation had a moderating role in the indirect effect of life stress on depressive symptoms through sleep disturbance. Conclusion: These findings highlight the important role of prefrontal cortex function during emotion regulation in the associations between stress, sleep disturbance and depressive symptoms. Increasing lateral prefrontal cortex recruitment when regulating the emotional response to negative life events may be critical for the prevention and intervention of depression as well as sleep problems.

This study investigated the effects of anterior insula (AI) activation on the association between stress and sleep disturbance as a neurobiological basis of the trait-like degree of sleep reactivity to stress. Additionally, it examined the effects of AI activity on the association between sleep disturbance and depression.The participants were 48 adults. To assess AI activation in response to sleep-related stimuli (SS) compared to neutral stimuli (NS), we extracted mean AI parameter estimates for the SS-NS contrast. We examined whether the interaction between life stress and AI activation would predict sleep disturbance and whether the interaction between sleep disturbance and AI activation would predict depression.At higher levels of bilateral AI activation in response to SS, higher levels of stress were associated with greater sleep disturbance (left AI x stress: b = 1.07, SE = 0.44, p 0.05; right AI x stress: b = 1.05, SE = 0.48, p 0.05). In addition, at higher levels of right AI activation, higher levels of sleep disturbance were associated with more severe depressive symptoms (right AI x sleep disturbance: b = 2.55, SE = 1.10, p 0.05).This study assessed sleep quality and depressive symptoms based on self-reported questionnaires.This study revealed moderating effects of AI activation on the association between negative life stress and sleep disturbance. Additionally, AI activation strengthened the association between sleep disturbance and depression. AI activation may reflect a crucial etiological diathesis for insomnia and stress-related disorders.

Aim Patients with psychophysiological insomnia (PI) experience hyperarousal, especially as a reaction to sound stimuli. In the current study, we explored brain activity changes in response to sleep-related sounds (SS) in patients with insomnia after cognitive behavioral therapy for insomnia (CBT-I). Methods In 14 drug-free PI patients, regional brain activity in response to SS, and to white noise sound (NS) as neutral stimuli, was investigated before and after individual CBT-I using functional magnetic resonance imaging. Blood oxygen level-dependent (BOLD) signals to SS and NS were compared before and after CBT-I. In addition, the association between clinical improvement after CBT-I and changes in brain activity in response to SS and NS was analyzed. Results Compared with baseline, regional brain activity in response to SS after CBT-I decreased in the left middle temporal and left middle occipital gyrus. In regression analysis, a reduction in the Dysfunctional Beliefs and Attitudes about Sleep (DBAS) Scale score after CBT-I was associated with decrease in brain activity in response to SS in both thalami. However, brain activity in response to NS showed no BOLD signal changes and no association with DBAS change. Conclusion Cortical hyperactivity, which may cause hyperarousal in PI, was found to decrease after CBT-I. CBT-I targeting changes in beliefs and attitudes about sleep may induce its therapeutic effects by reducing thalamic brain activity in response to sleep-related stimuli.

STUDY OBJECTIVES: Idiopathic rapid eye movement sleep behavior disorder (iRBD), characterized by rapid eye movement sleep without atonia (RSWA) and dream-enactment behavior, has been suggested to be a predictor of α-synucleinopathies. Autonomic instability, represented by heart rate variability, is a common characteristic of both iRBD and α-synucleinopathies. Previous studies reported that RSWA was associated with autonomic dysfunction and was a possible predictor of phenoconversion. Therefore, we sought to compare heart rate variability between iRBD and control groups and explore the relationship between heart rate variability and RSWA in patients with iRBD. METHODS: Nocturnal polysomnographic data on 47 patients (28 men, 19 women) diagnosed with iRBD based on video-polysomnography and 26 age-matched and sex-matched controls were reviewed. The first 5-minute epoch with a stable electrocardiogram lead II on video-polysomnography was selected from stage N2, wake, and rapid eye movement. For quantification of RSWA, tonic activity was analyzed from the submentalis electromyogram and phasic activity from the submentalis and bilateral anterior tibialis electromyogram channels. RESULTS: Compared to the control group, the iRBD group showed significant reductions in the standard deviation of the R-R intervals, the root mean square of successive R-R interval differences, and high-frequency values. Quantified tonic activity was inversely correlated with normalized low-frequency values and low-frequency/high-frequency ratios and positively correlated with normalized high-frequency values. CONCLUSIONS: This study implied decreased cardiac autonomic function in patients with iRBD, which showed parasympathetic predominance. Heart rate variability of the patients with iRBD in this study was associated with quantified tonic RSWA, which was previously reported to be a possible predictor of phenoconversion. CITATION: Yang JH, Choi SH, Lee MH, et al. Association of heart rate variability with REM sleep without atonia in idiopathic REM sleep behavior disorder. J Clin Sleep Med. 2021;17(3):461–469.

