A Fiber-Rich Diet and Radiation-Induced Injury in the Murine Intestinal Mucosa

Dietary fiber is considered a strong intestinal protector, but we do not know whether dietary fiber protects against the long-lasting mucosal damage caused by ionizing radiation. To evaluate whether a fiber-rich diet can ameliorate the long-lasting pathophysiological hallmarks of the irradiated mucosa, C57BL/6J mice on a fiber-rich bioprocessed oat bran diet or a fiber-free diet received 32 Gray in four fractions to the distal colorectum using a linear accelerator and continued on the diets for one, six or 18 weeks. We quantified degenerating crypts, crypt fission, cell proliferation, crypt survival, macrophage density and bacterial infiltration. Crypt loss through crypt degeneration only occurred in the irradiated mice. Initially, it was most frequent in the fiber-deprived group but declined to levels similar to the fiber-consuming group by 18 weeks. The fiber-consuming group had a fast response to irradiation, with crypt fission for growth or healing peaking already at one week post-irradiation, while crypt fission in the fiber-deprived group peaked at six weeks. A fiber-rich diet allowed for a more intense crypt cell proliferation, but the recovery of crypts was eventually lost by 18 weeks. Bacterial infiltration was a late phenomenon, evident in the fiber-deprived animals and intensified manyfold after irradiation. Bacterial infiltration also coincided with a specific pro-inflammatory serum cytokine profile. In contrast, mice on a fiber-rich diet were completely protected from irradiation-induced bacterial infiltration and exhibited a similar serum cytokine profile as sham-irradiated mice on a fiber-rich diet. Our findings provide ample evidence that dietary fiber consumption modifies the onset, timing and intensity of radiation-induced pathophysiological processes in the intestinal mucosa. However, we need more knowledge, not least from clinical studies, before this finding can be introduced to a new and refined clinical practice.     

Tracking filter and multi-sensor data fusion

In this paper factorization filtering, fusion filtering strategy and related algorithms are presented. Some results of implementation and validation using realistic data are given.     

Low‐density polyethylene/plasticized tapioca starch blends with the low‐density polyethylene functionalized with maleate ester: Mechanical and thermal properties

In this study, the mechanical and thermal properties of low‐density polyethylene (LDPE)/thermoplastic tapioca starch blends were determined with LDPE‐g‐dibutyl maleate as the compatibilizer. Mechanical testing for the evaluation of the impact strength and tensile properties was carried our as per standard ASTM methods. Thermogravimetric analysis and differential scanning calorimetry were also used to assess the thermal degradation of the blends. Scanning electron micrographs were used to analyze fracture and blend morphologies. The results show significant improvement in the mechanical properties due to the addition of the compatibilizer, which effectively linked the two immiscible blend components. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1109–1120, 2006     

In-vitro crystallization of spherulites of monosodium urate monohydrate

Sherulitic and an aggregate of bow shaped crystals of monosodium urate monohydrate which had a close resemblance to that of those crystals found in gouty synovial fluids and articular cartilage have been grown using tetramethoxysilane and silica gel.Thermogravimetric analysis (TGA), and infrared (IR) and X-ray diffraction were used to analyse the grown samples. Crystals were obtained for a wide range of pH (3–10), without using any biological component at room temperature and were found to be monohydrate form of monosodium urate.     

A Real-Time Digital Signal Analyzer Correlator Averager Power Spectral Density Analyzer

The digital signal analyzer described here computes the values of auto-and cross-correlation functions, recovers signals buried in noise, and computes cross-and auto-power spectral density at 100 equally spaced points on the time-delay axis or frequency axis. The results are presented on an oscilloscope or on an X-Y recorder.     

Optimal control of a boiling water nuclear reactor

Application of optimal control to a boiling water nuclear reactor is the theme of this paper. The optimal control problem of a linearized model of a reactor is treated as a regulator problem and feedback control laws are derived to drive the system to steady state in the presence of disturbances. The weighting matrices in the performance index of the regulator problem are suitably changed to yield acceptable closed-loop responses for specific disturbances. The disturbances considered are (i) impulse change in temperature of water at inlet to plenum chamber and (ii) step change in throttle valve area. Then the feedback control laws are implemented on the nonlinear model to illustrate their effectiveness both for large and small disturbances.     

Relaxation of operational amplifier parameters after pulsed electron beam irradiation

The relaxation of operational amplifier parameters (offset voltage and differential gain) with time after pulsed electron beam irradiation has been studied as a function of total dose and amplifier type. Four types of operational amplifiers were studied viz., general purpose bipolar input (μA 741), super-beta transistor input (LM 308), JFET input (LF 356) and MOSFET input (CA 3140) from different vendors. The experiments were carried out mainly using 500 ns pulses from a Linear Accelerator. The study, the first of its kind, shows that while the electrical transient at the output of the operational amplifier recovers in a few milliseconds, relaxation of parameters can take several to several tens of seconds. This relaxation is attributed to the build up and/or anneal of damage in the oxide or at the interface of the internal transistor structures. The change and relaxation of parameters depend on operational amplifier type and total dose, and can have significant effects in certain application domains as illustrated by the response of a thermocouple amplifier after pulsed irradiation.     

Self-assembled right handed helical ribbons of the bone mineral hydroxyapatite

A self-assembled right handed helical ribbon of bone mineral, hydroxyapatite (HAp) was crystallized in sodium meta silicate gel matrix at 27 degrees C and the physiological pH (7.4). At temperatures 37 and 47 degrees C, helical structures were followed by many Liesegang rings. The samples were characterized by FT-IR, XRD, SEM, ICP-OES and TG-DTA techniques. The helical ribbon consisted of platy Ca-deficient apatite crystals of size 2.8 microm. Liesegang ring had a continuous network of fibers with interconnected pores. The samples exhibited bioactivity when soaked in SBF.     

Hydrothermal synthesis of porous triphasic hydroxyapatite/(alpha and beta) tricalcium phosphate

A novel, porous triphasic calcium phosphate composed of nonresorbable hydroxyapatite (HAp) and resorbable tricalcium phosphate (alpha- and beta-TCP) has been synthesized hydrothermally at a relatively low temperature. The calcium phosphate precursor for hydrothermal treatment was prepared by gel method in the presence of ascorbic acid. XRD, FT-IR, Raman analyses confirmed the presence of HAp/TCP. The surface area and average pore size of the samples were found to be 28 m2/g and 20 nm, respectively. The samples were found to be bioactive in simulated body fluid (SBF).