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•Isomeric configurations lead to varied binding energies and adsorption affinities.•Meta-substitution to COOH enhances nucleophilic reaction for favorable adsorption.•Substitution at ...Ortho/Para positions causes difference due to steric hindrance.•Adsorption affinity mirrors corrosion inhibition efficiency during CMP process.•Nicotinic acid, meta-substitution, attained the highest anti-corrosion at 88.57 %.
We systematically investigate the adsorption behavior and corrosion inhibition efficacy of pyridine carboxylic acid isomers (Picolinic, Nicotinic, Isonicotinic acids) on Cu films in alkaline conditions. By integrating theoretical analyses, density functional theory (DFT) calculations, and experimental techniques, we demonstrate the underlying mechanisms governing the adsorption affinities and corrosion inhibition properties of these isomers. Our results show that Nicotinic acid exhibits the highest adsorption affinity and corrosion inhibition efficiency on Cu films, attributed to its favorable electronic and steric properties that enhance nucleophilic interaction and electron donation capabilities. On the other hand, Picolinic acid hindered by steric effects shows the lowest adsorption affinity and inhibition efficiency. The electrochemical studies confirm that Nicotinic acid significantly lowers the corrosion current density and enhances the polarization resistance, offering superior protection against corrosion. Furthermore, the chemical and electrochemical interactions between the inhibitors and Cu films are detailed, with insights into the modification of the Cu surface’s electric structure and the formation of protective layers against oxidation. Our research contributes important insights for the development and use of effective corrosion inhibitors for Cu, especially in semiconductor manufacturing and other industries, highlighting the importance of an isomer’s molecular structure in its ability to adsorb and prevent corrosion.
Although the insurance industry has a significant economic role, few theoretical studies link insurance with the overlapping generations economy. This study suggests a new overlapping generations ...model that includes insurance in the agents' economic decisions under the uncertainty of financial losses. In this insurance model, we derive risk-averse workers' optimal insurance purchases and consumption based on the insurance-adjusted valuations, which are the present value of the income streams minus insurance premiums paid in the future. The theoretical equilibrium model predicts capital returns, wealth, labor supply, etc. Our findings show that higher workforce and technological progress increase private insurance demand and reduce the capital-output ratio, and higher losses as a fraction of output increase social insurance demand and reduce the capital-output ratio via numerical comparative statics.
•This study suggests an OLG model that includes insurance purchases in the agents’ decision-making under the uncertainty of financial losses.•We derive risk-averse workers’ optimal insurance purchases and consumption based on the insurance-adjusted valuation.•We implement comparative statics numerically via the workforce growth, technological progress, and losses to output ratio to predict capital returns and economic variables.
Due to the difficulty of performing uniaxial tensile testing, the strengths of graphene and its grain boundaries have been measured in experiments by nanoindentation testing. From a series of ...molecular dynamics simulations, we find that the strength measured in uniaxial simulation and the strength estimated from the nanoindentation fracture force can differ significantly. Fracture in tensile loading occurs simultaneously with the onset of crack nucleation near 5-7 defects, while the graphene sheets often sustain the indentation loads after the crack initiation because the sharply concentrated stress near the tip does not give rise to enough driving force for further crack propagation. Due to the concentrated stress, strength estimation is sensitive to the indenter tip position along the grain boundaries. Also, it approaches the strength of pristine graphene if the tip is located slightly away from the grain boundary line. Our findings reveal the limitations of nanoindentation testing in quantifying the strength of graphene, and show that the loading-mode-specific failure mechanism must be taken into account in designing reliable devices from graphene and other technologically important 2D materials.
The strength of pristine graphene and its grain boundaries (GBs) are mainly measured by nanoindentation with a spherical tip due to the difficulty of conducting uniaxial tensile tests. However, we ...recently showed that the fracture forces from the spherical indenter cannot be directly mapped onto the uniaxial strength. In this paper, employing a series of molecular dynamics simulations combined with a fracture mechanics analysis, we demonstrate that the fracture force from cylindrical indenters can be directly mapped onto the strength of graphene under uniaxial tension. Under indentation with cylindrical tips or uniaxial tension, the rupture of graphene sheets that have GBs with a low-tilt angle occurs simultaneously with the onset of crack nucleation at the GBs. On the contrary, when indented by a spherical indenter tip, the graphene sheets sustain the indentation loads until the crack size becomes comparable to the tip radius. Furthermore, the results show that estimating the strength with a cylindrical indenter is not very sensitive to the indentation site as well as angular misalignments that can be caused by human error or the limitations of the apparatus. Our work presents the feasibility of obtaining the tensile strength from nanoindentation experiments, which may suggest a new standard to measure the tensile strength of graphene and related two-dimensional materials.
