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The purpose of this study was to assess the relationship between quality of life and dementia caregivers. The 2019 Korean Community Health Survey participants were assessed using the Patient Health Questionnaire-9, subjective cognitive decline (SCD) and SCD-related functional limitation, and EuroQol 5-dimension (EQ-5D). Sociodemographic and psychosocial variables were evaluated and compared between participants with dementia caregivers (n = 37,614) and non-dementia caregivers (n = 140,518). The dementia caregivers group reported significantly higher rates of depression, SCD, SCD-related functional restriction, and mean EQ-5D compared to the non-dementia caregivers group (P < .001). After adjusting for multiple confoundings, the odds ratio (OR) for depression (Patient Health Questionnaire-9 ≥ 10), SCD, SCD-related functional limitation, and lowest quartile of the EQ-5D index scores in the dementia caregivers group were 1.43 (95% confidence interval [CI], 1.29–1.59), 1.30 (95% CI: 1.24–1.36), 1.26 (95% CI: 1.20–1.32), and 1.22 (95% CI: 1.16–1.29), respectively. Physical activity (OR: 1.47; 95% CI: 1.43–1.52), self-control (OR: 1.41; 95% CI: 1.35–1.47), daily activity (OR: 1.55; 95% CI: 1.50–1.60), pain (OR: 1.62; 95% CI: 1.58–1.67), and anxiety/depression (OR: 2.17; 95% CI: 2.10–2.24) were all more common among participants in the dementia caregivers group than in the non-dementia family caregivers group. Depression, SCD, and a lower quality of life are linked to dementia caregivers, especially if there is moderate to severe anxiety or depression.

Background The treatment options for odontogenic sinusitis (OS) include medical management including antibiotics and saline nasal irrigation, endoscopic sinus surgery (ESS), and dental treatment.Objective The purpose of this study was to evaluate whether OS caused by dental caries and periapical abscess can be cured by dental treatment alone and which patients should consider surgery early.Methods A total of 33 patients with OS caused by dental caries and periapical abscess were enrolled. Patients with OS caused by dental implants, trauma, surgery, or tooth extraction were excluded. All patients were initially treated with dental treatment and medical management without ESS. The patients were divided into two groups according to the results of dental treatment and multiple clinical parameters were compared between the two groups.Results Among the 33 enrolled patients, 22 patients (67%) were cured with dental and medical management, and 11 patients (33%) required ESS after the failure of dental and medical management. Based on the multivariate analysis results, patients who were smokers (OR 33.4) and had a higher Lund-Mackay score on CT (OR 2.0) required ESS after the failure of dental and medical treatment.Conclusions Two-thirds of the patients with OS caused by dental caries and periapical abscess were cured with dental treatment and medical management without ESS. We recommend dental treatment and medical management first in OS caused by dental caries and periapical abscess. However, we recommend early ESS in patients with smoking habits and severe CT findings of the sinus.

IMPORTANCE: The association between hypertension and epistaxis has long been a subject of debate. OBJECTIVES: To evaluate the risk of epistaxis in patients with hypertension using a nationwide population cohort and to assess the association of hypertension with the methods of managing cases of epistaxis. DESIGN, SETTING, AND PARTICIPANTS: In this retrospective cohort study, a hypertension cohort and comparison cohort were built using the Korean National Health Insurance Service–National Sample Cohort that represents the entire population of the Republic of Korea from January 1, 2002, to December 31, 2015. The hypertension cohort comprised 35 749 patients with a record of 3 or more prescriptions of antihypertensive medication and a diagnosis of hypertension (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision code I10). Patients with other diseases associated with epistaxis, such as sinonasal tumors, facial trauma, bleeding tendency, and coagulation disorder, as well as those taking anticoagulant medications, were excluded. A comparison cohort comprised 35 749 individuals without hypertension matched sociodemographically in a 1:1 ratio. Statistical analysis was performed from January 1, 2019, to March 31, 2020. MAIN OUTCOMES AND MEASURES: The incidence and recurrence of epistaxis were evaluated in both cohorts. The risk factors for epistaxis and management strategies were also assessed. RESULTS: Among the 35 749 patients in the hypertension cohort (20 579 men [57.6%]; median age, 52 years [interquartile range, 45-62 years]) the incidence rate (IR) of epistaxis was 32.97 per 10 000 persons (95% CI, 30.57-35.51 per 10 000 persons); among the 35 749 individuals in the comparison cohort (20 910 men [58.5%]; median age, 52 years [interquartile range, 45-62 years]), the IR of epistaxis was 22.76 per 10 000 persons (95% CI, 20.78-24.89 per 10 000 persons) (IR ratio, 1.45; 95% CI, 1.29-1.63; adjusted hazard ratio, 1.47; 95% CI, 1.30-1.66). The IR of recurrent epistaxis was 1.96 per 10 000 persons in the hypertension cohort and 1.59 per 10 000 persons in the nonhypertension cohort (IR ratio, 1.23; 95% CI, 0.77-2.00). Patients with hypertension who experienced epistaxis were more likely to use the emergency department (odds ratio, 2.69; 95% CI, 1.70-4.25; Cohen h effect size, 0.27; 95% CI, 0.16-0.39) and receive posterior nasal packing (odds ratio, 4.58; 95% CI, 1.03-20.38; Cohen h effect size, 0.15; 95% CI, 0.03-0.26) compared with the comparison cohort. CONCLUSIONS AND RELEVANCE: This study suggests that patients with hypertension had an increased risk of epistaxis requiring hospital visits. In addition, epistaxis in patients with hypertension appeared to need more emergency department visits and require more posterior nasal packing procedures compared with patients without hypertension. Medical counseling about epistaxis is advisable for individuals with hypertension, and the presence of hypertension should be considered in managing nasal bleedings.

