Algorytm pszczeli w optymalizacji modelu przepływowego szeregowania zadań

Problem of optimization with limited resources is fundamental one in computer sciences. The bees algorithm from wider group of swarm algorithms, invented and implemented about 2005, seems to be a good candidate for next useful tool for combinatorial optimization. Article presents the results of the bees algorithm research in flow shop model of task scheduling and outlines areas of further exploration.Problem optymalizacji przy ograniczonych zasobach jest jednym z podstawowych tematów w informatyce. Algorytm pszczeli z szerszej grupy algorytmów stadnych, wynaleziony i przedstawiony w połowie ostatniej dekady, wydaje się być obiecującym narzędziem w optymalizacji kombinatorycznej. Artykuł przedstawia wyniki badań nad algorytmem w optymalizacji modelu przepływowego szeregowania zadań i zakreśla dalsze ich obszary

Mechanism of active targeting in solid tumors with transferrin-containing gold nanoparticles

PEGylated gold nanoparticles are decorated with various amounts of human transferrin (Tf) to give a series of Tf-targeted particles with near-constant size and electrokinetic potential. The effects of Tf content on nanoparticle tumor targeting were investigated in mice bearing s.c. Neuro2A tumors. Quantitative biodistributions of the nanoparticles 24 h after i.v. tail-vein injections show that the nanoparticle accumulations in the tumors and other organs are independent of Tf. However, the nanoparticle localizations within a particular organ are influenced by the Tf content. In tumor tissue, the content of targeting ligands significantly influences the number of nanoparticles localized within the cancer cells. In liver tissue, high Tf content leads to small amounts of the nanoparticles residing in hepatocytes, whereas most nanoparticles remain in nonparenchymal cells. These results suggest that targeted nanoparticles can provide greater intracellular delivery of therapeutic agents to the cancer cells within solid tumors than their nontargeted analogs

STUDY CORRELATING NIOBIUM SURFACE ROUGHNESS WITH SURFACE PARTICLE COUNTS

Abstract A study has been initiated at Michigan State University (MSU) to relate the surface preparation of Superconducting Radio Frequency (SRF) resonators and surface particle counts, using niobium samples. During fabrication, undesired surface roughness can develop on the internal surfaces of the resonators. The final cavity finish will be product of material forming, machining, welding, chemistry, high-pressure rinsing, and handling of the niobium material. This study will document niobium samples treated with MSU standard processing procedures; first measuring the surface roughness, then polishing samples with defined techniques, processing, and measuring surface particle counts. The samples will include as received niobium, machined surfaces, welded surfaces, and surfaces with characterized surface imperfections (scratches)

LUMINESCENCE QUANTUM EFFICIENCY OF Mn2 + STATES IN ZnSe:Mn AS STUDIED BY MEANS OF PHOTOACOUSTIC SPECTROSCOPY*

The photoacoustic spectroscopy with a piezoelectric transducer was employed to determined the quantum efficiency for low Mn concentration in ZnSe monocrystals. The photoacoustic spectra were measured using the continuous wave excitation and nanosecond pulse method. PACS numbers: 43.85.+f, 62.65.+k, 78.20.Ηρ The determination of absolute luminescence quantum efficiency (QE) of ions in solids is important in both technology and basic physics. The photoacoustic spectroscopy (PAS) has been used quite successfully to obtain accurate absolute radiative quantum efficiency in solids because it does not require absolute calibration of the detector or knowledge of absolute ion concentration [4] applied the transducer PZT (piezoelectric transducer) method which enables one to measure the structured PΑ spectra. In this paper we describe the first determination of QE of ZnSeMn with low concentration (nΜn = 0.02 mol%). The samples used in our investigations were single crystals of ZnSe doped with Mn grown by high pressure Bridgmann method. For growing the Koch-Light 6N ZnSe powder has been used. The excitation spectra were obtained by visible lines of an Ar+ laser (458 to 514 nm) at 300 K and 77 K. The gated photon counting system (Stanford SR 400) measured the intensity of the signal by counting the number of photons which were detected by a Hamamatsu R94302 photomultiplier in a given time gate

Dewar Testing of Coaxial Resonators at MSU

Michigan State University is currently testing prototype and production cavities for two accelerator projects. 80.5 MHz {beta} = 0.085 quarter wave resonators (QWR) are being produced as part of a cryomodule for ReA3. 322 MHz {beta} = 0.53 half wave resonators (HWR) are being prototyped for a driver linac for the Facility for Rare Isotope Beams. This paper will discuss test results and how different cavity preparations effect cavity performs. Also various diagnostics methods have been developed, such as second sound quench location determination, and temperature mapping to determine hot spots from defects and multipacting location

Advances of the FRIB project

The Facility for Rare Isotope Beams (FRIB) Project has entered the phase of beam commissioning starting from the room-temperature front end and the superconducting linac segment of first 15 cryomodules. With the newly commissioned helium refrigeration system supplying 4.5K liquid helium to the quarter-wave resonators and solenoids, the FRIB accelerator team achieved the sectional key performance parameters as designed ahead of schedule accelerating heavy ion beams above 20MeV/u energy. Thus, FRIB accelerator becomes world's highest-energy heavy ion linear accelerator. We also validated machine protection and personnel protection systems that will be crucial to the next phase of commissioning. FRIB is on track towards a national user facility at the power frontier with a beam power two orders of magnitude higher than operating heavy-ion facilities. This paper summarizes the status of accelerator design, technology development, construction, commissioning as well as path to operations and upgrades

