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A simulation method has been developed to efficiently evaluate the motion of colloidal particles in a low-Reynolds-number confined microchannel flow using a Lagrangian-based approach. In this method, the background velocity within the channel, in the absence of suspended particles, is obtained from a fluid dynamics solver and is used to update the velocity at the particle centres using the Stokesian dynamics (SD) method, which incorporates multi-body hydrodynamic interactions. As a result, instead of computing the momentum of both the fluid and particles throughout the entire computational domain, the microscopic balance equation is solved only at the particle centres, increasing the computational efficiency. To accommodate complex boundary conditions within the SD framework, imaginary particles are placed on the channel walls, allowing the mobility relation to be reformulated to apply velocity constraints to immobilized wall particles. By employing this constrained SD approach, global mobility interactions that need to be computed at each time step are limited to the interior particles, resulting in a significant reduction in computational cost. The efficiency of this study is demonstrated through case studies on particulate flows in contraction and cross-flow microchannels. By using colloidal particles that incorporate Brownian motion and inter-particle attraction, observations through the entire stages of fouling dynamics are possible, from particle inflow to channel blockage. The fouling patterns observed in the simulations are consistent with experiments conducted under the same flow conditions. This study provides an efficient approach for analysing the effect of hydrodynamic interactions on particle dynamics in microfluidics and materials processing fields while allowing for predictions about structural changes over long-time scales, including complex phenomena such as clogging.
This study examined the relationship between changes in physical activity and their impact on exercise capacity and health-related quality of life over a 3-year span in patients with CHD.
Methods:
We evaluated 99 young patients with CHD, aged 13–18 years at the outset. Physical activity, health-related quality of life, and exercise capacity were assessed via questionnaires and peak oxygen uptake measurements at baseline and after 3 years; changes in measures were estimated between the two time points and categorised into quartiles. Participants were stratified according to achieved (active) or not-achieved (inactive) recommended levels of physical activity (≥150 minutes/week) at both time points.
Results:
Despite increases in physical activity, exercise capacity, and health-related quality of life over 3 years, the changes were not statistically significant (all p > 0.05). However, a positive association was found between physical activity changes and exercise capacity (ß = 0.250, p = 0.040) and health-related quality of life improvements (ß = 0.380, p < 0.001). Those with the most pronounced physical activity increase showed notable exercise capacity (p < 0.001) and health-related quality of life increases (p < 0.001) compared with patients with the largest decline in physical activity. The active-inactive category demonstrated a notable decline in exercise capacity compared to the active-active group, while the inactive-active group showed health-related quality of life improvements.
Conclusions:
Over 3 years, increased physical activity was consistently linked to increases in exercise capacity and health-related quality of life in patients with CHD, highlighting the potential of physical activity augmentation as an intervention strategy.
We evaluated the adequacy of microbiological tests in patients withholding or withdrawing life-sustaining treatment (WLST) at the end stage of life.
Setting:
The study was conducted at 2 tertiary-care referral hospitals in Daegu, Republic of Korea.
Design:
Retrospective cross-sectional study.
Methods:
Demographic findings, clinical and epidemiological characteristics, statistics of microbiological tests, and microbial species isolated from patients within 2 weeks before death were collected in 2 tertiary-care referral hospitals from January to December 2018. We also reviewed the antimicrobial treatment that was given within 3 days of microbiological testing in patients on WLST.
Results:
Of the 1,187 hospitalized patients included, 905 patients (76.2%) had WLST. The number of tests per 1,000 patient days was higher after WLST than before WLST (242.0 vs 202.4). Among the category of microbiological tests, blood cultures were performed most frequently, and their numbers per 1,000 patient days before and after WLST were 95.9 and 99.0, respectively. The positive rates of blood culture before and after WLST were 17.2% and 18.0%, respectively. Candida spp. were the most common microbiological species in sputum (17.4%) and urine (48.2%), and Acinetobacter spp. were the most common in blood culture (17.3%). After WLST determination, 70.5% of microbiological tests did not lead to a change in antibiotic use.
