Giant magnetoresistance for superparamagnetic particles: Melt-spun granular CuCo.
Explore the source record for details and available documents.
SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Molecules of the title compound (alternative name p-methoxybenzaldehyde 2-pyridylhydrazone), C(13)H(13)N(3)O, adopt an E configuration about the azomethine C=N double bond. Molecules are almost planar, the dihedral angle between the pyridine and methoxyphenyl rings being only 6.19 (12) degrees. Pairwise N-H.N hydrogen bonds [R(2)(2)(8) in graph-set notation] link centrosymmetrically related molecules into discrete pairs.
Molecules of the title compound (alternative name: p-nitrobenzaldehyde phenylhydrazone), C(13)H(11)N(3)O(2), adopt an E configuration about the azomethine C=N double bond. Molecules are approximately planar and the dihedral angle between the planes of the phenyl rings is 11.62 (9) degrees. Hydrogen bonding links molecules related by 4(2) screw axes to form helices with a pitch of 7.7186 (8) A.
The title compound, [Co(C11H10N3O)2]ClO4, designated [Co(L2)2]ClO4, was synthesized by reaction of Co(II) with two molar equivalents of (2-pyridyl)bis(2-pyridylamino)methane (L1) under ambient conditions, whereby the divalent metal ion was oxidized concomitantly with oxygenation and deamination of the aminal polydentate ligand to generate the tridentate ligand anion (2-pyridyl)(2-pyridylamino)methanolate, L2-. In the X-ray crystal structure of the complex cation, [Co(L2)2]+, the two L2- ligands are coordinated to the central cobalt(III) metal ion in a facial mode to afford a pseudo-octahedral geometry. The four pyridyl N atoms constitute the equatorial plane on which the cobalt(III) ion lies; the methanolate O atoms occupy the axial positions.
Previous studies on ventilatory control in obstructive sleep apnea (OSA) have generally indicated depressed chemosensitivity, implying greater stability of the chemical control of breathing in these subjects. However, these results were based on tests involving steady-state or quasi-steady measurements obtained in wakefulness. We have developed a method for assessing the dynamic stability characteristics of chemoreflex control in OSA patients during sleep. While continuous positive airway pressure was applied to stabilize the upper airways, acoustically stimulated arousals were used to perturb the respiratory system during sleep. The fluctuations in esophageal pressure that ensued were analyzed, using a closed-loop minimal model, to estimate the chemoreflex loop impulse response (CLIR). Tests using simulated data confirmed the validity of our estimation algorithm. Application of the method to arousal responses measured in six OSA and five normal subjects revealed no statistically significant differences in gain margins and loop gain magnitudes between the two groups. However, the CLIR in the OSA subjects exhibited faster and more oscillatory dynamics. This result implies that, in addition to unstable upper airway mechanics, an underdamped chemoreflex control system may be another important factor that promotes the occurrence of periodic obstructive apneas during sleep.
Accurate and computationally efficient means of classifying surface myoelectric signals has been the subject of considerable research effort in recent years. The aim of this paper is to classify myoelectric signals using new fuzzy clustering neural network (NN) architectures to control multifunction prostheses. This paper presents a comparative study of the classification accuracy of myoelectric signals using multilayered perceptron NN using back-propagation, conic section function NN, and new fuzzy clustering NNs (FCNNs). The myoelectric signals considered are used in classifying six upper-limb movements: elbow flexion, elbow extension, wrist pronation and wrist supination, grasp, and resting. The results suggest that FCNN can generalize better than other NN algorithms and help the user learn better and faster. This method has the potential of being very efficient in real-time applications.
Volterra series representation of nonlinear systems is a mathematical analysis tool that has been successfully applied in many areas of biological sciences, especially in the area of modeling of hemodynamic response. In this study, we explored the possibility of using discrete time Meixner basis functions (MBFs) in estimating Volterra kernels of nonlinear systems. The problem of estimation of Volterra kernels can be formulated as a multiple regression problem and solved using least squares estimation. By expanding system kernels with some suitable basis functions, it is possible to reduce the number of parameters to be estimated and obtain better kernel estimates. Thus far, Laguerre basis functions have been widely used in this framework. However, research in signal processing indicates that when the kernels have a slow initial onset or delay, Meixner functions, which can be made to have a slow start, are more suitable in terms of providing a more accurate approximation to the kernels. We, therefore, compared the performance of Meixner functions, in kernel estimation, to that of Laguerre functions in some test cases that we constructed and in a real experimental case where we studied photoreceptor responses of photoreceptor cells of adult fruitflies (Drosophila melanogaster). Our results indicate that when there is a slow initial onset or delay, MBF expansion provides better kernel estimates.
