Potassium ions as a kinetic controller in ionic double layers for hysteresis-free perovskite solar cells

Since ion migration and interaction with external contacts has been regarded as one of the origins for photocurrent density (J)–voltage (V) hysteresis and phase segregation in perovskite solar cells (PSCs) under operational condition, control of ionic movement in organic–inorganic halide perovskites presents a big challenge for achieving hysteresis-free and stable PSCs. As a universal method, potassium doping into bulk perovskite films to minimize or eliminate the hysteresis was proposed. Here, we report direct observation of moderately retarded ion migration in K+-doped (FAPbI3)0.875(CsPbBr3)0.125 perovskite by in situ photoluminescence (PL) imaging. However, more impressive is the effect on the kinetics for generation of the ionic double layer in the vicinity of the contacts as it is reduced by two orders of magnitude on the time scale when devices are doped with K+ as detected by impedance spectroscopy. A significantly reduced hysteresis in the K+-doped perovskite is responsible for more prolonged stability exhibiting ∼96% of initial power conversion efficiency (PCE) after 22 days than relatively short-lived perovskites undoped with K+ ions. This work highlights the clear correlation of ion migration and a fast generation of the double layer close to the contacts with severe hysteresis and long-term instability in PSCs and the importance of K+ ions in reducing the kinetics affecting the ionic attachment to the contact surface

Market Segmentation Based on Attributes for the Purchase of Fresh Ginseng

This study aims to subdivide consumers by attributes determined mainly by consumers of fresh ginseng. It is to compare and analyze the characteristics by cluster, and to deduce the implications on distribution and marketing. For this study, a survey was conducted targeting 250 consumers of fresh ginseng. The factors were deduced through performing the exploratory factor analysis on the results of the survey, and the consumers of fresh ginseng were classified through cluster analysis. As a result of the study, the attributes considered for the purchase of fresh ginseng were condensed to the three factors: physical characteristic factor, safety factor, and cultivation indication information factor. With these as the standard, the consumers of fresh ginseng were subdivided into the three clusters: safety-oriented consumption type, label-centered consumption type, and high involvement consumption type. It was found that there were differences in demographic characteristics and attributes considered for purchase of fresh ginseng by cluster analysis. This study suggests the implications for revitalization of the fresh ginseng industry by subdividing consumers of fresh ginseng and suggesting the characteristics by cluster.This research was financially supported by the Rural Development Administration (RDA) of Korea (Grant No.PJ008729).OAIID:oai:osos.snu.ac.kr:snu2012-01/102/0000011251/8SEQ:8PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:0000011251ADJUST_YN:NEMP_ID:A078501DEPT_CD:520CITE_RATE:0FILENAME:첨부된 내역이 없습니다.DEPT_NM:농경제사회학부EMAIL:[email protected]_YN:NCONFIRM:

Stratifying non-small cell lung cancer patients using an inverse of the treatment decision rules: validation using electronic health records with application to an administrative database

To validate a stratification method using an inverse of treatment decision rules that can classify non-small cell lung cancer (NSCLC) patients in real-world treatment records. (1) To validate the index classifier against the TNM 7th edition, we analyzed electronic health records of NSCLC patients diagnosed from 2011 to 2015 in a tertiary referral hospital in Seoul, Korea. Predictive accuracy, stage-specific sensitivity, specificity, positive predictive value, negative predictive value, F1 score, and c-statistic were measured. (2) To apply the index classifier in an administrative database, we analyzed NSCLC patients in Korean National Health Insurance Database, 2002–2013. Differential survival rates among the classes were examined with the log-rank test, and class-specific survival rates were compared with the reference survival rates. (1) In the validation study (N = 1375), the overall accuracy was 93.8% (95% CI: 92.5–95.0%). Stage-specific c-statistic was the highest for stage I (0.97, 95% CI: 0.96–0.98) and the lowest for stage III (0.82, 95% CI: 0.77–0.87). (2) In the application study (N = 71,593), the index classifier showed a tendency for differentiating survival probabilities among classes. Compared to the reference TNM survival rates, the index classification under-estimated the survival probability for stages IA, IIIB, and IV, and over-estimated it for stages IIA and IIB. The inverse of the treatment decision rules has a potential to supplement a routinely collected database with information encoded in the treatment decision rules to classify NSCLC patients. It requires further validation and replication in multiple clinical settings

Diagnostic Accuracy of Fine-Needle Aspiration Cytology and Core-Needle Biopsy in the Assessment of the Axillary Lymph Nodes in Breast Cancer—A Meta-Analysis

