Novel Composition of Co-Free LiNi0.875-xMn0.125AlxO2 Cathode Materials.

Ni-rich LiNi1-xMnxO2 cathode materials have attracted widespread interest as promising alternative cathode materials owing to their higher capacity, lower cost, and lower toxicity compared to those of LiCoO2. Therefore, we designed herein a LiNi0.875Mn0.125O2 positive electrode material. However, as the Ni content increases, the materials suffer from an extensive phase transition during the de-lithiation process owing to the low-bond strength of Ni (391.6 kJ mol-1) and Mn (402 kJ mol-1). In this study, Al-doped LiNi0.875-xMn0.125AlxO2 (x= 0, 0.05, 0.1) was synthesized using the coprecipitation method. Al had a higher bond strength (512 kJ mol-1) between oxygen and metal ions compared to that of Ni and Mn ions. Additionally, Al is usually stabilized in the form of Al3+. Therefore, the increased bond strength decreased the electrostatic repulsion with oxygen during the de-lithiation process and prevented cation mixing by stabilizing the Ni ion's valence, thereby resulting in increased structural stability. X-ray diffraction (XRD) was used to characterize their structures and calculate the cation mixing value. The electrochemical properties showed that LiNi0.775Mn0.125Al0.1O2 exhibited the high capacity retention of 97.1% after 30 cycles at 1 C at 55 °C.

Effect of PEDOT:PSS (Poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate) Coating on Nanostructured Cobalt-Free LiNi0.9Mn0.1O2 Layered Oxide Cathode Materials for Lithium-Ion Battery.

Among cobalt-free layered oxides, Li(Ni1-xMnx)O2 (x ≤0.5) (LNMO) shows high reversible capacity, good cycling performance and thermal stability, and has relatively low cost and toxicity due to the absence of cobalt. In this study, we synthesized LNMO cathode materials having a porous fiber shape with primary particles that had an average diameter of about 328 nm. The prepared LNMO has an increased surface area, on which side reactions between the electrolyte and cathode material occur. Therefore, we coated the conductive polymer PEDOT:PSS to solve the problems that may arise. The coated LNMO exhibited a reversible capacity of 128.03 mAh g-1, and 87.1% capacity retention, at a current density of 0.1 C, for up to 30 cycles. It showed a better performance than uncoated LNMO. The process used in this study can be proposed as a new synthesis method for cobalt-free layered oxide materials.

Spray-Dried Amorphous Solid Dispersions of Atorvastatin Calcium for Improved Supersaturation and Oral Bioavailability.

Over the past few decades, the amorphous solid dispersions (ASDs) technique has emerged as a promising strategy to enhance the in vitro/in vivo characteristic of hydrophobic drugs. The low aqueous solubility and poor bioavailability of atorvastatin calcium (ATO), a lipid-lowering drug, present challenges for effective drug delivery. The objective of this work was to improve the aqueous solubility, in vitro dissolution, and oral absorption of ATO with amorphous solid dispersion technique prepared by spray-drying method. The optimized ternary formulation comprising of ATO; hydroxypropyl methylcellulose (HPMC), as a hydrophilic polymer; and sodium lauryl sulfate (SLS), as a surfactant, at a weight ratio of 1/1/0.1, showed significant improvement in aqueous solubility by ~18-fold compared to that of the free drug, and a cumulative release of 94.09% compared to a release of 59.32% of the free drug. Further, physicochemical studies via scanning electron microscopy, differential scanning calorimetry, and powder X-ray diffraction revealed a change from the crystalline state of the free drug to its amorphous state in the ASD. Pharmacokinetic analysis in rats demonstrated 1.68- and 2.39-fold increments in AUC and Cmax, respectively, in the ASD over the free drug. Altogether, hydrophilic carrier-based ASDs prepared by the spray-drying technique represent a promising strategy to improve the biopharmaceutical performance of poorly soluble drugs.

Mitigation of Volume Expansion of Silica Anodes by Porous Titanium Dioxide Coating for Lithium-Ion Batteries.

Silica (SiO2) is one of the most promising anode materials for LIBs due to its high theoretical capacity. However, the huge volume change of silica during the lithiation/delithiation processes is a disadvantage that results in poor electrochemical performance. In this study, the volume change of silica was effectively mitigated by coating the SiO2 anode with porous TiO2. The porous TiO2 has a large amount of internal space that can mitigate the volume expansion of SiO2. To verify the ratio of the volume change, the crosssection of the electrodes was analyzed by scanning electron microscopy (SEM). The ratio of the volume change decreased from 293.5% to 140.7% upon application of the TiO2 coating. Fourier transform infrared analysis suggested that the Ti-O-Si bond helped mitigate the volume expansion. Furthermore, the decrease in the volumetric expansion resulted in good electrochemical performance with increased charge capacity and stable cycle performance. The TiO2 coated SiO2 anode displayed a capacity of 72.33 mA h g-1 at a current density of 98 mA g-1 for up to 50 cycles, which was higher than that of the pristine SiO2 anode (42.29 mA h g-1). The TiO2 coated anode materials are applicable for rechargeable lithium-ion batteries.

Mechanical Analysis of Ceramic/Polymer Composite with Mesh-Type Lightweight Design Using Binder-Jet 3D Printing.