Sierra Leone suffered from 11 years of civil war (1991-2002) resulting in tens of thousands of deaths and mutilations together with massive population displacement. In 2001, ARC International, Sierra Leone conducted a baseline survey of 201 commercial sex workers (CSWs) and 202 military respondents on the knowledge, attitudes and practices surrounding HIV/AIDS and STIs in Port Loko, Sierra Leone. In 2003, a comparable post-intervention survey of 202 CSWs and 205 military respondents was performed. Comparison of baseline and post-intervention results showed that HIV/AIDS knowledge increased among both groups, with those able to name three effective means of avoiding AIDS increasing from 5 per cent to 70 per cent among CSWs, and 11 to 75 per cent among the military. Reported condom use during last sex increased among CSWs from 38 to 68 per cent and among military from 39 to 68 per cent. These results demonstrate that, despite the challenges inherent in a post-conflict country, good-quality AIDS-prevention programmes can be effective.
BACKGROUND: Ornamental Ficus benjamina (FB) has been recognized as a new indoor allergen. Little is known about the prevalence in moderately exposed subjects and the proposed association with fruit and Hevea latex hypersensitivity. OBJECTIVE: To study the prevalence of FB sensitization and the relationship with Hevea latex allergy, to identify cross-reacting fruits, and to characterize the responsible allergens. METHODS: A skin prick test solution prepared from FB latex (200 microg/mL) was included in our routine screening programme for suspect inhalant allergy. Patients reacting with the FB extract were further skin tested with exotic fruits by the prick-to-prick method. Inhibition of fig and FB CAP by FB latex, fig (Ficus carica), kiwi, the thiolproteases ficin and papain, Hevea latex and rHev b 6.02 (hevein) was performed in selected patients. RESULTS: Of 2662 patients with a positive skin test to any aeroallergen, 66 (2.5%) reacted with FB. Ten patients showed isolated sensitization to FB. Although FB-positive subjects were more often co-sensitized to Hevea latex than FB-negative (10.6% vs 3.8%, P< 0.01), nearly 90% tested negative for Hevea latex. Sensitization to FB was specifically associated with positive skin tests to fresh fig (83%), dried fig (37%), kiwi fruit (28%), papaya (22%), avocado (19%), banana (15%), and pineapple (10%) (n = 54). Clinical reactions were reported mainly from fresh and dried fig and kiwi (47%, 60%, and 64%, respectively, of skin test-positive patients), including seven patients with systemic reactions (urticaria, angiooedema, asthma). CAP to fig in 11 patients with clinical fruit allergy was inhibited on average by 87% by FB latex, 89% by fresh fig, 80% by dried fig, 38% by kiwi (100 microg/mL each), and by 59% and 44% by ficin and papain (50 microg/mL), respectively. No inhibition was obtained with Hevea latex and rHev b 6.02. CAP to FB was inhibited on average by 95% by FB, 60% by fresh fig, 41% by ficin, 29% by papain, and less than 7% by rubber latex allergens. CONCLUSIONS: Sensitization to FB latex is found in 2.5% of atopic individuals and mostly occurs independently of Hevea latex allergy. Sensitization is commonly associated with allergic reactions to figs and other tropical fruits ('Ficus-fruit syndrome'). This cross-reactivity is mediated at least in part by thiolproteases.
