An evaluation of exogenous application of protoporphyrin IX and its dimethyl ester as a photodynamic diagnostic agent in poorly differentiated human nasopharyngeal carcinoma

5-Aminolevulinic acid and its esterified analogues have been under much investigation to enhance the endogenous production of protoporphyrin IX (PpIX) in tumor cells. However, in this work, we studied the in vitro and in vivo efficacy of exogenously administered PpIX and its esterified analogue, PpIX dimethyl ester (PME), in poorly differentiated human nasopharyngeal carcinoma (NPC/CNE-2) as a photodynamic diagnostic (PDD) agent. NPC/CNE-2 at its earliest time, 1 h after incubation with PME in in vitro studies, has exhibited 64% (P <0.01) higher tumor to normal cell (T/N) fluorescence ratio than with PpIX. In an in vivo mouse xenograft model, comparable photosensitizer concentration in tumor after intravenous administration was observed at 1-3 h time points, but at 9 h, PME had 31% (P=0.05) greater concentration in tumor compared with PpIX. In addition, by constituting PME and PpIX in different topical gel composites, of which, PME gel composition of 8:2 Plasdone and Gantrez resulted in the highest T/N ratio at 6 h after application (34%; P <0.05) in comparison with other gel composites. Evaluation of PME and PpIX constituted in the delivery vehicles investigated showed comparable selectivity for tumor at 1-3 h, thus neither photosensitizer is more efficient than the other for PDD at the early time points; however, beyond 6 h, PME had higher selectivity for tumor compared with PpIX. Thus, further investigation is warranted to improve the drug delivery vehicle for greater tumor selectivity at a shorter incubation time.     

New metalloligands [M(SC[O]Ph)(4)](-): synthesis and characterization of polymeric [A(MeCN)(x)[M(SC[O]Ph)(4)]] compounds (A = Li,Na and K; M = Ga and In; x = 0-2)

Exploiting the ability of the [M(SC[O]Ph)(4)](-) anion to behave like an anionic metalloligand, we have synthesized [Li[Ga(SC[O]Ph)(4)]] (1), [Li[In(SC[O]Ph)(4)]] (2), [Na[Ga(SC[O]Ph)(4)]] (3), [Na(MeCN)[In(SC[O]Ph)(4)]] (4), [K[Ga(SC[O]Ph)(4)]] (5), and [K(MeCN)(2)[In(SC[O]Ph)(4)]] (6) by reacting MX(3) and PhC[O]S(-)A(+) (M = Ga(III) and In(III); X = Cl(-) and NO(3)(-); and A = Li(I), Na(I), and K(I)) in the molar ratio 1:4. The structures of 2, 4, and 6 determined by X-ray crystallography indicate that they have a one-dimensional coordination polymeric structure, and structural variations may be attributed to the change in the alkali metal ion from Li(I) to Na(I) to K(I). Crystal data for 2 x 0.5MeCN x 0.25H(2)O: monoclinic space group C2/c, a = 24.5766(8) A, b = 13.2758(5) A, c = 19.9983(8) A, beta = 108.426(1) degrees, Z = 8, and V = 6190.4(4) A(3). Crystal data for 4: monoclinic space group P2(1)/c, a = 10.5774(7) A, b = 21.9723(15) A, c = 14.4196(10) A, beta = 110.121(1) degrees, Z = 4, and V = 3146.7(4) A(3). Crystal data for 6: monoclinic space group P2(1)/c, a = 12.307(3) A, b = 13.672(3) A, c = 20.575(4) A, beta = 92.356(4) degrees, Z = 4, and V = 3458.8(12) A(3). The thermal decomposition of these compounds indicated the formation of the corresponding AMS(2) materials.     

Effect of optical disorder and single defects on the expansion of a Bose-Einstein condensate in a one-dimensional waveguide

We investigate the one-dimensional expansion of a Bose-Einstein condensate in an optical guide in the presence of a random potential created with optical speckles. With the speckle the expansion of the condensate is strongly inhibited. A detailed investigation has been carried out varying the experimental conditions and checking the expansion when a single optical defect is present. The experimental results are in good agreement with numerical calculations based on the Gross-Pitaevskii equation.     

Bose-Einstein condensate in a random potential

An optical speckle potential is used to investigate the static and dynamic properties of a Bose-Einstein condensate in the presence of disorder. With small levels of disorder, stripes are observed in the expanded density profile and strong damping of dipole and quadrupole oscillations is seen. Uncorrelated frequency shifts of the two modes are measured and are explained using a sum-rules approach and by the numerical solution of the Gross-Pitaevskii equation.     

