Gyrotron Backward Wave Oscillator Experiments with a Relativistic Electron Beam Using an X-Band Rectangular Waveguide

A mildly relativistic electron beam (500keV, 200A, 10ns) injected into an X-band rectangular waveguide immersed in a uniform axial magnetic field (4-10kG) produced magnetically tunable microwave radiation in the 9-13 GHz frequency range with an estimated output power of 1MW. The frequency range and tunability of the radiated microwave agreed with a theoretical model for a gyrotron backward wave oscillator taking into account the low energy component of the beam electron.     

Mechanism for the anomalous degradation of Si solar cells induced by high-energy proton irradiation

High-energy and high-fluence proton irradiation of Si space solar cells has provoked an anomalous increase in short-circuit current, followed by its abrupt decrease and cell failure. A model is proposed which explains the phenomena by expressing a reduction in the carrier concentration of the base region, in addition to a decrease of minority-carrier diffusion length. The reduction in carrier concentration due to majority-carrier trapping by radiation-induced defects has the effect of (1) broadening the depletion region width and (2) increasing the resistivity of the base layer. The anomalous change in the quantum efficiency of the cells under high-fluence ( 10¹⁴cm⁻²) irradiation is also explained by considering the generation of a donor-type defect level with the irradiation.     

p300 and ATF-2 are components of the DRF complex, which regulates retinoic acid- and E1A-mediated transcription of the c-jun gene in F9 cells

The effects of transferring clients from assertive community treatment to a less intensive (step-down) case management program were examined. Service use decreased significantly after transfer to the step-down program, and no negative effects of transfer on hospital use or client functioning were evident. Critical elements for successful step-down are suggested and discussed.     

Inhibition of apoptosis by survivin predicts shorter survival rates in colorectal cancer

Deregulated inhibition of apoptosis (programmed cell death) may facilitate the insurgence of neoplasia, but whether it also influences the outcome of common cancers has remained controversial. In this study, we investigated the expression of a novel inhibitor of apoptosis, survivin, in colorectal cancer and its relationship with tumor cell apoptosis and overall prognosis. By immunohistochemistry, survivin was expressed in 91 of 171 (53.2%) cases of colorectal carcinomas of histological stages 0 to IV. In contrast, normal colon epithelium did not express survivin. Although survivin expression did not correlate with p53 abnormalities (46.5% versus 58.0%; P = 0.18), survivin-positive cases were strongly associated with bcl-2 expression (72.5% versus 27.4%; P < 0.0001) and reduced apoptotic index (0.76% +/- 0.39% versus 1.17% +/- 0.62%; P < 0.0001). Expression of survivin alone in bcl-2-negative (discordant) cases also resulted in reduced apoptotic index (0.82% +/- 0.57% versus 1.16% +/- 0.66%; P = 0.0046). When analyzed for prognostic significance, patients with low apoptotic index (< 0.97%) had worse survival rates than the group with high apoptosis (P < 0.001), and a multivariate Cox proportional hazard model identified reduced apoptosis as an independent predictive factor for overall survival (P < 0.0001). These data demonstrate that apoptosis inhibition by survivin, alone or in cooperation with bcl-2, is an important predictive/prognostic parameter of poor outcome in colorectal carcinoma and identify survivin as a new diagnostic/therapeutic target in cancer.     

Erythromycin modulates IL-8 expression in normal and inflamed human bronchial epithelial cells

