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To evaluate the impact of a vancomycin-resistant Enterococcus (VRE) screening policy change on the incidence of healthcare-associated (HA)-VRE bacteremia in an endemic hospital setting.
A quasi-experimental before-and-after study.
A 1,989-bed tertiary-care referral center in Seoul, Republic of Korea.
Since May 2010, our hospital has diminished VRE screening for admitted patients transferred from other healthcare facilities. We assessed the impact of this policy change on the incidence of HA-VRE bacteremia using segmented autoregression analysis of interrupted time series from January 2006 to December 2014 at the hospital and unit levels. In addition, we compared the molecular characteristics of VRE blood isolates collected before and after the screening policy change using multilocus sequence typing and pulsed-field gel electrophoresis.
After the VRE screening policy change, the incidence of hospital-wide HA-VRE bacteremia increased, although no significant changes of level or slope were observed. In addition, a significant slope change in the incidence of HA-VRE bacteremia (change in slope, 0.007; 95% CI, 0.001–0.013; P = .02) was observed in the hemato-oncology department. Molecular analysis revealed that various VRE sequence types appeared after the policy change and that clonally related strains became more predominant (increasing from 26.1% to 59.3%).
The incidence of HA-VRE bacteremia increased significantly after VRE screening policy change, and this increase was mainly driven by high-risk patient populations. When planning VRE control programs in hospitals, different approaches that consider risk for severe VRE infection in patients may be required.
Network approach has been applied to a wide variety of psychiatric disorders. The aim of the present study was to identify network structures of remitters and non-remitters in patients with first-episode psychosis (FEP) at baseline and the 6-month follow-up.
Participants (n = 252) from the Korean Early Psychosis Study (KEPS) were enrolled. They were classified as remitters or non-remitters using Andreasen's criteria. We estimated network structure with 10 symptoms (three symptoms from the Positive and Negative Syndrome Scale, one depressive symptom, and six symptoms related to schema and rumination) as nodes using a Gaussian graphical model. Global and local network metrics were compared within and between the networks over time.
Global network metrics did not differ between the remitters and non-remitters at baseline or 6 months. However, the network structure and nodal strengths associated with positive-self and positive-others scores changed significantly in the remitters over time. Unique central symptoms for remitters and non-remitters were cognitive brooding and negative-self, respectively. The correlation stability coefficients for nodal strength were within the acceptable range.
Our findings indicate that network structure and some nodal strengths were more flexible in remitters. Negative-self could be an important target for therapeutic intervention.
Background: After the Middle East respiratory syndrome coronavirus outbreak in Korea in 2015, the government newly established the additional reimbursement for infection prevention to encourage infection control activities in the hospitals. The new policy was announced in December 2015 and was implemented in September 2016. We evaluated how infection control activities improved in hospitals after the change of government policy in Korea. Methods: Three cross-sectional surveys using the WHO Hand Hygiene Self-Assessment Framework (HHSAF) were conducted in 2013, 2015, and 2017. Using multivariable linear regression model including hospital characteristics, we analyzed the changes in total HHSAF scores according to the survey time. Results: In total, 32 hospitals participated in the survey in 2013, 52 in 2015, and 101 in 2017. The number of inpatient beds per infection control professionals decreased from 324 in 2013 to 303 in 2015 and 179 in 2017. Most hospitals were at intermediate or advanced levels of progress (90.6% in 2013, 86.6% in 2015, and 94.1% in 2017). In a multivariable linear regression model, the total HHSAF scores were significantly associated with hospital teaching status (β coefficient of major teaching hospital, 52.6; 95% CI, 8.9–96.4; P = .018), bed size (β coefficient of 100-bed increase, 5.1; 95% CI, 0.3–9.8; P = .038), and survey time (β coefficient of 2017 survey, 45.1; 95% CI, 19.3–70.9; P = .001). Conclusions: After the national policy implementation, the number of infection control professionals increased, and the promotion of hand hygiene activities was strengthened in Korean hospitals.
This study aimed to investigate associations among spirituality, coping strategies, quality of life (QOL), and the effects of depression and anxiety thereon in cancer patients.
