19 research outputs found
Nutrition and cancer: A review of the evidence for an anti-cancer diet
It has been estimated that 30–40 percent of all cancers can be prevented by lifestyle and dietary measures alone. Obesity, nutrient sparse foods such as concentrated sugars and refined flour products that contribute to impaired glucose metabolism (which leads to diabetes), low fiber intake, consumption of red meat, and imbalance of omega 3 and omega 6 fats all contribute to excess cancer risk. Intake of flax seed, especially its lignan fraction, and abundant portions of fruits and vegetables will lower cancer risk. Allium and cruciferous vegetables are especially beneficial, with broccoli sprouts being the densest source of sulforophane. Protective elements in a cancer prevention diet include selenium, folic acid, vitamin B-12, vitamin D, chlorophyll, and antioxidants such as the carotenoids (α-carotene, β-carotene, lycopene, lutein, cryptoxanthin). Ascorbic acid has limited benefits orally, but could be very beneficial intravenously. Supplementary use of oral digestive enzymes and probiotics also has merit as anticancer dietary measures. When a diet is compiled according to the guidelines here it is likely that there would be at least a 60–70 percent decrease in breast, colorectal, and prostate cancers, and even a 40–50 percent decrease in lung cancer, along with similar reductions in cancers at other sites. Such a diet would be conducive to preventing cancer and would favor recovery from cancer as well
Spontaneous doping of the basal plane of MoS2 single layers through oxygen substitution under ambient conditions
The chemical inertness of the defect-free basal plane confers environmental
stability to MoS2 single-layers, but it also limits their chemical versatility
and catalytic activity. The stability of the pristine MoS2 basal plane against
oxidation under ambient conditions is a widely accepted assumption in the
interpretation of various studies and applications. However, single-atom level
structural investigations reported here reveal that oxygen atoms spontaneously
incorporate into the basal plane of MoS2 single layers during ambient exposure.
Our scanning tunneling microscopy investigations reveal a slow oxygen
substitution reaction, upon which individual sulfur atoms are one by one
replaced by oxygen, giving rise to solid solution type 2D MoS2-xOx crystals. O
substitution sites present all over the basal plane act as single-atomic active
reaction centers, substantially increasing the catalytic activity of the entire
MoS2 basal plane for the electrochemical H2 evolution reaction.Comment: 6 pages, 5 figure
Orienting MoS2 flakes into ordered films
Layered transition metal di-chalcogenide (TMD) materials exhibit a unique combination of structural anisotropy combined with rich chemistry that confers controllability over physical properties such as bandgap and magnetism. Most research in this area is focused on single layers that are technologically challenging to produce, especially when trying to dope and alloy the host lattice. In this work, we use MoS2 flakes as a model system for the production of deliberately oriented films for practical applications in which anisotropic materials are required. The proposed production method combines ball milling with exfoliation in solution of MoS2 flakes, followed by their arrangement on a large centimeter-scale substrate by a simple and non-expensive procedure. The results show that the level of orientation achieved using the proposed system is as good as that of materials that were pressed and subjected to thermal treatment. The ball milling and exfoliation processes maintain the original crystalline structure of the MoS2 flakes, and the XRD results show that additional crystallographic phases were not produced. Lattice parameters are preserved, which verifies that other species such as water molecules did not intercalate into the MoS2 molecules. The proposed method of producing oriented films is universal, and as such, it is useful both for pure materials and for mixtures of compounds, the latter of which can be used to produce films with specifically tailored physical properties