Previous studies have shown that blood plasma levels of 17alpha, 20beta-dihydroxy-4-pregnen-3-one (DHP) and 17alpha, 20beta, 21-trihydroxy-4-pregnen-3-one (20beta-S) increase in striped bass (Morone saxatilis) undergoing final oocyte maturation (FOM). Both hormones are produced by ovarian fragments undergoing hCG-induced germinal vesicle breakdown (GVBD) in vitro. In the present study, we investigated binding of DHP and 20beta-S to ovarian membranes from striped bass undergoing FOM. Saturable binding sites for DHP were not detected. Saturation of 20beta-S binding sites with 5 nM [3H]20beta-S occurred within 40 min at 0 degrees C (at 3 min, half of the maximum specific binding of steroid was calculated to have occurred), and the binding was pH-dependent. Scatchard analyses revealed the presence of a single class of high-affinity (dissociation constant [Kd] = 1.4 +/- 0.2 nM), limited-capacity (estimated concentration [Bmax] = 2.7 +/- 0.3 pmol/g ovary) 20beta-S binding sites on membranes from striped bass ovaries undergoing FOM. In contrast, only low levels of specific binding (Bmax < 0.04 pmol/g tissue) were detected on membranes from testes, liver, brain, and muscle. Ovarian membranes prepared from vitellogenic females also had low levels (Bmax < 0.1 pmol/g ovary) of specific 20beta-S binding, less than 5% of that found during FOM. Results of competition assays showed that DHP was approximately 250 times less effective than 20beta-S for displacing 20beta-S from ovarian membranes. In contrast, 20beta, 21-dihydroxy-4-pregnen-3-one was a very effective competitor, although it is only a weak inducer of oocyte GVBD in vitro. Of several other steroids tested, only progesterone showed affinity for the 20beta-S binding site within a physiological range of concentrations. Taken together with previous studies of striped bass FOM, these findings indicate that 20beta-S is the oocyte maturation-inducing steroid hormone in striped bass.     

Effects of peritoneal insufflation on hepatic and renal blood flow

The effects of peritoneal insufflation with carbon dioxide on hepatic and renal blood flow have not been reported hitherto. We evaluated these effects in a porcine model of abdominal laparoscopic surgery. Seven anesthetized pigs underwent peritoneal insufflation in a step-wise manner to create intraabdominal pressures of 6, 12, 18 and 24 mmHg, and changes in the arterial and venous pressure, arterial blood gases, and hepatic and renal blood flow were monitored. Both the hepatic and renal blood flow decreased as the intraabdominal pressure increased. Therefore, in order to carry out laparoscopic abdominal surgery safely in patients with hepatic or renal impairment, low intraabdominal pressures or noninsufflating techniques are recommended.     

Amino acids and peptides. XXI. Laminin-related peptide analogs including poly(ethylene glycol) hybrids and their inhibitory effect on experimental metastasis

Laminin-related peptides, Tyr-Ile-Gly-Ser-Arg analogs, were prepared and their inhibitory effects on experimental metastasis were examined. Of the amino acids in the Tyr-Ile-Gly-Ser-Arg sequence, L-Arg was very important and Ile was not essential for the inhibitory effect. To obtain a potent inhibitor of metastasis, hybrids of Tyr-Ile-Gly-Ser-Arg-Gly and 2 types of poly(ethylene glycol) were prepared. The inhibitory effects of the hybrids were more potent than that of Tyr-Ile-Gly-Ser-Arg-Gly.     

Small class organization in individualized instruction

A new method for small class organization is presented. Learners of similar mastery levels are classified into predetermined groups based on the learner-states and group characteristics. The method is applicable to organization of supplementary lectures for individualized instruction or conventional classroom teaching.     

Automotive Noise from a Motorway: Part I, Measurement

This paper describes 100-MHz measurements of the amplitude-probability (APD) and crossing-rate distributions (CRD) for automotive-traffic radio noise at Toyokawa, Japan. Two different categories of the results of measurements for automotive-traffic radio noise are described: 1) one category is the aggregate of APD/CRD pairs measured for the noise samples of 15-min duration, each of which gives a statistically stationary datum, and 2) the other is the aggregate of APD/CRD pairs measured for the noise samples of 2-s duration, each of which gives a transient datum belonging to the components of a statistically stationary datum. A series of the noise grades for single-motor vehicles passing on a motorway is described in terms of APD/CRD pairs for the noise samples of 2-s duration.