Carbohydrate Analogue Microarrays for Identification of Lectin‐Selective Ligands

Fifty‐five mono‐ and disaccharide analogues were prepared and used for the construction of microarrays to uncover lectin‐selective ligands. The microarray study showed that two disaccharide analogues, 28′ and 44′ , selectively bind to Solanum tuberosum lectin (STL) and wheat germ agglutinin (WGA), respectively. Cell studies indicated that 28′ and 44′ selectively block the binding of STL and WGA to mammalian cells, unlike the natural ligand LacNAc, which suppresses binding of both STL and WGA to cells.     

Modeling of tensile strength in polymer particulate nanocomposites based on material and interphase properties

In this work, a simple model is presented to determine tensile/yield strength in polymer nanocomposites containing spherical nanofillers based on material and interphase properties. The accuracy of the proposed model is estimated by comparing with the experimental strength of several samples from the literature. In addition, the effects of thickness (t) and tensile strength (σ_i) of the interphase as well as the radius (R) and volume fraction ( ) of the nanoparticles on the tensile strength are explained according to the proposed model. The high level of nanoparticle strength (more than 100 GPa) commonly leads to overestimates of the tensile strength of nanocomposites, whereas the assumption of correct interphase properties produces accurate calculations. The tensile strength of nanocomposites does not change at σ_i < 38 MPa, while it increases by 140% at t = 20 nm and σ_i = 90 MPa. However, a maximum 14% growth in tensile strength is obtained with the optimum values of = 0.04 and R = 10 nm. Therefore, the concentration and size of the nanoparticles have minor effects on the tensile strength of nanocomposites, but the major influences of interphase thickness and strength are pronounced. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44869.     

Rapid and efficient deoxygenation of sulfoxides to sulfides with tantalum(V) chloride/sodium iodide system

TaCl₅/NaI system converts a wide range of sulfoxides to the corresponding sulfides in high yields with short reaction times, under mild conditions. It is worth mentioning that this protocol is chemoselective and tolerates various functional groups (such as –Br, –Cl, –OCH₃, –CHO, and –NO₂) and double bond.     

Thermal noise in aqueous quadrupole micro- and nano-traps

ABSTRACT: Recent simulations and experiments with aqueous quadrupole micro-traps have confirmed a possibility for control and localization of motion of a charged particle in a water environment, also predicting a possibility of further reduction of the trap size to tens of nano-meters for trapping charged bio-molecules and DNA segments. We study the random thermal noise due to Brownian motion in water which significantly influences the trapping of particles in an aqueous environment. We derive the exact, closed-form expressions for the thermal fluctuations of position and velocity of a trapped particle and thoroughly examine the properties of the rms for the fluctuations as functions of the system parameters and time. The instantaneous signal transferring mechanism between the velocity and position fluctuations could not be achieved in the previous phase-average approaches.     

Photoluminescence enhancement of quantum dots on Ag nanoneedles

ABSTRACT: Noble-metal nanostructure allows us to tune optical and electrical properties, which has high utility for real-world application. We studied surface plasmon induced emission of semiconductor quantum dots (QDs) on engineered metallic nanostructures. Highly passive organic ZnS capped CdSe QDs were spin coated on poly-(methyl methacrylate) (PMMA) covered Ag films which brought QDs near to metallic surface. We obtained the enhanced electromagnetic field and reduced fluorescence lifetimes from CdSe/ZnS quantum dots (QDs) due to the strong coupling of emitters wave function with the Ag plasmon resonance. Observed changes include a six-fold increase in the fluorescence intensity and striking reduction in fluorescence lifetimes of CdSe/ZnS QDs on rough Ag nanoneedle compared to the case of smooth surfaces. The advantages of using those nanocomposites are expected for high efficiency light-emitting diodes, platform fabrication of biological and environmental monitoring, and high contrast imaging.     

Prognosis of breast cancer is associated with one-carbon metabolism related nutrients among Korean women