Conclusions:
Many unnecessary microbiological tests are being performed in patients with WLST within 2 weeks of death. Microbiological testing should be performed carefully and in accordance with the patient’s treatment goals.
Verbascum blattaria L., commonly known as moth mullein, naturalized in the USA that produces white or yellow flowers could be considered as a potential ornamental plant. However, genetic characterization using molecular markers and leaf morphology, colourimetric analysis and flowering of V. blattaria influenced by low temperature treatments was not investigated to evaluate as a potential horticultural and landscape plant use. The basal leaves developed during the rosette-growth stage were oblanceolate with an obtuse leaf apex and incisions at the margin. Leaves produced on the stem during the reproductive development were ovate or lanceolate with an obtuse or acute leaf apex. Regardless of the colour of the petiole and leaf blade during the rosette-growth stage, there were no differences in the sequences of nuclear ribosomal ITS and chloroplast interspacer. All plants produced creamy white flowers with a purplish base corolla. All leaves formed during the vegetative and reproductive development were glabrous. Numerous stalked glandular trichomes were observed in the sepal, pedicel and bracts. Seeds started to germinate in 10 days at 25°C and reached the plateau in 30 days after sowing. The earliest flowering occurred in 131 days when the plants received 20 days of low temperature treatment (CD) (20 CD), producing 76 flowers, the highest number compared to the number of flowers produced by plants that received 0, 40 and 60 CD. Plants that received 20 CD exhibited early flowering, probably because of the early transition from vegetative growth to reproductive development, as judged by the short stem to the first flower.
In this review, we introduce our recent applications of deep learning to solar and space weather data. We have successfully applied novel deep learning methods to the following applications: (1) generation of solar farside/backside magnetograms and global field extrapolation based on them, (2) generation of solar UV/EUV images from other UV/EUV images and magnetograms, (3) denoising solar magnetograms using supervised learning, (4) generation of UV/EUV images and magnetograms from Galileo sunspot drawings, (5) improvement of global IRI TEC maps using IGS TEC ones, (6) one-day forecasting of global TEC maps through image translation, (7) generation of high-resolution magnetograms from Ca II K images, (8) super-resolution of solar magnetograms, (9) flare classification by CNN and visual explanation by attribution methods, and (10) forecasting GOES solar X-ray profiles. We present major results and discuss them. We also present future plans for integrated space weather models based on deep learning.
Several studies supported the usefulness of “the surprise question” in terms of 1-year mortality of patients. “The surprise question” requires a “Yes” or “No” answer to the question “Would I be surprised if this patient died in [specific time frame].” However, the 1-year time frame is often too long for advanced cancer patients seen by palliative care personnel. “The surprise question” with shorter time frames is needed for decision making. We examined the accuracy of “the surprise question” for 7-day, 21-day, and 42-day survival in hospitalized patients admitted to palliative care units (PCUs).
Method
This was a prospective multicenter cohort study of 130 adult patients with advanced cancer admitted to 7 hospital-based PCUs in South Korea. The accuracy of “the surprise question” was compared with that of the temporal question for clinician's prediction of survival.
Results
We analyzed 130 inpatients who died in PCUs during the study period. The median survival was 21.0 days. The sensitivity, specificity, and overall accuracy for the 7-day “the surprise question” were 46.7, 88.7, and 83.9%, respectively. The sensitivity, specificity, and overall accuracy for the 7-day temporal question were 6.7, 98.3, and 87.7%, respectively. The c-indices of the 7-day “the surprise question” and 7-day temporal question were 0.662 (95% CI: 0.539–0.785) and 0.521 (95% CI: 0.464–0.579), respectively. The c-indices of the 42-day “the surprise question” and 42-day temporal question were 0.554 (95% CI: 0.509–0.599) and 0.616 (95% CI: 0.569–0.663), respectively.
Significance of results
Surprisingly, “the surprise questions” and temporal questions had similar accuracies. The high specificities for the 7-day “the surprise question” and 7- and 21-day temporal question suggest they may be useful to rule in death if positive.
