Current approach to the management of gastrinoma and insulinoma in adults with multiple endocrine neoplasia type I

Although there is a recent increase in the use of the isolated pancreatic islets of the rat in the transplantation and functional studies, there has been no detailed quantitative assessment on the size and cellular constituents of islets after the isolation procedure. The present work was undertaken to study the size classes of the isolated islets and the morphometry of their cellular populations. Islets of the rat pancreas were isolated by using the intraductal collagenase digestion technique, the most commonly used procedure for the isolation of pancreatic islets. Different endocrine cells of the isolated islets were stained by immunoperoxidase staining techniques. The distribution of the cellular constituents of the isolated islets was similar to that of the intact islets of the normal pancreas; A, D, and PP cells were peripherally arranged around the centrally located B cells. However, morphometric quantitative study showed that the percent volume and percent number of A, D, and PP cells of the isolated islets were lower than those of the corresponding intact ones. Further, the mean true diameter of the isolated islets was lower than that of the intact ones. These data indicate loss of islet cells during the process of isolation. Most of the lost cells were from the periphery of islets. This may provide an explanation for the incomplete metabolic control and recurrence of hyperglycemia encountered after isolated islet transplantation in the treatment of diabetes mellitus. It seems that further refinements of the isolation techniques are necessary to obtain islet tissue with total cellular integrity, before a complete success in transplantation could be achieved.     

Microscopic Origin of Casimir-Polder Forces

We establish a general relation between dispersion forces. First, based on QED in causal media, leading-order perturbation theory is used to express both the single-atom Casimir-Polder and the two-atom van der Waals potentials in terms of the atomic polarizabilities and the Green tensor for the body-assisted electromagnetic field. Endowed with this geometry-independent framework, we then employ the Born expansion of the Green tensor together with the Clausius-Mosotti relation to prove that the macroscopic Casimir-Polder potential of an atom in the presence of dielectric bodies is due to an infinite sum of its microscopic many-atom van der Waals interactions with the atoms comprising the bodies. This theorem holds for inhomogeneous, dispersing, and absorbing bodies of arbitrary shapes and arbitrary atomic composition on an arbitrary background of additional magnetodielectric bodies.     

Signature analysis and defect detection in layered manufacturing of ceramic sensors and actuators

This paper presents the concept of a process signature for the use of online signature analysis and defect detection in the layered manufacturing (LM) of ceramic sensors and actuators. To achieve the high quality of parts built by the fused deposition of ceramics (FDC), an online process-monitoring system is implemented to detect the processing defects. Using a process signature extracted from the image of a layer captured by the monitoring system, an ideal image is created that is then compared to the original image to detect and identify the defects. Some results of signature analysis and defect detection for single-material and multi-material parts are also presented.Received: 22 July 1999, Accepted: 21 October 2001, Published online: 29 October 2003 Correspondence to: Mohsen A. JafariThis work was supported by the Office of Naval Research under grant # N-0014-96-1-1175. Ref. US Patent # S-5738817, April 14, 1998.     

The stability of duplexes involving AT and/or G4EtC base pairs is not dependent on their AT/G4EtC ratio content. Implication for DNA sequencing by hybridization

Sequencing by the recently reported hybridization technique requires the formation of DNA duplexes with similar stabilities. In this paper we describe a new strategy to obtain DNA duplexes with a thermal stability independent of their AT/GC ratio content. Melting data were acquired on 35 natural and 27 modified duplexes of a given length and of varying base compositions. Duplexes built with AT and/or G4EtC base pairs exhibit a thermal stability restrained to a lower range of temperature than that of the corresponding natural compounds (16 instead of 51 degrees C). The 16 degrees C difference in thermal stability observed between the least stable and the most stable duplex built with AT and/or G4EtC base pairs is mainly due to the sequence effect and not to their AT/G4EtC ratio content. Thus N -4-ethyl-2'-deoxycytidine (d4EtC) hybridizes specifically with natural deoxyguanosine leading to a G4EtC base pair whose stability is very close to that of the natural AT base pair. Oligonucleotide probes involving d4EtC can be easily prepared by chemical synthesis with phosphoramidite chemistry. Modified DNA targets were successfully amplified by random priming or PCR techniques using d4EtCTP, dATP, dGTP and dTTP in the presence of DNA polymerase. This new system might be very useful for DNA sequencing by hybridization.     

