Nonlocal Electrodynamic Modeling of Fluorescence Characteristics for Molecules in a Spherical Cavity

The emission characteristics for molecules in a spherical metallic microcavity are computed using a nonlocal electrodynamic model, based on a theory previously published by Fuchs and Claro [Phys. Rev. B 35, 3722 (1987)] for the multipole polarizability of a sphere. Both radially and tangentially oriented molecules at arbitrary locations inside the cavity are considered, and the results are compared with those from both the local response theory and those for molecules outside a spherical particle. The issue of reciprocity of the solutions for each of the sphere and cavity cases, respectively, is examined in the light of the nonlocal effects. It is observed that for emission frequencies below the surface plasmon frequency of the cavity material, the nonlocal effects in general lead to less surface-induced modifications of the molecular properties, similar to the situation for a spherical particle. However, the reciprocity nature between the solutions for the sphere and cavity disappears in the presence of nonlocal effects

Aryl Phosphoramidates of 5-Phospho Erythronohydroxamic Acid, A New Class of Potent Trypanocidal Compounds

RNAi and enzymatic studies have shown the importance of 6-phosphogluconate dehydrogenase (6-PGDH) in Trypanosoma brucei for the parasite survival and make it an attractive drug target for the development of new treatments against human African trypanosomiasis. 2,3-O-Isopropylidene-4-erythrono hydroxamate is a potent inhibitor of parasite Trypanosoma brucei 6-phosphogluconate dehydrogenase (6-PGDH), the third enzyme of the pentose phosphate pathway. However, this compound does not have trypanocidal activity due to its poor membrane permeability. Consequently, we have previously reported a prodrug approach to improve the antiparasitic activity of this inhibitor by converting the phosphate group into a less charged phosphate prodrug. The activity of prodrugs appeared to be dependent on their stability in phosphate buffer. Here we have successfully further extended the development of the aryl phosphoramidate prodrugs of 2,3-O-isopropylidene-4-erythrono hydroxamate by synthesizing a small library of phosphoramidates and evaluating their biological activity and stability in a variety of assays. Some of the compounds showed high trypanocidal activity and good correlation of activity with their stability in fresh mouse blood

Monte-Carlo Simulation of Pulsed Laser Deposition

Using the Monte Carlo method, we have studied the pulsed laser deposition process at the sub-monolayer regime. In our simulations, dissociation of an atom from a cluster is incorporated. Our results indicate that the pulsed laser deposition resembles molecular beam epitaxy at very low intensity, and that it is characteristically different from molecular beam epitaxy at higher intensity. We have also obtained the island size distributions. The scaling function for the island size distribution for pulsed laser deposition is different from that of molecular beam epitaxy.Comment: 15 pages, 8 figure

Theophylline–gentisic acid (1/1)

In the title 1:1 cocrystal, C7H8N4O2·C7H6O4, the anti-asthmatic drug theophylline (systematic name: 1,3-dimethyl-7H-purine-2,6-dione) and a non-steroidal anti-inflammatory drug, gentisic acid (systematic name: 2,5-dihydroxy­benzoic acid) crystallize together, forming two-dimensional hydrogen-bonded sheets involving N—H⋯O and O—H⋯N hydrogen bonds. The overall crystal packing features π–π stacking inter­actions [centroid–centroid distance = 3.348 (1) Å]. The cocrystal described herein belongs to the class of pharmaceutical cocrystals involving two active pharmaceutical ingredients which has been relatively unexplored to date

Grand challenges for aerosol science and technology

The Grand Challenges Workshop for Aerosol Science and Technology was organized for the International Aerosol Conference (IAC), in St Louis, September 2–7, 2018. The purpose of the workshop was to identify “Grand Challenges” for aerosol science and technology in the next decade and thereby indicate a viable research road map for the aerosol community

Revised Calibration Strategy for the CALIOP 532 nm Channel

The CALIPSO lidar (CALIOP) makes backscatter measurements at 532 nm and 1064 nm and linear depolarization ratios at 532 nm. Accurate calibration of the backscatter measurements is essential in the retrieval of optical properties. An assessment of the nighttime 532 nm parallel channel calibration showed that the calibration strategy used for the initial release (Release 1) of the CALIOP lidar level 1B data was acceptable. In general, the nighttime calibration coefficients are relatively constant over the darkest segment of the orbit, but then change rapidly over a short period as the satellite enters sunlight. The daytime 532 nm parallel channel calibration scheme implemented in Release 1 derived the daytime calibration coefficients from the previous nighttime coefficients. A subsequent review of the daytime 532 nm parallel channel calibration revealed that the daytime calibration coefficients do not remain constant, but vary considerably over the course of the orbit, due to thermally-induced misalignment of the transmitter and receiver. A correction to the daytime calibration scheme is applied in Release 2 of the data. Results of both nighttime and daytime calibration performance are presented in this paper

Explicit expressions for the minimum efficiency and most penetrating particle size of Nuclepore filters

Nuclepore filters are capillary pore membrane filters with an array of microscopic cylindrical holes of uniform diameters. Their structure is suitable for particle collection and ensuing offline analyses, therefore they are being widely used for exposure assessment of engineered nanoparticles, ambient PM2.5, virus, bacteria, asbestos, etc., as well as in powder manufacturing industries. However, there exists a particle size range in which all the filtration capture mechanisms are not effective. This size is the most penetrating particle size (MPPS), which corresponds to the minimum efficiency (ME) of the filter. Both MPPS and ME are important parameters for a user to select an adequate Nuclepore filter and preferred operating conditions. For rapid estimation of the MPPS and ME, we derived their explicit expressions by simplifying the formulas for the impaction, diffusion and interception deposition and differentiating the combined efficiency with respect to the particle size. The comparison between the experimental data and the prediction from the explicit expressions shows the explicit expressions can provide MPPS for a wide range of filter properties (pore radius, porosity and length) and filtration conditions (particle density, face velocity and temperature). The ME can also be estimated satisfactorily when a simplified term of filter surface diffusion deposition is further considered. By the explicit expressions of MPPS and ME, a quick screening for selecting a Nuclepore filter with the proper properties and suitable filtration conditions can be easily achieved. From the theoretical point of view, the explicit expressions facilitate better understanding of the effects of filter properties and conditions on the filtration characteristic

Network community cluster-based analysis for the identification of potential leukemia drug targets

Leukemia is a hematologic cancer which develops in blood tissue and causes rapid generation of immature and abnormal-shaped white blood cells. It is one of the most prominent causes of death in both men and women for which there is currently not an effective treatment. For this reason, several therapeutical strategies to determine potentially relevant genetic factors are currently under development, as targeted therapies promise to be both more effective and less toxic than current chemotherapy. In this paper, we present a network community cluster-based analysis for the identification of potential gene drug targets for acute lymphoblastic leukemia and acute myeloid leukemia.Peer ReviewedPostprint (author's final draft