In total, 237 cancer patients referred to a psycho-oncology clinic at a university hospital in Korea were enrolled. After identifying predictors of patient QOL in a stepwise regression model, we developed a hypothetical path model wherein interpersonal coping was considered as a mediating variable between spirituality (meaning/peace) and QOL and wherein depression and anxiety affected each of these three variables.
The direct effect of spirituality (meaning/peace) on QOL was 36.7%. In an indirect model, interpersonal coping significantly mediated the relationship between spirituality (meaning/peace) and QOL. Depression exerted the largest negative effect on spirituality (meaning/peace), interpersonal coping, and QOL. Anxiety had negative effects on spirituality (meaning/peace) and QOL, but a positive effect on interpersonal coping.
Significance of results
Interpersonal coping strategies work as a partial mediator of the relationship between meaning/peace subscales of spirituality and QOL. Effective management of depression may help in achieving better outcomes associated therewith. Greater attention and efforts to improve social connectedness and meaning of life in spiritual well-being may improve the QOL of cancer patients.
Our objective was to evaluate long-term altered appearance, distress, and body image in posttreatment breast cancer patients and compare them with those of patients undergoing active treatment and with general population controls.
We conducted a cross-sectional survey between May and December of 2010. We studied 138 breast cancer patients undergoing active treatment and 128 posttreatment patients from 23 Korean hospitals and 315 age- and area-matched subjects drawn from the general population. Breast, hair, and skin changes, distress, and body image were assessed using visual analogue scales and the EORTC BR–23. Average levels of distress were compared across groups, and linear regression was utilized to identify the factors associated with body image.
Compared to active-treatment patients, posttreatment patients reported similar breast changes (6.6 vs. 6.2), hair loss (7.7 vs. 6.7), and skin changes (5.8 vs. 5.4), and both groups had significantly more severe changes than those of the general population controls (p < 0.01). For a similar level of altered appearance, however, breast cancer patients experienced significantly higher levels of distress than the general population. In multivariate analysis, patients with high altered appearance distress reported significantly poorer body image (–20.7, CI95% = –28.3 to –13.1) than patients with low distress.
Significance of results:
Posttreatment breast cancer patients experienced similar levels of altered appearance, distress, and body-image disturbance relative to patients undergoing active treatment but significantly higher distress and poorer body image than members of the general population. Healthcare professionals should acknowledge the possible long-term effects of altered appearance among breast cancer survivors and help them to manage the associated distress and psychological consequences.
Recently there has been great progress in laser-driven plasma-based accelerators by exploiting high-power lasers, where electron beams can be accelerated to multi-GeV energy in a centimeter-scale plasma due to the laser wakefield acceleration mechanism. While, to date, worldwide research on laser plasma accelerators has been focused on the creation of compact particle and radiation sources for basic sciences, medical and industrial applications, there is great interest in applications for high-energy physics and astrophysics, exploring unprecedented high-energy frontier phenomena. In this context, we present an overview of experimental achievements in laser plasma acceleration from the perspective of the production of GeV-level electron beams, and deduce the scaling formulas capable of predicting experimental results self-consistently, taking into account the propagation of a relativistic laser pulse through plasma and the accelerating field reduction due to beam loading. Finally, we present design examples for 10-GeV-level laser plasma acceleration, which is expected in near-term experiments by means of petawatt-class lasers.
Distribution of wax in laser printer toner was observed using an ultra-high-voltage (UHV) and a medium-voltage transmission electron microscope (TEM). As the radius of the wax spans a hundred to greater than a thousand nanometers, its three-dimensional recognition via TEM requires large depth of focus (DOF) for a volumetric specimen. A tomogram with a series of the captured images would allow the determination of their spatial distribution. In this study, bright-field (BF) images acquired with UHV-TEM at a high tilt angle prevented the construction of the tomogram. Conversely, the Z-contrast images acquired by the medium-voltage TEM produced a successful tomogram. The spatial resolution for both is discussed, illustrating that the image degradation was primarily caused by beam divergence of the Z-contrast image and the combination of DOF and chromatic aberration of the BF image from the UHV-TEM.
