The Minimal Occupancy Level of the Clathrate Hydrate Host Lattice and the Intercalation Heat of the Guest Molecules in the Chlorine Hydrates

The minimal occupancy level (θ_min) of the clathrate lattice of gas molecules is defined as the number of guest molecules in the host clathrate lattice, which can stabilize the thermodynamically unstable empty cage by covering the energy demand of the transformation of hexagonal ice into empty clathrate lattice (ΔH_trans). The θ_min values for chlorine hydrate were determined from the n = f(p)_T=const. relationship and the average molar intercalation heat of chlorine in the type I clathrate lattice was also calculated for both type of cavities.     

Dietary agents in cancer prevention: an immunological perspective(†)

Skin cancer is the most common form of cancer diagnosed in the United States. Exposure to solar ultraviolet (UV) radiations is believed to be the primary cause for skin cancer. Excessive UV radiation can lead to genetic mutations and damage in the skin's cellular DNA that in turn can lead to skin cancer. Lately, chemoprevention by administering naturally occurring non-toxic dietary compounds has proven to be a potential strategy to prevent the occurrence of tumors. Attention has been drawn toward several natural dietary agents such as resveratrol, one of the major components found in grapes, red wines, berries and peanuts, proanthocyanidins from grape seeds, (-)-epigallocatechin-3-gallate from green tea, etc. However, the effect these dietary agents have on the immune system and the immunological mechanisms involved therein are still being explored. In this review, we shall focus on the role of key chemopreventive agents on various immune cells and discuss their potential as antitumor agents with an immunological perspective.     

Agrobacterium-Mediated Gene Transfer in Plants and Biosafety Considerations

Agrobacterium, the natures?? genetic engineer, has been used as a vector to create transgenic plants. Agrobacterium-mediated gene transfer in plants is a highly efficient transformation process which is governed by various factors including genotype of the host plant, explant, vector, plasmid, bacterial strain, composition of culture medium, tissue damage, and temperature of co-cultivation. Agrobacterium has been successfully used to transform various economically and horticulturally important monocot and dicot species by standard tissue culture and in planta transformation techniques like floral or seedling infilteration, apical meristem transformation, and the pistil drip methods. Monocots have been comparatively difficult to transform by Agrobacterium. However, successful transformations have been reported in the last few years based on the adjustment of the parameters that govern the responses of monocots to Agrobacterium. A novel Agrobacterium transferred DNA-derived nanocomplex method has been developed which will be highly valuable for plant biology and biotechnology. Agrobacterium-mediated genetic transformation is known to be the preferred method of creating transgenic plants from a commercial and biosafety perspective. Agrobacterium-mediated gene transfer predominantly results in the integration of foreign genes at a single locus in the host plant, without associated vector backbone and is also known to produce marker free plants, which are the prerequisites for commercialization of transgenic crops. Research in Agrobacterium-mediated transformation can provide new and novel insights into the understanding of the regulatory process controlling molecular, cellular, biochemical, physiological, and developmental processes occurring during Agrobacterium-mediated transformation and also into a wide range of aspects on biological safety of transgenic crops to improve crop production to meet the demands of ever-growing world??s population.     

Graphical approach for complex PSA cycle scheduling

A simple graphical approach for complex pressure swing adsorption (PSA) cycle scheduling has been developed. This new methodology involves a priori specifying the cycle steps, their sequence, and the number of beds, and then following a systematic procedure that requires filling in a 2-D grid based on a few simple rules, some heuristics and some experience. The outcome or solution is a grid comprised of columns that represent the total cycle time, rows that represent the total number of beds, and cells that represent the duration of each cycle step, i.e., the complete cycle schedule. This new approach has been tested successfully against several cycle schedules taken from the literature, including a two-bed four-step Skarstrom cycle, a four-bed nine-step process with two equalization steps, a nine-bed eleven-step process with three pressure equalization steps, and a six-bed thirteen-step process with four pressure equalization steps and four idle steps. This approach also revealed the existence of numerous cycle schedules for each bed and cycle step combination examined. Although it cannot identify the total number of permutations or which one is better, it does provide a very straightforward way to determine some of the possible cycle schedules of virtually any PSA process that can be conceived.     

A catalyst free convenient one-pot synthesis of multisubstituted chromeno-thiazolones

Herein, we report a simple, convenient and catalyst free one-pot synthesis of chromenothiazolone analogues via multicomponent reaction between thiazolidine-2,4-dione, aromatic aldehyde and phenol. This reaction proceeded smoothly in good to excellent yields and offered several other advantages including short reaction time, simple experimental workup procedure and no byproduct.     

Large-scale shell-model calculations for even-odd <Superscript>61−65</Superscript>Fe isotopes

Large-scale shell-model calculations have been performed to calculate the negative-parity states of even-odd ⁶¹⁻⁶⁵Fe isotopes. The results are compared with the recent experimental data reported at Legnaro National Laboratories and also with earlier calculations with fpg interaction in a truncated configuration space. It is observed that negative parity states of ⁶¹Fe can be well reproduced with GXPF1A interaction in full fp space without truncation. For ⁶³Fe the correct ordering of levels is not reproduced. The structure of the wave function for the ground state and first excited state suggests that the ordering of the single-particle energy levels gets modified due to monopole correction.     

Large-scale shell model calculations for odd-odd <Superscript>58-62</Superscript>Mn isotopes

Large-scale shell model calculations have been carried out for odd-odd ^58-62Mn isotopes in two different model spaces. The first set of calculations has been carried out in full fp shell valence space with two recently derived fp shell interactions namely GXPF1A and KB3G treating ⁴⁰Ca as core. The second set of calculations has been performed in the fpg _9/2 valence space with the fpg interaction treating ⁴⁸Ca as core and imposing a truncation by allowing up to a total of six particle excitations from the 0f _7/2 orbital to the upper fp orbitals for protons and from the upper fp orbitals to the 0g _9/2 orbital for neutrons. For low-lying states in ⁵⁸Mn , KB3G and GXPF1A both predict good results and for ⁶⁰Mn , KB3G is much better than GXPF1A. For negative-parity and high-spin positive-parity states in both isotopes the fpg interaction is required. Experimental data on ⁶²Mn is sparse and therefore it is not possible to make any definite conclusions. More experimental data on negative-parity states is needed to ascertain the importance of 0g _9/2 and higher orbitals in neutron-rich Mn isotopes.     

Construction of spatial-coherence spectral filters using a Fourier-achromat system

Theoretical investigations made not long ago regarding the construction of spatial-coherence spectral filters (SCSFs) are rendered into experiments by designing and fabricating a Fourier-achromat experimental setup analyzed in the theoretical studies. It is shown that the phenomenon of spectral shift due to spatial coherence also known as the Wolf effect can be exploited to make special types of low-pass and band-pass spectral filters with special spectral characteristics that are not shown by the conventional filters. A Fourier-achromat is employed to construct the SCSFs. The experimental results within the experimental limitations and measurement uncertainty agree well with the theory. These filters might find applications in (i) astronomy (in the search of particular spectral lines) (ii) developing spectrum-selective optical interconnects or (iii) in cryptography.     

Experimental Results on Using General Disjunctions in Branch-and-Bound for General-Integer Linear Programs

Typical implementations of branch-and-bound for integer linear programs choose to branch on single variables. In this paper we explore the use of general disjunctions for branching when solving linear programs with general-integer variables. We give computational results that show that the size of the enumeration tree can be greatly reduced by branching on such disjunctions rather than on single variables.