Magnetoresistively detected electron spin resonance in low-density two-dimensional electron gas in GaAs-AlGaAs single quantum wells

Electron spin resonance (ESR) is a natural candidate for quantum bit manipulation, provided that the confinement of a small number of electrons in a sufficiently small volume can be achieved. An important step is the development of low carrier density materials and structures in which the electron spins are isolated and can be controlled by ESR. We report on the realization of three low-density (n/sub 1/=1.77/spl times/10/sup 10/, n/sub 2/=4.5/spl times/10/sup 10/, and n/sub 3/=9/spl times/10/sup 10/ cm/sup -2/ without the help of a gate to deplete the channel) two-dimensional electron systems in GaAs-AlGaAs single quantum wells (QWs) and on the magnetoresistively detected electron spin resonance (MDESR) measurements in these samples. The MDESR has been characterized at /spl nu/=1 and /spl nu/=3 and the current intensity, microwave power, and temperature dependence have been studied. The structures that have been investigated represent the lowest density single QW samples in which MDESR has been detected. The implications of detection of the MDESR at such low electron density to coupled quantum-dot spin device technology will be presented.     

Oral ondansetron for the control of cisplatin-induced delayed emesis: a large, multicenter, double-blind, randomized comparative trial of ondansetron versus placebo

PURPOSE: To investigate the efficacy and safety of oral ondansetron in the control of cisplatin-induced delayed emesis in patients who do not require rescue antiemetic therapy for acute emesis. PATIENTS AND METHODS: Five hundred thirty-eight chemotherapy-naive patients who received cisplatin chemotherapy (> or = 70 mg/m2), and who were not rescued for acute emesis, were eligible to be randomized to receive one of the three oral regimens to control delayed emesis. Group I received placebo on days 2 to 6; group II received ondansetron 8 mg twice daily on days 2 and 3 and placebo on days 4 to 6; group III received ondansetron 8 mg twice daily on days 2 to 6. All patients received intravenous ondansetron (0.15 mg/kg every 4 hours for three doses) for the control of acute emesis on day 1. The number of emetic episodes on days 2 and 3 combined (days 2/3, when incidence and severity of delayed emesis were expected to be greatest) was considered the primary measure of efficacy. RESULTS: Patients who received odansetron had significantly fewer emetic episodes on days 2/3, 4, and 5 than those who received placebo (P < or = .002 on each day). Additionally, significantly more patients who received ondansetron had a complete plus major response (C+MR; < or = two two emetic episodes) than those who received placebo on days 2/3 (56% v 37%, P = .001), 4 (94% v 85%, P = .005), and 5 (98% v 88%, P = .006). Patients who received ondansetron had significantly less nausea on day 2/3 when day-1 nausea was used as the baseline score (P = .025). Patients who received ondansetron also had significantly less nausea on day 4 (P = .042) and the results approached significance on day 5 (P = .066). CONCLUSION: Oral ondansetron had a significant effect in the control of cisplatin-induced delayed emesis and nausea in patients who had not required rescue antiemetics during the acute emesis period. The control of delayed nausea and vomiting was most notable in the immediate 2 days following cisplatin administration, with the clinical difference narrowing between the two treatment arms on subsequent days.     

Cinnamyl anthranilate causes coinduction of hepatic microsomal and peroxisomal enzymes in mouse but not rat