Tissue-Specific Gene Delivery via Nanoparticle Coating

Author Manuscript: 2010 August 1.The use of biomaterials for gene delivery can potentially avoid many of the safety concerns with viral gene delivery. However, the efficacy of polymeric gene delivery methods is low, particularly in vivo. One significant concern is that the interior and exterior composition of polymeric gene delivery nanoparticles are often coupled, with a single polymer backbone governing all functions from biophysical properties of the polymer/DNA particle to DNA condensation and release. In this work we develop electrostatically adsorbed poly(glutamic acid)-based peptide coatings to alter the exterior composition of a core gene delivery particle and thereby affect tissue-specificity of gene delivery function in vivo. We find that with all coating formulations tested, the coatings reduce potential toxicity associated with uncoated cationic gene delivery nanoparticles following systemic injection. Particles coated with a low 2.5:1 peptide:DNA weight ratio (w/w) form large 2 μ sized particles in the presence of serum that can facilitate specific gene delivery to the liver. The same particles coated at a higher 20:1 w/w form small 200 nm particles in the presence of serum that can facilitate specific gene delivery to the spleen and bone marrow. Thus, variations in nanoparticle peptide coating density can alter the tissue-specificity of gene delivery in vivo.National Institutes of Health (U.S.) (BRP: 1R01CA124427-01)National Institutes of Health (U.S.) (EB 000244)National Institutes of Health (U.S.) (U54 CA119349-01)David & Lucile Packard Foundation (Fellowship 1999-1453A

Superconducting Resonators Development for the FRIB and ReA Linacs at MSU: Recent Achievements and Future Goals

The superconducting driver and post-accelerator linacs of the FRIB project, the large scale radioactive beam facility under construction at MSU, require the construction of about 400 low-{beta} Quarter-wave (QWR) and Half-wave resonators (HWR) with four different optimum velocities. 1st and 2nd generation prototypes of {beta}{sub 0} = 0.041 and 0.085 QWRs and {beta}{sub 0} = 0.53 HWRs have been built and tested, and have more than fulfilled the FRIB and ReA design goals. The present cavity surface preparation at MSU allowed production of low-{beta} cavities nearly free from field emission. The first two cryostats of {beta}{sub 0} = 0.041 QWRs are now in operation in the ReA3 linac. A 3rd generation design of the FRIB resonators allowed to further improve the cavity parameters, reducing the peak magnetic field in operation and increasing the possible operation gradient, with consequent reduction of the number of required resonators. The construction of the cavities for FRIB, which includes three phases for each cavity type (development, pre-production and production runs) has started. Cavity design, construction, treatment and performance will be described and discussed

I. Structural Effects of Carbohydrate-Containing Polycations on Gene Delivery. II. Development of a Nanoparticle-Based Model Delivery System to Guide the Rational Design of Gene Delivery to the Liver

Linear cationic beta-cyclodextrin (b-CD)-based polymers can bind with plasmid DNA to form colloid-sized composite particles that transfect cultured cells. In the first part of this thesis, synthetic variations of the b-CD structure are used to probe structure-function gene delivery properties. The type of cyclodextrin and its functionalization are investigated by synthesizing numerous 3A,3B-dideoxy-3A,3B-diamino-b- and g-CD monomers, which are polymerized with dimethyl suberimidate to yield amidine-based polycations. The nature of the spacer between the CD-ring and the primary amines of each monomer is found to influence both molecular weight and polydispersity of the polycations. When complexed with plasmid DNA, polycations with longer alkyl regions between the CD and the charge centers show increased transfection efficiency and toxicity in BHK-21 cells. More hydrophilic spacers resulted in lower toxicity, and g-CD-based polycations were less toxic than otherwise identical b-CD-based polycations. In the second part of this thesis, a model delivery system is developed that can mimic the size and surface properties of the cyclodextrin-based gene-delivery particles, and this system is used to define design constraints that should be applied to next generation gene delivery particles targeted to the liver. Gal-50 and Gal-140 are galactosylated 50 nm and 140 nm nanoparticles that have the same surface galactose density, while MeO-50 and MeO-140 are methoxy-terminated 50 nm and 140 nm nanoparticles. All four particles have the same surface charge and resist aggregation in serum. In freshly isolated hepatocytes, Gal-50 nanoparticles are taken up to a greater extent than are MeO-50, but both 50 nm beads are taken up to a much greater extent than are either of the 140 nm nanoparticles. TEM and immunohistochemistry confirm that Gal-140 nanoparticles are primarily internalized by Kupffer cells, though isolated examples of a few Gal-140 in hepatocytes can also be found. On the other hand, Gal-50 nanoparticles are overwhelmingly found in vesicles throughout the cytoplasm of hepatocytes, with only isolated examples of Kupffer cell uptake. As such, it is clear that slightly anionic, galactose-PEGylated nanoparticles should be about 50 nm in diameter to preferentially target hepatocytes while they should be about 140 nm in diameter to selectively target Kupffer cells.</p