Investigation into the automatic drilling of cortical bones using ANFIS-PSO and sensitivity analysis

Neural Computing and Applications - During the bone drilling process, in case of excessive force can cause breakage, crack initiation and severe damage to bone tissue. Additionally, if drilling...     

Overview of Fine-Scale Piezoelectric Ceramic/Polymer Composite Processing

In the past two decades, piezoelectric ceramic/polymer composites with different connectivities have been developed for transducer applications such as hydrophones, biomedical imaging, nondestructive testing, and air imaging. Recently, much attention has been given to fine-scale piezoelectric ceramic/polymer composites. These composites allow higher operating frequencies, and thus increased resolution, in medical imaging transducers. In this review, methods for processing fine-scale piezoelectric ceramic/polymer composites are discussed. The current capabilities, strengths, and weaknesses of each method are compared. The importance of spatial scale in composite performance is also reviewed. Several of the processing methods have demonstrated composites with fine-scale ceramic phases (<50 μm), and others have potential to form composites with a ceramic scale of under 20 μm.     

Effect of Composition on the Electromechanical Properties of (1-x)Pb(Mg1/3Nb2/3)O3−XPbTiO3 Ceramics

Ceramic lead magnesium niobate–lead titanate ((1-x)PMN_-xPT) of different compositions has been prepared by the columbite precursor method. This study discusses compositions ranging from 0.94PMN–0.06PT to 0.60PM–N0.40PT, focusing on two areas of the (1-x)PMN_xPT system: compositions that exhibit electrostrictive behavior, and those that show piezoelectric behavior. In electrostrictive compositions where x is in the range of 0.06–0.20, the dielectric constant and electromechanical coupling factor dependencies on the bias field are evaluated. The optimal electromechanical properties are obtained with the composition 0.82PMN–0.18PT, measured at temperature T = T_m (the temperature of maximum dielectric constant) = 80°C and with a dc bias of 5 kV/cm. X–ray diffractometry is used to show that the (1-x)PMN_-xPT system has a compositionally wide two–phase region and that 0.655PMN–0.345PT is the morphotropic phase boundary (MPB) composition. Electromechanical property evaluation shows that the optimal piezoelectric properties (piezoelectric charge coefficient ( d₃₃ ) value of 720 pC/N, dielectric constant ( K ) value of 5400, and electromechanical planar and thickness coupling coefficient ( k_p and k_t , respectively) values of 62% and 46%, respectively) are obtained at the MPB composition.     

Correct program parallelisations

International Journal on Software Tools for Technology Transfer - A commonly used approach to develop deterministic parallel programs is to augment a sequential program with compiler directives...     

Investigation of effective dimensionless numbers on initiation of instability in combustion of moisty organic dust简

In this work, the effect of various effective dimensionless numbers and moisture contents on initiation of instability in combustion of moisty organic dust is calculated. To have reliable model, effect of thermal radiation is taken into account. One- dimensional flame structure is divided into three zones： preheat zone, reaction zone and post-flame zone. To investigate pulsating characteristics of flame, governing equations are rewritten in dimensionless space-time （（, r/, ~） coordinates. By solving these newly achieved governing equations and combining them, which is completely discussed in body of article, a new expression is obtained. By solving this equation, it is possible to predict initiation of instability in organic dust flame. According to the obtained results by increasing Lewis number, threshold of instability happens sooner. On the other hand, pulsating is postponed by increasing Damk6hler number, pyrolysis temperature or moisture content. Also, by considering thermal radiation effect, burning velocity predicted by our model is closer to experimental results.     

Nonlinear Interval Parameter Programming Combined with Cooperative Games: a Tool for Addressing Uncertainty in Water Allocation Using Water Diplomacy Framework

Water Resources Management - This paper shows the utility of a new interval cooperative game theory as an effective water diplomacy tool to resolve competing and conflicting needs of water users...