Anemia of chronic disease (ACD) refers to hypoproliferative anemia in the context of acute or chronic activation of the immune system. There is a paucity of prospective data addressing the risk ...factors for ACD development. An association between common chronic diseases and ACD was examined cross-sectionally and longitudinally.
A cohort of 265,459 healthy participants without ACD at baseline were prospectively followed annually or biennially.
During average follow-up period of 62 months, 4,906 participants developed ACD (incidence rate 3.58 per 1000 person-years). Multivariable-adjusted hazard ratio (HR) 95% confidence interval (CI) for incident ACD comparing estimated glomerular filtration rate 30-60 and < 30 vs. ≥ 60 ml/min/1.73 m2 were 3.93 3.18-4.85 and 39.11 18.50-82.69; HRs 95% CI for ACD comparing prediabetes and diabetes vs. normal were 1.19 1.12-1.27 and 2.46 2.14-2.84, respectively. HRs 95% CI for incident ACD comparing body-mass-index (BMI) of < 18.5, 23-24.9 and ≥ 25 vs. 18.5-22.9 kg/m2 were 0.89 0.78-1.00, 0.89 0.80-0.99 and 0.78 0.66-0.91, respectively. HRs 95% CI for incident ACD comparing prehypertension and hypertension vs. normal were 0.79 0.73-0.86 and 1.10 0.99-1.23, respectively. Metabolic syndrome, hypertension, chronic liver disease, and chronic obstructive pulmonary disease were not associated with incident ACD.
The severity of chronic kidney disease and diabetic status were independently associated with an increased incidence of ACD, whereas prehypertension and an increasing BMI were significantly associated with decreased risk of ACD.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
E6 oncoprotein derived from high-risk human papillomavirus (HPV) drives the development of cervical cancer through p53 degradation. Because cervical cancer therapies to inactivate HPV or E6 protein ...are not available, alternative strategies are required. Here, we show that HPV-mediated nuclear export of human heterochromatin protein 1γ (HP1γ) reduces the stability of p53 through UBE2L3-mediated p53 polyubiquitination during cervical cancer progression. In general, HP1 plays a key role in heterochromatin formation and transcription in the nucleus. However, our immunostaining data showed that the majority of HP1γ is localized in the cytoplasm in HPV-mediated cervical cancer. We found that HPV E6 protein drives unusual nuclear export of HP1γ through the interaction between the NES sequence of HP1γ and exportin-1. The mutation of the NES sequence in HP1γ led to nuclear retention of HP1γ and reduced cervical cancer cell growth and tumor generation. We further discovered that HP1γ directly suppresses the expression of UBE2L3 which drives E6-mediated proteasomal degradation of p53 in cervical cancer. Downregulation of UBE2L3 by overexpression of HP1γ suppressed UBE2L3-dependent p53 degradation-promoting apoptosis of cervical cancer cells. Our findings propose a useful strategy to overcome p53 degradation in cervical cancer through the blockage of nuclear export of HP1γ.
This study provides a view of the primary aerodynamic design of Hyperloop pod considering the influence of tail shape and length on aerodynamic forces (drag and lift) and flow behaviors (pressure, ...Mach number, and temperature). Numerical simulations are performed considering two tail shapes (i.e., upward and downward tails) and five lengths of the downward tail (i.e., 1.725, 3.45, 6.9, 13.35, and 13.8 m). The dynamic overset mesh method utilizing polyhedral meshes is applied to simulate the movement of the pod. A simplified three-dimensional model is simulated using the unsteady Reynolds-averaged Navier–Stokes shear stress transport k–ω turbulence model, compressible ideal gas, and a pod speed of 300 m/s. The results indicate that the two tail shapes only have a minor effect on aerodynamic drag (i.e., the difference between the upward and downward tails is only 0.75%), generating two tendencies of aerodynamic lift (i.e., the upward tail provides negative lift, and the downward tail yields positive lift). When tail length of the pod increases, it effectively reduces the aerodynamic drag (approximately 7%) and pressure on the pod surface. Meanwhile, the variation of lift observes an intriguing tendency (which the lift is maximum at 6.9 m – tail length). When the tail length is increased over 6.9 m, the lift starts to reduce; however, the lift is increased when the tail is shorter than 6.9 m. The flow fields around and behind the pod tail are significantly affected by the change in tail length, particularly when considering the intensity and generation of the first OS. The highest intensity of the first OS is attained when the tail length is 6.9 m. The increase in tail length considerably reduces the pressure on the pod but slightly affects the pod temperature (exhibiting a maximum difference of 0.4% among the five cases).
•The directional optimization of magnetization was considered to enhance output power.•The harvester generated 39.2 mW as 2.13 to 784 times enhanced power.•The autonomous IoT and IIoT sensor systems ...were successfully constructed.•This method can significantly improve the energy harvesting using a magnetic field.
