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To determine the level of vitamin D and to identify the association between vitamin D and depressive symptoms in apparently healthy Korean male adults.
A retrospective study design. Among 43 513 participants between 1 March and 30 November 2018, after eliminating participants with a history of depression or vitamin D deficiency, 9058 were included. To determine the level of vitamin D, serum 25-hydroxyvitamin D [25(OH)D] was measured. To assess the level of depression, the Korean version of the Center for Epidemiologic Studies Depression Scale (CES-D) was used.
Male adults who underwent routine health check-ups.
The average vitamin D level was 22·31 ± 7·09 ng/ml as 25(OH)D, while the number of subjects in the vitamin D insufficiency group with a finding of <20 ng/ml was 3783 (41·8 %). The mean CES-D score in all subjects was 8·31 ± 5·97 points, and the proportion of the depressive symptoms group with a score of ≥16 was 8·71 %. The OR of patients in the depressive symptoms group also being in the insufficiency group was found to be 1·49 (95 % CI 1·12, 2·00).
A total of 41·8 % of apparently healthy male adults had vitamin D levels <20 ng/ml. We identified an association between vitamin D insufficiency and depressive symptoms in apparently healthy Korean male adults.
The aim of this study was to model the relationships among white matter hyperintensities (WMHs), depressive symptoms, and cognitive function and to examine the mediating effect of depressive symptoms on the relationship between WMHs and cognitive impairment.
We performed structural equation modeling using cross-sectional data from 1158 patients from the Clinical Research for Dementia of South Korea (CREDOS) registry who were diagnosed with mild-to-moderate dementia. Periventricular white matter hyperintensities (PWMHs) and deep white matter hyperintensities (DWMHs) were obtained separately on the protocol of magnetic resonance imaging (MRI). Depression and cognitive function were assessed using the Korean Form of the Geriatric Depression Scale (KGDS) and the Seoul Neuropsychological Screening Battery (SNSB), respectively.
The model that best reflected the relationships among the variables was the model in which DWMHs affected cognitive function directly and indirectly through the depressive symptoms; on the other hand, PWMHs only directly affected cognitive function.
This study presents the mediation model including the developmental pathway from DWMHs to cognitive impairment through depressive symptoms and suggests that the two types of WMHs may affect cognitive impairment through different pathways.
Despite the possibility that cognitive deficits associated with depression may have different patterns depending on the level of neurocognitive impairment, there remains no clear evidence of this. This study aimed to investigate the differential association between depression and cognitive function in patients with mild cognitive impairment (MCI) and Alzheimer’s disease (AD).
A cross-sectional analysis was performed of data from 1,724 patients with MCI and 1,247 patients with AD from the Clinical Research Center for Dementia in Korea. Depression was assessed using the Korean form of the Geriatric Depression Scale, and cognition was measured using the Seoul Neuropsychological Screening Battery, which includes five domains (attention, language and related function, visuospatial function, memory, and frontal/executive function).
Significant differences were found between the two groups (non-depressed vs. depressed) in visuospatial, memory, and executive function domains in the MCI group, as well as in the attention domain in the AD group. The association between depressive symptoms and cognitive function was significantly greater in patients with MCI than in those with AD. These associations were more pronounced in memory and executive function.
Our findings suggest that the association between depression and decreased cognitive function is more pronounced in MCI than AD.
Dense ZrB2–SiC nanocomposites were fabricated at 1450 °C by the high-energy ball milling (HEBM) of ZrB2 powder with ZrSi2–B4C–C additives and reactive spark plasma sintering (R-SPS). The sizes of ZrB2 and SiC grains were 80–350 nm, and the phases were homogeneously distributed because of the molecular-level homogeneity of the constituents in ZrSi2 and the homogeneous mixing of the raw powders by HEBM. The deformation of ZrSi2 or the reactions between the additives during R-SPS did not strongly promote the densification. Fine and homogeneously distributed ZrB2 and SiC particles formed by HEBM and R-SPS were the major reasons for the low temperature densification. The fine particles which had high surface energy provided the driving force for densification at low temperatures. Also, the fine SiC grains suppressed the growth of ZrB2 grains during densification. The 4-point bending strength of the composites sintered at 1500 °C was 354 MPa.
The Sewol ferry disaster is one of the most tragic events in Korea’s modern history. Among the 476 people on board, which included Danwon High School students (324) and teachers (14), 304 passengers died in the disaster (295 recovered corpses and 9 missing) and 172 survived. Of the rescued survivors, 72 were attending Danwon High School, located in Ansan City, and residing in a residence nearby. Because the students were young, emotionally susceptible adolescents, both the government and the parents requested the students be grouped together at a single hospital capable of appropriate psychiatric care. Korea University Ansan Hospital was the logical choice, as the only third-tier university-grade hospital with the necessary faculty and facilities within the residential area of the families of the students. We report the experiences and the lessons learned from the processes of preparing for and managing the surviving young students as a community-based hospital. (Disaster Med Public Health Preparedness. 2017;11:389–393)
The thickness dependence of the electrical stability under monotonic and cyclic tensile loading is investigated for Cu films on polymer substrates. As for monotonic tensile deformation, thicker films show better stability than thinner films due to their higher ductility and the larger capability of strain accommodation. For the fatigue resistance, however, a more complex behavior was observed depending on the amount of the applied strain. For low strain amplitude in the high cycle fatigue (HCF) regime, thinner films exhibit longer fatigue life because the larger strength of thinner films suppresses dislocation movement and damage nucleation. However, for high strain amplitudes in the low cycle fatigue (LCF) regime, the fatigue life for thinner films is drastically reduced compared to thicker films. It is shown that fatigue coefficients in the LCF regime can be obtained when applying the Coffin–Manson relationship.
