Permittivity and permeability measurement of microwave packaging materials

There has recently been a growing interest in using new packaging materials-dielectric and/or magnetic-in a wide variety of applications for controlling the microwave heating of food. The study of the thermal behavior of these products requires the accurate determination of the complex permittivity and permeability when the temperature varies, and when the materials are irradiated in specific conditions. One of the main challenges is to distinguish the dielectric losses from the magnetic ones. In this paper, a practical measurement method is proposed, which consists of irradiating a rod sample successively with a homogeneous electric-field distribution with a low magnetic field and with a homogeneous magnetic-field distribution with low electric field. An accurate and efficient electromagnetic analysis tool is used to generate a set of points, which allow the construction of several bilinear functions that relate the scattering parameters of the circuit to the complex values of /spl epsiv/ and /spl mu/ so that /spl epsiv/ and /spl mu/ can then be easily determined from experimental measurements in accordance to whatever the special irradiation conditions. Some results for test materials are presented and discussed.     

PASHEMOS: a versatile program written in Pascal to simulate patterns on the shells of molluscs, according to the Meinhardt model

In this paper we describe PASHEMOS, a user-friendly program written in Pascal to solve the Meinhardt-Klingler model numerically. This model studies the shell pattern pigmentation of molluscs. Moreover, PASHEMOS enables theoretical analysis to be performed on the different steady states. The program takes into account the four differential equation systems established in the model. It numerically solves these systems. This program is developed in such a way that both the equation system type and the parameter values can be chosen. The pattern is displayed in each case, and other output possibilities are available (i.e. three-dimensional concentration plotting, phase plane, phase space, stability analysis). The implementation of the program for the case of a three-variable system is shown as an example of PASHEMOS handling. Program applications for other models are also discussed.     

HIV-1 and HTLV-I in sexually transmitted disease clinics in the Dominican Republic

Emergency air medical transport has become an integral part of the practice of medicine. In 1990, there were more than 170 air medical programs in operation in the United States. The proper and safe use of air medical transport requires a basic understanding of the medical implications of flight and the capabilities and constraints involved in transporting patients by air. The purpose of this paper is to review this information and provide guidelines for the use of air medical transport.     

KAR1-MEDIATED TRANSFORMATION OF BREWING YEAST

Transfer of plasmid between nuclei has been observed in heterokaryons obtained from kar1 × KAR1 crosses³. On this basis, brewing yeast strain CC45 was forced to mate with K5-5A, a kar1 laboratory strain bearing plasmid YEpCR21. This multicopy plasmid carries the gene cyh2 and determines a dominant resistance to cycloheximide . Heteroplasmons having a CC45 nucleus and hosting YEpCR21 were obtained. Plasmid stability and brewing performance have been studied. The utility of kar1-mediated plasmid transference as an alternative method to transform brewing yeast is discussed. Advantages of YEpCR21 as a vector cloning for brewing yeast are considered as well .     

Influence of Na deposition on convoy-electron emission

The influence of surface properties on convoy-electron emission from a sputter-clean Al foil induced by H⁺ has been studied under ultrahigh-vacuum conditions. It is found that the convoy-electron yield depends strongly on the Na coverage when the downstream surface is modified by controlled Na deposition. It can be concluded that an increasing yield is observed for larger work-function values.     

Silhouette and stereo fusion for 3D object modeling

In this paper, we present a new approach to high quality 3D object reconstruction. Starting from a calibrated sequence of color images, the algorithm is able to reconstruct both the 3D geometry and the texture. The core of the method is based on a deformable model, which defines the framework where texture and silhouette information can be fused. This is achieved by defining two external forces based on the images: a texture driven force and a silhouette driven force. The texture force is computed in two steps: a multi-stereo correlation voting approach and a gradient vector flow diffusion. Due to the high resolution of the voting approach, a multi-grid version of the gradient vector flow has been developed. Concerning the silhouette force, a new formulation of the silhouette constraint is derived. It provides a robust way to integrate the silhouettes in the evolution algorithm. As a consequence, we are able to recover the contour generators of the model at the end of the iteration process. Finally, a texture map is computed from the original images for the reconstructed 3D model.     

Active Delivery of VLPs Promotes Anti‐Tumor Activity in a Mouse Ovarian Tumor Model

Virus‐like nanoparticles (VLPs) have been used as an attractive means in cancer immunotherapy because of their unique intrinsic immunostimulatory properties. However, for treating metastatic tumors in the peritoneal cavity, such as ovarian cancer, multiple injections of therapy are needed due to the large peritoneal space and fast excretion of therapy. Here, it is reported on the development of active VLP delivery vehicles for the treatment of peritoneal ovarian tumors using biocompatible Qβ VLPs‐loaded Mg‐based micromotors. The autonomous propulsion of such Qβ VLPs‐loaded Mg‐micromotors in the peritoneal fluid enables active delivery of intact immunostimulatory Qβ VLPs to the peritoneal space of ovarian tumor bearing mice, greatly enhancing the local distribution and retention of Qβ VLPs. Such improved distribution and longer retention time of Qβ in the peritoneal cavity leads to enhanced immunostimulation and therefore increased survival rate of tumor‐bearing mice compared to a passive Qβ treatment. For clinical translation, the active delivery of VLPs holds great promise for tumor immunotherapy toward the treatment of different types of primary and metastatic tumors in the peritoneal cavity.     

A Macrophage–Magnesium Hybrid Biomotor: Fabrication and Characterization

Magnesium (Mg)‐based micromotors are combined with live macrophage (MΦ) cells to create a unique MΦ–Mg biohybrid motor system. The resulting biomotors possess rapid propulsion ability stemming from the Mg micromotors and the biological functions provided by the live MΦ cell. To prepare the biohybrid motors, Mg microparticles coated with titanium dioxide and poly(l ‐lysine) (PLL) layers are incubated with live MΦs at low temperature. The formation of such biohybrid motors depends on the relative size of the MΦs and Mg particles, with the MΦ swallowing up Mg particles smaller than 5 µm. The experimental results and numerical simulations demonstrate that the motion of MΦ–Mg motors is determined by the size of the Mg micromotor core and the position of the MΦ during the attachment process. The MΦ–Mg motors also perform biological functions related to free MΦs such as endotoxin neutralization. Cell membrane staining and toxin neutralization studies confirm that the MΦs maintain their viability and functionality (e.g., endotoxin neutralization) after binding to the Mg micromotors. This new MΦ–Mg motor design can be expanded to different types of living cells to fulfill diverse biological tasks.