Two Are Better than One: Halloysite Nanotubes-Supported Surface Imprinted Nanoparticles Using Synergy of Metal Chelating and Low pKa Boronic Acid Monomers for Highly Specific Luteolin Binding under Neutral Condition

2017 ◽  
Vol 9 (38) ◽  
pp. 33191-33202 ◽  
Author(s):  
Shucheng Liu ◽  
Jinxin Liu ◽  
Jianming Pan ◽  
Jialu Luo ◽  
Xiangheng Niu ◽  
...  
Keyword(s):  
Boronic Acid ◽  
Halloysite Nanotubes ◽  
Neutral Condition ◽  
Metal Chelating ◽  
Better Than

The Impact of Positive Mood on Learning

1996 ◽  
Vol 19 (3) ◽  
pp. 153-162 ◽  
Author(s):  
Tanis Bryan ◽  
Sarup Mathur ◽  
Karen Sullivan
Keyword(s):  
Learning Disabilities ◽  
Mood Induction ◽  
Positive Mood ◽  
Learning Task ◽  
Neutral Condition ◽  
Students With Learning Disabilities ◽  
Neutral Mood ◽  
The Impact ◽  
Mood Condition ◽  
Better Than

The primary intent of this study was to examine the effects of a brief positive mood induction on a learning task that stimulates beginning reading acquisition. A secondary intent was to examine the durability of this effect across a period of two weeks. Sixty students, half average-achieving and half with learning disabilities, were randomly assigned to either a positive or a neutral mood induction condition. In an effort to control for the effects of prior knowledge, all students received instruction in elementary Hindi language on a series of five tasks. After two weeks, the instruction and tasks were readministered. The results of a MANCOVA indicated that both groups of students in the positive mood condition performed better than those in the neutral condition, although not statistically so. However, gain scores indicated that across a two-week period, students with learning disabilities in the positive condition performed significantly better than students with learning disabilities in the neutral condition.

scholarly journals Development of fluorescent sensors for the detection of hydrophobic amines and glycolipids

2017 ◽  
Author(s):  
◽  
Charles W. Jr. Littlefield
Keyword(s):  
Boronic Acid ◽  
Electrostatic Interactions ◽  
Fluorescent Sensor ◽  
Acid Group ◽  
Fluorescent Sensors ◽  
Synthetic Methods ◽  
Amide Bond ◽  
Primary Amines ◽  
New Synthesis ◽  
Better Than

A novel fluorescent sensor was designed and synthesized to detect hydrophobic amines and was used to extract them from synthetically prepared vesicles. This sensor had a higher affinity for diamines than primary amines, providing a fluorescence decrease upon binding both analytes. This sensor bound longer chain amines such as decylamine and 1,10-diaminodecane, better than shorter chain amines such as octylamine. This binding is influenced by both hydrophobic effects and electrostatic interactions between the sensor and analyte, driven by the hydrophobic cavity on the sensor. The sensor also unexpectedly binds to spermine and spermidine, however, with an increase in fluorescence. The mechanism for this phenomenon is not yet understood. The sensor showed it is possible to remove hydrophobic amines from synthetic veiscles, which can be applied to biological systems. A fluorescent sensor for glycolipids was also attempted to be synthesized by several different methods, incurring a new synthesis through redesigning the synthesis. Each method provided undesired products, decomposition, or no reactivity. Initial redesigns were due to complications in solubility of the carbazole aldehyde. Elongating the ester chain enhanced the solubility, but it remained unreactive towards any of the attempted reactions. This redesigned the sensor with a protected acid group that has been tested towards amide bond formation reactions to install the boronic acid or a haloarene, which will then undergo a Miyaura Borylation to install the boronic acid. If this does not prove successful, it will require alternative synthetic methods to install the boronic acid.

scholarly journals Antioxidant Properties, Sensory Evaluation and Mineral Content of Cardaba Banana and Plantain Flours

2019 ◽  
Vol 4 (1) ◽  
pp. 52-64
Author(s):  
Babalola R. Taiwo ◽  
Taiwo A. Kehinde
Keyword(s):  
Sensory Evaluation ◽  
Mineral Content ◽  
Antioxidant Properties ◽  
Drying Method ◽  
Overall Acceptability ◽  
Metal Chelating ◽  
Banana Flour ◽  
Better Than

AbstractUnripe cardaba banana and plantain slices were processed into flour. The effects of treatment (blanching/unblanched) and drying method (sun, 50ºC and 70ºC) were recorded. The antioxidant properties of the flour samples, sensory evaluation and minerals content were all determined. DPPH, TPC, FRAP and Metal chelating abilities were higher in cardaba flour (89.77 to 99.18%, 15.00 to 46.00 μgGAE/100g, 0.28 to 0.69 AAEμg/g and 38.90 to 96.53%) than in plantain (91.32 to 98.17%, 10.00 to 34.00 μgGAE/100g, 0.28 to 0.52 AAEμg/g and 33.71 to 94.98%) samples. Calcium, zinc and phosphorus were lower in cardaba banana flour compared to plantain flour. In overall acceptability, amala (a traditional South-western Nigerian meal) from blanched and unblanched cardaba banana flour was preferred to amala from blanched and unblanched plantain flour. Amala from oven-dried samples was considered better than sun-dried samples.