Objectives: Foreign bodies (FBs) in external auditory canal (EAC) can occur at any age but are especially common in children and adolescents. The aims of the study were to evaluate the clinical characteristics of EAC FBs in children and adolescents and to discuss their proper management.Methods: A retrospective medical chart review was performed on patients who were treated for EAC FBs in a tertiary referral center from January 2007 to December 2017. We investigated the parameters of age, sex, type of FB, sedation method, complications, and removal strategy.Results: Of 284 patients, 176 (62.0%) were male. Peak incidences were noted at the ages of 3 to 6 years and 17 to 18 years. The frequently observed FBs were insects, followed by air-gun pellets, cotton balls, marbles, and earrings. Forty-one (14.4%) EAC FBs were removed with the naked eye, while 243 (85.6%) were removed under microscope in the otolaryngology department. Of these patients, 23 (9.5%) were administered sedatives and 1 (4.1%) needed general anesthesia. During or after the removal procedure, 4 (15.5%) patients had complications of EAC abrasion or laceration (42, 14.8%), and tympanic membrane perforation (2, 0.7%).Conclusions: External auditory canal FB showed a distinct characteristic of incidence regarding age, related to removal strategies. Characteristics of FB must be considered for safe removal.

Objectives: It is extremely difficult to obtain ideal tip projection and nose lengthening by septal extension graft using only septal cartilage in Asians, because their nasal septal and alar cartilages are small and weak. Therefore, we introduce a new septal extension graft using a cartilage–bone complex with the vomer and the perpendicular plate of the ethmoid bone as well as cartilage to obtain optimal outcomes.Methods: Participants included 30 patients who underwent surgery by external approach. The septal cartilage, vomer, and perpendicular plate of the ethmoid bone harvested by septoplasty were used. There were 2 layers of cartilage on each side and bone in between to create a strong cartilage–bone complex for projection and lengthening. The bony portion was placed in the tip side, and the double-layered cartilage portion was placed in the inferior portion of the caudal septum of the L-strut to create powerful fixation.Results: There were statistically significant improvements in nasal length (4.71 ± 0.65 vs 5.15 ± 0.53 cm, Pvalue <.0001), tip projection (2.66 ± 0.40 vs 3.18 ± 0.42, Pvalue <.0001), and nasolabial angle (94.0° ± 9.3° vs 107.2° ± 9.6°, Pvalue <.0001) postoperatively. All patients were subjectively satisfied, and 2 different surgeons had excellent or good opinions in 28 (94%) patients.Conclusions: The sandwich technique using cartilage and bone complex results in satisfactory outcomes with stronger tip support, especially in Asians with a weak nasal tip who desire ideal tip projection and dramatic change.