To describe the incidence of recovery of both vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) from culture of a single clinical specimen, to describe the clinical characteristics of patients from whom these specimens were recovered, and to identify the risk factors of these patients.
A retrospective cohort and case-control study.
A tertiary care university hospital and referral center in Seoul, Korea.
We identified 61 case patients for whom a single clinical specimen yielded both VRE and MRSA on culture, and 122 control patients for whom any clinical specimen yielded only VRE on culture. The control patients were selected by matching 2 :1 with the case patients for age, sex, and first date of sampling that led to isolation of VRE or both VRE and MRSA among 1,536 VRE-colonized patients from January 1, 2003, through December 31, 2006. To identify patient risk factors for the recovery of both VRE and MRSA in a single clinical specimen, we performed univariate comparisons between the 2 groups and then multivariate logistic regression analysis.
The incidence of recovery of both VRE and MRSA from culture of a single clinical specimen was 3.97% (for 61 of 1,536 VRE-colonized patients) over 4 years. Among these 82 single clinical specimens, the most common type was wound specimens (26.8%), followed by lower respiratory tract specimens (18.3%), urine specimens (17.1%), and catheter tips (15.9%). Of the 61 case patients, 14 (23.0%) had 2 or more single clinical specimens that yielded both VRE and MRSA on culture, and the longest interval from the first sampling that yielded both organisms to the last sampling that yielded both was 174 days. Independent patient risk factors for the presence of both VRE and MRSA in a single clinical specimen were chronic renal disease (odds ratio [OR], 7.00; P = .012), urinary catheterization (OR, 3.36; P = .026), and longer total cumulative duration of hospital stay within the previous year (OR, 1.03; P < .001).
We confirmed that the recovery of VRE and MRSA from a single clinical specimen occurs continually. Because prolonged cell-to-cell contact can facilitate transfer of vanA, close observation and surveillance for vancomycin-resistant S. aureus, especially among patients with risk factors for the recovery of both VRE and MRSA from a single clinical specimen, should be continued.
We investigate boron transient enhanced diffusion (TED) and series resistance in SiGe/Si heterojunction channel pMOSFET. The stress gradient at the SiGe/Si interface near the gate edge in high Ge concentrations are found to determine boron TED as well as extension junction shape, which has a significant impact on the parasitic LDD and source/drain (S/D) series resistance. In addition, high Ge concentrations in the epitaxial SiGe layer on top of Si substrate result in a high sheet resistance during a 1000°C/5s rapid thermal processing (RTP), which is mainly due to alloy scattering and interface roughness scattering.
CMP(Chemical Mechanical Planarization) process is widely used to reduce step height in semiconductor fabrication processes. As a design rule shrinks, a highly planar surface becomes inevitable within wafer scales. In order to get a high degree of a planarization, self-stopping characteristics of a ceria-based slurry should be studied and used in semiconductor process. In this study, threshold polishing pressure for a self-stopping characteristics was obtained by optimizing down pressure, pad conditioning, and mixing ratio of ceria abrasive and additive. A series of experiments were made to optimize the threshold polishing pressure in variable line & space patterns that consist of 0.8um step height and unit oxide film. As a result, self-stopping cmp process is twice batter than conventional silica-based process with respect to planarity and WIWNU. In addition, WIWNU and step height was dramatically decreased to less than 1000Å when applying to real fabrication devices over 2um step height.
Assessment of nuclear status is important when a biopsied single blastomere is used for embryo sexing. In this study we investigated the nuclear status of blastomeres derived from 8- to 16-cell stage in vitro fertilised bovine embryos to determine the representativeness of a single blastomere for embryo sexing. In 24 embryos analysed, the agreement in sex determination between a biopsied single blastomere and a matched blastocyst by polymerase chain reaction (PCR) was 83.3%. To clarify the discrepancies, karyotypes of blastomeres in 8- to 16-cell stage bovine embryos were analysed. We applied vinblastine sulfate at various concentrations and for different exposure times for metaphase plate induction in 8- to 16-cell stage bovine embryos. The 1.0 mg/ml vinblastine sulfate treatment for 15 h was selected as the most effective condition for induction of a metaphase plate (>45%). Among 22 embryos under these conditions, only 8 of 10 that had a normal diploid chromosome complement showed a sex chromosomal composition of XX or XY (36.4%) and 2 diploid embryos showed mosaicism of the opposite sex of XX and XY in blastomeres of the embryo (9.1%). One haploid embryo contained only one X-chromosome (4.5%). Four of another 11 embryos with a mixoploid chromosomal complement contained a haploid blastomere with a wrong sex chromosome (18.2%). In conclusion, assessment of nuclear status of 8- to 16-cell stage bovine embryos revealed that morphologically normal embryos had a considerable proportion of mixoploid blastomeres and sex chromosomal mosaicism; these could be the cause of discrepancies in the sex between biopsied single blastomeres and matched blastocysts by PCR.