3D printing technology has recently been highlighted as an innovative manufacturing process. Among various 3D printing methods, binder jetting (BJ) 3D printing is particularly known as technology used to produce the complex sand mold quickly for a casting process. However, high manufacturing costs, due to its expensive materials, need to be lowered for more industrial applications of 3D printing. In this study, we investigated mechanical properties of sand molds with a lightweight structure for low material consumption and short process time. Our stress analysis using a computational approach, revealed a structural weak point in the mesh-type lightweight design applied to the 3D-printed ceramic/polymer composite.

Factors associated with menstrual cycle irregularity and menopause.

BACKGROUND: A regular menstrual cycle is an important indicator of a healthy reproductive system. Previous studies reported obesity, stress, and smoking as the factors that are associated with irregular menstruation and early menopause. However, the integrative effects of these modifiable risk factors have not been fully understood. This study aimed to investigate the modifiable risk factors of menstrual cycle irregularity and premature menopause, as well as their individual and combined effects among adult women in Korea. METHOD: This study selected adult women aged 19 years and above who had been included in the 2007-2014 Korean National Health and Nutrition Examination Survey. We used a separate dataset to analyze the risk factors of menstrual cycle irregularity and menopause (pre- and postmenopausal women: n = 4788 and n = 10,697, respectively). Univariate and multiple logistic regression analyses were conducted to evaluate the effects of smoking, drinking, obesity, and perceived level of stress on the menstrual cycle and menopause. Both logit and linear models were used in the analyses of the association between smoking and menopausal age. Equivalized household income, marital status, and educational level were considered as covariates. The modifiable risk factor scores were also calculated to integrate the effect of smoking, drinking, and obesity in the analysis. RESULT: Results showed that smoking status, pack-year, obesity, and perceived level of stress were significantly associated with irregular menstruation among premenopausal women. Especially, women demonstrating > 3 modifiable risk factor scores had 1.7 times higher risk of having irregular menstruation than those who had a 0 score. Meanwhile, early initiation of smoking (≤19 years) and high pack-year (≥5) were also significantly associated with premature menopause among postmenopausal women. CONCLUSION: This study demonstrated that modifiable risk factors, such as smoking, obesity, and stress, were significantly associated with menstrual cycle irregularity. Lifetime smoking was also correlated with early menopause. Our results suggested that healthier lifestyle practices, including, cessation of smoking, weight control, and stress management, were important factors in improving the reproductive health of women throughout life.

Production of sesaminol and antioxidative activity of fermented sesame with Lactobacillus plantarum P8, Lactobacillus acidophilus ATCC 4356, Streptococcus thermophilus S10.

This study was carried out to select the most competent bacterial cultures that could convert sesaminol glycosides to aglycone by ß-glucosidase produced by lactic acid bacteria such as Lactobacillus acidophilus, Lactobacillus plantarum (LP), and Streptococcus thermophilus in sesame fermented at 37°C for 24 h. The pH of fermented sesame was decreased compared to non-fermented controls. The pH of LP was lower than that of the other two during fermentation. Fermented sesame had higher antioxidant activity compared to non-fermented controls during the entire fermentation time. Total phenol content, DPPH free radical scavenging assay, reducing power assay of sesame fermented by LP was the highest compared to the others. In addition, sesame fermented by LP had more bioconversion of sesaminol glycoside to aglycone compared to the others. Therefore, LP was the best bacterial culture of the three strains studied for producing functional fermented sesame for good health.

Eccentric morphology of jailed side-branch ostium after stent crossover in coronary bifurcation lesions: a three-dimensional optical coherence tomographic analysis.

BACKGROUND: Angiographic stenosis of a jailed side-branch ostium is usually observed after a single-stent crossover at coronary bifurcation lesions. However, the stenosis severity is typically overestimated due to the limited information obtained from two-dimensional morphology by angiography. We evaluated the actual stenosis of jailed side-branch ostium using three-dimensional (3D) optical coherence tomography (OCT). METHODS: Using 3D reconstructions of OCT data, we analyzed minimal lumen area (MLA) and eccentricity of the jailed side-branch ostium in 41 patients who were treated with single stent crossover at coronary bifurcation lesions and subsequently underwent serial OCT follow-up. RESULTS: The MLA of jailed side-branch ostium calculated from quantitative coronary angiography (QCA) assuming a circular lumen markedly decreased after stent implantation (1.73±1.22mm(2) pre-intervention to 0.84±0.91mm(2) post-intervention, p<0.001). However, the MLA of jailed side-branch ostium measured at post-intervention by 3D-OCT (2.67±1.75mm(2)) was significantly larger than that measured by QCA (p<0.001). There were no statistically significant changes in MLA of jailed side-branch ostium based on 3D-OCT measurements during the follow-up (2.35±1.50mm(2) at 3-6 months post-intervention; 2.44±1.27mm(2) at 1-2 years post-intervention, p=0.098). The shapes of the jailed side-branch ostium were nearly elliptical (mean eccentricity index: 2.97±1.27 post-intervention; 2.79±1.17 at 3-6 months post-intervention; 2.59±1.02 at 1-2 years post-intervention). CONCLUSIONS: Compared to 3D-OCT measurements, QCA measurements overestimated the jailed side-branch ostial stenosis after single stent crossover due to eccentric morphology from orthogonal projection in coronary angiography. Significant changes in the MLA of jailed side-branch ostium by 3D-OCT were not observed during the follow-up.