We examined the effects of nutrient availability and turbidity on phytoplankton biomass over 9 years in Gwanyang Bay, Korea, which is an anthropogenically polluted and complex estuary. While dredging ...and reclamation shaped geochemical features, river discharge with low-turbidity water and sewage treatment plants contributed to nutrient loading. The replete levels of nutrients and short water-residence time suggest the inapplicability of the washout theory, whereas the presence of NH4+ suppressed the growth of phytoplankton. A reduction in the river discharge caused a concomitant decline in the loading and dilution of suspended particles. All these features led to an increase in SPM, light limitation, and NH4+ concentration. GLM estimates revealed negative effects of NH4+ and SPM on chlorophyll a over 9 years while SEM verified synergistic effects of NH4+ and SPM compared with positive effects of NO2 + NO3−. Our findings provide new insights into phytoplankton bloom dynamics in Gwangyang Bay.
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•Nutrient availability and turbidity control phytoplankton biomass in estuaries.•The temporal variation of phytoplankton biomass over 9 years showed a gradual decrease in chlorophyll a in anthropogenically polluted and complex Gwangyang Bay.•Reduced river discharge caused an increase in suspended particulate matter, light limitation, and NH4+ concentrations.•Generalized linear models and a structural equation model verified synergistic effects of NH4+ and SPM drove the decrease in chlorophyll a.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Ni/SiO2 catalysts were prepared from aqueous Ni(NO3)2 solutions by the precipitation method using Na2SiO3.•This is a simple but efficient method to prepare well-dispersed NiO on ...silica.•The prepared catalysts were active for two model reactions, benzene hydrogenation and CO methanation.
Ni/SiO2 catalysts with high Ni content were prepared from aqueous Ni(NO3)2 solutions by the precipitation method using Na2SiO3 as a silica precursor and precipitant. This is a simple but efficient method to prepare well-dispersed NiO on silica, which can be further transformed to Ni/SiO2 through an additional reduction process. Various techniques such as nitrogen physisorption, X-ray diffraction (XRD), temperature-programmed reduction with hydrogen (H2-TPR), hydrogen chemisorption, high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) were employed to characterize the catalysts. The prepared catalysts were applied to two model reactions, benzene hydrogenation and CO methanation. The catalyst showed significantly enhanced performance for these reactions compared to core-shell Ni@SiO2 catalysts and conventional Ni/SiO2 catalysts prepared by wet impregnation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Ni/SiC and Ni/SiO
2
catalysts prepared by both wet impregnation (WI) and deposition–precipitation (DP) methods were compared for CO and CO
2
methanation. The prepared catalysts were characterized ...using N
2
physisorption, temperature-programmed reduction with H
2
(H
2
-TPR), H
2
chemisorption, pulsed CO
2
chemisorption, temperature-programmed desorption of CO
2
(CO
2
-TPD), transmission electron microscopy, and X-ray diffraction. H
2
-TPR analysis revealed that the catalysts prepared by DP exhibit stronger interaction between the nickel oxides and support than those prepared by WI. The former catalysts exhibit higher Ni dispersions than the latter. The catalytic activities for both reactions over Ni/SiC and Ni/SiO
2
catalysts prepared by WI increase on increasing the Ni content from 10 to 20 wt%. The Ni/SiC catalyst prepared by DP shows higher catalytic activity for CO and CO
2
methanation than that of the Ni/SiC catalyst prepared by WI. Furthermore, it exhibits the highest catalytic activity for CO methanation among the tested catalysts. The high Ni dispersion achieved by the DP method and the high thermal conductivity enabled by SiC are beneficial for both CO and CO
2
methanation.