Background: The present study aims to evaluate the diagnostic accuracy between ultrasonography-guided fine-needle aspiration cytology (US-FNAC) and core needle biopsy (CNB) of axillary lymph nodes (ALNs) in patients with breast cancer through a meta-analysis and a diagnostic test accuracy (DTA) review. Methods: The present meta-analysis and DTA review included 67 eligible studies. The diagnostic accuracy of various preoperative assessments, including US-FNAC and CNB, was evaluated for ALNs assessments in patients with breast cancer. In addition, a subgroup analysis based on methods of cytologic preparation was performed. In the DTA review, the sensitivity, specificity, diagnostic odds ratio (OR) and area under the curve (AUC) on the summary receiver operating characteristic (SROC) curve were calculated. Results: The diagnostic accuracy of the preoperative assessments of ALNs was 0.850 (95% confidence interval (CI) 0.833–0.866) for patients with breast cancer. The diagnostic accuracy of CNB was significantly higher than that of US-FNAC (0.896, 95% CI 0.844–0.932 vs. 0.844, 95% CI 0.825–0.862; p = 0.044 in a meta-regression test). In the subgroup analysis based on cytologic preparation, the diagnosis accuracies were 0.860, 0.861 and 0.859 for the methods of conventional smear, liquid-based preparation and cell block, respectively. In the DTA review, CNB showed higher sensitivity than US-FNAC (0.849 vs. 0.760). However, there was no difference in specificity between US-FNAC and CNB (0.997 vs. 1.000). US-FNAC with liquid-based preparation and CNB showed the highest diagnostic OR and AUC on the SROC, respectively. Conclusion: Both US-FNAC and CNB are useful in preoperative assessments of ALNs in patients with breast cancer. Although the most sensitive test was found to be CNB in this study, there was no difference in specificity between various preoperative evaluations and the application of US-FNAC or CNB may be impacted by various factors

Cerebral and Somatic Oxygen Saturation in Neonates with Congenital Heart Disease before Surgery

Background: We investigated preoperative cerebral (ScO2) and abdominal (StO2) regional oxygen saturations according to cardiac diagnosis in neonates with critical CHD, their time trends, and the clinical and biochemical parameters associated with them. Methods: Thirty-seven neonates with a prenatal diagnosis of CHD were included. ScO2 and StO2 values were continuously evaluated using near-infrared spectroscopy. Measurements were obtained hourly before surgery. A linear mixed effects model was used to assess the effects of time and cardiac diagnosis on regional oxygenation and to explore the contributing factors. Results: Regional oxygenation differed according to cardiac diagnosis (p < 0.001). ScO2 was lowest in the patients with severe atrioventricular valvar regurgitation (AVVR) (48.1 ± 8.0%). StO2 tended to be lower than ScO2, and both worsened gradually during the period between birth and surgery. There was also a significant interaction between cardiac diagnosis and time. The factors related to ScO2 were hemoglobin and arterial saturation, whereas no factor was associated with StO2. Conclusions: Preoperative ScO2 and StO2 in critical CHD differed according to cardiac diagnosis. ScO2 in the patients with severe AVVR was very low, which may imply cerebral hypoxia. ScO2 gradually decreased, suggesting that the longer the time to surgery, the higher the risk of hypoxic brain injury

Bioconverted Orostachys japonicas Extracts Suppress Angiogenic Activity of Ms-1 Endothelial Cells

Orostachys japonicus A. Berger (), known as Wa-song in Korea, has been reported to exert various biological effects, such as anti-tumor, anti-oxidant, and anti-febrile effects. However, the anti-angiogenic effects of O. japonicus extracts remain to be investigated. In the present study, we demonstrated the anti-angiogenic effects of bioconverted O. japonicus extract (BOE) in Ms-1 mouse endothelial cells and compared them with the bioactivities of O. japonicus extract (OE). BOE, but not OE, were found to exert anti-angiogenic effects, including inhibition of cell migration, cell adhesion, tube formation of Ms-1 cells, and blood vessel formation of matrigel plug assay in vivo. Furthermore, protein levels of phosphorylated Src kinase were lower in BOE-treated cells than in OE-treated cells. Treatment with OE or BOE did not influence cell viability during the experimental period. Bioconverted extract of O. japonicus have anti-angiogenic effects in vitro and vivo, but non-bioconverted extract do not. We suggest that these observed anti-angiogenic effects are caused by the changes in the composition of bioactive compounds in the extracts as a result of biological conversion