The explosive outbreak of COVID-19 led to a shortage of medical resources, including isolation rooms in hospitals, healthcare workers (HCWs) and personal protective equipment. Here, we constructed a new model, non-contact community treatment centres to monitor and quarantine asymptomatic and mildly symptomatic COVID-19 patients who recorded their own vital signs using a smartphone application. This new model in Korea is useful to overcome shortages of medical resources and to minimise the risk of infection transmission to HCWs.
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.
Methods
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.
Results
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.
Conclusion
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.
Vegetables are an important source for the essential vitamins and minerals that are necessary for optimal health. This research investigated changes in vegetable intake over time in the Korean population from 1998 to 2017, focusing on preparation methods of vegetables and location of consumption. This cross-sectional study is based on the Korea National Health and Nutrition Examination Survey (KNHANES) that was established in 1998 to assess the health and nutritional status of the South Korean population. This research utilised information from 1998 to 2017 which is the extent of all available KNHANES data. Vegetable consumption was grouped, according to preparation methods and common eating locations. Both crude and age-standardised means of vegetable intake were derived via a 24-h dietary recall. All participants who completed a 24-h dietary recall survey were selected for the analyses. This included 109 220 individuals (49 069 men and 60 151 women) over the course of 20 years of the KNHANES. Total vegetable intake decreased over time (Pfor trends < 0·001), specifically, steamed and salted vegetables (Pfor trends < 0·001). In contrast, Koreans consumed noticeably more raw vegetables from 1998 to 2017 (Pfor trends < 0·001). Vegetable intake at home significantly declined (Pfor trends < 0·001), while that eaten at restaurants or outside the home increased greatly (Pfor trends < 0·001). Over 20 years, Koreans have ingested decreasing amounts of vegetables, but the intake of raw vegetables has escalated. However, the location of vegetable consumption has changed, with an increase at both restaurants and outside the home (approximately 70·0 %).
To date, there have been few studies on dietary supplement (DS) use in Korean children and adolescents, using nationally representative data. This study aimed to investigate the current status of DS use and its related factors, among Korean children and adolescents from the Korean National Health and Nutrition Examination Survey (KNHANES) data.
Design:
A cross-sectional study.
Setting:
Data from the KNHANES 2015–2017. Participants completed 24-h dietary recall interviews, including DS products that the subjects consumed.
Participants:
The study population was 4380 children and adolescents aged 1–18 years.
Results:
Approximately 2013 % of children and adolescents were using DS; the highest use was among children aged 1–3 years old, and the lowest use was among adolescents aged 16–18 years. The most frequently used DS was prebiotics/probiotics, followed by multivitamin/mineral supplements. Factors that were associated with DS use were lower birth weight in children aged <4 years; younger age, higher household income, regular breakfast intake and lower BMI in children aged 4–9 years; and regular breakfast intake and use of nutrition facts label in adolescents aged 10–18 years. Feeding patterns in infancy and having chronic diseases were not associated with DS use.
Conclusions:
We report that over 20 % of children and adolescents use DS. Nutritional education for parents and children about proper DS consumption is needed.
Early replacement of a new central venous catheter (CVC) may pose a risk of persistent or recurrent infection in patients with a catheter-related bloodstream infection (CRBSI). We evaluated the clinical impact of early CVC reinsertion after catheter removal in patients with CRBSIs.
Methods:
We conducted a retrospective chart review of adult patients with confirmed CRBSIs in 2 tertiary-care hospitals over a 7-year period.