A quantum spin liquid is a state of matter where unpaired electrons’ spins, although entangled, do not show magnetic order even at the zero temperature. The realization of a quantum spin liquid is a long-sought goal in condensed-matter physics. Although neutron scattering experiments on the two-dimensional spin-1/2 kagome lattice ZnCu3(OD)6Cl2and triangular lattice YbMgGaO4have found evidence for the hallmark of a quantum spin liquid at very low temperature (a continuum of magnetic excitations), the presence of magnetic and non-magnetic site chemical disorder complicates the interpretation of the data. Recently, the three-dimensional Ce3+pyrochlore lattice Ce2Sn2O7has been suggested as a clean, effective spin-1/2 quantum spin liquid candidate, but evidence of a spin excitation continuum is still missing. Here, we use thermodynamic, muon spin relaxation and neutron scattering experiments on single crystals of Ce2Zr2O7, a compound isostructural to Ce2Sn2O7, to demonstrate the absence of magnetic ordering and the presence of a spin excitation continuum at 35 mK. With no evidence of oxygen deficiency and magnetic/non-magnetic ion disorder seen by neutron diffraction and diffuse scattering measurements, Ce2Zr2O7may be a three-dimensional pyrochlore lattice quantum spin liquid material with minimum magnetic and non-magnetic chemical disorder.

This study aimed to investigate the prognostic value of metabolic tumor volume (MTV) and total lesion glycolysis (TLG), which are volume-based PET parameters, using 18F-2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with surgically resectable lung adenocarcinoma. We retrospectively evaluated 149 patients with lung adenocarcinoma who underwent 18F-FDG PET/CT before surgical resection. Maximum standardized uptake value (SUVmax), MTV, and TLG of the primary tumor with threshold value of SUVmax 30, 40, and 50% were calculated, respectively. To compare the predictive performance of volume-based PET parameters, recurrence-free survival was assessed using the Kaplan-Meier method. The study included 70 males and 79 females with an average age of 65.8 years. The median follow-up time was 45.4 months. Recurrence was observed in 53 patients (35.6%). The mean ± SD SUVmax, MTV30%, and TLG30%of the entire cohort were 4.79 ± 2.94, 19.45 ± 24.85, and 56.43 ± 101.88, respectively. The cut-off values of MTV30%and TLG30%for recurrence were 11.07 ad 30.56, respectively. The 1-year recurrence-free survival (RFS) rate was 96.5% in low-MTV30%patients compared with 86.2% in high-MTV30%patients (p= 0.018) and 96.0% in low-TLG30%patients compared with 88.5% in high-TLG30%patients (p< 0.001). On univariate and multivariate analysis, TLG30%(HR, 2.828, p< 0.001; HR, 2.738, p< 0.001, respectively) was an independent prognostic factor for predicting recurrence-free survival (RFS). TLG30%value was observed to be a significant prognostic factor for RFS in patients with lung adenocarcinoma treated by surgical resection.

Aims and background: Distinction between primary lung adenocarcinoma and metastatic adenocarcinoma from extrapulmonary origin in solitary pulmonary nodule (SPN) is crucial for cancer treatment. We investigated the predictive role of dual-time-point 18F-FDG PET/CT to distinguish primary and metastatic lung adenocarcinoma in SPN.Methods: A total of 96 consecutive patients with newly diagnosed SPN and biopsy-proven adenocarcinoma were enrolled in this study, retrospectively (54 male; 42 female; age 59.68 ± 8.2 years). They all underwent dual-time-point 18F-FDG PET/CT at 60 minutes (early) for whole body and 120 minutes (delayed) for chest region after FDG injection. Maximum standardized uptake values (early SUVmax and delayed SUVmax) and retention index (RI) were acquired for analysis. Final pathology results were confirmed by surgical specimens.Results: Metastatic adenocarcinoma showed significantly higher early SUVmax, delayed SUVmax, and RI compared to primary lung adenocarcinoma. Delayed SUVmax and RI presented superior diagnostic performance for prediction of metastatic adenocarcinoma than early 18F-FDG PET/CT. Among metastatic adenocarcinoma, metastasis from colorectal origin showed significantly higher RI than from other origins. In addition, RI significantly predicted metastatic adenocarcinoma from colorectal cancer than early or delayed SUVmax.Conclusions: Dual-timepoint 18F-FDG PET/CT can be useful to distinguish primary and metastatic lung adenocarcinoma in SPN. Furthermore, it may also be useful to predict metastatic adenocarcinoma from colorectal origin.