White light-emitting devices were fabricated using the blends of blue, green, red emissive polymers of poly[9,9-(2'-ethylhexyl)fluorene] (PEHF), poly(9,9-dioctylfluorene-2,7-vinylene) (POFV), poly(2-(3',7'-dimethyloctyloxy)-5-methoxy-1,4-phenylene-1-cyanovinylene) (CNPPV) and poly(2-(2'-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene) (MEH-PPV). Inefficient energy transfers between the blue polymer and the green or the red polymer, which was observed in PL spectra of the blend films, provides a good opportunity to get white light emission due to better blend ratio controllability. The EL devices were fabricated with ITO/PEDOT/blend/Ca/Al configuration and good white light-emission was obtained for a certain blend ratio. The light-emission was observable from 4V and a maximum brightness of 400 cd/m2 was obtained with the device.
An alkoxyphenyl substitutued new polyfluorene derivative, poly(9,9-bis(4'-n-octyloxyphenyl) fluorene) (PBOPF) was synthesized through Ni(0) mediated polymerization. Blue light-emitting PBOPF shows peak PL at 426 nm. No significant excimer emission was observed even after annealing the polymer film at 100 oC for 2h. Aseries of random copolymers of 2,7-dibromo-9,9-bis(4'-n-octyloxyphenyl)) fluorene (BOPF) and 2,7-dibromo-N-(2'-ethylhexyl)carbazole (EHC) were also synthesized through Ni(0) mediated polymerization. Carbazole comonomer was introduced to improve hole-transporting properties of PBOPF. The synthesized poly(BOPF-co-EHC)s showed similar UV-visible absorption and PL emission to PBOPF. EL devices were fabricated in an ITO/PEDOT/polymer/Ca/Al configuration. The EL devices using copolymers showed improved device performance than the device using PBOPF homopolymer due to a more balanced charge transport.
Lead magnesium niobate–lead titanate [Pb(Mg1/3Nb2/3)O3 (PMN)–PbTiO3 (PT)] films were synthesized using pulsed laser deposition, and the effect of substrates on the deposition behavior of the PMN–PT film was investigated. Phase evolution of PMN–PT thin films was found to depend significantly on the type of the substrate used during deposition. Though a mixture of pyrochlore and perovskite was observed when films were deposited on a Pt/TiO2/SiO2/Si substrate, the oxide substrates, such as (Ba0.5Sr0.5)RuO3/Si, SrTiO3, and LaAlO3, enabled the deposition of pure perovskite. Scanning Auger microprobe, transmission electron microscope, and x-ray diffraction analysis showed that an interfacial layer between the substrates and the oxide film was central to the phase evolution behavior. On the Pt/TiO2/SiO2/Si substrate, an interfacial layer of lead–platinum (Pb–Pt) played a major role in the formation of the pyrochlore phase. However, on oxide substrates, there was no interfacial layer and interdiffusion of A-site cations was observed between the PMN film and the oxide electrodes.
Comprehensive measurements of electron spin resonance and magnetization of La0.7Ca0.3MnO3 in the ferromagnetic as well as paramagnetic phases were carried out. From the quantitative analysis of the ESR signal, attributed to itinerant spins and localized spins in the bottleneck regime, evidences for the inhomogeneous nature of both phases, consisting of clusters of one phase embedded in the other, were found. It is suggested that the microscopic local magnetic structures above and below Tc are qualitatively similar except that the phase below Tc carries long range order.
In this paper, we introduce a method to represent phrase structure
grammars for building a
large annotated corpus of Korean syntactic trees. Korean is different from
English in word
order and word compositions. As a result of our study, it turned out that
the differences are
significant enough to induce meaningful changes in the tree annotation
scheme for Korean
with respect to the schemes for English. A tree annotation scheme defines
formalism to be assumed, categories to be used, and rules to determine
correct parses for
unsettled issues in parse construction. Korean is partially free in word
order and the essential
components such as subjects and objects of a sentence can be omitted with
than in English. We propose a restricted representation of phrase structure
grammar to handle
the characteristics of Korean more efficiently. The proposed representation
is shown by means
of an extensive experiment to gain improvements in parsing time as well
as grammar size.
We also describe the system named Teb that is a software environment set
up with a goal to
build a tree annotated corpus of Korean containing more than one million
An amorphized tungsten nitride diffusion barrier is compared with that of polycrystalline tungsten nitride preventing the diffusion of copper into Si during post annealing processes at 600 – 800 °C for 30 min. Experimental evidence such as RBS, TEM, XRD measurements shows that the amorphized tungsten nitride layer perfectly blocks the expeditious diffusion of the Cu film due to the amorphous grain boundaries stuffed with N impurities.
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