Pb is released from bone stores during pregnancy, which constitutes a period of increased bone resorption. A high Na intake has been found to be negatively associated with Ca and adversely associated with bone metabolism. It is possible that a high Na intake during pregnancy increases the blood Pb concentration; however, no previous study has reported on the relationship between Na intake and blood Pb concentration. We thus have investigated this relationship between Na intake and blood Pb concentrations, and examined whether this relationship differs with Ca intake in pregnant Korean women. Blood Pb concentrations were analysed in 1090 pregnant women at mid-pregnancy. Dietary intakes during mid-pregnancy were estimated by a 24 h recall method covering the use of dietary supplements. Blood Pb concentrations in whole-blood samples were analysed using graphite furnace atomic absorption spectrophotometry. Multiple regression analysis performed after adjustment for covariates revealed that maternal Na intake was positively associated with blood Pb concentration during pregnancy, but only when Ca intake was below the estimated average requirement for pregnant Korean women (P= 0·001). The findings of the present study suggest that blood Pb concentration during pregnancy could be minimised by dietary recommendations that include decreased Na and increased Ca intakes.
We investigated the pressure dependence of the inductive coupled plasma (ICP) oxidation on the electrical characteristics of the thin oxide films. Activation energies and electron temperatures with different pressures were estimated. To demonstrate the pressure effect on the plasma oxide quality, simple N type metal-oxide-semiconductor (NMOS) transistors were fabricated and investigated in a few electrical properties. At higher pressure than 200mTorr, plasma oxide has a slightly higher on-current and a lower interfacial trap density. The on-current gain seems to be related to the field mobility increase and the lower defective interface to the electron temperature during oxidation.
This study investigated the associations among vitamin D receptor (VDR) BsmI polymorphism, calcium intake and bone strength as indicated by the broadband ultrasound attenuation (BUA) measured by calcaneal quantitative ultrasound at the left calcaneus in community-dwelling subjects with a low calcium intake. The VDR BsmI polymorphism was analysed in 335 women older than 65 years residing in rural Asan, Korea. Calcium intake was assessed with a 2 d, 24 h recall method. The distribution of genotypes was similar to that reported in other Asian populations (92 % bb, 7 % Bb and 1 % BB). The calcaneal BUA was significantly higher (P = 0·013) in the bb genotype than in the Bb or BB genotype (Bb and BB genotypes were combined due to the small number of BB subjects) in a multiple regression model after adjusting for age, body weight, height, physical activity and nutritional factors. BUA was not significantly affected by the calcium intake regardless of the genotype, cross-sectionally. The energy-adjusted average calcium intake of this population was 439·6 mg/d (432·5 mg/d for bb and 522·3 mg/d for Bb or BB), and 96 % of the subjects had dietary intakes that were less than the recommended Dietary Reference Intake for Koreans (which for calcium is 800 mg/d for women older than 65 years). In summary, the BUA in older Korean women with a low calcium intake was significantly influenced by the VDR genotype but not by the calcium intake, cross-sectionally.
To determine the appropriateness of antibiotic prophylaxis regimens for major surgery in Korea.
Retrospective study using a written survey for each patient who underwent arthroplasty, colon surgery, or hysterectomy.
Six tertiary hospitals in Seoul and Gyeonggi Province.
From each hospital, a maximum of 150 patients who underwent each type of surgery were randomly chosen for the study.
Of 2,644 eligible patients, 1,914 patients were included in the analysis; 677 of these patients underwent arthroplasty, 578 underwent colon surgery, and 659 underwent hysterectomy. Nineteen patients were excluded from the analyses of the class and number of antibiotics used for prophylaxis because they underwent multiple surgeries at different sites. For each of the 1,895 remaining patients, antibiotic prophylaxis involved a mean ( ± SD) of 2.8 ± 0.9 classes of antibiotics. The most commonly prescribed agents were cephalosporins (prescribed for 1,875 [98.9%] of the patients) and aminoglycosides (1,404 [74.1%]). A total of 1,574 (83.1%) of patients received at least 2 classes of antibiotics simultaneously. Only 15 (0.8%) of 1,895 patients received antibiotic prophylaxis in accordance with published guidelines. Of 506 patients for whom the initial dose of antibiotics was evaluated, 374 (73.9%) received an appropriate initial dose. Of the 1,676 patients whose medical records included information about antibiotic administration relative to the time of surgery, only 188 (11.2%) received antibiotic prophylaxis an hour or less before the surgical incision was made. Of the 1,748 patients whose medical records included information about duration of surgery, antibiotic prophylaxis was discontinued 24 hours or less after surgery for only 3 (0.2%) of the patients.