Healing/protective responses in human visceral leishmaniasis (VL) are associated with stimulation/production of Th1 cytokines, such as interferon IFN-gamma, and conversion in the leishmanin skin test (LST). Such responses were studied for 90 days in 44 adult healthy volunteers from VL non-endemic areas, with no past history of VL/cutaneous leishmaniasis (CL) and LST non-reactivity following injection with one of four doses of Alum-precipitated autoclaved Leishmania major (Alum/ALM) +/- bacille Calmette-Guerin (BCG), a VL candidate vaccine. The vaccine was well tolerated with minimal localized side-effects and without an increase in antileishmanial antibodies or interleukin (IL)-5. Five volunteers (5/44; 11.4%) had significant IFN-gamma production by peripheral blood mononuclear cells (PBMCs) in response to Leishmania antigens in their prevaccination samples (P = 0.001) but were LST non-reactive. On day 45, more than half the volunteers (26/44; 59.0%) had significantly high LST indurations (mean 9.2 +/- 2.7 mm) and high IFN-gamma levels (mean 1008 +/- 395; median 1247 pg/ml). Five volunteers had significant L. donovani antigen-induced IFN-gamma production (mean 873 +/- 290; median 902; P = 0.001), but were non-reactive in LST. An additional five volunteers (5/44; 11.4%) had low IFN-gamma levels (mean 110 +/- 124 pg/ml; median 80) and were non-reactive in LST (induration = 00 mm). The remaining eight volunteers had low IFN-gamma levels, but significant LST induration (mean 10 +/- 2.9 mm; median 11). By day 90 the majority of volunteers (27/44; 61.4%) had significant LST induration (mean 10.8 +/- 9.9 mm; P < 0.001), but low levels of L. donovani antigen-induced IFN-gamma (mean 66.0 +/- 62 pg/ml; P > 0.05). Eleven volunteers (11/44; 25%) had significantly high levels of IFN-gamma and LST induration, while five volunteers had low levels of IFN-gamma (<100 pg/ml) and no LST reactivity (00 mm). One volunteer was lost to follow-up. In conclusion, it is hypothesized that cellular immune responses to human VL are dichotomatous, and that IFN-gamma production and the LST response are not in a causal relationship. Following vaccination and probably cure of VL infection, the IFN-gamma response declines with time while the LST response persists. LST is a simple test that can be used to assess candidate vaccine efficacy.
AIM: Isolation and characterization of a bacterial isolate (strain FP10) from banana rhizosphere with innate potential as fungal antagonist and microbial adjuvant in micropropagation of banana. METHODS AND RESULTS: Bacterium FP10 was isolated from the banana rhizosphere and identified as Pseudomonas aeruginosa based on phenotypic, biochemical traits and sequence homology of partial 622-bp fragment of 16S ribosomal DNA (rDNA) amplicon, with the ribosomal database sequences. Strain FP10 displayed antibiosis towards fungi causing wilt and root necrosis diseases of banana. Production of plant growth hormone, indole-3-acetic acid (IAA), siderophores and phosphate-solubilizing enzyme in FP10 was determined. Strain FP10 tested negative for hydrogen cyanide, cellulase and pectinase, the deleterious traits for plant growth. Screening of antibiotic genes was carried out by polymerase chain reaction using gene-specific primers. Amplification of a 745-bp DNA fragment confirmed the presence of phlD, which is a key gene involved in the biosynthesis of 2,4-diacetylphloroglucinol (DAPG) in FP10. The antibiotic produced by FP10 was confirmed as DAPG using thin layer chromatography, high performance liquid chromatography and Fourier transform infrared and tested for fungal antibiosis towards banana pathogens. Procedures for encapsulation of banana shoot tips with FP10 are described. CONCLUSIONS: Strain FP10 exhibited broad-spectrum antibiosis towards banana fungi causing wilt and root necrosis. DAPG by FP10 induced bulb formation and lysis of fungal mycelia. Encapsulation of banana shoot tips with FP10 induced higher frequency of germination (plantlet development) than nontreated controls on Murashige and Skoog basal medium. Treatment of banana plants with FP10 enhanced plant height and reduced the vascular discolouration as a result of Fusarium oxysporum f. sp. cubense FOC. SIGNIFICANCE AND IMPACT OF THE STUDY: Because of the innate potential of fungal antibiosis by DAPG antibiotic and production of siderophore, plant-growth-promoting IAA and phosphatase, the strain FP10 can be used as biofertilizer as well as a biocontrol agent.
