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Sample records for cell frequency related

  1. Increased micronucleated cell frequency related to exposure to radiation emitted by computer cathode ray tube video display monitors

    Directory of Open Access Journals (Sweden)

    Karina Carbonari

    2005-09-01

    Full Text Available It is well recognized that electromagnetic fields can affect the biological functions of living organisms at both cellular and molecular level. The potential damaging effects of electromagnetic fields and very low frequency and extremely low frequency radiation emitted by computer cathode ray tube video display monitors (VDMs has become a concern within the scientific community. We studied the effects of occupational exposure to VDMs in 10 males and 10 females occupationally exposed to VDMs and 20 unexposed control subjects matched for age and sex. Genetic damage was assessed by examining the frequency of micronuclei in exfoliated buccal cells and the frequency of other nuclear abnormalities such as binucleated and broken egg cells. Although there were no differences regarding binucleated cells between exposed and control individuals our analysis revealed a significantly higher frequency of micronuclei (p < 0.001 and broken egg cells (p < 0.05 in individuals exposed to VDMs as compared to unexposed. We also found that the differences between individuals exposed to VDMs were significantly related to the sex of the individuals and that there was an increase in skin, central nervous system and ocular disease in the exposed individuals. These preliminary results indicate that microcomputer workers exposed to VDMs are at risk of significant cytogenetic damage and should periodically undergo biological monitoring.

  2. Extremely low-frequency electromagnetic fields affect transcript levels of neuronal differentiation-related genes in embryonic neural stem cells.

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    Qinlong Ma

    Full Text Available Previous studies have reported that extremely low-frequency electromagnetic fields (ELF-EMF can affect the processes of brain development, but the underlying mechanism is largely unknown. The proliferation and differentiation of embryonic neural stem cells (eNSCs is essential for brain development during the gestation period. To date, there is no report about the effects of ELF-EMF on eNSCs. In this paper, we studied the effects of ELF-EMF on the proliferation and differentiation of eNSCs. Primary cultured eNSCs were treated with 50 Hz ELF-EMF; various magnetic intensities and exposure times were applied. Our data showed that there was no significant change in cell proliferation, which was evaluated by cell viability (CCK-8 assay, DNA synthesis (Edu incorporation, average diameter of neurospheres, cell cycle distribution (flow cytometry and transcript levels of cell cycle related genes (P53, P21 and GADD45 detected by real-time PCR. When eNSCs were induced to differentiation, real-time PCR results showed a down-regulation of Sox2 and up-regulation of Math1, Math3, Ngn1 and Tuj1 mRNA levels after 50 Hz ELF-EMF exposure (2 mT for 3 days, but the percentages of neurons (Tuj1 positive cells and astrocytes (GFAP positive cells were not altered when detected by immunofluorescence assay. Although cell proliferation and the percentages of neurons and astrocytes differentiated from eNSCs were not affected by 50 Hz ELF-EMF, the expression of genes regulating neuronal differentiation was altered. In conclusion, our results support that 50 Hz ELF-EMF induce molecular changes during eNSCs differentiation, which might be compensated by post-transcriptional mechanisms to support cellular homeostasis.

  3. Effector memory T-cell frequencies in relation to tumour stage, location and HPV status in HNSCC patients

    NARCIS (Netherlands)

    A.W. Turksma; H.J. Bontkes; H. van den Heuvel; T.D. de Gruijl; B.M.E. von Blomberg; B.J.M. Braakhuis; C.R. Leemans; E. Bloemena; C.J.L.M. Meijer; E. Hooijberg

    2013-01-01

    Background The immune system plays an important role in tumour immune surveillance. Head and neck squamous cell carcinoma patients are often immune compromised. Objective To chart the baseline levels of T-cell subpopulation frequencies in patients with cancer prior to treatment. Subjects and methods

  4. Increased micronucleated cell frequency related to exposure to radiation emitted by computer cathode ray tube video display monitors

    OpenAIRE

    Karina Carbonari; Luciane Gonçalves; Daniela Roth; Patrick Moreira; Ricardo Fernández; Maria da Graça Martino-Roth

    2005-01-01

    It is well recognized that electromagnetic fields can affect the biological functions of living organisms at both cellular and molecular level. The potential damaging effects of electromagnetic fields and very low frequency and extremely low frequency radiation emitted by computer cathode ray tube video display monitors (VDMs) has become a concern within the scientific community. We studied the effects of occupational exposure to VDMs in 10 males and 10 females occupationally exposed to VDMs ...

  5. Monolithic cell for frequency conversion

    International Nuclear Information System (INIS)

    We report the successful design, assembly, and operation of a single cell for frequency conversion of Nd:glass laser radiation from lambda = 1054 nm to lambda = 351 nm. Our approach combines the highly energy-efficient polarization mismatch scheme previously conceived and developed with the simplicity of the tandem crystal approach recently demonstrated. The resultant monolithic conversion cell consists of two KDP Type II crystals, assembled with tuning axes orthogonal and contained between a single pair of windows. An index-matching liquid is used to eliminate reflections from all internal surfaces. In this paper we describe a simple birefringence-sensitive method for marking and orienting circular doubler and mixer crystals with tuning axes orthogonal to better than 60 seconds of arc. The monolithic cell design is described, with emphasis on the chemical compatibility of component materials (crystals, spacers, seals, and metal surfaces) with index-matching liquids. A comparison between Halocarbon and Koolase index-matching fluids, after several months of operation (greater than 400 shots), shows the latter to exhibit better long-term, photochemical stability. The performance of the monolithic cell is superior to that of separate doubler and mixer cells. It exhibits better long-term pointing stability and produces a cleaner 3 #betta# beam

  6. Assessment of the frequency of regulatory T cells (CD4+CD25+CD127-) in children with hemophilia A: relation to factor VIII inhibitors and disease severity.

    Science.gov (United States)

    El-Asrar, Mohamed Abo; Hamed, Ahmed El-Saeed; Darwish, Yasser Wagih; Ismail, Eman Abdel Rahman; Ismail, Noha Ali

    2016-01-01

    A rapidly growing evidence showed that regulatory T cells (Tregs) play a crucial role in tolerance to coagulation factors and may be involved in the pathogenesis of inhibitor formation in patients with hemophilia. We determined the percentage of Tregs (CD4CD25CD127) in 45 children with hemophilia A compared with 45 healthy controls, and assessed their relation to the clinical characteristics of patients and factor VIII (FVIII) inhibitors. Patients were studied stressing on frequency of bleeding attacks, joint pain, history of viral hepatitis, and the received therapy (FVIII precipitate/cryotherapy). FVIII activity and FVIII inhibitors were assessed with flow cytometric analysis of CD4CD25CD127 Tregs. According to residual FVIII activity levels, 30 patients (66.7%) had mild/moderate hemophilia A, whereas 15 (33.3%) patients had severe hemophilia A. The frequency of Tregs was significantly lower among all patients with hemophilia A compared with controls (2.59 ± 1.1 versus 3.73 ± 1.12%; P = 0.002). Tregs were significantly decreased among patients with FVIII inhibitors compared with the inhibitor-negative group (P hemophilia A had lower Tregs levels than those without (P = 0.34 and P = 0.011, respectively). A significant positive correlation was found between the percentage of Tregs and FVIII among hemophilia A patients. ROC curve analysis revealed that the cut-off value of Tregs at 1.91% could differentiate patients with and without FVIII inhibitors, with a sensitivity of 100% and a specificity of 91.3%. We suggest that alteration in the frequency of Tregs in young patients with hemophilia A may contribute to inhibitor formation and disease severity.

  7. Rank-frequency relation for Chinese characters

    CERN Document Server

    Deng, W B; Li, B; Wang, Q A

    2013-01-01

    The Zipf's law states that the ordered frequencies $f_1>f_2> ...$ of different words in a text hold $f_r\\propto r^{-\\gamma}$ with $\\gamma\\approx 1$ and rank $r$. The law applies to many languages with alphabetical writing systems, but was so far found to be absent for the rank-frequency relation of the Chinese characters, the main (and oldest) example of the logographic writing system. Here we show that the Zipf's law for Chinese characters perfectly holds for sufficiently short texts (few thousand different characters). The scenario of its validity is similar to the Zipf's law for words in short English texts. We focus on short texts, since for the sake of the rank-frequency analysis, long texts are just mixtures of shorter, thematically homogenous pieces. For long texts (or for mixtures of short texts), the Zipf's law holds for a relatively small range of ranks, but it is still important, since for all Chinese texts (we studied) it carries out $simeq 40%$ of the overall frequency. The previous results on th...

  8. 1D Modeling of a Bifacial Silicon Solar Cell under Frequency Modulation Monochromatic Illumination: Determination of the Equivalent Electrical Circuit Related to the Surface Recombination Velocity

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    H. Ly Diallo

    2012-06-01

    Full Text Available We present in this study the determination of the equivalent electrical circuits associated to the recombination velocities for a bifacial silicon solar cell under frequency modulation and monochromatic illumination. This determination is based on Bode and Nyquist diagrams that is the variations of the phase and the module of the back surface and intrinsic junction recombination velocities. Their dependence on illumination wavelength is also shown.

  9. Increased frequency and compromised function of T regulatory cells in systemic sclerosis (SSc is related to a diminished CD69 and TGFbeta expression.

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    Timothy R D J Radstake

    Full Text Available BACKGROUND: Regulatory T cells (Tregs are essential in the control of tolerance. Evidence implicates Tregs in human autoimmune conditions. Here we investigated their role in systemic sclerosis (SSc. METHODS/PRINCIPAL FINDINGS: Patients were subdivided as having limited cutaneous SSc (lcSSc, n = 20 or diffuse cutaneous SSc (dcSSc, n = 48. Further subdivision was made between early dcSSc (n = 24 and late dcSSc (n = 24 based upon the duration of disease. 26 controls were studied for comparison. CD3+ cells were isolated using FACS and subsequently studied for the expression of CD4, CD8, CD25, FoxP3, CD127, CD62L, GITR, CD69 using flow cytometry. T cell suppression assays were performed using sorted CD4CD25(highCD127(- and CD4CD25(lowCD127(high and CD3(+ cells. Suppressive function was correlated with CD69 surface expression and TGFbeta secretion/expression. The frequency of CD4(+CD25(+ and CD25(highFoxP3(highCD127(neg T cells was highly increased in all SSc subgroups. Although the expression of CD25 and GITR was comparable between groups, expression of CD62L and CD69 was dramatically lower in SSc patients, which correlated with a diminished suppressive function. Co-incubation of Tregs from healthy donors with plasma from SSc patients fully abrogated suppressive activity. Activation of Tregs from healthy donors or SSc patients with PHA significantly up regulated CD69 expression that could be inhibited by SSc plasma. CONCLUSIONS/SIGNIFICANCE: These results indicate that soluble factors in SSc plasma inhibit Treg function specifically that is associated with altered Treg CD69 and TGFbeta expression. These data suggest that a defective Treg function may underlie the immune dysfunction in systemic sclerosis.

  10. On the frequency-apparent magnitude relations

    Energy Technology Data Exchange (ETDEWEB)

    Tinti, S.; Rimondi, R.; Mulargia, F.

    1987-08-01

    The ''apparent magnitude'' of an earthquake is the observed magnitude value and differs from the true magnitude in virtue of the experimental error. If the error is assumed to be normally distributed with standard deviation sigma, the probability distributions of the two magnitudes may be proven to be in a rather simple relationship, at least for the cases of seismological interest. In fact, there is a significant interval of magnitudes where the suggested approximation in the text holds. The main consequence is that, independently of the assumed basic distribution of the true magnitude, the exceedence frequencies appearing from the observed data are larger than the true ones and therefore their values should be corrected by an appropriate reducing factor.

  11. Investigation of CD4~+ CXCR5~+ follicular helper T cell frequency and expression of related functional molecules in peripheral blood of hepatitis C virus patients

    Institute of Scientific and Technical Information of China (English)

    王宇

    2013-01-01

    Objective To determine whether hepatitis C virus (HCV) infection is associated with increased frequency of the CD4+follicular helper T (Tfh) subset in peripheral blood and to investigate their potential function contribution to the HCV-induced immune response by

  12. Temporal logic for properties with relative frequency

    OpenAIRE

    Decker, Normann

    2011-01-01

    Inherently unreliable or fault-tolerant systems demand for a specification formalism that allows the user to express a required ratio of certain observations. Such a requirement can be, e.g. that deadlines in a real-time system must be met in at least 80% of all cases. Logics and in particular temporal logics provide powerful, flexible and well established specification formalisms. We therefore propose fLTL, an extension to linear-time temporal logic that allows for expressing relative freque...

  13. Size-frequency and rank-frequency relations,power laws and exponentials: a unified approach

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Power laws, such as Zipf's law, and exponential relations, leading to straight lines in logarithmic or semi-logarithmic scales, are presented in a unified setting. It is shown that the class of size-frequency power laws is larger than the class of rank-frequency power laws. Their ubiquity in all fields of science is illustrated.

  14. Frequency Selective Surfaces with Nanoparticles Unit Cell

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    Nga Hung Poon

    2015-09-01

    Full Text Available The frequency selective surface (FSS is a periodic structure with filtering performance for optical and microwave signals. The general periodic arrays made with patterned metallic elements can act as an aperture or patch on a substrate. In this work, two kinds of materials were used to produce unit cells with various patterns. Gold nanoparticles of 25 nm diameter were used to form periodic monolayer arrays by a confined photocatalytic oxidation-based surface modification method. As the other material, silver gel was used to create multiple layers of silver. Due to the ultra-thin nature of the self-assembled gold nanoparticle monolayer, it is very easy to penetrate the FSS with terahertz radiation. However, the isolated silver islands made from silver gel form thicker multiple layers and contribute to much higher reflectance. This work demonstrated that multiple silver layers are more suitable than gold nanoparticles for use in the fabrication of FSS structures.

  15. Feeding Frequency Affects Cultured Rat Pituitary Cells in Low Gravity

    Science.gov (United States)

    Hymer, W. C.; Grindeland, R. E.; Salada, T.; Cenci, R.; Krishnan, K.; Mukai, C.; Nagaoka, S.

    1996-01-01

    In this report, we describe the results of a rat pituitary cell culture experiment done on STS-65 in which the effect of cell feeding on the release of the six anterior pituitary hormones was studied. We found complex microgravity related interactions between the frequency of cell feeding and the quantity and quality (i.e. biological activity) of some of the six hormones released in flight. Analyses of growth hormone (GH) released from cells into culture media on different mission days using gel filtration and ion exchange chromatography yielded qualitatively similar results between ground and flight samples. Lack of cell feeding resulted in extensive cell clumping in flight (but not ground) cultures. Vigorous fibroblast growth occurred in both ground and flight cultures fed 4 times. These results are interpreted within the context of autocrine and or paracrine feedback interactions. Finally the payload specialist successfully prepared a fresh trypsin solution in microgravity, detached the cells from their surface and reinserted them back into the culture chamber. These cells reattached and continued to release hormone in microgravity. In summary, this experiment shows that pituitary cells are microgravity sensitive and that coupled operations routinely associated with laboratory cel1 culture can also be accomplished in low gravity.

  16. Resonant-frequency discharge in a multi-cell radio frequency cavity

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, S; Upadhyay, J; Mammosser, J; Nikolic, M; Vuskovic, L

    2014-11-07

    We are reporting experimental results on microwave discharge operating at resonant frequency in a multi-cell radio frequency (RF) accelerator cavity. Although the discharge operated at room temperature, the setup was constructed so that it could be used for plasma generation and processing in fully assembled active superconducting radio-frequency (SRF) cryomodule (in situ operation). This discharge offers an efficient mechanism for removal of a variety of contaminants, organic or oxide layers, and residual particulates from the interior surface of RF cavities through the interaction of plasma-generated radicals with the cavity walls. We describe resonant RF breakdown conditions and address the problems related to generation and sustaining the multi-cell cavity plasma, which are breakdown and resonant detuning. We have determined breakdown conditions in the cavity, which was acting as a plasma vessel with distorted cylindrical geometry. We discuss the spectroscopic data taken during plasma removal of contaminants and use them to evaluate plasma parameters, characterize the process, and estimate the volatile contaminant product removal.

  17. New sample cell configuration for wide-frequency dielectric spectroscopy: DC to radio frequencies.

    Science.gov (United States)

    Nakanishi, Masahiro; Sasaki, Yasutaka; Nozaki, Ryusuke

    2010-12-01

    A new configuration for the sample cell to be used in broadband dielectric spectroscopy is presented. A coaxial structure with a parallel plate capacitor (outward parallel plate cell: OPPC) has made it possible to extend the frequency range significantly in comparison with the frequency range of the conventional configuration. In the proposed configuration, stray inductance is significantly decreased; consequently, the upper bound of the frequency range is improved by two orders of magnitude from the upper limit of conventional parallel plate capacitor (1 MHz). Furthermore, the value of capacitance is kept high by using a parallel plate configuration. Therefore, the precision of the capacitance measurement in the lower frequency range remains sufficiently high. Finally, OPPC can cover a wide frequency range (100 Hz-1 GHz) with an appropriate admittance measuring apparatus such as an impedance or network analyzer. The OPPC and the conventional dielectric cell are compared by examining the frequency dependence of the complex permittivity for several polar liquids and polymeric films.

  18. Frequency of aneuploidy related to age in porcine oocytes.

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    Miroslav Hornak

    Full Text Available It is generally accepted that mammalian oocytes are frequently suffering from chromosome segregation errors during meiosis I, which have severe consequences, including pregnancy loss, developmental disorders and mental retardation. In a search for physiologically more relevant model than rodent oocytes to study this phenomenon, we have employed comparative genomic hybridization (CGH, combined with whole genome amplification (WGA, to study the frequency of aneuploidy in porcine oocytes, including rare cells obtained from aged animals. Using this method, we were able to analyze segregation pattern of each individual chromosome during meiosis I. In contrast to the previous reports where conventional methods, such as chromosome spreads or FISH, were used to estimate frequency of aneuploidy, our results presented here show, that the frequency of this phenomenon was overestimated in porcine oocytes. Surprisingly, despite the results from human and mouse showing an increase in the frequency of aneuploidy with advanced maternal age, our results obtained by the most accurate method currently available for scoring the aneuploidy in oocytes indicated no increase in the frequency of aneuploidy even in oocytes from animals, whose age was close to the life expectancy of the breed.

  19. Frequency of aneuploidy related to age in porcine oocytes.

    Science.gov (United States)

    Hornak, Miroslav; Jeseta, Michal; Musilova, Petra; Pavlok, Antonin; Kubelka, Michal; Motlik, Jan; Rubes, Jiri; Anger, Martin

    2011-04-27

    It is generally accepted that mammalian oocytes are frequently suffering from chromosome segregation errors during meiosis I, which have severe consequences, including pregnancy loss, developmental disorders and mental retardation. In a search for physiologically more relevant model than rodent oocytes to study this phenomenon, we have employed comparative genomic hybridization (CGH), combined with whole genome amplification (WGA), to study the frequency of aneuploidy in porcine oocytes, including rare cells obtained from aged animals. Using this method, we were able to analyze segregation pattern of each individual chromosome during meiosis I. In contrast to the previous reports where conventional methods, such as chromosome spreads or FISH, were used to estimate frequency of aneuploidy, our results presented here show, that the frequency of this phenomenon was overestimated in porcine oocytes. Surprisingly, despite the results from human and mouse showing an increase in the frequency of aneuploidy with advanced maternal age, our results obtained by the most accurate method currently available for scoring the aneuploidy in oocytes indicated no increase in the frequency of aneuploidy even in oocytes from animals, whose age was close to the life expectancy of the breed.

  20. Frequency and outcome of treatment in polycystic ovaries related infertility

    OpenAIRE

    Arain, Farzana; Arif, Nesreen; Halepota, Hafeez

    2015-01-01

    Background: Infertility is defined as inability of couple to conceive after one year of unprotected intercourse. The prevalence of infertility in Pakistan is 21.9%. The most common cause of medically treatable infertility is polycystic ovarian syndrome (PCO). This study was conducted to see the frequency and outcome of treatment in PCOs related infertility in infertile couples coming to Mohammad Medical College Hospital, Mirpurkhas, Sindh. Methods: This prospective observational study was con...

  1. CRITICAL ILLUMINATION AND FLICKER FREQUENCY IN RELATED FISHES.

    Science.gov (United States)

    Crozier, W J; Wolf, E; Zerrahn-Wolf, G

    1937-09-20

    Flicker response curves have been obtained at 21.5 degrees C. for three genera of fresh water teleosts: Enneacanthus (sunfish), Xiphophorus (swordtail), Platypoecilius (Platy), by the determination of mean critical intensities for response at fixed flicker frequencies, and for a certain homogeneous group of backcross hybrids of swordtail x Platy (Black Helleri). The curves exhibit marked differences in form and proportions. The same type of analysis is applicable to each, however. A low intensity rod-governed section has added to it a more extensive cone portion. Each part is accurately described by the equation F = F(max.)/(1 + e(-p log(-p logI/I(i) ) )), where F = flicker frequency, I = associated mean critical intensity, and I(i) is the intensity at the inflection point of the sigmoid curve relating F to log I. There is no correlation between quantitative features of the rod and cone portions. Threshold intensities, p, I(i), and F(max.) are separately and independently determined. The hybrid Black Helleri show quantitative agreement with the Xiphophorus parental stock in the values of p for rods and cones, and in the cone F(max.); the rod F(max.) is very similar to that for the Platy stock; the general level of effective intensities is rather like that of the Platy form. This provides, among other things, a new kind of support for the duplicity doctrine. Various races of Platypoecilius maculatus, and P. variatus, give closely agreeing values of I(m) at different flicker frequencies; and two species of sunfish also agree. The effect of cross-breeding is thus not a superficial thing. It indicates the possibility of further genetic investigation. The variability of the critical intensity for response to flicker follows the rules previously found to hold for other forms. The variation is the expression of a property of the tested organism. It is shown that, on the assumption of a frequency distribution of receptor element thresholds as a function of log I, with

  2. Relative frequency and survival of primary cutaneous lymphomas: a retrospective analysis of 98 patients

    Institute of Scientific and Technical Information of China (English)

    Liu Jie; Yu Xin; Liu Yuehua; Jin Hongzhong; Ma Donglai; Qu Tao; Wang Tao

    2014-01-01

    Background The World Health Organization and European Organization for Research and Treatment of Cancer (WHOEORTC) classification in 2005 promoted the comparisons of primary cutaneous lymphoma (PCL) subtypes between different countries.The relative frequency of PCL varied according to geography.The study aimed to analyze the relative frequency and survival of PCLs in China and to compare the data with the published results from other countries.Methods We analyzed 98 patients with PCLs over a 6-year period and reclassified them according to the most recent WHO-EORTC classification (2005).Disease-specific survival rate and curves according to specific subtypes such as mycosis fungoides,lymphomatoid papulosis,and primary cutaneous peripheral T-cell lymphoma,unspecified was also calculated.Results The relative rate of PCL in China was distinct from those in Western countries.Our study showed a higher frequency of cutaneous T-and NK-cell lymphomas (CTCLs) (94%),and a lower frequency of cutaneous B-cell lymphomas (CBCLs) (6%).The 5-year survival rate of the total PCLs was 82%.There was no significant difference in the 5-year survival rate (P >0.05 by Log-rank test) between CTCL (80%) and CBCL (100%).Conclusions The higher percentage of CTCL in China may provide a clue to further study the etiological factors of PCLs.Racial variations in factors such as HLA determinants may play a role in the development of CTCL.

  3. Frequency and distribution of Notch mutations in tumor cell lines

    International Nuclear Information System (INIS)

    Deregulated Notch signaling is linked to a variety of tumors and it is therefore important to learn more about the frequency and distribution of Notch mutations in a tumor context. In this report, we use data from the recently developed Cancer Cell Line Encyclopedia to assess the frequency and distribution of Notch mutations in a large panel of cancer cell lines in silico. Our results show that the mutation frequency of Notch receptor and ligand genes is at par with that for established oncogenes and higher than for a set of house-keeping genes. Mutations were found across all four Notch receptor genes, but with notable differences between protein domains, mutations were for example more prevalent in the regions encoding the LNR and PEST domains in the Notch intracellular domain. Furthermore, an in silico estimation of functional impact showed that deleterious mutations cluster to the ligand-binding and the intracellular domains of NOTCH1. For most cell line groups, the mutation frequency of Notch genes is higher than in associated primary tumors. Our results shed new light on the spectrum of Notch mutations after in vitro culturing of tumor cells. The higher mutation frequency in tumor cell lines indicates that Notch mutations are associated with a growth advantage in vitro, and thus may be considered to be driver mutations in a tumor cell line context. The online version of this article (doi:10.1186/s12885-015-1278-x) contains supplementary material, which is available to authorized users

  4. The Genetic Landscape of Hematopoietic Stem Cell Frequency in Mice

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    Xiaoying Zhou

    2015-07-01

    Full Text Available Prior efforts to identify regulators of hematopoietic stem cell physiology have relied mainly on candidate gene approaches with genetically modified mice. Here we used a genome-wide association study (GWAS strategy with the hybrid mouse diversity panel to identify the genetic determinants of hematopoietic stem/progenitor cell (HSPC frequency. Among 108 strains, we observed ∼120- to 300-fold variation in three HSPC populations. A GWAS analysis identified several loci that were significantly associated with HSPC frequency, including a locus on chromosome 5 harboring the homeodomain-only protein gene (Hopx. Hopx previously had been implicated in cardiac development but was not known to influence HSPC biology. Analysis of the HSPC pool in Hopx−/− mice demonstrated significantly reduced cell frequencies and impaired engraftment in competitive repopulation assays, thus providing functional validation of this positional candidate gene. These results demonstrate the power of GWAS in mice to identify genetic determinants of the hematopoietic system.

  5. Magnetic Force Nanoprobe for Direct Observation of Audio Frequency Tonotopy of Hair Cells.

    Science.gov (United States)

    Kim, Ji-Wook; Lee, Jae-Hyun; Ma, Ji-Hyun; Chung, Eunna; Choi, Hongsuh; Bok, Jinwoong; Cheon, Jinwoo

    2016-06-01

    Sound perception via mechano-sensation is a remarkably sensitive and fast transmission process, converting sound as a mechanical input to neural signals in a living organism. Although knowledge of auditory hair cell functions has advanced over the past decades, challenges remain in understanding their biomechanics, partly because of their biophysical complexity and the lack of appropriate probing tools. Most current studies of hair cells have been conducted in a relatively low-frequency range (perception of 20 kHz or higher. Here, we demonstrate that the magnetic force nanoprobe (MFN) has superb spatiotemporal capabilities to mechanically stimulate spatially-targeted individual hair cells with a temporal resolution of up to 9 μs, which is equivalent to approximately 50 kHz; therefore, it is possible to investigate avian hair cell biomechanics at different tonotopic regions of the cochlea covering a full hearing frequency range of 50 to 5000 Hz. We found that the variation of the stimulation frequency and amplitude of hair bundles creates distinct mechanical responsive features along the tonotopic axis, where the kinetics of the hair bundle recovery motion exhibits unique frequency-dependent characteristics: basal, middle, and apical hair bundles can effectively respond at their respective ranges of frequency. We revealed that such recovery kinetics possesses two different time constants that are closely related to the passive and active motilities of hair cells. The use of MFN is critical for the kinetics study of free-standing hair cells in a spatiotemporally distinct tonotopic organization. PMID:27215487

  6. Nightmare frequency is related to a propensity for mirror behaviors.

    Science.gov (United States)

    Nielsen, Tore; Powell, Russell A; Kuiken, Don

    2013-12-01

    We previously reported that college students who indicated engaging in frequent dream-enacting behaviors also scored high on a new measure of mirror behaviors, which is the propensity to imitate another person's emotions or actions. Since dream-enacting behaviors are frequently the culmination of nightmares, one explanation for the observed relationship is that individuals who frequently display mirror behaviors are also prone to nightmares. We used the Mirror Behavior Questionnaire (MBQ) and self-reported frequencies of nightmares to assess this possibility. A sample of 480 students, consisting of 188 males (19.2±1.73 years) and 292 females (19.0±1.55 years) enrolled in a first-year university psychology course, participated for course credit. They completed a battery of questionnaires that included the 16-item MBQ, plus an item about nightmare frequency (NMF) in the past 30 days. NMF scores were split to create low, medium, and high NMF groups. MBQ total scores were significantly higher for female than for male subjects, but an interaction revealed that this was true only for Hi-NMF subjects. MBQ Factor 4, Motor Skill Imitation, paralleled this global interaction for females, whereas MBQ Factor 3, Sleepiness/Anger Contagion, was elevated only for Hi-NMF males. Item analyses indicated that Hi- and Med-NMF females scored higher than Lo-NMF females on the 3 items of Factor 4 that reflect voluntary imitation (imitating famous/cartoon voices, being a physically active spectator, and learning new skills by observing), as well as on 2 other items that reflect involuntary imitation (contagious yawning and self-rated empathy). Although Hi- and Lo-NMF males differed most clearly on the sleepiness item of Factor 3, all 3 items on this factor (including anger contagion and contagious yawning) are plausibly associated with perception of and response to social threat. Results provide evidence that among females nightmares are associated with voluntary and involuntary mirror

  7. Factors Related to Coital Frequency of Women in Their Thirties.

    Science.gov (United States)

    da Silva Lara, Lúcia Alves; Dos Santos Lima, Maria Lucia; Romão, Gustavo Salata; Ferriani, Rui Alberto; de Albuquerque Salles Navarro, Paula Andrea

    2016-07-01

    This cross-sectional study aimed to identify factors related to coital frequency (CF) among 254 women in their 30s using a semistructured interview to collect sociodemographic, anthropometric, reproductive, clinical, and relationship data. CF was characterized as (a) never, (b) rarely (≤1 times/month), (c) occasionally (≤1 times /week), (d) regularly (2-3 times/week), or (e) frequently (>3 times/week). The mean age was 34.38 ± 0.43 years, mean body mass index (BMI) was 27.86 ± 6.52 kg, mean family income was US$1,044.18 ± 796.19, mean number of children was 1.71 ± 0.89, and mean relationship duration was 8.87 ± 5.11 years. Eighty-seven women (35.2%) were taking hormonal contraceptives, 143 (98.0%) were employed, 239 (96.48%) had a secondary or higher education, and 9 (3.62%) had primary schooling. CF was classified as >3 times/week in 22 (8.66%), 2-3 times/week for 98 (38.58%), ≤1 times/week in 40 (15.75%), ≤1 times/month in 14 (5.51%), and never in 5 (1.97%). Women who reported having coitus >3 times/week a week had significantly higher body mass index (BMI; 32.72 ± 7.42 kg/m(2)) than those who had coitus 2-3 times/week (28.45 ± 6.76 kg/m(2)) and ≤1 times /week (26.81 ± 5.39 kg/m(2)) (p < 0.01 for both comparisons). Thus, coital frequency varies in women in their 30s. Obese women had a higher CF than normal-weight and overweight women. PMID:26036273

  8. Increased somatic cell mutant frequency in atomic bomb survivors

    International Nuclear Information System (INIS)

    Frequencies of mutant T-cells in peripheral blood, which are deficient in the activity of hypoxanthine guanine phosphoribosyltransferase (HPRT) were determined for atomic bomb survivors by direct clonal assay using a previously reported method. Results from 30 exposed survivors (exposed to more than 1 rad) and 17 age- and sex-matched controls (exposed to less than 1 rad) were analyzed. The mean mutant frequency (Mf) in the exposed (5.2 x 10-6; range 0.8 - 14.4 x 10-6) was significantly higher than in controls (3.4 x 10-6; range 1.3 - 9.3 x 10-6), a fact not attributable to lower nonmutant cell cloning efficiencies in the exposed group since cell cloning efficiencies were virtually identical in both groups. An initial analysis of the data did not reveal a significant correlation between individual Mfs and individual radiation dose estimates when the latter were defined by the original, tentative estimates (T65D), even though there was a significant positive correlation of Mfs with individual frequency of lymphocytes bearing chromosome aberration. However, reanalysis using the newer revised individual dose estimates (DS86) for 27 exposed survivors and 17 controls did reveal a significant but shallow positive correlation between T-cell Mf values and individual exposure doses. These results indicate that HPRT mutation in vivo in human T-cells could be detected in these survivors 40 years after the presumed mutational event. (author)

  9. Investigations of laser pumped gas cell atomic frequency standard

    Science.gov (United States)

    Volk, C. H.; Camparo, J. C.; Fueholz, R. P.

    1982-01-01

    The performance characteristics of a rubidium gas cell atomic frequency standard might be improved by replacing the standard rubidium discharge lamp with a single mode laser diode. Aspects of the laser pumped gas cell atomic clock studied include effects due to laser intensity, laser detuning, and the choice of the particular atomic absorption line. Results indicate that the performance of the gas cell clock may be improved by judicious choice of the operating parameters of the laser diode. The laser diode also proved to be a valuable tool in investigating the operation of the conventional gas cell clock. Results concerning linewidths, the light shift effect and the effect of isotopic spin exchange in the conventional gas cell clock are reported.

  10. Omega 3 fatty acids reduce myeloid progenitor cell frequency in the bone marrow of mice and promote progenitor cell differentiation

    Directory of Open Access Journals (Sweden)

    Sollars Vincent E

    2009-03-01

    Full Text Available Abstract Background Omega 3 fatty acids have been found to inhibit proliferation, induce apoptosis, and promote differentiation in various cell types. The processes of cell survival, expansion, and differentiation are of key importance in the regulation of hematopoiesis. We investigated the role of omega 3 fatty acids in controlling the frequency of various myeloid progenitor cells in the bone marrow of mice. Increased progenitor cell frequency and blocked differentiation are characteristics of hematopoietic disorders of the myeloid lineage, such as myeloproliferative diseases and myeloid leukemias. Results We found that increasing the proportion of omega 3 fatty acids relative to the proportion of omega 6 fatty acids in the diet caused increased differentiation and reduced the frequency of myeloid progenitor cells in the bone marrow of mice. Furthermore, this had no adverse effect on peripheral white blood cell counts. Conclusion Our results indicate that omega 3 fatty acids impact hematopoietic differentiation by reducing myeloid progenitor cell frequency in the bone marrow and promoting progenitor cell differentiation. Further exploration of this discovery could lead to the use of omega 3 fatty acids as a therapeutic option for patients that have various disorders of hematopoiesis.

  11. Radio-frequency-modulated Rydberg states in a vapor cell

    CERN Document Server

    Miller, Stephanie A; Raithel, Georg

    2016-01-01

    We measure strong radio-frequency (RF) electric fields using rubidium Rydberg atoms prepared in a room-temperature vapor cell as field sensors. Electromagnetically induced transparency is employed as an optical readout. We RF-modulate the 60$S_{1/2}$ and 58$D_{5/2}$ Rydberg states with 50~MHz and 100~MHz fields, respectively. For weak to moderate RF fields, the Rydberg levels become Stark-shifted, and sidebands appear at even multiples of the driving frequency. In high fields, the adjacent hydrogenic manifold begins to intersect the shifted levels, providing rich spectroscopic structure suitable for precision field measurements. A quantitative description of strong-field level modulation and mixing of $S$ and $D$ states with hydrogenic states is provided by Floquet theory. Additionally, we estimate the shielding of DC electric fields in the interior of the glass vapor cell.

  12. Silicon pin solar cells investigated by multi-frequency EDMR

    Energy Technology Data Exchange (ETDEWEB)

    Meier, Christoph; Teutloff, Christian; Behrends, Jan; Bittl, Robert [Fachbereich Physik, Freie Universitaet Berlin, Arnimallee 14, 14195 Berlin (Germany); Fehr, Matthias; Schnegg, Alexander; Lips, Klaus [Institut fuer Silizium-Photovoltaik, Helmholtz-Zentrum Berlin fuer Materialien und Energie, Kekulestr. 5, 12489 Berlin (Germany)

    2011-07-01

    Electrically detected magnetic resonance (EDMR) can be used to investigate paramagnetic centres influencing charge transport in semiconductors even at concentrations well below the sensitivity threshold of conventional electron paramagnetic resonance (EPR). This technique measures conductivity changes in the sample that occur when spin transitions cause an enhancement or a quenching of currents. EDMR was e.g. successfully employed to microcrystalline Si pin solar cells in X-band (9.7 GHz). We present the application of EDMR to Si pin solar cells at Q-band frequency (34 GHz). We could demonstrate a gain of spectral resolution. With multi-frequency EDMR we distinguished between field-dependent and field-independent interactions. Further, we realized EDMR in a non-resonant setup at 94 GHz (W-band) and show first results.

  13. Low-frequency quantitative ultrasound imaging of cell death in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi-Naini, Ali; Falou, Omar; Czarnota, Gregory J. [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Department of Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Papanicolau, Naum; Tadayyon, Hadi [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Lee, Justin [Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5 (Canada); Zubovits, Judit [Department of Pathology, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Sadeghian, Alireza [Department of Computer Science, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Karshafian, Raffi [Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada); Al-Mahrouki, Azza; Giles, Anoja [Imaging Research – Physical Science, Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5, Canada and Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario M4N 3M5 (Canada); Kolios, Michael C. [Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario M4N 3M5, Canada and Department of Physics, Ryerson University, Toronto, Ontario M5B 2K3 (Canada)

    2013-08-15

    Purpose: Currently, no clinical imaging modality is used routinely to assess tumor response to cancer therapies within hours to days of the delivery of treatment. Here, the authors demonstrate the efficacy of ultrasound at a clinically relevant frequency to quantitatively detect changes in tumors in response to cancer therapies using preclinical mouse models.Methods: Conventional low-frequency and corresponding high-frequency ultrasound (ranging from 4 to 28 MHz) were used along with quantitative spectroscopic and signal envelope statistical analyses on data obtained from xenograft tumors treated with chemotherapy, x-ray radiation, as well as a novel vascular targeting microbubble therapy.Results: Ultrasound-based spectroscopic biomarkers indicated significant changes in cell-death associated parameters in responsive tumors. Specifically changes in the midband fit, spectral slope, and 0-MHz intercept biomarkers were investigated for different types of treatment and demonstrated cell-death related changes. The midband fit and 0-MHz intercept biomarker derived from low-frequency data demonstrated increases ranging approximately from 0 to 6 dBr and 0 to 8 dBr, respectively, depending on treatments administrated. These data paralleled results observed for high-frequency ultrasound data. Statistical analysis of ultrasound signal envelope was performed as an alternative method to obtain histogram-based biomarkers and provided confirmatory results. Histological analysis of tumor specimens indicated up to 61% cell death present in the tumors depending on treatments administered, consistent with quantitative ultrasound findings indicating cell death. Ultrasound-based spectroscopic biomarkers demonstrated a good correlation with histological morphological findings indicative of cell death (r{sup 2}= 0.71, 0.82; p < 0.001).Conclusions: In summary, the results provide preclinical evidence, for the first time, that quantitative ultrasound used at a clinically relevant frequency

  14. Quantifying Discipline Practices Using Absolute vs. Relative Frequencies: Clinical and Research Implications for Child Welfare

    OpenAIRE

    Lindhiem, Oliver; Shaffer, Anne; Kolko, David J.

    2013-01-01

    In the parent intervention outcome literatures, discipline practices are generally quantified as absolute frequencies or, less commonly, as relative frequencies. These differences in methodology warrant direct comparison as they have critical implications for study results and conclusions among treatments targeted at reducing parental aggression and harsh discipline. In this study, we directly compared the absolute frequency method and the relative frequency method for quantifying physically ...

  15. Refraction Frequency, for Orchestra: A Discussion of Related Elements

    OpenAIRE

    Mehinovic, Vedran /

    2012-01-01

    The following discussion addresses Refraction Frequency, an orchestral work that draws material from distinct disciplines and utilizes extremely contrasting compositional approaches. The textural complexity contains elements akin to some found in Korean traditional music, where vibrato is an integral expressive device, and spectral noise naturally present within sound is brought out. The emphasis on slower progression of events, particularly evident in rich, gradually-shifting formations is a...

  16. The nature of high frequency sister chromatid exchange cells (HFCs).

    Science.gov (United States)

    Ponzanelli, I; Landi, S; Bernacchi, F; Barale, R

    1997-09-01

    We employed the three-way differential staining technique (TWD), which allows SCEs to be distinguished on a per generation basis by scoring third metaphases (M3), in order to study the spontaneous levels of SCEs in normal and high frequency cells (HFCs) that occurred in the first (S1), second (S2) and third (S3) S phases. Fifty one of 900 lymphocytes from 37 healthy donors were defined as HFCs by calculating the 95th percentile of the distribution of SCEs in S1 + S2. 'Normal' cells presented almost the same number of SCEs after the first, second and third cell cycles (SCE averages of 2.43, 2.04 and 3.53 respectively). In contrast, HFCs showed a higher SCE count in S1, which decreased rapidly through the cycles and reached baseline level at S3 (SCE averages of 7.18, 4.29 and 3.45 respectively). This would suggest that the lesions responsible for the higher SCE frequency in HFCs were effectively removed after two cell cycles and strongly support the hypothesis that HFCs are lymphocytes which accumulate higher levels of DNA lesions through time. PMID:9379910

  17. Frequency locking in hair cells: Distinguishing between distinct resonant mechanisms

    CERN Document Server

    Edri, Yuval; Yochelis, Arik

    2016-01-01

    The auditory system displays remarkable mechanical sensitivity and frequency discrimination. These attributes have been shown to rely on an amplification process, which requires biochemical feedback loops. In some systems, the active process was shown to lead to spontaneous oscillations of hair cell bundles. In the last decade, models that display proximity to an oscillatory onset (a.k.a. Hopf bifurcation) have gained increasing support due to many advantages in explaining the hearing phenomenology. Particularly, they exhibit resonant responses to distinct frequencies of incoming sound waves. Unlike previous studies, two types of driving forces are being examined: additive, in which the external forcing term does not couple directly on the systems observable (passive coupling), and parametric, in which the forcing term directly affects the observable and thus intrinsically modifies the systems properties (active coupling). By applying universal principles near the Hopf bifurcation onset, we find several funda...

  18. Effects of knowledge of results (KR) frequency in the learning of a timing skill: absolute versus relative KR frequency.

    Science.gov (United States)

    Vieira, Márcio M; Ugrinowitsch, Herbert; Oliveira, Fernanda S; Gallo, Lívia G; Benda, Rodolfo N

    2012-10-01

    The interaction between the amount of practice and frequency of Knowledge of Results (KR) was investigated in a timing skill. In the acquisition phase the task involved 90 trials of releasing a knob and transporting three tennis balls from three near recipients to three far ones in a specific sequence and target time. The retention test performed 24 hr. later had the same sequence of transport but a new target time was required. In both phases, absolute error and standard deviation plus constant error was measured. The five groups differed in relation to frequency of KR and amount of practice. The results showed that intermediate frequencies as well as higher frequencies of KR elicited better performance during the retention test.

  19. FREQUENCY CATASTROPHE AND CO-EXISTING ATTRACTORS IN A CELL Ca2+ NONLINEAR OSCILLATION MODEL WITH TIME DELAY*

    Institute of Scientific and Technical Information of China (English)

    应阳君; 黄祖洽

    2001-01-01

    Frequency catastrophe is found in a cell Ca2+ nonlinear oscillation model with time delay. The relation of the frequency transition to the time delay is studied by numerical simulations and theoretical analysis. There is a range of parameters in which two kinds of attractors with great frequency differences co-exist in the system. Along with parameter changes, a critical phenomenon occurs and the oscillation frequency changes greatly. This mechanism helps us to deepen the understanding of the complex dynamics of delay systems, and might be of some meaning in cell signalling.

  20. Frequency patterns of T-cell exposed motifs in immunoglobulin heavy chain peptides presented by MHCs

    Directory of Open Access Journals (Sweden)

    Robert D. Bremel

    2014-10-01

    Full Text Available Immunoglobulins are highly diverse protein sequences that are processed and presented to T-cells by B-cells and other antigen presenting cells. We examined a large dataset of immunoglobulin heavy chain variable regions (IGHV to assess the diversity of T-cell exposed motifs (TCEM. TCEM comprise those amino acids in a MHC-bound peptide which face outwards, surrounded by the MHC histotope, and which engage the T-cell receptor. Within IGHV there is a distinct pattern of predicted MHC class II binding and a very high frequency of re-use of the TCEMs. The re-use frequency indicates that only a limited number of different cognate T-cells are required to engage many different clonal B-cells. The amino acids in each outward-facing TCEM are intercalated with the amino acids of inward-facing MHC groove-exposed motifs (GEM. Different GEM may have differing, allele-specific, MHC binding affinities. The intercalation of TCEM and GEM in a peptide allows for a vast combinatorial repertoire of epitopes, each eliciting a different response. Outcome of T-cell receptor binding is determined by overall signal strength, which is a function of the number of responding T-cells and the duration of engagement. Hence, the frequency of T-cell exposed motif re-use appears to be an important determinant of whether a T-cell response is stimulatory or suppressive. The frequency distribution of TCEMs implies that somatic hypermutation is followed by clonal expansion that develop along repeated pathways. The observations of TCEM and GEM derived from immunoglobulins suggest a relatively simple, yet powerful, mechanism to correlate T-cell polyspecificity, through re-use of TCEMs, with a very high degree of specificity achieved by combination with a diversity of GEMs. The frequency profile of TCEMs also points to an economical mechanism for maintaining T-cell memory, recall, and self-discrimination based on an endogenously generated profile of motifs.

  1. On the low frequency characteristics of head-related transfer function

    Institute of Scientific and Technical Information of China (English)

    XIE Bosun

    2009-01-01

    A method to correct the measured head-related transfer functions (HRTFs) at low frequency was proposed. By analyzing the HRTFs from the spherical head model at low frequency, it is proved that below the frequency of 400 Hz, magnitude of HRTF is nearly constant and the phase is a linear function of frequency both for the far and near field. Therefore, if the HRTFs above 400 Hz are accurately measured by experiment, it is able to correct the HRTFs at low frequency by the theoretical model. The results of calculation and subjective experiment show that the feasibility of the proposed method.

  2. Personality disorder symptoms are differentially related to divorce frequency.

    Science.gov (United States)

    Disney, Krystle L; Weinstein, Yana; Oltmanns, Thomas F

    2012-12-01

    Divorce is associated with a multitude of outcomes related to health and well-being. Data from a representative community sample (N = 1,241) of St. Louis residents (ages 55-64) were used to examine associations between personality pathology and divorce in late midlife. Symptoms of the 10 DSM-IV personality disorders were assessed with the Structured Interview for DSM-IV Personality and the Multisource Assessment of Personality Pathology (both self and informant versions). Multiple regression analyses showed Paranoid and Histrionic personality disorder symptoms to be consistently and positively associated with number of divorces across all three sources of personality assessment. Conversely, Avoidant personality disorder symptoms were negatively associated with number of divorces. The present paper provides new information about the relationship between divorce and personality pathology at a developmental stage that is understudied in both domains.

  3. PEPTIC ULCER FREQUENCY DIFFERENCES RELATED TO H. PYLORI OR AINES

    Directory of Open Access Journals (Sweden)

    Diego Michelon de CARLI

    2015-03-01

    Full Text Available Background Peptic ulcer etiology has been changing because of H. pylori decline. Objectives To estimate peptic ulcer prevalence in 10 years-interval and compare the association with H. pylori and use of non-steroidal anti-inflammatory drugs. Methods Records assessment in two periods: A (1997-2000 and B (2007-2010, searching for peptic ulcer, H. pylori infection and non-steroidal anti-inflammatory drugs use. Results Peptic ulcer occurred in 30.35% in A and in 20.19% in B. H. pylori infection occurred in 73.3% cases in A and in 46.4% in B. Non-steroidal anti-inflammatory drugs use was 3.5% in A and 13.3% in B. Neither condition occurred in 10.4% and 20.5% in A and B respectively. Comparing both periods, we observed reduction of peptic ulcer associated to H. pylori (P=0.000, increase of peptic ulcer related to non-steroidal anti-inflammatory drugs (P=0.000 and idiopathic peptic ulcer (P=0.002. The concurrent association of H. pylori and non-steroidal anti-inflammatory drugs was also higher in B (P=0.002. Rates of gastric ulcer were higher and duodenal ulcer lower in the second period. Conclusions After 10 years, the prevalence of peptic ulcer decreased, as well as ulcers related to H. pylori whereas ulcers associated to non-steroidal anti-inflammatory drugs increased. There was an inversion in the pattern of gastric and duodenal ulcer and a rise of idiopathic peptic ulcer.

  4. Radiation-induced DNA double-strand break frequencies in human squamous cell carcinoma cell lines of different radiation sensitivities

    International Nuclear Information System (INIS)

    DNA neutral (pH 9-6) filter elution was used to measure radiation-induced DNA double-strand break (dsb) frequencies in eight human squamous cell carcinoma cell lines with radiosensitivities (D0) ranging from 1.07 to 2.66 Gy and D-bar values ranging from 1.46 to 4.08 Gy. Elution profiles of unirradiated samples from more radiosensitive cell lines were all steeper in slope than profiles from resistant cells. The shapes of the dsb induction curves were curvilinear and there was some variability from cell line to cell line in the dose-response for the induction of DNA dsb after exposures to 5-100 Gy 60Co γ-rays. There was no relation between shapes of survival curves and shapes of the dose-responses for the induction of DNA dsb. At low doses (5-25 Gy), three out of four of the more sensitive cell lines (D-bar3.0 Gy). Although the low-dose (5-25 Gy) elution results were variable, they suggest that DNA neutral elution will detect differences between sensitive and resistant tumour cells in initial DNA dsb frequencies. (author)

  5. Nanoscale Electric Permittivity of Single Bacterial Cells at Gigahertz Frequencies by Scanning Microwave Microscopy.

    Science.gov (United States)

    Biagi, Maria Chiara; Fabregas, Rene; Gramse, Georg; Van Der Hofstadt, Marc; Juárez, Antonio; Kienberger, Ferry; Fumagalli, Laura; Gomila, Gabriel

    2016-01-26

    We quantified the electric permittivity of single bacterial cells at microwave frequencies and nanoscale spatial resolution by means of near-field scanning microwave microscopy. To this end, calibrated complex admittance images have been obtained at ∼19 GHz and analyzed with a methodology that removes the nonlocal topographic cross-talk contributions and thus provides quantifiable intrinsic dielectric images of the bacterial cells. Results for single Escherichia coli cells provide a relative electric permittivity of ∼4 in dry conditions and ∼20 in humid conditions, with no significant loss contributions. Present findings, together with the ability of microwaves to penetrate the cell membrane, open an important avenue in the microwave label-free imaging of single cells with nanoscale spatial resolution.

  6. Investigation of Frequency of Leftover Drugs at Home and Related Factors

    OpenAIRE

    Muharrem Ucar; Ercan Gocgeldi; Cengiz Han Acikel; Turker Turker; Metin Hasde; Adnan Atac

    2009-01-01

    AIM: The purpose of this survey was to investigate the frequency of leftover drugs at homes and related factors regarding this problem. METHOD: This descriptive study was performed among 692 non-medical personnel servicing at two military bases in December 2006. Data were collected by using a questionnaire, which had been developed by the investigators. Frequencies and percents were used as descriptive statistics. Chi-square test was used to compare the frequencies of leftover drugs according...

  7. Frequency-Tunable Microwave Field Detection in an Atomic Vapor Cell

    CERN Document Server

    Horsley, Andrew

    2016-01-01

    We use an atomic vapor cell as a frequency tunable microwave field detector operating at frequencies from GHz to tens of GHz. We detect microwave magnetic fields from 2.3 GHz to 26.4 GHz, and measure the amplitude of the sigma+ component of an 18 GHz microwave field. Our proof-of-principle demonstration represents a four orders of magnitude extension of the frequency tunable range of atomic magnetometers from their previous dc to several MHz range. When integrated with a high resolution microwave imaging system, this will allow for the complete reconstruction of the vector components of a microwave magnetic field and the relative phase between them. Potential applications include near-field characterisation of microwave circuitry and devices, and medical microwave sensing and imaging.

  8. FINDbase: A relational database recording frequencies of genetic defects leading to inherited disorders worldwide

    NARCIS (Netherlands)

    S. van Baal (Sjozef); P. Kaimakis (Polynikis); M. Phommarinh (Manyphong); D. Koumbi (Daphne); H. Cuppens (Harry); F. Riccardino (Francesca); M. Macek (Milan MI); C.R. Scriver (Charles); G.P. Patrinos (George)

    2007-01-01

    textabstractFrequency of INherited Disorders database (FINDbase) (http://www.findbase.org) is a relational database, derived from the ETHNOS software, recording frequencies of causative mutations leading to inherited disorders worldwide. Database records include the population and ethnic group, the

  9. [Change of cholinesterase relative activity under modulated ultra high frequency electromagnetic radiation in experiments in vitro].