Cinnamyl anthranilate is a synthetic food flavoring and fragrance agent, formerly used at low levels. Although it is not genotoxic, very high doses have been shown to cause liver tumors in mice but not rats. In this report we characterize hepatic changes brought about by cinnamyl anthranilate in rats and mice. Groups of male CD1 mice and Fischer 344 rats received 0, 100, or 1000 mg/kg cinnamyl anthranilate by intraperitoneal injection daily for 3 days. After euthanization on the 4th day, plasma lipids and relative liver weight, tissue DNA, the peroxisome marker CN(-)-insensitive palmitoyl-CoA oxidation, cytochrome P450, microsomal lauric acid hydroxylation, aminopyrine N-demethylase and ethoxyresorufin O-deethylase, bilirubin UDP-glucuronosyltransferase, microsomal and cytosolic epoxide hydrolase, and the peroxisome/mitochondria ratio in liver sections were monitored. In mice a pattern of change pointing to peroxisomal proliferation was seen at both doses of cinnamyl anthranilate, but in rats fewer and smaller changes were seen with little or no evidence of peroxisomal proliferation at the doses used. Groups of male CD1 mice were given 0-200 mg/kg cinnamyl anthranilate daily for 3 days. At doses of 20 mg/kg and above, there were dose-dependent increases in relative liver weight, total cytochrome P450, and CN(-)-insensitive palmitoyl-CoA oxidation. The hepatic effects of cinnamyl anthranilate are apparently due to the intact ester, since neither its expected metabolites alone nor an equimolar mixture of the hydrolysis products, cinnamyl alcohol and anthranilic acid, had any significant effect on the weight or marker enzyme content of mouse liver. The data are discussed in relation to the species specificity of the hepatocarcinogenicity of cinnamyl anthranilate and to metabolic studies in rats and mice. It is suggested that in mice, peroxisomal proliferation occurs only at doses high enough to prevent complete metabolic hydrolysis.     

Interfering with somatosensory stimulation from pups sensitizes experienced, postpartum rat mothers to oxytocin antagonist inhibition of maternal behavior.

Proximal separation (PS) refers to isolating pups in small cages so dams can hear, smell, and see pups but have very limited physical contact with them. Six days of PS diminished the number of discernible oxytocin (OT)- immunostaining perikarya in forebrain areas of rat dams compared with 6 days of total separation (TS) or no separation (NS) from pups. Dams exhibited a more rapid resurgence of maternal behavior after 4–6 days of PS than after 4–6 days of TS. Bilateral infusion of the OT antagonist (OTA; 1 μg/μl/side) into the ventral tegmental area blocked the resurgence of maternal behavior after 3–6 days of PS but not after 2 days of PS or 4–6 days of NS. The conclusion was that PS for 3 or more days reinstates OT as necessary and sufficient for the activation of maternal behavior in experienced rat mothers. These findings suggest that some aspects of somatosensory stimulation from pups regulate the role of OT in the control of maternal behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The determination of active filter aid adsorption sites by temperature-programmed desorption

Temperature programmed desorption (TPD) was used to evaluate the active sites of several filter aids that have been promoted for use by the deep-frying industry: activated carbon, aluminas, bleaching earths, diatomaceous earth, silica and synthetic magnesium silicate. TPD analysis determines both the total surface concentration of the active sites and the details of their intensity distribution. A correlation analysis was made between the adsorbents' oil treatment performance and the observed acidic/basic sites. For some of the adsorbents, the adsorption of free fatty acids and the percent change in the color of the oil was shown to relate to the total basic sites and acid sites, respectively. The study also showed that other factors might affect these adsorptivities.     

Contact pressure in rolled tube-tubesheet joints

The residual contact pressure in a rolled tube-tubesheet joint is calculated for several practical tube-tubesheet size and material selections. The analysis follows the elastic-plastic strain history during the tube expansion process. It accounts also for the initial gap size, reversed yielding, and material strain-hardening of both the tube and the tubesheet. The residual contact pressure is expressed as a function of the degree of expansion of the tube. The inside diameter of the tube after rolling (apparent wall reduction) is chosen as the measure of the expansion. Plots of the residual contact pressure versus the apparent wall reduction show that in all cases the contact pressure attains most of its value within 3–6% of the apparent wall reduction. Further rolling is of no benefit to the residual contact pressure.     

