Killing of organisms responsible for wound infections using a light-activated antimicrobial agent

Infected wounds are a major cause of hospital-acquired infections and these are difficult to treat due to the emergence of antibiotic-resistant bacteria. This project is concerned with evaluating a novel antimicrobial approach involving the photosensitizer indocyanine green (ICG) which generates reactive oxygen species when irradiated with near-infrared (NIR) light which enables good tissue penetration. The photo-susceptibility of common wound-infecting organisms to ICG coupled with NIR-light was investigated. All species were susceptible to killing. ICG at a concentration of 25 μg/mL enabled the killing of the Gram-positive species (Staphylococcus aureus and Streptococcus pyogenes), higher concentrations (100-200μg/mL) were necessary to achieve substantial kills of the Gram-negative species (Pseudomonas aeruginosa and Escherichia coli). Both high and low fluences were able to kill 99.999% of the Gram-positive bacteria. High fluence irradiation was necessary to kill 99.99% of the Gram-negative bacteria. The pulsed-mode of irradiation was as effective as the continuous-mode for killing the Gram-positive species. Yet only the continuous-mode of irradiation was able to kill P. aeruginosa. Biofilms of Staph. aureus and P. aeruginosa were susceptible to disruption and killing by ICG-photosensitization. A significant enhancement of lethal photosensitization of Staph. aureus was achievable using gold-nanoparticles and antioxidants. Significant kills (>99%) were achieved in the presence of serum and 100 μg/mL ICG. A low oxygen concentration reduced the kills to 96.77% and 71.62% for Staph. aureus and Strep. pyogenes respectively. Mechanistic studies revealed that killing was mediated mainly by reactive-oxygen species. In vivo studies in mice showed that ICG and continuous-NIR light could achieve kills of 96%, 93% and 78-91% for P. aeruginosa, Strep. pyogenes and Staph. aureus respectively. The results of these in vitro and in vivo studies imply that ICG-PDT could be an effective means of decreasing the microbial burden in wounds

Optimization of load balance link layer protocol for nodes with multiple channels and interfaces in wireless mesh networks: A comprehensive review

No Abstract

ANALISIS BEBERAPA FAKTOR YANG MEMPENGARUHI NILAI EKSPOR IKAN TUNA DI JAWA TIMUR KE JEPANG

Dalam pembangunan diarahkan untuk meningkatkan pendapatan taraf hidup petani dan nelayan memperluas lapangan kerja, dan kesempatan usaha serta dan memperluas pasar baik dalam negeri maupun luar negeri melaluu ekspor non migas terutama dibidang perikanan merupakan komoditas penghasil devisa terpenting selain hasil perkebunan dan kehutanan. Tidak berlebihan apabila dikatakan bahwa hasil perikanan merupakan mata dagang ekspor andalan disektor non migas volume dan nilai ekspor dari tahun ke tahun meningkat. Penelitian ini menggunakan data sekunder yang diperoleh dari badan pusat statistik Jawa Timur, Dinas Perikanan dan Dinas perindustrian dan perdagangan. Teknik analisis yang digunakan dalam penelitian ini adalah Regresi Linier Berganda dengan menggunakan alat bantu komputer Statistik Program for Social Science (SPSS) versi 12 yang menunjukkan pengaruh signifikan antara variabel bebas dan variabel terikat. Dari penelitian ini dapat disinpulkan bahwa variabel Kurs Valuta Asing, Inflasi Jepang, GPD Jepang, Produksi tidak terbukti kebenarannya semua, akan tetapi yang mempengaruhi hanya GPD Jepang dan Produksi dan produksi paling dominan terhadap nilai ekspor ikan tuna di Jawa Timur telah terbukti kebenarannya. Hal ini ditunjukkan dari hasil analisis dengan uji t untuk variabel diperoleh thitung sebesar 6,251 ≥ ttabel sebesar 2,228

Effect of Relative Humidity on Arctic Aerosols

In this paper, the authors investigated some microphysical and optical properties of arctic aerosols extracted from the data base Optical Properties of Aerosols and Clouds(OPAC) to determine the effect of hygroscopic growth at the spectral range of 0.25?m to 2.5?m and eight relative humilities (RHs) (0, 50, 70, 80, 90, 95, 98, and 99%).The microphysical properties extracted were radii, volume mix ratio, number mix ratio and mass mix ratio as a function of RH while the optical properties are scattering and absorption coefficients and asymmetric parameters. Using the microphysical properties, effective growth factors of the mixtures were determined while using optical properties enhancement parameters were determined and then parameterized using some models. We observed that the data fitted the models very well. The angstrom coefficients which determined the type of particles size distribution increases with the increase in RHs except at the delinquent point where it decreases with the increase in RHs. The mixture was determined to have bimodal type of distribution with the dominance of fine mode particles but non-spherical. Keywords: microphysical properties, optical properties, hygroscopic growth, enhancement parameters, models, parametrisation

Geometry optimization and vibrational frequencies of tetracene molecule in gas phase and in methanol based on Density Funtional Theory and Restricted Hartree-Fock

Tetracene is an organic semiconductor with chemical formula C18H12 used in organic field effecttransistor (OFET) and organic light emitting diode (OLED). In this work, the molecular geometry (optimized bond lengths and bond angles), vibrational frequencies and intensities, HOMO-LUMO Energy gap and Atomic charge distribution of the Tetracene molecule in gas phase and in solution were calculated and reported. Restricted Hartree-Fock (RHF) and Density Functional Theory (DFT) with different basis sets were employed for the task. Windows version of Gaussian 03 software was used to perform all the calculations. The results obtained show that the bond length obtained using RHF has the lowest average value of 1.072Å and that obtained using DFT has the lowest average value of 1.085Å in gas phase. In Methanol, it is observed that at RHF level, the lowest average value was 1.075Å and at DFT level was 1.087Å. This shows that the values are a bit higher in methanol than in gas phase which implies that the bonds will be slightly stronger in gas phase than in methanol. The strongest bonds in tetracene molecule are those of C20-H28, C23-H29 and C24- H30 in both gas and methanol. The weakest bonds are those of C6-C12 and C6-C14.The bond angles were found to be so closed to 1200 at both levels of theory for all basis sets used suggesting that the molecule is planar benzene in which the C atoms are sp2 hybridized. The calculated HOMOLUMO energy gap shows that the molecule will be slightly more stable in chemical reaction in gas phase than in methanol. DFT values of the energy gap appeared to be closer to the reported experimental value of 2.6eV than those obtained by RHF. The atomic charges distribution was found to be very sensitive to the basis sets which presumably occur due to polarization. From the results obtained for vibrational frequencies, it shows that tetracene molecule would be more stable in gas phase that in methanol as a result of no imaginary frequency found in gas phase. This confirms the stability of the molecule as stated in the results of HOMO-LUMO energy gap. The calculated vibrational frequencies show that the most intense frequency was obtained to be 924.9862cm-1 at 146.7973KM/mole by RHF/3-21G in gas phase while at B3LYP/3-21G, it has the most intense frequency of about 474.1260cm-1 at 390.1077.2845MK/mole in methanol.Keywords: Optimixation, Methanol, Gas, Frequency, Tetracen