    Science.gov (United States)

    Pashovkina, M S; Pashovkin, T N

    2011-01-01

    Changes in the activity of enzyme cholinesterase (ChE) have been experimentally investigated under the influence of amplitude-modulated super-high-frequency electromagnetic radiation (carrier frequency of 2.375 MHz; power flux density of 8 mW/cm2, 20 mW/cm2 and 50 mW/cm2; modulation frequency range 10 to 210 Hz; exposure time 5 min). The appearance of peaks of the cholinesterase increased relative activity, as well as the changes in the direction and intensity of the reaction associated with the modulation frequency and power flux are observed at equal power flux densities and exposure times.

  10. Timescales and Frequencies of Reversible and Irreversible Adhesion Events of Single Bacterial Cells.

    Science.gov (United States)

    Hoffman, Michelle D; Zucker, Lauren I; Brown, Pamela J B; Kysela, David T; Brun, Yves V; Jacobson, Stephen C

    2015-12-15

    In the environment, most bacteria form surface-attached cell communities called biofilms. The attachment of single cells to surfaces involves an initial reversible stage typically mediated by surface structures such as flagella and pili, followed by a permanent adhesion stage usually mediated by polysaccharide adhesives. Here, we determine the absolute and relative timescales and frequencies of reversible and irreversible adhesion of single cells of the bacterium Caulobacter crescentus to a glass surface in a microfluidic device. We used fluorescence microscopy of C. crescentus expressing green fluorescent protein to track the swimming behavior of individual cells prior to adhesion, monitor the cell at the surface, and determine whether the cell reversibly or irreversibly adhered to the surface. A fluorescently labeled lectin that binds specifically to polar polysaccharides, termed holdfast, discriminated irreversible adhesion events from reversible adhesion events where no holdfast formed. In wild-type cells, the holdfast production time for irreversible adhesion events initiated by surface contact (23 s) was 30-times faster than the holdfast production time that occurs through developmental regulation (13 min). Irreversible adhesion events in wild-type cells (3.3 events/min) are 15-times more frequent than in pilus-minus mutant cells (0.2 events/min), indicating the pili are critical structures in the transition from reversible to irreversible surface-stimulated adhesion. In reversible adhesion events, the dwell time of cells at the surface before departing was the same for wild-type cells (12 s) and pilus-minus mutant cells (13 s), suggesting the pili do not play a significant role in reversible adhesion. Moreover, reversible adhesion events in wild-type cells (6.8 events/min) occur twice as frequently as irreversible adhesion events (3.3 events/min), demonstrating that most cells contact the surface multiple times before transitioning from reversible to

  11. Precipitation-Frequency and Discharge-Frequency Relations for Basins Less than 32 Square Miles in Kansas

    Science.gov (United States)

    Perry, Charles A.

    2008-01-01

    Precipitation-frequency and discharge-frequency relations for small drainage basins with areas less than 32 square miles in Kansas were evaluated to reduce the uncertainty of discharge-frequency estimates. Gaged-discharge records were used to develop discharge-frequency equations for the ratio of discharge to drainage area (Q/A) values using data from basins with variable soil permeability, channel slope, and mean annual precipitation. Soil permeability and mean annual precipitation are the dominant basin characteristics in the multiple linear regression analyses. In addition, 28 discharge measurements at ungaged sites by indirect surveying methods and by velocity meters also were used in this analysis to relate precipitation-recurrence interval to discharge-recurrence interval. Precipitation-recurrence interval for each of these discharge measurements were estimated from weather-radar estimates of precipitation and from nearby raingages. Time of concentration for each basin for each of the ungaged sites was computed and used to determine the precipitation-recurrence interval based on precipitation depth and duration. The ratio of discharge/drainage area (Q/A) value for each event was then assigned to that precipitation-recurrence interval. The relation between the ratio of discharge/drainage area (Q/A) and precipitation-recurrence interval for all 28 measured events resulted in a correlation coefficient of 0.79. Using basins less than 5.4 mi2 only, the correlation decreases to 0.74. However, when basins greater than 5.4 and less than 32 mi2 are examined the relation improves to a correlation coefficient of 0.95. There were a sufficient number of discharge and radar-measured precipitation events for both the 5-year (8 events) and the 100-year (11 events) recurrence intervals to examine the effect of basin characteristics on the Q/A values for basins less than 32 mi2. At the 5-year precipitation-/discharge-recurrence interval, channel slope was a significant

  12. Frequency dependent capacitance studies of the CdS/Cu/sub 2/S thin-film solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Hmurcik, L.V.; Serway, R.A.

    1982-05-01

    Measurements of the dark capacitance of CdS cells as a function of the frequency of the applied signal voltage have shown that the capacitance varies with frequency according to the relation C-C/sub infinity/ = (C/sub 0/-C/sub infinity/)/(1+..omega../sup 2/tau/sup 2/), where tau is the time constant associated with interfacial and deep bulk states. Photocapacitance studies show that the CdS cell can be treated according to the frequency dependent model of Schibli and Milnes. Under the influence of light, Capprox.1/(..omega..)/sup 1/2/. Further work demonstrates that the simple planar junction model most often used to describe the CdS cell is accurate at high frequencies.

  13. Extremely Low Frequency Magnetic Fields Induce Spermatogenic Germ Cell Apoptosis: Possible Mechanism

    Directory of Open Access Journals (Sweden)

    Sang-Kon Lee

    2014-01-01

    Full Text Available The energy generated by an extremely low frequency electromagnetic field (ELF-EMF is too weak to directly induce genotoxicity. However, it is reported that an extremely low frequency magnetic field (ELF-MF is related to DNA strand breakage and apoptosis. The testes that conduct spermatogenesis through a dynamic cellular process involving meiosis and mitosis seem vulnerable to external stress such as heat, MF exposure, and chemical or physical agents. Nevertheless the results regarding adverse effects of ELF-EMF on human or animal reproductive functions are inconclusive. According to the guideline of the International Commission on Non-Ionizing Radiation Protection (ICNIRP; 2010 for limiting exposure to time-varying MF (1 Hz to 100 kHz, overall conclusion of epidemiologic studies has not consistently shown an association between human adverse reproductive outcomes and maternal or paternal exposure to low frequency fields. In animal studies there is no compelling evidence of causal relationship between prenatal development and ELF-MF exposure. However there is increasing evidence that EL-EMF exposure is involved with germ cell apoptosis in testes. Biophysical mechanism by which ELF-MF induces germ cell apoptosis has not been established. This review proposes the possible mechanism of germ cell apoptosis in testes induced by ELF-MF.

  14. Density and relative frequency effects on competitive interactions and resource use in pea–barley intercrops

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, H.; Andersen, H.K.; Jørnsgaard, B.;

    2006-01-01

    Intercropping advantages may be influenced by both plant density and relative frequency of the intercrop components. In a field study barley (Hordeum vulgare L.) and pea (Pisum sativum L.) were sole cropped and intercropped at three densities and with two relative frequencies when intercropped....... Earlier seedling emergence gave barley an initial growth advantage, assessed using the relative efficiency index (REIc), whereas pea was in general more growth efficient once the initial growth phase had been passed. This reversal in relative growth efficiency along with the observation that early barley...... not increase its reliance on atmospheric nitrogen fixation compared to the pea sole crop. With respect to soil nitrogen uptake there were no effect of plant density but a strong effect of the relative frequency of pea in the intercrop, the greater the proportion the lower the uptake. Changes in the competitive...

  15. Frequency of Early and Late Chromosome Aberrations in Different Types of Cells After Proton and Fe Ion Irradiation

    Science.gov (United States)

    Lu, Tao; Zhang, Ye; Yeshitla, Samrawit; Bowler, Deborah; Kadhim, Munira; Wilson, Bobby; Wu, Honglu

    2016-01-01

    DNA damages induced by space radiation, consisting of protons and high-LET charged particles, can be complex in nature, which are often left unrepaired and cause chromosomal aberrations. Increased level of genomic instability is attributed to tumorigenesis and increased cancer risks. To investigate genomic instability induced by charged particles, human lymphocytes ex vivo, human fibroblasts, and human mammary epithelial cells, as well as mouse bone marrow stem cells isolated from CBA/CaH and C57BL/6 strains were exposed to high energy protons and Fe ions. Metaphase chromosome spreads at different cell divisions after radiation exposure were collected and, chromosome aberrations were analyzed with fluorescence in situ hybridization with whole chromosome-specific probes for human cells. With proton irradiation, levels of chromosome aberrations decreased by about 50% in both lymphocytes and epithelial cells after multiple cell divisions, compared to initial chromosome aberrations at 48 hours post irradiation in both cell types. With Fe ion irradiation, however, the frequency of chromosome aberrations in lymphocytes after multiple cell divisions was significantly lower than that in epithelial cells at comparable cell divisions, while their initial chromosome aberrations were at similar levels. Similar to the human cells, after Fe ion irradiation, the frequency of late chromosome aberrations was similar to that of the early damages for radio-sensitive CBA cells, but different for radio-resistant C57 cells. Our results suggest that relative biological effectiveness (RBE) values are dependent not only on radiation sources, but also on cell types and cell divisions.

  16. Frequency of Early and Late Chromosome Aberrations in Different Types of Cells After Proton and Fe Ion Irradiation

    Science.gov (United States)

    Lu, Tao; Wu, Honglu; Zhang, Ye; Yeshitla, Samrawit; Kadhim, Munira; Wilson, Bobby; Bowler, Deborah

    2016-07-01

    DNA damages induced by space radiation, consisting of protons and high-LET charged particles, can be complex in nature, which are often left unrepaired and cause chromosomal aberrations. Increased level of genomic instability is attributed to tumorigenesis and increased cancer risks. To investigate genomic instability induced by charged particles, human lymphocytes ex vivo, human fibroblasts, and human mammary epithelial cells, as well as mouse bone marrow stem cells isolated from CBA/CaH and C57BL/6 strains were exposed to high energy protons and Fe ions. Metaphase chromosome spreads at different cell divisions after radiation exposure were collected and, chromosome aberrations were analyzed with fluorescence in situ hybridization with whole chromosome-specific probes for human cells. With proton irradiation, levels of chromosome aberrations decreased by about 50% in both lymphocytes and epithelial cells after multiple cell divisions, compared to initial chromosome aberrations at 48 hours post irradiation in both cell types. With Fe ion irradiation, however, the frequency of chromosome aberrations in lymphocytes after multiple cell divisions was significantly lower than that in epithelial cells at comparable cell divisions, while their initial chromosome aberrations were at similar levels. Similar to the human cells, after Fe ion irradiation, the frequency of late chromosome aberrations was similar to that of the early damages for radio-sensitive CBA cells, but different for radio-resistant C57 cells. Our results suggest that relative biological effectiveness (RBE) values are dependent not only on radiation sources, but also on cell types and cell divisions.

  17. HIV-Infected Children Have Lower Frequencies of CD8+ Mucosal-Associated Invariant T (MAIT) Cells that Correlate with Innate, Th17 and Th22 Cell Subsets.

    Science.gov (United States)

    Khaitan, Alka; Kilberg, Max; Kravietz, Adam; Ilmet, Tiina; Tastan, Cihan; Mwamzuka, Mussa; Marshed, Fatma; Liu, Mengling; Ahmed, Aabid; Borkowsky, William; Unutmaz, Derya

    2016-01-01

    Mucosal-associated invariant T cells (MAIT) are innate T cells restricted by major histocompatibility related molecule 1 (MR1) presenting riboflavin metabolite ligands derived from microbes. Specificity to riboflavin metabolites confers MAIT cells a broad array of host-protective activity against gram-negative and -positive bacteria, mycobacteria, and fungal pathogens. MAIT cells are present at low levels in the peripheral blood of neonates and gradually expand to relatively abundant levels during childhood. Despite no anti-viral activity, MAIT cells are depleted early and irreversibly in HIV infected adults. Such loss or impaired expansion of MAIT cells in HIV-positive children may render them more susceptible to common childhood illnesses and opportunistic infections. In this study we evaluated the frequency of MAIT cells in perinatally HIV-infected children, their response to antiretroviral treatment and their associations with HIV clinical status and related innate and adaptive immune cell subsets with potent antibacterial effector functions. We found HIV+ children between ages 3 to 18 years have significantly decreased CD8+ MAIT cell frequencies compared to uninfected healthy children. Remarkably, CD8 MAIT levels gradually increased with antiretroviral therapy, with greater recovery when treatment is initiated at a young age. Moreover, diminished CD8+ MAIT cell frequencies are associated with low CD4:CD8 ratios and elevated sCD14, suggesting a link with HIV disease progression. Last, CD8+ MAIT cell levels tightly correlate with other antibacterial and mucosa-protective immune subsets, namely, neutrophils, innate-like T cells, and Th17 and Th22 cells. Together these findings suggest that low frequencies of MAIT cells in HIV positive children are part of a concerted disruption to the innate and adaptive immune compartments specialized in sensing and responding to pathogenic or commensal bacteria. PMID:27560150

  18. Time-Frequency Data Reduction for Event Related Potentials: Combining Principal Component Analysis and Matching Pursuit

    Directory of Open Access Journals (Sweden)

    Selin Aviyente

    2010-01-01

    Full Text Available Joint time-frequency representations offer a rich representation of event related potentials (ERPs that cannot be obtained through individual time or frequency domain analysis. This representation, however, comes at the expense of increased data volume and the difficulty of interpreting the resulting representations. Therefore, methods that can reduce the large amount of time-frequency data to experimentally relevant components are essential. In this paper, we present a method that reduces the large volume of ERP time-frequency data into a few significant time-frequency parameters. The proposed method is based on applying the widely used matching pursuit (MP approach, with a Gabor dictionary, to principal components extracted from the time-frequency domain. The proposed PCA-Gabor decomposition is compared with other time-frequency data reduction methods such as the time-frequency PCA approach alone and standard matching pursuit methods using a Gabor dictionary for both simulated and biological data. The results show that the proposed PCA-Gabor approach performs better than either the PCA alone or the standard MP data reduction methods, by using the smallest amount of ERP data variance to produce the strongest statistical separation between experimental conditions.

  19. Effect of Discourse Context and Modifier Relation Frequency on Conceptual Combination

    Science.gov (United States)

    Gagne, Christina L.; Spalding, Thomas L.

    2004-01-01

    The present experiments investigate the influence of modifier relation frequency and discourse context on the interpretation of novel noun-noun phrases (as measured by both the ease of interpretation and the types of interpretations that are provided). We assess whether people access knowledge about the relations with which the modifier is…

  20. THE RELATION BETWEEN MAGNITUDE AND FREQUENCY IN ROCKBURST AND ITS APPLICATION IN FORECASTIONG

    Institute of Scientific and Technical Information of China (English)

    潘一山; 刘建军; 仲玉; 徐方军; 徐秉业; 关杰

    1998-01-01

    The rockburst data of Huafeng and Da'anshan Mine were analysised in this paper. From the statistical results, we know that the relation between magnitude and frequency in rockburst is linear. Using this relation, the maximum magnitude and tendency of rockburst can be predicted.The theory can improve the quantitive prediction level in rockburst.

  1. On the applicability of Kramers-Kronig relations for ultrasonic attenuation obeying a frequency power law

    Science.gov (United States)

    Waters; Hughes; Mobley; Brandenburger; Miller

    2000-08-01

    In the recent literature concern has been raised regarding the validity of Kramers-Kronig relations for media with ultrasonic attenuation obeying a frequency power law. It is demonstrated, however, that the Kramers-Kronig dispersion relations for application to these types of media are available. The developed dispersion relations are compared with measurements on several liquids, and agreement is found to better than 1 m/s over the experimentally available bandwidth. A discussion regarding the validity of these dispersion relations, in particular how the dispersion relations relate to the so-called Paley-Wiener conditions, forms the conclusion.

  2. Frequency-domain generelaized singular peruturbation method for relative error model order reduction

    Institute of Scientific and Technical Information of China (English)

    Hamid Reza SHAKER

    2009-01-01

    A new mixed method for relative error model order reduction is proposed.In the proposed method the frequency domain balanced stochastic truncation method is improved by applying the generalized singular perturbation method to the frequency domain balanced system in the reduction procedure.The frequency domain balanced stochastic truncation method,which was proposed in [15] and [17] by the author,is based on two recently developed methods,namely frequency domain balanced truncation within a desired frequency bound and inner-outer factorization techniques.The proposed method in this paper is a carry over of the frequency-domain balanced stochastic truncation and is of interest for practical model order reduction because in this context it shows to keep the accuracy of the approximation as high as possible without sacrificing the computational efficiency and important system properties.It is shown that some important properties of the frequency domain stochastic balanced reduction technique are extended to the proposed reduction method by using the concept and properties of the reciprocal systems.Numerical results show the accuracy,simplicity and flexibility enhancement of the method.

  3. An inverse relation between event-related and time-frequency violation responses in sentence processing.

    Science.gov (United States)

    Davidson, D J; Indefrey, P

    2007-07-16

    The relationship between semantic and grammatical processing in sentence comprehension was investigated by examining event-related potential (ERP) and event-related power changes in response to semantic and grammatical violations. Sentences with semantic, phrase structure, or number violations and matched controls were presented serially (1.25 words/s) to 20 participants while EEG was recorded. Semantic violations were associated with an N400 effect and a theta band increase in power, while grammatical violations were associated with a P600 effect and an alpha/beta band decrease in power. A quartile analysis showed that for both types of violations, larger average violation effects were associated with lower relative amplitudes of oscillatory activity, implying an inverse relation between ERP amplitude and event-related power magnitude change in sentence processing.

  4. Quantification of event-related desynchronization/synchronization at low frequencies in a semantic memory task.

    Science.gov (United States)

    Gómez, Juan; Aguilar, Mónica; Horna, Eduardo; Minguez, Javier

    2012-01-01

    Although several techniques have been developed for the visualization of EEG event-related desynchronization/synchronization (ERD/ERS) in both time and frequency domains, none of the quantification methods takes advantage of the time and frequency resolution at the same time. Existing techniques for the quantification of the ERD/ERS changes compute the average EEG power increase/decrease relative to certain reference value, over fixed time intervals and/or frequency bands (either fixed or individualized). Inaccuracy in the computation of these frequency bands (where the process is actually measured) in combination with the averaging process over time may lead to errors in the computation of any ERD/ERS quantification parameter. In this paper, we present a novel method for the automatic, individual and exact quantification of the most significant ERD/ERS region within a given window of the time-frequency domain. The method is exemplified by quantifying the ERS at low frequencies of 10 subjects performing a semantic memory task, and compared with existing techniques. PMID:23366438

  5. Statistical significance of task related deep brain EEG dynamic changes in the time-frequency domain.

    Science.gov (United States)

    Chládek, J; Brázdil, M; Halámek, J; Plešinger, F; Jurák, P

    2013-01-01

    We present an off-line analysis procedure for exploring brain activity recorded from intra-cerebral electroencephalographic data (SEEG). The objective is to determine the statistical differences between different types of stimulations in the time-frequency domain. The procedure is based on computing relative signal power change and subsequent statistical analysis. An example of characteristic statistically significant event-related de/synchronization (ERD/ERS) detected across different frequency bands following different oddball stimuli is presented. The method is used for off-line functional classification of different brain areas. PMID:24109865

  6. Evaluation of disease frequency in the first line relatives of patients suffering from schizophrenia related to gender and diagnostic categories

    Directory of Open Access Journals (Sweden)

    Sulejmanpašić-Arslanagić Gorana

    2013-01-01

    Full Text Available Introduction. Schizophrenia represents the most severe mental disorder. The aim of this study was to determine the frequency of disease in the first line relatives of patients suffering from schizophrenia related to gender differences and various subtypes. Material and Methods. The study included 453 subjects (121 patients suffering from schizophrenia - 52.1% males and 47.9% females and 332 first line relatives of the patients - 47.2% males and 52.7% females during a five year period, mostly in the region of Sarajevo. Results. According to the analysis of disease frequency related to the kinship, the disease developed more frequently in mothers (8.3% and sisters (7.8% than in fathers (6.9 and brothers (7.1% of the patients suffering from paranoid schizophrenia. In the group of disorganized schizophrenia, only mothers were found (4.2%, whereas the statistical difference in the group of affected brothers and sisters was significant, the percentage being 9.7% and 15.3%, respectively. There was a statistically significant difference in gender (p<0.05 between the group of parents and siblings regarding the frequency of schizophrenia. Discussion. The proof of participation of genetic factors in etiology supports the assumption on genetic nature of familial aggregation of schizophrenia. Our results completely match those of studies which analyzed the frequency of disease regarding inheritance (gender distribution and various subtypes. Conclusion. Investigation points to the common epidemiological criteria regarding the frequency of schizophrenic psychosis. Genetic predisposition could be also a demonstrator of the disease course and outcome, which should enable better understanding of the etiology of this disease.

  7. Comparison between power-law rheological parameters of living cells in frequency and time domains measured by atomic force microscopy

    Science.gov (United States)

    Takahashi, Ryosuke; Okajima, Takaharu

    2016-08-01

    We investigated how stress relaxation mapping is quantified compared with the force modulation mapping of confluent epithelial cells using atomic force microscopy (AFM). Using a multi-frequency AFM technique, we estimated the power-law rheological behaviors of cells simultaneously in time and frequency domains. When the power-law exponent α was low ( 0.1), α in the time domain was underestimated relative to that in the frequency domain, and the difference increased with α, whereas the cell modulus was overestimated in the time domain. These results indicate that power-law rheological parameters estimated by stress relaxation are sensitive to lag time during initial indentation, which is inevitable in time-domain AFM experiments.

  8. Individual Differences in the Frequency-Following Response: Relation to Pitch Perception.

    Directory of Open Access Journals (Sweden)

    Emily B J Coffey

    Full Text Available The scalp-recorded frequency-following response (FFR is a measure of the auditory nervous system's representation of periodic sound, and may serve as a marker of training-related enhancements, behavioural deficits, and clinical conditions. However, FFRs of healthy normal subjects show considerable variability that remains unexplained. We investigated whether the FFR representation of the frequency content of a complex tone is related to the perception of the pitch of the fundamental frequency. The strength of the fundamental frequency in the FFR of 39 people with normal hearing was assessed when they listened to complex tones that either included or lacked energy at the fundamental frequency. We found that the strength of the fundamental representation of the missing fundamental tone complex correlated significantly with people's general tendency to perceive the pitch of the tone as either matching the frequency of the spectral components that were present, or that of the missing fundamental. Although at a group level the fundamental representation in the FFR did not appear to be affected by the presence or absence of energy at the same frequency in the stimulus, the two conditions were statistically distinguishable for some subjects individually, indicating that the neural representation is not linearly dependent on the stimulus content. In a second experiment using a within-subjects paradigm, we showed that subjects can learn to reversibly select between either fundamental or spectral perception, and that this is accompanied both by changes to the fundamental representation in the FFR and to cortical-based gamma activity. These results suggest that both fundamental and spectral representations coexist, and are available for later auditory processing stages, the requirements of which may also influence their relative strength and thus modulate FFR variability. The data also highlight voluntary mode perception as a new paradigm with which to

  9. The changes of frequencies of regulatory T cells in peripheral blood and serum levels of IL-1β ,IL-6 and IL-10 in patients with HBV-related liver cirrhosis%乙型肝炎肝硬化患者外周血调节性T细胞频率及血清IL-1β、IL-6和IL-10水平的变化

    Institute of Scientific and Technical Information of China (English)

    李晨; 邢少军; 段学章; 胡瑾华; 柳芳芳; 王慧芬; 万谟彬

    2012-01-01

    目的 检测未抗病毒治疗的乙型肝炎肝硬化患者外周血调节性T细胞(Treg细胞)及其亚群频率和血清IL.1 β、IL-6、IL-10水平,以探讨乙型肝炎肝硬化患者免疫功能的变化.方法 在20例健康对照人群、17例慢性乙型肝炎(CHB)患者和38例乙型肝炎肝硬化(LC)患者,采用流式细胞仪检测外周血CD4+CD25+Foxp3+(Treg)细胞频率、CD4+CD39+Foxp3+(CD39+Freg)细胞和CD4+CTLA-4+Foxp3+(CTLA-4+Freg)细胞频率;采用ELISA法检测血清IL-1β、IL-6和IL-10水平.结果 LC患者Treg细胞频率、CD39+Treg细胞频率、CTLA-4+Treg细胞频率、血清IL-1β、IL-6和IL-10水平均高于正常人(P均<0.01)和CHB患者(P<0.05或P<0.01);失代偿期LC患者Treg细胞频率、CD39+Treg细胞频率、IL-6水平高于代偿期患者(P均<0.01);LC患者Treg细胞频率与CD39+Treg细胞频率(r=0.474,P<0.01)、CTLA-4+Treg细胞频率均呈正相关(r=0.330,P<0.05),Treg细胞频率(r=0.381,P<0.05)、CD39+Treg细胞频率(r=0.333,P<0.05)与TBil呈正相关.Treg细胞频率(r=-0.549,P<0.01)、CD39+Treg细胞频率(r=-0.437,P<0.01)、CTLA-4+Treg细胞频率(r=-0.368,P<0.01)与PTA呈负相关,CD39+Treg细胞频率与AST呈正相关(r=0.406,P<0.05).结论 Treg细胞及其亚群频率和IL-1β、IL-6、IL-10水平的变化可作为临床初始治疗的乙型肝炎肝硬化患者辅助检查指标之一.%Objective To investigate the frequencies of regulatory T cells (Treg cells), its subgroups and serum levels of IL-1 B ,IL-6 and IL-10 in HBV-related liver cirrhosis. Methods In 20 healthy persons, 17 patients with chronic hepatitis B (CHB) and 38 with HBV-related liver cirrhosis (LC),the frequencies of CD4+ CD25+Fox3+ cells (Treg cells ),CD4+CD39+Fox3+cells(CD394Treg cells),and CD4+CTLA-4+ Fox3+cells(CTLA-4+ Treg cells) were detected by flow cytometry. The serum levels of IL-1 B , IL-6 and IL-10 were detected by ELISA. Results The frequencies of Treg cells,CD39+ Treg cells and CTLA-4Treg cells and the serum levels of IL

  10. Selective attention modulates human auditory brainstem responses: relative contributions of frequency and spatial cues.

    Directory of Open Access Journals (Sweden)

    Alexandre Lehmann

    Full Text Available Selective attention is the mechanism that allows focusing one's attention on a particular stimulus while filtering out a range of other stimuli, for instance, on a single conversation in a noisy room. Attending to one sound source rather than another changes activity in the human auditory cortex, but it is unclear whether attention to different acoustic features, such as voice pitch and speaker location, modulates subcortical activity. Studies using a dichotic listening paradigm indicated that auditory brainstem processing may be modulated by the direction of attention. We investigated whether endogenous selective attention to one of two speech signals affects amplitude and phase locking in auditory brainstem responses when the signals were either discriminable by frequency content alone, or by frequency content and spatial location. Frequency-following responses to the speech sounds were significantly modulated in both conditions. The modulation was specific to the task-relevant frequency band. The effect was stronger when both frequency and spatial information were available. Patterns of response were variable between participants, and were correlated with psychophysical discriminability of the stimuli, suggesting that the modulation was biologically relevant. Our results demonstrate that auditory brainstem responses are susceptible to efferent modulation related to behavioral goals. Furthermore they suggest that mechanisms of selective attention actively shape activity at early subcortical processing stages according to task relevance and based on frequency and spatial cues.

  11. The Homework-Achievement Relation Reconsidered: Differentiating Homework Time, Homework Frequency, and Homework Effort

    Science.gov (United States)

    Trautwein, Ulrich

    2007-01-01

    The popular claim that homework time is positively related to achievement and achievement gains was tested in three studies. Time on homework was compared and contrasted with other indicators of homework assignment (i.e., homework frequency) and students' homework behavior (i.e., homework effort). The results of the three studies indicate that…

  12. Frequency of Repeated Courses Its Relation to Persistence and Performance in Lebanon's Higher Education

    Science.gov (United States)

    Nasser, Ramzi; Nauffal, Diane

    2012-01-01

    This study assesses the relationship between the frequency of repeating courses and students' performance in college. The study uses cohort data from academic years 2000/2001, 2001/2002, 2002/2003 and 2003/2004. We compared those who had repeated one, two and three courses on GPA and whether a relation exists of those who graduated/did not…

  13. Parental work demands and the frequency of child-related routine and interactive activities

    NARCIS (Netherlands)

    Roeters, A.; Lippe, T. van der; Kluwer, E.

    2009-01-01

    This study examined whether the frequency of child-related activities was associated with parents’ own work demands and those of their partners. In addition to parental paid working hours, we considered the parents’ organizational culture and experienced job insecurity. Moreover, we differentiated b

  14. Association of the frequency of peripheral natural killer T cells with nonalcoholic fatty liver disease

    Institute of Scientific and Technical Information of China (English)

    Cheng-Fu Xu; Chao-Hui Yu; You-Ming Li; Lei Xu; Juan Du; Zhe Shen

    2007-01-01

    AIM: To investigate whether changes in the frequency of peripheral natural killer T (NKT) cells were correlated with liver disease in patients who had metabolic predispositions to nonalcoholic fatty liver disease (NAFLD).METHODS: Peripheral blood samples were obtained from 60 Chinese NAFLD patients and 60 age and gender matched healthy controls. The frequency of peripheral NKT cells was detected by flow cytometry. Clinical and laboratory data were collected for further analysis.RESULTS: NAFLD patients had a lower frequency of peripheral NKT cells than healthy controls (1.21% ± 0.06% vs 1.62% ± 0.07%, P < 0.001). Further analysis revealed that the frequency of peripheral NKT cells was negatively correlated with body mass index, waist circumference and serum levels of alanine aminotransferase. Logistic regression analysis revealed that elevated body mass index [hazard ratio (HR):2.991], aspartate aminotransferase levels (HR: 1.148)and fasting blood sugar (HR: 3.133) increased the risk of NAFLD, whereas an elevated frequency of peripheral NKT cells (HR: 0.107) decreased the risk.CONCLUSION: Changes in the frequency of peripheral NKT cells were correlated with NAFLD and a decreased frequency of peripheral NKT cells was a risk factor for NAFLD.

  15. Explaining the relative frequency of face to face meetings in cooperative relationships between companies

    OpenAIRE

    Aguilera, Anne; Lethiais, Virginie

    2015-01-01

    This paper analyses the factors that influence the relative frequency of face-to-face meetings when companies cooperate with each other. Specifically, we explore the role of geographical distance between the partners and how it affects the influence of other factors, especially the nature of knowledge and the ability to use information technology. An econometric analysis based on a survey of 338 companies in the Brittany region (France) shows that the factors that influence the relative frequ...

  16. Modulation of Osteogenesis in MC3T3-E1 Cells by Different Frequency Electrical Stimulation.

    Directory of Open Access Journals (Sweden)

    Yu Wang

    Full Text Available Electrical stimulation (ES is therapeutic to many bone diseases, from promoting fracture regeneration to orthopedic intervention. The application of ES offers substantial therapeutic potential, while optimal ES parameters and the underlying mechanisms responsible for the positive clinical impact are poorly understood. In this study, we assembled an ES cell culture and monitoring device. Mc-3T3-E1 cells were subjected to different frequency to investigate the effect of osteogenesis. Cell proliferation, DNA synthesis, the mRNA levels of osteosis-related genes, the activity of alkaline phosphatase (ALP, and intracellular concentration of Ca2+ were thoroughly evaluated. We found that 100 Hz could up-regulate the mRNA levels of collagen I, collagen II and Runx2. On the contrary, ES could down-regulate the mRNA levels of osteopontin (OPN. ALP activity assay and Fast Blue RR salt stain showed that 100 Hz could accelerate cells differentiation. Compared to the control group, 100 Hz could promote cell proliferation. Furthermore, 1 Hz to 10 Hz could improve calcium deposition in the intracellular matrix. Overall, these results indicate that 100Hz ES exhibits superior potentialities in osteogenesis, which should be beneficial for the clinical applications of ES for the treatment of bone diseases.

  17. A microdroplet cell culture based high frequency somatic embryogenesis system for pigeonpea, Cajanus cajan (L.) Millsp.

    Science.gov (United States)

    Kumar, Nagan Udhaya; Gnanaraj, Muniraj; Sindhujaa, Vajravel; Viji, Maluventhen; Manoharan, Kumariah

    2015-09-01

    A protocol for high frequency production of somatic embryos was worked out in pigeonpea, Cajanus cajan (L.) Millsp. The protocol involved sequential employment of embryogenic callus cultures, low density cell suspension cultures and a novel microdroplet cell culture system. The microdroplet cell cultures involved culture of a single cell in 10 μI of Murashige and Skoog's medium supplemented with phytohormones, growth factors and phospholipid precursors. By employing the microdroplet cell cultures, single cells in isolation were grown into cell clones which developed somatic embryos. Further, 2,4-dichlorophenoxyacetic acid, kinetin, polyethylene glycol, putrescine, spermine, spermidine, choline chloride, ethanolamine and LiCl were supplemented to the low density cell suspension cultures and microdroplet cell cultures to screen for their cell division and somatic embryogenesis activity. Incubation of callus or the inoculum employed for low density cell suspension cultures and microdroplet cell cultures with polyethylene glycol was found critical for induction of somatic embryogenesis. Somatic embryogenesis at a frequency of 1.19, 3.16 and 6.51 per 10(6) cells was achieved in the callus, low density cell suspension cultures and microdroplet cell cultures, respectively. Advantages of employing microdroplet cell cultures for high frequency production of somatic embryos and its application in genetic transformation protocols are discussed. PMID:26548080

  18. Study on correlativity among some seismological prediction indexes related to earthquake frequency or energy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Correlation among various seismological prediction indexes related to earthquake frequency N or energy E for describing seismicity changes is studied by seismic data of 11 seismic zones (areas) in the Sichuan-Yunnan region. A statistical test for correlativity shows that seismicity indexes obtained from transformation of earthquake fre-quency N or energy E have correlation to a certain extent while they are used to describe seismicity changes. If the transformation is linear in all cases, the correlation coefficient is equal to 1. The smaller the transformation devia-tion from linearity, the bigger the correlation coefficient is.

  19. Relative frequencies of seismic main shocks after strong shocks in Italy

    Science.gov (United States)

    Gasperini, Paolo; Lolli, Barbara; Vannucci, Gianfranco

    2016-07-01

    We analyzed a catalog of Italian earthquakes, covering 55 years of data from 1960 to 2014 with magnitudes homogeneously converted to Mw, to compute the time-dependent relative frequencies with which strong seismic shocks (4.0≤Mwearthquakes (with Mw≥6.0) mainly occurred within two or three months of the strong shock. The frequency gains vary from about 10000 for very short time intervals to less than 10 for a time interval of two years. Only about one-third of main shocks were preceded by at least a strong shock in the previous day and about one-half in the previous month.

  20. Influence on cell death of high frequency motion of magnetic nanoparticles during magnetic hyperthermia experiments

    Science.gov (United States)

    Hallali, N.; Clerc, P.; Fourmy, D.; Gigoux, V.; Carrey, J.

    2016-07-01

    Studies with transplanted tumors in animals and clinical trials have provided the proof-of-concept of magnetic hyperthermia (MH) therapy of cancers using iron oxide nanoparticles. Interestingly, in several studies, the application of an alternating magnetic field (AMF) to tumor cells having internalized and accumulated magnetic nanoparticles (MNPs) into their lysosomes can induce cell death without detectable temperature increase. To explain these results, among other hypotheses, it was proposed that cell death could be due to the high-frequency translational motion of MNPs under the influence of the AMF gradient generated involuntarily by most inductors. Such mechanical actions of MNPs might cause cellular damages and participate in the induction of cell death under MH conditions. To test this hypothesis, we developed a setup maximizing this effect. It is composed of an anti-Helmholtz coil and two permanent magnets, which produce an AMF gradient and a superimposed static MF. We have measured the MNP heating power and treated tumor cells by a standard AMF and by an AMF gradient, on which was added or not a static magnetic field. We showed that the presence of a static magnetic field prevents MNP heating and cell death in standard MH conditions. The heating power of MNPs in an AMF gradient is weak, position-dependent, and related to the presence of a non-zero AMF. Under an AMF gradient and a static field, no MNP heating and cell death were measured. Consequently, the hypothesis that translational motions could be involved in cell death during MH experiments is ruled out by our experiments.

  1. Testing frequencies of safety related pumps and valves: Probabilistic safety assessment versus United States industry codes

    International Nuclear Information System (INIS)

    PSA provides a mechanism for identifying key risk significant components and estimating the effects of test frequency changes. If it is possible to optimize the testing frequencies of these components, component failure probabilities can be minimized. This reduces overall system unavailability and the probability of core damage. In cases where test frequencies cannot be adjusted directly into an optimal range, it is at least useful to know where the existing test frequency lies relative to the optimal value. From this, one can determine whether a component is being undertested or overtested. Test intervals have been historically established on the basis of deterministic industry standards such as the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. Section XI, Subsections IWP and IWV, of this code, respectively, set recommended test intervals for safety related pumps and valves. Since optimal test intervals have not been established on the basis of actual experience data, it has not been possible for testing program developers to judge whether increases in test intervals will have a positive or negative effect on component unavailability. The paper reviews the basic theory of optimal test intervals for periodically tested components, discusses recent work which addresses the effects of operational data uncertainties and demonstrates that, on the basis of actual operational reliability data, safety related pumps and motor operated valves are not being overtested. 11 refs, 2 tabs

  2. Frequency response for electromotility of isolated outer hair cells of the guinea pig

    NARCIS (Netherlands)

    Wit, HP; vanDijk, P; Segenhout, HM

    1996-01-01

    Frequency and impulse responses were determined for isolated guinea pig outer hair cells by electrically stimulating the cells between two wire electrodes with white noise. Cells were attached to the bottom of a small culture dish at one end while the other end was freely moving. Results have the ch

  3. Investigation of Frequency of Leftover Drugs at Home and Related Factors

    Directory of Open Access Journals (Sweden)

    Muharrem Ucar

    2009-04-01

    Full Text Available AIM: The purpose of this survey was to investigate the frequency of leftover drugs at homes and related factors regarding this problem. METHOD: This descriptive study was performed among 692 non-medical personnel servicing at two military bases in December 2006. Data were collected by using a questionnaire, which had been developed by the investigators. Frequencies and percents were used as descriptive statistics. Chi-square test was used to compare the frequencies of leftover drugs according to certain variables. RESULTS: Of the total participants 78,8% were males, 72,8% aged between 18 to 39, and 29,6% were unmarried. The findings revealed that 61,3% of the participants had leftover drugs at their homes. Participants living with together 2 to 4 family members had higher frequencies of leftover drugs at homes. When we looked at the frequencies of leftover drugs according to drug use behaviors; the frequency of leftover drug was determined higher among those who stated; the recipe was not explained sufficiently, he did not use drugs as directed, he kept drugs until due time when did not use all of the drugs, he kept drugs in a box or bag, he visited a health center in order to have a recipe (p<0,05. CONCLUSION: It was determined leftover drugs were kept at nearly two third of the participants’ homes. Regarding incompleteness of treatment, the intoxication risk for children, and drug waste, this frequency of drug leftover was high, and all responsible professions in the chain of rationale drug use particularly physicians should be awaked on this issue. The use of drugs in a recipe should be explained to patients clearly. [TAF Prev Med Bull 2009; 8(2.000: 113-118

  4. Effects of Sound Frequency on Audiovisual Integration: An Event-Related Potential Study.

    Science.gov (United States)

    Yang, Weiping; Yang, Jingjing; Gao, Yulin; Tang, Xiaoyu; Ren, Yanna; Takahashi, Satoshi; Wu, Jinglong

    2015-01-01

    A combination of signals across modalities can facilitate sensory perception. The audiovisual facilitative effect strongly depends on the features of the stimulus. Here, we investigated how sound frequency, which is one of basic features of an auditory signal, modulates audiovisual integration. In this study, the task of the participant was to respond to a visual target stimulus by pressing a key while ignoring auditory stimuli, comprising of tones of different frequencies (0.5, 1, 2.5 and 5 kHz). A significant facilitation of reaction times was obtained following audiovisual stimulation, irrespective of whether the task-irrelevant sounds were low or high frequency. Using event-related potential (ERP), audiovisual integration was found over the occipital area for 0.5 kHz auditory stimuli from 190-210 ms, for 1 kHz stimuli from 170-200 ms, for 2.5 kHz stimuli from 140-200 ms, 5 kHz stimuli from 100-200 ms. These findings suggest that a higher frequency sound signal paired with visual stimuli might be early processed or integrated despite the auditory stimuli being task-irrelevant information. Furthermore, audiovisual integration in late latency (300-340 ms) ERPs with fronto-central topography was found for auditory stimuli of lower frequencies (0.5, 1 and 2.5 kHz). Our results confirmed that audiovisual integration is affected by the frequency of an auditory stimulus. Taken together, the neurophysiological results provide unique insight into how the brain processes a multisensory visual signal and auditory stimuli of different frequencies.

  5. Effects of low-frequency repetitive transcranial magnetic stimulation on event-related potential P300

    Science.gov (United States)

    Torii, Tetsuya; Sato, Aya; Iwahashi, Masakuni; Iramina, Keiji

    2012-04-01

    The present study analyzed the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity. P300 latency of event-related potential (ERP) was used to evaluate the effects of low-frequency and short-term rTMS by stimulating the supramarginal gyrus (SMG), which is considered to be the related area of P300 origin. In addition, the prolonged stimulation effects on P300 latency were analyzed after applying rTMS. A figure-eight coil was used to stimulate left-right SMG, and intensity of magnetic stimulation was 80% of motor threshold. A total of 100 magnetic pulses were applied for rTMS. The effects of stimulus frequency at 0.5 or 1 Hz were determined. Following rTMS, an odd-ball task was performed and P300 latency of ERP was measured. The odd-ball task was performed at 5, 10, and 15 min post-rTMS. ERP was measured prior to magnetic stimulation as a control. Electroencephalograph (EEG) was measured at Fz, Cz, and Pz that were indicated by the international 10-20 electrode system. Results demonstrated that different effects on P300 latency occurred between 0.5-1 Hz rTMS. With 1 Hz low-frequency magnetic stimulation to the left SMG, P300 latency decreased. Compared to the control, the latency time difference was approximately 15 ms at Cz. This decrease continued for approximately 10 min post-rTMS. In contrast, 0.5 Hz rTMS resulted in delayed P300 latency. Compared to the control, the latency time difference was approximately 20 ms at Fz, and this delayed effect continued for approximately 15 min post-rTMS. Results demonstrated that P300 latency varied according to rTMS frequency. Furthermore, the duration of the effect was not similar for stimulus frequency of low-frequency rTMS.

  6. High-Pass Filtering at Vestibular Frequencies by Transducer Adaptation in Mammalian Saccular Hair Cells

    Science.gov (United States)

    Songer, Jocelyn E.; Eatock, Ruth Anne

    2011-11-01

    The mammalian saccule detects head tilt and low-frequency head accelerations as well as higher-frequency bone vibrations and sounds. It has two different hair cell types, I and II, dispersed throughout two morphologically distinct regions, the striola and extrastriola. Afferents from the two zones have distinct response dynamics which may arise partly from zonal differences in hair cell properties. We find that type II hair cells in the rat saccular epithelium adapt with a time course appropriate for influencing afferent responses to head motions. Moreover, striolar type II hair cells adapted by a greater extent than extrastriolar type II hair cells and had greater phase leads in the mid-frequency range (5-50 Hz). These differences suggest that hair cell transduction may contribute to zonal differences in the adaptation of vestibular afferents to head motions.

  7. Relative variances of the cadence frequency of cycling under two differential saddle heights.

    Science.gov (United States)

    Chang, Wen-Dien; Fan Chiang, Chin-Yun; Lai, Ping-Tung; Lee, Chia-Lun; Fang, Sz-Ming

    2016-01-01

    [Purpose] Bicycle saddle height is a critical factor for cycling performance and injury prevention. The present study compared the variance in cadence frequency after exercise fatigue between saddle heights with 25° and 35° knee flexion. [Methods] Two saddle heights, which were determined by setting the pedal at the bottom dead point with 35° and 25° knee flexion, were used for testing. The relative variances of the cadence frequency were calculated at the end of a 5-minute warm-up period and 5 minutes after inducing exercise fatigue. Comparison of the absolute values of the cadence frequency under the two saddle heights revealed a difference in pedaling efficiency. [Results] Five minutes after inducing exercise fatigue, the relative variances of the cadence frequency for the saddle height with 35° knee flexion was higher than that for the saddle height with 25° knee flexion. [Conclusion] The current finding demonstrated that a saddle height with 25° knee flexion is more appropriate for cyclists than a saddle height with 35° knee flexion. PMID:27065522

  8. VISUALIZATION OF LIP AND BASAL-CELL SKIN CANCER IN HIGH-FREQUENCY ELECTRICAL FIELD

    OpenAIRE

    Zabunyan G. A.; Ovsiyenko P. G.

    2015-01-01

    In patients, there has been registered luminescence of skin sites affected by basal cell skin cancer at stage III in high-frequency electric field. The diagnosis was confirmed by histological analysis of excised cancer sites

  9. An Imbalance between Frequency of CD4+CD25+FOXP3+ Regulatory T Cells and CCR4+ and CCR9+ Circulating Helper T Cells Is Associated with Active Perennial Allergic Conjunctivitis

    Directory of Open Access Journals (Sweden)

    J. Galicia-Carreón

    2013-01-01

    Full Text Available Allergic conjunctivitis (AC is one of the most common eye disorders in ophthalmology. In mice models, it has been suggested that control of allergic conjunctivitis is a delicate balance between Tregs and inflammatory migrating effector cells. Our aim was to evaluate the frequency of Tregs and the frequency of homing receptors expressing cells in peripheral blood mononuclear cells (PBMC from patients with perennial allergic conjunctivitis (PAC. The analyses of phenotypic markers on CD4+ T cells and both soluble or intracellular cytokines were performed by flow cytometry. CD4+CD25+ cells were 15 times more frequent in PBMC from patients than HC; the vast majority of these CD4+CD25+ cells were FOXP3−, and most of CD4+ T cells were CCR4+ and CCR9+ cells. Upon allergen-stimulation, no significant changes were observed in frequency of Treg; however, an increased frequency of CD4+CCR4+CCR9+ cells, CD4+CD103+ cells and CD4+CD108+ cells with increased IL-5, IL-6, and IL-8 production was observed. These findings suggest an immune dysregulation in PAC, characterized by diminished frequency of Tregs and increased frequency of circulating activated CD4+ T cells; upon allergen-stimulation, these cells were expressing cell-surface molecules related to mucosa homing and were able to trigger an inflammatory microenvironment.

  10. Trends in the Frequency of High Relative Humidity over China: 1979 to 2012

    Science.gov (United States)

    Mao, R.

    2015-12-01

    High relative humidity (HRH) is defined as a relative humidity of at least 80%, which is often associated with the occurrence of cloud layers. Thus, the frequency of HRH and its changes in the troposphere may be related to the occurrence frequency of cloud layers and their changes. In this study, trends in the frequency of HRH (defined as days with relative humidity ≥80%) over China from the surface to the mid-troposphere (≥400 hPa) from 1979 to 2012 were analyzed using a homogenized humidity dataset for spring (March-May), summer (June-August), autumn (September-November), and winter (December-February). The results for the ground level indicate decreasing trends at most stations in southeastern China in spring and in northern China in summer. In the lower troposphere (850 hPa and 700 hPa), most stations over China exhibited positive trends in summer, autumn, and winter. For the mid-troposphere (500 hPa to 400 hPa), increasing trends dominated over China in spring, summer, and autumn. Finally, six reanalysis datasets, including the NCEP/NCAR I, NCEP/DOE II, CFSR, ERA-Interim, MERRA, and JRA-55 datasets, were compared with the observed increasing trends in HRH frequency in the low-mid troposphere. Similar vertical profiles of HRH trends in the reanalysis datasets and the homogenized humidity dataset were observed in certain seasons and for certain regions, with positive or small negative trends at high levels and large negative trends at 850 hPa, respectively. These results are consistent with the increasing low-mid cloud amounts in recent decades.

  11. Automated Risk Identification of Myocardial Infarction Using Relative Frequency Band Coefficient (RFBC) Features from ECG

    OpenAIRE

    Bakul, Gohel; Tiwary, U.S

    2010-01-01

    Various structural and functional changes associated with ischemic (myocardial infarcted) heart cause amplitude and spectral changes in signals obtained at different leads of ECG. In order to capture these changes, Relative Frequency Band Coefficient (RFBC) features from 12-lead ECG have been proposed and used for automated identification of myocardial infarction risk. RFBC features reduces the effect of subject variabilty in body composition on the amplitude dependent features. The proposed ...

  12. Measuring stem cell frequency in epidermis: A quantitative in vivo functional assay for long-term repopulating cells

    Science.gov (United States)

    Schneider, T. E.; Barland, C.; Alex, A. M.; Mancianti, M. L.; Lu, Y.; Cleaver, J. E.; Lawrence, H. J.; Ghadially, R.

    2003-09-01

    Epidermal stem cells play a central role in tissue homeostasis, wound repair, tumor initiation, and gene therapy. A major impediment to the purification and molecular characterization of epidermal stem cells is the lack of a quantitative assay for cells capable of long-term repopulation in vivo, such as exists for hematopoietic cells. The tremendous strides made in the characterization and purification of hematopoietic stem cells have been critically dependent on the availability of competitive transplantation assays, because these assays permit the accurate quantitation of long-term repopulating cells in vivo. We have developed an analogous functional assay for epidermal stem cells, and have measured the frequency of functional epidermal stem cells in interfollicular epidermis. These studies indicate that cells capable of long-term reconstitution of a squamous epithelium reside in the interfollicular epidermis. We find that the frequency of these long-term repopulating cells is 1 in 35,000 total epidermal cells, or in the order of 1 in 104 basal epidermal cells, similar to that of hematopoietic stem cells in the bone marrow, and much lower than previously estimated in epidermis. Furthermore, these studies establish a novel functional assay that can be used to validate immunophenotypic markers and enrichment strategies for epidermal stem cells, and to quantify epidermal stem cells in various keratinocyte populations. Thus further studies using this type of assay for epidermis should aid in the progress of cutaneous stem cell-targeted gene therapy, and in more basic studies of epidermal stem cell regulation and differentiation.

  13. Frequency distribution of sickle cell anemia, sickle cell trait and sickle/beta-thalassemia among anemic patients in Saudi Arabia

    OpenAIRE

    Elsayid, Mohieldin; Al-Shehri, Mohammed Jahman; Alkulaibi, Yasser Abdullah; Alanazi, Abdullah; Qureshi, Shoeb

    2015-01-01

    Background: Notwithstanding, the growing incidence of sickle cell hemoglobinopathies (SCH) such as sickle cell anemia (SCA) or sickle cell disease, sickle/beta-thalassemia; the exact prevalence remains obscure in Saudi Arabia. Hence, this study is an attempt to determine the frequency of SCA and sickle cell trait (SCT) among all anemic patients with SCH treated at the King Abdul-Aziz Medical City (KAMC), Riyadh, Saudi Arabia. Furthermore, the hemoglobin (Hb) S and other Hb patterns (Hb AS and...

  14. The precursor frequency of alloreactive CTLs is proportional to the number of T cell epitope specificities

    Institute of Scientific and Technical Information of China (English)

    CAI E ZHANG; FEI LI GONG; SHI JIANG FEI; XIONG WEN WU; ZHI HUI LIANG; XIU FANG WENG; SHENG JUN LU; XIAO LING LU; FANG ZHEN XIA; MAO HUA ZHONG

    2006-01-01

    The aim of this study is to find the experimental evidence that the precursor frequency of alloreactive CTLs is proportional to the number of the T-cell epitope specificities. The number of T-cell epitope specificities was manipulated by pulsing different number of HLA-A2 restricted peptide(s) onto the T2 cells, which acted as stimulating cells to elicit allo-reaction by co-culturing with peripheral blood lymphocytes (PBLs) of HLA-A2 negative individual. Ten HLA-A2 restricted peptides (all were normal cell components) were synthesized, and cell peptide extract was prepared by frozen and thawed. T2 cells loaded with different number of peptide(s) were co-cultured with PBLs of an HLA-A2 negative individual; the latter were stained with PKH67 in advance. Then the proliferation was monitored with flow cytometry, and the precursor frequency of the effector cells was analyzed by the ModFit Software. After 6 d of culture, no proliferation was observed in the bulk culture of PBL alone, and obvious proliferation took place when PBLs of the HLA-A2 negative were co-cultured with T2 cells loaded with or without loading peptide(s). The precursor frequency of the alloreactive CTLs was 0.052 819 for co-culture with T2 cells loaded without peptide; however it was 0.030 429 for T2 cells with EBV/LMP2A and 0.030 528 for T2 cells loaded with a single autogeneic peptide, and increased up to 0.144 942 for T2 cells loaded with 10 autogeneic peptides; the precursor frequency was 0.203 649 when co-cultured with T2 cells loaded with miscellaneous peptides extracted from the cytoplasm of T2 cells. This study reveals that the precursor frequency of alloreactive CTLs is proportional to the number of T-cell epitope specificities, and independent of the density of the allogeneic HLA Class Ⅰ molecule.Our findings support the hypothesis that the alloreactive T cell populations comprise miscellaneous T cell clones; each is specific to corresponding pMHC. The novel constellation of peptides

  15. Remarks on nonlinear relation among phases and frequencies in modulational instabilities of parallel propagating Alfven waves

    CERN Document Server

    Nariyuki, Y; Nariyuki, Yasuhiro; Hada, Tohru

    2006-01-01

    Nonlinear relations among frequencies and phases in modulational instability of circularly polarized Alfven waves are discussed, within the context of one dimensional, dissipation-less, unforced fluid system. We show that generation of phase coherence is a natural consequence of the modulational instability of Alfven waves. Furthermore, we quantitatively evaluate intensity of wave-wave interaction by using bi-coherence, and also by computing energy flow among wave modes, and demonstrate that the energy flow is directly related to the phase coherence generation.