cis-Diaminedichloroplatinum(II) complexes reversibly bound to water-soluble polyaspartamide carriers for chemotherapeutic applications. II: Platinum coordination to ethylenediamine ligands attached to poly(ethylene oxide)-grafted carrier polymers

In continuation of previous investigations aiming at the development of macromolecular metal complexes for biomedical use, this communication describes poly(alkylene oxide)-grafted polymeric platinum complexes. The platinum-containing macromolecules are obtained from presynthesized polyaspartamide carriers bearing poly(ethylene/propylene oxide) side chains and hydroxyethyl side groups as hydrosolubilizing units in addition to ethylenediamine side group terminals for metal coordination. Platination is brought about by treatment of the carriers with tetrachloroplatinate(II) ion in aqueous solution at 25–60°C. pH 4–6. The polymeric products, purified by dialysis in aqueous solution, are isolated by freeze-drying in yields of 60–80%. Platinum contents are in the range of 4–15%. The metal is bound to the carrier through chelation with the ethylenediamine ligands, forming square-planarcis-dichloroethylenediamine-platinum(II) complex species as side-chain terminals. Initially, the product polymers dissolve smoothly in water. Although on room-temperature storage in the solid state they gradually turn insoluble as a consequence of intermolecular solid-state interaction, solubility is retained on low-temperature storage and in frozen aqueous solutions.     

A descriptive analysis of the Journal of Manipulative and Physiological Therapeutics, 1989-1996

BACKGROUND: Two previous reports have summarized the content, institutional affiliations, academic training and funding sources for articles published in the Journal of Manipulative and Physiological Therapeutics (JMPT) from 1978-1986 and 1987-1988. OBJECTIVES: (a) to quantitatively assess the types of articles published in the JMPT from 1989-1996; (b) to identify the affiliations of contributors to the JMPT during this period; (c) to identify the academic backgrounds of contributors to the JMPT from 1989-1996; (d) to identify funding sources for scholarly works published in the JMPT during this period; (e) to identify the proportionate contributions of female authors; (f) to assess the proportion of articles contributed, i.e., foreign vs. domestic sources; and (g) to compare findings for the JMPT from 1989-1996 with similar data for 1978-1988. STUDY DESIGN: Survey of the contents of the JMPT from 1989-1996. METHODS: The contents of the 69 issues of the JMPT from 1989-1996 were reviewed by all authors. Characteristics extracted included category of the article, academic backgrounds of authors, institutional affiliations of authors, funding sources, gender of authors and nation(s) of origin of articles. RESULTS: The annual rate of published contributions to the Journal has more than doubled compared with its first 11 yr of publication, and the proportion of original data reports has grown slightly. Controlled and quasicontrolled clinical trials were 7 times more numerous (n = 28 articles) during the past 8 yr. Chiropractic colleges were the most frequently mentioned affiliation of authors, followed by private practice and nonchiropractic colleges. Collaborative articles submitted by authors at two or more chiropractic colleges grew from only 4 articles from 1978-1988 to 31 articles from 1989-1996. As in previous years, the National College of Chiropractic continued to be the most frequently mentioned academic affiliation of authors. The numbers of articles contributed by those holding scientific (e.g., PhD) and medical degrees have grown substantially. The number of articles mentioning financial support grew from 78 from 1978-1988 to 179 from 1989-1996, and 58 new funding sources were identified. The Foundation for Chiropractic Education and Research continues to be the most frequently mentioned source of funding. Of all articles published in the JMPT from 1989-1996, 21% were authored or coauthored by women. Of 1050 articles, 286 (27%) were authored or coauthored by individuals residing outside the United States of America. CONCLUSIONS: Substantial increases in scholarly activities within the chiropractic profession are suggested by the growth in scholarly products published in the discipline's most distinguished periodical. Increases in controlled outcome studies, collaboration among chiropractic institutions, contributions from nonchiropractors, contributions from nonchiropractic institutions and funding for research suggest a degree of professional maturation and growing interest in the content of the discipline.