Angiogenesis, the process by which new blood vessels are recruited to existing ones, is essential for tumor development. Insulin‐like growth factor (IGF) binding protein‐3 (IGFBP‐3), which modulates ...bioavailability of IGF, has been studied for its potential role in angiogenesis during tissue regeneration and cancer development. In this study, we assessed the role of IGFBP‐3 in tumor angiogenesis in head and neck squamous cell carcinoma (HNSCC) and human umbilical vein endothelial cells (HUVECs) using adenoviral (Ad‐BP3) and recombinant (rBP3) IGFBP‐3. Using an in vivo orthotopic tongue tumor model, we confirmed that both Ad‐BP3 and rBP3 suppress the growth of UMSCC38 HNSCC cells in vivo. Ad‐BP3 inhibited vascularization in tongue tumors and chorio‐allantoic membrane, and suppressed angiogenesis‐stimulating activities in UMSCC38 cells. In HUVECs, Ad‐BP3 decreased migration, invasion, and tube formation. rBP3 also suppressed production of vascular endothelial growth factor (VEGF) in HUVECs and UMSCC38 cells. IGFBP‐3‐GGG, a mutant IGFBP‐3 with loss of IGF binding capacity, suppressed VEGF production. In addition, we found that IGFBP‐3 suppressed VEGF expression, even in mouse embryonic fibroblasts from an IGF‐1R‐null mouse. Finally, we demonstrated that IGFBP‐3‐GGG inhibits tumor angiogenesis and growth to the same degree as wild‐type IGFBP‐3. Taken together, these results support the hypothesis that IGFBP‐3 has anti‐angiogenic activity in HNSCC, at least in part due to IGF‐independent suppression of VEGF production from vascular endothelial cells and cancer cells. (Cancer Sci 2012; 103: 1259–1266)
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The transmembrane nerve injury-induced protein 1 (Ninjurin1 or Ninj1) is involved in progressing inflammatory diseases. In this study, we aimed to investigate a novel function of Ninj1 in pulmonary ...fibrosis. We found that the expression of Ninj1 in a patient cohort was upregulated in the lung specimens of idiopathic pulmonary fibrosis patients as well as mice with bleomycin-induced pulmonary fibrosis. In addition, the BLM-injected Ninj1 KO mice exhibited a mild fibrotic phenotype, as compared to WT mice. Therefore, we hypothesized that Ninj1 would play an important role in the development of pulmonary fibrosis. We discovered that Ninj1 expression increased in BLM-treated macrophages and alveolar epithelial cells (AECs). Interestingly, macrophages bound to BLM-treated AECs were activated. However, when Ninj1 expression was suppressed in either of AECs or macrophages, contact-dependent activation of macrophages with AECs was diminished. In addition, introduction of recombinant mouse Ninj1
to macrophages triggered an inflammatory response, but did not stimulate Ninj1-deficient macrophages. In conclusion, we propose that Ninj1 may contribute to activation of macrophages by enhancing interaction with AECs having elevated Ninj1 expression due to injury-inducing stimuli. Consequently, Ninj1 may be involved in the development of pulmonary fibrosis by enhancing inflammatory response of macrophages.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Despite the crucial role of endothelial progenitor cells (EPCs) in vascular regeneration, the specific interactions between EPCs and hematopoietic cells remain unclear.
In EPC colony forming assays, ...we first demonstrated that the formation of EPC colonies was drastically increased in the coculture of CD34+ and CD34- cells, and determined the optimal concentrations of CD34+ cells and CD34- cells for spindle-shaped EPC differentiation.
Functionally, the coculture of CD34+ and CD34- cells resulted in a significant enhancement of adhesion, tube formation, and migration capacity compared with culture of CD34+ cells alone. Furthermore, blood flow recovery and capillary formation were remarkably increased by the coculture of CD34+ and CD34- cells in a murine hind-limb ischemia model. To elucidate further the role of hematopoietic cells in EPC differentiation, we isolated different populations of hematopoietic cells. T lymphocytes (CD3+) markedly accelerated the early EPC status of CD34+ cells, while macrophages (CD11b+) or megakaryocytes (CD41+) specifically promoted large EPC colonies.
Our results suggest that specific populations of hematopoietic cells play a role in the EPC differentiation of CD34+ cells, a finding that may aid in the development of a novel cell therapy strategy to overcome the quantitative and qualitative limitations of EPC therapy.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A HC(NH
2
)
2
PbI
3
solar cell of perovskite structure based on TiO
2
nanohelices has been developed. Well-aligned helical TiO
2
arrays of different pitch (
p
) and radius (
r
), helix-1 (
p
/2 = 118 ...nm,
r
= 42 nm), helix-2 (
p
/2 = 353 nm,
r
= 88 nm) and helix-3 (
p
/2 = 468 nm,
r
= 122 nm), were grown on fluorine-doped tin oxide (FTO) glass by oblique-angle electron beam evaporation. HC(NH
2
)
2
PbI
3
perovskite was deposited on the TiO
2
nanohelices by a two-step dipping method. Helix-1 showed higher short-circuit current density (
J
SC
), whereas helix-3 exhibited slightly higher open-circuit voltage (
V
OC
). HC(NH
2
)
2
PbI
3
perovskite combined with helix-1 demonstrated an average power conversion efficiency of 12.03 ± 0.07% due to its higher
J
SC
compared to helix-2 and helix-3. The higher
J
SC
of helix-1 could be attributed to its greater light scattering efficiency and higher absorbed photon-to-current conversion efficiency. In addition, despite having the longest pathway structure, helix-1 showed rapid electron diffusion, attributed to its higher charge injection efficiency due to the larger contact area between perovskite and TiO
2
. We have established that fine tuning of the interface between perovskite and the electron-injecting oxide is a crucial factor in achieving a perovskite solar cell of high performance.