  16. Motivational pathways from reward sensitivity and punishment sensitivity to gambling frequency and gambling-related problems.

    Science.gov (United States)

    Wardell, Jeffrey D; Quilty, Lena C; Hendershot, Christian S; Bagby, R Michael

    2015-12-01

    Motives for gambling have been shown to have an important role in gambling behavior, consistent with the literature on motives for substance use. While studies have demonstrated that traits related to sensitivity to reward (SR) and sensitivity to punishment (SP) are predictive of substance use motives, little research has examined the role of these traits in gambling motives. This study investigated motivational pathways from SR and SP to gambling frequency and gambling problems via specific gambling motives, while also taking into account history of substance use disorder (SUD). A community sample of gamblers (N = 248) completed self-report questionnaires assessing SR, SP, gambling frequency, gambling-related problems, and motives for gambling (social, negative affect, and enhancement/winning motives). Lifetime SUD was also assessed with a structured clinical interview. The results of a path analysis showed that SR was uniquely associated with all 3 types of gambling motives, whereas SP and SUD were associated with negative affect and enhancement/winning motives but not social motives. Also, both negative affect and enhancement/winning motives were associated with gambling problems, but only enhancement/winning motives were significantly related to gambling frequency. Analyses of indirect associations revealed significant indirect associations from SR, SP, and SUD to gambling frequency mediated through enhancement/winning motives and to gambling problems mediated through both negative affect and enhancement/winning motives. The findings highlight the importance of SR and SP as independent predictors of gambling motives and suggest that specific motivational pathways underlie their associations with gambling outcomes. PMID:25915690

  17. Motivational pathways from reward sensitivity and punishment sensitivity to gambling frequency and gambling-related problems.

    Science.gov (United States)

    Wardell, Jeffrey D; Quilty, Lena C; Hendershot, Christian S; Bagby, R Michael

    2015-12-01

    Motives for gambling have been shown to have an important role in gambling behavior, consistent with the literature on motives for substance use. While studies have demonstrated that traits related to sensitivity to reward (SR) and sensitivity to punishment (SP) are predictive of substance use motives, little research has examined the role of these traits in gambling motives. This study investigated motivational pathways from SR and SP to gambling frequency and gambling problems via specific gambling motives, while also taking into account history of substance use disorder (SUD). A community sample of gamblers (N = 248) completed self-report questionnaires assessing SR, SP, gambling frequency, gambling-related problems, and motives for gambling (social, negative affect, and enhancement/winning motives). Lifetime SUD was also assessed with a structured clinical interview. The results of a path analysis showed that SR was uniquely associated with all 3 types of gambling motives, whereas SP and SUD were associated with negative affect and enhancement/winning motives but not social motives. Also, both negative affect and enhancement/winning motives were associated with gambling problems, but only enhancement/winning motives were significantly related to gambling frequency. Analyses of indirect associations revealed significant indirect associations from SR, SP, and SUD to gambling frequency mediated through enhancement/winning motives and to gambling problems mediated through both negative affect and enhancement/winning motives. The findings highlight the importance of SR and SP as independent predictors of gambling motives and suggest that specific motivational pathways underlie their associations with gambling outcomes.

  18. Data in support of dyslipidemia-associated alterations in B cell subpopulations frequency and phenotype during experimental atherosclerosis

    Directory of Open Access Journals (Sweden)

    Héctor Rincón-Arévalo

    2016-06-01

    Full Text Available Cardiovascular diseases are the most common cause of death in the world, atherosclerosis being its main underlying disease. Information about the role of B cells during atherosclerotic process is scarce, but both proatherogenic and atheroprotective properties have been described in the immunopathology of this disease. Frequency and phenotype of B cell subpopulations were studied in wild type and apolipoprotein-E-deficient (apoE−/− mice fed or not with high-fat diet (HFD, by flow cytometry. Here, we provide the information about the materials, methods, analysis and additional information related to our study published in Atherosclerosis (DOI: 10.1016/j.atherosclerosis.2015.12.022, article reference: ATH14410 [1]. The data contained in this article shows and supports that mice with advanced atherosclerosis have a variety of alterations in frequency and phenotype of B cell subsets, most of which associated with dyslipidemia.

  19. Data in support of dyslipidemia-associated alterations in B cell subpopulations frequency and phenotype during experimental atherosclerosis

    Science.gov (United States)

    Rincón-Arévalo, Héctor; Castaño, Diana; Villa-Pulgarín, Janny; Rojas, Mauricio; Vásquez, Gloria; Correa, Luis A.; Ramírez-Pineda, José R.; Yassin, Lina M.

    2016-01-01

    Cardiovascular diseases are the most common cause of death in the world, atherosclerosis being its main underlying disease. Information about the role of B cells during atherosclerotic process is scarce, but both proatherogenic and atheroprotective properties have been described in the immunopathology of this disease. Frequency and phenotype of B cell subpopulations were studied in wild type and apolipoprotein-E-deficient (apoE−/−) mice fed or not with high-fat diet (HFD), by flow cytometry. Here, we provide the information about the materials, methods, analysis and additional information related to our study published in Atherosclerosis (DOI: 10.1016/j.atherosclerosis.2015.12.022, article reference: ATH14410) [1]. The data contained in this article shows and supports that mice with advanced atherosclerosis have a variety of alterations in frequency and phenotype of B cell subsets, most of which associated with dyslipidemia. PMID:27081674

  20. Relative velocity measurement from the spectral phase of a match-filtered linear frequency modulated pulse.

    Science.gov (United States)

    Pinson, Samuel; Holland, Charles W

    2016-08-01

    Linear frequency modulated signals are commonly used to perform underwater acoustic measurements since they can achieve high signal-to-noise ratios with relatively low source levels. However, such signals present a drawback if the source or receiver or target is moving. The Doppler effect affects signal amplitude, delay, and resolution. To perform a correct match filtering that includes the Doppler shift requires prior knowledge of the relative velocity. In this paper, the relative velocity is extracted directly from the Doppler cross-power spectrum. More precisely, the quadratic coefficient of the Doppler cross-power-spectrum phase is proportional to the relative velocity. The proposed method achieves velocity estimates that compare favorably with Global Positioning System ground truth and the ambiguity method. PMID:27586779

  1. Single-Frequency GPS Relative Navigation in a High Ionosphere Orbital Environment

    Science.gov (United States)

    Conrad, Patrick R.; Naasz, Bo J.

    2007-01-01

    The Global Positioning System (GPS) provides a convenient source for space vehicle relative navigation measurements, especially for low Earth orbit formation flying and autonomous rendezvous mission concepts. For single-frequency GPS receivers, ionospheric path delay can be a significant error source if not properly mitigated. In particular, ionospheric effects are known to cause significant radial position error bias and add dramatically to relative state estimation error if the onboard navigation software does not force the use of measurements from common or shared GPS space vehicles. Results from GPS navigation simulations are presented for a pair of space vehicles flying in formation and using GPS pseudorange measurements to perform absolute and relative orbit determination. With careful measurement selection techniques relative state estimation accuracy to less than 20 cm with standard GPS pseudorange processing and less than 10 cm with single-differenced pseudorange processing is shown.

  2. Frequency and Efficacy of Talk-Related Tasks in Primary Science

    Science.gov (United States)

    Braund, Martin; Leigh, Joanne

    2013-04-01

    Pupil talk and discussion are seen as having important social and cognitive outcomes. In science classes, pupils' collaborative talk supports the construction of meaning and helps examine the status of evidence, theory and knowledge. However, pupil interactive talk in groups is rare in science lessons. The research reported is part of a project to increase the amount of pupil-pupil talk in primary schools through a programme of teaching and professional development. Pupils' self-reports of the frequency and learning efficacies of talk related activities in science lessons were collected before and after a programme of teaching in 24 schools in one of the most socially and educationally deprived areas of England. Findings showed pupils valued talking about their ideas over listening to those of other pupils. Science talk frequency (STF) was closely correlated with science talk efficacy (STE) and both were positively correlated with pupils' attitudes to school science. Analysis of covariance (ANCOVA) of the correlation of STF with STE showed values were independent of gender and ability but that school experience was a significant factor. After the teaching programme and, contrary to expectations, the frequency of talk activities in science lessons appeared to have decreased but varied according to class grades. The degree of correlation between STF and STE was stronger after the teaching in over half of the schools. Schools where STF/STE strengthened most as a result of teaching were those involved in an additional initiative to use modelled talk related to industrial contexts.

  3. Accurate encoding and decoding by single cells: amplitude versus frequency modulation.

    Directory of Open Access Journals (Sweden)

    Gabriele Micali

    2015-06-01

    Full Text Available Cells sense external concentrations and, via biochemical signaling, respond by regulating the expression of target proteins. Both in signaling networks and gene regulation there are two main mechanisms by which the concentration can be encoded internally: amplitude modulation (AM, where the absolute concentration of an internal signaling molecule encodes the stimulus, and frequency modulation (FM, where the period between successive bursts represents the stimulus. Although both mechanisms have been observed in biological systems, the question of when it is beneficial for cells to use either AM or FM is largely unanswered. Here, we first consider a simple model for a single receptor (or ion channel, which can either signal continuously whenever a ligand is bound, or produce a burst in signaling molecule upon receptor binding. We find that bursty signaling is more accurate than continuous signaling only for sufficiently fast dynamics. This suggests that modulation based on bursts may be more common in signaling networks than in gene regulation. We then extend our model to multiple receptors, where continuous and bursty signaling are equivalent to AM and FM respectively, finding that AM is always more accurate. This implies that the reason some cells use FM is related to factors other than accuracy, such as the ability to coordinate expression of multiple genes or to implement threshold crossing mechanisms.

  4. Calcium signalling in human neutrophil cell lines is not affected by low-frequency electromagnetic fields.

    Science.gov (United States)

    Golbach, Lieke A; Philippi, John G M; Cuppen, Jan J M; Savelkoul, Huub F J; Verburg-van Kemenade, B M Lidy

    2015-09-01

    We are increasingly exposed to low-frequency electromagnetic fields (LF EMFs) by electrical devices and power lines, but if and how these fields interact with living cells remains a matter of debate. This study aimed to investigate the potential effect of LF EMF exposure on calcium signalling in neutrophils. In neutrophilic granulocytes, activation of G-protein coupled receptors leads to efflux of calcium from calcium stores and influx of extracellular calcium via specialised calcium channels. The cytoplasmic rise of calcium induces cytoskeleton rearrangements, modified gene expression patterns, and cell migration. If LF EMF modulates intracellular calcium signalling, this will influence cellular behaviour and may eventually lead to health problems. We found that calcium mobilisation upon chemotactic stimulation was not altered after a short 30 min or long-term LF EMF exposure in human neutrophil-like cell lines HL-60 or PLB-985. Neither of the two investigated wave forms (Immunent and 50 Hz sine wave) at three magnetic flux densities (5 μT, 300 μT, and 500 μT) altered calcium signalling in vitro. Gene-expression patterns of calcium-signalling related genes also did not show any significant changes after exposure. Furthermore, analysis of the phenotypical appearance of microvilli by scanning electron microscopy revealed no alterations induced by LF EMF exposure. The findings above indicate that exposure to 50 Hz sinusoidal or Immunent LF EMF will not affect calcium signalling in neutrophils in vitro.

  5. B-cell infiltration and frequency of cytokine producing cells differ between localized and disseminated human cutaneous leishmaniases

    Directory of Open Access Journals (Sweden)

    MGS Vieira

    2002-10-01

    Full Text Available Biopsies from human localized cutaneous lesions (LCL n = 7 or disseminated lesions (DL n = 8 cases were characterized according to cellular infiltration,frequency of cytokine (IFN-g, TNF-alpha or iNOS enzyme producing cells. LCL, the most usual form of the disease with usually one or two lesions, exhibits extensive tissue damage. DL is a rare form with widespread lesions throughout the body; exhibiting poor parasite containment but less tissue damage. We demonstrated that LCL lesions exhibit higher frequency of B lymphocytes and a higher intensity of IFN-gamma expression. In both forms of the disease CD8+ were found in higher frequency than CD4+ T cells. Frequency of TNF-alpha and iNOS producing cells, as well as the frequency of CD68+ macrophages, did not differ between LCL and DL. Our findings reinforce the link between an efficient control of parasite and tissue damage, implicating higher frequency of IFN-gamma producing cells, as well as its possible counteraction by infiltrated B cells and hence possible humoral immune response in situ.

  6. Testing General Relativity with Low-Frequency, Space-Based Gravitational-Wave Detectors

    Directory of Open Access Journals (Sweden)

    John G. Baker

    2013-09-01

    Full Text Available We review the tests of general relativity that will become possible with space-based gravitational-wave detectors operating in the ∼ 10^{-5} – 1 Hz low-frequency band. The fundamental aspects of gravitation that can be tested include the presence of additional gravitational fields other than the metric; the number and tensorial nature of gravitational-wave polarization states; the velocity of propagation of gravitational waves; the binding energy and gravitational-wave radiation of binaries, and therefore the time evolution of binary inspirals; the strength and shape of the waves emitted from binary mergers and ringdowns; the true nature of astrophysical black holes; and much more. The strength of this science alone calls for the swift implementation of a space-based detector; the remarkable richness of astrophysics, astronomy, and cosmology in the low-frequency gravitational-wave band make the case even stronger.

  7. Alcohol drinking frequency in relation to subsequent changes in waist circumference

    DEFF Research Database (Denmark)

    Tolstrup, J.S.; Halkjaer, J.; Heitmann, B.L.;

    2008-01-01

    a prospective cohort study conducted in 1993-1997 (baseline) and 1999-2002 (follow-up) and included 43 543 men and women. Baseline information on alcohol drinking frequency was related to 1) change in waist circumference by linear regression and 2) major gain and major loss in waist circumference (defined...... as waist change in the lowest or highest quintile of waist changes) by polytomous logistic regression, also taking into account amount of alcohol intake. RESULTS: Drinking frequency was inversely associated with changes in waist circumference in women and was unassociated with changes in waist...... drinking, drinking on 1, 2-4, 5-6, and 7 d/wk, respectively, compared with men who drank alcohol on alcohol intake or total energy intake did not affect results considerably. CONCLUSIONS: Drinking pattern may...

  8. Absolute and relative surface profile interferometry using multiple frequency-scanned lasers

    CERN Document Server

    Peca, Marek; Vojtíšek, Petr; Lédl, Vít

    2016-01-01

    An interferometer has been used to measure the surface profile of generic object. Frequency scanning interferometry has been employed to provide unambiguous phase readings, to suppress etalon fringes, and to supersede phase-shifting. The frequency scan has been performed in three narrow wavelength bands, each generated by a temperature tuned laser diode. It is shown, that for certain portions of measured object, it was possible to get absolute phase measurement, counting all wave periods from the point of zero path difference, yielding precision of 2.7nm RMS over 11.75mm total path difference. For the other areas where steep slopes were present in object geometry, a relative measurement is still possible, at measured surface roughness comparable to that of machining process (the same 2.7nm RMS). It is concluded, that areas containing steep slopes exhibit systematic error, attributed to a combined factors of dispersion and retrace error.

  9. Finite-Element Modeling of Viscoelastic Cells During High-Frequency Cyclic Strain

    Directory of Open Access Journals (Sweden)

    David W. Holdsworth

    2012-03-01

    Full Text Available Mechanotransduction refers to the mechanisms by which cells sense and respond to local loads and forces. The process of mechanotransduction plays an important role both in maintaining tissue viability and in remodeling to repair damage; moreover, it may be involved in the initiation and progression of diseases such as osteoarthritis and osteoporosis. An understanding of the mechanisms by which cells respond to surrounding tissue matrices or artificial biomaterials is crucial in regenerative medicine and in influencing cellular differentiation. Recent studies have shown that some cells may be most sensitive to low-amplitude, high-frequency (i.e., 1–100 Hz mechanical stimulation. Advances in finite-element modeling have made it possible to simulate high-frequency mechanical loading of cells. We have developed a viscoelastic finite-element model of an osteoblastic cell (including cytoskeletal actin stress fibers, attached to an elastomeric membrane undergoing cyclic isotropic radial strain with a peak value of 1,000 µstrain. The results indicate that cells experience significant stress and strain amplification when undergoing high-frequency strain, with peak values of cytoplasmic strain five times higher at 45 Hz than at 1 Hz, and peak Von Mises stress in the nucleus increased by a factor of two. Focal stress and strain amplification in cells undergoing high-frequency mechanical stimulation may play an important role in mechanotransduction.

  10. High-frequency intrachromosomal gene conversion induced by triplex-forming oligonucleotides microinjected into mouse cells

    OpenAIRE

    Luo, Zhongjun; Macris, Margaret A.; Faruqi, A. Fawad; Glazer, Peter M.

    2000-01-01

    To test the ability of triple helix-forming oligonucleotides (TFOs) to promote recombination within chromosomal sites in mammalian cells, a mouse LTK− cell line was established carrying two mutant copies of the herpes simplex virus thymidine kinase (TK) gene as direct repeats in a single chromosomal locus. Recombination between these repeats can produce a functional TK gene and occurs at a spontaneous frequency of 4 × 10−6 under standard culture conditions. When cells were microinjected with ...

  11. Micronucleus frequency in exfoliated buccal cells from hairdresser who expose to hair products

    Directory of Open Access Journals (Sweden)

    Koh Hui Yee

    2015-06-01

    Full Text Available Background: Hairdresser is one of the fastest growing occupations in today’s society. Hairdresser help styling, cutting, colouring, perming, curling, straightening hair and various treatment to customer. Somehow, hairdresser are constantly exposed to chemical substances such as aromatic amines, hydrogen peroxide, thioglycolic acid, formaldehyde in hair products which can cause damage to human’s genome. Micronucleus is one of the effective biomarker for processes associated with the induction of DNA damage. Purpose: The aim of this study was to determine the micronucleus frequencies in buccal mucosa epithelial cells of hairdresser who were exposed to chemical of hair products. Method: This study was conducted on twenty female subjects, who were divided into 2 groups: exposed and non-exposed (control group. All subjects recruited were working in the same beauty salon. Buccal cells were obtained from each individual by using cytobrush. The cells were stained with modified Feulgen-Ronssenback method and counting of micronucleus per 1000 cell was done under light microscope. The data were analyzed using independent t-test and one-way Anova (p<0.05. Result: The result showed a significant difference in micronucleus frequency between 2 groups. There were a significantly increase of micronucleus frequency in hairdressers and increase of  micronucleus frequency with the longer duration of exposure. Conclusion: It concluded that the chemical substances of hair products had affected the micronucleus frequency ofthe epithelial cells in buccal mucosa of hairdressers.

  12. Nature's starships. I. Observed abundances and relative frequencies of amino acids in meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, Alyssa K.; Pudritz, Ralph E., E-mail: cobbak@mcmaster.ca, E-mail: pudritz@physics.mcmaster.ca [Origins Institute, McMaster University, ABB 241, 1280 Main Street, Hamilton, ON L8S 4M1 (Canada)

    2014-03-10

    The class of meteorites called carbonaceous chondrites are examples of material from the solar system which have been relatively unchanged from the time of their initial formation. These meteorites have been classified according to the temperatures and physical conditions of their parent planetesimals. We collate available data on amino acid abundance in these meteorites and plot the concentrations of different amino acids for each meteorite within various meteorite subclasses. We plot average concentrations for various amino acids across meteorites separated by subclass and petrologic type. We see a predominance in the abundance and variety of amino acids in CM2 and CR2 meteorites. The range in temperature corresponding to these subclasses indicates high degrees of aqueous alteration, suggesting aqueous synthesis of amino acids. Within the CM2 and CR2 subclasses, we identify trends in relative frequencies of amino acids to investigate how common amino acids are as a function of their chemical complexity. These two trends (total abundance and relative frequencies) can be used to constrain formation parameters of amino acids within planetesimals. Our organization of the data supports an onion shell model for the temperature structure of planetesimals. The least altered meteorites (type 3) and their amino acids originated near cooler surface regions. The most active amino acid synthesis likely took place at intermediate depths (type 2). The most altered materials (type 1) originated furthest toward parent body cores. This region is likely too hot to either favor amino acid synthesis or for amino acids to be retained after synthesis.

  13. Frequency of Color Vision Defect in Students of Mashhad Dental School and Evaluation of Related Factors

    Directory of Open Access Journals (Sweden)

    Mohammad Daryaeian

    Full Text Available Introduction: In esthetic dentistry, color matching ability is one of the influencing factors in treatment. To achieve this goal, matching the color of restoration with natural teeth is essential. The objective of this study was to determine the frequency of color vision defect in students of Mashhad Dental School and evaluation of related factors.Materials & Methods: In this descriptive analytical study, 356 students of Mashhad Dental School were evaluated. Demographic data including age, gender, color vision defect in relatives, use of glasses and contact lenses, refractive errors (myopia, hypermetropia and astigmatism were documented in the designed questionnaire. To determine the impaired color vision, Ishihara diagnostic test was used. Statistical analysis of SPSS version 19 was performed using Chi-Square and Logistic Regression tests at the significance level of 0.05%.Results: Color vision defect was found in 6% (12 persons of male students while none of the females were affected. All affected persons were red-green color blind and strong deutan. There was a significant relationship between color vision deficiency and history of color vision defect in relatives (P= 0.03, so that 25% (3 persons of affected persons had a positive family history of color vision defect. Conclusion: Considering the frequency of color vision defect in the present study as well as the importance of color matching in dental treatments and because most affected persons are unaware of this defect, color vision tests seem necessary.

  14. THE FREQUENCY INVESTIGATION OF THE NEWS RELATED TO VIOLENCE IN SPORTS IN PRINTED MEDIA

    OpenAIRE

    Gül; Musa; Şaban; M. Yalçın

    2015-01-01

    News related to violence in sports in the printed media has critical importance in violence perception of society. That is why, it has become an important issue to make descriptive evaluation of the news about violence in sports in the printed media. The purpose of the present study was to determine how often the news about violence in sports took place in the printed media. This study was done using scanning method that covered total time period of 227 days. During this time period, frequenc...

  15. Frequency, sensitivity and specificity of roentgenographic features of slight and moderate asbestos-related respiratory diseases

    International Nuclear Information System (INIS)

    The possibility of early detection of asbestos-related respiratory diseases was examined on the basis of four x-ray abnormalities, namely, pulmonary fibrosis, pleural plaque, diffuse pleural thickening and diaphragmatic calcification, in a group of workers exposed to chrysotile asbestos. The frequency of these phenomena was compared to the unexposed control group of similar distribution of number, sex and age. Besides the pleural plaques, which had a high specificity, the combination of minor x-ray abnormalities proved to be most characteristic of exposure to asbestos. The more frequent one of the abnormalities, the less specificity it had to asbestos exposure. (orig.)

  16. Relative validities of 3-day food records and the food frequency questionnaire

    OpenAIRE

    Yang, Yoon Jung; Kim, Mi Kyung; Hwang, Se Hee; Ahn, Younjhin; Shim, Jae Eun; Kim, Dong Hyun

    2010-01-01

    The food frequency questionnaire (FFQ) has been used as an important dietary assessment tool in epidemiologic studies, but the usefulness of the FFQ has been debated in recent years. This study was performed to evaluate the relative validities of 3-day food records and the semi-quantitative FFQ. A total of 124 subjects finished 3-day food records (FRs) during each of the four seasons, as well as the FFQ from December 2002 to May 2004. The FFQ was a food based semi-quantitative FFQ including 1...

  17. High frequency fluidic and microfluidic sensors for contactless dielectric and in vitro cell culture measurement applications

    Science.gov (United States)

    Nacke, T.; Barthel, A.; Cahill, B. P.; Meister, M.; Zaikou, Y.

    2013-04-01

    There is a widespread need for highly-sensitive robust sensors that operate without direct contact to the fluid for analysis of fluids in bioprocess technology. Measuring the variation of dielectric properties (conductivity and permittivity) in the microwave frequency band can be used as an approach to investigate biological and chemical matter and processes such as, cell growth, cell metabolism and the concentration of large aqueous based molecules. In comparison to measurement at lower frequencies, DC conductivity (σ) effects on material properties (permittivity ε) can be neglected with increasing of the frequency. This presentation describes a high frequency sensor, which combines detection in macro- or microfluidic networks with quick and precise analysis. It is composed of a fluidic channel placed contactless between a micro-strip line waveguide combined with resonant properties.

  18. Inductive phenomena at low frequencies in impedance spectra of proton exchange membrane fuel cells - A review

    Science.gov (United States)

    Pivac, Ivan; Barbir, Frano

    2016-09-01

    The results of electrochemical impedance spectroscopy of proton exchange membrane (PEM) fuel cells may exhibit inductive phenomena at low frequencies. The occurrence of inductive features at high frequencies is explained by the cables and wires of the test system. However, explanation of inductive loop at low frequencies requires a more detailed study. This review paper discusses several possible causes of such inductive behavior in PEM fuel cells, such as side reactions with intermediate species, carbon monoxide poisoning, and water transport, also as their equivalent circuit representations. It may be concluded that interpretation of impedance spectra at low frequencies is still ambiguous, and that better equivalent circuit models are needed with clearly defined physical meaning of each of the circuit elements.

  19. High frequency fluidic and microfluidic sensors for contactless dielectric and in vitro cell culture measurement applications

    International Nuclear Information System (INIS)

    There is a widespread need for highly-sensitive robust sensors that operate without direct contact to the fluid for analysis of fluids in bioprocess technology. Measuring the variation of dielectric properties (conductivity and permittivity) in the microwave frequency band can be used as an approach to investigate biological and chemical matter and processes such as, cell growth, cell metabolism and the concentration of large aqueous based molecules. In comparison to measurement at lower frequencies, DC conductivity (σ) effects on material properties (permittivity ε) can be neglected with increasing of the frequency. This presentation describes a high frequency sensor, which combines detection in macro- or microfluidic networks with quick and precise analysis. It is composed of a fluidic channel placed contactless between a micro-strip line waveguide combined with resonant properties.

  20. Frequencies of maternal red blood cell alloantibodies in Port Harcourt, Nigeria

    Directory of Open Access Journals (Sweden)

    Jeremiah Zaccheaus

    2011-01-01

    Full Text Available Background: Alloantibodies of clinical importance can cause transfusion reactions or hemolytic disease of the fetus and newborn (HDFN. The frequencies of these antibodies have not been reported in our locality. Aims: To determine the frequency of occurrence of alloantibodies among pregnant women in Port Harcourt, Nigeria. Settings and Design: This is a prospective study, which was carried out in the Braithwaite Memorial Specialist Hospital, Port Harcourt, Nigeria. Materials and Methods: Screening and identification of red blood cell alloantibodies was done on the sera of 500 pregnant women using the DiaMed, DiaCell, and DiaPanel reagents (Cressier, Switzerland. ABO and Rh blood groups were done using antisera bought from Biotec (Ipswich, UK. Results: Alloantibodies were identified in the serum of 17 of the 500 (3.4% pregnant women. The specificity of the antibodies was as follows: anti-C 6 (1.2%, anti-E 3 (0.6%, anti-Jsb 3 (0.6%, and anti-K 5 (1.0%. No anti-D was identified despite 8.6% of the study population being Rhesus D (Rh D negative. The distribution of the antibodies was found to be independent of the blood groups of the participants (x 2 = 4.050, P = 0.670. Blood group O constituted the highest percentage (48.0%. Conclusion: This study has identified the presence of non-Rh D antibodies to the proportion of 3.4%. Rh D antibody was absent in this population irrespective of the relatively high percentage of Rh D negative women. There is a need to determine the actual risk these antibodies may pose to the antenatal women and to include antibody screening and identification in routine antenatal care.

  1. Frequencies and specificities of red cell alloantibodies in the Southern Thai population

    OpenAIRE

    Charuporn Promwong; Santi Siammai; Sarunya Hassarin; Jarin Buakaew; Tanongsak Yeela; Patravee Soisangwan; David Roxby

    2013-01-01

    Context: Detailed reports of red cell alloantibody frequencies and specificities in the Thai population are limited. The aims of this study were to determine the specificity and compare the frequency of alloantibodies detected using column agglutination technology (CAT) and conventional tube techniques in blood donors and previously transfused patients. Settings and Design: We retrospectively reviewed antibody screening and identification records for two time periods: January-December 2006 du...

  2. THE FREQUENCY INVESTIGATION OF THE NEWS RELATED TO VIOLENCE IN SPORTS IN PRINTED MEDIA

    Directory of Open Access Journals (Sweden)

    Gül

    2015-08-01

    Full Text Available News related to violence in sports in the printed media has critical importance in violence perception of society. That is why, it has become an important issue to make descriptive evaluation of the news about violence in sports in the printed media. The purpose of the present study was to determine how often the news about violence in sports took place in the printed media. This study was done using scanning method that covered total time period of 227 days. During this time period, frequency, number, type (written or photos, length, source, sports branch and organizations of the news related to violence in sports in the national daily newspapers (HABERTÜRK, HÜRRİYET and the daily sports newspapers (FANATİK, FOTOMAÇ were determined and the results were evaluated. With that in mind, the news related to violence were first categorized as fallows and then examined; “Europe and Turkey”, “Soccer and other branches”, “League categories”, which club is related to most”, and “Source of Violence. For statistical analysis, the frequency and the percentage of data were calculated and chi-square test was used with the help of SPSS (version 19.0. In addition, consistency analysis was done to determine the relationship among the different level of variables. As a result of this study, it was understood that news related to violence was more focused on soccer and soccer spectators are the main actors of violence in sports. It could be speculated that, media organizations should publish the news, especially violence in soccer, in more responsible manner to cease the tension in violence perception of society.

  3. Increased frequency of single base substitutions in a population of transcripts expressed in cancer cells

    Directory of Open Access Journals (Sweden)

    Bianchetti Laurent

    2012-11-01

    Full Text Available Abstract Background Single Base Substitutions (SBS that alter transcripts expressed in cancer originate from somatic mutations. However, recent studies report SBS in transcripts that are not supported by the genomic DNA of tumor cells. Methods We used sequence based whole genome expression profiling, namely Long-SAGE (L-SAGE and Tag-seq (a combination of L-SAGE and deep sequencing, and computational methods to identify transcripts with greater SBS frequencies in cancer. Millions of tags produced by 40 healthy and 47 cancer L-SAGE experiments were compared to 1,959 Reference Tags (RT, i.e. tags matching the human genome exactly once. Similarly, tens of millions of tags produced by 7 healthy and 8 cancer Tag-seq experiments were compared to 8,572 RT. For each transcript, SBS frequencies in healthy and cancer cells were statistically tested for equality. Results In the L-SAGE and Tag-seq experiments, 372 and 4,289 transcripts respectively, showed greater SBS frequencies in cancer. Increased SBS frequencies could not be attributed to known Single Nucleotide Polymorphisms (SNP, catalogued somatic mutations or RNA-editing enzymes. Hypothesizing that Single Tags (ST, i.e. tags sequenced only once, were indicators of SBS, we observed that ST proportions were heterogeneously distributed across Embryonic Stem Cells (ESC, healthy differentiated and cancer cells. ESC had the lowest ST proportions, whereas cancer cells had the greatest. Finally, in a series of experiments carried out on a single patient at 1 healthy and 3 consecutive tumor stages, we could show that SBS frequencies increased during cancer progression. Conclusion If the mechanisms generating the base substitutions could be known, increased SBS frequency in transcripts would be a new useful biomarker of cancer. With the reduction of sequencing cost, sequence based whole genome expression profiling could be used to characterize increased SBS frequency in patient’s tumor and aid diagnostic.

  4. Multipolar universal relations between f-mode frequency and tidal deformability of compact stars

    CERN Document Server

    Chan, T K; Leung, P T; Lin, L -M

    2014-01-01

    Though individual stellar parameters of compact stars usually demonstrate obvious dependence on the equation of state (EOS), EOS-insensitive universal formulas relating these parameters remarkably exist. In the present paper, we explore the inter-relationship between two such formulas, namely the f-I relation connecting the $f$-mode quadrupole oscillation frequency $\\omega_2$ and the moment of inertia $I$, and the I-Love-Q relations relating $I$, the quadrupole tidal deformability $\\lambda_2$, and the quadrupole moment $Q$, which have been proposed by Lau et al. [Astrophys. J. {\\bf 714}, 1234 (2010)], and Yagi and Yunes [Science, {\\bf 341}, 365 (2013)], respectively. A relativistic universal relation between $\\omega_l$ and $\\lambda_l$ with the same angular momentum $l=2,3,\\ldots$, the so called "diagonal f-Love relation" that holds for realistic compact stars and stiff polytropic stars, is unveiled here. An in-depth investigation in the Newtonian limit is further carried out to pinpoint its underlying physica...

  5. Frequency sweep rate dependence on the dielectrophoretic response of polystyrene beads and red blood cells

    Science.gov (United States)

    Adams, T. N. G.; Leonard, K. M.; Minerick, A. R.

    2013-01-01

    Alternating current (AC) dielectrophoresis (DEP) experiments for biological particles in microdevices are typically done at a fixed frequency. Reconstructing the DEP response curve from static frequency experiments is laborious, but essential to ascertain differences in dielectric properties of biological particles. Our lab explored the concept of sweeping the frequency as a function of time to rapidly determine the DEP response curve from fewer experiments. For the purpose of determining an ideal sweep rate, homogeneous 6.08 μm polystyrene (PS) beads were used as a model system. Translatability of the sweep rate approach to ∼7 μm red blood cells (RBC) was then verified. An Au/Ti quadrapole electrode microfluidic device was used to separately subject particles and cells to 10Vpp AC electric fields at frequencies ranging from 0.010 to 2.0 MHz over sweep rates from 0.00080 to 0.17 MHz/s. PS beads exhibited negative DEP assembly over the frequencies explored due to Maxwell-Wagner interfacial polarizations. Results demonstrate that frequency sweep rates must be slower than particle polarization timescales to achieve reliable incremental polarizations; sweep rates near 0.00080 MHz/s yielded DEP behaviors very consistent with static frequency DEP responses for both PS beads and RBCs. PMID:24396548

  6. On natural frequencies of non-uniform beams modulated by finite periodic cells

    Science.gov (United States)

    Xu, Yanlong; Zhou, Xiaoling; Wang, Wei; Wang, Longqi; Peng, Fujun; Li, Bin

    2016-09-01

    It is well known that an infinite periodic beam can support flexural wave band gaps. However, in real applications, the number of the periodic cells is always limited. If a uniform beam is replaced by a non-uniform beam with finite periodicity, the vibration changes are vital by mysterious. This paper employs the transfer matrix method (TMM) to study the natural frequencies of the non-uniform beams with modulation by finite periodic cells. The effects of the amounts, cross section ratios, and arrangement forms of the periodic cells on the natural frequencies are explored. The relationship between the natural frequencies of the non-uniform beams with finite periodicity and the band gap boundaries of the corresponding infinite periodic beam is also investigated. Numerical results and conclusions obtained here are favorable for designing beams with good vibration control ability.

  7. Tunable chemokine production by antigen presenting dendritic cells in response to changes in regulatory T cell frequency in mouse reactive lymph nodes.

    Directory of Open Access Journals (Sweden)

    Valentina Dal Secco

    Full Text Available BACKGROUND: Although evidence exists that regulatory T cells (Tregs can suppress the effector phase of immune responses, it is clear that their major role is in suppressing T cell priming in secondary lymphoid organs. Recent experiments using two photon laser microscopy indicate that dendritic cells (DCs are central to Treg cell function and that the in vivo mechanisms of T cell regulation are more complex than those described in vitro. PRINCIPAL FINDINGS: Here we have sought to determine whether and how modulation of Treg numbers modifies the lymph node (LN microenvironment. We found that pro-inflammatory chemokines -- CCL2 (MCP-1 and CCL3 (MIP-la -- are secreted in the LN early (24 h after T cell activation, that this secretion is dependent on antigen-specific DC-T cell interactions, and that it was inversely related to the frequency of Tregs specific for the same antigen. Furthermore, we demonstrate that Tregs modify the chemoattractant properties of antigen-presenting DCs, which, as the frequency of Tregs increases, fail to produce CCL2 and CCL3 and to attract antigen-specific T cells. CONCLUSIONS: These results substantiate a major role of Tregs in LN patterning during antigen-specific immune responses.

  8. Nature's Starships. I. Observed Abundances and Relative Frequencies of Amino Acids in Meteorites

    CERN Document Server

    Cobb, Alyssa K

    2014-01-01

    The class of meteorites called carbonaceous chondrites are examples of material from the solar system which have been relatively unchanged from the time of their initial formation. These meteorites have been classified according to the temperatures and physical conditions of their parent planetesimals. We collate available data on amino acid abundance in these meteorites and plot the concentrations of different amino acids for each meteorite within various meteorite subclasses. We plot average concentrations for various amino acids across meteorites separated by subclass and petrologic type. We see a predominance in the abundance and variety of amino acids in CM2 and CR2 meteorites. The range in temperature corresponding to these subclasses indicates high degrees of aqueous alteration, suggesting aqueous synthesis of amino acids. Within the CM2 and CR2 subclasses, we identify trends in relative frequencies of amino acids to investigate how common amino acids are as a function of their chemical complexity. The...

  9. Data on correlations between T cell subset frequencies and length of partial remission in type 1 diabetes.

    Science.gov (United States)

    Narsale, Aditi; Moya, Rosita; Robertson, Hannah Kathryn; Davies, Joanna Davida

    2016-09-01

    Partial remission in patients newly diagnosed with type 1 diabetes is a period of good glucose control that can last from several weeks to over a year. The clinical significance of the remission period is that patients might be more responsive to immunotherapy if treated within this period. This article provides clinical data that indicates the level of glucose control and insulin-secreting β-cell function of each patient in the study at baseline (within 3 months of diagnosis), and at 3, 6, 9, 12, 18 and 24 months post-baseline. The relative frequency of immune cell subsets in the PBMC of each patient and the association between the frequency of immune cell subsets measured and length of remission is also shown. These data support the findings reported in the accompanying publication, "A pilot study showing associations between frequency of CD4+ memory cell subsets at diagnosis and duration of partial remission in type 1 diabetes" (Moya et al., 2016) [1], where a full interpretation, including biological relevance of the study can be found. PMID:27579340

  10. Methods, compositions and kits for imaging cells and tissues using nanoparticles and spatial frequency heterodyne imaging

    Energy Technology Data Exchange (ETDEWEB)

    Rose-Petruck, Christoph; Wands, Jack R.; Rand, Danielle; Derdak, Zoltan; Ortiz, Vivian

    2016-04-19

    Methods, compositions, systems, devices and kits are provided herein for preparing and using a nanoparticle composition and spatial frequency heterodyne imaging for visualizing cells or tissues. In various embodiments, the nanoparticle composition includes at least one of: a nanoparticle, a polymer layer, and a binding agent, such that the polymer layer coats the nanoparticle and is for example a polyethylene glycol, a polyelectrolyte, an anionic polymer, or a cationic polymer, and such that the binding agent that specifically binds the cells or the tissue. Methods, compositions, systems, devices and kits are provided for identifying potential therapeutic agents in a model using the nanoparticle composition and spatial frequency heterodyne imaging.

  11. Frequency and Risk Factors of Endocrine Complications in Turkish Children and Adolescents with Sickle Cell Anemia

    Directory of Open Access Journals (Sweden)

    Samim Özen

    2013-03-01

    Full Text Available Objective: To define frequency and risk factors of abnormalities in growth, puberty, thyroid function, and bone and carbohydrate metabolisms in children and adolescents with sickle cell disease (SCD. Materials and Methods: Endocrine problems including short stature, puberty and thyroid disorders, and carbohydrate and bone metabolisms in 50 Turkish children and adolescents with SCD were evaluated. Relationships among sex, disease type, blood transfusions, exchange and exacerbation frequency, ferritin levels, and endocrine pathologies were investigated. Results: The mean age of the study group was 13.1±2.9 years. Weights and heights of 12 participants (24% were below -2 standard deviations and 4 participants (8% had malnutrition. Mean difference (±standard deviation between bone and chronological age of patients was -1.73±1.86 years. Fifty percent of patients had at least one endocrine abnormality other than vitamin D deficiency and insufficiency. Hypergonadotropic hypogonadism in 3 patients (6%, hypogonadotropic hypogonadism in 1 female patient (2%, and small testicular volume in respect to age in 3 male patients (8.5% were seen. Growth hormone deficiency was detected in 1 (2% female patient, and hypothyroidism was diagnosed in 3 patients (6%; 1 central case, 2 cases of primary hypothyroidism. At vertebral level, 5 patients (11.1% had osteopenia and 1 patient (2.2% had osteoporosis, while 5 patients (11.1% had osteopenia at femur neck level. The most common endocrine abnormality was vitamin D deficiency. 25-Hydroxyvitamin D was deficient in 63.2% and insufficient in 18.4% of patients. Sex, disease type, blood transfusion frequency, exacerbation frequency, and ferritin levels were not related to endocrine pathologies. As the age was increased, standard deviation scores of femur neck bone mineral density was decreased (r =-0.56; p<0.05. Vitamin D was lower in patients whose weights and/or heights were below -2 standard deviations from the mean

  12. Mechanical properties of single cells by high-frequency time-resolved acoustic microscopy.

    Science.gov (United States)

    Weiss, Eike C; Anastasiadis, Pavlos; Pilarczyk, Götz; Lemor, Robert M; Zinin, Pavel V

    2007-11-01

    In this paper, we describe a new, high-frequency, time-resolved scanning acoustic microscope developed for studying dynamical processes in biological cells. The new acoustic microscope operates in a time-resolved mode. The center frequency is 0.86 GHz, and the pulse duration is 5 ns. With such a short pulse, layers thicker than 3 microm can be resolved. For a cell thicker than 3 microm, the front echo and the echo from the substrate can be distinguished in the signal. Positions of the first and second pulses are used to determine the local impedance of the cell modeled as a thin liquid layer that has spatial variations in its elastic properties. The low signal-to-noise ratio in the acoustical images is increased for image generation by averaging the detected radio frequency signal over 10 measurements at each scanning point. In conducting quantitative measurements of the acoustic parameters of cells, the signal can be averaged over 2000 measurements. This approach enables us to measure acoustical properties of a single HeLa cell in vivo and to derive elastic parameters of subcellular structures. The value of the sound velocity inside the cell (1534.5 +/- 33.6 m/s) appears to be only slightly higher than that of the cell medium (1501 m/s). PMID:18051160

  13. Frequency-dependent, cell type-divergent signaling in the hippocamposeptal projection.

    Science.gov (United States)

    Mattis, Joanna; Brill, Julia; Evans, Suzanne; Lerner, Talia N; Davidson, Thomas J; Hyun, Minsuk; Ramakrishnan, Charu; Deisseroth, Karl; Huguenard, John R

    2014-08-27

    Hippocampal oscillations are critical for information processing, and are strongly influenced by inputs from the medial septum. Hippocamposeptal neurons provide direct inhibitory feedback from the hippocampus onto septal cells, and are therefore likely to also play an important role in the circuit; these neurons fire at either low or high frequency, reflecting hippocampal network activity during theta oscillations or ripple events, respectively. Here, we optogenetically target the long-range GABAergic projection from the hippocampus to the medial septum in rats, and thereby simulate hippocampal input onto downstream septal cells in an acute slice preparation. In response to optogenetic activation of hippocamposeptal fibers at theta and ripple frequencies, we elicit postsynaptic GABAergic responses in a subset (24%) of septal cells, most predominantly in fast-spiking cells. In addition, in another subset of septal cells (19%) corresponding primarily to cholinergic cells, we observe a slow hyperpolarization of the resting membrane potential and a decrease in input resistance, particularly in response to prolonged high-frequency (ripple range) stimulation. This slow response is partially sensitive to GIRK channel and D2 dopamine receptor block. Our results suggest that two independent populations of septal cells distinctly encode hippocampal feedback, enabling the septum to monitor ongoing patterns of activity in the hippocampus.

  14. Frequency of referral of patients with safety-related contraindications to magnetic resonance imaging

    International Nuclear Information System (INIS)

    Purpose: To analyse the frequency of patients with absolute and relative contraindications to magnetic resonance (MR) imaging who were actually referred to an outpatient imaging centre for an MR examination Materials and methods: Altogether a total of 51,547 consecutive patients were included between November 1997 and December 2005. Reasons preventing MR imaging were classified into the following categories: absolute and relative contraindications. Results: The referral frequency of patients with absolute contraindications to MR imaging was 0.41% (211 of 51,547 patients; 95% CI, 0.36-0.47%). The absolute contraindications were shrapnels located in biologically sensitive areas (121 patients, 0.23%; 95% CI, 0.20-0.28%), cardiac pacemakers (42 patients, 0.08%; 95% CI, 0.06-0.11%), and other unsafe implants (48 patients, 0.09%; 95% CI, 0.07-0.12%). Also patients with a relative contraindication to MR imaging were referred such as women with a first-trimester pregnancy (13 patients, 0.03%; 95% CI, 0.01-0.04%). Conclusion: Surprisingly, a considerable number of patients (0.41%) with cardiac pacemakers, other metallic implants (not approved for MR), or shrapnels are referred to MR facilities despite the well-known recommendations not to examine such patients. Thus, absolute contraindications to MR imaging are commonly found among patients referred for MR examinations and every effort needs to be made to screen patients prior to MR imaging for such contraindications to avoid detrimental results. Also, institutions placing implants (approved and unapproved for MR) should become legally responsible for providing the required information to the patients and their physicians

  15. Cardiac reflections and natural vibrations: Force-frequency relation recording system in the stress echo lab

    Directory of Open Access Journals (Sweden)

    Pianelli Mascia

    2007-11-01

    Full Text Available Abstract Background The inherent ability of ventricular myocardium to increase its force of contraction in response to an increase in contraction frequency is known as the cardiac force-frequency relation (FFR. This relation can be easily obtained in the stress echo lab, where the force is computed as the systolic pressure/end-systolic volume index ratio, and measured for increasing heart rates during stress. Ideally, the noninvasive, imaging independent, objective assessment of FFR would greatly enhance its practical appeal. Objectives 1 – To evaluate the feasibility of the cardiac force measurement by a precordial cutaneous sensor. 2 – To build the curve of force variation as a function of the heart rate. 3 – To compare the standard stress echo results vs. this sensor operator-independent built FFR. Methods The transcutaneous force sensor was positioned in the precordial region in 88 consecutive patients referred for exercise, dipyridamole, or pacing stress. The force was measured as the myocardial vibrations amplitude in the isovolumic contraction period. FFR was computed as the curve of force variation as a function of heart rate. Standard echocardiographic FFR measurements were performed. Results A consistent FFR was obtained in all patients. Both the sensor built and the echo built FFR identifiy pts with normal or abnormal contractile reserve. The best cut-off value of the sensor built FFR was 15.5 g * 10-3 (Sensitivity = 0.85, Specificity = 0.77. Sensor built FFR slope and shape mirror pressure/volume relation during stress. This approach is extendable to daily physiological exercise and could be potentially attractive in home monitoring systems.

  16. Relative potency as a means of evaluating ELF (Extremely Low Frequency) health risks

    Energy Technology Data Exchange (ETDEWEB)

    Easterly, C.E.; Glass, L.R.

    1990-09-01

    In the 1970's, a variety of developments took place to heightened public and scientific interest in electromagnetic fields. During this time, biological studies of nonionizing electromagnetic fields were taking place, but no clear evidence of risks to public health was identified. Then came the surprising epidemiological finding suggesting that 60 Hz magnetic fields may be related to some childhood leukemias. Our particular interest at ORNL was how to interpret the available data with respect to human exposures to the nearly ubiquitous fields. A review of the available data showed that consistent biological effects were difficult to identify. Classical toxicological tests used in chemical risk assessment had not been performed with Extremely Low Frequency (ELF) fields but rather a wide range of mechanistic studies had been pursued. To evaluate the level of anticipated hazard or risk there was neither a mechanistic understanding nor a consistent phenomenological outcome. A risk evaluation normally requires one or the other of these two types of information. Two quite different approaches were pursued: meta-analysis and relative potency. The first of these is a method to combine data from similar experiments to enhance the relative statistical power of a collection of small sample size studies, and will not be discussed further. The second, relative potency, will be the focus of this paper. 20 refs., 2 figs.

  17. Open Photoacoustic Cell for Blood Sugar Measurement: Numerical Calculation of Frequency Response

    CERN Document Server

    Baumann, Bernd; Teschner, Mark

    2015-01-01

    A new approach for continuous and non-invasive monitoring of the glucose concentration in human epidermis has been suggested recently. This method is based on photoacoustic (PA) analysis of human interstitial fluid. The measurement can be performed in vitro and in vivo and, therefore, may form the basis for a non-invasive monitoring of the blood sugar level for diabetes patients. It requires a windowless PA cell with an additional opening that is pressed onto the human skin. Since signals are weak, advantage is taken of acoustic resonances of the cell. Recently, a numerical approach based on the Finite Element (FE) Method has been successfully used for the calculation of the frequency response function of closed PA cells. This method has now been adapted to obtain the frequency response of the open cell. Despite the fact that loss due to sound radiation at the opening is not included, fairly good accordance with measurement is achieved.

  18. A method to measure the frequencies of individual half cells in a dumbbell cavity.

    Science.gov (United States)

    An, Sun; Liping, Zhang; Yazhe, Tang; Li, Ying-min; Cho, Yong-Sub

    2008-10-01

    Dumbbell fabrication is a midprocess for manufacturing an elliptical superconducting rf cavity. In order to understand how a welding shrinkage affects a dumbbell's frequencies and length, we need to measure the exact frequencies of each individual half cell of a dumbbell. To improve such a calculation precision and to simplify the calculation formulae, based on a two-coupled oscillator model and a cavity perturbation theory, a new formula to calculate the individual half-cell frequencies of a dumbbell or the individual cavity frequencies of a two-cavity coupling system has been developed, and its performance has been confirmed by using a dumbbell simulation. This formula can be applied to any kind of rf cavities with electric, magnetic, or electromagnetic coupling, if a coupling hole between two coupling cavities is small compared to the wavelength. Compared to other calculation formulae, this formula simplifies the calculation process of the individual resonator frequencies of a coupling system considerably, and it can also improve the calculation precision than that of a normal calculation method. Another advantage of this new method is that we do not need to consider a coupling factor between two resonators during a testing for an individual resonator frequency of an oscillator. The developed formula has been successfully used to tune the PEFP dumbbells.

  19. A Review of Low Frequency Electromagnetic Wave Phenomena Related to Tropospheric-Ionospheric Coupling Mechanisms

    Science.gov (United States)

    Simoes, Fernando; Pfaff, Robert; Berthelier, Jean-Jacques; Klenzing, Jeffrey

    2012-01-01

    Investigation of coupling mechanisms between the troposphere and the ionosphere requires a multidisciplinary approach involving several branches of atmospheric sciences, from meteorology, atmospheric chemistry, and fulminology to aeronomy, plasma physics, and space weather. In this work, we review low frequency electromagnetic wave propagation in the Earth-ionosphere cavity from a troposphere-ionosphere coupling perspective. We discuss electromagnetic wave generation, propagation, and resonance phenomena, considering atmospheric, ionospheric and magnetospheric sources, from lightning and transient luminous events at low altitude to Alfven waves and particle precipitation related to solar and magnetospheric processes. We review in situ ionospheric processes as well as surface and space weather phenomena that drive troposphere-ionosphere dynamics. Effects of aerosols, water vapor distribution, thermodynamic parameters, and cloud charge separation and electrification processes on atmospheric electricity and electromagnetic waves are reviewed. We also briefly revisit ionospheric irregularities such as spread-F and explosive spread-F, sporadic-E, traveling ionospheric disturbances, Trimpi effect, and hiss and plasma turbulence. Regarding the role of the lower boundary of the cavity, we review transient surface phenomena, including seismic activity, earthquakes, volcanic processes and dust electrification. The role of surface and atmospheric gravity waves in ionospheric dynamics is also briefly addressed. We summarize analytical and numerical tools and techniques to model low frequency electromagnetic wave propagation and solving inverse problems and summarize in a final section a few challenging subjects that are important for a better understanding of tropospheric-ionospheric coupling mechanisms.

