136 research outputs found
Recent Progress in Plasmonic Hybrid Photocatalysis for CO2 Photoreduction and C-C Coupling Reactions
Plasmonic hybrid nanostructures have been investigated as attractive heterogeneous photocatalysts that can utilize sunlight to produce valuable chemicals. In particular, the efficient photoconversion of CO2 into a stable hydrocarbon with sunlight can be a promising strategy to achieve a sustainable human life on Earth. The next step for hydrocarbons once obtained from CO2 is the carbon-carbon coupling reactions to produce a valuable chemical for energy storage or fine chemicals. For these purposes, plasmonic nanomaterials have been widely investigated as a visible-light-induced photocatalyst to achieve increased efficiency of photochemical reactions with sunlight. In this review, we discuss recent achievements involving plasmonic hybrid photocatalysts that have been investigated for CO and CO2 photoreductions to form multi-carbon products and for C-C coupling reactions, such as the Suzuki-Miyaura coupling reactions
Clinical characteristics of 2009 pandemic influenza A (H1N1) infection in children and the performance of rapid antigen test
PurposeIn autumn 2009, the swine-origin influenza A (H1N1) virus spread throughout South Korea. The aims of this study were to determine the clinical characteristics of children infected by the 2009 H1N1 influenza A virus, and to compare the rapid antigen and real-time polymerase chain reaction (PCR) tests.MethodsWe conducted a retrospective review of patients โฅ18 years of age who presented to Soonchunhyang University Hospital in Seoul with respiratory symptoms, including fever, between September 2009 and January 2010. A real-time PCR test was used to definitively diagnose 2009 H1N1 influenza A infection. Medical records of confirmed cases were reviewed for sex, age, and the time of infection. The decision to perform rapid antigen testing was not influenced by clinical conditions, but by individual factors such as economic conditions. Its sensitivity and specificity were evaluated compared to real-time PCR test results.ResultsIn total, 934 patients tested positive for H1N1 by real-time PCR. The highest number of patients (48.9%) was diagnosed in November. Most patients (48.2%) were aged between 6 and 10 years. Compared with the H1N1 real-time PCR test results, the rapid antigen test showed 22% sensitivity and 83% specificity. Seventy-eight patients were hospitalized for H1N1 influenza A virus infection, and fever was the most common symptom (97.4%).ConclusionFor diagnosis of 2009 H1N1 influenza A virus infection, the rapid antigen test was inferior to the real-time PCR test in both sensitivity and specificity. This outcome suggests that the rapid antigen test is inappropriate for screening
Association Between Serum Uric Acid Level and Metabolic Syndrome
OBJECTIVES: Serum uric acid levels have been reported to be associated with a variety of cardiovascular conditions. However, the direct association between uric acid levels and metabolic syndrome remains controversial. Thus, we evaluated the association of serum uric acid levels and metabolic syndrome in a community-based cohort study in Korea.
METHODS: We performed cross-sectional analysis of baseline data of 889 males and 1491 females (aged 38 to 87) who participated in baseline examinations of the Korean Genome and Epidemiology Study: Kanghwa study. Blood samples were collected after at least an 8 hour fast. Uric acid quartiles were defined as follows: <4.8, 4.8-<5.6, 5.6-<6.5, โฅ6.5 mg/dL in males; and <3.8, 3.8-<4.3, 4.3-<5.1, โฅ5.1 mg/dL in females. Metabolic syndrome was defined by the National Cholesterol Education Program Adult Treatment Panel III Criteria with adjusted waist circumference cutoffs (90 cm for males; 80 cm for females). The association between serum uric acid quartiles and metabolic syndrome was assessed using multivariate logistic regression.
RESULTS: The odds ratio for having metabolic syndrome in the highest versus lowest quartiles of serum uric acid levels was 2.67 (95% confidence interval [CI], 1.60 to 4.46) in males and 2.14 (95% CI, 1.50 to 3.05) in females after adjusting for age, smoking, alcohol intake, body mass index, total cholesterol, HbA1c, albumin, ฮณ-glutamyltransferase, blood urea nitrogen, and log C-reactive protein. The number of metabolic abnormalities also increased gradually with increasing serum uric acid levels (adjusted p for trend < 0.001 in both sexes).
