Synthesis and Applications of Mutimodal Hybrid Albumin Nanoparticles for Chemotherapeutic Drug Delivery and Phototherml Therapy Platforms

Progress has been made in using human serum albumin nanoparticles (HSAPs) as carrier systems for targeted treatment of cancer. Human serum albumin (HSA), the most abundant human blood protein, can form HSAPs via a desolvation and crosslinking method, with the size of the HSAPs having crucial importance for drug loading and in vivo performance. Gold nanoparticles have also gained medicinal attention due to their ability to absorb near-infrared (NIR) light. These relatively non-toxic particles offer combinational therapy via imaging and photothermal therapy (PPTT) capabilities. A desolvation and crosslinking approach was employed to encapsulate gold nanoparticles (AuNPs), hollow gold nanoshells (AuNSs), and gold nanorods (AuNRs), into efficiently sized HSAPs for future tumor heat ablation via PPTT. The AuNR-HSAPs, AuNP-HSAPs and AuNS-HSAPs had average particle diameters of 222 ± 5, 195 ± 9 and 156 ± 15, respectively. We simultaneously encapsulated AuNRs and the anticancer drug paclitaxel (PAC), forming PAC-AuNR-HSAPs with overall average particle size of 299 ± 6 nm. Loading of paclitaxel into PAC-AuNR-HSAPs reached 3μg PAC/mg HSA. PAC-AuNR-HSAPs experienced photothermal heating of 46 ˚C after 15 minutes of NIR laser exposure; the temperature necessary to cause severe cellular hyperthermia. There was a burst release of paclitaxel up to 188 ng caused by the irradiation session, followed by a temporal drug release. AuNR-HSAPs were tested for ablation of renal cell carcinoma using NIR irradiation in vitro. Particles created with the same amount of AuNRs, but varying HSA (1, 5 or 20 mg) showed overall particle size diameters 409 ± 224, 294 ± 83 and 167 ± 4 nm, respectively. Increasing HSAPs causes more toxicity under non-irradiated treatment conditions: AuNR-HSAPs with 20 mg versus 5 mg HSA caused cell viability of 64.5% versus 87%, respectively. All AuNR-HSAPs batches experienced photothermal heating above 42 ˚C. Coumarin-6, was used to visualize the cellular uptake of AuNR-HSAPs via fluorescence microscopy. Finally, camptothecin (CPT) an antineoplastic agent and BACPT (7-butyl-10-aminocamptothecin) were loaded into HSAPs to combat their aqueous insolubility. BACPT-HSAPs loaded up to 5.25 micrograms BACPT/ mg of HSA. CPT encapsulation could not be determined. BACPT-HSAPs and CPT-HSAPs showed cytotoxicity to human sarcoma cells in vitro

Gravitational radiation from pulsar glitches

The nonaxisymmetric Ekman flow excited inside a neutron star following a rotational glitch is calculated analytically including stratification and compressibility. For the largest glitches, the gravitational wave strain produced by the hydrodynamic mass quadrupole moment approaches the sensitivity range of advanced long-baseline interferometers. It is shown that the viscosity, compressibility, and orientation of the star can be inferred in principle from the width and amplitude ratios of the Fourier peaks (at the spin frequency and its first harmonic) observed in the gravitational wave spectrum in the plus and cross polarizations. These transport coefficients constrain the equation of state of bulk nuclear matter, because they depend sensitively on the degree of superfluidity.Comment: 28 page

Nonadiabatic charged spherical evolution in the postquasistatic approximation

We apply the postquasistatic approximation, an iterative method for the evolution of self-gravitating spheres of matter, to study the evolution of dissipative and electrically charged distributions in General Relativity. We evolve nonadiabatic distributions assuming an equation of state that accounts for the anisotropy induced by the electric charge. Dissipation is described by streaming out or diffusion approximations. We match the interior solution, in noncomoving coordinates, with the Vaidya-Reissner-Nordstr\"om exterior solution. Two models are considered: i) a Schwarzschild-like shell in the diffusion limit; ii) a Schwarzschild-like interior in the free streaming limit. These toy models tell us something about the nature of the dissipative and electrically charged collapse. Diffusion stabilizes the gravitational collapse producing a spherical shell whose contraction is halted in a short characteristic hydrodynamic time. The streaming out radiation provides a more efficient mechanism for emission of energy, redistributing the electric charge on the whole sphere, while the distribution collapses indefinitely with a longer hydrodynamic time scale.Comment: 11 pages, 16 Figures. Accepted for publication in Phys Rev

Algoritmos paralelos para la resolución de ecuaciones diferenciales ordinarias mediante OpenMP

Proceeding of: XIV Jornadas de Paralelismo, Leganés, Madrid (Spain), 15-17, septiembre, 2003En los últimos años está adquiriendo un gran auge el estudio de los métodos numéricos para la resolución Ecuaciones Diferenciales Ordinarias (ODE’s). Muchos de los métodos numéricos existentes se basan en la aproximación de un modelo continuo mediante un modelo discreto y el cálculo de una solución aproximada en un conjunto finito de puntos. En [1] se presenta una nueva aproximación al cálculo de ODE’s donde la principal aportación pasa por permitir una solución del problema independientemente de que el Jacobiano sea o no invertible. En el presente trabajo se presenta un nuevo algoritmo basado en [1] que permite la resolución de ODE’s. Además, se ha llevado a cabo una implementación paralela sobre arquitecturas de memoria compartida de dicho algoritmo. Tanto el algoritmo secuencial como el algoritmo paralelo desarrollado se han implementado utilizando librerías estándar tanto en el cómputo como en la comunicación en aras de obtener portabilidad, robustez y eficiencia

Buds, main reserve of yeasts between vegetative and reproductive aerial organs of Vitis vinifera var. Malbec.

