RAS proteins play critical roles in various cellular processes, including growth and transformation. RAS proteins are subjected to protein stability regulation via the Wnt/β‐catenin pathway, and ...glycogen synthase kinase 3 beta (GSK3β) is a key player for the phosphorylation‐dependent RAS degradation through proteasomes. GSK3β‐mediated RAS degradation does not occur in cells that express a nondegradable mutant (MT) β‐catenin. Here, we show that β‐catenin directly interacts with RAS at the α‐interface region that contains the GSK3β phosphorylation sites, threonine 144 and threonine 148 residues. Exposure of these sites by prior β‐catenin degradation is required for RAS degradation. The introduction of a peptide that blocks the β‐catenin‐RAS interaction by binding to β‐catenin rescues the GSK3β‐mediated RAS degradation in colorectal cancer (CRC) cells that express MT β‐catenin. The coregulation of β‐catenin and RAS stabilities by the modulation of their interaction provides a mechanism for Wnt/β‐catenin and RAS‐ERK pathway cross‐talk and the synergistic transformation of CRC by both APC and KRAS mutations.
Synopsis
GSK3β promotes phosphorylation‐ and polyubiquitination‐dependent proteasomal RAS degradation. β‐Catenin directly interacts with RAS, thereby preventing GSK3β‐dependent phosphorylation and degradation, defining the basis for the synergistic effect of β‐catenin and RAS on cancer growth.
β‐Catenin directly interacts with RAS at the α‐interface that contains GSK3β phosphorylation sites.
β‐Catenin degradation is required for subsequent GSK3β‐mediated RAS degradation.
Targeting both β‐catenin and RAS for degradation is a potential approach against colorectal cancer.
GSK3β promotes phosphorylation‐ and polyubiquitination‐dependent proteasomal RAS degradation. β‐Catenin directly interacts with RAS, thereby preventing GSK3β‐dependent phosphorylation and degradation, defining the basis for the synergistic effect of β‐catenin and RAS on cancer growth.
To significantly increase the amount of exsolved particles, the complete phase reconstruction from simple perovskite to Ruddlesden-Popper (R-P) perovskite is greatly desirable. However, a ...comprehensive understanding of key parameters affecting the phase reconstruction to R-P perovskite is still unexplored. Herein, we propose the Gibbs free energy for oxygen vacancy formation in Pr
(Ba/Sr)
TO
(T = Mn, Fe, Co, and Ni) as the important factor in determining the type of phase reconstruction. Furthermore, using in-situ temperature & environment-controlled X-ray diffraction measurements, we report the phase diagram and optimum 'x' range required for the complete phase reconstruction to R-P perovskite in Pr
Ba
Sr
FeO
system. Among the Pr
Ba
Sr
FeO
, (Pr
Ba
Sr
)
FeO
- Fe metal demonstrates the smallest size of exsolved Fe metal particles when the phase reconstruction occurs under reducing condition. The exsolved nano-Fe metal particles exhibit high particle density and are well-distributed on the perovskite surface, showing great catalytic activity in fuel cell and syngas production.
The association between sarcopenia and cardiovascular disease (CVD) in elderly people has not been adequately assessed. The aim of this study was to investigate whether CVD is more prevalent in ...subjects with sarcopenia independent of other well-established cardiovascular risk factors in older Korean adults.
This study utilized the representative Korean population data from the Korea National Health and Nutrition Examination Survey (KNHANES) which was conducted in 2009. Subjects older than 65 years of age with appendicular skeletal muscle mass (ASM) determined by dual energy X-ray absorptiometry were selected. The prevalence of sarcopenia in the older Korean adults was investigated, and it was determined whether sarcopenia is associated with CVD independent of other well-known risk factors.
1,578 subjects aged 65 years and older with the data for ASM were selected, and the overall prevalence of sarcopenia was 30.3% in men and 29.3% in women. Most of the risk factors for CVD such as age, waist circumference, body mass index, fasting plasma glucose and total cholesterol showed significant negative correlations with the ratio between appendicular skeletal muscle mass and body weight. Multiple logistic regression analysis demonstrated that sarcopenia was associated with CVD independent of other well-documented risk factors, renal function and medications (OR, 1.768; 95% CI, 1.075-2.909, P = 0.025).
