Search

Hall effect measurements have been conducted on high-quality single crystals of the heavy-fermion superconductor CeCoIn5. The anomalous Hall contribution is negligible in the investigated temperature range from 0.05 to 5 K. The measured Hall resistivities ρxy show a noticeable change in slope between the low-field (initial Hall coefficient) and the high-field region. In the superconducting regime, T < 2.3 K, Hall measurements are restricted to high magnetic fields H > Hc 2, the upper critical field of superconductivity. The high-field Hall coefficient is almost constant for temperatures down to 250 mK. At T {less-than or slanted equal to} 250 mK, an additional change in curvature of ρxy vs. H is observed. © 2006 Elsevier B.V. All rights reserved.

The roles of glucose oxidase-catalase on the lipid oxidative stability and emulsion stability of a model emulsified salad dressing are investigated. The results indicate that glucose oxidase-catalase acts as an antioxidant or pro-oxidant in the salad dressing when present at a concentration lower or higher than 0.3 unit/g salad dressing respectively and also indicate that glucose odxidase-catalase is an emulsifying agents in the salad dressing.

Several Fe nanostructures with different lengths, diameters, and separations of the constituting magnetic components have been synthesized using anodized alumina membranes (AAMs) to understand the influence of these parameters on their magnetic properties. Fe nanostructures with high crystallinity and (110) orientation were synthesized by electrodeposition at room temperature in regular AAMs and mild-hard AAM (Mi-Ha AAM). Fe nanostructures with different aspect ratios (1:1, 1:10, and 1:75) in the form of nanodots, nanorods, or nanowires were synthesized in regular AAMs with the 100 nm interpore distance. Mi-Ha AAMs with two different pore sizes (70 and 120 nm) and 250 nm interpore distances were used to investigate the effect of the interactions and of the diameter of the wires on their magnetic behavior. Nearly linear magnetization characteristics with small coercivity, observed for Fe nanowires, suggest the magnetization rotation to be the predominant magnetization process for the field applied transverse to the wires. The anisotropy of the arrays was governed by the shape anisotropy of the magnetic objects with different aspect ratios. Reduced interactions between the nanowires grown in Mi-Ha AAMs resulted in enhancement of the average anisotropy. It is believed that due to difference in spin configuration, the increased diameter of the nanowires led to reduction in the coercivity in the case of the field applied along the wires. [ABSTRACT FROM AUTHOR]

α-Tocopherol was oxidized in methanol containing methylene blue for 30 h under light. The effects of 0, 250, 500, 1000, and 1500 ppm of oxidized α-tocopherol on the oxidative stability of purified soybean oil in the dark at 55 °C were studied by measuring the peroxide values and headspace oxygen contents in sample bottles. As the concentrations of oxidized α-tocopherol increased, the peroxide values increased and the headspace oxygen contents decreased during the 6 d of storage. The oxidized α-tocopherol compounds acted as prooxidant on the peroxide values and headspace oxygen contents of purified soybean oil. Tukey's test showed that oxidized α-tocopherol had a significant effect on the peroxide value and headspace oxygen disappearance of oil at P < 0.05. The prooxidant mechanisms of oxidized α-tocopherol may be due to α-tocopherol peroxy radical, α-tocopherol oxy radical, hydroxy radical, and singlet oxygen formed from the α-tocopherol. The oxidized α-tocopherol containing polar and nonpolar groups in the same molecule may reduce the surface tension of oil to increase the transfer of headspace oxygen to oil and accelerate the oil oxidation. [ABSTRACT FROM AUTHOR]

We examined the relationship between dietary intake and cognitive performance in Korean elderly people. Data for dietary intake, anthropometric measurements and cognitive function tests were collected and the relationships of the variables were analyzed. A random sample of 210 men and 239 women in Korea, aged 60 and over, was selected. Subjects were free-living elderly people who had not experienced major cognitive function impairment. Main outcome measures, 24 h dietary recall method, food behaviour variables, anthropometrics indices, health variables, and Kwon's Mini-Mental State Examination for Koreans (MMSE-K) for cognitive function test. The prevalence rate of poor cognitive function (MMSE-K score ≤19) of Korean elderly was 22.3%: women with poor cognitive function had a higher rate (31.0%) than that in men (12.3%). Cognitive ability was related negatively with age and positively with school education level. Female subjects of poor cognitive function had significantly lower intakes of total amount of foods, cereals, vegetables, fruits, milk, spices, and also, energy, protein, fat, carbohydrate, Ca, P, Fe, vitamin A, thiamin, riboflavin, and niacin than those of the normal cognitive score (≥24) group (P<0.05). Male subjects of poor cognitive function had significantly lower intakes of fruits, fiber, and vitamin C than the normal subjects (P<0.05). The MMSE-K score of female subjects showed a significant positive correlation with total amount of foods, cereals, beans, fruits, milk, oil, spices, and energy, protein, fat, carbohydrate, Ca, Fe, P, riboflavin and niacin intakes. The consumption of adequate nutrients, by taking sufficient amounts and variety of foods, may be important in maintaining adequate cognitive function in elderly Koreans.Public Health (2001) 115, 133–138. [ABSTRACT FROM AUTHOR]