To find the effect of coronavirus disease 2019 (COVID-19)-related sleep behavior changes using school-based self-reported data from a nationally representative Korean adolescent population. We analyzed web-based self-reported data from the Korean Youth Risk Behavior Web-based Survey in 98,126 participants (51,651 in 2019 [before the COVID-19 pandemic]; 46,475 in 2020 [during COVID-19 pandemic] 12 through 18 years old were included in this study. Self-report questionnaires were used to assess socioeconomic status, health behaviors, psychological factors, and sleep patterns. During the COVID-19 pandemic, Korean adolescents had a later weekend bedtime (≥1:00 am: 68.2% vs 71.5%, P< .001) and late weekend wake time (≤7:00 am: 13.3% vs 10.7%, P< .001) compared to before COVID-19 pandemic. Average sleep duration (434.7 ± 102.6 vs 428.2 ± 100.4 minutes; P< .001) was significantly lower during the COVID-19 pandemic and weekend catch-up sleep >2 hours (42.1% vs 43.7%; P< .001), late chronotype (17.1% vs 22.9%, P< .001) were significantly higher during COVID-19 pandemic. After adjusting for multiple confounding variables, short sleep duration (≦5 hours, odds ratio [OR] 1.14; 95% confidence interval [CI] 1.10–1.19), 6 hours, OR 1.07; 95% CI 1.03–1.12), long weekend catch-up sleep (OR, 1.08; 95% CI, 1.06–1.11) and late chronotype (OR, 1.43; 95% CI, 1.38–1.47) were significantly associated with COVID-19 pandemic. The COVID-19 pandemic was associated with changes in sleep behavior among Korean adolescents, resulting in later bed and wake-up times, increased weekend catch-up sleep, and a shift of chronotype toward eveningness.

The depth-resolved magnetic configuration of a Ga0.97Mn0.03As/GaAs:Be multilayer with an antiferromagnetic interlayer exchange coupling was investigated using surface-sensitive soft x-ray resonant magnetic reflectivity (XRMR). We observed intriguing opposite increments in the XRMR intensities at the half-Bragg peak position between two different remanent states with opposite field sweep directions. A quantitative analysis shows that these opposite intensity increments result from two different anti-parallel spin configurations in such a way that the magnetization of top-most magnetic layer is pinned along the saturation magnetization direction before the remanent state. This surface pinning effect is important for understanding spin-dependent transport in semiconducting magnetic multilayers.

Background:The aim of this study is to examine whether oral hygiene and self‐care, particularly in periodontal health, are associated with chronic obstructive pulmonary disease (COPD) in the Korean population. Methods:Data from the Korean National Health and Nutrition Examination Survey from 2010 to 2012 were used to assess the community periodontal index (CPI) of 5,878 participants (normal lung function: n = 5,181; obstructive spirometric pattern: n = 697) aged ≥40 years, who underwent spirometry. Results:Participants with COPD brushed their teeth less frequently and used the following less frequently: 1) dental floss and/or interdental brush; 2) mouthwash; and 3) electric toothbrush (P<0.001). Prevalence of periodontitis in patients with COPD (58.1%) was significantly higher than in those without COPD (34.0%, P<0.001). Number of teeth was significantly lower in patients with COPD compared with controls. Decayed‐missing‐filled tooth index was significantly lower in patients with COPD. This study shows risk of COPD by periodontal severity. Periodontitis (CPI 3 and 4) was associated in males with COPD after adjustment for: 1) age; 2) income; 3) education; 4) smoking; 5) alcohol consumption; 6) exercise; 7) body mass index; 8) toothbrushing frequency; 9) diabetes mellitus; and 10) number of teeth (CPI 3: relative risk [RR] = 1.38, 95% confidence interval [CI] = 1.12 to 2.05; CPI 4: RR = 1.23, 95% CI = 1.06 to 1.56). Conclusion:Findings of this cross‐sectional study suggest that COPD in males may be associated with severe periodontitis and indicates the importance of promoting dental care in patients with COPD.