CONCLUSIONS: Higher serum uric acid levels are positively associated with the presence of metabolic syndrome in Korean males and females.ope
Effect of a heat treatment on the precipitation behavior and tensile properties of alloy 690 steam generator tubes
The intergranular carbide precipitation behavior and its effect on the tensile properties were investigated in alloy 690. The precipitation of intergranular carbides, identified as Cr-rich M23C6, was retarded on the low-angle grain boundaries and the coincidence-site lattice boundaries. The M23C6 carbides have a cube-cube orientation relationship with the matrix. The ultimate tensile strength, yield strength, and elongation of the solution annealed alloy 690 are 648.2 ยฑ 8.2 MPa, 242.8 ยฑ 10.5 MPa and 44.9 ยฑ 2.3%, respectively. The ultimate tensile strength and the yield strength increased to 764.8 ยฑ 7.8 MPa and 364.8 ยฑ 10.2 MPa until the aging time reached 16 h. This increase is ascribed to the M23C6 carbide acting as reinforcements. However, when the aging time exceed 16 h, these properties gradually decreased with increasing aging time. The decrease in ultimate tensile strength, yield strength, and elongation were mainly caused by the intergranular cracking due to the low bond strength between the carbide and the matrix
Rapid Hepatobiliary Excretion of Micelle-Encapsulated/Radiolabeled Upconverting Nanoparticles as an Integrated Form
In the field of nanomedicine, long term accumulation of nanoparticles (NPs) in the mononuclear phagocyte system (MPS) such as liver is the major hurdle in clinical translation. On the other hand, NPs could be excreted via hepatobiliary excretion pathway without overt tissue toxicity. Therefore, it is critical to develop NPs that show favorable excretion property. Herein, we demonstrated that micelle encapsulated Cu-64-labeled upconverting nanoparticles (micelle encapsulated Cu-64-NOTA-UCNPs) showed substantial hepatobiliary excretion by in vivo positron emission tomography (PET) and also upconversion luminescence imaging (ULI). Ex vivo biodistribution study reinforced the imaging results by showing clearance of 84% of initial hepatic uptake in 72 hours. Hepatobiliary excretion of the UCNPs was also verified by transmission electron microscopy (TEM) examination. Micelle encapsulated Cu-64-NOTA-UCNPs could be an optimal bimodal imaging agent owing to quantifiability of Cu-64, ability of in vivo/ex vivo ULI and good hepatobiliary excretion property.
Inhibition of histone deacetylase 6 suppresses inflammatory responses and invasiveness of fibroblast-like-synoviocytes in inflammatory arthritis
Background
To investigate the effects of inhibiting histone deacetylase (HDAC) 6 on inflammatory responses and tissue-destructive functions of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA).
Methods
FLS from RA patients were activated with interleukin (IL)-1ฮฒ in the presence of increasing concentrations of M808, a novel specific HDAC6 inhibitor. Production of ILs, chemokines, and metalloproteinases (MMPs) was measured in ELISAs. Acetylation of tubulin and expression of ICAM-1 and VCAM-1 were assessed by Western blotting. Wound healing and adhesion assays were performed. Cytoskeletal organization was visualized by immunofluorescence. Finally, the impact of HDAC6 inhibition on the severity of arthritis and joint histology was examined in a murine model of adjuvant-induced arthritis (AIA).
Results
HDAC6 was selectively inhibited by M808. The HDAC6 inhibitor suppressed the production of MMP-1, MMP-3, IL-6, CCL2, CXCL8, and CXCL10 by RA-FLS in response to IL-1ฮฒ. Increased acetylation of tubulin was associated with decreased migration of RA-FLS. Inhibiting HDAC6 induced cytoskeletal reorganization in RA-FLS by suppressing the formation of invadopodia following activation with IL-1ฮฒ. In addition, M808 tended to decrease the expression of ICAM-1 and VCAM-1. In the AIA arthritis model, M808 improved the clinical arthritis score in a dose-dependent manner. Also, HDAC6 inhibition was associated with less severe synovial inflammation and joint destruction.
Conclusion
Inhibiting HDAC6 dampens the inflammatory and destructive activity of RA-FLS and reduces the severity of arthritis. Thus, targeting HDAC6 has therapeutic potential.This study was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number:HI14C1277); the Ministry of Science, ICT and Future Planning (NRF2020M3E5E2037430, 2019M3A9A8065574); and the Chong Kun Dang
Pharmaceutical Corp. TP was supported by the DFG (FOR2722)
CCN1 interlinks integrin and hippo pathway to autoregulate tip cell activity
CCN1 (CYR61) stimulates active angiogenesis in various tumours, although the mechanism is largely unknown. Here, we report that CCN1 is a key regulator of endothelial tip cell activity in angiogenesis. Microvessel networks and directional vascular cell migration patterns were deformed in ccn1-knockdown zebrafish embryos. CCN1 activated VEGFR2 and downstream MAPK/PI3K signalling pathways, YAP/TAZ, as well as Rho effector mDia1 to enhance tip cell activity and CCN1 itself. VEGFR2 interacted with integrin ฮฑvฮฒ3 through CCN1. Integrin ฮฑvฮฒ3 inhibitor repressed tip cell number and sprouting in postnatal retinas from endothelial cell-specific Ccn1 transgenic mice, and allograft tumours in Ccn1 transgenic mice showed hyperactive vascular sprouting. Cancer patients with high CCN1 expression have poor survival outcomes and positive correlation with ITGAV and ITGB3 and high YAP/WWTR1. Thus, our data underscore the positive feedback regulation of tip cells by CCN1 through integrin ฮฑvฮฒ3/VEGFR2 and increased YAP/TAZ activity, suggesting a promising therapeutic intervention for pathological angiogenesis. ยฉ 2019, Park et al.1
Clinical significance of cytogenetic aberrations in bone marrow of patients with diffuse large B-cell lymphoma: prognostic significance and relevance to histologic involvement
Background : Although knowledge of the genetics of diffuse large B-cell lymphoma (DLBCL) has been increasing, little is known about the characteristics and prognostic significance of cytogenetic abnormalities and the clinical utility of cytogenetic studies performed on bone marrow (BM) specimens. To investigate the significance of isolated cytogenetic aberrations in the absence of histologic BM involvement, we assessed the implication of cytogenetic staging and prognostic stratification by a retrospective multicenter analysis of newly diagnosed DLBCL patients.