We investigated the differential spatial covariance pattern of blood oxygen level-dependent (BOLD) responses to single-task and multitask functional magnetic resonance imaging (fMRI) between patients with psychophysiological insomnia (PI) and healthy controls (HCs), and evaluated features generated by principal component analysis (PCA) for discrimination of PI from HC, compared to features generated from BOLD responses to single-task fMRI using machine learning methods. In 19 patients with PI and 21 HCs, the mean beta value for each region of interest (ROIbval) was calculated with three contrast images (i.e., sleep-related picture, sleep-related sound, and Stroop stimuli). We performed discrimination analysis and compared with features generated from BOLD responses to single-task fMRI. We applied support vector machine analysis with a least absolute shrinkage and selection operator to evaluate five performance metrics: accuracy, recall, precision, specificity, and F2. Principal component features showed the best classification performance in all aspects of metrics compared to BOLD response to single-task fMRI. Bilateral inferior frontal gyrus (orbital), right calcarine cortex, right lingual gyrus, left inferior occipital gyrus, and left inferior temporal gyrus were identified as the most salient areas by feature selection. Our approach showed better performance in discriminating patients with PI from HCs, compared to single-task fMRI.

This study investigated prescriptions for sedative–hypnotics via data obtained from the Health Insurance Review and Assessment (HIRA) service. Data on sedative–hypnotic prescriptions from the HIRA service of the Republic of Korea were analyzed from 2011 to 2015. We included prescriptions for subjects > 18 years of age from hospitals and community healthcare centers. In addition, subgroup analyses with a subsample restricted to prescriptions from patients with diagnostic codes F510 (nonorganic insomnia) or G470 (insomnia) were performed. After analyzing the number of prescriptions by individual pharmacy items, the prescription codes were grouped as: (1) benzodiazepines; (2) non-benzodiazepines, including zolpidem; (3) antidepressants; and (4) antipsychotics. We calculated the monthly percent change in the number of prescriptions by drug group using Joinpoint regression. Among the sedative–hypnotic groups, benzodiazepines were the most commonly prescribed drugs in Korea during the study period. As a single sedative–hypnotic item, zolpidem was the most frequently prescribed medication for patients with insomnia. Prescriptions for all groups of sedative–hypnotics increased significantly during the study period. When stratified by age group, antipsychotic prescriptions increased significantly by 0.19–0.21% per month among men and women aged 50–59 years and > 70 years. Prescriptions for antidepressants in 30–39-year-old men increased significantly by 0.20%. Benzodiazepine prescriptions as well as those for antipsychotics and antidepressants to treat insomnia increased during 2011–2015 in Korea. Monitoring the use of sedative–hypnotics at the national level is necessary, especially in the elderly population.

We used quantitative electroencephalography (EEG) spectral analysis to compare activity in the bilateral frontal, central, and occipital areas in nine patients with schizophrenia and ten healthy control subjects during standard nocturnal polysomnography. Patients with schizophrenia had longer sleep latency than controls. In N2 sleep, the patients had significantly lower 0.5-1 Hz power and higher theta power in the left frontal region, and higher beta power in the left occipital region than did control subjects. In N3 sleep, the patients with schizophrenia had significantly higher alpha power in the left occipital region than did controls. These findings show distinctive EEG sleep patterns in patients with schizophrenia, which may reflect brain dysfunction or medication effects.

Introduction Most of insomnia patients tend to underestimate their sleep duration and quality. In current study, we classified insomnia patients into negative sleep state misperception (NSSM) group and positive sleep state misperception (PSSM) group according to difference between subjective and objective sleep duration. We compared clinical and polysomnographic characteristics between two groups. Methods Objective sleep measures using nocturnal polysomnography (nPSG) and subjective measures including Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory (BDI) and subjective questionnaire at the morning after overnight nPSG of 150 insomnia patients were reviewed. The questionnaire included subjective total sleep time (subjective TST), subjective sleep latency (subjective SL). Additionally, TST/SL discrepancy was calculated by subtracting objective variables of nPSG from the morning subjective questionnaire. We calculated misperception index (MI) using the following method; MI=(objective TST-subjective TST)/objective TST. According to MI value, insomnia patients were classified into NSSM (MI>0, n=115), and PSSM (MI Results There were no significant differences in nPSG parameters, except N3 sleep (%); the PSSM group had significantly higher N3 sleep than NSSM group (p=0.002). On the subjective measures, the NSSM group had significantly higher PSQI score (p Conclusion In the NSSM group, MI was related with high SL discrepancy and depressive mood. High N3 sleep, low PSQI score, and low SL discrepancy were associated factors in the PSSM group. Perception of sleep should be properly evaluated and managed, since they vary with different characteristics of sleep state misperception. Support (if any) This study was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF-2018R1D1A1B07049704).