In the present study, the effects of vitamins E and C on the levels of neurotransmitters and acetylcholinesterase activity in the brains of rats treated with scopolamine, an inducer of dementia, were examined. Fifty male Sprague-Dawley rats at the age of 5 wk were divided into five groups after 1 wk of adaptation and fed five different diets for 6 wk: a no-scopolamine group, which was a scopolamine-untreated group fed only a basal diet: a scopolamine-treated group fed a basal diet; a vitamin E-supplemented scopolamine-treated group: a vitamin C-supplemented scopolamine-treated group; and a vitamins E and C-supplemented scopolamine-treated group. Scopolamine was twice administered by intraperitoneal injection (300 mg/kg, body weight), 3 d and 20 min prior to sacrifice. Brain acetylcholinesterase activity was markedly reduced by scopolamine injection. However, the supplementation of vitamins E and C in the diet significantly increased the reduced brain acetylcholinesterase activity up to the level of the scopolamine-untreated group. Brain serotonin concentration in the vitamin C-supplemented scopolamine-treated group was significantly higher than that in the scopolamine-treated group. However, there were no significant differences in brain dopamine and norepinephrine concentrations among all groups. In conclusion, supplementation with vitamin E and/or vitamin C might be useful in maintaining brain acetylcholinesterase activity at the normal level and serotonin concentration for some extent under the condition to induce dementia by scopolamine administration.

The purpose of this study is to examine the toxicity of Alexandrium tamarense strains using a channel biosensor. With this biosensor, we were able to measure very small quantities of PSP toxin contained within an individual plankton cell. However, measurement of at least 100 cells is more desirable for increasing the sensitivity of the assay. Therefore, in the near future, the proposed biosensor system may be used for monitoring the STX (saxitoxin) produced by a few naturally toxic phytoplankton, and also measuring small amounts of toxin in shellfish.

To clarify the role of tumor necrosis factor (TNF) in the inflammatory aspects of autoimmunity vs its potential role in the apoptotic elimination of autoreactive effector cells, we assessed the roles of the p55 (TNFR1/Tnfrsf1a/CD120a) and p75 (TNFR2/Tnfrsf1b/CD120b) TNF receptors in the pathogenesis of MOG(35-55)-induced experimental autoimmune encephalomyelitis (EAE). TNFR p55/p75(-/-) double knockout mice were completely resistant to clinical disease. TNFR p55(-/-) single knockout mice were also totally resistant to EAE, exhibiting reduced MOG(35-55)- specific proliferative responses and Th1 cytokine production, despite displaying equivalent DTH responses. Importantly, IL-5 was significantly increased in p55(-/-) mice. In contrast, p75(-/-) knockout mice exhibited exacerbated EAE, enhanced Th1 cytokine production, and enhanced CD4(+) and F4/80(+) CNS infiltration. Thus, p55/TNFR1 is required for the initiation of pathologic disease, whereas p75/TNFR2 may be important in regulating the immune response. These results have important implications for therapies targeting p55 and p75 receptors for treating autoimmune diseases., (Copyright 2000 Academic Press.)

Background & Aims: Previous data suggest that oral antigen induces interferon (IFN)-gamma production in intestinal T cells. However, oral tolerance is associated with decreased production of IFN-gamma by T cells after antigen sensitization. The aim of this study was to examine the role of IFN-gamma in oral tolerance., Methods: Oral tolerance was examined in BALB/c mice after the adoptive transfer of T cells from chicken ovalbumin (OVA(323-339))-specific, DO11.10 x RAG-1(-/-) T-cell receptor transgenic mice., Results: OVA feeding induced systemic tolerance of delayed-type hypersensitivity (DTH) and antibody responses. OVA feeding up-regulated IFN-gamma production by transgenic T cells in Peyer's patch and mesenteric lymph node but not splenic tissues. Treatment of OVA-fed mice with neutralizing monoclonal antibody to IFN-gamma prevented tolerance of DTH responses. Analysis of transgenic T-cell numbers in DTH sites by immunohistochemical staining suggested that induction of IFN-gamma by oral antigen decreased accumulation of transgenic T cells in cutaneous sites of antigen injection. IFN-gamma-deficient or wild-type DO11.10 and BALB/c mice were used to show that IFN-gamma production by donor transgenic T cells was critical for oral tolerance., Conclusions: These data suggest that the induction of IFN-gamma by oral antigen contributes to systemic tolerance by decreasing migration of T cells to peripheral sites of inflammation.