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Localization of immunolabels by electron microscopy and image averaging

1983 ◽  
Vol 41 ◽  
pp. 282-283
Author(s):  
J. Frank ◽  
P.-Y. Sizaret ◽  
A. Verschoor ◽  
J. Lamy
Keyword(s):  
Electron Microscopy ◽  
Single Particle ◽  
Attachment Site ◽  
Uranyl Acetate ◽  
Limulus Polyphemus ◽  
Resolution Limit ◽  
Electron Microscopic ◽  
Image Averaging ◽  
Top View ◽  
Better Than

The accuracy with which the attachment site of immunolabels bound to macromolecules may be localized in electron microscopic images can be considerably improved by using single particle averaging. The example studied in this work showed that the accuracy may be better than the resolution limit imposed by negative staining (∽2nm).The structure used for this demonstration was a halfmolecule of Limulus polyphemus (LP) hemocyanin, consisting of 24 subunits grouped into four hexamers. The top view of this structure was previously studied by image averaging and correspondence analysis. It was found to vary according to the flip or flop position of the molecule, and to the stain imbalance between diagonally opposed hexamers (“rocking effect”). These findings have recently been incorporated into a model of the full 8 × 6 molecule.LP hemocyanin contains eight different polypeptides, and antibodies specific for one, LP II, were used. Uranyl acetate was used as stain. A total of 58 molecule images (29 unlabelled, 29 labelled with antl-LPII Fab) showing the top view were digitized in the microdensitometer with a sampling distance of 50μ corresponding to 6.25nm.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Electron Microscopic Observation of the Longitudinal Organization of Poly (p-Phenylene Terephthalamide) Fibers

1982 ◽  
Vol 40 ◽  
pp. 680-681
Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Microscopic Observation ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Aromatic Polyamides ◽  
Radial Arrangement ◽  
Scanning Electron ◽  
Better Than

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.

A High Angle, Double Tilting Cold Stage for the AEI EM7

1974 ◽  
Vol 32 ◽  
pp. 450-451
Author(s):  
P.R. Swann ◽  
A.E. Lloyd
Keyword(s):  
Habit Plane ◽  
Temperature Control ◽  
Tilt Angle ◽  
Cooling System ◽  
Thermal Drift ◽  
High Angle ◽  
Cold Stage ◽  
High Degree ◽  
Better Than

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.

Thermal Considerations in Lens Regulator Systems

1970 ◽  
Vol 28 ◽  
pp. 358-359
Author(s):  
K.C. Newton
Keyword(s):  
Electron Microscope ◽  
Thermal Effects ◽  
Environmental Control ◽  
Reference Networks ◽  
Better Than

Thermal effects in lens regulator systems have become a major problem with the extension of electron microscope resolution capabilities below 5 Angstrom units. Larger columns with immersion lenses and increased accelerating potentials have made solutions more difficult by increasing the power being handled. Environmental control, component choice, and wiring design provide answers, however. Figure 1 indicates with broken lines where thermal problems develop in regulator systemsExtensive environmental control is required in the sampling and reference networks. In each case, stability better than I ppm/min. is required. Components with thermal coefficients satisfactory for these applications without environmental control are either not available or priced prohibitively.

Finding the Right Problems: Some HREM Applications to Interfaces

1984 ◽  
Vol 42 ◽  
pp. 376-379
Author(s):  
D. Cherns
Keyword(s):  
Grain Boundaries ◽  
High Resolution Electron Microscopy ◽  
Boundary Structure ◽  
Atomic Structures ◽  
Grain Boundary Structure ◽  
Resolution Electron ◽  
Point To Point ◽  
The Right ◽  
New Generation ◽  
Better Than

The use of high resolution electron microscopy (HREM) to determine the atomic structure of grain boundaries and interfaces is a topic of great current interest. Grain boundary structure has been considered for many years as central to an understanding of the mechanical and transport properties of materials. Some more recent attention has focussed on the atomic structures of metalsemiconductor interfaces which are believed to control electrical properties of contacts. The atomic structures of interfaces in semiconductor or metal multilayers is an area of growing interest for understanding the unusual electrical or mechanical properties which these new materials possess. However, although the point-to-point resolutions of currently available HREMs, ∼2-3Å, appear sufficient to solve many of these problems, few atomic models of grain boundaries and interfaces have been derived. Moreover, with a new generation of 300-400kV instruments promising resolutions in the 1.6-2.0 Å range, and resolutions better than 1.5Å expected from specialist instruments, it is an appropriate time to consider the usefulness of HREM for interface studies.

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