Sarcopenia was associated with the presence of CVD independent of other cardiovascular risk factors after adjusting renal function and medications.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
1,3-propanediol (1,3-PDO) is the most widely studied value-added product that can be produced by feeding glycerol to bacteria, including Lactobacillus sp. However, previous research reported that L. ...reuteri only produced small amounts and had low productivity of 1,3-PDO. It is urgent to develop procedures that improve the production and productivity of 1,3-PDO.
We identified a novel L. reuteri CH53 isolate that efficiently converted glycerol into 1,3-PDO, and performed batch co-fermentation with glycerol and glucose to evaluate its production of 1,3-PDO and other products. We optimized the fermentation conditions and nitrogen sources to increase the productivity. Fed-batch fermentation using corn steep liquor (CSL) as a replacement for beef extract led to 1,3-PDO production (68.32 ± 0.84 g/L) and productivity (1.27 ± 0.02 g/L/h) at optimized conditions (unaerated and 100 rpm). When CSL was used as an alternative nitrogen source, the activity of the vitamin B12-dependent glycerol dehydratase (dhaB) and 1,3-propanediol oxidoreductase (dhaT) increased. Also, the productivity and yield of 1,3-PDO increased as well. These results showed the highest productivity in Lactobacillus species. In addition, hurdle to 1,3-PDO production in this strain were identified via analysis of the half-maximal inhibitory concentration for growth (IC50) of numerous substrates and metabolites.
We used CSL as a low-cost nitrogen source to replace beef extract for 1,3-PDO production in L. reuteri CH53. These cells efficiently utilized crude glycerol and CSL to produce 1,3-PDO. This strain has great promise for the production of 1,3-PDO because it is generally recognized as safe (GRAS) and non-pathogenic. Also, this strain has high productivity and high conversion yield.
In this research, the electrochemical biosensor composed of myoglobin (Mb) on molybdenum disulfide nanoparticles (MoS2 NP) encapsulated with graphene oxide (GO) was fabricated for the detection of ...hydrogen peroxide (H2O2). Hybrid structure composed of MoS2 NP and GO (GO@MoS2) was fabricated for the first time to enhance the electrochemical signal of the biosensor. As a sensing material, Mb was introduced to fabricate the biosensor for H2O2 detection. Formation and immobilization of GO@MoS2 was confirmed by transmission electron microscopy, ultraviolet-visible spectroscopy, scanning electron microscopy, and scanning tunneling microscopy. Immobilization of Mb, and electrochemical property of biosensor were investigated by cyclic voltammetry and amperometric i-t measurements. Fabricated biosensor showed the electrochemical signal enhanced redox current as −1.86μA at an oxidation potential and 1.95μA at a reduction potential that were enhanced relative to those of electrode prepared without GO@MoS2. Also, this biosensor showed the reproducibility of electrochemical signal, and retained the property until 9 days from fabrication. Upon addition of H2O2, the biosensor showed enhanced amperometric response current with selectivity relative to that of the biosensor prepared without GO@MoS2. This novel hybrid material-based biosensor can suggest a milestone in the development of a highly sensitive detecting platform for biosensor fabrication with highly sensitive detection of target molecules other than H2O2.
•The electrochemical biosensor composed of the myoglobin on the graphene oxide (GO)-encapsulated molybdenum disulfide nanoparticles (MoS2 NP) was developed for hydrogen peroxide (H2O2) detection.•MoS2 NP were encapsulated by GO (GO@MoS2) for the first time to induce the electrochemical signal enhancement.•Fabricated electrochemical biosensor with GO@MoS2 showed the stability and reproducibility.•Fabricated electrochemical biosensor also showed the enhanced amperometric response current by detection of H2O2.
Neuroscience research has become a national priority for the Korean government. Korean scholars have dedicated interest in the societal ramifications of neurotechnologies; neuroethics is an integral ...component of the Korea Brain Initiative and to the formation of its growing neuroscience community.
Neuroscience research has become a national priority for the Korean government. Korean scholars have dedicated interest in the societal ramifications of neurotechnologies; neuroethics is an integral component of the Korea Brain Initiative and to the formation of its growing neuroscience community.