  20. Genetic recombination in Escherichia coli : II. Calculation of incorporation frequency and relative map distance by recombinant analysis

    NARCIS (Netherlands)

    Haan, P.G. de; Verhoef, C.

    1966-01-01

    In this paper a mathematical analysis based on the physical exchange of genetic material is presented for a four-factor cross. The incorporation frequency of donor markers and the relative map distances may be accurately estimated from the frequencies of the eight recombinant classes. The results ob

  1. Tracking the Time Course of Word-Frequency Effects in Auditory Word Recognition with Event-Related Potentials

    Science.gov (United States)

    Dufour, Sophie; Brunelliere, Angele; Frauenfelder, Ulrich H.

    2013-01-01

    Although the word-frequency effect is one of the most established findings in spoken-word recognition, the precise processing locus of this effect is still a topic of debate. In this study, we used event-related potentials (ERPs) to track the time course of the word-frequency effect. In addition, the neighborhood density effect, which is known to…

  2. Comparison of dicentrics, micronuclei or apoptosis frequency in V-79 cells after X-irradiation

    International Nuclear Information System (INIS)

    So far, the chromosomal studies are the most established method of biological dosimetry. We compared this method with micronucleus and apoptosis detection method simultaneously in V-79 cells. The frequency of apoptotic cells in low doses (0.1-0.5Gy) are more prominent than two other methods in Vitro. Presumably, apoptosis may be chosen as a preferable alternative biological dosimetry or environmental assessment of biological effects of ionizing radiation. (author)

  3. Relative Frequency of Peptic Ulcer and Erosion in Patients with Different Types of Cholestasis

    Directory of Open Access Journals (Sweden)

    F Joukar

    2008-04-01

    Full Text Available Introduction: Cholestasis is impairment of normal bile excretion into the duodenum and classified as mechanical and non mechanical cholestasis. Mechanical Cholestasis presents with increase in bile duct diameter or obstruction in bile duct in an ERCP. Cholestasis leads to different complications. One of these complications is mucosal peptic erosion leading to gastrointestinal bleeding, perforation and even obstruction due to stricture. We therefore carried out this study to assess the relative frequency of peptic ulcer and erosion in patients with different type of cholestasis. Methods: In a case control study, 170 patients with mechanical cholestasis on the basis of physical examination, liver function tests, radiologic and serologic assay were candidates for ERCP as final therapeutic and diagnostic test. Collected data was registered in questionnaire and evaluated by the Fisher Test. Later, sonography (common bile duct diameter in the two groups: mechanical (85 patients and non mechanical (85 patients and endoscopy was done for exact survey and location of mucosal erosions. Results: Frequency of mucosal peptic erosions in mechanical cholestatic groups was42.6% ( 36 patients and significantly more than frequency of mucosal peptic erosion in non mechanical cholestatic groups (15 patients, 17.6% (P=0.02. 51 patients (30% of the total patients with cholestasis had mucosal erosion. From these patients, 25 patients had peptic ulcer [frequency of duodenal ulcer was 17 patients (68% and gastric ulcer was 8 patients (32% ](P=0.01. There was significant difference in prevalence of duodenal ulcer in patients with mechanical (12 cases, 70.6% and non mechanical (5 cases, 29.4% cholestasis(P=0.01. There was a significant difference between prevalence of duodenal ulcer (12 cases, 70.6% and gastric ulcer(5 cases, 29.4% in patients with mechanical cholestasis (P=0.01 but this was not so in patients with non mechanical cholestasis. Conclusion: According to

  4. Temporalchanges in relative frequencies of third chromosome inversions of Drosophila pseudoobscura in Mexican populations

    Directory of Open Access Journals (Sweden)

    Salceda Victor M.

    2008-01-01

    Full Text Available Variations in relative frequencies of third chromosome inversions during 1974-2000 in three populations of D. pseudoobscura from Mexico were analyzed. The general constitution of these populations is formed from ten up to 15 different inversions, been prevalent, as data shows, the gene arrangements CU, TL, SC, OA, EP, and OL as main components of the studied populations. In Amecameca and Tulancingo we observed that they were constituted by a dominant pair in both cases represented by such partners as CU-TL inside each pair, in Amecameca the superior partner was CU and in Tulancingo TL. In Zirahuén two dominant pairs form the constitution they are SC-OA and CU-TL been the former superior. In all cases sporadic increases of some of inversions were observed. No directional changes were observed. The cyclic pattern is show within periods of 4-5 years.

  5. Load-adaptive frequency reuse scheme for inter-cell interference coordination in relay networks

    Institute of Scientific and Technical Information of China (English)

    CHEN Mu-qiong; JI Hong; LI Xi

    2010-01-01

    Cellular relay networks adopting orthogonal frequency division multiple(OFDM)technology has been widely accepted for next generation wireless communication due to its advantage in enlarging coverage scale as well as improving data rate.In order to improve the performance of user equipments(UEs)near the cell edge,especially to avoid the interference from inter-cell and intra cell,an enhanced soft frequency reuse scheme is adopted in this paper to assure inter-cell interference coordination(ICIC).Compared with traditional frequency allocation work,the proposed scheme is interference-aware and load-adaptive,which dynamically assigns available frequency among UES under certain schedule method in variable traffic load condition and mitigates interference using information provided by interference indicator.It can improve signal-to-interference plus noise ratio(SINR)of the UE in each sub channel thus enable the system achieve better throughput and blocking probability performance.Simulation results prove that the proposed scheme may achieve desirable performance on throughput,blocking probability and spectral utilization in the sector under different traffic load compared with other schemes.

  6. Biological effects of THz electromagnetic waves on frequencies of active cell metabolites at a molecular level

    Directory of Open Access Journals (Sweden)

    Vyacheslav F. Kirichuk

    2013-11-01

    Full Text Available A reaction of biomolecules had been studied, including an effect of albumin molecules on THz electromagnetic waves on frequencies of active cell metabolites (nitrogen oxide 150.176-150.664 GHz and atmospheric oxygen 129.0 GHz. Change of conformational molecule state had been displayed.

  7. Peripheral T-cell lymphoma: Frequency and distribution in a tertiary referral center in South India

    Directory of Open Access Journals (Sweden)

    Deepak K Burad

    2012-01-01

    Full Text Available Background and Aim: Peripheral T/NK-cell lymphomas are uncommon types of non-Hodgkin′s lymphoma (NHL with a higher frequency in Far East countries as compared to the West. This study was undertaken to ascertain the frequency and distribution pattern of peripheral T-cell lymphomas (PTCLs diagnosed in a tertiary care center in South India. Materials and Methods: This retrospective study was carried out in Department of General Pathology, Christian Medical College, Vellore. The time period was for 2 years from 1 st January 2008 till 31st December 2009. All PTCLs were reviewed and classified according to the World Health Organization (WHO 2008 classification. Results: Of a total of 1032 cases of NHL, 180 cases were PTCL, which accounted for 17.4% cases of all the NHLs. Of these, PTCL, not otherwise specified (PTCL, NOS was the most common subtype (48 cases, 26.1%, followed by anaplastic large cell lymphoma (41 cases, 22.8%, mycosis fungoides (21 cases, 11.7%, angioimmunoblastic T-cell lymphoma (16 cases, 8.9%, subcutaneous panniculitis like T-cell lymphoma (15 cases, 8.4%, extranodal NK/T-cell lymphoma, nasal type (12 cases, 6.7%, and hepatosplenic T-cell lymphoma (10 cases, 5.6%. The most common primary site of presentation was nodal accounting for 42% followed by cutaneous (34%, upper aerodigestive sites (8.9%, spleen (6.7%, and gastrointestinal tract (GIT; 3.3%. Conclusions: This is the largest single study on PTCLs in India and we document that its frequency is higher than that reported in Western literature and previous Indian studies and almost similar to that reported in some Far East studies. The frequency of mycosis fungoides, subcutaneous panniculitis like T-cell lymphoma, and hepatosplenic T-cell lymphoma was higher than that reported in the World literature and previous Indian studies. The frequency of extranodal NK/T-cell lymphoma and angioimmunoblastic T-cell lymphoma was much lower than that reported in the Far East literature.

  8. Low frequency variability of Climate-Related-Energy penetration in Europe

    Science.gov (United States)

    Raynaud, Damien; Baptiste, François; Hingray, Benoit; Creutin, Jean-Dominique

    2016-04-01

    The penetration rate of Climate Related Energy sources like solar-power, wind-power and hydro-power source measures the mismatch between the energy availability from those fatal productions and the energy demand which may be also partly dependent on the climate. The penetration rate is a key factor - with potentially large technical and economic implications, to be accounted for in public policies and private initiatives for a massive integration of renewables in the classical energy system. For a given region, it is classically estimated from high resolution time series of energy productions and energy demand derived from times series of their driving climatic variables (temperature, wind, radiation, precipitation). The penetration rate obviously highly depends on the seasonal and also high frequency time variability of these climatic variables (François et al. 2016). A less studied aspect of this penetration rate is its dependence to low frequency variability of climate, from annual to pluriannual time scales. We here explore this dependence for a set of 12 contrasted hydroclimatic regions in Europe with long time series of weather variables reconstructed for the whole 20th century. We discuss the interannual, and interdecadal variability of the penetration rate for the solar-power, wind-power and run-of-the river energy sources taken individually and for different mixes. We discuss how it can be increased / stabilized with local energy storage. Reference : François, B, Hingray, B., Raynaud, R., Borga, M. and Creutin, J.D., 2016. Increasing Climate-Related-Energy penetration by integrating run-of-the river hydropower to wind/solar mix. Renewable Energy. 87(1), pp.686-696. doi:10.1016/j.renene.2015.10.064 This work is part of the COMPLEX Project (European Collaborative Project FP7-ENV-2012 number: 308601; http://www.complex.ac.uk/).

  9. The relative frequencies of causes of widespread ground-glass opacity: A retrospective cohort

    Energy Technology Data Exchange (ETDEWEB)

    Hewitt, Michael G., E-mail: Mike_hewitt@me.com; Miller, Wallace T., E-mail: Wallace.miller@uphs.upenn.edu; Reilly, Thomas J., E-mail: thomasjreilly@comcast.net; Simpson, Scott, E-mail: Simpson80@gmail.com

    2014-10-15

    Highlights: • The most common cause of widespread ground-glass opacities is hydrostatic pulmonary edema. • Associated findings such as air-trapping and centrilobular nodules are highly specific for hypersensitivity pneumonitis. • The clinical setting (outpatient versus inpatient) will alter the order of the differential diagnosis. - Abstract: Purpose: The purpose of our study was to determine the relative frequencies of causes of widespread ground-glass opacity (GGO) in an unselected, consecutive patient population and to identify any associated imaging findings that can narrow or reorganize the differential. Materials and methods: The study was approved by the center's IRB and is HIPPA compliant. Cases with widespread GGO in the radiology report were identified by searching the Radiology Information System. Medical records and CT scan examinations were reviewed for the causes of widespread GGO. Associations between a less dominant imaging finding and a particular diagnosis were analyzed with the chi square test. Our study group consisted of 234 examinations with 124 women and 110 men and a mean age of 53.7 years. Results: A cause was established in 204 (87.2%) cases. Hydrostatic pulmonary edema was most common with 131 cases (56%). Interstitial lung diseases (ILD) were the next most common, most often hypersensitivity pneumonitis (HP) (n = 12, 5%) and connective tissue disease related ILD (n = 7, 3%). Infection accounted for 5% (12 cases). A few miscellaneous diseases accounted for 5 cases (2.1%). The combination of septal thickening and pleural effusions had a specificity of 0.91 for hydrostatic pulmonary edema (P < .001) while centrilobular nodules and air trapping had a specificity of 1.0 for HP. In 24 (10.2%) patients, increased opacification from expiration was incorrectly interpreted as representing widespread ground glass opacity. The relative frequency of disease dramatically changed according to the setting. In the inpatient setting, diffuse

  10. The relative frequencies of causes of widespread ground-glass opacity: A retrospective cohort

    International Nuclear Information System (INIS)

    Highlights: • The most common cause of widespread ground-glass opacities is hydrostatic pulmonary edema. • Associated findings such as air-trapping and centrilobular nodules are highly specific for hypersensitivity pneumonitis. • The clinical setting (outpatient versus inpatient) will alter the order of the differential diagnosis. - Abstract: Purpose: The purpose of our study was to determine the relative frequencies of causes of widespread ground-glass opacity (GGO) in an unselected, consecutive patient population and to identify any associated imaging findings that can narrow or reorganize the differential. Materials and methods: The study was approved by the center's IRB and is HIPPA compliant. Cases with widespread GGO in the radiology report were identified by searching the Radiology Information System. Medical records and CT scan examinations were reviewed for the causes of widespread GGO. Associations between a less dominant imaging finding and a particular diagnosis were analyzed with the chi square test. Our study group consisted of 234 examinations with 124 women and 110 men and a mean age of 53.7 years. Results: A cause was established in 204 (87.2%) cases. Hydrostatic pulmonary edema was most common with 131 cases (56%). Interstitial lung diseases (ILD) were the next most common, most often hypersensitivity pneumonitis (HP) (n = 12, 5%) and connective tissue disease related ILD (n = 7, 3%). Infection accounted for 5% (12 cases). A few miscellaneous diseases accounted for 5 cases (2.1%). The combination of septal thickening and pleural effusions had a specificity of 0.91 for hydrostatic pulmonary edema (P < .001) while centrilobular nodules and air trapping had a specificity of 1.0 for HP. In 24 (10.2%) patients, increased opacification from expiration was incorrectly interpreted as representing widespread ground glass opacity. The relative frequency of disease dramatically changed according to the setting. In the inpatient setting, diffuse

  11. High frequency of circulating ¿d T cells with dominance of the vd1 subset in a healthy population

    DEFF Research Database (Denmark)

    Hviid, L; Akanmori, B D; Loizon, S;

    2000-01-01

    TCR gamma delta(+) cells constitute <5% of all circulating T cells in healthy, adult Caucasians, and V(delta)1(+) cells constitute a minority of these cells. In contrast to TCR alpha beta(+) cells, their repertoire is selected extrathymically by environmental antigens. Although increased frequenc...

  12. Low frequency noise indictor for solar cells quality assessment and reliability prediction

    International Nuclear Information System (INIS)

    In this activity forward and reverse voltage dependence of the noise voltage spectral density for the constant frequency operation mode of a set of mono-crystalline solar cells was obtained at room temperature. The voltage spectral density was estimated across a resistor of 100Ω at a medium frequency of transmission band of 1.0 k Hz. The purpose of this activity is to identify defects and determine the reliability of solar cell or PV converters through electrical noise measurements techniques. The experimental outcome, for the forward bias solar cells operation, exhibited an increase of noise spectral density with increasing the forward bias in a non linear or squared low relationship up to a certain forward bias voltage value. However, for the reverse bias direction, the result showed a noise spectral density increase with increasing reverse voltage in a linear relationship. (author)

  13. THE CHARACTERISTICS OF SWITZERLAND'S ALPINE SKIER'S RELATED TO THE FREQUENCY OF ACCIDENTS

    Directory of Open Access Journals (Sweden)

    Giovanis Vassilis

    2011-11-01

    Full Text Available The aim of this research was to record the characteristics of Switzerland's alpine skier's in relation to the frequency of accidents. The formulation of the cases was based on the following questions: skiers with preparation of their physical fitness before the season and the warming-up before skiing have chances of skiing accidents or injuries? In this research 49 skiers participated (30 men and 19 women. The specimens came by recreational skiers (beginners - advanced and athletes in the following ski resorts in Switzerland: Adelboden, Lenk and San Bernardino. The research material came from analysis of completed questionnaires from 49 Swiss skiers. They have recorded four categories of factors: a individual factors b factors of preparation in the snow in relation to injuries c factors of preparation in dry ground in relation to injuries d factors of injuries. About 1 in 3 Swiss skier respondents had in the past, an accident in alpine skiing. In the Swiss population the number of advanced skiers is overriding, with a few years of training in skiing, however with several days training a year using a ski instructor teacher for warming up and individual form of learning. With regard to injured skiers, athletes are the ones that prevail. The skiers who had prepared themselves with a physical fitness preparation before the winter season had a greater percentage of accidents and injuries, while on the other hand had a reduced rate in relation to injuries or accidents during warm up. Swiss skiers usually had upper limb injuries (sprains and dislocations due to the fall of the skier. It is recommended that research be done with all the factors for the selection of the best methodology, preparation and adjustment of physical ability in the difficult environment of skiing with respect to accidents and injuries.

  14. Effects of Angular Frequency During Clinorotation on Mesenchymal Stem Cell Morphology and Migration

    Science.gov (United States)

    Luna, Carlos; Yew, Alvin G.; Hsieh, Adam H.

    2015-01-01

    Background/Objectives: Ground-based microgravity simulation can reproduce the apparent effects of weightlessness in spaceflight using clinostats that continuously reorient the gravity vector on a specimen, creating a time-averaged nullification of gravity. In this work, we investigated the effects of clinorotation speed on the morphology, cytoarchitecture, and migration behavior of human mesenchymal stem cells (hMSCs). Methods: We compared cell responses at clinorotation speeds of 0, 30, 60, and 75 rpm over 8 hours in a recently developed lab-on-chip-based clinostat system. Time lapse light microscopy was used to visualize changes in cell morphology during and after cessation of clinorotation. Cytoarchitecture was assessed by actin and vinculin staining, and chemotaxis was examined using time lapse light microscopy of cells in NGF (100 ng/ml) gradients. Results: Among clinorotated groups, cell area distributions indicated a greater inhibition of cell spreading with higher angular frequency (p is less than 0.005), though average cell area at 30 rpm after 8 hours became statistically similar to control (p = 0.794). Cells at 75rpm clinorotation remained viable and were able to re-spread after clinorotation. In chemotaxis chambers clinorotation did not alter migration patterns in elongated cells, but most clinorotated cells exhibited cell retraction, which strongly compromised motility.

  15. Frequency and characteristics of acne-related post-inflammatory hyperpigmentation.

    Science.gov (United States)

    Abad-Casintahan, Flordeliz; Chow, Steven Kim Weng; Goh, Chee Leok; Kubba, Raj; Hayashi, Nobukazu; Noppakun, Nopadon; See, JoAnn; Suh, Dae Hun; Xiang, Li Hong Flora; Kang, Sewon

    2016-07-01

    In patients with darker skin types (Fitzpatrick phototypes III-VI), acne is often accompanied by post-inflammatory hyperpigmentation (PIH). Further, acne-related pigmentation can pose a greater concern for the patient than the acne lesions. There has been little formal study of this acne-related PIH. Recently, the Asian Acne Board - an international group of dermatologists with interest in acne research - made a preliminary evaluation of the frequency and characteristics of PIH in seven Asian countries. A total of 324 sequential acne subjects were evaluated for the presence of PIH. The majority (80.2%) of subjects had mild to moderate acne and there were more females than males (63.0% vs 37.0%). In this population of patients consulting a dermatologist for acne, 58.2% (188/324) had PIH. The results also showed that pigmentation problems are often long lasting: at least 1 year for more than half of subjects and 5 years or longer in 22.3%. In accordance with our clinical experience, patients reported that PIH is quite bothersome, often as bothersome or more so than the acne itself and sometimes more problematic. Excoriation was commonly reported by patients, and may represent a modifiable risk factor that could potentially be improved by patient education. PMID:26813513

  16. Frequency and Clinical Correlates of Sleep-Related Problems Among Anxious Youth with Autism Spectrum Disorders.

    Science.gov (United States)

    Nadeau, Joshua M; Arnold, Elysse B; Keene, Amanda C; Collier, Amanda B; Lewin, Adam B; Murphy, Tanya K; Storch, Eric A

    2015-08-01

    Sleep-related problems (SRPs) are common and problematic among anxious youth but have not been investigated in anxious youth with autism spectrum disorder (ASD). Participants were 102 youth (ages 7-16 years) with ASD and comorbid anxiety. Youth and their primary caregiver were administered the Pediatric Anxiety Rating Scale. Parents completed the Multidimensional Anxiety Scale for Children-Parent (MASC-P) Report, Social Responsiveness Scale, and the Child Behavior Checklist (CBCL). A measure of SRPs was created from items from the CBCL and MASC-P. Results suggest SRPs were relatively common among youth with ASD and comorbid anxiety. The number of SRPs endorsed directly associated with parent ratings of social deficits, internalizing and externalizing symptoms, and anxiety symptoms, as well as with clinician-rated anxiety symptoms. Parent-rated internalizing symptoms predicted frequency of SRPs over and above social deficits, externalizing symptoms, and parent- and clinician-rated anxiety symptoms. A subset of 40 participants who completed family-based cognitive-behavioral therapy (CBT) experienced reduced SRPs following treatment. Implications, study limitations, and recommendations for future research are discussed. PMID:25239284

  17. Effect of Radio Frequency Interference (RFI) on the Precision of GPS Relative Positioning

    International Nuclear Information System (INIS)

    The successful of GPS observations are dependent on several factors between satellite vehicles and GPS receivers, where low GPS power levels have led to the threat of radio frequency interference (RFI) on the GPS signals. This study was conducted to evaluate the effect of RFI on the precision of positions of single and dual frequency receivers through relative positioning technique by taking into consideration the radius of GPS receiver from interference source, length of baseline and response of rejection. Several tests were conducted in real environment by simulating the interference signal towards GPS receivers in the nominated GPS L1 and L2 bands. Calculations were made to indentify the distance and interference signal power between interference source and GPS receiver in order to investigate the level of effect. To be able to study this effect on the precision of GPS positions, the 3D residual positions and geometric dilution of precision (GDOP) have been used. The findings of this study have demonstrated that a sufficient time for the GPS receiver to respond in particular interference signal power level and the radius from the interference source were made as compared to previous work. It was also indicated that the residual positions and GDOPs were affected proportionally when nearly to interference source but not similar for both days due to GPS coverage and other probable errors. Therefore, a good investigation on RFI towards GPS signals should be conducted in secured environment which can control the various GPS error parameters in order to obtain a reliable result on this effect

  18. Relative validity and reliability of a food frequency questionnaire in youth with type 1 diabetes

    Science.gov (United States)

    Liese, Angela D.; Crandell, Jamie L.; Tooze, Janet A.; Fangman, Mary T.; Couch, Sarah C.; Merchant, Anwar T.; Bell, Ronny A.; Mayer-Davis, Elizabeth J.

    2015-01-01

    Objective To evaluate the relative validity and reliability of the SEARCH food frequency questionnaire (FFQ) that was modified from the Block Kids Questionnaire. Design Study participants completed the 85-item FFQ twice plus three 24-hour dietary recalls within one month. We estimated correlations between frequencies obtained from participants with true usual intake for food groups and nutrients, using a two-part model for episodically-consumed foods and measurement error adjustment. Setting The multi-center SEARCH for Diabetes in Youth Nutrition Ancillary Study. Subjects A subgroup of 172 participants aged 10 - 24 years with type 1 diabetes. Results The mean correlations adjusted for measurement error of food groups and nutrients between FFQ and true usual intake were 0.41 and 0.38, respectively, with 57% of the food groups and 70% of the nutrients exhibiting correlations >0.35. Correlations were high for low-fat dairy (0.80), sugar-sweetened beverages (0.54), cholesterol (0.59) and saturated fat (0.51), while correlations were poor for high fiber bread and cereal (0.16) and folate (0.11). Reliability of FFQ intake based on two FFQ administrations was also reasonable with 54% of Pearson correlation coefficients ≥ 0.5. Reliability was high for low fat dairy (0.7), vegetables (0.6), carbohydrates, fiber, folate and vitamin C (all 0.5), but less than desirable for low fat poultry and high fiber bread, cereal, rice and pasta (0.2-0.3). Conclusions While there is some room for improvement, our findings suggest that the SEARCH FFQ performs quite well for the assessment of many nutrients and food groups in a sample of youth with type 1 diabetes. PMID:24679679

  19. Experimental studies on ultralow frequency pulsed gradient magnetic field inducing apoptosis of cancer cell and inhibiting growth of cancer cell

    Institute of Scientific and Technical Information of China (English)

    曾繁清; 郑从义; 张新晨; 李宗山; 李朝阳; 王川婴; 张新松; 黄晓玲; 张沪生

    2002-01-01

    The morphology characteristics of cell apoptosis of the malignant tumour cells in magnetic field-treated mouse was observed for the first time. The apoptotic cancer cell contracted, became rounder and divorced from adjacent cells; the heterochromatin condensed and coagulated together along the inner side of the nuclear membrane; the endoplasmic reticulums(ER) expanded and fused with the cellular membrane; many apoptotic bodies which were packed by the cellular membrane appeared and were devoured by some lymphocytes and plasma. Apoptosis of cancer cells was detected by terminal deoxynucleotidyl transferase mediated in situ nick end labeling(TUNEL). It was found that the number of apoptosis cancer cells of the sample treated by the magnetic field is more than that of the control sample. The growth of malignant tumour in mice was inhibited and the ability of immune cell to dissolve cancer cells was improved by ultralow frequency(ULF) pulsed gradient magnetic field; the nuclei DNA contents decreased, indicating that magnetic field can block DNA replication and inhibit mitosis of cancer cells. It was suggested that magnetic field could inhibit the metabolism of cancer cell, lower its malignancy, and restrain its rapid and heteromorphic growth. Since ULF pulsed gradient magnetic field can induce apoptosis of cancer cells and inhibit the growth of malignant tumour, it could be used as a new method to treat cancer.

  20. Increased frequency of Tim-3 expressing T cells is associated with symptomatic West Nile virus infection.

    Directory of Open Access Journals (Sweden)

    Marion C Lanteri

    Full Text Available More than a decade after West Nile virus (WNV entered North America, and despite a significant increase in reported cases during the 2012 and 2013 seasons, no treatment or vaccine for humans is available. Although antiviral T cells contribute to the control of WNV, little is known about their regulation during acute infection. We analyzed the expression of Tim-3 and PD-1, two recently identified T cell negative immune checkpoint receptors, over the course of WNV infection. Symptomatic WNV+ donors exhibited higher frequencies of Tim-3+ cells than asymptomatic subjects within naïve/early differentiated CD28+/-CD57-CD4+ and differentiated CD28-CD57-CD8+ T cells. Our study links Tim-3-expression on T cells during acute WNV infection with the development of symptomatic disease, suggesting Tim-3 and its ligands could be targeted therapeutically to alter anti-WNV immunity and improve disease outcome.

  1. Repeatability and relative validity of a quantitative food-frequency questionnaire among French adults

    Directory of Open Access Journals (Sweden)

    Emmanuel Barrat

    2012-10-01

    Full Text Available Background: A 50-item self-administered food frequency questionnaire (FFQ was developed for French adults, to assess the intake of energy, 10 macronutrients, 11 vitamins, and 11 minerals, and to be used in the context of a medical consultation. Objective: To assess the repeatability and relative validity of this FFQ compared to a 7-day diet record (7-DR. Design: A total of 54 and 100 French adults were included in the repeatability and validation studies, respectively. Repeatability was assessed using two FFQs, the second carried out 3 weeks after the first. In the validation study, subjects first completed the FFQ, then the 7-DR the following week. Energy and nutrient intakes were compared using Pearson correlation. The degree of misclassification by the FFQ, compared to the 7-DR, was calculated by a contingency table of quintiles. Bland–Altman plots assessed the correlation between FFQ and 7-DR across the intake range. Results: Repeatability for intake, explored by Pearson correlation, was 0.62–0.90 (median: 0.81. Relative validity, as determined by Pearson correlation for the nutrient intake derived from the FFQ and 7-DR, was 0.36–0.80 (0.64. The FFQ tended to report higher fiber and micronutrient intake than 7-DR. Misclassification into opposite quintiles ranged 0–6% (1%, whereas classification into same or adjacent quintiles ranged 59–83% (74%. Bland–Altman plots showed good agreement for most nutrients across the range of intake. Conclusion: This new FFQ showed a high repeatability and good relative validity, and thanks to its short length, should be a useful tool for rapidly evaluating the nutrient intake of French adults.

  2. Force control is related to low-frequency oscillations in force and surface EMG.

    Directory of Open Access Journals (Sweden)

    Hwasil Moon

    Full Text Available Force variability during constant force tasks is directly related to oscillations below 0.5 Hz in force. However, it is unknown whether such oscillations exist in muscle activity. The purpose of this paper, therefore, was to determine whether oscillations below 0.5 Hz in force are evident in the activation of muscle. Fourteen young adults (21.07 ± 2.76 years, 7 women performed constant isometric force tasks at 5% and 30% MVC by abducting the left index finger. We recorded the force output from the index finger and surface EMG from the first dorsal interosseous (FDI muscle and quantified the following outcomes: 1 variability of force using the SD of force; 2 power spectrum of force below 2 Hz; 3 EMG bursts; 4 power spectrum of EMG bursts below 2 Hz; and 5 power spectrum of the interference EMG from 10-300 Hz. The SD of force increased significantly from 5 to 30% MVC and this increase was significantly related to the increase in force oscillations below 0.5 Hz (R(2 = 0.82. For both force levels, the power spectrum for force and EMG burst was similar and contained most of the power from 0-0.5 Hz. Force and EMG burst oscillations below 0.5 Hz were highly coherent (coherence = 0.68. The increase in force oscillations below 0.5 Hz from 5 to 30% MVC was related to an increase in EMG burst oscillations below 0.5 Hz (R(2 = 0.51. Finally, there was a strong association between the increase in EMG burst oscillations below 0.5 Hz and the interference EMG from 35-60 Hz (R(2 = 0.95. In conclusion, this finding demonstrates that bursting of the EMG signal contains low-frequency oscillations below 0.5 Hz, which are associated with oscillations in force below 0.5 Hz.

  3. A decreased frequency of regulatory T cells in patients with common variable immunodeficiency.

    Directory of Open Access Journals (Sweden)

    Karina M Melo

    Full Text Available INTRODUCTION: Common variable immunodeficiency disorder (CVID is a heterogeneous syndrome, characterized by deficient antibody production and recurrent bacterial infections in addition abnormalities in T cells. CD4(+CD25(high regulatory T cells (Treg are essential modulators of immune responses, including down-modulation of immune response to pathogens, allergens, cancer cells and self-antigens. OBJECTIVE: In this study we set out to investigate the frequency of Treg cells in CVID patients and correlate with their immune activation status. MATERIALS AND METHODS: Sixteen patients (6 males and 10 females with CVID who had been treated with regular intravenous immunoglobulin and 14 controls were enrolled. Quantitative analyses of peripheral blood mononuclear cells (PBMC were performed by multiparametric flow cytometry using the following cell markers: CD38, HLA-DR, CCR5 (immune activation; CD4, CD25, FOXP3, CD127, and OX40 (Treg cells; Ki-67 and IFN-gamma (intracellular cytokine. RESULTS: A significantly lower proportion of CD4(+CD25(highFOXP3 T cells was observed in CVID patients compared with healthy controls (P<0.05. In addition to a higher proportion of CD8(+ T cells from CVID patients expressing the activation markers, CD38(+ and HLA-DR(+ (P<0.05, we observed no significant correlation between Tregs and immune activation. CONCLUSION: Our results demonstrate that a reduction in Treg cells could have impaired immune function in CVID patients.

  4. The Macro Model of the Inequality Process and the Surging Relative Frequency of Large Wage Incomes

    Science.gov (United States)

    Angle, John

    2008-03-01

    Particles are randomly paired in the Inequality Process (IP), a particle system scattering a positive quantity, wealth. Each particle has a parameter, φ, the fraction of wealth lost in a loss whose probability is 0.5. The stationary distribution of the wealth of particles with φψ is approximated by a γ pdf, the IP's macro model, with shape and scale parameters expressed in terms of φψ. The model's dynamics are driven by the product, φtμt, where φt is the harmonic mean of the φ's in the population at time t and μt, the population mean of wealth at time t. This γ pdf model fits the annual distribution of annual wage income in the U.S. 1961-2003. These data also confirm that the time-series of scalar statistics of wage income that labor economists think are produced by the U.S. distribution of wage income being ``hollowed out'' (bimodal), the increasing dispersion of wage income and the surging relative frequency of large wage incomes, are produced by the distribution being stretched over larger wage incomes, as implied by the IP's macro model when φtμt increases. The IP's macro model includes wage income distribution dynamics into statistical mechanics. To appear in The Econophysics of Markets and Business Networks.

  5. Relative frequencies of constrained events in stochastic processes: An analytical approach.

    Science.gov (United States)

    Rusconi, S; Akhmatskaya, E; Sokolovski, D; Ballard, N; de la Cal, J C

    2015-10-01

    The stochastic simulation algorithm (SSA) and the corresponding Monte Carlo (MC) method are among the most common approaches for studying stochastic processes. They relies on knowledge of interevent probability density functions (PDFs) and on information about dependencies between all possible events. Analytical representations of a PDF are difficult to specify in advance, in many real life applications. Knowing the shapes of PDFs, and using experimental data, different optimization schemes can be applied in order to evaluate probability density functions and, therefore, the properties of the studied system. Such methods, however, are computationally demanding, and often not feasible. We show that, in the case where experimentally accessed properties are directly related to the frequencies of events involved, it may be possible to replace the heavy Monte Carlo core of optimization schemes with an analytical solution. Such a replacement not only provides a more accurate estimation of the properties of the process, but also reduces the simulation time by a factor of order of the sample size (at least ≈10(4)). The proposed analytical approach is valid for any choice of PDF. The accuracy, computational efficiency, and advantages of the method over MC procedures are demonstrated in the exactly solvable case and in the evaluation of branching fractions in controlled radical polymerization (CRP) of acrylic monomers. This polymerization can be modeled by a constrained stochastic process. Constrained systems are quite common, and this makes the method useful for various applications. PMID:26565363

  6. Low-frequency wave activity related to dipolarization fronts detected by MMS in the magnetotail

    Science.gov (United States)

    Le Contel, O.; Retino, A.; Breuillard, H.; Mirioni, L.; Roux, A.; Chust, T.; Chasapis, A.; Lavraud, B.; Lindqvist, P. A.; Khotyaintsev, Y. V.; Vaivads, A.; Fu, H.; Marklund, G. T.; Nakamura, R.; Burch, J. L.; Torbert, R. B.; Moore, T. E.; Ergun, R.; Goodrich, K.; Needell, J.; Chutter, M.; Rau, D.; Dors, I.; Russell, C. T.; Magnes, W.; Strangeway, R. J.; Le, G.; Bromund, K. R.; Plaschke, F.; Fischer, D.; Leinweber, H. K.; Anderson, B. J.; Argall, M. R.; Slavin, J. A.; Kepko, L.; Baumjohann, W.; Pollock, C. J.; Mauk, B.; Fuselier, S. A.

    2015-12-01

    Dipolarization fronts are often associated to reconnection jets in the magnetotail current sheet and are sites of important energy dissipation and particle energization. Since the launch on March 12th and until the 9th of July 2015, the MMS constellation has been moving from dawn to dusk in a string of pearls formation. Although particle instruments were rarely operating and only FIELDS instrument suite was often gathering data, the MMS spacecraft have detected numerous dipolarization fronts, in particular on May 15th. Since 9th of July, the MMS evolved into a tetrahedral configuration with an average inter-satellite distance of 160 km and was still able to detect dipolarization fronts in the dusk magnetotail. As the Larmor radius of thermal protons is about 500 km in this region and dipolarization fronts have a typical thickness of the order of the Larmor radius, such a separation allows us to investigate in detail the microphysics of dipolarization fronts. In this study, we focus in particular on low-frequency electromagnetic wave activity related to the fronts and discuss possible mechanisms of particle heating and acceleration both at large scales (string of pearls configuration) and at kinetic scales (tetrahedral configuration).

  7. The Effects of Weak Combined Magnetic Field on Cell Wall Regeneration and Frequency of Plant Protoplasts Fusion

    Science.gov (United States)

    Nedukha, Olena

    The major purpose of these experiments was to investigate plant protoplast fusion frequency and regeneration of a cell wall by protoplasts at weak combined magnetic field (CMF) with the frequency resonance to the cyclotron frequency of Mg2+, Ca2+ and K+ ions. The protoplasts were isolated from Nicotiana lumbaginifolia and N. silvestris leaf mesophyll and from callus tissues (Nicotiana tabacum and Glycine max). The special extra apparatus with ferromagnetic shield was used for estimate of CMF with the frequency resonance to the cyclotron frequency of Mg2+, Ca2+ and K+ ions. The fusion of protoplasts is realized by using of parent protoplasts isolated from one plant species, as well as from various plant species. Control samples were situated near the apparatus with CMF. The laser confocal microscopy was used for study of cell wall regeneration by single and fused protoplasts. The cytochemical methods with DAPI and calcofluor dye were also applied as the detectors for protoplast fusion and regeneration of cell wall. We have been established that CMF with frequency adjusted to the cyclotron frequency Mg2+ ions have shown the most positive influence on regeneration of cell wall by protoplasts. CMF adjusted to the cyclotron frequency of K+ ions very weakly affected on the frequency of protoplast fusion. Largest frequency of protoplasts fusion is noted in the CMF adjusted to the cyclotron frequency of Ca2+ in comparison with the control samples.

  8. Differential Frequency of CD8+ T Cell Subsets in Multiple Sclerosis Patients with Various Clinical Patterns.

    Science.gov (United States)

    Salehi, Zahra; Doosti, Rozita; Beheshti, Masoumeh; Janzamin, Ehsan; Sahraian, Mohammad Ali; Izad, Maryam

    2016-01-01

    Recent evidence points to a pathogenic role for CD8+ cytotoxic T (Tc) cells in Multiple sclerosis (MS). Based on cytokine profile, Tc cells can be divided into different subsets: IFN-γ (Tc1), IL-4 (Tc2), IL-10 (Tc10), IL-17 (Tc17), IL-21 (Tc21), IL-22 (Tc22) and TNF-α producing cells. In this study we evaluated the frequency of Tc cell subsets and the serum level of Tc17 differentiation cytokines in MS patients with different clinical patterns. We analyzed Tc cell subsets percentage in peripheral blood of relapsing-remitting (RRMS) (n = 28), secondary-progressive (SPMS) (n = 10) and primary-progressive (PPMS) (n = 4) MS patients in comparison to healthy controls (n = 15) using flow cytometry. Serum level of TGF-β, IL-6 and IL-23 were measured by ELISA. We showed elevated levels of Tc1 and Tc17 cells in SPMS and RRMS patients in relapse phase, respectively (P = 0.04). Interestingly, the percentage of TNF-α producing CD8+ T cells in relapse and remission phase of RRMS and SPMS patients were higher than controls (P = 0.01, P = 0.004, P = 0.01, respectively) and Tc21 increased in remission phase of RRMS compared to SPMS (P = 0.03). We also found higher frequency of CD8+ IFN-γ+ TNF-α+ IL-17+ T cells in relapse phase of RRMS compared to remission phase, SPMS patients and controls (P = 0.01, P = 0.004 and P = 0.02, respectively). TGF- β increased in sera of RRMS patients in remission phase (P = 0.03) and SPMS (P = 0.05) compared to healthy subjects. Increased level of Tc17 and CD8+ IFN-γ+ TNF-α+ IL-17+ T cells in relapse phase highlights the critical role of IL-17 in RRMS pathogenesis. PMID:27467597

  9. Frequency of islet cell autoantibodies (IA-2 and GAD in young Brazilian type 1 diabetes patients

    Directory of Open Access Journals (Sweden)

    V.C. Pardini

    1999-10-01

    Full Text Available Type 1 diabetes, as an autoimmune disease, presents several islet cell-specific autoantibodies such as islet cell antibody (ICA, anti-insulin, anti-glutamic acid decarboxylase (GAD and the antibody (Ab against tyrosine phosphatase (PTP-like protein known as ICA-512 (IA-2. In order to determine the frequency of the anti-GAD and anti-IA-2 autoantibodies in Brazilian type 1 diabetes patients we studied 35 diabetes mellitus (DM type 1 patients with recent-onset disease (£12 months and 37 type 1 diabetes patients with long-duration diabetes (>12 months who were compared to 12 children with normal fasting glucose. Anti-GAD65 and anti-IA-2 autoantibodies were detected with commercial immunoprecipitation assays. The frequency of positive results in recent-onset DM type 1 patients was 80.0% for GADAb, 62.9% for IA-2Ab and 82.9% for GADAb and/or IA-2Ab. The long-duration type 1 diabetes subjects presented frequencies of 54.1% for GADAb and IA-2Ab, and 67.5% for GAD and/or IA-2 antibodies. The control group showed no positive cases. Anti-GAD and IA-2 assays showed a high frequency of positivity in these Brazilian type 1 diabetes patients, who presented the same prevalence as a Caucasian population.

  10. Frequency of Werner helicase 1367 polymorphism and age-related morbidity in an elderly Brazilian population

    Directory of Open Access Journals (Sweden)

    M.A.C. Smith

    2005-07-01

    Full Text Available Werner syndrome (WS is a premature aging disease caused by a mutation in the WRN gene. The gene was identified in 1996 and its product acts as a DNA helicase and exonuclease. Some specific WRN polymorphic variants were associated with increased risk for cardiovascular diseases. The identification of genetic polymorphisms as risk factors for complex diseases affecting older people can improve their prevention, diagnosis and prognosis. We investigated WRN codon 1367 polymorphism in 383 residents in a district of the city of São Paulo, who were enrolled in an Elderly Brazilian Longitudinal Study. Their mean age was 79.70 ± 5.32 years, ranging from 67 to 97. This population was composed of 262 females (68.4% and 121 males (31.6% of European (89.2%, Japanese (3.3%, Middle Eastern (1.81%, and mixed and/or other origins (5.7%. There are no studies concerning this polymorphism in Brazilian population. These subjects were evaluated clinically every two years. The major health problems and morbidities affecting this cohort were cardiovascular diseases (21.7%, hypertension (83.7%, diabetes (63.3%, obesity (41.23%, dementia (8.0%, depression (20.0%, and neoplasia (10.8%. Their prevalence is similar to some urban elderly Brazilian samples. DNA was isolated from blood cells, amplified by PCR and digested with PmaCI. Allele frequencies were 0.788 for the cysteine and 0.211 for the arginine. Genotype distributions were within that expected for the Hardy-Weinberg equilibrium. Female gender was associated with hypertension and obesity. Logistic regression analysis did not detect significant association between the polymorphism and morbidity. These findings confirm those from Europeans and differ from Japanese population.

  11. Cell growth characteristics, differentiation frequency, and immunophenotype of adult ear mesenchymal stem cells.

    Science.gov (United States)

    Staszkiewicz, Jaroslaw; Frazier, Trivia P; Rowan, Brian G; Bunnell, Bruce A; Chiu, Ernest S; Gimble, Jeffrey M; Gawronska-Kozak, Barbara

    2010-01-01

    Ear mesenchymal stem cells (EMSCs) represent a readily accessible population of stem-like cells that are adherent, clonogenic, and have the ability to self-renew. Previously, we have demonstrated that they can be induced to differentiate into adipocyte, osteocyte, chondrocyte, and myocyte lineages. The purpose of the current study was to characterize the growth kinetics of the cells and to determine their ability to form colonies of fibroblasts, adipocytes, osteocytes, and chondrocytes. In addition, the immunophenotypes of freshly isolated and culture-expanded cells were evaluated. From 1 g of tissue, we were able to isolate an average of 7.8 x 10(6) cells exhibiting a cell cycle length of approximately 2-3 days. Colony-forming unit (CFU) assays indicated high proliferation potential, and confirmed previously observed multipotentiality of the cells. Fluorescence-activated cell sorting (FACS) showed that EMSCs were negative for hematopoietic markers (CD4, CD45), proving that they did not derive from circulating hematopoietic cells. The FACS analyses also showed high expression of stem cell antigen-1 (Sca-1) with only a minor population of cells expressing CD117, thus identifying Sca-1 as the more robust stem cell biomarker. Additionally, flow cytometry data revealed that the expression patterns of hematopoietic, stromal, and stem cell markers were maintained in the passaged EMSCs, consistent with the persistence of an undifferentiated state. This study indicates that EMSCs provide an alternative model for in vitro analyses of adult mesenchymal stem cells (MSCs). Further studies will be necessary to determine their utility for tissue engineering and regenerative medical applications. PMID:19400629

  12. Relative Validity of Three Food Frequency Questionnaires for Assessing Dietary Intakes of Guatemalan Schoolchildren.

    Directory of Open Access Journals (Sweden)

    Jessica Marcinkevage

    Full Text Available To determine the relative validity of three food frequency questionnaires (FFQs compared with results from 24-hour dietary recalls for measuring dietary intakes in Guatemalan schoolchildren.A cross-sectional study of primary caregivers (mothers or grandmothers of 6-11 year-old children. Caregivers completed one of three constructed FFQs to measure the child's dietary consumption in the last week: FFQ1 did not incorporate portion sizes; FFQ2 provided portion sizes; and FFQ3 incorporated pictures of median portion sizes. During the same week, each caregiver also completed three 24-hour dietary recalls. Results from the FFQ were compared with corresponding results from the 24-hour dietary recalls.Santa Catarina Pinula, peri-urban Guatemala City.Caregivers (n = 145 of 6-11 year-old children: 46 completed FFQ1, 49 completed FFQ2, and 50 completed FFQ3.The mean values for all nutrients obtained from the 24-hour dietary recall were lower than for those obtained from the FFQs, excluding folic acid in FFQ3, cholesterol and zinc in FFQ2, and cholesterol, folic acid, magnesium, potassium, sodium, and zinc in FFQ1. Energy-adjusted Pearson correlation coefficients ranged from 0.07 (protein to 0.54 (cholesterol for FFQ1 and from 0.05 to 0.74 for FFQ2 and FFQ3. Agreement by both methods (FFQ and 24-hour dietary recalls of classifying children into the same or adjacent quartiles of energy-adjusted nutrient consumption ranged from 62.0% for cholesterol to 95.9% for vitamin B12 across all three FFQs.Our FFQs had moderate to good relative validity in measuring energy and nutrient intakes for 6-11 year-old Guatemalan children. More evidence is needed to evaluate their reproducibility and applicability in similar populations.

  13. Relative validity and reliability of a quantitative food frequency questionnaire for adults in Guam

    Directory of Open Access Journals (Sweden)

    Rachael T. Leon Guerrero

    2015-05-01

    Full Text Available Background: Guam is a US territory in the western Pacific with a diverse population that includes understudied ethnic groups such as Chamorros and Filipinos. A food frequency questionnaire (FFQ to estimate dietary intake was needed to facilitate studies of diet and health among adults living in Guam. Objective: To develop and validate an FFQ to assess dietary intake over a 1-year period among adult Guam residents. Design: A three-part study was conducted: 1 an initial cross-sectional study using 24-h recalls to identify a food and beverage list for the FFQ and resulting in a final FFQ containing 142 food and drink items; 2 to test reliability, 56 different individuals completed the FFQ twice; and 3 to test relative validity, self-administered FFQs and up to 2 days of food record data from an additional 109 individuals were collected, and daily nutrient intake from the two methods was compared. Results: The reliability of the FFQ was very good (ρ range=0.65–0.75, and the relative validity of the FFQ was good for women (median Spearman's correlation [ρ] between instruments of 0.45 across 20 nutrients and an interquartile range [IQR] of 0.42–0.58 and generally adequate for men (median ρ=0.31, IQR=0.23–0.55. Validity was also good for Chamorros (median ρ=0.47, IQR=0.38–0.53 and generally adequate for Filipinos (median ρ=0.42, IQR=0.20–0.62. Correlations after energy adjustment were lower (overall median ρ=0.20, IQR=0.14–0.26. Conclusions: The FFQ can be used to rank nutrient intake for adults in Guam and may be helpful in the analysis of relationships between diet and chronic disease in Guam.

  14. Relative validation of a food frequency questionnaire for national health and nutrition monitoring

    Directory of Open Access Journals (Sweden)

    Haftenberger Marjolein

    2010-09-01

    Full Text Available Abstract Background Validation of a food frequency questionnaire (FFQ is important as incorrect information may lead to biased associations. Therefore the relative validity of an FFQ developed for use in the German Health Examination Survey for Adults 2008-2011 (DEGS was examined. Methods Cross-sectional comparisons of food consumption data from the FFQ and from two 24-hour recalls were made in a sample of 161 participants (aged 18 to 80 years of an ongoing nationwide survey, the German National Nutrition Monitoring (NEMONIT. The data collection took place from November 2008 to April 2009. Results Spearman rank correlations between the FFQ and the 24-hour dietary recalls ranged from 0.15 for pizza to 0.80 for tea, with two third of the correlation coefficients exceeding 0.30. All correlation coefficients were statistically significant except those for pizza and cooked vegetables. The proportion of participants classified into the same or adjacent quartile of intake assessed by both methods varied between 68% for cooked vegetables and 94% for coffee. There were no statistically significant differences in food consumption estimates between both methods for 38% of the food groups. For the other food groups, the estimates of food consumption by the FFQ were not generally higher or lower than estimates from the 24-hour dietary recalls. Conclusions The FFQ appears to be reasonably valid in the assessment of food consumption of German adults. For some food groups, such as raw and cooked vegetables, relative risks estimates should be interpreted with caution because of the poor ranking agreement.

  15. Radio-frequency Electrometry Using Rydberg Atoms in Vapor Cells: Towards the Shot Noise Limit

    Science.gov (United States)

    Kumar, Santosh; Fan, Haoquan; Jahangiri, Akbar; Kuebler, Harald; Shaffer, James P.; 5. Physikalisches Institut, Universitat Stuttgart, Germany Collaboration

    2016-05-01

    Rydberg atoms are a promising candidate for radio frequency (RF) electric field sensing. Our method uses electromagnetically induced transparency with Rydberg atoms in vapor cells to read out the effect that the RF electric field has on the Rydberg atoms. The method has the potential for high sensitivity (pV cm-1 Hz- 1 / 2) and can be self-calibrated. Some of the main factors limiting the sensitivity of RF electric field sensing from reaching the shot noise limit are the residual Doppler effect and the sensitivity of the optical read-out using the probe laser. We present progress on overcoming the residual Doppler effect by using a new multi-photon scheme and reaching the shot noise detection limit using frequency modulated spectroscopy. Our experiments also show promise for studying quantum optical effects such as superradiance in vapor cells using Rydberg atoms. This work is supported by DARPA, ARO, and NRO.

  16. Dispersion and Frequency: Is There Any Difference as Regards Their Relation to L2 Vocabulary Gains?

    Science.gov (United States)

    Alcaraz-Mármol, Gema

    2015-01-01

    Despite the current importance given to L2 vocabulary acquisition in the last two decades, considerable deficiencies are found in L2 students' vocabulary size. One of the aspects that may influence vocabulary learning is word frequency. However, scholars warn that frequency may lead to wrong conclusions if the way words are distributed is ignored.…

  17. Effects of weak nonlinearity on dispersion relations and frequency band-gaps of periodic structures

    DEFF Research Database (Denmark)

    Sorokin, Vladislav; Thomsen, Jon Juel

    2015-01-01

    The analysis of the behaviour of linear periodic structures can be traced back over 300 years, to Sir Isaac Newton, and still attracts much attention. An essential feature of periodic struc-tures is the presence of frequency band-gaps, i.e. frequency ranges in which waves cannot propagate...

  18. A broadband chip-scale optical frequency synthesizer at 2.7 × 10(-16) relative uncertainty.

    Science.gov (United States)

    Huang, Shu-Wei; Yang, Jinghui; Yu, Mingbin; McGuyer, Bart H; Kwong, Dim-Lee; Zelevinsky, Tanya; Wong, Chee Wei

    2016-04-01

    Optical frequency combs-coherent light sources that connect optical frequencies with microwave oscillations-have become the enabling tool for precision spectroscopy, optical clockwork, and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but Kerr nonlinear dynamics in high-Q solid-state microresonators has recently demonstrated promising features as alternative platforms. The advance not only fosters studies of chip-scale frequency metrology but also extends the realm of optical frequency combs. We report the full stabilization of chip-scale optical frequency combs. The microcomb's two degrees of freedom, one of the comb lines and the native 18-GHz comb spacing, are simultaneously phase-locked to known optical and microwave references. Active comb spacing stabilization improves long-term stability by six orders of magnitude, reaching a record instrument-limited residual instability of [Formula: see text]. Comparing 46 nitride frequency comb lines with a fiber laser frequency comb, we demonstrate the unprecedented microcomb tooth-to-tooth relative frequency uncertainty down to 50 mHz and 2.7 × 10(-16), heralding novel solid-state applications in precision spectroscopy, coherent communications, and astronomical spectrography.