We investigated the effects of particulate matter (PM) factors on hospitalization rates for asthma and chronic obstructive pulmonary disease (COPD).We obtained data on pollutants—PM10, PM2.5—in Seoul, South Korea. We also investigated data for asthma and COPD exacerbation that required hospitalization from 2006 to 2016. We used a time-stratified case-crossover design and generalized additive models with log transformation to assess adjusted risk, and conditional logistic regression was performed to analyze these data.Our study showed that PM10and PM2.5, on different best lag days, were associated with increased risks of COPD or asthma hospitalization. The odds ratios (ORs) for each per-unit increase in PM10and PM2.5were higher in patients with male asthma (PM10: OR, 1.012; 95% confidence interval [CI], 1.008–1.016 and PM2.5: OR, 1.015; 95% CI, 1008–1.023), preschool asthma (PM10: OR, 1.015; 95% CI, 1.006–1.015 and PM2.5: OR, 1.015; 95% CI, 1.009–1.024), male COPD (PM10: OR, 1.012; 95% CI, 1.005–1.019 and PM2.5: OR, 1.013; 95% CI, 1.000–1.026), and senior COPD (PM10: OR, 1.016; 95% CI, 1.008–1.024 and PM2.5: OR, 1.022; 95% CI, 1.007–1.036).Increasing PM levels increased hospitalizations for asthma and COPD. Additionally, the consequences may be different according to age and sex, and PM2.5may have a more significant effect on airway disease patients than PM10.

Objectives: To investigate the impact of olfactory dysfunction on quality of life (QOL) and psychological status in patients with chronic rhinosinusitis with nasal polyps (CRSwNP).Methods: A retrospective observational study was conducted from January 2011 to May 2012 with 130 patients with septal deviation (SD) (n = 59) and CRSwNP (n = 71). All patients underwent computed tomography (CT), allergy tests, and sniffin’ stick olfactory test. Anosmia was defined by Threshold-Discrimination-Identification (TDI) scores less than 16. QOL and psychological symptoms were assessed with the Sinonasal Outcome Test-20 (SNOT-20) and Symptom Checklist-90-Revised (SCL-90-R).Results: Odor discrimination and identification scores were significantly lower in CRSwNP than in SD (P= .008 and P= .005, respectively). In CRSwNP, identification score decreased with higher CT score (r= −0.29, P= .014). CRSwNP with anosmia showed a decreased QOL (P= .044), and SNOT-20 negatively correlated with TDI in severe CRSwNP (CT score ≥15, r= −0.714, P= .001). Anosmia patients had higher anxiety and phobia scores of SCL-90-R in both SD and CRSwNP. However, depression score increased only in CRSwNP with anosmia (P= .025).Conclusion: Olfactory dysfunction may have significant effects on QOL and psychological health. CRSwNP with anosmia is a distinct phenotype having mixed type of olfactory loss that might have a detrimental effect on depression.

Co-doped branched ZnO nanowires were prepared by multistep vapor-phase reactions for the ultraselective and sensitive detection of p-xylene. Highly crystalline ZnO NWs were transformed into CoO NWs by thermal evaporation of CoCl2powder at 700 °C. The Co-doped ZnO branches were grown subsequently by thermal evaporation of Zn metal powder at 500 °C using CoO NWs as catalyst. The response (resistance ratio) of the Co-doped branched ZnO NW network sensor to 5 ppm p-xylene at 400 °C was 19.55, which was significantly higher than those to 5 ppm toluene, C2H5OH, and other interference gases. The sensitive and selective detection of p-xylene, particularly distinguishing among benzene, toluene, and xylene with lower cross-responses to C2H5OH, can be attributed to the tuned catalytic activity of Co components, which induces preferential dissociation of p-xylene into more active species, as well as the increase of chemiresistive variation due to the abundant formation of Schottky barriers between the branches.

In this work, we report a dramatic enhancement in ethanol sensing characteristics of NiO hollow nanostructures via decoration with In2O3nanoclusters. The pure NiO and 1.64–4.41 atom % In-doped NiO and In2O3-decorated NiO hollow spheres were prepared by ultrasonic spray pyrolysis, and their gas sensing characteristics were investigated. The response (the ratio between the resistance in gas and air) of the In2O3-decorated NiO hollow spheres to 5 ppm ethanol (C2H5OH) was 9.76 at 350 °C, which represents a significant improvement over the In-doped NiO and pure NiO hollow spheres (3.37 and 2.18, respectively). Furthermore, the 90% recovery time was drastically reduced from 1880 to 23 s, and a selective detection of ethanol with negligible cross-response to other gases was achieved. The enhanced gas response and fast recovery kinetics were explained in relation to the thinning of the near-surface hole accumulation layer of p-type NiO underneath n-type In2O3, the change of charge carrier concentration, and the variation of oxygen adsorption.

To investigate adjuvant effect and safety of intratympanic steroid for the treatment of Bell’s palsy.