The ability of many organisms to switch to new hosts can be critical to their survival in the wild. However, the genetic mechanisms underlying such shifts are poorly understood. In this study, we used complementary DNA (cDNA) microarrays to ask if changes in gene expression are observed in response to a dietary shift in Drosophila melanogaster, a dietary generalist. We found significant and repeatable differential expression in a number of genes related to metabolic function and stress, suggesting that a functional genomics approach will be useful in seeking loci involved in the ability of flies to utilize different resources.
OBJECTIVES: To estimate the prevalence of obesity and overweight among adults in a high mountain rural population of Pakistan, and to determine the correlates of excess body weight. Design Cross-sectional study. METHODS: A random sample of 4203 adults (aged 18 years and over) was selected by stratified random sampling from 16 villages in north Pakistan. Trained medical students measured height, weight and blood pressure. Trained interviewers obtained information from participants on sociodemographic variables, use of snuff, daily cigarette consumption, hypertension and family history of hypertension. Body mass index (BMI) calculated as kg/m(2) was used to define overweight (BMI > or = 25 kg/m(2)) and obesity (BMI > or = 30 kg/m(2)). RESULTS: Using weight and height data available for 1391 men and 2754 women, mean BMI was 22.4 (95% CI 21.9, 22.9) for men and 22.6 (95% CI 21.9, 23.2) for women. The age-adjusted prevalence of BMI > or = 25 (overweight/obesity) was 13.5% for men and 14.1% for women. Overweight/obesity increased with age and the increase per year was identical for both men and women [adjusted odds ratio (AOR) = 1.01, 95% CI 1.01, 1.03]. Overweight/obese men and women were more likely to be hypertensive (men, AOR = 3.32, 95% CI 2.16, 5.09; women, AOR = 1.70, 95% CI 1.21, 2.39). Overweight/obese women were more likely to work in business or as skilled workers (AOR = 6.24, 95% CI 1.18, 32.83) while overweight/obese men were more likely to work as government employees (AOR = 2.59, 95% CI 1.66, 4.03). Family history of hypertension was a significant correlate of overweight/obesity in men (P value 0.004) and women (P value 0.000). Overweight/obese men and women were less likely to use smokeless tobacco (men, AOR = 0.65, 95% CI 0.43, 0.97; women, AOR = 0.54, 95% CI 0.35, 0.85). CONCLUSION: The prevalence of risk factors for non-communicable diseases (NCDs) in Pakistan is expected to increase as further epidemiologic, nutritional and demographic changes occur. The assessment of excess body weight, and patterns and determinants of other risk factors for NCDs is important to provide useful guidelines in the planning of interventions to counter a growing problem.
We present the case of a 33-year-old nonatopic woman with multiple episodes of anaphylaxis after ingestion of different fruits. The fruits implicated were apple, banana and lychee: all of which belong to different and botanically disparate plant families. The reaction to apple and banana was confirmed by prick testing. There was no history of allergy to other agents that are known to have cross reactions with fruits, viz. latex or pollen. As such patients often do not present to dermatologists, we wish to highlight the rare but potentially fatal clinical entity of type I allergy to fruits without concomitant allergy to other common airborne/contact allergens. We also discuss the possible explanation of type I reaction to apparently unrelated fruits and the allergens involved in such reactions.