Results:
To treat their infections, 316 patients with CRBSIs underwent CVC removal. Among them, 130 (41.1%) underwent early CVC reinsertion (≤3 days after CVC removal), 39 (12.4%) underwent delayed reinsertion (>3 days), and 147 (46.5%) did not undergo CVC reinsertion. There were no differences in baseline characteristics among the 3 groups, except for nontunneled CVC, presence of septic shock, and reason for CVC reinsertion. The rate of persistent CRBSI in the early CVC reinsertion group (22.3%) was higher than that in the no CVC reinsertion group (7.5%; P = .002) but was similar to that in the delayed CVC reinsertion group (17.9%; P > .99). The other clinical outcomes did not differ among the 3 groups, including rates of 30-day mortality, complicated infection, and recurrence. After controlling for several confounding factors, early CVC reinsertion was not significantly associated with persistent CRBSI (OR, 1.59; P = .35) or 30-day mortality compared with delayed CVC reinsertion (OR, 0.81; P = .68).
Conclusions:
Early CVC reinsertion in the setting of CRBSI may be safe. Replacement of a new CVC should not be delayed in patients who still require a CVC for ongoing management.
Fermented foods such as kimchi are traditional foods in Korea and could provide beneficial health effects. However, fermented foods also contribute to increased Na intake since salt is added during the fermentation process. The present research aimed to examine trends in the consumption of fermented foods and Na intake over time by Korean adults, using data from the Korea National Health and Nutrition Examination Survey (KNHANES).
Design:
KNHANES is a cross-sectional survey; data from 1998 to 2016 were divided into seven groups from KNHANES I to VII.
Setting:
Demographic information on sex, age, education and income were collected. Assessment of fermented food and Na consumption was conducted via analysis of 24 h dietary recall data. Multivariate linear regressions and logistic regressions were performed to calculate the P for trends by applying strata, cluster and sampling weights by SAS PROC SURVEY.
Participants:
The target population was Korean adults, aged ≥19 years, who participated in a 24 h dietary recall. The total number was 76 199, with 32 324 men and 43 875 women.
Results:
A significant decline in fermented food consumption was observed from 1998 to 2016 in both men and women (P < 0·0001). Among fermented foods, kimchi consumption was greatly reduced while pickled vegetables consumption showed a marked increase. Similarly, Na intake from fermented foods declined significantly over time in both men and women (P < 0·0001).
Conclusions:
The consumption of fermented foods and Na intake from fermented foods by Korean adults decreased significantly over time from 1998 to 2016.
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.
Method
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.
Result
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.
Given its diverse disease courses and symptom presentations, multiple phenotype dimensions with different biological underpinnings are expected with bipolar disorders (BPs). In this study, we aimed to identify lifetime BP psychopathology dimensions. We also explored the differing associations with bipolar I (BP-I) and bipolar II (BP-II) disorders.
Methods
We included a total of 307 subjects with BPs in the analysis. For the factor analysis, we chose six variables related to clinical courses, 29 indicators covering lifetime symptoms of mood episodes, and 6 specific comorbid conditions. To determine the relationships among the identified phenotypic dimensions and their effects on differentiating BP subtypes, we applied structural equation modeling.
Results
We selected a six-factor solution through scree plot, Velicer's minimum average partial test, and face validity evaluations; the six factors were cyclicity, depression, atypical vegetative symptoms, elation, psychotic/irritable mania, and comorbidity. In the path analysis, five factors excluding atypical vegetative symptoms were associated with one another. Cyclicity, depression, and comorbidity had positive associations, and they correlated negatively with psychotic/irritable mania; elation showed positive correlations with cyclicity and psychotic/irritable mania. Depression, cyclicity, and comorbidity were stronger in BP-II than in BP-I, and they contributed significantly to the distinction between the two disorders.
Conclusions
We identified six phenotype dimensions; in addition to symptom features of manic and depressive episodes, various comorbidities and high cyclicity constructed separate dimensions. Except for atypical vegetative symptoms, all factors showed a complex interdependency and played roles in discriminating BP-II from BP-I.