Most patients who had major surgery in Korea received inappropriate antibiotic prophylaxis. Measures to improve the appropriateness of antibiotic prophylaxis are urgently required.
The thermal degradation behavior of indium tin oxide (ITO) thin films coated on glass substrates using radio frequency (rf) magnetron sputtering was investigated over the temperature range of 100–400 °C in air. The resistivity of ITO films increases abruptly after the thermal degradation temperature of 250 °C is reached, with a slight increase from 200 to 250 °C. The x-ray photoelectron spectrometry intensity ratio of O/(In + Sn) in thermally degraded ITO films is higher than that in normal films. The carrier concentration gradually decreases up to 200 °C, sharply drops between 200 and 250 °C with increasing temperature, and then saturates from 275 °C. The Hall mobility drops suddenly at 275 °C. The diffusion of oxygen into oxygen interstitials and oxygen vacancies and the chemisorption of oxygen into grain boundaries decrease the carrier concentration and the Hall mobility, respectively. The former mainly affects the resistivity of ITO films below 250 °C, and the later above 250 °C.
NiCr films were thermally evaporated on the Mn-Ni-Co-O thick-film substrates. The NiCr/Mn-Ni-Co-O bi-layer systems were tested in a thermal shock chamber with three temperature differences of 150, 175 and 200°C. The systems were considered to have failed when the sheet resistance of NiCr films changed by 30% relative to an initial value. As the cyclic repetition of thermal shock increased, the sheet resistance of NiCr coatings increased. The Coffin-Manson equation was applied to the failure mechanism of cracking of NiCr coatings and the SEM observation of cracks and delamination in NiCr coatings due to thermal cycling agreed well with the failure mechanism.
Dielectric ceramics in the system (Zn1−xNix)TiO3, x = 0 to 1 were synthesized by the solid-state reaction route. The phase distribution, microstructure, and dielectric properties were characterized using powder x-ray diffraction analysis, electron microscopy, and microwave measurement techniques. Three phase composition regions were identified in the specimens sintered at 1150 °C: [spinel + rutile] at 0 ≤ x ≤ 0.5, [spinel + ilmenite + rutile] at 0.5 < x ≤ 0.8, and [ilmenite] phase at 0.8 < x ≤ 1. For the 0 ≤ x ≤ 0.5 region, the amount of Ti-rich precipitates incorporated into the spinel phase decreased with the Ni content at 0 ≤ x ≤ 0.5, with a concomitant increase of the rutile phase. The microwave dielectric properties depended on the phase composition and volume according to the three typical phase regions, where the relative amount of rutile to the spinel or ilmenite determined the dielectric properties. The dielectric constant as a function of Ni addition was modeled with a Maxwell mixing rule. An optimum phase distribution was determined in this system with dielectric constant of 22, a Q × f of 60,000, and a low temperature coefficient of the resonant frequency.
Large area, flat panel detectors are being investigated for digital radiogrpahy and fluoroscopy. Theses detectors employ an x-ray conversion layer of photoconductor to detect x-rays. The amorphous selenium layer that is currently being studied for its use as an x-ray photoconductor is not pure a-Se but rather a-Se doped with 0.2-0.5% As and 10-30 ppm Cl, also known as stabilized a-Se. The suitability of the stabilized a-Se is largely determined by its charge on generating, transporting and trapping properties.
In this paper, a conventional time-of-flight measurement was carried out to analyze the transport properties of charge carriers. A laser beam with pulse duration of 5 ns and wavelength of 350 nm was illuminated on the surface of the stabilized a-Se with thickness of 400 μm. The photo response signals of the hole and electron were measured at the applied electric field of 10 V/μm as a function of time. The measured transit times of the hole and electron were about 229.17μs and about 8.73μs at 10 V/μm, respectively. The measured mobility indicated a slight dependence with respect to the applied electric field with a range of 4-10 V/μm. The experimental results showed that the measured mobility of the hole and electron was 0.04584 cm2V-1s-1 and 0.00174 cm2V-1s-1 at the electric field of 10 V/μm.