A HC(NH
2
)
2
PbI
3
perovskite solar cell based on TiO
2
nanohelices has been developed.
Bioluminescence imaging is useful for non-invasively monitoring inflammatory reactions associated with disease progression, and since NF-κB is a pivotal transcription factor that alters expressions ...of inflammatory genes, we generated novel NF-κB luciferase reporter (NF-κB-Luc) mice to understand the dynamics of inflammatory responses in whole body, and also in various type of cells by crossing NF-κB-Luc mice with cell-type specific Cre expressing mice (NF-κB-Luc:Cre). Bioluminescence intensity was significantly increased in NF-κB-Luc (NKL) mice exposed to inflammatory stimuli (PMA or LPS). Crossing NF-κB-Luc mice with Alb-cre mice or Lyz-cre mice generated NF-κB-Luc:Alb (NKLA) and NF-κB-Luc:Lyz2 (NKLL) mice, respectively. NKLA and NKLL mice showed enhanced bioluminescence in liver and macrophages, respectively. To confirm that our reporter mice could be utilized for the non-invasive monitoring of inflammation in preclinical models, we conducted a DSS-induced colitis model and a CDAHFD-induced NASH model in our reporter mice. In both models, our reporter mice reflected the development of these diseases over time. In conclusion, we believe that our novel reporter mouse can be utilized as a non-invasive monitoring platform for inflammatory diseases.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Phytoestrogen intake is known to be beneficial to decrease breast cancer incidence and progression. But its molecular mechanisms of action are still unknown. The present study aimed to examine the ...effect of apigenin on proliferation and apoptosis in HER2-expressing breast cancer cells. In our experiments, apigenin inhibited the proliferation of BT-474 cells in a dose- and time-dependent manner. Apigenin also inhibited clonogenic survival (anchorage-dependent and -independent) of BT-474 cells in a dose-dependent manner. These growth inhibitions were accompanied with an increase in sub-G0/G1 apoptotic populations. Apigenin-induced extrinsic a caspase-dependent apoptosis up-regulating the levels of cleaved caspase-8 and cleaved caspase-3, and inducing the cleavage of poly (ADP-ribose) polymerase (PARP). Whereas, apigenin did not induce apoptosis via intrinsic mitochondrial apoptosis pathway since this compound did not decrease mitochondrial membrane potential without affecting the levels of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (BAX). Apigenin reduced the expression of phospho-JAK1, phospho-JAK2 and phospho-STAT3 and decreased signal transducer and activator of transcription 3 (STAT3) dependent luciferase reporter gene activity in BT-474 cells. Apigenin inhibited CoCl2-induced VEGF secretion and decreased the nuclear translocation of STAT3. Our study indicates that apigenin induces apoptosis through inhibition of STAT3 signalling and could serve as a useful compound to prevent or treat HER2-overexpressing breast cancer.
Remote epitaxy enables to fabricate flexible GaN micro-LED sticker releasable from wafer.
There have been rapidly increasing demands for flexible lighting apparatus, and micrometer-scale ...light-emitting diodes (LEDs) are regarded as one of the promising lighting sources for deformable device applications. Herein, we demonstrate a method of creating a deformable LED, based on remote heteroepitaxy of GaN microrod (MR)
p
-
n
junction arrays on
c
-Al
2
O
3
wafer across graphene. The use of graphene allows the transfer of MR LED arrays onto a copper plate, and spatially separate MR arrays offer ideal device geometry suitable for deformable LED in various shapes without serious device performance degradation. Moreover, remote heteroepitaxy also allows the wafer to be reused, allowing reproducible production of MR LEDs using a single substrate without noticeable device degradation. The remote heteroepitaxial relation is determined by high-resolution scanning transmission electron microscopy, and the density functional theory simulations clarify how the remote heteroepitaxy is made possible through graphene.
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