ABSTRACT: BACKGROUND: The 5-year survival rate for breast cancer among Korean women has increased steadily; however, breast cancer remains the leading cause of cancer mortality among women. One-carbon metabolism, which requires an adequate supply of methyl group donors and B vitamins, may affect the prognosis of breast cancer. This aim of this study was to investigate the associations of dietary intake of vitamin B2, vitamin B6 and folate before diagnosis on the prognosis of breast cancer. METHODS: We assessed the dietary intake using a food frequency questionnaire with 980 women who were newly diagnosed and histopathologically confirmed to have primary breast cancer from hospitals in Korea, and 141 disease progression events occurred. Cox's proportional hazard regression models were used to estimate the hazard ratio (HR) and 95% confidence interval (95% CI) adjusting for age, education, recruitment sites, TNM stage, hormone status, nuclear grade and total calorie. RESULTS: There was no significant association between any one-carbon metabolism related nutrients (vitamin B2, B6 and folate) and the progression of breast cancer overall. However, one-carbon metabolism related nutrients were associated with disease progression in breast cancer patients stratified by subtypes. In ER + and/or PR + breast cancers, no association was observed; however, in ER--/PR-- breast cancers, a high intake of vitamin B2 and folate statistically elevated the HR of breast cancer progression (HR = 2.28; 95% CI, 1.20-4.35, HR = 1.84; 95% CI, 1.02-3.32, respectively) compared to a low intake. This positive association between the ER/PR status and progression of the disease was profound when the nutrient intakes were categorized in a combined score (Pinteraction = 0.018). In ER--/PR-- breast cancers, high combined scores were associated with a significantly poor DFS compared to those belonging to the low score group (HR = 3.84; 95% CI, 1.70-8.71). CONCLUSIONS: In conclusion, our results suggest that one-carbon related nutrients have a role in the prognosis of breast cancer depending on the ER/PR status.     

Virus-templated iridium oxide-gold hybrid nanowires for electrochromic application

A highly porous electrode comprised of biologically templated iridium oxide-gold (IrO(2)-Au) hybrid nanowires is introduced for electrochromic applications. A filamentous M13 virus is genetically engineered to display IrO(2)-binding peptides on the viral surface and used as a template for the self-assembly of IrO(2) nanoclusters into a nanowire. The open porous morphology of the prepared nanowire film facilitates ion transport. Subsequently, the redox kinetics of the IrO(2) nanowires seems to be limited by the electric resistance of the nanowire film. To increase the electron mobility in the nanowires, gold nanoparticles are chemically linked to the virus prior to the IrO(2) mineralization, forming a gold nanostring structure along the long axis of the virus. The resulting IrO(2)-Au hybrid nanowires exhibit a switching time of 35 ms for coloration and 25 ms for bleaching with a transmission change of about 30.5% at 425 nm. These values represent almost an order of magnitude faster switching responses than those of an IrO(2) nanowire film having the similar optical contrast. This work shows that genetically engineered viruses can serve as versatile templates to co-assemble multiple functional molecules, enabling control of the electrochemical properties of nanomaterials.     

High performance of a solid-state flexible asymmetric supercapacitor based on graphene films

Solid-state flexible energy storage devices hold the key to realizing portable and flexible electronic devices. Achieving fully flexible energy storage devices requires that all of the essential components (i.e., electrodes, separator, and electrolyte) with specific electrochemical and interfacial properties are integrated into a single solid-state and mechanically flexible unit. In this study, we describe the fabrication of solid-state flexible asymmetric supercapacitors based on an ionic liquid functionalized-chemically modified graphene (IL-CMG) film (as the negative electrode) and a hydrous RuO(2)-IL-CMG composite film (as the positive electrode), separated with polyvinyl alcohol-H(2)SO(4) electrolyte. The highly ordered macroscopic layer structures of these films arising through direct flow self-assembly make them simultaneously excellent electrical conductors and mechanical supports, allowing them to serve as flexible electrodes and current collectors in supercapacitor devices. Our asymmetric supercapacitors have been optimized with a maximum cell voltage up to 1.8 V and deliver a high energy density (19.7 W h kg(-1)) and power density (6.8 kW g(-1)), higher than those of symmetric supercapacitors based on IL-CMG films. They can operate even under an extremely high rate of 10 A g(-1) with 79.4% retention of specific capacitance. Their superior flexibility and cycling stability are evident in their good performance stability over 2000 cycles under harsh mechanical conditions including twisted and bent states. These solid-state flexible asymmetric supercapacitors with their simple cell configuration could offer new design and fabrication opportunities for flexible energy storage devices that can combine high energy and power densities, high rate capability, and long-term cycling stability.     

Opuntia humifusa Supplementation Increased Bone Density by Regulating Parathyroid Hormone and Osteocalcin in Male Growing Rats

We investigated the effect of Opuntia humifusa (O. humifusa) supplementation on bone density and related hormone secretion in growing male rats. Sixteen six-week-old male Sprague-Dawley rats were randomly divided into two groups; control diet group (CG, n = 8), and experimental diet group (EG, n = 8). The rats in the CG were given a control diet and those in the EG were given 5% O. humifusa added to the control diet for eight weeks. The serum OC level of the EG was significantly higher than that of the CG, and the serum parathyroid hormone (PTH) level of EG was significantly lower than that of the CG. In addition, the femoral and tibial BMD of the EG were significantly higher values than those of the CG, and the tibial BMC of the EG was significantly higher than that of the CG. These results suggest that O. humifusa supplementation has a positive effect on bone density by suppressing PTH and increasing the OC level in growing male rats.