In this study, the composition-optimized Pd–Cu catalyst for electrochemical N
2
O reduction in highly alkaline solution was prepared by a galvanic displacement method. The atomic ratio of Pd to Cu in ...Pd–Cu bimetallic catalyst, which has been known to be hardly controlled using galvanic displacement, was tailored by varying the concentration of citric acid in galvanic displacement bath. With increasing citric acid concentration, the decreased grain size, characterized by X-ray diffraction, and the increased amount of carbon in Pd–Cu catalyst, measured by energy-dispersive X-ray spectrometry, revealed the incorporation of citric acid into the catalyst, which was attributed to the tunable catalyst composition. The incorporation of citric acid into Pd–Cu deposit restrained the diffusion of Cu from Cu substrate to deposit, leading to decrease in the Cu content in Pd–Cu. The electrocatalytic activity for N
2
O reduction was strongly dependent on the Pd/Cu composition in Pd–Cu catalysts. Among the investigated Pd–Cu catalysts with different compositions, the highest electrocatalytic activity was obtained with Pd
60
Cu
40
with a Tafel slope of 0.096 V dec
−1
. Moreover, the Pd
60
Cu
40
catalyst showed remarkably enhanced mass-specific activity for N
2
O reduction, compared with a commercial Pd/C. The density functional theory (DFT) calculations revealed that the highest N
2
O reduction activity of Pd
60
Cu
40
could be attributed to the facilitation of an adsorption/desorption balance for N
2
O reduction, resulting from the appropriately lowered
d
-band center of catalyst.
Graphic abstract
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•Frequent occurrence of selected fishery antibiotics in coastal aquaculture waters.•Effluent concentration after antibiotic application peaked to several hundred μg/L.•High efficiency ...of HOCl and O3 for eliminating amoxicillin and oxytetracycline.•Reactive halogen species formed in marine matrix enhanced antibiotic degradation.•Sequential use of HOCl and UV254 as an effective option for antibiotic elimination.
The influents and effluents of coastal flow-through aquacultures in Korea were monitored for four selected antibiotics (amoxicillin-AMX, florfenicol-FLO, oxolinic acid-OXO, and oxytetracycline-OTC). A number of 177 samples were obtained from 16 aquaculture facilities for a monitoring period of two years. OTC was detected in 93 samples with a median concentration of 116 ng/L. OXO, FLO, and AMX were also detected in 36, 34, and 22 samples with median concentrations of 90, 44, and 63 ng/L, respectively. After antibiotics were applied to fish tanks, the aquaculture effluents were found to contain antibiotics up to several hundred μg/L, indicating that some control measures are required. Bench-scale experiments showed that chlorine and ozone fully eliminated AMX and OTC but not FLO at ≤2 mg/L of oxidant dosage. Reactive halogen species formed in the marine water matrix enhanced the antibiotic degradation. UV254 most effectively eliminated FLO, achieving 60–70 % elimination at 1000 mJ/cm2 of UV fluence. Sequential use of chlorine followed by UV254 demonstrated significant elimination of all four selected antibiotics. The obtained kinetic information for the reactions of these oxidants and UV with the antibiotics and marine aquaculture water constituents could be useful for designing and optimizing the aquaculture water treatment processes.
Dry reforming of methane (DRM) is a feasible solution to address the reduction of greenhouse gases stipulated by the Paris Climate Agreement, given that it adds value by converting trivial gases, CO2 ...and CH4, simultaneously into useful syngas. However, the conventional Ni catalyst undergoes deactivation due to carbon coking and particle agglomeration. Here we demonstrate a highly efficient and durable DRM catalyst: exsolved Co‐Ni‐Fe ternary alloy nanoparticles on the layered perovskite PrBaMn1.7Co0.1Ni0.2O5+δ produced by topotactic exsolution. This method readily allows the generation of a larger number of exsolved nanoparticles with enhanced catalytic activity above that of Ni monometallic and Co‐Ni bimetallic particles. The enhancement is achieved by the upshift of the d‐band center of Co‐Ni‐Fe relative to those of Co‐Ni and Ni, meaning easier charge donation to the adsorbate. Furthermore, the exsolved catalyst shows exceptional stability, with continuous DRM operation for about 350 hours.
Ternary Co‐Ni‐Fe nanoparticles were produced by topotactic exsolution. Compared bimetallic and monometallic catalysts, the ternary Co‐Ni‐Fe catalyst exhibited enhanced catalytic activity for the dry reforming of methane. DFT calculations indicated the enhanced activity originates from the optimal upshift of the d‐band center of Co‐Ni‐Fe catalyst.
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