Interaction between salinity intrusion and vegetation succession: A modeling approach

Predicting potential changes in groundwater salinity in low-lying coastal regions due to climate change is important, where coastal vegetation is abundant, succession competition between halophytes and glycophytes plays a significant role in the salinity budget. Sea level rise enhances salinity intrusion, contributing an additional dimension to vegetation competition. A new simulation model known as mangrove-hardwood hammock model coupled with saturated-unsaturated transport (MANTRA) has recently been developed by the authors to simulate groundwater salinity regimes in the presence of vegetation competition, subject to climate change. MANTRA is based upon linking two existing Unites States geological survey (USGS) simulation models known as mangrove-hardwood hammock model (MANHAM) and saturated-unsaturated transport (SUTRA). MANHAM simulates the evolution of vegetation succession subject to changing groundwater salinity. SUTRA simulates saturated and unsaturated transport of solutes and salinity in groundwater given sea salinity. MANTRA improves the simulation robustness to simultaneously simulate groundwater hydrology, salinity and coastal vegetation succession subject to sea level rise. Some simulation results will be presented to demonstrate the impact of sea level rise on coastal vegetation succession and groundwater salinity.     

Evaporative Preconcentration of Fluorescent Protein Samples in Capillary Based Microplates

The preconcentration of analytes is important in biochemical analysis as it offers the ability to detect for trace species, and increase signal-to-noise ratios when using optical sensing on fluorophores. A strong advantage of the evaporation technique lies in its ability to operate without the need of any energy source; albeit major challenges exist on how to increase the surface area exposure to air for heightened evaporation, ensure no further increases once specified analyte concentrations have been achieved, and not needing any intervening membranes. We demonstrate here that the droplet creation and retraction approach in capillary based microplates offers such abilities whilst at the same time facilitating mixing.     

Large-scale synthesis of high-quality ultralong copper nanowires

The present difficulties in synthesis of one-dimensional copper are short length, nonlinear morphology, polydispersivity, poor crystallinity, low yield, and process complexity. In this work, we demonstrate that high-quality ultralong copper nanowires (90-120 nm in diameter, 40-50 microm in length; aspect ratio >350-450) can be synthesized in large scale with a facile aqueous reduction route at low cost. The prepared copper nanowires can also be used as starting solid precursor for fabrication of polycrystalline oxide nanotubes via direct oxidation in air.     

Syntheses and structures of [M{In(SC{O}Ph)4}2] (M = Mg and Ca): single molecular precursors to MIn2S4 materials

The compounds [Mg{In(SC{O}Ph)4}2] (1) and [Ca(H2O)x{In(SC{O}Ph)4}2].yH2O (x = 0, y = 1, 2 major product; x = 1, y = 0, 2a minor product; x = 2, y = 2, 2b minor product) have been synthesized by reacting InCl3 and M(SC{O}Ph)2 (M = Mg and Ca) prepared in situ in the molar ratio 1:2. The structures of 1, 2a, and 2b have been determined by X-ray crystallography. The structure of 1 consists of two tetrahedral [In(SC{O}Ph)4]- anions sandwiching the Mg(II) metal ions through six carbonyl O atoms. The coordination geometry at the Mg(II) metal atom is distorted octahedral with an O(6) donor set. The structures of 2a and 2b consist of two [In(SC{O}Ph)4]- anions sandwiching the Ca(II) metal ion through five and four carbonyl O atoms, and the octahedral coordination at the Ca(II) centers is completed by one and two aqua ligands, respectively. Two aqua ligands and two lattice water molecules form a H-bonded water chain in the channel created by [Ca{In(SC{O}Ph)4}2] molecules in the crystal structure of 2b. The thermal decomposition of 1 and 2 indicated the formation of the corresponding MIn2S4 materials, and this was confirmed by X-ray powder diffraction patterns.     

Rapid method for quantifying the extent of methionine oxidation in intact calmodulin

We have developed a method for rapidly quantifying the extent to which the functionally important Met¹⁴⁴ and Met¹⁴⁵ residues near the C-terminus of calmodulin (CaM) are converted to the corresponding sulfoxides, Met(O). The method utilizes a whole protein collision-induced dissociation (CID) approach on an electrospray ionization quadrupole time-of-flight (ESI-Q-TOF) mass spectrometer. Using standards of CaM oxidized by hydrogen peroxide (H₂O₂) or peroxynitrite (ONOO⁻), we demonstrated that CID fragmentation of the protein ions resulted in a series of C-terminal singly charged y₁–y₁₅ ions. Fragments larger than y₄ exhibited mass shifts of +16 or +32 Da, corresponding to oxidation of one or two methionines, respectively. To assess the extent of oxidative modification for Met¹⁴⁴ and Met¹⁴⁵ to Met(O), we averaged the ratio of intensities for y _n , y _n + 16, and y _n + 32 ions, where n = 6–9. By alternating MS and CID scans at low and high collision energies, this technique allowed us to rapidly determine both the distribution of intact CaM oxiforms and the extent of oxidative modification in the C-terminal region of the protein in a single run. We have applied the method to studies of the repair of fully oxidized CaM by methionine sulfoxide reductases (MsrA and MsrB), which normally function in concert to reduce the S and R stereoisomers of methionine sulfoxide. We found that repair of Met(O)¹⁴⁴ and Met(O)¹⁴⁵ did not go to completion, but was more efficient than average Met repair. Absence of complete repair is consistent with previous studies showing that accumulation of methionine sulfoxide in CaM can occur during aging (Gao, J.; Yin, D.; Yao, Y.; Williams, T. D.; Squier, T. C. Biochemistry 1998, 37, 9536–9548).