RESUMEN
Silicon (Si) has a large theoretical capacity of 4200 mAhg-1 and has great potential as a high-performance anode material for Li ion batteries (LIBs). Meanwhile, nanostructures can exploit the potential of Si and, accordingly, many zero-dimensional (0D) and one-dimensional (1D) Si nanostructures have been studied. Herein, we report on two-dimensional (2D) Si nanostructures, Si nanosheets (SiNSs), as anodes for LIBs. These 2D Si nanostructures, with a thickness as low 5 nm and widths of several micrometers, show reversible crystalline-amorphous phase transformations with the lithi-/delithiation by the dimensionality of morphology and large surface area. The reversible crystalline-amorphous phase transformation provides a structural stability of Li+ insertions and makes SiNSs promising candidates for reliable high-performance LIBs anode materials.
RESUMEN
We have conducted extensive theoretical and experimental investigations to unravel the origin of the electrochemical properties of hybrid Mg(2+)/Li(+) rechargeable batteries at the atomistic and macroscopic levels. By revealing the thermodynamics of Mg(2+) and Li(+) co-insertion into the Mo6S8 cathode host using density functional theory calculations, we show that there is a threshold Li(+) activity for the pristine Mo6S8 cathode to prefer lithiation instead of magnesiation. By precisely controlling the insertion chemistry using a dual-salt electrolyte, we have enabled ultrafast discharge of our battery by achieving 93.6% capacity retention at 20 C and 87.5% at 30 C, respectively, at room temperature.
RESUMEN
Galvanic couple-assisted dissolution of Mg metal in an ethereal solution containing tris(2H-hexafluoroisopropyl)borate was utilized to prepare an efficient Al-compatible electrolyte for rechargeable Mg batteries. The electrolyte exhibited conditioning-free Mg deposition, high oxidative stability (3.5 V vs. Mg/Mg2+), and a superb electrochemical performance with various cathodes on an Al current collector.
RESUMEN
Young radish (Raphanus sativus L), a member of the mustard family (Cruciferae), is a common ingredient of Kimchi. Although few reports have described anaphylaxis to cruciferous vegetables, we report the case of anaphylaxis induced by contact with young radish. A 46-year-old female with a history of contact allergy to metal presented to our emergency room (ER) with dizziness, generalized eruption and gastrointestinal upset. Her symptoms developed after re-exposure to young radish while chopping it. Hypotensive blood pressures were noted. Three days prior, the patient had experienced generalized urticaria with pruritus immediately after chopping the fresh young radish, which resolved spontaneously. In the ER, her symptoms improved by the administration of epinephrine (0.3 mL), antihistamine (chlorpheniramine) and isotonic saline hydration. A skin prick test with young radish extract showed positive reactivity. The same skin test was negative in five adult controls. IgE-mediated hypersensitivity could be an important immunologic mechanism in the development of young radish-induced anaphylaxis.
RESUMEN
BACKGROUND/AIMS: The relationship between Crohn's disease and gallstones is established. However, the prevalence and risk factors for gallstones in patients with ulcerative colitis (UC) are not yet well understood. The aim of this study was to evaluate the prevalence and risk factors of gallstones in patients with UC. METHODS: This study was a retrospective single center study. A total of 87 patients with UC and 261 healthy controls were enrolled. Age, sex, and body mass index were matched. To investigate risk factors, the extent of UC, duration of disease, number of hospital admissions, and number of steroid treatments in patients with UC were evaluated. RESULTS: The prevalence of gallstones in patients with UC was 13.8%, whereas that in healthy controls was only 3.1% (P<0.001). For patients with UC, patients ≥50 years of age had a 3.6-times higher risk of gallstones compared to that in those <50 years of age, and the difference was statistically significant (odds ratio, 3.60; confidence interval, 1.03-12.61) in univariate analysis. There were no statistically significant disease-related risk factors for gallstones in UC patients. CONCLUSIONS: This is the first study of gallstone prevalence in Korean UC patients. In this study, patients with UC had a higher prevalence of gallstones compared to that in well-matched healthy controls. Age seemed to be a possible risk factor, and more studies are needed. Further prospective, large-scale studies will be required to confirm the risk factors for gallstones in UC patients.