Purpose: M2-type TAMs are increasingly implicated as a crucial factor promoting metastasis. Numerous cell types dictate monocyte differentiation into M2 TAMs via a complex network of cytokine-based communication. Elucidating critical pathways in this network can provide new targets for inhibiting metastasis. In this study, we focused on cancer cells, CAFs, and monocytes as a major node in this network. Experimental Design: Monocyte cocultures with cancer-stimulated CAFs were used to investigate differentiation into M2-like TAMs. Cytokine array analyses were employed to discover the CAF-derived regulators of differentiation. These regulators were validated in primary CAFs and bone marrow-derived monocytes. Orthotopic, syngeneic colon carcinoma models using cotransplanted CAFs were established to observe effects on tumor growth and metastasis. To confirm a correlation with clinical evidence, meta-analyses were employed using the Oncomine database. Results: Our coculture studies identify IL6 and GM-CSF as the pivotal signals released from cancer cell–activated CAFs that cooperate to induce monocyte differentiation into M2-like TAMs. In orthotopic, syngeneic colon carcinoma mouse models, cotransplanted CAFs elevated IL6 and GM-CSF levels, TAM infiltration, and metastasis. These pathologic effects were dramatically reversed by joint IL6 and GM-CSF blockade. A positive correlation between GM-CSF and IL6 expression and disease course was observed by meta-analyses of the clinical data. Conclusions: Our studies indicate a significant reappraisal of the role of IL6 and GM-CSF in metastasis and implicate CAFs as the “henchmen” for cancer cells in producing an immunosuppressive tumor ecological niche. Dual targeting of GM-CSF and IL6 is a promising new approach for inhibiting metastasis. Clin Cancer Res; 24(21); 5407–21. ©2018 AACR.

Moderately functionalized graphenes, prepared by the thermal reduction of graphite oxide, were utilized to prepare electroconductive graphene/nylon 6 composites which exhibited a highest conductivity value of 6.84 × 10−4 S cm−1 for a low carbon incorporation of 0.54 wt% and a lowest percolation threshold of 0.39 wt%, the lowest values reported so far for graphene/nylon 6 composites. The functionality of the graphenes was modulated by the thermal reduction time. The graphitic structure of graphene was strengthened by extended thermal treatment. The main strengthening mechanism in the first 5 min was the generation of new sp2 domains followed by the growth of the domains during the next 5 min. This extended thermal treatment improved the conductivity of the graphene itself as well as the composite loaded with graphene. However, it led to poor dispersion of the graphene in the composites, reduced crystallization of nylon 6 and reduced reinforcement of nylon 6 by graphene. © 2013 Society of Chemical Industry

Crop safety in heavy metal contaminated agricultural field has been a critical issue in Korea and various remediation methods are proposed for minimizing heavy metal transfer from soil to crops. The main objective of this research was to evaluate remediation efficiency of two chemical amendments, lime and steel slag, and to decide extractant for assessing bioavailability of heavy metals. In order to select optimum extractant for evaluating bioavailability of heavy metals, four different single extractants, HCl, DTPA, , , and sequential extraction method were examined. Both chemical amendments showed high immobilization effect for Cd (66%, ) and Pb (74%, ) in soil by HCl extractant. In terms of heavy metal concentration in rice grains, concentrations for Cd (77%, ) and Pb (82%, ) decreased, with addition of chemical amendments. HCl, DTPA, and sequential extractant showed the higher correlation between heavy metal concentration in soil and crops than others. These results indicated that they could be used for assessing bioavailability of heavy metals.

This paper describes the design of a palette-type 60watt high power amplifier module using gallium nitride(GaN) devices with high power and efficiency performances for WiMAX and LTE systems. The line-up for the high gain amplifier module consists of the pre-amplifier stage with low power and high gain, 8watt GaN driving amplifier stage, and 60watt GaN high power amplifier stage of Doherty structure with two 30watt GaN devices. The obtained gain is 61.4dB with an excellent gain flatness of 0.075dB over 2.5~2.68GHz. GaN devices and the Doherty structure are adopted for the improvement of high efficiency and output power. The measurement for the fabricated high power amplifier module of palette type is performed using the widely known WiMAX signal all over the world. In the example of RRH(remote radio head) application of the fabricated amplifier module, the measured efficiency is 37~38% with the 10watts of modulated output power. It is shown that when the fabricated amplifier module is activated with a digital predistorter(DPD), the measured ACLR is better than 46dBc under the 10watts of modulated output power.