AIMS: The aim of the present study was to determine whether or not lipopolysaccharide from Actinobacillus actinomycetemcomitans could stimulate arginase activity in a murine macrophage cell line (RAW264.7 cells). METHODS: RAW264.7 cells were treated with A. actinomycetemcomitans-lipopolysaccharide or lipopolysaccharide from Escherichia coli for 24 h. The effect of polymyxin B, l-norvaline, dl-norvaline, dexamethasone and cytokines (interferon-gamma and interleukin-4) on arginase activity in A. actinomycetemcomitans-lipopolysaccharide-stimulated cells was also determined. The cells were pretreated with anti-CD14, anti -toll-like receptor 2, or anti-toll-like receptor 4 antibody prior to stimulation with A. actinomycetemcomitans-lipopolysaccharide. Arginase activity was determined by a colorimetric assay. RESULTS: A. actinomycetemcomitans-lipopolysaccharide stimulated arginase activity in RAW264.7 cells in a dose-dependent manner, but was less potent than E. coli-lipopolysaccharide. Polymyxin B and l-norvaline, but not dl-norvaline, blocked the arginase activity in A. actinomycetemcomitans-lipopolysaccharide-stimulated cells. Dexamethasone and interleukin-4 but not interferon-gamma augmented arginase activity in A. actinomycetemcomitans-lipopolysaccharide-stimulated cells. Treatment of the cells with anti-CD14 and anti-toll-like receptor 4 but not anti-toll-like receptor 2 antibody decreased arginase activity in A. actinomycetemcomitans-lipopolysaccharide-stimulated cells. CONCLUSION: The results of the present study suggest that lipopolysaccharide from A. actinomycetemcomitans via CD14/toll-like receptor 4 complex molecules and the regulatory control of glucocorticoid and cytokines may stimulate arginase activity in RAW264.7 cells.
AIMS: The aim of the present study was to determine the role of cyclic adenosine monophosphate (cAMP) on arginase activity in a murine macrophage cell line (RAW264.7 cells) stimulated with lipopolysaccharide (LPS) from Actinobacillus actinomycetemcomitans. MATERIALS AND METHODS: The cells were treated with A. actinomycetemcomitans LPS for 24 h. The effects of SQ22536 (an adenylyl cyclase inhibitor), ODQ (a guanylyl cyclase inhibitor), dibutyryl cAMP (a cAMP analog), 8-bromo cyclic guanosine monophosphate (a cGMP analog), forskolin (an adenylyl cylase activator), and cycloheximide (a protein synthesis inhibitor) on arginase activity in A. actinomycetemcomitans LPS-stimulated RAW264.7 cells were also determined. Arginase activity was assessed in LPS-stimulated cells in the presence of 3-isobutyl-1-methylxanthine (IBMX), siguazodan and rolipram [phosphodiesterase (PDE) inhibitors] as well as KT5720 [a protein kinase A (PKA) inhibitor]. RESULTS: Arginase activity in A. actinomycetemcomitans LPS-stimulated RAW264.7 cells was suppressed by SQ22536 but not ODQ. Enhancement of arginase activity was observed in the presence of cAMP analog or forskolin but not cGMP analog. Cycloheximide blocked arginase activity in the cells in the presence of cAMP analog or forskolin with or without A. actinomycetemcomitans LPS. IBMX augmented arginase activity in A. actinomycetemcomitans LPS-stimulated cells. Rolipram (a PDE4 inhibitor) increased the levels of arginase activity higher than siguazodan (a PDE3 inhibitor) in the antigen-stimulated cells. The effect of cAMP analog or forskolin on arginase activity in the presence or absence of A. actinomycetemcomitans LPS was blocked by the PKA inhibitor (KT5720). CONCLUSION: The results of the present study suggest that A. actinomycetemcomitans LPS may stimulate arginase activity in murine macrophages (RAW264.7 cells) in a cAMP-PKA-dependent pathway.
Food proteins can sensitize the infants via different sources. A 5-month-old boy suffered three episodes of generalized urticaria 20 min after the ingestion of a fruit purée containing apple, banana and orange. Skin testing showed positive results to banana and chestnut. Other tests were negative. The value of specific immunoglobulin E (Pharmacia CAP-FEIA, Uppsala, Sweden) to banana was 58 KU/l, to orange was 9.7 KU/l, to chestnut was 5.6 KU/l and to latex was 1.6 KU/l. Orange, apple and latex products were well tolerated. He never had eaten chestnut. The parents rejected a banana challenge test. The route of sensitization in our case might be via placenta, breast-milk, and inadvertent oral intake of food or even via inhalation. An early frequent exposure to banana allergens was considered a possibility factor for the development of banana sensitization. We found that the banana consumption during pregnancy and lactation by the mother of our patient was greater than usual. It is not frequent to find so high levels of sensitization to any fruit in first year of life. In our case, latex, chestnut and orange sensitizations did not seem to be clinically relevant. However, latex and foods known to cross-react with banana antigens should be given to banana-sensitive individuals with great caution.
Explore the source record for details and available documents.