ABSTRACTPrevious reports have shown that the sensitivity of the 6-day lymphocyte stimulation test is much higher than those of commercially available gamma interferon release assays (IGRAs). The aim of this study was to elucidate the effect of prolonged incubation on the results of the QuantiFERON TB Gold in-tube (QFT-GIT) assay. Patients aged >20 years with suspected tuberculosis (TB) were recruited prospectively from 1 May 2009 to 31 December 2010. In addition, healthy volunteers with no history of TB treatment were included as controls. For each participant, three sets of the QFT-GIT assay were performed using 24-, 48-, and 72-h incubation tests, and the results were compared. Thirty-seven patients with suspected pulmonary TB and 33 healthy controls were enrolled in the study. Of the 37 patients with suspected TB, the QFT-GIT assay results were positive for 28 (75.7%) after a 24-h incubation period. After prolonged incubation, the results differed in four (10.8%) of the 37 patients suspected of having TB. Among 27 patients with culture-confirmed TB, the sensitivities of the QFT-GIT assay after the 24-, 48-, and 72-h incubation tests were 85.2%, 81.5%, and 81.5%, respectively. Among the 33 healthy controls, the QFT-GIT assay results were positive in two (6.1%) after a 24-h incubation period. The results changed for two (6.1%) of the 33 healthy controls after prolonged incubation. The specificities of the QFT-GIT assay after 24, 48, and 72 h of incubation were 93.9%, 87.9%, and 90.9%, respectively. Prolonging the incubation time did not increase the sensitivity of the QFT-GIT assay. The manufacturer-recommended incubation time of 16 to 24 h should be respected because prolonged incubation can cause indeterminate or false-positive results.

CdCr2O4is a cubic spinel with geometrically-frustrated antiferromagnetic interactions between Cr3+ions. We investigated the structural and magnetic phase transitions in powder samples by using magnetization and neutron diffraction measurements. An antiferromagnetic phase transition was observed at TN= 8.1 K, below which the crystallographic unit cell was tetragonal (c< a= b). Its incommensurate antiferromagnetic ordering below TNresembles dimerized spin chains in the abplanes with the propagation vector k= (0, 0.088, 1). We argue that the Dzyaloshinskii-Moriya interaction and the magnetic frustration play important roles in establishing the observed magnetic ordering.

Single-crystalline Mn3O4nanowires were prepared using the vapor-phase transformation of ZnO nanobelts. Mn3O4-decorated ZnO nanobelts and ZnO–ZnMn2O4core–shell nanocables (NCs) were also obtained as reaction intermediates. Heteroepitaxial growth of tetragonal spinel Mn3O4(or ZnMn2O4) on wurtzite ZnO is a possible reason for the growth of single-crystalline Mn3O4nanowires. Growth interfaces are possibly formed between the wurtzite (101̅0)/(21̅1̅0) and spinel (1̅01)/(4̅11) planes. Various one-dimensional homonanostructures and heteronanostructures consisting of n-ZnO, p-Mn3O4, and p-ZnMn2O4can be used to design high-performance gas sensors.

The spinel crystal system, AB2O4, has been fertile ground in studying the effects of magnetic and orbital frustration. The experimental findings, with primary focus on neutron and synchrotron x-ray scattering techniques, are hereby reviewed in spinels with magnetic B ions. Highlighted are novel collective phenomena, such as the zero-energy excitation mode in the spin liquid phase, zero-field and field-induced novel phase transitions, the emergence of complex local spin entities, and heavy fermionic behaviors. Such a diversity in the exotic properties stems from their close proximity to critical points among degenerate states and a delicate balance among different degrees of freedom such as spin, orbital, and lattice.

South Korea's mode of responding to the rise of China is not fixed but continues to evolve. The recent clash over Koguryo historiography provides a sobering example of how easily the symbiotic relationship can be abruptly interrupted. It shows the need for careful management of the bilateral relationship by both Seoul and Beijing.