El objetivo de esta investigación fue suministrar nueva evidencia acerca del modelo de permanencia de las levaduras en el ciclo natural de la vid. Se efectuó la observación, la medición del número de levaduras y la descripción morfológica de los diferentes órganos aéreos de la vid. Se procedió a la recolección aséptica de muestras a campo, en yema en actividad, yema en reposo, hoja joven, hoja adulta, ritidomis, zarcillo, capullo floral, flor y fruto. Los resultados revelaron dos momentos de máxima población de levaduras: en yema cerrada a fines de otoño y en yema terminal abierta a mediados de verano. La evolución de las levaduras en función de la superficie del fruto mostró poca relación entre ambas variables, por lo que el valor a considerar sería la cantidad de levaduras por baya como unidad. La ritidomis exhibió valores muy uniformes a lo largo del ciclo vegetativo, asumiendo desde esta perspectiva el papel de reservorio de moderada importancia.The objective of this investigation was to provide new evidence about the model of permanence of yeasts of the grapevine in the natural cycle. It was carried out the observation, measurement of number and morphologic description of different aerial organs from the grapevine. It was come to the aseptic harvesting from samples in field of bud in activity, bud in rest, young leaf, adult leaf, bark, tendril, flower bud, flower, fruit. The results revealed two moments of maximum population of yeasts: in closed bud by the end of autumn and opened terminal bud in the middle of summer. The evolution of yeasts in the fruit referred to the surface of the berry showed little relation between both variables, whereas the value to consider would be the amount of yeasts by berry as unit. Bark displayed very uniform values throughout the vegetative cycle, assuming from this perspective the role of reserve of moderate importance.Fil: Lúquez Bibiloni, Claudia V.. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ciencias BiológicasFil: Formento, Juan Carlos. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ciencias Enológicas y AgroalimentariasFil: Díaz Peralta, Eduardo. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ciencias Enológicas y Agroalimentaria

Spin polarization induced by decoherence in a tunneling one-dimensional Rashba model

Basic questions on the nature of spin polarization in two terminal systems and the way in which decoherence breaks Time-Reversal Symmetry (TRS) are analyzed. We exactly solve several one-dimensional models of tunneling electrons and show the interplay of spin precession and decay of the wavefunction in either a U(1) magnetic field or an effective Spin-Orbit (SO) magnetic field. Spin polarization is clearly identified as the emergence of a spin component parallel to either magnetic field. We show that Onsager's reciprocity is fulfilled when time reversal symmetry is present and no spin polarization arises, no matter the barrier parameters or the SO strength. Introducing a Buttiker's decoherence probe, that preserves unitarity of time evolution, we show that breaking of TRS results in a strong spin polarization for realistic SO, and barrier strengths. We discuss the significance of these results as a very general scenario for the onset of the Chiral-Induced Spin Selectivity effect (CISS), now possibly matching experiments in a quantitative manner.Comment: 24 pages, 14 figure

SSTAR Users Manual

There are four objective functions available to date (11/86), these include 1) maximimize total regional groundwater withdrawl. 2) minimize total coat of satisfying regional needs. and 3) maximize the sum of selected local withdrawls. and 4) maximize the present value of total net economic return

Avalanche dynamics of radio pulsar glitches

We test statistically the hypothesis that radio pulsar glitches result from an avalanche process, in which angular momentum is transferred erratically from the flywheel-like superfluid in the star to the slowly decelerating, solid crust via spatially connected chains of local, impulsive, threshold-activated events, so that the system fluctuates around a self-organised critical state. Analysis of the glitch population (currently 285 events from 101 pulsars) demonstrates that the size distribution in individual pulsars is consistent with being scale invariant, as expected for an avalanche process. The waiting-time distribution is consistent with being exponential in seven out of nine pulsars where it can be measured reliably, after adjusting for observational limits on the minimum waiting time, as for a constant-rate Poisson process. PSR J0537$-$6910 and PSR J0835$-$4510 are the exceptions; their waiting-time distributions show evidence of quasiperiodicity. In each object, stationarity requires that the rate $\lambda$ equals $- \epsilon \dot{\nu} /$, where $\dot{\nu}$ is the angular acceleration of the crust, $$ is the mean glitch size, and $\epsilon\dot{\nu}$ is the relative angular acceleration of the crust and superfluid. There is no evidence that $\lambda$ changes monotonically with spin-down age. The rate distribution itself is fitted reasonably well by an exponential for $\lambda \geq 0.25 {\rm yr^{-1}}$. For $\lambda < 0.25 {\rm yr^{-1}}$, its exact form is unknown; the exponential overestimates the number of glitching pulsars observed at low $\lambda$, where the limited total observation time exercises a selection bias.Comment: Accepted for publication in the Astrophysical Journa