For a diffusion barrier against Cu, tantalum nitride (TaN) films have been successfully deposited by both conventional thermal atomic layer deposition (ALD) and plasma assisted atomic layer deposition (PAALD), using pentakis (ethylmethlyamino) tantalum (PEMAT) and ammonia (NH3) as precursors. The growth rate of PAALD TaN at substrate temperature 250° was slightly higher than that of ALD TaN (0.80 Å/cycle for PAALD and 0.75 Å/cycle for ALD). Density of TaN films deposited by PAALD was as high as 11.0 g/cm3, considerably higher compared to the value of 8.3 g/cm3 obtained by ALD. The N: Ta ratio for ALD TaN was 44: 37 in composition and the film contained approximately 8∼10 atomic % carbon and 11 atomic % oxygen impurities. On the other hand, the ratio for PAALD TaN layers was 47: 44 and the respective carbon and oxygen contents of TaN layers decreased to 3 atomic % and 4 atomic %. The stability of 10 nm-thick TaN films as a Cu diffusion barrier was tested through thermal annealing for 30 minutes in N2 ambient and characterized by XRD, which proves the PAALD deposited TaN film to maintain better barrier properties against Cu below 800°.
To identify antibiotic resistance trends and risk factors for resistance of Serratia species to third-generation cephalosporins.
Retrospective survey of medical records.
A 2,200-bed, tertiary-care hospital.
One hundred twenty-two patients with Serratia bacteremia between January 1991 and June 2001.
Infectious disease physicians collected data from medical records regarding patient demographics, underlying disease or condition, portal of entry, microorganism, antibiogram, complications, antibiotics received, and outcome.
Among 122 Serratia isolates, 117 (95.9%) were Serratia marcescens and 110 (90.2%) were of nosocomial origin. During the study period, the 122 isolates showed a high rate of resistance to third-generation cephalosporins (45.9%) and extended-spectrum penicillins (56.6%). The resistance rate to ciprofloxacin was 32.0%. The resistance rate to third-generation cephalosporins increased from 31.7% for 1991 to 1995 to 54.9% for 1996 to 1998 and 50.0% for 1999 to 2001. In the multivariate analysis, prior use of a second-generation cephalosporin (adjusted odds ratio [OR], 5.90; 95% confidence interval [CI95], 1.41 to 24.6; P = .015) or a third-generation cephalosporin (OR, 3.26; CI95, 1.20 to 8.87; P = .020) was a strong independent risk factor for resistance to third-generation cephalosporins. The overall case-fatality rate was 25.4% (Serratia bacteremia-related case-fatality rate, 13.1%).
Prior use of a second- or third-generation cephalosporin was the most important risk factor for bacteremia with Serratia resistant to third-generation cephalosporins, suggesting the need for antibiotic control. The potential role of patient-to-patient spread could not be fully evaluated in this retrospective study.
The synthesis and luminescent properties of (Y,Gd)BO3:Eu phosphor were investigated. A coprecipitation method was designed for preparing Eu doped (Y,Gd)BO3. This method features a low-temperature formation of single phase with semi-spherical shape compared with the conventional method. Due to the homogeneous distribution of activator, the emission intensity of the (Y,Gd)BO3:Eu phosphor prepared by the coprecipitation method is higher than the commercially available red phosphor.
We investigated the optical properties of Fabry-Perot microcavity with a tris(8- hydroxyquinoline)aluminum (Alq3) organic film by measuring the photoluminescence (PL) and transmittance. An Alq3 layer as an active layer was sandwiched between two mirrors, which were metal or (TiO2|SiO2) dielectric multilayer reflectors. An Alq3 layer on glass, [air|Alq3|glass], showed a PL peak around 513 nm and its full width half maximum (FWHM) was about 80 nm. Three types of microcavity, such as Type A [air|metal|Alq3|metal|glass], Type B [air|dielectric|Alq3|dielectric|glass], and Type C [air|metal|Alq3|dielectric|glass], were fabricated. The result shows that the FWHMs of three Fabry-Perot microcavities were reduced to 15∼27.5, 7∼10.5 and 16∼16.6 nm, respectively, and the microcavity structure is expected to improve the efficiency and tunability of emission spectrum in display.