Unlike previous piezoelectric energy harvesters that generate electrical energy from a magnetic field according to the magnetic strength or magnetostrictive material, the proposed method achieves significant power enhancement using directional optimization of magnetization. This method can serve as a ubiquitous autonomous energy source that converts a magnetic field into usable electrical energy in a wireless sensor network for an (Industrial) Internet of Things (IIoT). The key approach in the proposed model is to increase of the Lorentz force by vertically adjusting the magnetic flux direction of a power cable and the magnetic direction of a tip magnet. In the simulation, a 3592 times higher y-axis Lorentz force was obtained in the vertical pole array, which resulted in about a 1.6 times higher output voltage. Then, we experimentally compared the electrical output performance of six different types of pole array according to the size and direction of the tip magnet. In a one-tip magnet (10 × 10 × 10 mm3), the output power values were 2.34 mW (Vertical) and 1.23 mW (Horizontal) at 8 kΩ matching impedance. For two-tip magnets (20 × 10 × 10 mm3), the output power values of the harvester were 39.2 mW (Planar-Vertical), 18.4 mW (Orthogonal-Vertical), 8.64 mW (Planar-Horizontal), and 0.05 mW (Orthogonal-Horizontal) at 5 kΩ matching impedance. It was found that the power generation differed by 2.13 to 784 times. With this method of power enhancement using multi-disciplinary research, we successfully constructed autonomous IoT and IIoT sensor systems for smart homes, smart buildings and smart factories.
Aberrant glutathione or Ca(2+) homeostasis due to oxidative stress is associated with the pathogenesis of neurodegenerative disorders. The Ca(2+)-permeable transient receptor potential cation (TRPC) ...channel is predominantly expressed in the brain, which is sensitive to oxidative stress. However, the role of the TRPC channel in neurodegeneration is not known. Here, we report a mechanism of TRPC5 activation by oxidants and the effect of glutathionylated TRPC5 on striatal neurons in Huntington's disease. Intracellular oxidized glutathione leads to TRPC5 activation via TRPC5 S-glutathionylation at Cys176/Cys178 residues. The oxidized glutathione-activated TRPC5-like current results in a sustained increase in cytosolic Ca(2+), activated calmodulin-dependent protein kinase and the calpain-caspase pathway, ultimately inducing striatal neuronal cell death. We observed an abnormal glutathione pool indicative of an oxidized state in the striatum of Huntington's disease transgenic (YAC128) mice. Increased levels of endogenous TRPC5 S-glutathionylation were observed in the striatum in both transgenic mice and patients with Huntington's disease. Both knockdown and inhibition of TRPC5 significantly attenuated oxidation-induced striatal neuronal cell death. Moreover, a TRPC5 blocker improved rearing behaviour in Huntington's disease transgenic mice and motor behavioural symptoms in littermate control mice by increasing striatal neuron survival. Notably, low levels of TRPC1 increased the formation of TRPC5 homotetramer, a highly Ca(2+)-permeable channel, and stimulated Ca(2+)-dependent apoptosis in Huntington's disease cells (STHdh(Q111/111)). Taken together, these novel findings indicate that increased TRPC5 S-glutathionylation by oxidative stress and decreased TRPC1 expression contribute to neuronal damage in the striatum and may underlie neurodegeneration in Huntington's disease.
With rapid changes in lifestyle patterns and recent technological advancements, there is an increasing demand for efficient, convenient, and eco-friendly transportation systems. The Hyperloop system, ...which is a tube–train system, was introduced with the aim of catering to the demand for improved transportation facilities. The primary factors of the Hyperloop system such as the point of departure (pod), standstill, and transfer are directly dependent on the change in the cross-sectional area of the tube such as stations. In this study, the effects of sudden expansion and contraction were analyzed though numerical simulations with respect to the blockage ratio (BR), expansion ratio (ER), and contraction ratios (CR). Furthermore, the propagation Mach number and magnitude of pressure waves were predicted through theoretical consideration. Under sudden expansion and contraction of tube, the first leading shock wave (LSW1), reflected expansion wave (REW), second leading shock wave (LSW2), reflected shock wave (RSW), and third leading shock wave (LSW3) are generated in this system. The propagation Mach number and pressure magnitude of LSW1 increase with an increase in the BR. The Mach number of REW decreases with an increase in the BR. The propagation Mach number of LSW2 increases with the BR and with a decrease in the ER owing to the pressure behind the shock wave. The propagation Mach number of RSW decreases with an increase in the BR and with a decrease in the CR, and that of LSW3 increases with an increase in the BR and with a decrease in the CR. The drag coefficient decreases when REW reaches the pod because the expansion wave decreases the pressure of flow field. Owing to the similar minimum drag coefficient, the difference of drag coefficient increases with an increase in the BR. In this study, the predicted Mach number and pressure magnitude under quasi-one-dimensional assumption are in good agreement with the simulation results. Therefore, this study can aid the design of expanded and contracted zones considering the formation of the shock wave.
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