  19. A broadband chip-scale optical frequency synthesizer at 2.7 × 10(-16) relative uncertainty.

    Science.gov (United States)

    Huang, Shu-Wei; Yang, Jinghui; Yu, Mingbin; McGuyer, Bart H; Kwong, Dim-Lee; Zelevinsky, Tanya; Wong, Chee Wei

    2016-04-01

    Optical frequency combs-coherent light sources that connect optical frequencies with microwave oscillations-have become the enabling tool for precision spectroscopy, optical clockwork, and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but Kerr nonlinear dynamics in high-Q solid-state microresonators has recently demonstrated promising features as alternative platforms. The advance not only fosters studies of chip-scale frequency metrology but also extends the realm of optical frequency combs. We report the full stabilization of chip-scale optical frequency combs. The microcomb's two degrees of freedom, one of the comb lines and the native 18-GHz comb spacing, are simultaneously phase-locked to known optical and microwave references. Active comb spacing stabilization improves long-term stability by six orders of magnitude, reaching a record instrument-limited residual instability of [Formula: see text]. Comparing 46 nitride frequency comb lines with a fiber laser frequency comb, we demonstrate the unprecedented microcomb tooth-to-tooth relative frequency uncertainty down to 50 mHz and 2.7 × 10(-16), heralding novel solid-state applications in precision spectroscopy, coherent communications, and astronomical spectrography. PMID:27152341

  20. A broadband chip-scale optical frequency synthesizer at 2.7 × 10−16 relative uncertainty

    Science.gov (United States)

    Huang, Shu-Wei; Yang, Jinghui; Yu, Mingbin; McGuyer, Bart H.; Kwong, Dim-Lee; Zelevinsky, Tanya; Wong, Chee Wei

    2016-01-01

    Optical frequency combs—coherent light sources that connect optical frequencies with microwave oscillations—have become the enabling tool for precision spectroscopy, optical clockwork, and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but Kerr nonlinear dynamics in high-Q solid-state microresonators has recently demonstrated promising features as alternative platforms. The advance not only fosters studies of chip-scale frequency metrology but also extends the realm of optical frequency combs. We report the full stabilization of chip-scale optical frequency combs. The microcomb’s two degrees of freedom, one of the comb lines and the native 18-GHz comb spacing, are simultaneously phase-locked to known optical and microwave references. Active comb spacing stabilization improves long-term stability by six orders of magnitude, reaching a record instrument-limited residual instability of 3.6mHz/τ. Comparing 46 nitride frequency comb lines with a fiber laser frequency comb, we demonstrate the unprecedented microcomb tooth-to-tooth relative frequency uncertainty down to 50 mHz and 2.7 × 10−16, heralding novel solid-state applications in precision spectroscopy, coherent communications, and astronomical spectrography. PMID:27152341

  1. Sheath-wave-related resonances in the frequency response of a cylindrical monopole in a plasma

    International Nuclear Information System (INIS)

    A floating or negatively biased antenna immersed in a plasma is surrounded by an ion sheath. The antenna-sheath-plasma system may support slow surface waves at driving frequencies below the electron plasma frequency. Resonances associated with these so-called sheath waves are observed at certain frequencies in the antenna's response to an applied sinusoidal signal. A detailed experimental study of these resonances is presented here for a short cylindrical monopole in a low-pressure isotropic argon plasma. The effect on the resonance frequencies of a dc bias applied to the antenna and of plasma density and antenna length was investigated. Good agreement was obtained with the theoretical predictions derived from a known dispersion equation for sheath waves. From the experimental data, the relationship between sheath thickness and antenna potential, and the frequency dependence of the antenna admittance could be derived

  2. Frequency of micronucleus in oral epithelial cells after exposure to mate-tea in healthy humans

    OpenAIRE

    Bortoluzzi, Marcelo Carlos; Campagnoli, Eduardo-Baulm; Milan, José-Ricaon; Reinheimer, Angélica; Masson, Maicon; Capella, Diogo-Lenzi

    2014-01-01

    Objectives: The aim of this study was to evaluate the possibility of technique simplification for cytology slides in order to evaluate the frequency of micronuclei (FMic) and conduct a experiment looking to know the FMic of oral epithelial cells of healthy volunteers exposed to mate tea (Ilex paraguarariensis). Material and Methods: This is a laboratorial and nonrandomized trial (quasi-experiment), where the nonusers subjects were exposed to mate-tea, consumed in the traditional way, two drin...

  3. Frequency of red cell, leukocytic and platelet alloantibodies in patients with hematological diseases

    OpenAIRE

    N. V. Mineeva; S. V. Gavrovskaya; I. I. Krobinets; I. A. Pashkova; N. N. Bodrova; E. A. Sysoeva

    2013-01-01

    History of multiple transfusions in patients with hematological diseases increases the likelihood of immunization to donor blood cells antigensand immunological complications development. Incidence of alloantibodies development in this patients was assessed in this work. Alloantibodies detection was performed in patients with aplastic anemia, acute leukemia, chronic lymphocytic leukemia, and autoimmune thrombocytopenia. 9696 patients were included in this study. Frequency of alloantibodies to...

  4. An association, in adult Japanese, between the occurrence of rogue cells among cultured lymphocytes (JC virus activity) and the frequency of simple chromosomal damage among the lymphocytes of persons exhibiting these rogue cells

    Energy Technology Data Exchange (ETDEWEB)

    Neel, J.V. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Human Genetics

    1998-08-01

    Data from a previous study of the cytogenetic effects, in cultured lymphocytes, of exposure to the atomic bomb in Hiroshima have been reanalyzed to determine the relationship between the occurrence of rogue cells in an individual and the frequency of simple chromosomal damage in the nonrogue cells of the same individual. Rogue cells are cells with complex chromosomal damage, currently believed to be a manifestation of the activity of a human polyoma virus termed JC. Among a total of 1,835 persons examined, there were 45 exhibiting rogue cells. A total of 179,599 cells were scored for simple chromosomal damage. In both the exposed and the control populations, there was an absolute increase of {approximately}1.5% in the frequency of simple chromosomal damage in the nonrogue cells of those exhibiting rogue cells, when compared with the frequencies observed in those not exhibiting rogue cells, which is a statistically significant difference. It is argued that this phenomenon, occurring not only in lymphocytes but possibly also in other cells/tissues, may play a contributory role in the origin of malignancies characterized by clonal chromosome abnormalities. Unexpectedly, among those exhibiting rogue cells, there was a disproportionately greater representation of persons who had received relatively high radiation exposures from the bomb. The reason for this is unclear, but it is tempting to relate the finding to some lingering effect of the exposure (or the circumstances surrounding the exposure) on immunocompetence.

  5. Frequency of cell treatment with cold microwave argon plasma is important for the final outcome

    Science.gov (United States)

    Sysolyatina, E.; Vasiliev, M.; Kurnaeva, M.; Kornienko, I.; Petrov, O.; Fortov, V.; Gintsburg, A.; Petersen, E.; Ermolaeva, S.

    2016-07-01

    The purpose of this work was to establish the influence of a regime of cold microwave argon plasma treatments on the physiological characteristics of human fibroblasts and keratinocytes. We used three regimes of plasma application: a single treatment, double treatment with a 48 h interval, and daily treatments for 3 d. Cell proliferation after plasma application was quantified in real time, and immunohistochemistry was used to establish the viability of the cells and determine changes in their physiology. It was established that the frequency of cell treatments is important for the outcome. In the samples treated with single plasma application and double plasma applications with a 48 h interval, a 42.6% and 32.0% increase was observed in the number of cells, respectively. In addition, there were no signs of deoxyribonucleic acid breaks immediately after plasma application. In contrast, plasma application increased the accumulation of cells in the active phases of the cell cycle. The activation of proliferation correlated with a decrease in the level of β-galactosidase, a senescence marker. This could be due to cell renovation after plasma application. Daily treatment decreased cell proliferation up to 29.1% in comparison with the control after 3 d.

  6. The influence of the relative phase between the driving voltages on electron heating in asymmetric dual frequency capacitive discharges

    International Nuclear Information System (INIS)

    The influence of the relative phase between the driving voltages on electron heating in asymmetric phase-locked dual frequency capacitively coupled radio frequency plasmas operated at 2 and 14 MHz is investigated. The basis of the analysis is a nonlinear global model with the option to implement a relative phase between the two driving voltages. In recent publications it has been reported that nonlinear electron resonance heating can drastically enhance the power dissipation to electrons at moments of sheath collapse due to the self-excitation of nonlinear plasma series resonance (PSR) oscillations of the radio frequency current. This work shows that depending on the relative phase of the driving voltages, the total number and exact moments of sheath collapse can be influenced. In the case of two consecutive sheath collapses a substantial increase in dissipated power compared with the known increase due to a single PSR excitation event per period is observed. Phase resolved optical emission spectroscopy (PROES) provides access to the excitation dynamics in front of the driven electrode. Via PROES the propagation of beam-like energetic electrons immediately after the sheath collapse is observed. In this work we demonstrate that there is a close relation between moments of sheath collapse, and thus excitation of the PSR, and beam-like electron propagation. A comparison of simulation results to experiments in a single and dual frequency discharge shows good agreement. In particular the observed influence of the relative phase on the dynamics of a dual frequency discharge is described by means of the presented model. Additionally, the analysis demonstrates that the observed gain in dissipation is not accompanied by an increase in the electrode's dc-bias voltage which directly addresses the issue of separate control of ion flux and ion energy in dual frequency capacitively coupled radio frequency plasmas.

  7. Increased frequency of CD4 and CD8 regulatory T cells in individuals under 15 years with multibacillary leprosy.

    Directory of Open Access Journals (Sweden)

    Camila Fernandes

    Full Text Available BACKGROUND: Leprosy is a chronic disease, caused by Mycobacterium leprae, which poses a serious public health problem worldwide. Its high incidence in people under 15 years old in Ceará state, Brazil, reflects the difficulty of its control. The spectrum of clinical manifestations is associated with the immune response developed, with the Th1 and Th2 responses being related to the paucibacillary and multibacillary forms, respectively. Regulatory T cells (Treg, which can suppress Th1 and Th2 response, have received special attention in the literature and have been associated with development of chronic infections. However, their role in leprosy in individuals under 15 years old has not yet been elucidated. We evaluated the frequency of CD4(+/CD8(+CD25(highFOXP3(+ and CD4(+/CD8(+CD25(highFOXP3(high cells in leprosy patients and household contacts, in both cases under 15 years old. METHODOLOGY/PRINCIPAL FINDINGS: PBMC from 12 patients and 17 contacts were cultured for 72 hours with anti-CD3 and anti-CD28 (activators or with activators associated with total sonicated fraction of M. leprae. After culture, the frequency of CD4(+/CD8(+ Treg was identified by flow cytometry. Cells stimulated by activators and antigen from multibacillary patients showed Treg frequencies almost two times that of the contacts: CD4(+FOXP3(+ (21.93±8.43 vs. 13.79±8.19%, p = 0.0500, CD4(+FOXP3(high (10.33±5.69 vs. 5.57±4.03%, p = 0.0362, CD8(+FOXP3(+ (13.88±9.19 vs. 6.18±5.56%, p = 0.0230 and CD8(+FOXP3(high (5.36±4.17 vs. 2.23±2.68%, p = 0.0461. Furthermore, the mean fluorescence intensity of FOXP3 in Treg was higher in multibacillary patients than in the contacts. Interestingly, there was a positive correlation of the bacillary index and number of lesions with the frequency of all Treg evaluated in patients. CONCLUSIONS/SIGNIFICANCE: We have demonstrated for the first time that multibacillary leprosy patients under 15 years old have greater CD4(+ and

  8. Reduced cilia frequencies in human renal cell carcinomas versus neighboring parenchymal tissue

    Directory of Open Access Journals (Sweden)

    Basten Sander G

    2013-01-01

    Full Text Available Abstract Background Cilia are essential organelles in multiple organ systems, including the kidney where they serve as important regulators of renal homeostasis. Renal nephron cilia emanate from the apical membrane of epithelia, extending into the lumen where they function in flow-sensing and ligand-dependent signaling cascades. Ciliary dysfunction underlies renal cyst formation that is in part caused by deregulation of planar cell polarity and canonical Wnt signaling. Renal cancer pathologies occur sporadically or in heritable syndromes caused by germline mutations in tumor suppressor genes including VHL. Importantly, Von Hippel-Lindau (VHL patients frequently develop complex renal cysts that can be considered a premalignant stage. One of the well-characterized molecular functions of VHL is its requirement for the maintenance of cilia. In this study, tissue from 110 renal cancer patients who underwent nephrectomy was analyzed to determine if lower ciliary frequency is a common hallmark of renal tumorigenesis by comparing cilia frequencies in both tumor and adjacent parenchymal tissue biopsies from the same kidney. Methods We stained sections of human renal material using markers for cilia. Preliminary staining was performed using an immunofluorescent approach and a combination of acetylated-α-tubulin and pericentrin antibodies and DAPI. After validation of an alternative, higher throughput approach using acetylated-α-tubulin immunohistochemistry, we continued to manually quantify cilia in all tissues. Nuclei were separately counted in an automated fashion in order to determine ciliary frequencies. Similar staining and scoring for Ki67 positive cells was performed to exclude that proliferation obscures cilia formation potential. Results Samples from renal cell carcinoma patients deposited in our hospital tissue bank were previously used to compose a tissue microarray containing three cores of both tumor and parenchymal tissue per patient

  9. Mapping power-law rheology of living cells using multi-frequency force modulation atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryosuke; Okajima, Takaharu, E-mail: okajima@ist.hokudai.ac.jp [Graduate School of Information Science and Technology, Hokkaido University, Kita-ku N14 W9, Sapporo 060-0814 (Japan)

    2015-10-26

    We present multi-frequency force modulation atomic force microscopy (AFM) for mapping the complex shear modulus G* of living cells as a function of frequency over the range of 50–500 Hz in the same measurement time as the single-frequency force modulation measurement. The AFM technique enables us to reconstruct image maps of rheological parameters, which exhibit a frequency-dependent power-law behavior with respect to G{sup *}. These quantitative rheological measurements reveal a large spatial variation in G* in this frequency range for single cells. Moreover, we find that the reconstructed images of the power-law rheological parameters are much different from those obtained in force-curve or single-frequency force modulation measurements. This indicates that the former provide information about intracellular mechanical structures of the cells that are usually not resolved with the conventional force measurement methods.

  10. Mapping power-law rheology of living cells using multi-frequency force modulation atomic force microscopy

    International Nuclear Information System (INIS)

    We present multi-frequency force modulation atomic force microscopy (AFM) for mapping the complex shear modulus G* of living cells as a function of frequency over the range of 50–500 Hz in the same measurement time as the single-frequency force modulation measurement. The AFM technique enables us to reconstruct image maps of rheological parameters, which exhibit a frequency-dependent power-law behavior with respect to G*. These quantitative rheological measurements reveal a large spatial variation in G* in this frequency range for single cells. Moreover, we find that the reconstructed images of the power-law rheological parameters are much different from those obtained in force-curve or single-frequency force modulation measurements. This indicates that the former provide information about intracellular mechanical structures of the cells that are usually not resolved with the conventional force measurement methods

  11. n-3 PUFAs enhance the frequency of murine B-cell subsets and restore the impairment of antibody production to a T-independent antigen in obesity.

    Science.gov (United States)

    Teague, Heather; Fhaner, Cassie J; Harris, Mitchel; Duriancik, David M; Reid, Gavin E; Shaikh, Saame Raza

    2013-11-01

    The role of n-3 polyunsaturated fatty acids (PUFA) on in vivo B-cell immunity is unknown. We first investigated how n-3 PUFAs impacted in vivo B-cell phenotypes and antibody production in the absence and presence of antigen compared with a control diet. Lean mice consuming n-3 PUFAs for 4 weeks displayed increased percentage and frequency of splenic transitional 1 B cells. Upon stimulation with trinitrophenylated-lipopolysaccharide, n-3 PUFAs increased the number of splenic transitional 1/2, follicular, premarginal, and marginal zone B cells. n-3 PUFAs also increased surface, but not circulating, IgM. We next tested the effects of n-3 PUFAs in a model of obesity that is associated with suppressed humoral immunity. An obesogenic diet after ten weeks of feeding, relative to a lean control, had no effect on the frequency of B cells but lowered circulating IgM upon antigen stimulation. Administration of n-3 PUFAs to lean and obese mice increased the percentage and/or frequency of transitional 1 and marginal zone B cells. Furthermore, n-3 PUFAs in lean and obese mice increased circulating IgM relative to controls. Altogether, the data show n-3 PUFAs enhance B cell-mediated immunity in vivo, which has implications for immunocompromised populations, such as the obese.

  12. Is the interannual variability of summer rainfall in China dominated by precipitation frequency or intensity? An analysis of relative importance

    Science.gov (United States)

    Lu, Er; Ding, Ying; Zhou, Bing; Zou, Xukai; Chen, Xianyan; Cai, Wenyue; Zhang, Qiang; Chen, Haishan

    2016-07-01

    The summer rainfall in China has a large interannual variability, which results from the concurrent variations of precipitation frequency and intensity. Using the observed daily precipitation in the 194 stations during recent 62 years, we examine the relative importance of the frequency and intensity in the variability of the rainfall. A simple method, based on linear regression, is used to estimate the relative importance. The products of the change rates of rainfall with respect to frequency and intensity, determined from the regression, and the corresponding standard deviations of the two variables, which reflect their variation scales, are defined to measure the importance of frequency and intensity. To determine the frequency, rainfall amount, and intensity from daily precipitation, we need a threshold to define the "rainy day". In this study, we use a series of thresholds, ranging from 1 to 30 mm/day. So, while presenting the result of relative importance for each threshold, we also examine how the relative importance varies with the threshold. Results show that for the threshold of 1 mm/day, with which the rainfall may include even the light rains, the variabilities of summer rainfall in most stations are dominated by intensity. With the increase in threshold, the importance of frequency increases, while the importance of intensity decreases. When the threshold reaches 30 mm/day, with which the rainfall includes only moderate-to-heavy rains, the variabilities of the rainfall in all stations are dominated by frequency. Analysis suggests that such a change, in the dominance with the threshold, is reasonable. This reasonability, in turn, supports the reliability and robustness of the method.

  13. Audible thunder characteristic and the relation between peak frequency and lightning parameters

    Indian Academy of Sciences (India)

    OuYang Yuhua; Yuan Ping

    2012-02-01

    In recent summers, some natural lightning optical spectra and audible thunder signals were observed. Twelve events on 15 August 2008 are selected as samples since some synchronizing information about them are obtained, such as lightning optical spectra, surface E-field changes, etc. By using digital filter and Fourier transform, thunder frequency spectra in observation location have been calculated. Then the two main propagation effects, finite amplitude propagation and attenuation by air, are calculated. Upon that we take the test thunder frequency spectra and work backward to recalculate the original frequency spectra near generation location. Thunder frequency spectra and the frequency distribution varying with distance are researched. According to the theories on plasma, the channel temperature and electron density are further calculated by transition parameters of lines in lightning optical spectra. Pressure and the average ionization degree of each discharge channel are obtained by using Saha equations, charge conservation equations and particle conservation equations. Moreover, the relationship between the peak frequency of each thunder and channel parameters of the lightning is studied.

  14. Two-way optical frequency comparisons at 5 ×10-21 relative stability over 100-km telecommunication network fibers

    Science.gov (United States)

    Bercy, Anthony; Stefani, Fabio; Lopez, Olivier; Chardonnet, Christian; Pottie, Paul-Eric; Amy-Klein, Anne

    2014-12-01

    By using two-way frequency transfer, we implement a real-time frequency comparison over a uni-directional telecommunication network of 100 km using a pair of parallel fibers with simultaneous digital data transfer. The relative frequency stability is 10-15 at 1-s integration time and reaches 2 ×10-17 at 40 000 s, three orders of magnitude below the one-way fiber instability. We also demonstrate ultrahigh-resolution comparison of optical frequencies with a bidirectional scheme using a single fiber. We show that the relative stability at 1-s integration time is 7 ×10-18 and scales down to 5 ×10-21 . The same level of performance is reached when an optical link is implemented with an active compensation of the fiber noise. The fractional uncertainty of the frequency comparisons was evaluated for the best case to 2 ×10-20 . These results open the way to accurate and high-resolution frequency comparison of optical clocks over intercontinental fiber networks.

  15. Induction of chondrogenic differentiation of human adipose-derived stem cells by low frequency electric field

    Science.gov (United States)

    Mardani, Mohammad; Roshankhah, Shiva; Hashemibeni, Batool; Salahshoor, Mohammadreza; Naghsh, Erfan; Esfandiari, Ebrahim

    2016-01-01

    Background: Since when the cartilage damage (e.g., with the osteoarthritis) it could not be repaired in the body, hence for its reconstruction needs cell therapy. For this purpose, adipose-derived stem cells (ADSCs) is one of the best cell sources because by the tissue engineering techniques it can be differentiated into chondrocytes. Chemical and physical inducers is required order to stem cells to chondrocytes differentiating. We have decided to define the role of electric field (EF) in inducing chondrogenesis process. Materials and Methods: A low frequency EF applied the ADSCs as a physical inducer for chondrogenesis in a 3D micromass culture system which ADSCs were extracted from subcutaneous abdominal adipose tissue. Also enzyme-linked immunosorbent assay, methyl thiazolyl tetrazolium, real time polymerase chain reaction and flowcytometry techniques were used for this study. Results: We found that the 20 minutes application of 1 kHz, 20 mv/cm EF leads to chondrogenesis in ADSCs. Although our results suggest that application of physical (EF) and chemical (transforming growth factor-β3) inducers at the same time, have best results in expression of collagen type II and SOX9 genes. It is also seen EF makes significant decreased expression of collagens type I and X genes. Conclusion: The low frequency EF can be a good motivator to promote chondrogenic differentiation of human ADSCs. PMID:27308269

  16. Event-related desynchronization and synchronization in MEG: Framework for analysis and illustrative datasets related to discrimination of frequency-modulated tones.

    Science.gov (United States)

    Zygierewicz, J; Sieluzycki, C; König, R; Durka, P J

    2008-02-15

    We introduce a complete framework for the calculation of statistically significant event-related desynchronization and synchronization (ERD/ERS) in the time-frequency plane for magnetoencephalographic (MEG) data, and provide free Internet access to software and illustrative datasets related to a classification task of frequency-modulated (FM) tones. Event-related changes in MEG were analysed on the basis of the normal component of the magnetic field acquired by the 148 magnetometers of the hardware configuration of our whole-head MEG device, and by computing planar gradients in longitudinal and latitudinal direction. Time-frequency energy density for the magnetometer as well as the two gradient configurations is first approximated using short-time Fourier transform. Subsequently, detailed information is obtained from high-resolution time-frequency maps for the most interesting sensors by means of the computationally much more demanding matching pursuit parametrization. We argue that the ERD/ERS maps are easier to interpret in the gradient approaches and discuss the superior resolution of the matching pursuit time-frequency representation compared to short-time Fourier and wavelet transforms. Experimental results are accompanied by the following resources, available from http://brain.fuw.edu.pl/MEG: (a) 48 high-resolution figures presenting the results of four subjects in all applicable settings, (b) raw datasets, and (c) complete software environment, allowing to recompute these figures from the raw datasets. PMID:17983663

  17. Relation between deep bioluminescence and oceanographic variables: A statistical analysis using time-frequency decompositions

    Science.gov (United States)

    Martini, S.; Nerini, D.; Tamburini, C.

    2014-09-01

    We consider the statistical analysis of a 1.7-year high-frequency sampled time series, between 2009 and 2010, recorded at the ANTARES observatory in the deep NW Mediterranean Sea (2475 m depth). The objective was to estimate relationships between bioluminescence and environmental time series (temperature, salinity and current speed). As this entire dataset is characterized by non-linearity and non-stationarity, two time-frequency decomposition methods (wavelet and Hilbert-Huang) were used. These mathematical methods are dedicated to the analysis of a signal at various time and frequencies scales. This work propose some statistical tools dedicated to the study of relationships between two time series. Our study highlights three events of high bioluminescence activity in March 2009, December 2009 and March 2010. We demonstrate that the two events occurring in March 2009 and 2010 are correlated to the arrival of newly formed deep water masses at frequencies of approximately 4.8×10-7 (period of 24.1 days). In contrast, the event in December 2009 is only correlated with current speed at frequencies of approximately 1.9×10-6 (period of 6.0 days). The use of both wavelet and Hilbert-Huang transformations has proven to be successful for the analysis of multivariate time series. These methods are well-suited in a context of the increasing number of long time series recorded in oceanography.

  18. Erythrocytes modulate cell cycle progression but not the baseline frequency of sister chromatid exchanges in pig lymphocytes

    OpenAIRE

    Miguel A. Reigosa; Sonia Soloneski; Garcia, Carlos F.; Larramendy, Marcelo L.

    1997-01-01

    The effect of co-culturing varying concentrations of pig and human red blood cells (RBCs) on the baseline frequency of sister chromatid exchanges (SCEs) and cell-cycle progression in pig plasma (PLCs) and whole blood leukocyte cultures (WBCs) was studied. No variation in SCE frequency was observed between pig control WBC and PLC. Addition of pig and human RBCs to pig PLCs did not modify the baseline frequency of SCEs. On the other hand, cell proliferation was slower in PLCs than in WBCs. The ...

  19. Relation between QT dispersion, left ventricle systolic function and frequency of ventricular arrhythmias in coronary patients

    Directory of Open Access Journals (Sweden)

    Stoičkov Viktor

    2007-01-01

    Full Text Available Introduction QT dispersion (QTd is a measure of non-homogeneous repolarisation of the myocardium and is used as an indicator of arrhythmogenicity. Objective The aim of this study was to assess the relation between QT dispersion, left ventricle systolic function and frequency of ventricular arrhythmias in coronary patients. Method We studied 290 coronary patients, 72 with angina pectoris and 218 after myocardial infarction. Eighty-one coronary patients had frequent and complex ventricular arrhythmias (out of them 19 had ventricular tachycardia and 209 were without arrhythmias or with infrequent ventricular premature contractions (VPC≤10/h. In all patients, QT dispersion, exercise test, 24-hour Holter monitoring and echocardiographic examination were performed. Results Patients with frequent and complex ventricular arrhythmias had significantly higher values of QTd (71.8±25.5 vs 55.6±21.7 ms; p<0.001, corrected QT dispersion (QTdc: 81.3±31.5 vs. 60.3±26.1 ms; p<0.001, left ventricular end-diastolic diameter (LVEDd: 56.2±6.9 vs. 53.4±6.2 mm; p<0.001 and left ventricular end-systolic diameter (LVESd: 39.5±6.2 vs. 36.0±6.3 mm; p<0.001, and significantly lower values of left ventricular ejection fraction (LVEF: 47.7±13.9 vs. 55.9±11.6%; p<0.001 in comparison to those without arrhythmias or with infrequent VPC. Patients with VT had significantly higher values of QTd and QTdc in comparison to other patients with frequent and complex ventricular arrhythmias (83.8±17.1 vs. 69.4±26.2 ms; p<0.02 for QTd; 101.1±23.9:77.6±31.4 ms; p<0.005 for QTdc. There is a significant negative correlation of QTd and QTdc with LVEF, and a significant positive correlation of QTd and QTdc with inside dimensions of the left ventricle, in patients with frequent and complex ventricular arrhythmias. Conclusion The study demonstrated that patients with frequent and complex ventricular arrhythmias had significantly higher values of QTd and QTdc, as well as a higher

  20. Relative Frequency of Nosocomial Microorganisms at Unicamp University Hospital from 1987 to 1994

    Directory of Open Access Journals (Sweden)

    TRESOLDI Antonia Teresinha

    1997-01-01

    Full Text Available The frequency of microorganisms identified in nosocomial infections at Unicamp University Hospital from 1987 to 1994 was analysed. The most common microorganism was S. aureus (20.9%, which was found in surgical wound, bloodstream and arterial-venous infections. In urinary tract infections (UTI, gram-negative rods (56.5% and yeasts (9% predominated. A. baumannii isolates were observed to have increased in the last three years. There was a gradual increase in the frequency of coagulase-negative staphylococci and A. baumannii in bloodstream infections but there wasn?t any change in Candida sp

  1. On-line Measurements and Control of Viable Cell Density in Cell Culture Manufacturing Processes using Radio-frequency Impedance.

    Science.gov (United States)

    Carvell, John P; Dowd, Jason E

    2006-03-01

    In this work, radio-frequency (RF) impedance is reviewed as a method for monitoring and controlling cell culture manufacturing processes. It is clear from the many publications cited that RF Impedance is regarded as an accurate and reliable method for measuring the live cell bio-volume both on-line and off-line and the technology is also sutable for animal cells in suspension, attached to micro-carriers or immobilized in fixed beds. In cGMP production, RF Impedance is being used in three main areas. Firstly, it is being used as a control instrument for maintaining consistent perfusion culture allowing the bioreactor to operate under optimum conditions for maximum production of recombinant proteins. In the second application it has not replaced traditional off-line live cell counting techniques but it is being used as an additional monitoring tool to check product conformance. Finally, RF Impedance is being used to monitor the concentration of live cells immobilized on micro-carriers or packed beds in cGMP processes where traditional off-line live cell counting methods are inaccurate or impossible to perform. PMID:19003069

  2. Dementia-Related Work Activities of Home Care Nurses and Aides: Frequency, Perceived Competence, and Continuing Education Priorities

    Science.gov (United States)

    Morgan, Debra G.; Kosteniuk, Julie G.; O'Connell, Megan E.; Dal Bello-Haas, Vanina; Stewart, Norma J.; Karunanayake, Chandima

    2016-01-01

    An understanding of the specific dementia learning needs of home care staff is needed to plan relevant continuing education (CE) programs and supports. The study's objective was to examine frequency and perceived competence in performing 20 dementia-related work activities, and identify CE priorities among home care staff. A cross-sectional survey…

  3. Effects of weak nonlinearity on the dispersion relation and frequency band-gaps of a periodic Bernoulli–Euler beam

    DEFF Research Database (Denmark)

    Sorokin, Vladislav S.; Thomsen, Jon Juel

    2016-01-01

    The paper deals with analytically predicting the effects of weak nonlinearity on the dispersion relation and frequency band-gaps of a periodic Bernoulli– Euler beam performing bending oscillations. Two cases are considered: (i) large transverse deflections, where nonlinear (true) curvature...

  4. Alcohol drinking frequency in relation to subsequent changes in waist circumference

    DEFF Research Database (Denmark)

    Tolstrup, Janne S; Halkjaer, Jytte; Heitmann, Berit L;

    2008-01-01

    BACKGROUND: Cross-sectional studies have reported a lower prevalence of abdominal obese persons among frequent drinkers than among nonfrequent drinkers. OBJECTIVE: We tested the hypothesis that drinking frequency is associated with subsequent changes in waist circumference. DESIGN: Data come from...

  5. Radio frequency heating of foods: principles, applications and related properties--a review.

    Science.gov (United States)

    Piyasena, Punidadas; Dussault, Chantal; Koutchma, Tatiana; Ramaswamy, H S; Awuah, G B

    2003-01-01

    Radio frequency (RF) heating is a promising technology for food applications because of the associated rapid and uniform heat distribution, large penetration depth and lower energy consumption. Radio frequency heating has been successfully applied for drying, baking and thawing of frozen meat and in meat processing. However, its use in continuous pasteurization and sterilization of foods is rather limited. During RF heating, heat is generated within the product due to molecular friction resulting from oscillating molecules and ions caused by the applied alternating electric field. RF heating is influenced principally by the dielectric properties of the product when other conditions are kept constant. This review deals with the current status of RF heating applications in food processing, as well as product and system specific factors that influence the RF heating. It is evident that frequency level, temperature and properties of food, such as viscosity, water content and chemical composition affect the dielectric properties and thus the RF heating of foods. Therefore, these parameters should be taken into account when designing a radio frequency heating system for foods.

  6. Design characteristics of food frequency questionnaires in relation to their validity

    NARCIS (Netherlands)

    Molag, M.L.; Vries, J.H.M. de; Ocké, M.C.; Dagnelie, P.C.; Brandt, P.A. van den; Jansen, M.C.J.F.; Staveren, W.A. van; Veer, P. van 't

    2007-01-01

    The authors investigated the role of food frequency questionnaire (FFQ) design, including length, use of portion-size questions, and FFQ origin, in ranking subjects according to their nutrient intake. They also studied the ability of the FFQ to detect differences in energy intake between subgroups a

  7. Radio frequency heating of foods: principles, applications and related properties--a review.

    Science.gov (United States)

    Piyasena, Punidadas; Dussault, Chantal; Koutchma, Tatiana; Ramaswamy, H S; Awuah, G B

    2003-01-01

    Radio frequency (RF) heating is a promising technology for food applications because of the associated rapid and uniform heat distribution, large penetration depth and lower energy consumption. Radio frequency heating has been successfully applied for drying, baking and thawing of frozen meat and in meat processing. However, its use in continuous pasteurization and sterilization of foods is rather limited. During RF heating, heat is generated within the product due to molecular friction resulting from oscillating molecules and ions caused by the applied alternating electric field. RF heating is influenced principally by the dielectric properties of the product when other conditions are kept constant. This review deals with the current status of RF heating applications in food processing, as well as product and system specific factors that influence the RF heating. It is evident that frequency level, temperature and properties of food, such as viscosity, water content and chemical composition affect the dielectric properties and thus the RF heating of foods. Therefore, these parameters should be taken into account when designing a radio frequency heating system for foods. PMID:14669879

  8. Dairy cow defecation and urination frequency and spatial distribution in relation to time-limited grazing

    NARCIS (Netherlands)

    Oudshoorn, F.W.; Kristensen, T.; Sharak Nadimi, I.

    2008-01-01

    The objective of this paper was to investigate the effect of limited grazing time on urination and defecation frequency, spatial distribution of excrement in the paddock, and the resulting nitrogen balance at animal and field level. During a 6-week period in early summer, 60 Holstein Frisian dairy c

  9. Role of PTHrP(1-34) Pulse Frequency Versus Pulse Duration to Enhance Mesenchymal Stromal Cell Chondrogenesis.

    Science.gov (United States)

    Fischer, Jennifer; Ortel, Marlen; Hagmann, Sebastien; Hoeflich, Andreas; Richter, Wiltrud

    2016-12-01

    Generation of phenotypically stable, articular chondrocytes from mesenchymal stromal cells (MSCs) is still an unaccomplished task, with formation of abundant, hyaline extracellular matrix, and avoidance of hypertrophy being prime challenges. We recently demonstrated that parathyroid hormone-related protein (PTHrP) is a promising factor to direct chondrogenesis of MSCs towards an articular phenotype, since intermittent PTHrP application stimulated cartilage matrix production and reduced undesired hypertrophy. We here investigated the role of frequency, pulse duration, total exposure time, and underlying mechanisms in order to unlock the full potential of PTHrP actions. Human MSC subjected to in vitro chondrogenesis for six weeks were exposed to 2.5 nM PTHrP(1-34) pulses from days 7 to 42. Application frequency was increased from three times weekly (3 × 6 h/week) to daily maintaining either the duration of individual pulses (6 h/day) or total exposure time (18 h/week; 2.6 h/day). Daily PTHrP treatment significantly increased extracellular matrix deposition regardless of pulse duration and suppressed alkaline-phosphatase activity by 87%. High total exposure time significantly reduced cell proliferation at day 14. Pulse duration was critically important to significantly reduce IHH expression, but irrelevant for PTHrP-induced suppression of the hypertrophic markers MEF2C and IBSP. COL10A1, RUNX2, and MMP13 expression remained unaltered. Decreased IGFBP-2, -3, and -6 expression suggested modulated IGF-I availability in PTHrP groups, while drop of SOX9 protein levels during the PTHrP-pulse may delay chondroblast formation and hypertrophy. Overall, the significantly optimized timing of PTHrP-pulses demonstrated a vast potential to enhance chondrogenesis of MSC and suppress hypertrophy possibly via superior balancing of IGF- and SOX9-related mechanisms. J. Cell. Physiol. 231: 2673-2681, 2016. © 2016 Wiley Periodicals, Inc. PMID:27548511

  10. Frequency analysis of TRBV subfamily sjTRECs to characterize T-cell reconstitution in acute leukemia patients after allogeneic hematopoietic stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Yang Lijian

    2011-04-01

    Full Text Available Abstract Background Allogeneic hematopoietic stem cell transplantation (allo-HSCT leads to a prolonged state of immunodeficiency and requires reconstitution of normal T-cell immunity. Signal joint T-cell receptor excision DNA circles (sjTRECs are markers of developmental proximity to the thymus that have been used to evaluate thymic function related to T-cell immune reconstitution after HSCT. To assess the proliferative history in different T-cell receptor beta variable region (TRBV subfamilies of T cells after HSCT, expansion of TRBV subfamily-naive T cells was determined by analysis of a series of TRBV-BD1 sjTRECs. Methods sjTRECs levels were detected by real-time quantitative polymerase chain reaction (PCR in peripheral blood mononuclear cells (PBMCs from 43 Chinese acute leukemia patients who underwent allo-HSCT. Twenty-three TRBV-BD1 sjTRECs were amplified by semi-nested PCR. Sixteen age-matched healthy volunteers served as normal controls. Results sjTRECs levels were low or undetectable in the first 6 weeks after allo-HSCT and increased after 8 weeks post HSCT; however, sjTRECs levels at week 20 post-HSCT were still less than normal controls. Frequencies of TRBV subfamily sjTRECs in PBMCs from recipients at week 8 post-HSCT (29.17 ± 20.97% or at week 16 post-HSCT (38.33 ± 9.03% were significantly lower than those in donors (47.92 ± 13.82% or recipients at pre-HSCT (45.83 ± 14.03%. However, frequencies of TRBV subfamily sjTRECs in recipients at week 30 post-HSCT (42.71 ± 21.62% were similar to those in donors and recipients at pre-HSCT. sjTRECs levels in donors had a positive linear correlation with sjTRECs levels in recipients within 8-12 weeks post-HSCT. Patients with acute graft-versus-host disease (GVHD or chronic GVHD had profoundly reduced TRECs levels during the first year post-HSCT. Frequencies of BV22-BD1 sjTRECs and BV23-BD1 sjTRECs in patients with GVHD were significantly lower than those in recipients at pre-HSCT, and the

  11. Temperature dependency of cupular mechanics and hair cell frequency selectivity in the fish canal lateral line organ

    NARCIS (Netherlands)

    Wiersinga-Post, JEC; van Netten, SM

    2000-01-01

    The mechanical frequency selectivity of the cupula located in the supraorbital lateral line canal and the frequency selectivity of the hair cells driven by the cupula were measured simultaneously in vivo. Laser interferometry was used to measure cupular mechanics and extracellular receptor potential

  12. 50Hz Extremely Low Frequency Electromagnetic Fields Enhance Protein Carbonyl Groups Content in Cancer Cells: Effects on Proteasomal Systems

    Directory of Open Access Journals (Sweden)

    A. M. Eleuteri

    2009-01-01

    Full Text Available Electromagnetic fields are an assessed cause of prolonging free radicals lifespan. This study was carried out to investigate the influence of extremely low frequency electromagnetic fields on protein oxidation and on the 20S proteasome functionality, the complex responsible for the degradation of oxidized proteins. Caco 2 cells were exposed, for 24–72 hours, to 1 mT, 50 Hz electromagnetic fields. The treatment induced a time-dependent increase both in cell growth and in protein oxidation, more evident in the presence of TPA, while no changes in cell viability were detected. Exposing the cells to 50 Hz electromagnetic fields caused a global activation of the 20S proteasome catalytic components, particularly evident at 72 hours exposure and in the presence of TPA. The finding that EGCG, a natural antioxidant compound, counteracted the field-related pro-oxidant effects demonstrates that the increased proteasome activity was due to an enhancement in intracellular free radicals.

  13. Dispersive radio frequency electrometry using Rydberg atoms in a prism-shaped atomic vapor cell

    Science.gov (United States)

    Fan, H. Q.; Kumar, S.; Kübler, H.; Shaffer, J. P.

    2016-05-01

    We introduce a method to measure radio frequency (RF) electric fields (E-fields) using atoms contained in a prism-shaped vapor cell. The method utilizes the concept of electromagnetically induced transparency with Rydberg atoms. The RF E-field induces changes in the index of refraction of the vapor resulting in deflection of the probe laser beam as it passes through the prism-shaped vapor cell. We measured a minimum RF E-field of 8.25 μ {{Vcm}}-1 with a sensitivity of ∼ 46.5 μ {{Vcm}}-1 {{Hz}}-1/2. The experimental results agree with a numerical model that includes dephasing effects. We discuss possible improvements to obtain higher sensitivity for RF E-field measurements.

  14. Retrospective biodosimetry using translocation frequency in a stable cell of occupationally exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Two cases of hematological malignancies were reported in an industrial radiography company over a year, which were reasonably suspected of being consequences of prolonged exposure to ionizing radiation because of the higher incidence than expected in the general population. We analyzed chromosomal aberrations in the peripheral blood lymphocytes from the other workers who had been working under similar circumstances as the patients in the company. Among the subjects tested, 10 workers who belonged to the highest band were followed up periodically for 1.5 years since the first analysis. The aim of this study was to clarify pertinence of translocation analysis to an industrial set-up where chronic exposure was commonly expected. To be a useful tool for a retrospective biodosimetry, the aberrations need to be persistent for a decade or longer. Therefore we calculated the decline rates and half-lives of frequency for both a reciprocal translocation and a dicentric chromosome and compared them. In this study, while the frequency of reciprocal translocations was maintained at the initial level, dicentric chromosomes were decreased to 46.9% (31.0–76.5) of the initial frequency over the follow-up period. Our results support the long-term stability of reciprocal translocation through the cell cycle and validate the usefulness of translocation analysis as a retrospective biodosimetry for cases of occupational exposure. (author)

  15. Regulatory T cell frequencies are increased in preterm infants with clinical early-onset sepsis.

    Science.gov (United States)

    Pagel, J; Hartz, A; Figge, J; Gille, C; Eschweiler, S; Petersen, K; Schreiter, L; Hammer, J; Karsten, C M; Friedrich, D; Herting, E; Göpel, W; Rupp, J; Härtel, C

    2016-08-01

    The predisposition of preterm neonates to invasive infection is, as yet, incompletely understood. Regulatory T cells (Tregs ) are potential candidates for the ontogenetic control of immune activation and tissue damage in preterm infants. It was the aim of our study to characterize lymphocyte subsets and in particular CD4(+) CD25(+) forkhead box protein 3 (FoxP3)(+) Tregs in peripheral blood of well-phenotyped preterm infants (n = 117; 23 + 0 - 36 + 6 weeks of gestational age) in the first 3 days of life in comparison to term infants and adults. We demonstrated a negative correlation of Treg frequencies and gestational age. Tregs were increased in blood samples of preterm infants compared to term infants and adults. Notably, we found an increased Treg frequency in preterm infants with clinical early-onset sepsis while cause of preterm delivery, e.g. chorioamnionitis, did not affect Treg frequencies. Our data suggest that Tregs apparently play an important role in maintaining maternal-fetal tolerance, which turns into an increased sepsis risk after preterm delivery. Functional analyses are needed in order to elucidate whether Tregs have potential as future target for diagnostics and therapeutics.

  16. Regulatory T cell frequencies are increased in preterm infants with clinical early-onset sepsis.

    Science.gov (United States)

    Pagel, J; Hartz, A; Figge, J; Gille, C; Eschweiler, S; Petersen, K; Schreiter, L; Hammer, J; Karsten, C M; Friedrich, D; Herting, E; Göpel, W; Rupp, J; Härtel, C

    2016-08-01

    The predisposition of preterm neonates to invasive infection is, as yet, incompletely understood. Regulatory T cells (Tregs ) are potential candidates for the ontogenetic control of immune activation and tissue damage in preterm infants. It was the aim of our study to characterize lymphocyte subsets and in particular CD4(+) CD25(+) forkhead box protein 3 (FoxP3)(+) Tregs in peripheral blood of well-phenotyped preterm infants (n = 117; 23 + 0 - 36 + 6 weeks of gestational age) in the first 3 days of life in comparison to term infants and adults. We demonstrated a negative correlation of Treg frequencies and gestational age. Tregs were increased in blood samples of preterm infants compared to term infants and adults. Notably, we found an increased Treg frequency in preterm infants with clinical early-onset sepsis while cause of preterm delivery, e.g. chorioamnionitis, did not affect Treg frequencies. Our data suggest that Tregs apparently play an important role in maintaining maternal-fetal tolerance, which turns into an increased sepsis risk after preterm delivery. Functional analyses are needed in order to elucidate whether Tregs have potential as future target for diagnostics and therapeutics. PMID:27163159

  17. The heat capacity of lipid membranes in finite reservoirs and the relation to the frequency dependence

    CERN Document Server

    Mosgaard, Lars D; Heimburg, Thomas

    2013-01-01

    Membranes are two-dimensional structures embedded in a three-dimensional heat reservoir. At constant temperature, the heat capacity is proportional to the enthalpy fluctuations. However, when the membrane is embedded in a finite aqueous reservoir, the enthalpy and temperature fluctuations of the reservoir are intimately coupled to the enthalpy fluctuations of the membrane. Employing Monte Carlo simulations, we show that membranes embedded in water reservoirs of various sizes display different enthalpy fluctuations and fluctuation time scales. In particular, larger water reservoirs result in a larger enthalpy fluctuations of the membrane and in slower fluctuation time scales (relaxation times). In periodic processes such as sound propagation in membranes, the membrane has only a finite time available to exchange heat with the medium. A larger frequency therefore reduces the accessible volume of the reservoir. We discuss the relevance of these considerations for the frequency dependence of the compressibility a...

  18. Reproductive integrity of mammalian cells exposed to power frequency electromagnetic fields.

    Science.gov (United States)

    Livingston, G K; Witt, K L; Gandhi, O P; Chatterjee, I; Roti Roti, J L

    1991-01-01

    Human lymphocytes and Chinese hamster ovary (CHO) fibroblasts were analyzed for cytogenetic and cytotoxic endpoints to determine whether exposure to power frequency (60 Hz) electromagnetic fields (EMF) interferes with normal cell growth and reproduction. An exposure chamber was built to apply variable electric current densities of 3, 30, 300, and 3,000 microA/cm2, simultaneously with a fixed magnetic field of 2.2 G to proliferating cells. The current densities were chosen to bracket those that may be induced in the human body by fields measured beneath high voltage (765 kV) power transmission lines. The electric current was applied through the media of a cell culture chamber positioned between two stainless steel electrodes but separated from direct contact with the culture media by a salt bridge composed of a 1% agarose gel. The magnetic field was generated using two pairs of Helmholtz coils driven 73 degrees out of phase producing an elliptically polarized magnetic field 36 degrees out of phase with the electric field. The EMFs were measured and mapped inside the cell culture chamber to insure their uniformity. CHO cells were exposed continuously for 24-96 hr (depending on experiment) and human lymphocytes were exposed continuously for 72 hr. The EMFs were monitored throughout the entire treatment period using a multichannel chart recorder to verify continuous application of the desired fields. Sister-chromatid exchange and micronuclei were monitored to evaluate the potential for genotoxicity. In addition, standard growth curves, clonogenicity, and cell cycle kinetics were analyzed to evaluate possible cytotoxic effects. The experimental data consistently showed that the growth rate and reproductive integrity of both cell types was unaffected by exposure to the electromagnetic fields. PMID:1991460

  19. Examining Online Shopping Services in Relation to Experience and Frequency of Using Internet Retailing

    OpenAIRE

    Alin OPREANA

    2013-01-01

    E-shopping has the potential to replace traditional in-store shopping. It is well perceived that information and communication technologies have great impacts on modern society - they are changing how and where we work, shop, and in general terms how we live our lives. In this study, we use a survey instrument to examine the association between experience level with Internet and e-shopping and consumers’ frequency of online purchasing, while considering sex as a passive influencer. We study t...

  20. Cortical Auditory Event Related Potentials (P300) for Frequency Changing Dynamic Tones

    Science.gov (United States)

    Kalaiah, Mohan Kumar

    2016-01-01

    Background and Objectives P300 has been studied with a variety of stimuli. However, the nature of P300 has not been investigated for deviant stimuli which change its characteristics from standard stimuli after a period of time from onset. Subjects and Methods Nine young adults with normal hearing participated in the study. The P300 was elicited using an oddball paradigm, the probability of standard and deviant stimuli was 80% and 20% respectively. Six stimuli were used to elicit P300, it included two pure-tones (1,000 Hz and 2,000 Hz) and four tone-complexes (tones with frequency changes). Among these stimuli, 1,000 Hz tone served as standard while others served as deviant stimuli. The P300 was recorded in five separate blocks, with one of the deviant stimuli as target in each block. Electroencephalographic was recorded from electrode sites Fz, Cz, C3, C4, and Pz. Latency and amplitude of components of the cortical auditory evoked potentials were measured at Cz. Results Waveforms obtained in the present study shows that, all the deviant stimuli elicited obligatory P1-N1-P2 for stimulus onset. 2,000 Hz deviant tone elicited P300 at a latency of 300 ms. While, tone-complexes elicited acoustic change complex (ACC) for frequency changes and finally elicited P300 at a latency of 600 ms. In addition, the results showed shorter latency and larger amplitude ACC and P300 for rising tone-complexes compared to falling tone-complexes. Conclusions Tone-complexes elicited distinct waveforms compared to 2,000 Hz deviant tone. Rising tone-complexes which had an increase in frequency elicited shorter latency and larger amplitude responses, which could be attributed to perceptual bias for frequency changes. PMID:27144230

  1. The Relative Frequency, Clinical and Laboratory Findings of Adult Glomerulonephritidies in Tehran

    OpenAIRE

    Afsoon Emami Naini; A Amini Harandi; S Ossareh; A. Ghods; Bastani, B; Taheri, S

    2006-01-01

    Background: Renal diseases information is population-based and has great geographic variability. Due to the lack of national renal data registry system, there is no information on the prevalence rate, and clinical and laboratory features of various glomerulonephritidies (GNs) in Iran. Methods: In a retrospective cross sectional study, we analyzed 462 adult renal biopsies in Hashemi Nejad hospital, Tehran, Iran. We determined the prevalence rate and the frequency of different clinical and...

  2. Increasingly complex bimanual multi-frequency coordination patterns are equally easy to perform with on-line relative velocity feedback.

    Science.gov (United States)

    Boyles, Jason; Panzer, Stefan; Shea, Charles H

    2012-02-01

    An experiment was conducted to determine whether multi-frequency continuous bimanual circling movements of varying difficulty (1:2, 2:3, 3:4, and 4:5) could be effectively performed following relatively little practice when on-line continuous relative velocity feedback is provided. The between-subjects results indicate extremely effective bimanual multi-frequency performance for all coordination patterns with relatively stable and continuous movements of both limbs. The findings suggest that the previous performance effects using Lissajous feedback with reciprocal movement can be extended to circling movements using on-line relative velocity feedback. Contrary to the long-held position that these coordination patterns result in increasing difficulty, we failed to find systematic relative velocity error, variability, or bias differences between the participants performing the various multi-frequency coordination patterns. Indeed, coordination error, variability, and biases were remarkably low for each of the tasks. The results clearly indicate the ease with which participants are able to produce bimanual coordination patterns typically considered difficult if not impossible when salient visual information is provided that allows the participants to detect and correct their coordination errors.

  3. Age-related changes in frequency of mind-wandering and task-related interferences during memory encoding and their impact on retrieval.

    Science.gov (United States)

    Maillet, David; Rajah, M Natasha

    2013-01-01

    During the performance of cognitive tasks such as memory encoding, attention can become decoupled from the external environment and instead focused on internal thoughts related to the appraisal of the current task (task-related interferences; TRI), or personal thoughts unrelated to the task at hand (mind-wandering; MW). However, the association between the frequency of these thoughts experienced at encoding and retrieval accuracy in young and older adults remains poorly understood. In this study young and older adults encoded lists of words using one of two encoding tasks: judging whether words are man-made/natural (objective task), or whether they are pleasant/neutral (subjective task). We measured the frequency of TRI and MW at encoding, and related them to retrieval accuracy in both age groups. We found that encoding task influenced the type of internal thoughts experienced by young, but not older, adults: young exhibited greater MW in the subjective vs the objective task, and greater TRI in the objective vs subjective encoding task. Second, across both tasks we found marked age-related decreases in both MW and TRI at encoding, and frequency of these thoughts negatively impacted memory retrieval in young adults only. We discuss these findings in relation to current theories of ageing, attention and memory.

  4. Age-related Deterioration of Hematopoietic Stem Cells

    OpenAIRE

    Kim, Mi Jung; Kim, Min Hwan; Kim, Seung Ah; Chang, Jae Suk

    2008-01-01

    Aging is the process of system deterioration over time in the whole body. Stem cells are self-renewing and therefore have been considered exempt from the aging process. Earlier studies by Hayflick showed that there is an intrinsic limit to the number of divisions that mammalian somatic cells can undergo, and cycling kinetics and ontogeny-related studies strongly suggest that even the most primitive stem cell functions exhibit a certain degree of aging. Despite these findings, studies on the e...