Methods : We analyzed cytogenetic and clinical data from 1585 DLBCL patients whose BM aspirates had been subjected to conventional karyotyping for staging. If available, interphase fluorescence in situ hybridization (FISH) data were also collected from patients.
Results : Histologic BM involvement were found in 259/1585 (16.3%) patients and chromosomal abnormalities were detected in 192 (12.1%) patients (54 patients with single abnormalities and 138 patients with 2 or more abnormalities). Isolated cytogenetic aberrations (2 or more abnormalities) without histologic involvement were found in 21 patients (1.3%). Two or more cytogenetic abnormalities were associated with inferior overall survival (OS) compared with a normal karyotype or single abnormality in both patients with histologic BM involvement (5-year OS, 16.5% vs. 52.7%; P < 0.001) and those without BM involvement (31.8% vs. 66.5%; P < 0.001). This result demonstrated that BM cytogenetic results have a significant prognostic impact that is independent of BM histology. The following abnormalities were most frequently observed: rearrangements involving 14q32, 19q13, 19p13, 1p, 3q27, and 8q24; del(6q); dup(1q); and trisomy 18. In univariate analysis, several specific abnormalities including abnormalities at 16q22-q24, 6p21-p25, 12q22-q24, and -17 were associated with poor prognosis. Multivariate analyses performed for patients who had either chromosomal abnormalities or histologic BM involvement, revealed IPI high risk, โฅ 2 cytogenetic abnormalities, and several specific chromosomal abnormalities, including abnormalities at 19p13, 12q22-q24, 8q24, and 19q13 were significantly associated with a worse prognosis. Conclusions : We suggest that isolated cytogenetic aberrations can be regarded as BM involvement and cytogenetic evaluation of BM improves staging accuracy along with prognostic information for DLBCL patients.This work was supported by (1) the Basic Science Research Program through the National Research Foundation of Korea (NRF) Funded by the Ministry of Education, Science and Technology (2012โ0002257), (2) a grant (10172KFDA993) from Korea Food & Drug Administration, (3) a grant of the Korean Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (A120216).Peer Reviewe
The Association Between Serum Albumin Levels and Metabolic Syndrome in a Rural Population of Korea
Association between cord blood 25-hydroxyvitamin D concentrations and respiratory tract infections in the first 6 months of age in a Korean population: a birth cohort study (COCOA)
PurposePrevious studies suggest that the concentration of 25-hydroxyvitamin D [25(OH)D] in cord blood may show an inverse association with respiratory tract infections (RTI) during childhood. The aim of the present study was to examine the influence of 25(OH)D concentrations in cord blood on infant RTI in a Korean birth cohort.MethodsThe levels of 25(OH)D in cord blood obtained from 525 Korean newborns in the prospective COhort for Childhood Origin of Asthma and allergic diseases were examined. The primary outcome variable of interest was the prevalence of RTI at 6-month follow-up, as diagnosed by pediatricians and pediatric allergy and pulmonology specialists. RTI included acute nasopharyngitis, rhinosinusitis, otitis media, croup, tracheobronchitis, bronchiolitis, and pneumonia.ResultsThe median concentration of 25(OH)D in cord blood was 32.0 nmol/L (interquartile range, 21.4 to 53.2). One hundred and eighty neonates (34.3%) showed 25(OH)D concentrations less than 25.0 nmol/L, 292 (55.6%) showed 25(OH)D concentrations of 25.0-74.9 nmol/L, and 53 (10.1%) showed concentrations of โฅ75.0 nmol/L. Adjusting for the season of birth, multivitamin intake during pregnancy, and exposure to passive smoking during pregnancy, 25(OH)D concentrations showed an inverse association with the risk of acquiring acute nasopharyngitis by 6 months of age (P for trend=0.0004).ConclusionThe results show that 89.9% of healthy newborns in Korea are born with vitamin D insufficiency or deficiency (55.6% and 34.3%, respectively). Cord blood vitamin D insufficiency or deficiency in healthy neonates is associated with an increased risk of acute nasopharyngitis by 6 months of age. More time spent outdoors and more intensified vitamin D supplementation for pregnant women may be needed to prevent the onset of acute nasopharyngitis in infants
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