This paper describes the optimized output performances such as output power and the third order intermodulation in GaN high power transistor packages which consist of chip die, chip capacitors, and wire bonding. The optimized output power according to wire bonding techniques, and third order intermodulation performances according to wire bonding and bias conditions are discussed. In addition, it is shown through the nonlinear simulation that how the output performances are sensitive to the inductance values which are realized by wire bonding for matching network in the limited package area.

A novel 1:4 unequal wilkinson power divider using rectangular-shaped defected ground structure(DGS) in double layered substrate is proposed for removing the ground problem of DGS in packaging. Rectangular-shared DGS produces the transmission line having much higher characteristic impedance than standard microstrip line. The proposed unequal divider is composed of DGS and double layered substrate in order to be free from the ground problem of DGS patterns in packaging in metal housings. The second substrate is attached to the first substrate which contains DGS pattern on its ground plane at the bottom side to form the double layered substrate. In order to show the validity of the proposed DGS in the double layered substrate, a 1:4 unequal power divider is designed and measured. The predicted and measured performances are shown with an excellent agreement between them.

A new resonator using active device and defected ground structure with islands (DGSI) is proposed. The active device is used for supplying the negative resistance which is one of key factors of the proposed active resonator. The negative resistance is realized by the series active device. The electrical characteristics of the proposed resonator with DGSI are improved by combining the negative resistance and the microstrip line with DGSI where the electric field is the most strong. It is shown that the measured improvement in S21 and Sll of the proposed active resonator with DGSI are 4.55 dB and 0.32 dB, respectively, at the resonant frequency compared to the previous DGSI resonator without active device.

In this paper, an unequal 1:N Wilkinson power divider with variable power dividing ratio is proposed. The proposed unequal power divider is composed of the conventional Wilkinson divider structure, rectangular-shaped defected ground structure (DGS), island in DGS, and varactor diodes of which capacitance is adjustable according to bias voltage. The high impedance value of microstrip line having DGS is going up and down by adjusting the bias voltage for varactor diodes. Output power dividing ratio (N) is adjusted from 2.59 to 10.4 for the unequal power divider with 2 diodes.

An unequal Wilkinson power divider having rectangular-shaped defected ground structure (DGS) is proposed. DGS microstrip line adopted for the divider is composed of double-layer substrate which removes the ground problem of the previous DGS structures in packaging. The first layer includes DGS on the bottom ground plane. The second substrate of which top metal plane has been removed is attached to the bottom plane of the first layer. At first, a conventional DGS unequal Wilkinson power divider is designed according to the previous method on the first layer, and the second substrate is attached. The proposed DGS with double-layer substrate is described in detail and applied to 1:4 unequal dividers as an application example. The measured unequal Wilkinson power divider has an excellent agreement between prediction and measurement.

An ultra-wideband coplanar waveguide (CPW) balun for operation over 800–5000 MHz using a commonly used hybrid microwave substrate is proposed. The CPW balun consists of a multistage Wilkinson structure, an ‘X’-shaped phase inverting structure, bottom-bridges and via-holes. The proposed balun does not need any additional circuit area for the generation of out-of-phase characteristics, so its size is exactly that of the basis Wilkinson divider.

This report describes the perioperative anesthetic management for surgical separation of xypho- omphalopagus conjoined twins. Male conjoined twins were delivered by cesarian section after 36 weeks plus 2 days gestation. A preoperative functional evaluation was performed in assessing the feasibility of surgical separation. A partial communication of the lower margin of the sternum and a union of the livers were found but with separate biliary and vascular systems. One twin (twin-B) had a small ASD. The twins were separated at 5 days of the birth. After induction with ketamine and succinylcholine, both infants were intubated and inhalated with isoflurane, NO and O respectively. Continuous arterial pressure via the femoral artery and central venous pressure via the internal jugular vein were monitored. During the induction of anesthesia, an injected bolus of ketamine and succinylcholine to one twin was not effective for the other twin. Inhaled isoflurane in one twin did not appear in the expired gas of the other twin. During the operation, the intentional hemorrhage from one twin (twin-B) caused a reduction to some degree of blood pressure and SpO2. in the other twin We must be carefisl in the anesthetic management of the surgical separation of conjoined twins to consider pharmacological and crcrs-circulation pathophysiology. (Korean J Anesthesiol 2000; 39: 134~ 140)