  5. Controlled meal frequency without caloric restriction alters peripheral blood mononuclear cell cytokine production

    Directory of Open Access Journals (Sweden)

    Longo Dan L

    2011-03-01

    Full Text Available Abstract Background Intermittent fasting (IF improves healthy lifespan in animals by a mechanism involving reduced oxidative damage and increased resistance to stress. However, no studies have evaluated the impact of controlled meal frequency on immune responses in human subjects. Objective A study was conducted to establish the effects of controlled diets with different meal frequencies, but similar daily energy intakes, on cytokine production in healthy male and female subjects. Design In a crossover study design with an intervening washout period, healthy normal weight middle-age male and female subjects (n = 15 were maintained for 2 months on controlled on-site one meal per day (OMD or three meals per day (TMD isocaloric diets. Serum samples and peripheral blood mononuclear cells (PBMCs culture supernatants from subjects were analyzed for the presence of inflammatory markers using a multiplex assay. Results There were no significant differences in the inflammatory markers in the serum of subjects on the OMD or TMD diets. There was an increase in the capacity of PBMCs to produce cytokines in subjects during the first month on the OMD or TMD diets. Lower levels of TNF-α, IL-17, MCP-1 and MIP-1β were produced by PBMCs from subjects on the OMD versus TMD diet. Conclusions PBMCs of subjects on controlled diets exhibit hypersensitivities to cellular stimulation suggesting that stress associated with altered eating behavior might affect cytokine production by immune cells upon stimulation. Moreover, stimulated PBMCs derived from healthy individuals on a reduced meal frequency diet respond with a reduced capability to produce cytokines.

  6. Correlation between frequencies of blood monocytic myeloid-derived suppressor cells, regulatory T cells and negative prognostic markers in patients with castration-resistant metastatic prostate cancer

    DEFF Research Database (Denmark)

    Idorn, Manja; Køllgaard, Tania; Kongsted, Per;

    2014-01-01

    function of immune suppressive cell subsets in the peripheral blood of 41 patients with prostate cancer (PC) and 36 healthy donors (HD) showed a significant increase in circulating CD14(+) HLA-DR(low/neg) monocytic MDSC (M-MDSC) and Tregs in patients with PC compared to HD. Furthermore, M-MDSC frequencies......Myeloid-derived suppressor cells (MDSC) are believed to play a role in immune suppression and subsequent failure of T cells to mount an efficient anti-tumor response, by employing both direct T-cell inhibition as well as induction of regulatory T cells (Tregs). Investigating the frequency and...... correlated positively with Treg levels. In vitro proliferation assay with autologous T cells confirmed M-MDSC-mediated T-cell suppression, and intracellular staining of immune suppressive enzyme iNOS revealed a higher expression in M-MDSC from patients with PC. Increased frequencies of M-MDSC correlated with...

  7. Cell Phones: A Bibliometric Analysis Related to Business Students

    Science.gov (United States)

    Piotrowski, Chris

    2014-01-01

    Recent reviews of the literature indicate that the scope of research on cell or mobile phones covers a vast typology (Piotrowski & Kass, 2013). The majority of this research is concentrated in the technology, education, and social sciences fields. However, there is a dearth of bibliometric studies on cell phones related to business. To that…

  8. A stabilized 18 GHz chip-scale optical frequency comb at 2.8x10-16 relative inaccuracy

    CERN Document Server

    Huang, S -W; Yu, M; McGuyer, B H; Kwong, D -L; Zelevinsky, T; Wong, C W

    2015-01-01

    Optical frequency combs, coherent light sources that connect optical frequencies with microwave oscillations, have become the enabling tool for precision spectroscopy, optical clockwork and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but four-wave-mixing in high-Q resonators have emerged as alternative platforms. Here we report the generation and full stabilization of CMOS-compatible optical frequency combs. The spiral microcomb's two degrees-of-freedom, one of the comb line and the native 18 GHz comb spacing, are first simultaneously phase-locked to known optical and microwave references. Second, with pump power control, active comb spacing stabilization improves the long-term stability by six orders-of-magnitude, reaching an instrument-limited 3.6 mHz/sqrt(t) residual instability. Third, referencing thirty-three of the nitride frequency comb lines against a fiber comb, we demonstrate the comb tooth-to-tooth frequency relative inaccu...

  9. Extra-Low-Frequency Magnetic Fields alter Cancer Cells through Metabolic Restriction

    CERN Document Server

    Li, Ying

    2012-01-01

    Background: Biological effects of extra-low-frequency (ELF) magnetic fields (MF) have lacked a credible mechanism of interaction between MFs and living material. Objectives: Examine the effect of ELF-MFs on cancer cells. Methods: Five cancer cell lines were exposed to ELF-MFs within the range of 0.025 to 5 microT, and the cells were examined for karyotype changes after 6 days. Results: All cancer cells lines lost chromosomes from MF exposure, with a mostly flat dose-response. Constant MF exposures for three weeks allow a rising return to the baseline, unperturbed karyotypes. From this point, small MF increases or decreases are again capable of inducing karyotype contractions. Our data suggests that the karyotype contractions are caused by MF interference with mitochondria's ATP synthase (ATPS), compensated by the action of AMP-activated Protein Kinase (AMPK). The effects of MFs are similar to those of the ATPS inhibitor oligomycin. They are amplified by metformin, an AMPK stimulator, and attenuated by resisti...

  10. Stem cells: Potential therapy for age-related diseases

    DEFF Research Database (Denmark)

    Kassem, Moustapha

    2006-01-01

    -engineered organs) to restore the functions of damaged or defective tissues and organs and thus to "rejuvenate" the failing aging body. One of the most important sources for cellular medicine is embryonic and adult (somatic) stem cells (SSCs). One example of SCCs with enormous clinical potential is the mesenchymal......Aging is associated with a progressive failing of tissues and organs of the human body leading to a large number of age-related diseases. Regenerative medicine is an emerging clinical discipline that aims to employ cellular medicines (normal cells, ex vivo expanded cells, or tissue...... stem cells (MSCs) that are present in the bone marrow and are able to differentiate into cell types such as osteoblasts, chondrocytes, endothelial cells, and probably also neuron-like cells. Because of the ease of their isolation and their extensive differentiation potential, MSCs are among the first...

  11. Frequency of Relation Type as a Determinant of Conceptual Combination: A Reanalysis

    Science.gov (United States)

    Wisniewski, Edward J.; Murphy, Gregory L.

    2005-01-01

    C. L. Gagn? and E. J. Shoben (1997) proposed that concepts are combined via external relations and that lexical entries include information about which relations are frequent for every modifying noun. As evidence for this view, they showed that relations associated with the modifier affected the interpretation of combinations in several studies in…

  12. Relations among low ionosphere parameters and high frequency radio wave absorption

    Science.gov (United States)

    Cipriano, J. P.

    1973-01-01

    Charged particle conductivities measured in the very low ionosphere at White Sands Missile Range, New Mexico, and Wallops Island, Virginia, are compared with atmospheric parameters and high frequency radio wave absorption measurements. Charged particle densities are derived from the conductivity data. Between 33 and 58 km, positive conductivity correlated well with neutral atmospheric temperature, with temperature coefficients as large as 4.6%/deg K. Good correlations were also found between HF radio wave absorption and negative conductivity at altitudes as low as 53 km, indicating that the day-to-day absorption variations were principally due to variations in electron loss rate.

  13. Optical Frequency Optimization of a High Intensity Laser Power Beaming System Utilizing VMJ Photovoltaic Cells

    Science.gov (United States)

    Raible, Daniel E.; Dinca, Dragos; Nayfeh, Taysir H.

    2012-01-01

    An effective form of wireless power transmission (WPT) has been developed to enable extended mission durations, increased coverage and added capabilities for both space and terrestrial applications that may benefit from optically delivered electrical energy. The high intensity laser power beaming (HILPB) system enables long range optical 'refueling" of electric platforms such as micro unmanned aerial vehicles (MUAV), airships, robotic exploration missions and spacecraft platforms. To further advance the HILPB technology, the focus of this investigation is to determine the optimal laser wavelength to be used with the HILPB receiver, which utilizes vertical multi-junction (VMJ) photovoltaic cells. Frequency optimization of the laser system is necessary in order to maximize the conversion efficiency at continuous high intensities, and thus increase the delivered power density of the HILPB system. Initial spectral characterizations of the device performed at the NASA Glenn Research Center (GRC) indicate the approximate range of peak optical-to-electrical conversion efficiencies, but these data sets represent transient conditions under lower levels of illumination. Extending these results to high levels of steady state illumination, with attention given to the compatibility of available commercial off-the-shelf semiconductor laser sources and atmospheric transmission constraints is the primary focus of this paper. Experimental hardware results utilizing high power continuous wave (CW) semiconductor lasers at four different operational frequencies near the indicated band gap of the photovoltaic VMJ cells are presented and discussed. In addition, the highest receiver power density achieved to date is demonstrated using a single photovoltaic VMJ cell, which provided an exceptionally high electrical output of 13.6 W/sq cm at an optical-to-electrical conversion efficiency of 24 percent. These results are very promising and scalable, as a potential 1.0 sq m HILPB receiver of

  14. Elevated frequencies of circulating Th22 cell in addition to Th17 cell and Th17/Th1 cell in patients with acute coronary syndrome.

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    Full Text Available BACKGROUND: Atherosclerosis is a chronic inflammatory disease mediated by immune cells. Th22 cells are CD4(+ T cells that secret IL-22 but not IL-17 or IFN-γ and are implicated in the pathogenesis of inflammatory disease. The roles of Th22 cells in the pathophysiologic procedures of acute coronary syndrome (ACS remain unclear. The purpose of this study is to investigate the profile of Th22, Th17 and Th17/Th1 cells in ACS patients, including unstable angina (UA and acute myocardial infarction (AMI patients. DESIGN AND METHODS: In this study, 26 AMI patients, 16 UA patients, 16 stable angina (SA patients and 16 healthy controls were included. The frequencies of Th22, Th17 and Th17/Th1 cells in AMI, UA, SA patients and healthy controls were examined by flow cytometry. Plasma levels of IL-22, IL-17 and IFN-γ were measured by enzyme-linked immunosorbent assay (ELISA. RESULTS: Th22, Th17 and Th17/Th1 cells were significantly increased in AMI and UA patients compared with SA patients and healthy controls. Moreover, plasma IL-22 level was significantly elevated in AMI and UA patients. In addition, Th22 cells correlated positively with IL-22 as well as Th17 cells in AMI and UA patients. CONCLUSION: Our findings showed increased frequencies of both Th22 and Th17 cells in ACS patients, which suggest that Th22 and Th17 cells may play a potential role in plaque destabilization and the development of ACS.

  15. Frequency of head-impact-related outcomes by position in NCAA division I collegiate football players.

    Science.gov (United States)

    Baugh, Christine M; Kiernan, Patrick T; Kroshus, Emily; Daneshvar, Daniel H; Montenigro, Philip H; McKee, Ann C; Stern, Robert A

    2015-03-01

    Concussions and subconcussive impacts sustained in American football have been associated with short- and long-term neurological impairment, but differences in head impact outcomes across playing positions are not well understood. The American Medical Society for Sports Medicine has identified playing position as a key risk factor for concussion in football and one for which additional research is needed. This study examined variation in head impact outcomes across primary football playing positions in a group of 730 National Collegiate Athletic Association Division I Football Championship Series athletes, using a self-report questionnaire. Although there were no significant differences between position groups in the number of diagnosed concussions during the 2012 football season, there were significant differences between groups in undiagnosed concussions (p=0.008) and "dings" (pfootball season, with offensive linemen reporting significantly more symptoms compared to most other groups. There were also positional differences in frequency of returning to play while symptomatic (p<0.001) and frequency of participating in full-contact practice (p<0.001). Offensive linemen reported having returned to play while experiencing symptoms more frequently and participating in more full-contact practices than other groups. These findings suggest that offensive linemen, a position group that experiences frequent, but low-magnitude, head impacts, develop more postimpact symptoms than other playing positions, but do not report these symptoms as a concussion.

  16. Cryogenic optical lattice clocks with a relative frequency difference of $1\\times 10^{-18}$

    CERN Document Server

    Ushijima, Ichiro; Das, Manoj; Ohkubo, Takuya; Katori, Hidetoshi

    2014-01-01

    Time and frequency are the most accurately measurable quantities, providing foundations for science and modern technologies. The accuracy relies on the SI (Syst\\'eme International) second that refers to Cs microwave clocks with fractional uncertainties at $10^{-16}$. Recent revolutionary progress of optical clocks aims to achieve $1\\times 10^{-18}$ uncertainty, which however has been hindered by long averaging-times or by systematic uncertainties. Here, we demonstrate optical lattice clocks with $^{87}$Sr atoms interrogated in a cryogenic environment to address the blackbody radiation-induced frequency-shift, which remains the primary source of clocks' uncertainties and has initiated vigorous theoretical and experimental investigations. The quantum-limited stability for $N \\sim 1,000$ atoms allows investigation of the uncertainties at $2\\times 10^{-18}$ in two hours of clock operation. After 11 measurements performed over a month, the two cryo-clocks agree to within $(-1.1\\pm 1.6)\\times 10^{-18}$. Besides its...

  17. Cloud and convection frequencies over the southeast United States as related to small-scale geographic features

    Science.gov (United States)

    Gibson, Harold M.; Vonder Haar, Thomas H.

    1990-01-01

    Based on relatively high spatial and temporal resolution satelite data collected at 0700 CST and at each hour from 1000 CST to 1700 CST during the summer of 1986, cloud and convection variations over the area from Mississippi east to Georgia and from the Gulf of Mexico north to Tennessee are discussed. The data analyses show an average maximum cloud frequency over the land areas at 1400 local time and a maximum of deep convection one hour later. Both cloudiness and deep convection are found to be at a maximum during the nocturnal hours over the Gulf of Mexico. Cloud frequency shows a strong relationship to small terrain features. Small fresh water bodies have cloud minima relative to the surroundings in the afternoon hours. Higher, steep terrain shows cloud maxima and the adjacent lower terrain exhibits afternoon cloud minima due to a divergence of mountain breeze caused by the valley.

  18. FOXP3+ regulatory T cells in autoimmune hepatitis are fully functional and not reduced in frequency

    NARCIS (Netherlands)

    Peiseler, M.; Sebode, M.; Franke, B.; Wortmann, F.; Schwinge, D.; Quaas, A.; Baron, U.; Olek, S.; Wiegard, C.; Lohse, A.W.; Weiler-Normann, C.; Schramm, C.; Herkel, J.

    2012-01-01

    BACKGROUND & AIMS: The pathogenesis of autoimmune hepatitis (AIH) is not understood, but it was suggested that AIH may be related to a numerical or functional impairment of CD4+CD25+FOXP3+ regulatory T cells (Treg), which are important mediators of immune tolerance to self-antigens. However, the rol

  19. The relative frequency of odontogenic tumors in the Black Sea region of Turkey: an analysis of 86 cases

    OpenAIRE

    ŞENEL, Figen ÇİZMECİ; DAYISOYLU, Ezher Hamza; ERSÖZ, Şafak; ALTINTAŞ, Nuray YILMAZ; TOSUN, Emre; Üngör, Cem; Taşkesen, Fatih

    2011-01-01

    To determine the relative frequency and distribution of different types of odontogenic tumors in southeastern Europe, focusing on the Black Sea region of Turkey. Materials and methods: In total 1165 oromaxillofacial biopsy records were evaluated for histologic diagnosis of odontogenic tumors over a 7-year period from patients referred to the Department of Oral and Maxillofacial Surgery and Department of Pathology, Karadeniz Technical University, Faculty of Dentistry and Medicine, Trabzon, T...

  20. Relative validity and reproducibility of a food frequency questionnaire to assess dietary fiber intake in Danish adults

    OpenAIRE

    Vuholm, Stine; Lorenzen, Janne K.; Kristensen, Mette

    2014-01-01

    Background: Differences in habitual dietary fiber intake may modify effects of dietary fiber interventions, thus measurement of habitual dietary fiber intake is relevant to apply in intervention studies on fiber-rich foods, and food frequency questionnaire (FFQ) is a commonly used method. Rye bread is the major contributor of dietary fiber in the Danish population, and a nation-specific FFQ is therefore needed.Objective: The aim of this study was to assess the relative validity and reproducib...

  1. Deficient regulatory T cell activity and low frequency of IL-17-producing T cells correlate with the extent of cardiomyopathy in human Chagas' disease.

    Directory of Open Access Journals (Sweden)

    Paulo Marcos Matta Guedes

    Full Text Available BACKGROUND: Myocardium damage during Chagas' disease results from the immunological imbalance between pro- and production of anti-inflammatory cytokines and has been explained based on the Th1-Th2 dichotomy and regulatory T cell activity. Recently, we demonstrated that IL-17 produced during experimental T. cruzi infection regulates Th1 cells differentiation and parasite induced myocarditis. Here, we investigated the role of IL-17 and regulatory T cell during human Chagas' disease. METHODOLOGY/PRINCIPAL FINDINGS: First, we observed CD4(+IL-17(+ T cells in culture of peripheral blood mononuclear cells (PBMC from Chagas' disease patients and we evaluated Th1, Th2, Th17 cytokine profile production in the PBMC cells from Chagas' disease patients (cardiomyopathy-free, and with mild, moderate or severe cardiomyopathy cultured with T. cruzi antigen. Cultures of PBMC from patients with moderate and severe cardiomyopathy produced high levels of TNF-α, IFN-γ and low levels of IL-10, when compared to mild cardiomyopathy or cardiomyopathy-free patients. Flow cytometry analysis showed higher CD4(+IL-17(+ cells in PBMC cultured from patients without or with mild cardiomyopathy, in comparison to patients with moderate or severe cardiomyopathy. We then analyzed the presence and function of regulatory T cells in all patients. All groups of Chagas' disease patients presented the same frequency of CD4(+CD25(+ regulatory T cells. However, CD4(+CD25(+ T cells from patients with mild cardiomyopathy or cardiomyopathy-free showed higher suppressive activity than those with moderate and severe cardiomyopathy. IFN-γ levels during chronic Chagas' disease are inversely correlated to the LVEF (P = 0.007, r = -0.614, while regulatory T cell activity is directly correlated with LVEF (P = 0.022, r = 0.500. CONCLUSION/SIGNIFICANCE: These results indicate that reduced production of the cytokines IL-10 and IL-17 in association with high levels of IFN-γ and TNF

  2. Patterns of expression of cell wall related genes in sugarcane

    Directory of Open Access Journals (Sweden)

    Lima D.U.

    2001-01-01

    Full Text Available Our search for genes related to cell wall metabolism in the sugarcane expressed sequence tag (SUCEST database (http://sucest.lbi.dcc.unicamp.br resulted in 3,283 reads (1% of the total reads which were grouped into 459 clusters (potential genes with an average of 7.1 reads per cluster. To more clearly display our correlation coefficients, we constructed surface maps which we used to investigate the relationship between cell wall genes and the sugarcane tissues libraries from which they came. The only significant correlations that we found between cell wall genes and/or their expression within particular libraries were neutral or synergetic. Genes related to cellulose biosynthesis were from the CesA family, and were found to be the most abundant cell wall related genes in the SUCEST database. We found that the highest number of CesA reads came from the root and stem libraries. The genes with the greatest number of reads were those involved in cell wall hydrolases (e.g. beta-1,3-glucanases, xyloglucan endo-beta-transglycosylase, beta-glucosidase and endo-beta-mannanase. Correlation analyses by surface mapping revealed that the expression of genes related to biosynthesis seems to be associated with the hydrolysis of hemicelluloses, pectin hydrolases being mainly associated with xyloglucan hydrolases. The patterns of cell wall related gene expression in sugarcane based on the number of reads per cluster reflected quite well the expected physiological characteristics of the tissues. This is the first work to provide a general view on plant cell wall metabolism through the expression of related genes in almost all the tissues of a plant at the same time. For example, developing flowers behaved similarly to both meristematic tissues and leaf-root transition zone tissues. Besides providing a basis for future research on the mechanisms of plant development which involve the cell wall, our findings will provide valuable tools for plant engineering in the

  3. Relating soil pore geometry to soil water content dynamics decomposed at multiple frequencies

    Science.gov (United States)

    Qin, Mingming; Gimenez, Daniel; Cooper, Miguel

    2016-04-01

    Soil structure is a critical factor determining the response of soil water content to meteorological inputs such as precipitation. Wavelet analysis can be used to filter a signal into several wavelet components, each characterizing a given frequency. The purpose of this research was to investigate relationships between the geometry of soil pore systems and the various wavelet components derived from soil water content dynamics. The two study sites investigated were located in the state of São Paulo, Brazil. Each site was comprised of five soil profiles, the first site was situated along a 300-meter transect with about 10% slope in a tropical semi-deciduous forest, while the second one spanned 230-meter over a Brazilian savanna with a slope of about 6%. For each profile, between two to four Water Content Reflectometer CS615 (Campbell Scientific, Inc.) probes were installed according to horizonation at depths varying between 0.1 m and 2.3 m. Bulk soil, three soil cores, and one undisturbed soil block were sampled from selected horizons for determining particle size distributions, water retention curves, and pore geometry, respectively. Pore shape and size were determined from binary images obtained from resin-impregnated blocks and used to characterize pore geometry. Soil water contents were recorded at a 20-minute interval over a 4-month period. The Mexican hat wavelet was used to decompose soil water content measurements into wavelet components. The responses of wavelet components to wetting and drying cycles were characterized by the median height of the peaks in each wavelet component and were correlated with particular pore shapes and sizes. For instance, large elongated and irregular pores, largely responsible for the transmission of water, were significantly correlated with wavelet components at high frequencies (40 minutes to 48 hours) while rounded pores, typically associated to water retention, were only significantly correlated to lower frequency ranges

  4. Impact of frequency modulation ratio on capacitor cells balancing in phase-shifted PWM based chain-link STATCOM

    DEFF Research Database (Denmark)

    Behrouzian, Ehsan; Bongiorno, Massimo; Teodorescu, Remus

    2014-01-01

    The purpose of this paper is to investigate the impact of switching harmonics on the instantaneous power that flows in the cells of a chain-link based STATCOM when using Phase-Shifted PWM. Two different cases are investigated for the converter cells: low, and high switching frequency. It is shown...

  5. Linguistic tone is related to the population frequency of the adaptive haplogroups of two brain size genes, ASPM and Microcephalin.

    Science.gov (United States)

    Dediu, Dan; Ladd, D Robert

    2007-06-26

    The correlations between interpopulation genetic and linguistic diversities are mostly noncausal (spurious), being due to historical processes and geographical factors that shape them in similar ways. Studies of such correlations usually consider allele frequencies and linguistic groupings (dialects, languages, linguistic families or phyla), sometimes controlling for geographic, topographic, or ecological factors. Here, we consider the relation between allele frequencies and linguistic typological features. Specifically, we focus on the derived haplogroups of the brain growth and development-related genes ASPM and Microcephalin, which show signs of natural selection and a marked geographic structure, and on linguistic tone, the use of voice pitch to convey lexical or grammatical distinctions. We hypothesize that there is a relationship between the population frequency of these two alleles and the presence of linguistic tone and test this hypothesis relative to a large database (983 alleles and 26 linguistic features in 49 populations), showing that it is not due to the usual explanatory factors represented by geography and history. The relationship between genetic and linguistic diversity in this case may be causal: certain alleles can bias language acquisition or processing and thereby influence the trajectory of language change through iterated cultural transmission.

  6. Frequency of and risk factors for preventable medication-related hospital admissions in the Netherlands

    NARCIS (Netherlands)

    Leendertse, Anne J.; Egberts, Antoine C. G.; Stoker, Lennart J.; van den Bemt, Patricia M. L. A.

    2008-01-01

    Background: Medication-related problems that lead to hospitalization have been the subject of many studies, many of which were limited to 1 hospital or lacked patient follow-up. Furthermore, little information exists on potential risk factors associated with preventable medication-related hospitaliz

  7. Processing of Relative Clauses is Made Easier by Frequency of Occurrence

    Science.gov (United States)

    Reali, Florencia; Christiansen, Morten H.

    2007-01-01

    We conducted a large-scale corpus analysis indicating that pronominal object relative clauses are significantly more frequent than pronominal subject relative clauses when the embedded pronoun is personal. This difference was reversed when impersonal pronouns constituted the embedded noun phrase. This pattern of distribution provides a suitable…

  8. Neutronic flux stability of production uranium graphite reactor conversion core relative to high-frequency oscillations

    International Nuclear Information System (INIS)

    Preliminary methodical simplified investigation into stability of the neutron field in the conversion load of industrial uranium-graphite reactors with regard to basic characteristics of the load in transient processes was carried out. Analysis was based on the calculated research into the behaviour of simplified single-point and one-dimensional models of the reactor core in transient regimes during the interconnected description of dynamics of neutron-physical and thermal properties of the load. Fundamental assumptions on the reactor characteristics used in the calculated model. In the context of accepted approximations the obtained results preclude the possibility for the occurrence of spontaneous high frequency oscillations resulting from the positive reactivity effect on the fuel temperature in the conversion load

  9. Examining Online Shopping Services in Relation to Experience and Frequency of Using Internet Retailing

    Directory of Open Access Journals (Sweden)

    Alin OPREANA

    2013-12-01

    Full Text Available E-shopping has the potential to replace traditional in-store shopping. It is well perceived that information and communication technologies have great impacts on modern society - they are changing how and where we work, shop, and in general terms how we live our lives. In this study, we use a survey instrument to examine the association between experience level with Internet and e-shopping and consumers’ frequency of online purchasing, while considering sex as a passive influencer. We study these relationships in a multinomial logistic regression model that is aimed at online retailers to help them improve their understanding of their consumers’ characteristics and propensity to buy through Internet retailing. Tracking the online journey of consumers will help enhance the attractiveness of this new retailing medium to current and potential customers.

  10. Substituent Effects on the Low-Frequency Vibrational Modes of Benzoic Acid and Related Compounds

    Institute of Scientific and Technical Information of China (English)

    GE Min; ZHAO Hong-Wei; WANG Wen-Feng; YU Xiao-Han; LI Wen-Xin

    2007-01-01

    Well-resolved absorption spectra of benzoic acid and its derivatives with one hydrogen atom replaced by a substituent group CH3, OH, NH2 or NO2 were reported in the frequency region between 6 and 67 cm-1 at room temperature with terahertz time-domain spectroscopy (THz-TDS). These substances can be distinguished easily based on the terahertz absorption spectra. The measurements suggested that even minor changes in the molecular configuration and chemical composition lead to distinct differences in THz spectrum. Density functional theory (DFT)method was used to assist the analysis and assignment of the individual THz absorption spectra of benzoic acid and its methyl derivatives. Observed THz responses of samples can be assigned to the collective vibrations associated with intermolecular hydrogen bonds.

  11. Transition Frequencies and Negative Resistance of Inductively Terminated CMOS Buffer Cell and Application in MMW LC VCO

    Directory of Open Access Journals (Sweden)

    S. M. Rezaul Hasan

    2010-01-01

    looking into the source of the buffer cell changes sign. Possible limiting frequencies of oscillation are determined based on resonators formed by a grounded gate inductor and a parasitic capacitance at the gate of the negative resistance buffer cell. The range of frequencies of oscillation of this negative resistance buffer cell for variations in the different circuit parameters/elements is explored. Following this, a millimeter wave (MMW oscillator is simulated using the IBM 130 nm CMOS process technology which can operate at 70 GHz. High-frequency MOSFET model was used for these simulations. The cell had an extremely low power dissipation of under 3 mW. Extensive Monte Carlo simulations were carried out for manufacturability analysis considering up to 50% variation in process and geometrical parameters, supply voltage, and ambient temperature. Noise analysis and a simulated estimate of the phase noise in an MMW LC VCO application is also reported.

  12. X-ray sensitive strains of CHO cells show decreased frequency of stable transfection

    International Nuclear Information System (INIS)

    Six X-ray sensitive (xrs) strains of the Chinese hamster ovary cell line have previously been isolated and shown to have a defect in double strand break rejoining. In this study, these strains have been investigated for their ability to take up and integrate foreign DNA. All the xrs strains investigated so far have shown a decreased frequency of stable transfectants compared to their parent line, in experiments using the plasmid pSV2gpt, which contains the selectable bacterial gene, guanine phosphoribosyl transferase. This decreased frequency is observed over a wide range of DNA concentrations (0.1 to 20 μg DNA) but is more pronounced at higher DNA concentrations. In contrast, these xrs strains show the same level of transfection proficiency as the wild type parent using a transient transfection system with a plasmid containing the bacterial CAT (chloramphenicol acetyl transferase) gene. Since the level of CAT activity does not depend on integration of foreign DNA, this suggests that the xrs strains are able to take up the same amount of DNA as the parent strains, but have a defect in the integration of foreign DNA. Since this integration of foreign DNA probably occurs by non-homologous recombination, this may indicate a role of the xrs gene product in this process

  13. Combined space and alertness related therapy of visual hemineglect: effect of therapy frequency

    OpenAIRE

    Ferdinand Binkofski; Fink, Gereon R.; Jutta Kuest; Hans Karbe; Klaus F Willmes

    2013-01-01

    The combined efficacy of space- and alertness related training in chronic hemineglect was tested behaviorally and in a longitudinal fMRI study. Earlier results had shown that both space as well as alertness related training as single intervention methods lead to short term improvement which, however, is not stable for longer time periods. The neurobiological data obtained in these studies revealed differential cortical reorganization patterns for the two training approaches thereby leading to...

  14. Aberrant methylation frequency of TNFRSF10C promoter in pancreatic cancer cell lines

    Institute of Scientific and Technical Information of China (English)

    Hui-Hua Cai; Yue-Ming Sun; Yi Miao; Wen-Tao Gao; Quan Peng; JieYao; Han-Lin Zhao

    2011-01-01

    BACKGROUND: A growing body of evidence suggests that many tumors are initiated by both epigenetic abnormalities and gene mutations, which promote tumor progression. Epigenetic abnormalities include changes in DNA methylation and in the modification of histones. This study aimed to assess the status of methylation in the CpG island (CGI) of the tumor necrosis factor receptor superfamily member 10c (TNFRSF10C) with combined bisulfite restriction analysis (COBRA) and to evaluate its role in the progression of pancreatic cancer (PC). METHODS: The methylation status of four PC cell lines was assessed using COBRA and/or bisulfite genomic sequencing (BGS). Changes in methylation and TNFRSF10C expression in PC cell lines before and after treatment with 5-aza-2'-deoxycytidine (5-aza-dC) and/or trichostatin A (TSA) were assessed by BGS and real-time RT-PCR. Apoptosis in the four cell lines was tested by flow cytometry (FCM) and TUNEL assay. RESULTS: The methylation status of the TNFRSF10C promoter was assessed in PC cells (BxPC-3: 68.84±8.71%; CFPAC-1: 0;PANC-1: 96.77±4.57%; SW1990: 54.97±7.33%) with the COBRA assay, which was confirmed by the results of BGS. After treatment with 5-aza-dC and/or TSA, apoptosis was induced in PC cells to different degrees, and the levels of TNFRSF10C transcriptional expression in the PC cell lines (except CFPAC-1) increased markedly after 5-aza-dC treatment. CONCLUSIONS: A high frequency of CGI methylation in the TNFRSF10C promoter results in inactivation of the gene and enhancement of tumor growth in most PC cell lines (except CFPAC-1). Inactivation of TNFRSF10C by CGI hypermethylation can play an important role in PC progression and be potentially useful as a diagnostic marker and a new therapeutic approach for PC.

  15. Fear conditioning-related changes in cerebellar Purkinje cell activities in goldfish

    Directory of Open Access Journals (Sweden)

    Yoshida Masayuki

    2012-10-01

    Full Text Available Abstract Background Fear conditioning-induced changes in cerebellar Purkinje cell responses to a conditioned stimulus have been reported in rabbits. It has been suggested that synaptic long-term potentiation and the resulting increases in firing rates of Purkinje cells are related to the acquisition of conditioned fear in mammals. However, Purkinje cell activities during acquisition of conditioned fear have not been analysed, and changes in Purkinje cell activities throughout the development of conditioned fear have not yet been investigated. In the present study, we tracked Purkinje cell activities throughout a fear conditioning procedure and aimed to elucidate further how cerebellar circuits function during the acquisition and expression of conditioned fear. Methods Activities of single Purkinje cells in the corpus cerebelli were tracked throughout a classical fear conditioning procedure in goldfish. A delayed conditioning paradigm was used with cardiac deceleration as the conditioned response. Conditioning-related changes of Purkinje cell responses to a conditioned stimulus and unconditioned stimulus were examined. Results The majority of Purkinje cells sampled responded to the conditioned stimulus by either increasing or decreasing their firing rates before training. Although there were various types of conditioning-related changes in Purkinje cells, more than half of the cells showed suppressed activities in response to the conditioned stimulus after acquisition of conditioned fear. Purkinje cells that showed unconditioned stimulus-coupled complex-spike firings also exhibited conditioning-related suppression of simple-spike responses to the conditioned stimulus. A small number of Purkinje cells showed increased excitatory responses in the acquisition sessions. We found that the magnitudes of changes in the firing frequencies of some Purkinje cells in response to the conditioned stimulus correlated with the magnitudes of the conditioned

  16. Frequency of myasthenic crisis in relation to thymectomy in generalized myasthenia gravis: A 17-year experience

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    Shalmani Hamidreza

    2004-09-01

    Full Text Available Abstract Background Myasthenic crisis is the most serious life-threatening event in generalized myasthenia gravis (MG patients. The objective of this study was to assess the long-term impact of thymectomy on rate and severity of these attacks in Iranian patients. Methods We reviewed the clinical records from 272 myasthenic patients diagnosed and treated in our neurology clinic during 1985 to 2002. Fifty-three patients were excluded because of unconfirmed diagnosis, ocular form of MG, contraindication to surgery, concomitant diseases and loss to follow-up. The Osserman classification was used to assess the initial severity of the disease. Frequency and severity of the attacks were compared between two groups with appropriate statistical tests according to the nature of variables. Multivariate logistic regression analysis was used to assess the predictors of myasthenic crisis in the group of patients without thymoma. Results 110 patients were in thymectomy group and the other 109 patients were on medical therapy. These two groups had no significant differences with respect to age at onset, gender, Osserman score in baseline and follow up period. 62 patients (28.3% of all 219 patients had reported 89 attacks of myasthenic crisis. 20 patients of 62 (32% were in thymectomy group and 42 (68% were in the other group. There was significant difference between the two groups in number of patients with crisis (P = 0.001; odds ratio = 2.8 with 95% CI of 1.5 to 5.2. In addition, these attacks were more severe in group of non-thymectomized patients as the duration of ICU admission was longer and they needed more ventilatory support during their attacks. Regression model showed thymectomy and lower age at onset as two predictors of decrement in myasthenic crisis rate in non-thymomatous MG patients. Conclusions It is suggested that frequency and severity of myasthenic attacks as important endpoints in evaluation of MG patients. Thymectomy seems to have a

  17. Very high frequency plasma deposited amorphous/nanocrystalline silicon tandem solar cells on flexible substrates

    Science.gov (United States)

    Liu, Y.

    2010-02-01

    The work in this thesis is to develop high quality intrinsic layers (especially nc-Si:H) for micromorph silicon tandem solar cells/modules on plastic substrates following the substrate transfer method or knows as the Helianthos procedure. Two objectives are covered in this thesis: (1) preliminary work on trial and optimization of single junction and tandem cells on glass substrate, (2) silicon film depositions on Al foil, and afterwards the characterization and development of these cells/modules on a plastic substrate. The first objective includes the development of suitable ZnO:Al TCO for nc Si:H single junction solar cells, fabrication of the aimed micromorph tandem solar cells on glass, and finally the optimization of the nc-Si:H i-layer for the depositions afterwards on Al foil. Chapter 3 addresses the improvement of texture etching of ZnO:Al by studying the HCl etching effect on ZnO:Al films sputter-deposited in a set substrate heater temperature series. With the texture-etched ZnO:Al front TCO, a single junction nc-Si:H solar cell was deposited with an initial efficiency of 8.33%. Chapter 4 starts with studying the light soaking and annealing effects on micromorph tandem solar cell. In the end, a highly stabilized bottom cell current limited tandem cell was made. The tandem shows an initial efficiency of 10.2%, and degraded only 6.9% after 1600 h of light soaking. In Chapter 5, the nc-Si:H i-layers were studied in 3 pressure and inter-electrode distance series. The correlations between plasma physics and the consequent i-layers’ properties are investigated. We show that the Raman crystalline ratio and porosity of the nc-Si:H layer have an interesting relation with the p•d product. By varying p and d, device quality nc-Si:H layer can be deposited at a high rate of 0.6 nm/s. These results in fact are a very important step for the second objective. The second objective is covered by the entire Chapter 6. All silicon layers are deposited on special aluminum

  18. Bi facial silicon solar cell study in modelling in frequency dynamic regime under multispectral illumination: Recombination parameters determination methods

    International Nuclear Information System (INIS)

    A bibliographic study on the techniques of characterization of silicon solar cell, diodes, massifs and silicon wafer are presented. The influence of the modulation frequency and recombination in volume and in surface phenomena of on the profiles of carriers' densities, photocurrent and photovoltage has been put in evidence. The study of surface recombination velocities permitted to show that the bi facial silicon solar cell of Back Surface Field type behaves like an ohmic contacts solar cell for modulation frequencies above 40 khz. pplicability in frequency dynamic regime in the frequency range [0 - 40 khz] of three techniques of steady state recombination parameters determination is shown. A technique of diffusion length determination, in the range of (200 Hz - 40 khz] is proposed. It rests on the measurement of the short circuit current phase that is compared with the theoretical curve of short circuit current phase. The intersection of the experimental short circuit current phase and the theoretical curve of short circuit current phase permits to get the minority carriers effective diffusion length. An equivalent electric model of a solar cell in frequency dynamic regime is proposed. A study in modelling of the bi facial solar cell shunt resistance and space charge zone capacity is led from a determination method of these parameters proposed in steady state. (Author

  19. The effect of hair bundle shape on hair bundle hydrodynamics of inner ear hair cells at low and high frequencies.

    Science.gov (United States)

    Shatz, L F

    2000-03-01

    The relationship between size and shape of the hair bundle of a hair cell in the inner ear and its sensitivity at asymptotically high and low frequencies was determined, thereby extending the results of an analysis of hair bundle hydrodynamics in two dimensions (Freeman and Weiss, 1990. Hydrodynamic analysis of a two-dimensional model for micromechanical resonance of free-standing hair bundles. Hear. Res. 48, 37-68) to three dimensions. A hemispheroid was used to represent the hair bundle. The hemispheroid had a number of advantages: it could represent shapes that range from thin, pencil-like shapes, to wide, flat, disk-like shapes. Also analytic methods could be used in the high frequency range to obtain an exact solution to the equations of motion. In the low frequency range, where an approximate solution was found using boundary element methods, the sensitivity of the responses of hair cells was mainly proportional to the cube of the heights of their hair bundles, and at high frequencies, the sensitivity of the hair cells was mainly proportional to the inverse of their heights. An excellent match was obtained between measurements of sensitivity curves in the basillar papilla of the alligator and bobtail lizards and the model's predictions. These results also suggest why hair bundles of hair cells in vestibular organs which are sensitive to low frequencies have ranges of heights that are an order of magnitude larger than the range of heights of hair bundles of hair cells found in auditory organs.

  20. Frequency of Occurrence of Pregnancy in Relation to Uterine Horn in Cattle in the Colombian Tropics

    Directory of Open Access Journals (Sweden)

    Marco González Tous

    2014-07-01

    Full Text Available This paper aims to determine the frequency of occurrence of pregnancy in the right and left uterine horns of cattle in the Colombian tropics. Rectal palpation was performed in 1,534 cows to diagnose pregnancy and to indicate the pregnant horn (left or right. Additionally, 618 non-pregnant cows were examined to determine the presence of corpora lutea (CL or follicle (F, and to identify the ovary (right or left containing them. In pregnant cows, the percentages of right and left gestation were 63.1% (968/1534 and 36.9% (566/1534 (p ≤ 0.01, respectively, and in non-pregnant cows, 69 % of CL and 68% of F were found in the right ovary (p ≤ 0.01. Similarly, reproductive tracts of 300 pregnant cows were inspected, as well as those of 300 non-pregnant cows but with CL and F present. In pregnant tracts, the percentages of right and left gestation were 67.3% and 32.7% (p ≤ 0.01, respectively, and in non-pregnant cattle, 68% of CL and 65% of F were found in the right ovary (p ≤ 0.01. In conclusion, the highest percentage of pregnancies in cattle in the Colombian tropics is presented in the right horn; an increased presence of CL and F was also found in the right ovary.

  1. Frequency and Intensive Care Related Risk Factors of Pneumothorax in Ventilated Neonates

    Directory of Open Access Journals (Sweden)

    Ramesh Bhat Yellanthoor

    2014-01-01

    Full Text Available Objectives. Relationships of mechanical ventilation to pneumothorax in neonates and care procedures in particular are rarely studied. We aimed to evaluate the relationship of selected ventilator variables and risk events to pneumothorax. Methods. Pneumothorax was defined as accumulation of air in pleural cavity as confirmed by chest radiograph. Relationship of ventilator mode, selected settings, and risk procedures prior to detection of pneumothorax was studied using matched controls. Results. Of 540 neonates receiving mechanical ventilation, 10 (1.85% were found to have pneumothorax. Respiratory distress syndrome, meconium aspiration syndrome, and pneumonia were the underlying lung pathology. Pneumothorax mostly (80% occurred within 48 hours of life. Among ventilated neonates, significantly higher percentage with pneumothorax received mandatory ventilation than controls (70% versus 20%; P20 cm H2O and overventilation were not significantly associated with pneumothorax. More cases than controls underwent care procedures in the preceding 3 hours of pneumothorax event. Mean airway pressure change (P=0.052 and endotracheal suctioning (P=0.05 were not significantly associated with pneumothorax. Reintubation (P=0.003, and bagging (P=0.015 were significantly associated with pneumothorax. Conclusion. Pneumothorax among ventilated neonates occurred at low frequency. Mandatory ventilation and selected care procedures in the preceding 3 hours had significant association.

  2. The Relative Frequency, Clinical and Laboratory Findings of Adult Glomerulonephritidies in Tehran

    Directory of Open Access Journals (Sweden)

    Afsoon Emami Naini

    2006-05-01

    Full Text Available Background: Renal diseases information is population-based and has great geographic variability. Due to the lack of national renal data registry system, there is no information on the prevalence rate, and clinical and laboratory features of various glomerulonephritidies (GNs in Iran. Methods: In a retrospective cross sectional study, we analyzed 462 adult renal biopsies in Hashemi Nejad hospital, Tehran, Iran. We determined the prevalence rate and the frequency of different clinical and laboratory findings in patients with different GNs. We also compared our results with the reports from other countries. Results: There were 267(57.8% males and 195(42.2% females. The mean age (± SD was 33.6 ± 15.7 (range, 13-75 years old. After exclusion of 55 biopsies with pathologies other than GNs and in the remaining 407 biopsies, membranous glomerulopathy (MGN was the most common GN (23.6%, followed by IgAN (13.5%, membranoproliferative GN (11.5%, systemic lupus nephritis (10.6%, focal segmental glomerulosclerosis (10.3%, and minimal change disease (9.8%. These 6 GNs comprised the majority (79.4% of all GNs. Conclusion: MGN is the most common form of GN, followed by IgAN, MPGN, SLE-GN, FSGS and MCD in adult patients in our study. The multi-center studies with a larger sample size are needed for more comprehensive data in Iranian population. Key words: Glomerulonephritidies, Epidemiology, Renal Biopsy, Glomeulopathy

  3. MHC class I-related molecule, MR1, and mucosal-associated invariant T cells.

    Science.gov (United States)

    Franciszkiewicz, Katarzyna; Salou, Marion; Legoux, Francois; Zhou, Qian; Cui, Yue; Bessoles, Stéphanie; Lantz, Olivier

    2016-07-01

    The MHC-related 1, MR1, molecule presents a new class of microbial antigens (derivatives of the riboflavin [Vitamin B2] biosynthesis pathway) to mucosal-associated invariant T (MAIT) cells. This raises many questions regarding antigens loading and intracellular trafficking of the MR1/ligand complexes. The MR1/MAIT field is also important because MAIT cells are very abundant in humans and their frequency is modified in many infectious and non-infectious diseases. Both MR1 and the invariant TCRα chain expressed by MAIT cells are strikingly conserved among species, indicating important functions. Riboflavin is synthesized by plants and most bacteria and yeasts but not animals, and its precursor derivatives activating MAIT cells are short-lived unless bound to MR1. The recognition of MR1 loaded with these compounds is therefore an exquisite manner to detect invasive bacteria. Herein, we provide an historical perspective of the field before describing the main characteristics of MR1, its ligands, and the few available data regarding its cellular biology. We then summarize the current knowledge of MAIT cell differentiation and discuss the definition of MAIT cells in comparison to related subsets. Finally, we describe the phenotype and effector activities of MAIT cells. PMID:27319347

  4. Lonidamine Causes Inhibition of Angiogenesis-Related Endothelial Cell Functions

    OpenAIRE

    Donatella Del Bufalo; Daniela Trisciuoglio; Marco Scarsella; Giulia D'Amati; Antonio Candiloro; Angela Iervolino; Carlo Leonetti; Gabriella Zupi

    2004-01-01

    The aim of this study was to assess whether lonidamine (LND) interferes with some steps in angiogenesis progression. We report here, for the first time, that LND inhibited angiogenic-related endothelial cell functions in a dose-dependent manner (1-50 μg/ml). In particular, LND decreased proliferation, migration, invasion, and morphogenesis on matrigel of different endothelial cell lines. Zymographic and Western blot analysis assays showed that LND treatment produced a reduction in the secreti...

  5. Laser Frequency Stabilization for Coherent Lidar Applications using Novel All-Fiber Gas Reference Cell Fabrication Technique

    Science.gov (United States)

    Meras, Patrick, Jr.; Poberezhskiy, Ilya Y.; Chang, Daniel H.; Levin, Jason; Spiers, Gary D.

    2008-01-01

    Compact hollow-core photonic crystal fiber (HC-PCF)gas frequency reference cell was constructed using a novel packaging technique that relies on torch-sealing a quartz filling tube connected to a mechanical splice between regular and hollow-core fibers. The use of this gas cell for laser frequency stabilization was demonstrated by locking a tunable diode laser to the center of the P9 line from the (nu)1+(nu)3 band of acetylene with RMS frequency error of 2.06 MHz over 2 hours. This effort was performed in support of a task to miniaturize the laser frequency stabilization subsystem of JPL/LMCT Laser Absorption Spectrometer (LAS) instrument.

  6. Relating Single Cell Heterogeneity To Genotype During Cancer Progression

    Science.gov (United States)

    Rajaram, Satwik

    2013-03-01

    Progression of normal cells towards cancer is driven by a series of genetic changes. Traditional population-averaged measurements have found that cell signalling activities are increasingly altered during this progression. Despite the fact that cancer cells are known to be highly heterogeneous, the response of individual pathways to specific genetic changes remains poorly characterized at a single cell level. Do signalling alterations in a pathway reflect a shift of the whole population, or changes to specific subpopulations? Are alterations to pathways independent, or are cells with alterations in one pathway more likely to be abnormal in another due to crosstalk? We are building a computational framework that analyzes immunofluorescence microscopy images of cells to identify alterations in individual pathways at a single-cell level. A primary novelty of our approach is a ``change of basis'' that allows us to understand signalling in cancer cells in terms of the much better understood patterns of signalling in normal cells. This allows us to model heterogeneous populations of cancer cells as a mixture of distinct subpopulations, each with a specific combination of signalling pathways altered beyond the normal baseline. We used this framework to analyze human bronchial epithelial cell lines containing a series of genetic modifications commonly seen in lung cancer. We confirmed expected trends (such as a population-wide epithelial mesenchymal transition following the last of our series of modifications) and are presently studying the relation between the mutational profiles of cancer cells and pathway crosstalk. Our framework will help establish a more natural basis for future investigations into the phenotype-genotype relationship in heterogeneous populations.

  7. INVESTIGATION OF DOMINANT FREQUENCIES IN TRANSITION REYNOLDS NUMBER RANGE OF FLOW AROUND A CIRCULAR CYLINDER Ⅰ: EXPERIMENTAL STUDY OF THE RELATION BETWEEN VORTEX SHEDDING AND TRANSITION FREQUENCIES

    Institute of Scientific and Technical Information of China (English)

    AHMED N A

    2006-01-01

    A comprehensive hot wire investigation of the flow around a circular cylinder is carried out in an 18" × 18" wind tunnel to look into the dominant frequencies at the stagnation, separation and separated shear layers in the transition Reynolds number range. The majority of the experiments are carried out at Reynolds number of 4.5 × 104, with additional transition frequency tests at Reynolds numbers of 2.9 × 104, 3.3 × 104 and 9.7 × 104 respectively. The results are analysed in terms of power spectral density. While the frequency associated with stagnation is found to be essentially due to vortex shedding, frequency doubling of vortex shedding is also evident in the separated shear layers.Two peaks associated with transition frequencies are detected and their possible implications are presented.

  8. The Evolution of Frequency Distributions: Relating Regularization to Inductive Biases through Iterated Learning

    Science.gov (United States)

    Reali, Florencia; Griffiths, Thomas L.

    2009-01-01

    The regularization of linguistic structures by learners has played a key role in arguments for strong innate constraints on language acquisition, and has important implications for language evolution. However, relating the inductive biases of learners to regularization behavior in laboratory tasks can be challenging without a formal model. In this…

  9. Age-Related Reduced Somatosensory Gating Is Associated with Altered Alpha Frequency Desynchronization

    Directory of Open Access Journals (Sweden)

    Chia-Hsiung Cheng

    2015-01-01

    Full Text Available Sensory gating (SG, referring to an attenuated neural response to the second identical stimulus, is considered as preattentive processing in the central nervous system to filter redundant sensory inputs. Insufficient somatosensory SG has been found in the aged adults, particularly in the secondary somatosensory cortex (SII. However, it remains unclear which variables leading to the age-related somatosensory SG decline. There has been evidence showing a relationship between brain oscillations and cortical evoked excitability. Thus, this study used whole-head magnetoencephalography to record responses to paired-pulse electrical stimulation to the left median nerve in healthy young and elderly participants to test whether insufficient stimulus 1- (S1- induced event-related desynchronization (ERD contributes to a less-suppressed stimulus 2- (S2- evoked response. Our analysis revealed that the minimum norm estimates showed age-related reduction of SG in the bilateral SII regions. Spectral power analysis showed that the elderly demonstrated significantly reduced alpha ERD in the contralateral SII (SIIc. Moreover, it was striking to note that lower S1-induced alpha ERD was associated with higher S2-evoked amplitudes in the SIIc among the aged adults. Conclusively, our findings suggest that age-related decline of somatosensory SG is partially attributed to the altered S1-induced oscillatory activity.

  10. Frequency Affects Object Relative Clause Processing: Some Evidence in Favor of Usage-Based Accounts

    Science.gov (United States)

    Reali, Florencia

    2014-01-01

    The processing difficulty of nested grammatical structure has been explained by different psycholinguistic theories. Here I provide corpus and behavioral evidence in favor of usage-based models, focusing on the case of object relative clauses in Spanish as a first language. A corpus analysis of spoken Spanish reveals that, as in English, the…

  11. A validity study of self-reported daily texting frequency, cell phone characteristics, and texting styles among young adults

    OpenAIRE

    Gold, Judith E.; Rauscher, Kimberly J; Zhu, Motao

    2015-01-01

    Background Texting is associated with adverse health effects including musculoskeletal disorders, sleep disturbances, and traffic crashes. Many studies have relied on self-reported texting frequency, yet the validity of self-reports is unknown. Our objective was to provide some of the first data on the validity of self-reported texting frequency, cell phone characteristics including input device (e.g. touchscreen), key configuration (e.g., QWERTY), and texting styles including phone orientati...

  12. Epidural auditory event-related potentials in the rat to frequency and duration deviants: evidence of mismatch negativity?

    Directory of Open Access Journals (Sweden)

    Tamo eNakamura

    2011-12-01

    Full Text Available The capacity of the human brain to detect deviance in the acoustic environment pre-attentively is reflected in a brain event-related potential (ERP, mismatch negativity (MMN. MMN is observed in response to the presentation of rare oddball sounds that deviate from an otherwise regular pattern of frequent background standard sounds. While the primate and cat auditory cortex (AC exhibit MMN-like activity, it is unclear whether the rodent AC produces a deviant response that reflects deviance detection in a background of regularities evident in recent auditory stimulus history or differential adaptation of neuronal responses due to rarity of the deviant sound. We examined whether MMN-like activity occurs in epidural AC potentials in awake and anaesthetised rats to high and low frequency and long and short duration deviant sounds. ERPs to deviants were compared with ERPs to common standards and also with ERPs to deviants when interspersed with many different standards to control for background regularity effects. High frequency and long duration deviant ERPs in the awake rat showed evidence of deviance detection, consisting of negative displacements of the deviant ERP relative to ERPs to both common standards and deviants with many standards. The high frequency deviant MMN-like response was also sensitive to the extent of regularity in recent acoustic stimulation. Anaesthesia in contrast resulted in positive displacements of deviant ERPs. Our results suggest that epidural MMN-like potentials to high frequency sounds in awake rats encode deviance in an analogous manner to the human MMN, laying the foundation for animal models of disorders characterised by disrupted MMN generation, such as schizophrenia.