Clonorchis sinensis (C. sinensis), a trematode parasite that invades the hypoxic hepatobiliary tract of vertebrate hosts requires a considerable amount of oxygen for its sexual reproduction and energy metabolism. However, little is known regarding the molecular mechanism of C. sinensis involved in the adaptation to the hypoxic environments. In this study, we investigated the molecular structures and induction patterns of hypoxia-inducible factor-1α (HIF-1α) and other basic helix–loop–helix and Per–Arnt–Sim (bHLH–PAS) domain-containing proteins such as HIF-1β, single-minded protein and aryl hydrocarbon receptor, which might prompt adaptive response to hypoxia, in C. sinensis. These proteins possessed various bHLH–PAS family-specific domains. Expression of C. sinensis HIF-1α (CsHIF-1α) was highly induced in worms which were either exposed to a hypoxic condition or co-incubated with human cholangiocytes. In addition to oxygen, nitric oxide and nitrite affected the CsHIF-1α expression depending on the surrounding oxygen concentration. Treatment using a prolyl hydroxylase-domain protein inhibitor under 20%-oxygen condition resulted in an increase in the CsHIF-1α level. Conversely, the other bHLH–PAS genes were less responsive to these exogenous stimuli. We suggest that nitrite and nitric oxide, as well as oxygen, coordinately involve in the regulation of HIF-1α expression to adapt to the hypoxic host environments in C. sinensis.
Depressive symptoms are common in bereaved caregivers; however, there have been few prospective studies using a structured interview. This study investigated the prevalence and preloss predictors of major depressive disorder (MDD) in bereaved caregivers of patients in a palliative care unit.
Method
This prospective cohort study collected caregiver sociodemographic and psychological data before the death of a palliative care unit patient, including MDD, care-burden, coping style, and hopeful attitude. Postloss MDD was assessed 6 and 13 months after death, and a multivariate logistic regression analysis was conducted to identify its predictors.
Result
Of 305 caregivers contacted, 92 participated in this study. The prevalence of preloss MDD was 21.8%; the prevalences of postloss MDD were 34.8% and 24.7% at 6 and 13 months, respectively. Preloss MDD predicted postloss MDD at 6 months (odds ratio [OR] = 5.38, 95% confidence interval [CI95%] = 1.29, 22.43); preloss nonhopeful attitude and unemployment status of caregivers predicted postloss MDD at 13 months (OR = 8.77, CI95% = 1.87, 41.13 and OR = 7.10, CI95% = 1.28, 39.36, respectively).
Significance of results
Approximately 35% of caregivers suffered from MDD at 6 months postloss, but the prevalence of MDD decreased to about 25% at 13 months. Preloss MDD significantly predicted postloss MDD at 6 months, whereas hopeful attitude and unemployment at baseline were significantly associated with postloss MDD at 13 months.
Despite their importance in the formation and evolution of stellar clusters and galaxies, the formation of high-mass stars remains poorly understood. We recently started a systematic observational study of the 22 GHz water and 44 GHz class I methanol masers in high-mass star-forming regions as a four-year KaVA large program. Our sample consists of 87 high-mass young stellar objects (HM-YSOs) in various evolutionary phases, many of which are associated with two or more different maser species. The primary scientific goals are to measure the spatial distributions and 3-dimensional velocity fields of multiple maser species, and understand the dynamical evolution of HM-YSOs and their circumstellar structures, in conjunction with follow-up observations with JVN/EAVN (6.7 GHz class II methanol masers), VERA, and ALMA. In this paper we present details of our KaVA large program, including the first-year results and observing/data analysis plans for the second year and beyond.
We present the results of the linear polarisation observations of methanol masers at 44 and 95 GHz towards 39 massive star forming regions (Kang et al. 2016). These two lines are observed simultaneously with the 21-m Korean VLBI Network (KVN) telescope in single dish mode. About 60% of the observed showed fractional polarisation of a few percents at least at one of the two transition lines. We note that the linear polarisation of the 44 GHz methanol maser is first detected in this study including single dish and interferometer observations. We find the polarisation properties of these two lines are similar as expected, since they trace similar regions. As a follow-up study, we have carried out the VLBI polarisation observations toward some 44 GHz maser targets using the KVN telescope. We present preliminary VLBI polarisation results of G10.34-0.14, which show consistent polarisation properties in multiple epoch observations.