AMINO ACID REMOVAL DURING HEMODIALYSIS OF PATI-ENTS WHO HAD UNDERGONE INTRADIALYTIC PAR-ENTERAL NUTRITION.

Hemodialysis removes solutes uniformly according to their molecular weight. During each hemodialysis session, 6–8 g of amino acids are reportedly removed into the dialysate. Little is known about the amount of amino acids removed from those who have undergone intradialytic parenteral nutrition (IDPN). Objective: We measured amino acid amounts prospectively during hemodialysis treatment. Methods: We used 200 ml of 7.2% amino acid solution (KidminTM), 200 ml of 50% glucose, and 20% of lipid emulsion as IDPN fluid. Blood samples were collected at the beginning and end of each session. The dialysate portion was also collected. Results: Six patients were included in this study after providing written informed consent. The amount of amino acids removed during hemodialysis sessions was calculated as 9.1±1.4 g, which was less than that infused as IDPN. The profiles of the removed amino acids showed that the amount removed was less than that within IDPN. However, for tyrosine and alanine, hemodialysis treatment removed more amino acids than that infused as IDPN, as well as amino acids that were not IDPN solution constituents. During a 2-week follow-up period, no significant change in amino acid profiles was observed. Conclusions: IDPN entirely supplemented the removed amino acids, although some amino acids were not restored

Mechanistic Study of Silane Alcoholysis Reactions with Self-Assembled Monolayer-Functionalized Gold Nanoparticle Catalysts

The self-assembled monolayer (SAM)-modified metallic nanoparticles (MNPs) often exhibit improved chemoselectivity in various catalytic reactions by controlling the reactants’ orientations adsorbed in the SAM; however, there have been a few examples showing that the reaction rate, i.e., catalytic activity, is enhanced by the SAM-modification of MNP catalysts. The critical parameters that affect the catalytic activity, such as the supports, nanoparticle size, and molecular structures of the SAM components, remain uninvestigated in these sporadic literature precedents. Here, we report the mechanistic investigation on the effects of those parameters on the catalytic activity of alkanethiolate SAM-functionalized gold nanoparticles (AuNPs) toward silane alcoholysis reactions. The evaluation of the catalytic reaction over two-dimensionally arrayed dodecanethiolate SAM-functionalized AuNPs with different supports revealed the electronic interactions between AuNPs and the supports contributing to the rate enhancement. Additionally, an unprecedented size effect appeared—the AuNP with a 20 nm radius showed higher catalytic activity than those at 10 and 40 nm. Infrared reflection–absorption spectroscopy revealed that the conformational change of alkyl chains of the SAM affects the entrapment of reactants and products inside the SAM, and therefore brings about the acceleration effect. These findings provide a guideline for further applying the SAM-functionalization technique to stereoselective organic transformations with designer MNP catalysts

MYU, a Target lncRNA for Wnt/c-Myc Signaling, Mediates Induction of CDK6 to Promote Cell Cycle Progression

Aberrant activation of Wnt/β-catenin signaling is a major driving force in colon cancer. Wnt/β-catenin signaling induces the expression of the transcription factor c-Myc, leading to cell proliferation and tumorigenesis. c-Myc regulates multiple biological processes through its ability to directly modulate gene expression. Here, we identify a direct target of c-Myc, termed MYU, and show that MYU is upregulated in most colon cancers and required for the tumorigenicity of colon cancer cells. Furthermore, we demonstrate that MYU associates with the RNA binding protein hnRNP-K to stabilize CDK6 expression and thereby promotes the G1-S transition of the cell cycle. These results suggest that the MYU/hnRNP-K/CDK6 pathway functions downstream of Wnt/c-Myc signaling and plays a critical role in the proliferation and tumorigenicity of colon cancer cells

Anion-Exchange Membrane Fuel Cells with Improved CO₂ Tolerance: Impact of Chemically Induced Bicarbonate Ion Consumption

Over the last few decades, because of the significant development of anion exchange membranes, increasing efforts have been devoted the realization of anion exchange membrane fuel cells (AEMFCs) that operate with the supply of hydrogen generated on-site. In this paper, ammonia was selected as a hydrogen source, following which the effect of conceivable impurities, unreacted NH₃ and atmospheric CO₂, on the performance of AEMFCs was established. As expected, we show that these impurities worsen the performance of AEMFCs significantly. Furthermore, with the help of in situ attenuated total reflection infrared (ATR-IR) spectroscopy, it was revealed that the degradation of the cell performance was primarily due to the inhibition of the hydrogen oxidation reaction (HOR). This is attributed to the active site occupation by CO-related adspecies derived from (bi)­carbonate adspecies. Interestingly, this degradation in the HOR activity is suppressed in the presence of both NH₃ and HCO₃^– because of the bicarbonate ion consumption reaction induced by the existence of NH₃. Further analysis using in situ ATR-IR and electrochemical methods revealed that the poisonous CO-related adspecies were completely removed under NH₃–HCO₃^– conditions, accompanied by the improvement in HOR activity. Finally, a fuel cell test was conducted by using the practical AEMFC with the supply of NH₃-contained H₂ gas to the anode and ambient air to the cathode. The result confirmed the validity of this positive effect of NH₃–HCO₃^– coexistence on CO₂-tolerence of AEMFCs. The cell performance achieved nearly 95% of that without any impurity in the fuels. These results clearly show the impact of the chemically induced bicarbonate ion consumption reaction on the realization of highly CO₂-tolerent AEMFCs