  13. Relative frequencies of the “sex-ratio” inversion in natural populations of Drosophila pseudoobscura from Mexico

    Directory of Open Access Journals (Sweden)

    Salceda Víctor M.

    2011-01-01

    Full Text Available Sex-ratio (proportion of males in a species is related to a not entirely explained mechanism of sex determination. In Drosophila, sex is determined by the proportion of X chromosomes vs. autosomes. A decrease in the proportion of males vs. females, known as sex-ratio, is characteristic to several Drosophila species, and is related to an inversion in the sexual chromosome the so called “sex-ratio” (SR condition. In this occasion we study the presence of that inversion in several populations of Drosophila pseudoobscura from Mexico. With this purpose we did collections of this species on Nevado de Colima,Col., Valparaíso, Zac, Zirahuén, Mich., Tulancingo, Hgo. and Amecameca, Mex. Flies were captured in nature and carried to the laboratory were individual cultures of each female were established, when the offsprig emerged salivary glands of a single larva from each culture were extracted and stained with an aceto-orcein solution and the corresponding genotype for the third and sex chromosome determined and their relative frequencies calculated. The corresponding frequencies of the “sex-ratio” inversion in the localities analyzed were: Nevado de Colima 21.8 %, Valparaiso 18.8 %, Zirahuén 11.4 %, Tulancingo 6.8 % and Amecameca 6.8 %. Apparently an East-West cline distribution is present in these populations. Relative frequencies for inversions in the third chomosome were recorded and relationships between third and X chromosomes inversions performed. Comparisons with similar studies on this and other species are pointed out.

  14. Ultrastructural Study of Alveolar Epithelial Type II Cells by High-Frequency Oscillatory Ventilation

    Directory of Open Access Journals (Sweden)

    Xiaofei Qin

    2013-01-01

    Full Text Available Alveolar epithelial type II cells (AECIIs containing lamellar bodies (LBs are alveolar epithelial stem cells that have important functions in the repair of lung structure and function after lung injury. The ultrastructural changes in AECIIs after high-frequency oscillatory ventilation (HFOV with a high lung volume strategy or conventional ventilation were evaluated in a newborn piglet model with acute lung injury (ALI. After ALI with saline lavage, newborn piglets were randomly assigned into five study groups (three piglets in each group, namely, control (no mechanical ventilation, conventional ventilation for 24 h, conventional ventilation for 48 h, HFOV for 24 h, and HFOV for 48 h. The lower tissues of the right lung were obtained to observe the AECII ultrastructure. AECIIs with reduced numbers of microvilli, decreased LBs electron density, and vacuole-like LBs deformity were commonly observed in all five groups. Compared with conventional ventilation groups, the decrease in numbers of microvilli and LBs electron density, as well as LBs with vacuole-like appearance and polymorphic deformity, was less severe in HFOV with high lung volume strategy groups. AECIIs were injured during mechanical ventilation. HFOV with a high lung volume strategy resulted in less AECII damage than conventional ventilation.

  15. A study of the effects of flux density and frequency of pulsed electromagnetic field on neurite outgrowth in PC12 cells.

    Science.gov (United States)

    Zhang, Yang; Ding, Jun; Duan, Wei

    2006-01-01

    The aim of this study was to investigate the influence of pulsed electromagnetic fields with various flux densities and frequencies on neurite outgrowth in PC12 rat pheochromocytoma cells. We have studied the percentage of neurite-bearing cells, average length of neurites and directivity of neurite outgrowth in PC12 cells cultured for 96 hours in the presence of nerve growth factor (NGF). PC12 cells were exposed to 50 Hz pulsed electromagnetic fields with a flux density of 1.37 mT, 0.19 mT and 0.016 mT respectively. The field was generated through a Helmholtz coil pair housed in one incubator and the control samples were placed in another identical incubator. It was found that exposure to both a relatively high flux density (1.37 mT) and a medium flux density (0.19 mT) inhibited the percentage of neurite-bearing cells and promoted neurite length significantly. Exposure to high flux density (1.37 mT) also resulted in nearly 20% enhancement of neurite directivity along the field direction. However, exposure to low flux density field (0.016 mT) had no detectable effect on neurite outgrowth. We also studied the effect of frequency at the constant flux density of 1.37 mT. In the range from 1 approximately 100 Hz, only 50 and 70 Hz pulse frequencies had significant effects on neurite outgrowth. Our study has shown that neurite outgrowth in PC12 cells is sensitive to flux density and frequency of pulsed electromagnetic field.

  16. Effect of frequency on the structure and cell response of Ca- and P-containing MAO films

    International Nuclear Information System (INIS)

    The Ca- and P-containing MAO films were prepared on titanium substrate at different frequencies (100-5000 Hz) and were characterized by SEM, XRD, XPS and contact angle goniometer. For in vitro test, the rat bone marrow mesenchymal stem cells (rMSCs) were seeded on the films. The fluorescence microscopy and the PicoGreen assay were used to determine the cell initial adhesion and proliferation. It shows that the frequency of the MAO affected the crystallinity, composition, morphology and wetting ability of the oxidation film. At a high frequency, the crystallinity decreased, and the content of Ca and P increased. The structure formed at a high frequency - there were many smaller pores on the wall of the larger ones and many inner pores in the film - could improve the connectivity of the film. The wetting ability of the film was also improved by increasing the frequency. The mechanism of how the frequency of the MAO process could influence the oxidation film was discussed. It could be explained by the theory of electron avalanche and the phenomenon of secondary breakdown. In vitro test showed that the film formed at 5000 Hz was more favorable for the initial cell attachment and proliferation.

  17. Fauna and relative frequency of synanthropic flies in the biggest Persian Gulf Island, Qeshm, Iran

    Institute of Scientific and Technical Information of China (English)

    Mehdi Khoobdel; Kamran Akbarzadeh; Javad Rafinejad

    2015-01-01

    Objective: To identify the diversity and relative abundance of medically important species of synanthropic flies and their seasonal activity on Qeshm Island in Persian Gulf, Iran. Methods: Flies collection was performed during March 2011 to February 2012 in all different areas of the island by using the common fly trap and plastic water bottle fly trap, reverse-cone model, containing tainted lamb or beef meat as bait. The captured flies were identified by using valid flies systematic keys, checklists and species description. The relative abundances and seasonal activity of flies were estimated by means of flies captured per trap in every month. Results: In this study a total number of 11 species of medically important flies in three families including Calliphoridae, Sarcophagidae and Muscidae, were collected. The relative mean abundance of flies was estimated to be 6.3 ± 1.1 per trap. The most abundance was seen in rural areas in the south of Qeshm Island with 10.1 ± 1.5 per trap. In this island, medically impotent flies had two peaks of activity in early spring and early autumn, during April and October. Flies activity decreased in July and August due to the high increase of temperature and humidity of the weather. In February, the relative decrease in air temperature reduced the activity of the flies. Conclusions: Diversity and abundance of flies in spring and early autumn were higher than other seasons, especially in rural areas of Southern Qeshm Island. Insect control measures should be conducted during the peak of flies activity.

  18. Fauna and relative frequency of synanthropic flies in the biggest Persian Gulf Island, Qeshm, Iran

    Directory of Open Access Journals (Sweden)

    Mehdi Khoobdel

    2015-09-01

    Full Text Available Objective: To identify the diversity and relative abundance of medically important species of synanthropic flies and their seasonal activity on Qeshm Island in Persian Gulf, Iran. Methods: Flies collection was performed during March 2011 to February 2012 in all different areas of the island by using the common fly trap and plastic water bottle fly trap, reverse-cone model, containing tainted lamb or beef meat as bait. The captured flies were identified by using valid flies systematic keys, checklists and species description. The relative abundances and seasonal activity of flies were estimated by means of flies captured per trap in every month. Results: In this study a total number of 11 species of medically important flies in three families including Calliphoridae, Sarcophagidae and Muscidae, were collected. The relative mean abundance of flies was estimated to be 6.3 ± 1.1 per trap. The most abundance was seen in rural areas in the south of Qeshm Island with 10.1 ± 1.5 per trap. In this island, medically impotent flies had two peaks of activity in early spring and early autumn, during April and October. Flies activity decreased in July and August due to the high increase of temperature and humidity of the weather. In February, the relative decrease in air temperature reduced the activity of the flies. Conclusions: Diversity and abundance of flies in spring and early autumn were higher than other seasons, especially in rural areas of Southern Qeshm Island. Insect control measures should be conducted during the peak of flies activity.

  19. Frequency of mutant T lymphocytes defective in the expression of the T-cell antigen receptor gene among radiation-exposed people

    International Nuclear Information System (INIS)

    The frequency of mutant T lymphocytes defective in T-cell receptor gene (α or β) expression was measured using the two-color flow cytometric technique. Results for a total of 203 atomic bomb survivors, 78 of whom were proximally exposed (DS86 doses of ≥ 1.5 Gy) and 125 of whom were distally exposed (DS86 doses of 228Th formerly used for radiodiagnosis. In addition, thyroid disease patients treated with 131I showed a dose-related increase of mutant frequency. It was suggested that the present T-cell receptor mutation assay has a unique characteristic as a biological dosimeter for the measurement of recent exposures to genotoxic agents. (author)

  20. Frequency-Dependent Representation of Reinforcement-Related Information in the Human Medial and Lateral Prefrontal Cortex.

    Science.gov (United States)

    Smith, Elliot H; Banks, Garrett P; Mikell, Charles B; Cash, Syndey S; Patel, Shaun R; Eskandar, Emad N; Sheth, Sameer A

    2015-12-01

    The feedback-related negativity (FRN) is a commonly observed potential in scalp electroencephalography (EEG) studies related to the valence of feedback about a subject's performance. This potential classically manifests as a negative deflection in medial frontocentral EEG contacts following negative feedback. Recent work has shown prominence of theta power in the spectral composition of the FRN, placing it within the larger class of "frontal midline theta" cognitive control signals. Although the dorsal anterior cingulate cortex (dACC) is thought to be the cortical generator of the FRN, conclusive data regarding its origin and propagation are lacking. Here we examine intracranial electrophysiology from the human medial and lateral prefrontal cortex (PFC) to better understand the anatomical localization and communication patterns of the FRN. We show that the FRN is evident in both low- and high-frequency local field potentials (LFPs) recorded on electrocorticography. The FRN is larger in medial compared with lateral PFC, and coupling between theta band phase and high-frequency LFP power is also greater in medial PFC. Using Granger causality and conditional mutual information analyses, we provide evidence that feedback-related information propagates from medial to lateral PFC, and that this information transfer oscillates with theta-range periodicity. These results provide evidence for the dACC as the cortical source of the FRN, provide insight into the local computation of frontal midline theta, and have implications for reinforcement learning models of cognitive control. PMID:26631465

  1. Frequency-Dependent Representation of Reinforcement-Related Information in the Human Medial and Lateral Prefrontal Cortex.

    Science.gov (United States)

    Smith, Elliot H; Banks, Garrett P; Mikell, Charles B; Cash, Syndey S; Patel, Shaun R; Eskandar, Emad N; Sheth, Sameer A

    2015-12-01

    The feedback-related negativity (FRN) is a commonly observed potential in scalp electroencephalography (EEG) studies related to the valence of feedback about a subject's performance. This potential classically manifests as a negative deflection in medial frontocentral EEG contacts following negative feedback. Recent work has shown prominence of theta power in the spectral composition of the FRN, placing it within the larger class of "frontal midline theta" cognitive control signals. Although the dorsal anterior cingulate cortex (dACC) is thought to be the cortical generator of the FRN, conclusive data regarding its origin and propagation are lacking. Here we examine intracranial electrophysiology from the human medial and lateral prefrontal cortex (PFC) to better understand the anatomical localization and communication patterns of the FRN. We show that the FRN is evident in both low- and high-frequency local field potentials (LFPs) recorded on electrocorticography. The FRN is larger in medial compared with lateral PFC, and coupling between theta band phase and high-frequency LFP power is also greater in medial PFC. Using Granger causality and conditional mutual information analyses, we provide evidence that feedback-related information propagates from medial to lateral PFC, and that this information transfer oscillates with theta-range periodicity. These results provide evidence for the dACC as the cortical source of the FRN, provide insight into the local computation of frontal midline theta, and have implications for reinforcement learning models of cognitive control.

  2. Simultaneous Analysis of SEPT9 Promoter Methylation Status, Micronuclei Frequency, and Folate-Related Gene Polymorphisms: The Potential for a Novel Blood-Based Colorectal Cancer Biomarker

    Directory of Open Access Journals (Sweden)

    Gloria Ravegnini

    2015-12-01

    Full Text Available One challenge in colorectal cancer (CRC is identifying novel biomarkers to be introduced in screening programs. The present study investigated the promoter methylation status of the SEPT9 gene in peripheral blood samples of subjects’ positive fecal occult blood test (FOBT. In order to add new insights, we investigated the association between SEPT9 promoter methylation and micronuclei frequency, and polymorphisms in the folate-related pathway genes. SEPT9 promoter methylation, micronuclei frequency, and genotypes were evaluated on 74 individuals’ FOBT positive. Individuals were subjected to a colonoscopy that provided written informed consent for study participation. SEPT9 promoter methylation status was significantly lower in the CRC group than controls (p = 0.0006. In contrast, the CaCo2 cell-line, analyzed as a tissue specific model of colon adenocarcinoma, showed a significantly higher percentage of SEPT9 promoter methylation compared to the CRC group (p < 0.0001. Linear regression analysis showed an inverse correlation between micronuclei frequency and the decrease in the methylation levels of SEPT9 promoter region among CRC patients (β = −0.926, p = 0.0001. With regard to genotype analysis, we showed the involvement of the DHFR polymorphism (rs70991108 in SEPT9 promoter methylation level in CRC patients only. In particular, the presence of at least one 19 bp del allele significantly correlates with decreased SEPT9 promoter methylation, compared to the 19 bp ins/ins genotype (p = 0.007. While remaining aware of the strengths and limitations of the study, this represents the first evidence of a novel approach for the early detection of CRC, using SEPT9 promoter methylation, micronuclei frequency and genotypes, with the potential to improve CRC risk assessment.

  3. Simultaneous Analysis of SEPT9 Promoter Methylation Status, Micronuclei Frequency, and Folate-Related Gene Polymorphisms: The Potential for a Novel Blood-Based Colorectal Cancer Biomarker.

    Science.gov (United States)

    Ravegnini, Gloria; Zolezzi Moraga, Juan Manuel; Maffei, Francesca; Musti, Muriel; Zenesini, Corrado; Simeon, Vittorio; Sammarini, Giulia; Festi, Davide; Hrelia, Patrizia; Angelini, Sabrina

    2015-12-01

    One challenge in colorectal cancer (CRC) is identifying novel biomarkers to be introduced in screening programs. The present study investigated the promoter methylation status of the SEPT9 gene in peripheral blood samples of subjects' positive fecal occult blood test (FOBT). In order to add new insights, we investigated the association between SEPT9 promoter methylation and micronuclei frequency, and polymorphisms in the folate-related pathway genes. SEPT9 promoter methylation, micronuclei frequency, and genotypes were evaluated on 74 individuals' FOBT positive. Individuals were subjected to a colonoscopy that provided written informed consent for study participation. SEPT9 promoter methylation status was significantly lower in the CRC group than controls (p = 0.0006). In contrast, the CaCo2 cell-line, analyzed as a tissue specific model of colon adenocarcinoma, showed a significantly higher percentage of SEPT9 promoter methylation compared to the CRC group (p < 0.0001). Linear regression analysis showed an inverse correlation between micronuclei frequency and the decrease in the methylation levels of SEPT9 promoter region among CRC patients (β = -0.926, p = 0.0001). With regard to genotype analysis, we showed the involvement of the DHFR polymorphism (rs70991108) in SEPT9 promoter methylation level in CRC patients only. In particular, the presence of at least one 19 bp del allele significantly correlates with decreased SEPT9 promoter methylation, compared to the 19 bp ins/ins genotype (p = 0.007). While remaining aware of the strengths and limitations of the study, this represents the first evidence of a novel approach for the early detection of CRC, using SEPT9 promoter methylation, micronuclei frequency and genotypes, with the potential to improve CRC risk assessment.

  4. Transcriptional Wiring of Cell Wall-Related Genes in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Marek Mutwil; Colin Ruprecht; Federico M. Giorgi; Martin Bringmann; Bj(o)rn Usadel; Staffan Persson

    2009-01-01

    Transcriptional coordination, or co-expression, of genes may signify functional relatedness of the correspond-ing proteins. For example, several genes involved in secondary cell wall cellulose biosynthesis are co-expressed with genes engaged in the synthesis of xylan, which is a major component of the secondary cell wall. To extend these types of anal-yses, we investigated the co-expression relationships of all Carbohydrate-Active enZYmes (CAZy)-related genes for Arabidopsis thaliana. Thus, the intention was to transcriptionally link different cell wall-related processes to each other, and also to other biological functions. To facilitate easy manual inspection, we have displayed these interactions as networks and matrices, and created a web-based interface (http://aranet.mpimp-golm.mpg.de/corecarb) containing downloadable files for all the transcriptional associations.

  5. T cells and macrophages in Trypanosoma brucei-related glomerulopathy.

    Science.gov (United States)

    van Velthuysen, M L; Mayen, A E; van Rooijen, N; Fleuren, G J; de Heer, E; Bruijn, J A

    1994-08-01

    In a previous study, susceptibility for Trypanosoma brucei-related glomerulopathy in mice was shown to be dependent on non-major histocompatibility complex genes. Glomerular disease in this model could not be explained by the production of autoantibodies alone. In order to analyze which part of the defense system, in addition to the B-cell compartment, is involved in the development of this infection-related glomerular disease, groups of athymic (BALB/c rnu/rnu), splenectomized, or macrophage-depleted BALB/c mice were inoculated with T. brucei parasites. Polyclonal B-cell activation, invariably observed in infected BALB/c mice, was absent in BALB/c rnu/rnu mice. Glomerular disease in athymic mice, however, as defined by albuminuria and deposition of immune complexes, was not different from that seen in euthymic infected BALB/c mice. Splenectomy prior to inoculation of parasites led to a decreased incidence of albuminuria in 40% of the animals, whereas splenectomy 21 days after inoculation reduced albuminuria significantly, suggesting a role for spleen cells in the induction of glomerular disease. After macrophage depletion with liposome-encapsulated dichlorodimethylene-diphosphonate, infected BALB/c mice developed significantly higher albuminuria levels for a period up to 2 weeks after depletion. Therefore, it was concluded that the development of T. brucei-related glomerular disease is independent of thymus-matured T cells, while the involvement of macrophages in the development of proteinuria is inhibitory rather than disease inducing. Spleen cells other than thymus-dependent T cells, B cells, and macrophages should be investigated for their role in the pathogenesis of this glomerulopathy. PMID:7913696

  6. Glycoconjugates and Related Molecules in Human Vascular Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Norihiko Sasaki

    2013-01-01

    Full Text Available Vascular endothelial cells (ECs form the inner lining of blood vessels. They are critically involved in many physiological functions, including control of vasomotor tone, blood cell trafficking, hemostatic balance, permeability, proliferation, survival, and immunity. It is considered that impairment of EC functions leads to the development of vascular diseases. The carbohydrate antigens carried by glycoconjugates (e.g., glycoproteins, glycosphingolipids, and proteoglycans mainly present on the cell surface serve not only as marker molecules but also as functional molecules. Recent studies have revealed that the carbohydrate composition of the EC surface is critical for these cells to perform their physiological functions. In this paper, we consider the expression and functional roles of endogenous glycoconjugates and related molecules (galectins and glycan-degrading enzymes in human ECs.

  7. Lonidamine Causes Inhibition of Angiogenesis-Related Endothelial Cell Functions

    Directory of Open Access Journals (Sweden)

    Donatella Del Bufalo

    2004-09-01

    Full Text Available The aim of this study was to assess whether lonidamine (LND interferes with some steps in angiogenesis progression. We report here, for the first time, that LND inhibited angiogenic-related endothelial cell functions in a dose-dependent manner (1-50 μg/ml. In particular, LND decreased proliferation, migration, invasion, and morphogenesis on matrigel of different endothelial cell lines. Zymographic and Western blot analysis assays showed that LND treatment produced a reduction in the secretion of matrix metalloproteinase-2 and metalloproteinase-9 by endothelial cells. Vessel formation in a matrigel plug was also reduced by LND. The viability, migration, invasion, and matrix metalloproteinase production of different tumor cell lines were not affected by low doses of LND (1-10 μg/ml, whereas 50 μg/ml LND, which corresponds to the dose used in clinical management of tumors, triggered apoptosis both in endothelial and tumor cells. Together, these data demonstrate that LND is a compound that interferes with endothelial cell functions, both at low and high doses. Thus, the effect of LND on endothelial cell functions, previously undescribed, may be a significant contributor to the antitumor effect of LND observed for clinical management of solid tumors.

  8. The annual frequency of root fillings, tooth extractions and pulp-related procedures in Danish adults during 1977-2003

    DEFF Research Database (Denmark)

    Bjørndal, L.; Reit, C.

    2004-01-01

    endodontic epidemiology, frequency of root fillings, pulp capping, stepwise excavation, tooth extractions......endodontic epidemiology, frequency of root fillings, pulp capping, stepwise excavation, tooth extractions...

  9. High frequency of the CCR5delta32 variant among individuals from an admixed Brazilian population with sickle cell anemia

    Directory of Open Access Journals (Sweden)

    J.A.B. Chies

    2003-01-01

    Full Text Available Homozygous sickle cell disease (SCD has a wide spectrum of clinical manifestations. In Brazil, the main cause of death of individuals with SCD is recurrent infection. The CCR5delta32 allele, which confers relative resistance to macrophage-tropic HIV virus infection, probably has reached its frequency and world distribution due to other pathogens that target macrophage in European populations. In the present investigation a relatively higher prevalence (5.1% of the CCR5delta32 allele was identified, by PCR amplification using specific primers, in 79 SCD patients when compared to healthy controls (1.3% with the same ethnic background (Afro-Brazilians. Based on a hypothesis that considers SCD as a chronic inflammatory condition, and since the CCR5 chemokine receptor is involved in directing a Th1-type immune response, we suggest that a Th1/Th2 balance can influence the morbidity of SCD. If the presence of the null CCR5delta32 allele results in a reduction of the chronic inflammation state present in SCD patients, this could lead to differential survival of SCD individuals who are carriers of the CCR5delta32 allele. This differential survival could be due to the development of less severe infections and consequently reduced or less severe vaso-occlusive crises.

  10. Relative frequencies of supernovae types: dependence on host galaxy magnitude, galactocentric radius and local metallicity

    CERN Document Server

    Boissier, S

    2009-01-01

    Context: Stellar evolution theory suggests that the relationship between number ratios of supernova (SN) types and metallicity holds important clues as to the nature of the progenitor stars (mass, metallicity, rotation, binarity, etc). Aims: We investigate the metallicity dependence of number ratios of various SN types, using a large sample of SN along with information on their radial position in, and magnitude of, their host galaxy. Methods: We derive typical galaxian metallicities (using the well known metallicity-luminosity relation) and local metallicities, i.e. at the position of the SN; in the latter case, we use the empirical fact that the metallicity gradients in disk galaxies are ~ constant when expressed in dex/R25. Results: We confirm a dependence of the N(Ibc)/N(II) ratio on metallicity; recent single star models with rotation and binary star models with no rotation appear to reproduce equally well that metallicity dependence. The size of our sample does not allow significant conclusions on the N(...

  11. Frequency of p53 Gene Mutation and Protein Expression in Oral Squamous Cell Carcinoma

    International Nuclear Information System (INIS)

    Objective: To determine the frequency of p53 gene mutation and protein expression in Oral Squamous Cell Carcinoma (OSCC) and to establish correlation between the two. Study Design: Analytical study. Place and Duration of Study: Histopathology Department and Molecular Biology Laboratory, Armed Forces Institute of Pathology (AFIP), Rawalpindi, from May 2010 to May 2011. Methodology: Thirty diagnosed cases of OSCC were selected by consecutive sampling. Seventeen were retrieved from the record files of the AFIP, and 13 fresh/frozen sections were selected from patients reporting to the Oral Surgery Department, Armed Forces Institute of Dentistry (AFID). Gene p53 mutation was analyzed in all the cases using PCRSSCP analysis. DNA was extracted from the formalin-fixed and paraffin-embedded tissue sections and fresh/frozen sections. DNA thus extracted was amplified by polymerase chain reaction. The amplified products were denatured and finally analyzed by gel electrophoresis. Gene mutation was detected as electrophoretic mobility shift. The immunohistochemical marker p53 was applied to the same 30 cases and overexpression of protein p53 was recorded. Results: Immunohistochemical expression of marker p53 was positive in 67% (95% Confidence Interval (CI) 48.7 - 80.9) of the cases. Mutations of the p53 gene were detected in 23% (95% CI 11.5 - 41.2) of the OSCC. No statistically significant correlation was found between p53 gene mutation and protein p53 expression (rs = - 0.057, p = 0.765). Conclusion: A substantial number of patients have p53 gene mutation (23%) and protein p53 expression (67%) in oral squamous cell carcinoma (OSCC). (author)

  12. Frequency of red cell, leukocytic and platelet alloantibodies in patients with hematological diseases

    Directory of Open Access Journals (Sweden)

    N. V. Mineeva

    2014-07-01

    Full Text Available History of multiple transfusions in patients with hematological diseases increases the likelihood of immunization to donor blood cells antigensand immunological complications development. Incidence of alloantibodies development in this patients was assessed in this work. Alloantibodies detection was performed in patients with aplastic anemia, acute leukemia, chronic lymphocytic leukemia, and autoimmune thrombocytopenia. 9696 patients were included in this study. Frequency of alloantibodies to red cell antigens was 3.8 %, with 0.9 % of the antibody belong to the immunoglobulin G, and 2.9 % of the cases – to immunoglobulin M. Most of the IgG antibodies had following specificity:monospecific anti-D antibody (21 cases, anti-DC and anti-DE antibodies (4 cases, anti-C (8 cases, anti-E (15, anti-c (13, and anti-K (11. Anti-e (1, anti-Fya (2, anti-Lea (4, anti-S (2, anti-s (2, anti-Jka (2 antibodies were less common. Granulocytes antibodies were found in 66.7 % of 384 patients, with results dependent on the detection method used. The presence of antiplatelet alloantibodies studied in 285 serum samples, of which antibodies were detected in 99 patients (34.7 %. Specificity of platelet antibodies was determined in three serum samples only: anti-2b, anti-1a, anti-1b. In other patients, probably present antibodies to several antigens simultaneously, and to identify them was not possible.

  13. Reduced relative frequency of knowledge of results without visual feedback in learning a golf-putting task.

    Science.gov (United States)

    Ishikura, Tadao

    2008-02-01

    This study examined the effects of reduced relative frequency of knowledge of results (KR) on learning to putt in golf. Participants (19 men and 15 women) putted a golf ball, stopping the ball on a line at a distance of 3.5 m from the starting position, which included an uphill portion. After a pretest, participants were assigned as they arrived in balanced order by sex to one of two groups (100% KR, 33% KR) and practiced 60 trials. Those in the 100% KR group performed the task in its natural context, while others assigned to the 33% KR were shown the location of the putted ball after every third trial. All participants then performed a posttest and two retention tests, done 10 min. and 24 hr. after the posttest. Analysis at posttest showed each group had a constant error and an absolute constant error (/CE/) less than those at pretest. Also, in the retention test conducted the following day, the constant error of the 33% KR group was less than that of the 100% KR group. Third, in the posttest and both retention tests, the /CE/ of the 100% KR group was larger than that of the 33% KR group. These results suggest that reduced relative frequency of knowledge of results is effective in learning the accuracy of the golf putt. PMID:18459371

  14. Radio Frequency Magnetron Sputtering Deposition of TiO2 Thin Films and Their Perovskite Solar Cell Applications

    OpenAIRE

    Cong Chen; Yu Cheng; Qilin Dai; Hongwei Song

    2015-01-01

    In this work, we report a physical deposition based, compact (cp) layer synthesis for planar heterojunction perovskite solar cells. Typical solution-based synthesis of cp layer for perovskite solar cells involves low-quality of thin films, high-temperature annealing, non-flexible devices, limitation of large-scale production and that the effects of the cp layer on carrier transport have not been fully understood. In this research, using radio frequency magnetron sputtering (RFMS), TiO2 cp lay...

  15. Relation between the shape of high frequency heating coil and the temperature distribution in specimen during thermal fatigue test

    International Nuclear Information System (INIS)

    The high frequency heating apparatus used for thermal fatigue tests, the relation between the shape of heating coils, and the temperature distribution of specimens was experimentally examined for SUS 304 stainless steel. Relations between heating coil dimensions and heating rate, the most ideal coil shape for various specimen types, and the effects of temperature range and specimen shape on temperature distribution are described. Results show that the heating rate increases with decreasing distance from specimen surface to heating coil and with increasing coil tube diameter. For the general cylindrical and hour glass type specimens, the most ideal coil shapes are a separate type and a parallel type coil, respectively, as judged from the point of temperature distribution. (U.S.)

  16. Influence of substrate concentration and feed frequency on ammonia inhibition in microbial fuel cells

    Science.gov (United States)

    Tice, Ryan C.; Kim, Younggy

    2014-12-01

    Excessive amounts of ammonia are known to inhibit exoelectrogenic activities in microbial fuel cells (MFCs). However, the threshold ammonia concentration that triggers toxic effects is not consistent among literature papers, indicating that ammonia inhibition can be affected by other operational factors. Here, we examined the effect of substrate concentration and feed frequency on the capacity of exoelectrogenic bacteria to resist against ammonia inhibition. The high substrate condition (2 g L-1 sodium acetate, 2-day feed) maintained high electricity generation (between 1.1 and 1.9 W m-2) for total ammonia concentration up to 4000 mg-N L-1. The less frequent feed condition (2 g L-1 sodium acetate, 6-day feed) and the low substrate condition (0.67 g L-1 sodium acetate, 2-day feed) resulted in substantial decreases in electricity generation at total ammonia concentration of 2500 and 3000 mg-N L-1, respectively. It was determined that the power density curve serves as a better indicator than continuously monitored electric current for predicting ammonia inhibition in MFCs. The chemical oxygen demand (COD) removal gradually decreased at high ammonia concentration even without ammonia inhibition in electricity generation. The experimental results demonstrated that high substrate concentration and frequent feed substantially enhance the capacity of exoelectrogenic bacteria to resist against ammonia inhibition.

  17. Limiting-dilution analysis for the determination of leukemic cell frequencies after bone marrow decontamination with mafosfamide or merocyanine 540

    Energy Technology Data Exchange (ETDEWEB)

    Porcellini, A.; Talevi, N.; Marchetti-Rossi, M.T.; Palazzi, M.; Manna, A.; Sparaventi, G.; Delfini, C.; Valentini, M.

    1987-11-01

    To stimulate a leukemia remission marrow, cell suspensions of normal human bone marrow were mixed with human acute lymphoblastic or myelogenous leukemic cells of the CCRF-SF, Nalm-6, and K-562 lines. The cell mixtures were incubated in vitro with mafosfamide (AZ) or with the photoreactive dye merocyanine 540 (MC-540). A quantity of 10(4) cells of the treated suspensions was dispensed into microculture plates, and graded cell numbers of the line used to contaminate the normal marrow were added. Limiting-dilution analysis was used to estimate the frequency of leukemia cells persisting after treatment with the decontaminating agents. Treatment with AZ or MC-540 produced a total elimination (ie, 6 logs or 5.3 logs respectively) of B cell acute leukemia cells (CCRF-SB), whereas nearly 1.7 logs and 2 logs of K-562 acute myelogenous blasts were still present in the cell mixtures after treatment with MC-540 and AZ, respectively. Treatment of the Nalm-6-contaminated cell mixtures with AZ resulted in 100% elimination of clonogenic cells, whereas nearly 80% decontamination was obtained with MC-540. Our results suggest that treatment with AZ could be an effective method of eliminating clonogenic tumor cells from human bone marrow. MC-540, shown by previous studies to spare sufficient pluripotential stem cells to ensure hemopoietic reconstitution in the murine model and in clinical application, has comparable effects and merits trials for possible clinical use in autologous bone marrow transplantation.

  18. A correlative study on the frequencies of radiation-induced chromosome aberrations in somatic and germ cells of mammals

    International Nuclear Information System (INIS)

    A series of investigations on the correlation between the frequencies of radiation-induced chromosome aberrations in somatic and germ cells of mouse and rhesus monkey is described. In the mouse the induction of reciprocal translocations in bone-marrow cells was compared with that in spermatogonia (as scored in the descending spermatocytes). In the rhesus monkey frequencies of radiation-induced chromosome aberrations in spermatogonia and peripheral blood lymphocytes were studied. Furthermore the effect of multigeneration irradiation (69 generations with 200 rads X-rays) on the sensitivity for translocation induction in spermatogonia of male mice was studied. Frequencies of dicentric chromosomes and chromosomal deletions in cultured peripheral blood lymphocytes of 5 different types of mice were determined following in vitro irradiation with doses of 100 and/or 200 rad X-rays. To obtain more insight into the processes underlying translocation induction in spermatogonia of the mouse, fractionation experiments were conducted

  19. An increased frequency of autoantibody-inducing CD4+ T cells in pre-diseased lupus-prone mice.

    Science.gov (United States)

    Busser, Brian W; Cancro, Michael P; Laufer, Terri M

    2004-07-01

    Pathogenic autoantibody production in murine models of lupus is dependent on autoreactive CD4+ helper T cells. However, the mechanisms which permit the selection and maintenance of this autoantibody-inducing CD4+ T-cell repertoire are currently unknown. We hypothesized that the peripheral CD4+ T-cell repertoire of lupus-prone mice was enriched with autoantibody-inducing specificities. To test this, we utilized the splenic focus assay to determine if pre-diseased lupus-prone (NZB x NZW)F(1) mice have an elevated frequency of autoreactive CD4+ T lymphocytes capable of supporting autoantibody production. The splenic focus limiting dilution assay permits anti-nuclear antibodies to be generated from contact-dependent T-B interactions in vitro. We show that young, pre-diseased lupus-prone mice have an elevated frequency of autoantibody-inducing CD4+ T cells. Interestingly, these autoantibody-inducing CD4+ T-cell responses are also present in the thymus. Therefore, an elevated frequency of autoantibody-inducing CD4+ T cells predisposes lupus-prone mice to the development of autoantibodies.

  20. Decreased frequencies of circulating follicular helper T cell counterparts and plasmablasts in ankylosing spondylitis patients Naive for TNF blockers.

    Directory of Open Access Journals (Sweden)

    María-Belén Bautista-Caro

    Full Text Available Follicular helper T cells (Tfh, localized in lymphoid organs, promote B cell differentiation and function. Circulating CD4 T cells expressing CXCR5, ICOS and/or PD-1 are counterparts of Tfh. Three subpopulations of circulating CD4+CXCR5+ cells have been described: CXCR3+CCR6- (Tfh-Th1, CXCR3-CCR6+ (Tfh-Th17, and CXCR3-CCR6- (Tfh-Th2. Only Tfh-Th17 and Tfh-Th2 function as B cell helpers. Our objective was to study the frequencies of circulating Tfh (cTfh, cTfh subsets and plasmablasts (CD19+CD20-CD27+CD38high cells, and the function of cTfh cells, in patients with Ankylosing Spondylitis (AS. To this end, peripheral blood was drawn from healthy controls (HC (n = 50, AS patients naïve for TNF blockers (AS/nb (n = 25 and AS patients treated with TNF blockers (AS/b (n = 25. The frequencies of cTfh and plasmablasts were determined by flow cytometry. Cocultures of magnetically sorted CD4+CXCR5+ T cells with autologous CD19+CD27- naïve B cells were established from 3 AS/nb patients and 3 HC, and concentrations of IgG, A and M were measured in supernatants. We obseved that AS/nb but not AS/b patients, demonstrated decreased frequencies of circulating CD4+CXCR5+ICOS+PD-1+ cells and plasmablasts, together with a decreased (Tfh-Th17+Tfh-Th2/Tfh-Th1 ratio. The amounts of IgG and IgA produced in cocultures of CD4+CXCR5+ T cells with CD19+CD27- B cells of AS/nb patients were significantly lower than observed in cocultures established from HC. In summary, AS/nb but not AS/b patients, demonstrate a decreased frequency of cTfh and plasmablasts, and an underrepresentation of cTfh subsets bearing a B helper phenotype. In addition, peripheral blood CD4+CXCR5+ T cells of AS/nb patients showed a decreased capacity to help B cells ex vivo.

  1. Compact cascadable gm-C all-pass true time delay cell with reduced delay variation over frequency

    NARCIS (Netherlands)

    Garakoui, Seyed Kasra; Klumperink, Eric A.M.; Nauta, Bram; Vliet, van Frank E.

    2015-01-01

    At low-GHz frequencies, analog time-delay cells realized by LC delay lines or transmission lines are unpractical in CMOS, due to their large size. As an alternative, delays can be approximated by all-pass filters exploiting transconductors and capacitors (g m -C filters). This paper presents an easi

  2. Frequency-dependent reduction of voltage-gated sodium current modulates retinal ganglion cell response rate to electrical stimulation

    Science.gov (United States)

    Tsai, David; Morley, John W.; Suaning, Gregg J.; Lovell, Nigel H.

    2011-10-01

    The ability to elicit visual percepts through electrical stimulation of the retina has prompted numerous investigations examining the feasibility of restoring sight to the blind with retinal implants. The therapeutic efficacy of these devices will be strongly influenced by their ability to elicit neural responses that approximate those of normal vision. Retinal ganglion cells (RGCs) can fire spikes at frequencies greater than 200 Hz when driven by light. However, several studies using isolated retinas have found a decline in RGC spiking response rate when these cells were stimulated at greater than 50 Hz. It is possible that the mechanism responsible for this decline also contributes to the frequency-dependent 'fading' of electrically evoked percepts recently reported in human patients. Using whole-cell patch clamp recordings of rabbit RGCs, we investigated the causes for the spiking response depression during direct subretinal stimulation of these cells at 50-200 Hz. The response depression was not caused by inhibition arising from the retinal network but, instead, by a stimulus-frequency-dependent decline of RGC voltage-gated sodium current. Under identical experimental conditions, however, RGCs were able to spike at high frequency when driven by light stimuli and intracellular depolarization. Based on these observations, we demonstrated a technique to prevent the spiking response depression.

  3. Transplantation of retinal pigment epithelial cells - a possible future treatment for age-related macular degeneration

    DEFF Research Database (Denmark)

    Wiencke, Anne Katrine

    2001-01-01

    ophthalmology, age-related macular degeneration, retinal pigment epithelial cells, transplantation, treatment......ophthalmology, age-related macular degeneration, retinal pigment epithelial cells, transplantation, treatment...

  4. Transplantation of retinal pigment epithelial cells - a possible future treatment for age-related macular degeneration

    DEFF Research Database (Denmark)

    Wiencke, Anne Katrine

    2001-01-01

    ophthalmology, age-related macular degeneration, transplantation, retinal pigment epithelial cells, treatment......ophthalmology, age-related macular degeneration, transplantation, retinal pigment epithelial cells, treatment...

  5. Increased frequencies of Th22 cells as well as Th17 cells in the peripheral blood of patients with ankylosing spondylitis and rheumatoid arthritis.

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    Full Text Available BACKGROUND: T-helper (Th 22 is involved in the pathogenesis of inflammatory diseases. The roles of Th22 cells in the pathophysiological of ankylosing spondylitis (AS and rheumatoid arthritis (RA remain unsettled. So we examined the frequencies of Th22 cells, Th17 cells and Th1 cells in peripheral blood (PB from patients with AS and patients with RA compared with both healthy controls as well as patients with osteoarthritis. DESIGN AND METHODS: We studied 32 AS patients, 20 RA patients, 10 OA patients and 20 healthy controls. The expression of IL-22, IL-17 and IFN-γ were examined in AS, RA, OA patients and healthy controls by flow cytometry. Plasma IL-22 and IL-17 levels were examined by enzyme-linked immunosorbent assay. RESULTS: Th22 cells, Th17 cells and interleukin-22 were significantly elevated in AS and RA patients compared with OA patients and healthy controls. Moreover, Th22 cells showed positive correlation with Th17 cells as well as interleukin-22 in AS and RA patients. However, positive correlation between IL-22 and Th17 cells was only found in AS patients not in RA patients. In addition, the percentages of both Th22 cells and Th17 cells correlated positively with disease activity only in RA patients not in AS patients. CONCLUSIONS: The frequencies of both Th22 cells and Th17 cells were elevated in PB from patients with AS and patients with RA. These findings suggest that Th22 cells and Th17 cells may be implicated in the pathogenesis of AS and RA, and Th22 cells and Th17 cells may be reasonable cellular targets for therapeutic intervention.

  6. Multi-micronucleus cells related with viral diseases, detected in the study of children affected by the Chernobyl accident

    International Nuclear Information System (INIS)

    Cells with multiple chromosome aberrations have been observed in human peripheral blood lymphocytes. Different explanation have proposed, included hot particle induction in persons related to the Chernobyl accident. The frequency of chromosome aberration and micronuclei were established in 14 Ukrainian children with different hematological disorders. They arrived in Cuba thanks to the program by means of which medical attention is offered to children from areas affected by the Chernobyl accident. At least 500 metaphases and bi-nucleate cells were analyzed in each case. The detection of 4 cells with 7-11 micronuclei in a 14 year old boy with cat scratch disease was the most significant cytogenetical finding. The viral origin of the cat scratch disease has been reported, this suggested a viral etiology of the cells with multiple micronuclei. No rogue cells were detected. Cells with multiple micronuclei or rogue cells were not found in other patients from this group. (authors). 7 refs., 3 tabs

  7. Cell Cycle Related Differentiation of Bone Marrow Cells into Lung Cells

    Energy Technology Data Exchange (ETDEWEB)

    Dooner, Mark; Aliotta, Jason M.; Pimental, Jeffrey; Dooner, Gerri J.; Abedi, Mehrdad; Colvin, Gerald; Liu, Qin; Weier, Heinz-Ulli; Dooner, Mark S.; Quesenberry, Peter J.

    2007-12-31

    Green-fluorescent protein (GFP) labeled marrow cells transplanted into lethally irradiated mice can be detected in the lungs of transplanted mice and have been shown to express lung specific proteins while lacking the expression of hematopoietic markers. We have studied marrow cells induced to transit cell cycle by exposure to IL-3, IL-6, IL-11 and steel factor at different times of culture corresponding to different phases of cell cycle. We have found that marrow cells at the G1/S interface have a 3-fold increase in cells which assume a lung phenotype and that this increase is no longer seen in late S/G2. These cells have been characterized as GFP{sup +} CD45{sup -} and GFP{sup +} cytokeratin{sup +}. Thus marrow cells with the capacity to convert into cells with a lung phenotype after transplantation show a reversible increase with cytokine induced cell cycle transit. Previous studies have shown the phenotype of bone marrow stem cells fluctuates reversibly as these cells traverse cell cycle, leading to a continuum model of stem cell regulation. The present studies indicate that marrow stem cell production of nonhematopoietic cells also fluctuates on a continuum.

  8. A study of the endocervical columnar cells I - morphology and frequency

    Directory of Open Access Journals (Sweden)

    Eitel Duarte

    1966-01-01

    Full Text Available After the observation of many thousands of histological sections of the endocervical mucosa it became evident that its columnar cells present a great variety of aspects not only those of the surface of the canal but also those of the glands. A classification of these cells was made taking into account the staining affinity, the intensity staining of the cytoplasm, the presence or absence of cilia, the shape and location of the nucleus. The various combinations of these different data made possible the characterization of 26 types of cells which we labelled by the alphabetical letters. Two hundred and fifty cervices obtained by cervical amputation and by hysterectomy were studied. The uteri presented lesions in the course of routine laboratory examination. In each of the 250 histological sections there were specifically counted 2,000 columnar cells which cover the cervical canal and 2,000columnar cells which form the glands. A graphic representation of the frequency of both the superficial and glandular columnar cells was presented; this was given the name EPITHELIOGRAM. The variation of the cellular "composition" of each epithelium is discussed and the frequency of the various cellular types after the count of one million of cells is presented.O estudo minucioso do epitélio da mucosa endocervical possibilitou o reconhecimento de vinte e seis tipos de células cilíndricas, tanto na superfície de revestimento do canal, como nas chamadas glândulas endocervicais. Para a classificação destas 26 células, que tomaram, cada uma, uma letra do alfabeto, foram levados em consideração a intensidade de coloração, a apresença ou não de cílios, a forma e dimensões dos núcleos e sua posição na célula. Foram analisados inicialmente 250 cortes histológicos, sendo contadas especìficamente, em cada corte, 2000 células cilíndricas de revestimento e 2000 células cilíndricas das glândulas. Em cada caso foram anotados, nas tabelas, além dos

  9. Measurement of relative permeability of fuel cell diffusion media

    KAUST Repository

    Hussaini, I.S.

    2010-06-01

    Gas diffusion layer (GDL) in PEM fuel cells plays a pivotal role in water management. Modeling of liquid water transport through the GDL relies on knowledge of relative permeability functions in the in-plane and through-plane directions. In the present work, air and water relative permeabilities are experimentally determined as functions of saturation for typical GDL materials such as Toray-060, -090, -120 carbon paper and E-Tek carbon cloth materials in their plain, untreated forms. Saturation is measured using an ex situ gravimetric method. Absolute and relative permeability functions in the two directions of interest are presented and new correlations for in-plane relative permeability of water and air are established. © 2010 Elsevier B.V. All rights reserved.

  10. The impact of sodium citrate on dialysis catheter function and frequency of catheter-related bacteriemia and haemorrhage

    Directory of Open Access Journals (Sweden)

    Maciej Szymczak

    2009-10-01

    Full Text Available Vascular access is one of the most important problems of hemodialysis therapy. It is known that an arteriovenous fi sutla provides the best vascular access, but its creation is not always possible. Other solutions, such as the insertion of a central venous catheter, are then required. Adequate protection of such catheters by interdialytic fi ll with locking solution affects the frequency of hemodialysis-related complications. The most widespread catheter locking solution is heparin. Sodium citrate is being used more frequent recently. Available data indicate that hemorrhage is 11.9 times more frequent if the catheter locking solution is 5000 IU/ml heparin than if 4�0sodium citrate or 1000 IU/ml heparin is used. Other data indicate that the frequency of infection is statistically decreased when 30�0sodium citrate is used to fi ll the catheter instead of 5000 IU/ml heparin. Analogous data on 46.7�0sodium citrate are not consistent. It seems that the use of 4�0sodium citrate instead of 5000 IU/ml heparin does not decrease the frequency of infections. Numerous studies indicate that sodium citrate at various concentrations exerts a positive infl lence on catheter function. However, not all data are in accord. The spill of sodium citrate from the catheter to the systemic circulation is connected with a risk of adverse events. It may be dangerous if the citrate concentration is 46.7�20However, adequate fi lling of the catheter should prezent such events. Available data indicate that fi lling of the catheter with a solution of citrate of a concentration of no more than 30�0should be safe. Data on 46.7�0citrate are not conclusive, so precautions should be taken.

  11. Intrinsically photosensitive retinal ganglion cell function in relation to age

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Lund-Andersen, Henrik;

    2012-01-01

    The activity of melanopsin containing intrinsically photosensitive ganglion retinal cells (ipRGC) can be assessed by a means of pupil responses to bright blue (appr.480 nm) light. Due to age related factors in the eye, particularly, structural changes of the lens, less light reaches retina. The aim...... of this study was to examine how age and in vivo measured lens transmission of blue light might affect pupil light responses, in particular, mediated by the ipRGC....

  12. Robust low frequency current ripple elimination algorithm for grid-connected fuel cell systems with power balancing technique

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Soo; Choe, Gyu-Yeong; Lee, Byoung-Kuk [School of Information and Communication Engineering, Sungkyunkwan University, 300 Cheoncheon-dong, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Kang, Hyun-Soo [R and D Center, Advanced Drive Technology (ADT) Company, 689-26 Geumjeong-dong, Gunpo-si, Gyeonggi-do 435-862 (Korea, Republic of)

    2011-05-15

    The low frequency current ripple in grid-connected fuel cell systems is generated from dc-ac inverter operation, which generates 60 Hz fundamental component, and gives harmful effects on fuel cell stack itself, such as making cathode surface responses slower, causing an increase of more than 10% in the fuel consumption, creating oxygen starvation, causing a reduction in the operating lifetime, and incurring a nuisance tripping such as overload situation. With these reasons, low frequency current ripple makes fuel cell system unstable and lifetime of fuel cell stack itself short. This paper presents a fast and robust control algorithm to eliminate low frequency current ripple in grid-connected fuel cell systems. Compared with the conventional methods, in the proposed control algorithm, dc link voltage controller is shifted from dc-dc converter to dc-ac inverter, resulting that dc-ac inverter handles dc link voltage control and output current control simultaneously with help of power balancing technique. The results indicate that the proposed algorithm can not only completely eliminate current ripple but also significantly reduce the overshoot or undershoot during transient states without any extra hardware. The validity of the proposed algorithm is verified by computer simulations and also by experiments with a 1 kW laboratory prototype. (author)

  13. Polyamines in relation to growth in carrot cell cultures.

    Science.gov (United States)

    Fallon, K M; Phillips, R

    1988-09-01

    Changes in polyamine metabolism were investigated in relation to growth of cell suspension cultures of carrot (Daucus carota, cv Chantenay). Changes in levels of the major amines putrescine and spermidine throughout the culture period correlated poorly with changes in fresh weight, but a closer correlation with the minor component spermine was observed. The arginine decarboxylase (ADC) inhibitor difluoromethylarginine (DFMA) strongly and specifically inhibited ADC activity in the supernatant, reduced the major amine (putrescine) by 95% and the total amine content by 80%. It had no effect on cell number and stimulated fresh weight by over 25% through increased cell expansion. Spermine content, in contrast, increased with DFMA concentration in parallel with fresh weight increases. Difluoromethylornithine strongly inhibited ornithine decarboxylase activity in the pellet, but had little effect on either polyamine levels or culture growth. It was concluded that little evidence for a correlation between free polyamines and cell number in carrot cultures could be detected, but that a possible correlation between spermine content and cell expansion was observed.

  14. Polyamines in Relation to Growth in Carrot Cell Cultures 1

    Science.gov (United States)

    Fallon, Kevin M.; Phillips, Richard

    1988-01-01

    Changes in polyamine metabolism were investigated in relation to growth of cell suspension cultures of carrot (Daucus carota, cv Chantenay). Changes in levels of the major amines putrescine and spermidine throughout the culture period correlated poorly with changes in fresh weight, but a closer correlation with the minor component spermine was observed. The arginine decarboxylase (ADC) inhibitor difluoromethylarginine (DFMA) strongly and specifically inhibited ADC activity in the supernatant, reduced the major amine (putrescine) by 95% and the total amine content by 80%. It had no effect on cell number and stimulated fresh weight by over 25% through increased cell expansion. Spermine content, in contrast, increased with DFMA concentration in parallel with fresh weight increases. Difluoromethylornithine strongly inhibited ornithine decarboxylase activity in the pellet, but had little effect on either polyamine levels or culture growth. It was concluded that little evidence for a correlation between free polyamines and cell number in carrot cultures could be detected, but that a possible correlation between spermine content and cell expansion was observed. PMID:16666271

  15. Phagocytosis by glomerular endothelial cells in infection-related glomerulopathy.

    Science.gov (United States)

    van Velthuysen, M L; Mayen, A E; Prins, F A; de Heer, E; Bruijn, J A; Fleuren, G J

    1994-01-01

    Glomerulonephritis in BALB/c mice following infection with Trypanosoma brucei is characterized by albuminuria and glomerular deposition of immunoglobulins. Electron-dense deposits are present in the mesangium, as well as subendothelially and subepithelially along the glomerular capillary wall. In this study the nature of intracytoplasmic, electron-dense, round structures observed in glomerular endothelial cells was investigated by immunoelectron-microscopy and enzyme histochemistry. The presence of these structures was related in time with the development of proteinuria. Mice from the C57BL10 strain, which upon infection develop glomerular immune complexes without proteinuria, were examined as well. The results demonstrated that the first endothelial changes, occurring 3-4 weeks after infection, were swelling of endothelial cells containing intracytoplasmic, electron-dense, round structures. These changes were seen prior to the onset of proteinuria, and were not present in glomeruli of mice that did not develop proteinuria. The endothelial granules were shown to contain immunoglobulins and typical lysosomal enzymes, providing evidence for phagocytosis by the glomerular endothelial cells. Liver endothelial cells did not show comparable changes. Thus, local phagocytosis by glomerular endothelial cells is shown to be a specific event in the development of glomerular disease. PMID:7800204

  16. Evaluation of the Relative Validity of the Short Diet Questionnaire for Assessing Usual Consumption Frequencies of Selected Nutrients and Foods

    Directory of Open Access Journals (Sweden)

    Bryna Shatenstein

    2015-08-01

    Full Text Available A 36-item Short Diet Questionnaire (SDQ was developed to assess usual consumption frequencies of foods providing fats, fibre, calcium, vitamin D, in addition to fruits and vegetables. It was pretested among 30 community-dwelling participants from the Québec Longitudinal Study on Nutrition and Successful Aging, “NuAge” (n = 1793, 52.4% women, recruited in three age groups (70 ± 2 years; 75 ± 2 years; 80 ± 2 years. Following revision, the SDQ was administered to 527 NuAge participants (55% female, distributed among the three age groups, both sexes and languages (French, English prior to the second of three non-consecutive 24 h diet recalls (24HR and validated relative to the mean of three 24HR. Full data were available for 396 participants. Most SDQ nutrients and fruit and vegetable servings were lower than 24HR estimates (p < 0.05 except calcium, vitamin D, and saturated and trans fats. Spearman correlations between the SDQ and 24HR were modest and significant (p < 0.01, ranging from 0.19 (cholesterol to 0.45 (fruits and vegetables. Cross-classification into quartiles showed 33% of items were jointly classified into identical quartiles of the distribution, 73% into identical and contiguous quartiles, and only 7% were frankly misclassified. The SDQ is a reasonably accurate, rapid approach for ranking usual frequencies of selected nutrients and foods. Further testing is needed in a broader age range.