A series of cyclic silylene-bridged (amidocyclopentadienyl)dichlorotitanium(IV) complexes [TiCl2{η5-1-(CySitBuN-κN)-2,3,4,5-R4-C5}] was prepared, where CySi = silacyclobutyl (a), silacyclopentenyl (b), silacyclopentyl (c), and silacyclohexyl (d); R = H (4), Me (5). The starting silane, dichlorosilacycloalkane CySiCl2(1), was treated with NaCp (LiCp*), followed by LiNHtBu to yield the cyclic silylene-bridged ligands (R4C5)CySi(NHtBu) [R = H (2); Me (3)]. Subsequent deprotonation with n-butyllithium, followed by transmetalation with TiCl4yielded the desired constrained geometry complexes (CGCs) (CpCySiNtBu)TiCl2(4) and (Cp*CySiNtBu)TiCl2(5). The structures of the resulting cyclopentadienyl- (4band 4c) and tetramethylcyclopentadienyl(silacycloalkyl)amidotitanium(IV) dichloride (5a, 5c, and 5d) species were studied by using X-ray crystallography to obtain geometrical information on cyclic silylene-modified CGCs. The ethylene polymerization by the cyclic silylene-bridged CGCs 4and 5was examined to verify the structure–catalytic activity relationship derived from variation of the size of a cyclic silylene ring. Indeed, the size of the cyclic silylene ring at the 1,1′-position of 4and 5affected the catalytic activities through the ethylene polymerization. Systematic increase in the catalytic activities was observed as the cyclic silylene-bridging unit was expanded from a four- to six-membered ring. In the present study, we found that CGCs of TiIVwith a six-membered silylene-bridged ligand (5d) produced active catalytic species for the formation of polyethylene with Mw= 42.7 × 10–4g mol–1and Mw/Mn= 2.1 with excellent catalytic activities (20.9 kg polymer per mmol of Ti). When titanium(IV) dimethyl complex (6d) was applied in continuous polymerization process, impressive high catalytic activity on copolymerization with 1-octene was observed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

There have been two measurement methods for nasal nitric oxide (nNO): direct measurement of nNO and indirect measurement of NO metabolites or the NO synthase enzyme. The aim of this study is to investigate the difference in nNO between allergic rhinitis (AR) patients and the correlation of the direct measurement of nNO and indirect measurement of nNO metabolites, RANTES, and IL-5. Fifteen patients with AR, 15 patients with septal deviation as a control group were enrolled. We measured the nNO level using a chemiluminescence analyzer and the amount of NO metabolites, RANTES, and IL-5 in nasal lavage fluid using the ELISA method. Nasal NO levels were significantly higher in AR than the control (195.7 ± 39.6 vs 159.4 ± 25.8 ppb, P= 0.027). NO metabolites, IL-5, and RANTES levels were higher in AR, but there was no statistically significant difference. There was no significant correlation between nNO and nNO metabolites, RANTES, IL-5, and clinical parameters except for the olfactory test score in AR. There was a negative correlation between nNO and the olfactory test score in AR (r= −0.590, P= 0.034). Nasal NO concentration increased in AR. However, nNO metabolites and IL-5, RANTES in nasal secretion did not show any correlation with nNO. Direct measurement of nNO could be a potentially useful biomarker of AR compared to indirect measurement of NO metabolites, cytokines, and chemokines in nasal secretion.

Tin dioxide thin films were prepared by dual ion beam sputtering on various substrates. The Sn and the SnO2targets were sputtered with 1000 eV, 1.5–2.0 mA/cm2argon ion beam, and the water-cooled substrates were simultaneously bombarded with oxygen ion beam of 0–200 eV and 200 μA/cm2. All of oxygen-assisted thin films showed high transparency and bulk-like refractive indices, while the sputtered film without bombardment had relatively poor transmittance. As the bombarding energy increased, the absorption edge shifted to lower wavelength and the optical band gap energy increased to a maximum value of 4.21 eV. Four-point-probe measurement showed that the resistivity of as-deposited films depended strongly on target material and bombardment energy. After heat treatment, the optical band gap and the resistivity showed similar behavior and had their maxima after annealing at 400°C.

One of the most explicit manifestations of post-Mao China’s pragmatic foreign policy has been the significant shift in Beijing’s position vis-à-vis Seoul from a “non-policy” todefactoeconomic diplomacy. Despite the extent of cooperative endeavors, Sino-South Korean economic relations have been circumscribed by various domestic and external factors. While a further intensification of the cooperative relationship is projected for the second decade of Sino-South Korean economic diplomacy, the actual materialization of such prospects depends on how China and South Korea are going to maintain economic complementarity. More importantly, it also depends on when and how China is going to accommodate politically its economic relations with South Korea by resolving the issue of “two Koreas,” thus maximizing the potential benefits from its ties with Seoul and simultaneously minimizing the negative effects from the entanglements of various domestic and foreign factors.