Growing evidence suggests that advance directives (ADs) are often ineffective. Further explanation of how these documents are viewed by the public, the expectations of how decisions about treatment are made, and, in particular, patients' understanding of how ADs are actually used in the clinical setting, are warranted. This article details a descriptive study in which patients were interviewed, during hospital stays, about their beliefs and understanding of advanced directives, as well as the processes used in completing them. The study was undertaken in a community hospital located in a rural area in the Midwest. Findings show that many patients were able to clearly articulate what an AD means in terms of making their choices known. However, misconceptions were found in patients' understanding of ADs and only 46% reported discussing their ADs with a physician. Strategies for effective implementation of education programs related to ADs are detailed here.

Conidiation in Aspergillus nidulans is induced by exposure to red light but can also be induced by blue light in certain mutant strains. We have isolated a mutation in the fluG gene that abolishes responsiveness to red light but does not affect the response to blue light. It has been shown that the veA1 (velvet) mutation allows conidiation to occur in the absence of light. We have identified three other fluG mutations that suppress the veA1 phenotype; these double mutants do not conidiate in the dark. The mutations described here define two new phenotypic classes of fluG alleles that display abnormal responses to light. We have characterized these mutations with respect to their molecular identity and to their effect on fluG transcription. Although it has been shown that fluG is required for the synthesis of an extracellular factor that directs conidiation, we do not detect this factor under conditions that promote conidiation in the veA1 suppressors. Furthermore, extracellular rescue is not observed in fluG deletion strains containing the wild-type veA allele. We propose that a genetic interaction between fluG and veA influences the production of the extracellular signal and regulates the initiation of conidiation.

The effects of minor compounds on the oxidative stability of soybean oil were studied by measuring the contents of peroxides, headspace oxygen and volatile compounds. The effects of processing on minor component contents were also studied. Fatty acids, mono- and diacylglycerols, thermal or oxidized triacylglycerols, oxidized tocopherols and peroxides acted as prooxidant in soybean oil during storage at 55 degrees C. The phospholipids acted as prooxidant or antioxidant depending on the presence or absence of metals in the oil. The tocopherols acted as prooxidant or antioxidant depending on their concentration in the oil. The chlorophyll acted as a sensitizer to generate singlet oxygen in the photooxidation of soybean oils.

To gain further insight into how estrogens modulate cell function, the effects of estrogen on cell proliferation were studied in human breast cancer cells. We examined the effects of estrogen on the proliferation of three human breast cancer cell lines that differed in their estrogen receptor contents. Ten nM estradiol markedly stimulated the proliferation of MCF-7 human breast cancer cells that contained high levels of estrogen receptor (1.15+/-0.03 pmole/mg protein) over that of control. In T47D cells that contained low levels of estrogen receptor (0.23+/-0.05 pmole/mg protein), Ten nM estrogen slightly stimulated the proliferation over that of control. MDA-MB-231 cells, that contained no detectable levels of estrogen receptors, had their growth unaffected by estrogen. These results showed their sensitivity to growth stimulation by estrogen correlated well with their estrogen receptor content. Also we examined the effect of estrogen on cellular progesterone receptor level as well as plasminogen activator activity in MCF-7 cells. Ten nM estradiol showed maximal stimulation of progesterone receptor level as well as plasminogen activator activity in MCF-7 cells. It is not clear whether these stimulations of progesterone receptor and plasminogen activator activity by estrogen are related to the estrogen stimulation of cell proliferation of MCF-7 cells. Studies with estrogen in human breast cancer cells in culture indicate that sensitivity to growth stimulation by estrogen correlates well with estrogen receptor contents.

To gain further insight into how antiestrogens modulate cell function, the effects of antiestrogen on cell proliferation were studied in human breast cancer cells. We examined the effects of trans-tamoxifen on the proliferation of three human breast cancer cell lines that differed in their estrogen receptor contents. Trans-tamoxifen (1 muM) markedly inhibited the estrogen stimulated proliferation of MCF-7 human breast cancer cells that contained high levels of estrogen receptor (1.15+/-0.03 pmole/mg protein) over that of control. In T47D cells that contained low levels of estrogen receptor (0.23+/-0.05 pmole/mg protein), trans-tamoxifen (1 muM) showed minimal inhibition of estrogen stimulated cell proliferation over that of control. MDA-MB-231 cells, that contained no detectable levels of estrogen receptors, had their growth unaffected by trans-tamoxifen treatment. These results showed their sensitivity to growth inhibition by antiestrogen correlated well with their estrogen receptor content. Also we activator activity in MCF-7 cells. Trans-tamoxifen (1 muM) showed maximal inhibition of estrogen stimulated progestrone receptor level as well as plasminogen activator activity in MCF-7 cells that were stimulated by estrogen. It is not clear whether these inhibitions of progestrone receptor and plasminogen activator activity by estrogen are related to the antiestrogen inhibition of cell proliferation of MCF-7 cells. From the results of this study, it is clearly demonstrated that trans-tamoxifen is an antiestrogen in MCF-7 human breast cancer cells. Our data suggest that the biological effectiveness of trans-tamoxifen appear to result from its affinity of interaction with the estrogen receptor.