Therapeutic effect of human mesenchymal stem cell-conditioned medium on erectile dysfunction

Purpose: Owing to the safety and cost effectiveness of conditioned medium (CM), its therapeutic effects have attracted signifi-cant attention from many researchers. To date, numerous studies have been conducted on CM; however, little has been done with regard to erectile dysfunction (ED). In this research, the potential of human mesenchymal stem cell-derived CM (MSC-CM) for the treatment of ED was investigated. Materials and Methods: A high concentration of MSC-CM was prepared through 3D spheroid culturing with bone marrow-derived MSCs and cut-off filtering. The composition of CM was analyzed using biochemical assays, and the effect of the preparation process on the quality of CM was investigated. The therapeutic effects of MSC-CM were evaluated through ani-mal studies using a cavernous nerve (CN) injury rat model. Results: 3D spheroid culturing afforded a 278-fold increase in the total protein content of CM, as compared to that from 2D cultures; the protein concentration increased by 19 times on increasing the centrifugation time for cut-off filtering. Biochemi-cal assays indicated that the CM contains various types of angiogenic, neurotrophic, and anti-inflammatory factors. Histologi -cal assay results showed that MSC-CM has angio-and neuro-trophic effect in a CN injury rat model in vivo, and these thera-peutic effects appear in a dose-dependent manner. Conclusions: The experimental results confirmed the therapeutic effect of MSC-CM in healing damaged cavernosal tissue and restoring erectile function. These results successfully demonstrated that MSC-CM has significant potential for the treatment of ED

Factors for starting biosimilar TNF inhibitors in patients with rheumatic diseases in the real world.

BACKGROUND:To identify factors for starting biosimilar TNF inhibitors (TNFI) in patients with rheumatic diseases. METHODS AND FINDING:Using a national claims database, we identified patients with rheumatoid arthritis (RA) or ankylosing spondylitis (AS) who had used TNFIs since they were approved in Korea in 2004. We assessed changes in the proportion of each form of TNFI used between 2004 and 2017. We then selected patients starting on TNFIs between 2013 and 2017 to identify factors for starting biosimilars. In RA (n = 4,216), biosimilars were more likely to be initiated in clinics [odds ratio (OR) 2.54] and in the metropolitan area (OR, 2.02), but were less likely to be initiated in general hospitals (OR 0.40) or orthopedics (OR 0.44). In AS (n = 2,338), biosimilars were common at the hospital level (OR 2.20) and tended to increase over the years (OR 1.16), but were initiated less in orthopedics (OR 0.07). In addition, RA patients were more likely to initiate biosimilars in combination with methotrexate (OR 1.37), but biosimilars were not initiated frequently by patients with higher comorbidity scores (OR 0.97) or receiving glucocorticoids (OR 0.67). The patient factors favoring biosimilar in AS use were not clear. CONCLUSIONS:In Korea, the proportion of biosimilar TNFIs has increased. Type of institution and physician specialty are more important than patient factors in affecting biosimilar use. In RA, biosimilar TNFIs tend to be initiated in combination with MTX, and are less likely to be initiated in patients taking glucocorticoids or in those with high comorbidities

In vivo tracking of 14C thymidine labeled mesenchymal stem cells using ultra-sensitive accelerator mass spectrometry

Abstract Despite the tremendous advancements made in cell tracking, in vivo imaging and volumetric analysis, it remains difficult to accurately quantify the number of infused cells following stem cell therapy, especially at the single cell level, mainly due to the sensitivity of cells. In this study, we demonstrate the utility of both liquid scintillator counter (LSC) and accelerator mass spectrometry (AMS) in investigating the distribution and quantification of radioisotope labeled adipocyte derived mesenchymal stem cells (AD-MSCs) at the single cell level after intravenous (IV) transplantation. We first show the incorporation of 14C-thymidine (5 nCi/ml, 24.2 ng/ml) into AD-MSCs without affecting key biological characteristics. These cells were then utilized to track and quantify the distribution of AD-MSCs delivered through the tail vein by AMS, revealing the number of AD-MSCs existing within different organs per mg and per organ at different time points. Notably, the results show that this highly sensitive approach can quantify one cell per mg which effectively means that AD-MSCs can be detected in various tissues at the single cell level. While the significance of these cells is yet to be elucidated, we show that it is possible to accurately depict the pattern of distribution and quantify AD-MSCs in living tissue. This approach can serve to incrementally build profiles of biodistribution for stem cells such as MSCs which is essential for both research and therapeutic purposes