This two-part series describes the collaborative summer home care nursing program for Korean nurses conducted by the Frances Payne Bolton School of Nursing, Case Western Reserve University, Cleveland, OH, in cooperation with the College of Nursing of Yonsei University, Seoul, Korea. Part I focuses on the development of the collaboration, and part II focuses on the content of the three-week summer home care program and describes related issues and problems as well as suggests solutions. The series concludes with the findings on the program from the postprogram evaluations of students, preceptors, and patients. The collaborative educational program was developed to give Korean home care nurses an opportunity to gain clinical experience in home care nursing in the United States so that they could learn how to deliver better-quality home care for patients and their informal caregivers. Therefore, the program focused on practice-oriented lectures and clinical experiences.

Background: Despite the fact that the effectiveness of thrombolytic therapy for acute myocardial infarction is inversely related to the time between the onset of signs and symptoms and definitive therapy, long delays in seeking treatment have been reported consistently. A variety of reasons for the delays have been suggested. Because such delays are associated with longer hospital stays and higher mortality and morbidity, interventions that reduce delays are especially important., Purpose: To examine research on patients with myocardial infarction who delay seeking professional treatment and the factors related to the delay, and to review studies indicating that black patients have premonitory clinical signs and symptoms of myocardial infarction and changes in the structure and function of the cardiovascular system that are different from those in whites., Methods: Studies were reviewed by using MEDLINE and by doing a manual search of relevant research journals in cardiovascular, nursing, and behavioral medicine published since 1970. Data published by the United States Department of Health and Human Services and the Agency for Health Care Policy and Research were also reviewed., Results: Although the lengths of the delays have varied considerably, blacks have generally experienced longer delays than whites between acute onset of signs and symptoms of myocardial infarction and arrival at the emergency department. Studies show that black patients have a lower incidence of classic chest pain or discomfort but an increased incidence of dyspnea, whereas white patients are much more likely to complain of chest pain., Conclusion: Culturally sensitive public education about typical and atypical premonitory clinical signs and symptoms of myocardial infarction and the significance of early treatment of myocardial infarction in blacks is needed.

This study was attempted to provide us with basic information on how to improve understanding with patients for operation, and to offer them better nursing and treatment. This kind of study will help scientific application to nursing practice and operating room. The data was collected by interviewing 29 patients who underwent the elective surgery under the general anesthesia at Y hospital in Seoul. The interview ran from October 15 to December 15, 1989. The research instrument was a anxiety measurement device (SAAI) originally developed by Spielberger, et al and modified by Jung-Tack Kim. 1. Hypothesis Testing Hypothesis one was that there would be a difference in state anxiety level according to a time difference in waiting for operation. This hypothesis was rejected (state anxiety level one hour before operation P greater than .05, r = .747, State anxiety level half an hour before operation P greater than .05, r = .1550, state anxiety level just before operation, P greater than .05, r = .1099). However, state anxiety level appeared to be associated with a longer waiting period, like one day before operation (P less than .05, r = .4628). Hypothesis two was that there would be a difference according to state anxiety level of patients for operation. This was rejected. (Change of blood pressure in systolic P greater than .05, r = -.1082. Change of blood pressure in diastolic P greater than .05, r = -.088, Change of pulse rate, P less than .05, r = 1.909) 2. Examining trait anxiety and state anxiety levels, the average level of trait anxiety was 42.034, and the average level of state anxiety one day before operation was 43,000. The average level of state anxiety was averaged 42.356 in a waiting room for operation. 3. Examining the state anxiety level by time period, the level one hour before was 42.379, the level half an hour before 42.276, and the level just before operation 42.414. The low level of state anxiety was due to the fact that premedication was not eliminated. 4. Age and time period like one day before operation was related to state anxiety level (F = 5.271, P less than .001) and blood pressure in waiting room for operation. That is, state anxiety level and blood pressure of patients one day before operation appeared high. Sex was related to changes of blood pressure; the blood pressure of male patients appeared higher than that of female patients.(ABSTRACT TRUNCATED AT 400 WORDS)