  17. Time-domain simulation of constitutive relations for nonlinear acoustics including relaxation for frequency power law attenuation media modeling

    Science.gov (United States)

    Jiménez, Noé; Camarena, Francisco; Redondo, Javier; Sánchez-Morcillo, Víctor; Konofagou, Elisa E.

    2015-10-01

    We report a numerical method for solving the constitutive relations of nonlinear acoustics, where multiple relaxation processes are included in a generalized formulation that allows the time-domain numerical solution by an explicit finite differences scheme. Thus, the proposed physical model overcomes the limitations of the one-way Khokhlov-Zabolotskaya-Kuznetsov (KZK) type models and, due to the Lagrangian density is implicitly included in the calculation, the proposed method also overcomes the limitations of Westervelt equation in complex configurations for medical ultrasound. In order to model frequency power law attenuation and dispersion, such as observed in biological media, the relaxation parameters are fitted to both exact frequency power law attenuation/dispersion media and also empirically measured attenuation of a variety of tissues that does not fit an exact power law. Finally, a computational technique based on artificial relaxation is included to correct the non-negligible numerical dispersion of the finite difference scheme, and, on the other hand, improve stability trough artificial attenuation when shock waves are present. This technique avoids the use of high-order finite-differences schemes leading to fast calculations. The present algorithm is especially suited for practical configuration where spatial discontinuities are present in the domain (e.g. axisymmetric domains or zero normal velocity boundary conditions in general). The accuracy of the method is discussed by comparing the proposed simulation solutions to one dimensional analytical and k-space numerical solutions.

  18. Multi-Objective Optimization of Vehicle Sound Package in Middle Frequency Using Gray Relational Analysis Coupled with Principal Component Analysis

    Science.gov (United States)

    Chen, Shuming; Wang, Dengfeng; Shi, Tianze; Chen, Jing

    2015-12-01

    This research studies optimization design of the thickness of sound packages for a passenger car. The major characteristics indexes for performance determined to evaluate the process are sound pressure level of the interior middle frequency noise and weight of the sound package. Three kinds of materials of sound packages are selected for the optimization process. The corresponding parameters of the sound packages are the thickness of the insulation plate for outer side of the firewall, thickness of the sound absorbing wool for inner side of the firewall, thickness of PU foam for the front floor, and thickness of PU foam for the rear floor, respectively. In this paper, the optimization procedure is a multi-objective optimization. Therefore, gray relational analysis (GRA) is applied to decide the optimal combination of sound package parameters. Furthermore, the principal component analysis (PCA) is used to calculate the weighting values which are corresponding to multiple performance characteristics. Then, the results of the confirmation tests uncover that GRA coupled with principal analysis methods can effectively be applied to find the optimal combination of the thickness of the sound packages at different positions for a passenger car. Thus, the proposed method can be a useful tool to improve the automotive interior middle frequency noise and lower the weight of the sound packages. Additionally, it will also be useful for automotive manufactures and designers in other fields.

  19. Role of the frequency of blood CD4+ CXCR5+ CCR6+ T cells in autoimmunity in patients with Sjögren’s syndrome

    International Nuclear Information System (INIS)

    Highlights: ► The frequency of CD4+ CXCR5+ CCR6+ T cells increased in pSS patients and positively correlated with autoantibodies in the blood. ► CD4+ CXCR5+ CCR6+ T cells in blood invariably coexpressed PD-1, ICOS, CD40L, Bcl-6 and secreted IL-21 after stimulated by PHA. ► CD4+ CXCR5+ CCR6+ Tfh cells in blood may be suitable biomarkers for the evaluation of the active immune stage of pSS patients. -- Abstract: The blood CD4+ CXCR5+ T cells, known as “circulating” Tfh, have been shown to efficiently induce naïve B cells to produce immunoglobulin. They play an important role in certain autoimmune diseases. In the present study, we show for the first time that the frequency of CD4+ CXCR5+ T cells is increased in pSS patients and positively correlated with autoantibodies in the blood. The concentration of Th17-like subsets (CD4+ CXCR5+ CCR6+) in pSS patients was found to be significantly higher than in healthy controls. Functional assays showed that activated Th17-like subtypes in the blood display the key features of Tfh cells, including invariably coexpressed PD-1, ICOS, CD40L and IL-21. Th17 subsets were found to highly express Bcl-6 protein and Th1 and Th2 were not. Bcl-6 is believed to be a master transforming factor for Tfh cell differentiation and facilitate B cell proliferation and somatic hypermutation within the germinal center. These data indicate that Th17 subsets of CD4+ CXCR5+ T cells in the blood may participate in the antibody-related immune responses and that high frequency of CD4+ CXCR5+ CCR6+ Tfh cells in blood may be suitable biomarkers for the evaluation of the active immune stage of pSS patients. It might provide insights into the pathogenesis and perhaps help researchers identify novel therapeutic targets for pSS.

  20. Role of the frequency of blood CD4{sup +} CXCR5{sup +} CCR6{sup +} T cells in autoimmunity in patients with Sjoegren's syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xue-yi; Wu, Zhen-biao; Ding, Jin; Zheng, Zhao-hui [Department of Clinical Immunology, State key Discipline of Cell Biology, Xi-jing Hospital, Fourth Military Medical University, Shaanxi Province (China); Li, Xiao-yan [Department of Endocrine and Metabolic Diseases, Shaanxi Provincial People' s Hospital, Xi' an, Shaanxi Province (China); Chen, Li-na [Department of Clinical Immunology, State key Discipline of Cell Biology, Xi-jing Hospital, Fourth Military Medical University, Shaanxi Province (China); Zhu, Ping, E-mail: zhuping@fmmu.edu.cn [Department of Clinical Immunology, State key Discipline of Cell Biology, Xi-jing Hospital, Fourth Military Medical University, Shaanxi Province (China)

    2012-06-01

    Highlights: Black-Right-Pointing-Pointer The frequency of CD4{sup +} CXCR5{sup +} CCR6{sup +} T cells increased in pSS patients and positively correlated with autoantibodies in the blood. Black-Right-Pointing-Pointer CD4{sup +} CXCR5{sup +} CCR6{sup +} T cells in blood invariably coexpressed PD-1, ICOS, CD40L, Bcl-6 and secreted IL-21 after stimulated by PHA. Black-Right-Pointing-Pointer CD4{sup +} CXCR5{sup +} CCR6{sup +} Tfh cells in blood may be suitable biomarkers for the evaluation of the active immune stage of pSS patients. -- Abstract: The blood CD4{sup +} CXCR5{sup +} T cells, known as 'circulating' Tfh, have been shown to efficiently induce naieve B cells to produce immunoglobulin. They play an important role in certain autoimmune diseases. In the present study, we show for the first time that the frequency of CD4{sup +} CXCR5{sup +} T cells is increased in pSS patients and positively correlated with autoantibodies in the blood. The concentration of Th17-like subsets (CD4{sup +} CXCR5{sup +} CCR6{sup +}) in pSS patients was found to be significantly higher than in healthy controls. Functional assays showed that activated Th17-like subtypes in the blood display the key features of Tfh cells, including invariably coexpressed PD-1, ICOS, CD40L and IL-21. Th17 subsets were found to highly express Bcl-6 protein and Th1 and Th2 were not. Bcl-6 is believed to be a master transforming factor for Tfh cell differentiation and facilitate B cell proliferation and somatic hypermutation within the germinal center. These data indicate that Th17 subsets of CD4{sup +} CXCR5{sup +} T cells in the blood may participate in the antibody-related immune responses and that high frequency of CD4{sup +} CXCR5{sup +} CCR6{sup +} Tfh cells in blood may be suitable biomarkers for the evaluation of the active immune stage of pSS patients. It might provide insights into the pathogenesis and perhaps help researchers identify novel therapeutic targets for pSS.

  1. Estimation of size of red blood cell aggregates using backscattering property of high-frequency ultrasound: In vivo evaluation

    Science.gov (United States)

    Kurokawa, Yusaku; Taki, Hirofumi; Yashiro, Satoshi; Nagasawa, Kan; Ishigaki, Yasushi; Kanai, Hiroshi

    2016-07-01

    We propose a method for assessment of the degree of red blood cell (RBC) aggregation using the backscattering property of high-frequency ultrasound. In this method, the scattering property of RBCs is extracted from the power spectrum of RBC echoes normalized by that from the posterior wall of a vein. In an experimental study using a phantom, employing the proposed method, the sizes of microspheres 5 and 20 µm in diameter were estimated to have mean values of 4.7 and 17.3 µm and standard deviations of 1.9 and 1.4 µm, respectively. In an in vivo experimental study, we compared the results between three healthy subjects and four diabetic patients. The average estimated scatterer diameters in healthy subjects at rest and during avascularization were 7 and 28 µm, respectively. In contrast, those in diabetic patients receiving both antithrombotic therapy and insulin therapy were 11 and 46 µm, respectively. These results show that the proposed method has high potential for clinical application to assess RBC aggregation, which may be related to the progress of diabetes.

  2. Determination of the frequency of polymorphisms in genes related to the genome stability maintenance of the population residing at Monte Alegre, PA (Brazil) municipality

    International Nuclear Information System (INIS)

    The human exposure to ionizing radiation coming from natural sources is an inherent feature of human life on earth, for man and all living things have always been exposed to these sources. Ionizing radiation is a known genotoxic agent which can affect the genomic stability and genes related to DNA repair may play a role when they have committed certain polymorphism. This study aimed to analyze the frequency of polymorphisms (SNPs) in genes of DNA repair and cell cycle control: hOGG1 (Ser326Cys), XRCC3 (Thr241 Met) and p53 (Arg72Pro) in saliva samples from a population located Monte Alegre, state of Para were collected in August 2008 and 40 samples of men and 46 samples of women, adding a total of 86 samples. By RFLP was determined the frequency of homozygous genotypes and / or heterozygous for polymorphic genes. The I)OGG1 gene was 5% of the allele 326Cys, XRCC3 gene found about 21 % of the allele 241 Met and p53 gene showed 40.8% of the 72Pro allele. And the genotype frequencies of individuals for the three genes were 91.04%, 88.06% and 59.7% for homozygous wild genotype, 5.97%, 11.94% and 22.39% for heterozygote genotype and 2,99%, zero and 17:91% for homozygous polymorphic hOGG1 genes respectively, XRCC3, p53. These values are similar to those found in previous studies. The influence of these polymorphisms, which are involved in DNA repair and consequent genotoxicity induced by radiation depends on dose and exposure factors such as smoking, which is statistically a factor in public health surveillance in the region. This study gathered information and molecular epidemiology in Monte Alegre, that help to characterization of local population. (author)

  3. High-frequency low-level diode laser irradiation promotes proliferation and migration of primary cultured human gingival epithelial cells.

    Science.gov (United States)

    Ejiri, Kenichiro; Aoki, Akira; Yamaguchi, Yoko; Ohshima, Mitsuhiro; Izumi, Yuichi

    2014-07-01

    In periodontal therapy, the use of low-level diode lasers has recently been considered to improve wound healing of the gingival tissue. However, its effects on human gingival epithelial cells (HGECs) remain unknown. The aim of the present study was to examine whether high-frequency low-level diode laser irradiation stimulates key cell responses in wound healing, proliferation and migration, in primary cultured HGECs in vitro. HGECs were derived from seven independent gingival tissue specimens. Cultured HGECs were exposed to a single session of high-frequency (30 kHz) low-level diode laser irradiation with various irradiation time periods (fluence 5.7-56.7 J/cm(2)). After 20-24 h, cell proliferation was evaluated by WST-8 assay and [(3)H]thymidine incorporation assay, and cell migration was monitored by in vitro wound healing assay. Further, phosphorylation of the mitogen-activated protein kinase (MAPK) pathways after irradiation was investigated by Western blotting. The high-frequency low-level irradiation significantly increased cell proliferation and [(3)H]thymidine incorporation at various irradiation time periods. Migration of the irradiated cells was significantly accelerated compared with the nonirradiated control. Further, the low-level diode laser irradiation induced phosphorylation of MAPK/extracellular signal-regulated protein kinase (ERK) at 5, 15, 60, and 120 min after irradiation. Stress-activated protein kinases/c-Jun N-terminal kinase and p38 MAPK remained un-phosphorylated. The results show that high-frequency low-level diode laser irradiation promotes HGEC proliferation and migration in association with the activation of MAPK/ERK, suggesting that laser irradiation may accelerate gingival wound healing.

  4. Remarks on nonlinear relation among phases and frequencies in modulational instabilities of parallel propagating Alfvén waves

    Directory of Open Access Journals (Sweden)

    Y. Nariyuki

    2006-01-01

    Full Text Available Nonlinear relations among frequencies and phases in modulational instability of circularly polarized Alfvén waves are discussed, within the context of one dimensional, dissipation-less, unforced fluid system. We show that generation of phase coherence is a natural consequence of the modulational instability of Alfvén waves. Furthermore, we quantitatively evaluate intensity of wave-wave interaction by using bi-coherence, and also by computing energy flow among wave modes, and demonstrate that the energy flow is directly related to the phase coherence generation. We first discuss the modulational instability within the derivative nonlinear Schrödinger (DNLS equation, which is a subset of the Hall-MHD system including the right- and left-hand polarized, nearly degenerate quasi-parallel Alfvén waves. The dominant nonlinear process within this model is the four wave interaction, in which a quartet of waves in resonance can exchange energy. By numerically time integrating the DNLS equation with periodic boundary conditions, and by evaluating relative phase among the quartet of waves, we show that the phase coherence is generated when the waves exchange energy among the quartet of waves. As a result, coherent structures (solitons appear in the real space, while in the phase space of the wave frequency and the wave number, the wave power is seen to be distributed around a straight line. The slope of the line corresponds to the propagation speed of the coherent structures. Numerical time integration of the Hall-MHD system with periodic boundary conditions reveals that, wave power of transverse modes and that of longitudinal modes are aligned with a single straight line in the dispersion relation phase space, suggesting that efficient exchange of energy among transverse and longitudinal wave modes is realized in the Hall-MHD. Generation of the longitudinal wave modes violates the assumptions employed in deriving the DNLS such as the quasi

  5. The Frequency of Proliferative Stromal Cells in Adipose Tissue Varies Between Inbred Mouse Strains

    Directory of Open Access Journals (Sweden)

    Mo J

    2009-01-01

    Full Text Available Stromal cells derived from adipose tissue (ASCs can proliferate as undifferentiated cells with a fibroblast-like morphology in cell culture, or can be induced to differentiate into a variety of cell types including, adipipogenic, myogenic, neurogenic, osteogenic, chondrogenic and hepatic cells. There is increasing interest to understand the factors controlling the proliferation of ASCs since these cells might provide a readily available source of autologous stem/progenitor cells for cell therapy applications. To explore potential genetic factors that modify the properties of ASCs, we tried to identify relevant properties of ASCs that differ between inbred mouse strains. Plating cells in a modified colony forming assay indicates that the percentage of high proliferative cells among ASCs differs more than 2-fold between 129x1/svj and C57Bl/6J mice. The identification of genetic factors affecting the proliferative capacity of stem cell populations could improve the efficacy of cell therapy.

  6. A KNOWLEDGE DISCOVERY STRATEGY FOR RELATING SEA SURFACE TEMPERATURES TO FREQUENCIES OF TROPICAL STORMS AND GENERATING PREDICTIONS OF HURRICANES UNDER 21ST-CENTURY GLOBAL WARMING SCENARIOS

    Data.gov (United States)

    National Aeronautics and Space Administration — A KNOWLEDGE DISCOVERY STRATEGY FOR RELATING SEA SURFACE TEMPERATURES TO FREQUENCIES OF TROPICAL STORMS AND GENERATING PREDICTIONS OF HURRICANES UNDER 21ST-CENTURY...

  7. Increased number and frequency of group 3 innate lymphoid cells in nonlesional psoriatic skin

    DEFF Research Database (Denmark)

    Dyring-Andersen, B; Geisler, Carsten; Agerbeck, C;

    2014-01-01

    patients with psoriasis compared with healthy skin and skin from patients with contact allergy to nickel. Furthermore, skin ILCs expressed high levels of the natural killer receptor NKG2D. NKG2D binds to stress-induced ligands, including major histocompatibility complex class I-related chain A, which we......BACKGROUND: Psoriasis is a common immune-mediated inflammatory disease that affects the skin and joints. The interleukin (IL)-23/IL-17A axis and IL-22 play key roles in the pathogenesis of psoriasis. IL-23-responsive innate lymphoid cells (ILCs) with a high capacity to produce IL-17 and/or IL-22...... have recently been identified and associated with inflammatory bowel diseases. The occurrence and role of ILCs in human skin are poorly understood. OBJECTIVES: To describe the prevalence of the different ILC subpopulations in skin from healthy controls and patients with psoriasis or allergy to nickel...

  8. High frequency of tumor cells with nuclear Egr-1 protein expression in human bladder cancer is associated with disease progression

    International Nuclear Information System (INIS)

    Egr-1 (early growth response-1 transcription factor) has been proposed to be involved in invasion and metastasis processes of human bladder cancer, but Egr-1 protein expression levels in human bladder cancer have not been investigated. In the present study we investigated the expression levels of Egr-1 protein in early stages of human bladder cancer and correlated it to later progression. Expression of Egr-1 protein in human bladder cancer was examined by immunohistochemistry, on a tissue microarray constructed from tumors from 289 patients with non-muscle invasive urothelial bladder cancer. The frequency of tumor cells with nuclear Egr-1 immunolabelling correlated to bladder cancer stage, grade and to later progression to muscle-invasive bladder cancer (T2-4). Stage T1 tumors exhibited significantly higher frequencies of tumor cells with nuclear Egr-1 immunolabelling than Ta tumors (P = 0.001). Furthermore, Kaplan-Meier survival analysis showed that a high frequency of tumor cells with nuclear Egr-1 immunolabelling was significantly associated with a higher risk of progression to stage T2-4 (log-rank test, P = 0.035). Tumor cells with nuclear Egr-1 immunolabelling were found to localize at the tumor front in some of the tumor biopsies. The results from this study support a potential involvement of Egr-1 in the progression from non-muscle invasive bladder cancers to muscle invasive bladder cancer

  9. Cell to Cell Variability of Radiation-Induced Foci: Relation between Observed Damage and Energy Deposition.

    Directory of Open Access Journals (Sweden)

    Gaëtan Gruel

    Full Text Available Most studies that aim to understand the interactions between different types of photon radiation and cellular DNA assume homogeneous cell irradiation, with all cells receiving the same amount of energy. The level of DNA damage is therefore generally determined by averaging it over the entire population of exposed cells. However, evaluating the molecular consequences of a stochastic phenomenon such as energy deposition of ionizing radiation by measuring only an average effect may not be sufficient for understanding some aspects of the cellular response to this radiation. The variance among the cells associated with this average effect may also be important for the behaviour of irradiated tissue. In this study, we accurately estimated the distribution of the number of radiation-induced γH2AX foci (RIF per cell nucleus in a large population of endothelial cells exposed to 3 macroscopic doses of gamma rays from 60Co. The number of RIF varied significantly and reproducibly from cell to cell, with its relative standard deviation ranging from 36% to 18% depending on the macroscopic dose delivered. Interestingly, this relative cell-to-cell variability increased as the dose decreased, contrary to the mean RIF count per cell. This result shows that the dose effect, in terms of the number of DNA lesions indicated by RIF is not as simple as a purely proportional relation in which relative SD is constant with dose. To analyse the origins of this observed variability, we calculated the spread of the specific energy distribution for the different target volumes and subvolumes in which RIF can be generated. Variances, standard deviations and relative standard deviations all changed similarly from dose to dose for biological and calculated microdosimetric values. This similarity is an important argument that supports the hypothesis of the conservation of the association between the number of RIF per nucleus and the specific energy per DNA molecule. This

  10. Methamphetamine decreases CD4 T cell frequency and alters pro-inflammatory cytokine production in a model of drug abuse.

    Science.gov (United States)

    Mata, Mariana M; Napier, T Celeste; Graves, Steven M; Mahmood, Fareeha; Raeisi, Shohreh; Baum, Linda L

    2015-04-01

    The reason co-morbid methamphetamine use and HIV infection lead to more rapid progression to AIDS is unclear. We used a model of methamphetamine self-administration to measure the effect of methamphetamine on the systemic immune system to better understand the co-morbidity of methamphetamine and HIV. Catheters were implanted into the jugular veins of male, Sprague Dawley rats so they could self-administer methamphetamine (n=18) or be given saline (control; n=16) for 14 days. One day after the last operant session, blood and spleens were collected. We measured serum levels of pro-inflammatory cytokines, intracellular IFN-γ and TNF-α, and frequencies of CD4(+), CD8(+), CD200(+) and CD11b/c(+) lymphocytes in the spleen. Rats that self-administered methamphetamine had a lower frequency of CD4(+) T cells, but more of these cells produced IFN-γ. Methamphetamine did not alter the frequency of TNF-α-producing CD4(+) T cells. Methamphetamine using rats had a higher frequency of CD8(+) T cells, but fewer of them produced TNF-α. CD11b/c and CD200 expression were unchanged. Serum cytokine levels of IFN-γ, TNF-α and IL-6 in methamphetamine rats were unchanged. Methamphetamine lifetime dose inversely correlated with serum TNF-α levels. Our data suggest that methamphetamine abuse may exacerbate HIV disease progression by activating CD4 T cells, making them more susceptible to HIV infection, and contributing to their premature demise. Methamphetamine may also increase susceptibility to HIV infection, explaining why men who have sex with men (MSM) and frequently use methamphetamine are at the highest risk of HIV infection.

  11. Lens Epithelial Cell Proliferation and Cell Density in Human Age-related Cataract

    Institute of Scientific and Technical Information of China (English)

    Xialin Liu; Yizhi Liu; Jianliang Zheng; Qiang Huang; Huling Zheng

    2000-01-01

    Purpose: To discuss the potential effect of the lens epithelial cell proliferation in age-related cataract.Methods: In vitro cell proliferation was assayed by MTT method to evaluate the lens epithelial cell density, index, and proliferation capacity in normal lens and all kinds of age-related cataract. Capsulotomy specimens from all kinds of patients who underwent cataract phacoemulsification extraction surgery were compared with the lens epithelial specimens from non-cataract lenses of Eye Bank eyes.Results: Lens epithelial cell density of central anterior capsule (LECD) in female normal lens was higher than that in male, LECD in nuclear cataract( > NⅢ ) was higher than that in normal lens, but in the mature cortical cataract, LF CD was lower. Mitotic index of three kinds of age-related cataracts in vivo had no statistical difference, neither did cell proliferation capacity of cultivated cells in vitro.Conclusion: The individual difference of lens epithelial cell density and proliferation capacity in vivo may be an important underlying cause for senile cataract in the cellular level, especially for nuclear cataract.

  12. Storage Free Smart Energy Management for Frequency Control in a Diesel-PV-Fuel Cell-Based Hybrid AC Microgrid.

    Science.gov (United States)

    Sekhar, P C; Mishra, S

    2016-08-01

    This paper proposes a novel, smart energy management scheme for a microgrid, consisting of a diesel generator and power electronic converter interfaced renewable energy-based generators, such as photovoltaic (PV) and fuel cell, for frequency regulation without any storage. In the proposed strategy, output of the PV is controlled in coordination with other generators using neurofuzzy controller, either only for transient frequency regulation or for both transient and steady-state frequency regulation, depending on the load demand, thereby eliminating the huge storage requirements. The option of demand response control is also explored along with the generation control. For accurate and quick tracking of maximum power point and its associated reserve power from the PV generator, this paper also proposes a novel adaptive-predictor-corrector-based tracking mechanism. PMID:26011895

  13. Frequency dispersion in the admittance of the polycrystalline Cu/sub 2/S/CdS solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Hmurcik, L.V.; Serway, R.A.

    1987-01-15

    We measured the admittance versus frequency (fless than or equal to100 kHz) for the Cu/sub 2/S/CdS solar cell. In the dark, the dispersion fits a model of a simple Debye capacitor, with deviation due to grain-boundary scattering at low frequencies. Under illumination, the dispersion becomes a function of surface roughness. Modeled in fractal geometry, the admittance varies as ( j..omega..)/sup m/. A second term of this type occurs at high frequencies and at illuminations greater than 0.1% AM1. In this case, the depletion layer extends deep into the CdS due to insufficient charge states at the interface.

  14. Multi-service small-cell cloud wired/wireless access network based on tunable optical frequency comb

    Science.gov (United States)

    Xiang, Yu; Zhou, Kun; Yang, Liu; Pan, Lei; Liao, Zhen-wan; Zhang, Qiang

    2015-11-01

    In this paper, we demonstrate a novel multi-service wired/wireless integrated access architecture of cloud radio access network (C-RAN) based on radio-over-fiber passive optical network (RoF-PON) system, which utilizes scalable multiple- frequency millimeter-wave (MF-MMW) generation based on tunable optical frequency comb (TOFC). In the baseband unit (BBU) pool, the generated optical comb lines are modulated into wired, RoF and WiFi/WiMAX signals, respectively. The multi-frequency RoF signals are generated by beating the optical comb line pairs in the small cell. The WiFi/WiMAX signals are demodulated after passing through the band pass filter (BPF) and band stop filter (BSF), respectively, whereas the wired signal can be received directly. The feasibility and scalability of the proposed multi-service wired/wireless integrated C-RAN are confirmed by the simulations.

  15. A higher frequency of circulating IL-22(+CD4(+ T cells in Chinese patients with newly diagnosed Hashimoto's thyroiditis.

    Directory of Open Access Journals (Sweden)

    Hui Guo

    Full Text Available BACKGROUND: IL-22 and IL-17A are implicated in the pathogenesis of autoimmune diseases. However, the role of IL-22(+ and IL-17A(+ CD4(+ T cells in the pathogenesis of Hashimoto's thyroiditis (HT is not fully understood. This study investigates serum IL-22 and IL-17A levels and determines the frequency of circulating IL-22(+ CD4(+ T cells in HT patients to understand their roles in the pathogenesis of HT. METHODS: The levels of serum IL-22, IL-17A and IFN-γ and the frequency of circulating IL-22(+CD4(+ and IL-17A(+CD4(+ T cells in 17 HT patients and 17 healthy controls (HC were determined by enzyme-linked immunosorbent assay (ELISA and flow cytometry. The levels of serum free triiodothyronine (FT4, free thyroxine (FT3, thyroid stimulating hormone (TSH, anti-thyroid peroxidase (TPO and anti-thyroglobulin antibodies (TgAb by chemiluminescent enzyme immunoassay and radioimmunoassay. RESULTS: The percentages of circulating IL-22(+CD4(+ and IL-17(+CD4(+ T cells (p<0.0001, p<0.0001 and the levels of serum IL-22, IL-17A and IFN-γ (p<0.0001, p<0.0001, p = 0.0210 in the HT patients were significantly higher than that in the HC. The percentages of IL-22(+CD4(+ T cells were positively correlated with Th17 cells (r = 0.8815, p<0.0001 and IL-17A(+IL-22(+CD4(+ T cells (r = 0.8914, p<0.0001, but were negatively correlated with Th1 cells (r = -0.6110, p<0.0092 in the HT patients. The percentages of Th22 cells, Th17 cells and IL-17A(+IL-22(+CD4(+ T cells were negatively correlated with the levels of serum TSH in the HT patients (r = -0.8402, p<0.0001; r = -0.8589, p<0.0001; r = -0.8289 p<0.0001, respectively. CONCLUSIONS: A higher frequency of circulating IL-22(+CD4(+ and IL-17A(+CD4(+ T cells may be associated with the development of HT in Chinese patients.

  16. Age related differences in dynamics of specific memory B cell populations after clinical pertussis infection.

    Directory of Open Access Journals (Sweden)

    Inonge van Twillert

    Full Text Available For a better understanding of the maintenance of immune mechanisms to Bordetella pertussis (Bp in relation to age, we investigated the dynamic range of specific B cell responses in various age-groups at different time points after a laboratory confirmed pertussis infection. Blood samples were obtained in a Dutch cross sectional observational study from symptomatic pertussis cases. Lymphocyte subpopulations were phenotyped by flowcytometry before and after culture. Memory B (Bmem cells were differentiated into IgG antibody secreting cells (ASC by polyclonal stimulation and detected by an ELISPOT assay specific for pertussis antigens pertussis toxin (Ptx, filamentous haemagglutinin (FHA and pertactin (Prn. Bp antigen specific IgG concentrations in plasma were determined using multiplex technology. The majority of subjects having experienced a clinical pertussis episode demonstrated high levels of both Bp specific IgG and Bmem cell levels within the first 6 weeks after diagnosis. Significantly lower levels were observed thereafter. Waning of cellular and humoral immunity to maintenance levels occurred within 9 months after antigen encounter. Age was found to determine the maximum but not base-line frequencies of Bmem cell populations; higher levels of Bmem cells specific for Ptx and FHA were reached in adults and (pre- elderly compared to under-fours and schoolchildren in the first 6 weeks after Bp exposure, whereas not in later phases. This age effect was less obvious for specific IgG levels. Nonetheless, subjects' levels of specific Bmem cells and specific IgG were weakly correlated. This is the first study to show that both age and closeness to last Bp encounter impacts the size of Bp specific Bmem cell and plasma IgG levels.

  17. The effects of sex, age and cigarette smoking on micronucleus and degenerative nuclear alteration frequencies in human buccal cells of healthy Bosnian subjects

    OpenAIRE

    Hilada Nefić; Jasmin Mušanović; Kemajl Kurteshi; Enida Prutina; Elvira Turcalo

    2013-01-01

    Introduction: This study was performed to establish a baseline value of micronucleus frequency in buccal cells and to estimate the impact of the most common factors (sex and age, and smoking) on micronucleus and degenerative nuclear alteration frequencies in the sample of healthy Bosnian subjects.Methods: The Buccal Micronucleus Cytome (BMCyt) assay, based on scoring not only micronucleus frequency but also other genome damage markers, dead or degenerated cells, provides a measure of cytotoxi...

  18. Evaluation of Bone Marrow in 143 Lymphomas: The Relative Frequency and Pattern of Involvement, Secondary Myelopathies, Pitfalls and Diagnostic Validity

    International Nuclear Information System (INIS)

    The aim of the present study is to assess the frequency of bone marrow (BM) involvement by both bone marrow aspirate and biopsy (BMA and BMB, respectively) procedures in established cases of lymphomas at initial presentation, and to study the relative frequency of marrow disease in relation to lymphoma types, patterns of infiltration and the 2ry associated changes, as well as the diagnostic challenges. Moreover, the diagnostic validity of BMA is tested taking the results of the BMB as the true test results, in order to determine the role of each procedure in the diagnostic approach of marrow infiltration. Patients and Method: This is a retrospective study carried out on 143 non consecutive Egyptian patients with lymphomas obtained from a private series during the years 2005 to 2008. Criteria of inclusion included the availability of full medical records and material (medical and pathological), patient consent, nodal disease with no therapy prior to BM sampling, except in 7 patients who had another 2nd BMB following therapy. BMA and BMB were performed as part of the routine workup for diagnosis and staging of lymphoma. The patients had a male to female sex ratio of 2.6:1 and a wide age range from 4 to 74 years. Results: In the present series, 64 cases out of the 143 lymphoma patients studied (44.8%) had a BM disease. Involvement was mostly bilateral (80%). Patients older than 40 years showed higher incidence of bone marrow involvement. There was complete concordance (100%) between both diagnostic procedures in the detection of 76 marrow disease-free lymphoma patients. BMA showed no false positive results and a low rate of deference that makes of it an ideal screening test. Three deferred smears of CLL for BMB diagnosis were all positive for involvement. However, in a total number of 64 BMB positive patients, aspirates could only identify lymphoma involvement in 42 lymphoma patients and missed 22 patients with a BM disease, with an overall sensitivity rate of 65

  19. Frequencies of maternal red blood cell alloantibodies in Port Harcourt, Nigeria

    OpenAIRE

    Jeremiah Zaccheaus; Mordi Augustina; Buseri Fiekumo; Adias Teddy

    2011-01-01

    Background: Alloantibodies of clinical importance can cause transfusion reactions or hemolytic disease of the fetus and newborn (HDFN). The frequencies of these antibodies have not been reported in our locality. Aims: To determine the frequency of occurrence of alloantibodies among pregnant women in Port Harcourt, Nigeria. Settings and Design: This is a prospective study, which was carried out in the Braithwaite Memorial Specialist Hospital, Port Harcourt, Nigeria. Materials and Methods: Scre...

  20. Relative position determination of a lunar rover using high-accuracy multi-frequency same-beam VLBI

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Multi-frequency same-beam VLBI means that two explorers with a small separation angle are simultaneously observed with the main beam of receiving antennas. In the same-beam VLBI, the differential phase delay between two explorers and two receiving telescopes can be obtained with a small error of several picoseconds. The differential phase delay, as the observable of the same-beam VLBI, gives the separation angular information of the two explorers in the celestial sphere. The two-dimensional relative position on the plane-of-sky can thus be precisely determined with an error of less than 1 m for a distance of 3.8×105 km far away from the earth, by using the differential phase delay obtained with the four Chinese VLBI stations. The relative position of a lunar rover on the lunar surface can be determined with an error of 10 m by using the differential phase delay data and the range data for the lander when the lunar topography near the rover and the lander can be determined with an error of 10 m.

  1. Relation Between the Cell Volume and the Cell Cycle Dynamics in Mammalian cell

    Science.gov (United States)

    Magno, A. C. G.; Oliveira, I. L.; Hauck, J. V. S.

    2016-08-01

    The main goal of this work is to add and analyze an equation that represents the volume in a dynamical model of the mammalian cell cycle proposed by Gérard and Goldbeter (2011) [1]. The cell division occurs when the cyclinB/Cdkl complex is totally degraded (Tyson and Novak, 2011)[2] and it reaches a minimum value. At this point, the cell is divided into two newborn daughter cells and each one will contain the half of the cytoplasmic content of the mother cell. The equations of our base model are only valid if the cell volume, where the reactions occur, is constant. Whether the cell volume is not constant, that is, the rate of change of its volume with respect to time is explicitly taken into account in the mathematical model, then the equations of the original model are no longer valid. Therefore, every equations were modified from the mass conservation principle for considering a volume that changes with time. Through this approach, the cell volume affects all model variables. Two different dynamic simulation methods were accomplished: deterministic and stochastic. In the stochastic simulation, the volume affects every model's parameters which have molar unit, whereas in the deterministic one, it is incorporated into the differential equations. In deterministic simulation, the biochemical species may be in concentration units, while in stochastic simulation such species must be converted to number of molecules which are directly proportional to the cell volume. In an effort to understand the influence of the new equation a stability analysis was performed. This elucidates how the growth factor impacts the stability of the model's limit cycles. In conclusion, a more precise model, in comparison to the base model, was created for the cell cycle as it now takes into consideration the cell volume variation

  2. A low phase noise microwave frequency synthesis for a high-performance cesium vapor cell atomic clock

    Energy Technology Data Exchange (ETDEWEB)

    François, B.; Boudot, R. [FEMTO-ST, CNRS, Université de Franche-Comté, 26 chemin de l' Epitaphe, 25030 Besançon (France); Calosso, C. E. [INRIM, Strada delle Cacce 91, 10135 Torino (Italy); Danet, J. M. [LNE-SYRTE, Observatoire de Paris, CNRS-UPMC, 61 avenue de l' Observatoire, 75014 Paris (France)

    2014-09-15

    We report the development, absolute phase noise, and residual phase noise characterization of a 9.192 GHz microwave frequency synthesis chain devoted to be used as a local oscillator in a high-performance cesium vapor cell atomic clock based on coherent population trapping (CPT). It is based on frequency multiplication of an ultra-low phase noise 100 MHz oven-controlled quartz crystal oscillator using a nonlinear transmission line-based chain. Absolute phase noise performances of the 9.192 GHz output signal are measured to be −42, −100, −117 dB rad{sup 2}/Hz and −129 dB rad{sup 2}/Hz at 1 Hz, 100 Hz, 1 kHz, and 10 kHz offset frequencies, respectively. Compared to current results obtained in a state-of-the-art CPT-based frequency standard developed at LNE-SYRTE, this represents an improvement of 8 dB and 10 dB at f = 166 Hz and f = 10 kHz, respectively. With such performances, the expected Dick effect contribution to the atomic clock short term frequency stability is reported at a level of 6.2 × 10{sup −14} at 1 s integration time, that is a factor 3 higher than the atomic clock shot noise limit. Main limitations are pointed out.

  3. Epigenetic features of testicular germ cell tumours in relation to epigenetic characteristics of foetal germ cells

    DEFF Research Database (Denmark)

    Kristensen, Dina Graae; Skakkebæk, Niels E; Rajpert-De Meyts, Ewa;

    2013-01-01

    Foetal development of germ cells is a unique biological process orchestrated by cellular specification, migration and niche development in concert with extensive epigenetic and transcriptional programs. Many of these processes take place early in foetal life and are hence very difficult to study....... In this review, we will focus on current knowledge of the epigenetics of CIS cells and relate it to the epigenetic changes occurring in early developing germ cells of mice during specification, migration and colonization. We will focus on DNA methylation and some of the best studied histone modifications like H3......K9me2, H3K27me3 and H3K9ac. We also show that CIS cells contain high levels of H3K27ac, which is known to mark active enhancers. Proper epigenetic reprogramming seems to be a pre-requisite of normal foetal germ cell development and we propose that alterations in these programs may be a pathogenic...

  4. Differences in the Frequency of Cytokine-Producing Cells in Antigenemic and Nonantigenemic Individuals with Bancroftian Filariasis

    OpenAIRE

    de Almeida, Adriana B.; e Silva, Maria Carmelita Maia; Braga, Cynthia; Freedman, David O

    1998-01-01

    Individuals with clinical manifestations of lymphatic filariasis may be currently infected or not. Twenty-five individuals from a Wuchereria bancrofti-endemic area of Brazil were classified as being asymptomatic microfilaremic individuals, antigenemic individuals with clinical filariasis, or nonantigenemic individuals with clinical filariasis. Intracellular cytokine staining of mitogen-stimulated peripheral blood mononuclear cells (PBMC) showed that the frequency of either gamma interferon (I...

  5. Assessment of micronucleus frequency in exfoliated buccal epithelial cells among fisher folks exposed to mine tailings in Marinduque Island, Philippines

    Institute of Scientific and Technical Information of China (English)

    Elena M Ragragio; Celeste P Belleza; Mark C Narciso; Glenn L Sia Su

    2010-01-01

    Objective:To evaluate the potential toxic effects of mine tailings exposure among the fisher folks residing near and far from the Calancan Bay, Marinduque, using the micronucleus assay as an endpoint.Methods: The fisher folks residing near and far from the Calancan Bay were interviewed and the presence and frequency of cells with micronucleus in exfoliated buccal epithelial cells were examined.Results: Results showed that the prevalence of cells with micronucleus was higher among the fisher folks who were directly exposed to the mine tailings as compared with those fisher folks who reside in a community without exposure of mine tailings and history of mining (P<0.05).Conclusions: The presence and the significant difference in the cells with micronuclei observed near the Calancan Bay could possibly indicate a prolonged chemical stress caused by the toxic heavy metals in the mine tailings and the environment.

  6. Ion mobility mass spectrometry of peptide, protein, and protein complex ions using a radio-frequency confining drift cell.

    Science.gov (United States)

    Allen, Samuel J; Giles, Kevin; Gilbert, Tony; Bush, Matthew F

    2016-02-01

    Ion mobility mass spectrometry experiments enable the characterization of mass, assembly, and shape of biological molecules and assemblies. Here, a new radio-frequency confining drift cell is characterized and used to measure the mobilities of peptide, protein, and protein complex ions. The new drift cell replaced the traveling-wave ion mobility cell in a Waters Synapt G2 HDMS. Methods for operating the drift cell and determining collision cross section values using this experimental set up are presented within the context of the original instrument control software. Collision cross sections for 349 cations and anions are reported, 155 of which are for ions that have not been characterized previously using ion mobility. The values for the remaining ions are similar to those determined using a previous radio-frequency confining drift cell and drift tubes without radial confinement. Using this device under 2 Torr of helium gas and an optimized drift voltage, denatured and native-like ions exhibited average apparent resolving powers of 14.2 and 16.5, respectively. For ions with high mobility, which are also low in mass, the apparent resolving power is limited by contributions from ion gating. In contrast, the arrival-time distributions of low-mobility, native-like ions are not well explained using only contributions from ion gating and diffusion. For those species, the widths of arrival-time distributions are most consistent with the presence of multiple structures in the gas phase. PMID:26739109

  7. Ion mobility mass spectrometry of peptide, protein, and protein complex ions using a radio-frequency confining drift cell.

    Science.gov (United States)

    Allen, Samuel J; Giles, Kevin; Gilbert, Tony; Bush, Matthew F

    2016-02-01

    Ion mobility mass spectrometry experiments enable the characterization of mass, assembly, and shape of biological molecules and assemblies. Here, a new radio-frequency confining drift cell is characterized and used to measure the mobilities of peptide, protein, and protein complex ions. The new drift cell replaced the traveling-wave ion mobility cell in a Waters Synapt G2 HDMS. Methods for operating the drift cell and determining collision cross section values using this experimental set up are presented within the context of the original instrument control software. Collision cross sections for 349 cations and anions are reported, 155 of which are for ions that have not been characterized previously using ion mobility. The values for the remaining ions are similar to those determined using a previous radio-frequency confining drift cell and drift tubes without radial confinement. Using this device under 2 Torr of helium gas and an optimized drift voltage, denatured and native-like ions exhibited average apparent resolving powers of 14.2 and 16.5, respectively. For ions with high mobility, which are also low in mass, the apparent resolving power is limited by contributions from ion gating. In contrast, the arrival-time distributions of low-mobility, native-like ions are not well explained using only contributions from ion gating and diffusion. For those species, the widths of arrival-time distributions are most consistent with the presence of multiple structures in the gas phase.

  8. Increased frequency of spontaneous neoplastic transformation in progeny of bystander cells from cultures exposed to densely ionizing radiation.

    Directory of Open Access Journals (Sweden)

    Manuela Buonanno

    Full Text Available An increased risk of carcinogenesis caused by exposure to space radiation during prolonged space travel is a limiting factor for human space exploration. Typically, astronauts are exposed to low fluences of ionizing particles that target only a few cells in a tissue at any one time. The propagation of stressful effects from irradiated to neighboring bystander cells and their transmission to progeny cells would be of importance in estimates of the health risks of exposure to space radiation. With relevance to the risk of carcinogenesis, we investigated, in model C3H 10T½ mouse embryo fibroblasts (MEFs, modulation of the spontaneous frequency of neoplastic transformation in the progeny of bystander MEFs that had been in co-culture 10 population doublings earlier with MEFs exposed to moderate doses of densely ionizing iron ions (1 GeV/nucleon or sparsely ionizing protons (1 GeV. An increase (P<0.05 in neoplastic transformation frequency, likely mediated by intercellular communication through gap junctions, was observed in the progeny of bystander cells that had been in co-culture with cells irradiated with iron ions, but not with protons.

  9. Effect of space flight on the frequency of micronuclei and expression of stress-responsive proteins in cultured mammalian cells

    International Nuclear Information System (INIS)

    Results of past space experiments suggest that the biological effect of space radiation could been hanced under microgravity in some cases, especially ininsects. To examine if such a synergistic effect of radiation and microgravity also exists in human cells, frequencies of chromosome instability and cellular levels of several stress-responsive proteins were analyzed incultured human and rodent cells afterspace flight. Human (MCF7 and ataxia telangiectasia(AT)2KY), mouse (m5S) and hamster (Syrian hamster embryo (SHE)) cell lines were loaded on the Space Shuttle Discovery (STS-95 mission) and grown during a 9-daymission. After landing, the micronuclei resulting from abnormal nuclear division and accumulationof stress-responsive proteins such as p53 and mitogen-activated protein kinases (MAPKs), which are involved in radiation-induced signal transduction cascades, were analyzed. The frequencies of micronucleiin all the four mammalian cell strains tested were not significantly different between flight and ground control samples. Also, the cellular amounts of p53, p21 (WAF1/SDI1/CIP1) and activated (phosphorylated) forms of three distinct MAPKs in MCF7 and m5S cells of flight samples were similar to those of ground control samples. These results indicated that anyeffect of space radiation, microgravity, or combination of both were not detectable, at least under thepresent experimental conditions. (author)

  10. Technical basis for evaluating electromagnetic and radio-frequency interference in safety-related I ampersand C systems

    International Nuclear Information System (INIS)

    This report discusses the development of the technical basis for the control of upsets and malfunctions in safety-related instrumentation and control (I ampersand C) systems caused by electromagnetic and radio-frequency interference (EMI/RFI) and power surges. The research was performed at the Oak Ridge National Laboratory (ORNL) and was sponsored by the USNRC Office of Nuclear Regulatory Research (RES). The motivation for research stems from the safety-related issues that need to be addressed with the application of advanced I ampersand C systems to nuclear power plants. Development of the technical basis centered around establishing good engineering practices to ensure that sufficient levels of electromagnetic compatibility (EMC) are maintained between the nuclear power plant's electronic and electromechanical systems known to be the source(s) of EMI/RFI and power surges. First, good EMC design and installation practices need to be established to control the impact of interference sources on nearby circuits and systems. These EMC good practices include circuit layouts, terminations, filtering, grounding, bonding, shielding, and adequate physical separation. Second, an EMI/RFI test and evaluation program needs to be established to outline the tests to be performed, the associated test methods to be followed, and carefully formulated acceptance criteria based on the intended environment to ensure that the circuit or system under test meets the recommended guidelines. Third, a program needs to be developed to perform confirmatory tests and evaluate the surge withstand capability (SWC) and of I ampersand C equipment connected to or installed in the vicinity of power circuits within the nuclear power plant. By following these three steps, the design and operability of safety-related I ampersand C systems against EMI/RFI and power surges can be evaluated, acceptance criteria can be developed, and appropriate regulatory guidance can be provided

  11. Technical basis for evaluating electromagnetic and radio-frequency interference in safety-related I&C systems

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, P.D.; Korsah, K. [Oak Ridge National Lab., TN (United States)

    1994-04-01

    This report discusses the development of the technical basis for the control of upsets and malfunctions in safety-related instrumentation and control (I&C) systems caused by electromagnetic and radio-frequency interference (EMI/RFI) and power surges. The research was performed at the Oak Ridge National Laboratory (ORNL) and was sponsored by the USNRC Office of Nuclear Regulatory Research (RES). The motivation for research stems from the safety-related issues that need to be addressed with the application of advanced I&C systems to nuclear power plants. Development of the technical basis centered around establishing good engineering practices to ensure that sufficient levels of electromagnetic compatibility (EMC) are maintained between the nuclear power plant`s electronic and electromechanical systems known to be the source(s) of EMI/RFI and power surges. First, good EMC design and installation practices need to be established to control the impact of interference sources on nearby circuits and systems. These EMC good practices include circuit layouts, terminations, filtering, grounding, bonding, shielding, and adequate physical separation. Second, an EMI/RFI test and evaluation program needs to be established to outline the tests to be performed, the associated test methods to be followed, and carefully formulated acceptance criteria based on the intended environment to ensure that the circuit or system under test meets the recommended guidelines. Third, a program needs to be developed to perform confirmatory tests and evaluate the surge withstand capability (SWC) and of I&C equipment connected to or installed in the vicinity of power circuits within the nuclear power plant. By following these three steps, the design and operability of safety-related I&C systems against EMI/RFI and power surges can be evaluated, acceptance criteria can be developed, and appropriate regulatory guidance can be provided.

  12. A stabilized 18 GHz chip-scale optical frequency comb at 2.8x10-16 relative inaccuracy

    OpenAIRE

    Huang, S.-W.; Yang, J.; Yu, M.; McGuyer, B. H.; Kwong, D. -L.; Zelevinsky, T.; Wong, C. W.

    2015-01-01

    Optical frequency combs, coherent light sources that connect optical frequencies with microwave oscillations, have become the enabling tool for precision spectroscopy, optical clockwork and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but four-wave-mixing in high-Q resonators have emerged as alternative platforms. Here we report the generation and full stabilization of CMOS-compatible optical frequency combs. The spira...

  13. Expression of cell cycle related genes in HL60 cells undergoing apoptosis by X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Hee [College of Medicine, Keimyung Univ., Taegu (Korea, Republic of); Park, In Kyu [College of Medicine, Kyungpook National Univ., Taegu (Korea, Republic of)

    1998-12-01

    To evaluate changes in expression of cell cycle related genes during apoptosis induced in HL60 cells by X-irradiation to understand molecular biologic aspects in mechanism of radiation therapy. HL-60 cell line (promyelocytic leukemia cell line was grown in culture media and irradiated with 8 Gy by linear accelerator (6 MV X-ray). At various times after irradiation, ranging from 3 to 48 hours were analyzed apoptotic DNA fragmentation assay for apoptosis and by western blot analysis and semi-quantitative RT-PCR for expression of cell cycle related genes (cyclin A, cyclin B, cyclin C, cyclin D1, cyclin E, cdc2, CDK2, CDK4, p16{sup INK4a}, p21{sup WAF1}, p27K{sup IP1}, E2F, PCNA and Rb). X-irradiation (8 Gy) induced apoptosis in HL-60 cell line. Cycline A protein increased after reaching its peak 48 h after radiation delivery and cyclin E, E2F, CDK2 and RB protein increased then decreased after radiation. Radiation induced up-regulation of the expression of E2F is due to mostly increase of phosphorylated retinoblastoma proteins (ppRb). Cyclin D1, PCNA, CDC1, CDK4 and p16{sup INK4a} protein underwent no significant change at any times after irradiation. There was not detected p21{sup WAF1} and p27{sup KIP1} protein. Cyclin A, B, C, mRNA decreased immediately after radiation and then increased at 12 h after radiation. Cyclin D1 mRNA increased immediately and then decreased with the lapse of time. CDK2 mRNA decreased at 3 h and increased at 6 h after radiation. CDK4 mRNA rapidly increased at 6 to 12 h after radiation. There was no change of expression of p16{sup INK4a} and not detected in expressin of p21{sup WAF1} and p27{sup KIP1} mRNA. We suggest that entry into S phaso may contribute to apoptosis of HL60 cells induced by irradiation. Increase of ppRb and decrease of pRb protein are related with radiation induced apoptosis of HL60 cells and tosis of HL60 cells induced by irradiation. Increase of ppRb and decrease of pRb protein are related with radiation induced

  14. Functional role of regulatory T cells in B cell lymphoma and related mechanisms.

    Science.gov (United States)

    Wu, Wei; Wan, Jun; Xia, Ruixiang; Huang, Zhenqi; Ni, Jing; Yang, Mingzhen

    2015-01-01

    B cell lymphoma (BCL) has a higher degree of malignancy and complicated pathogenic mechanism. Regulatory T cells (Treg cells) are known to exert certain immune suppression functions, in addition to immune mediating effects. Recent studies have revealed the role of Treg cells in pathogenesis and progression of multiple malignant tumors. This study therefore investigated the functional role and related mechanism of Treg cells in BCL. A cohort of thirty patients who were diagnosed with BCL in our hospital between January 2013 and December 2014. Another thirty healthy individuals were recruited. Peripheral blood mononuclear cells (PBMCs) were separated and analyzed for the ratio of CD4+/CD25+ Treg cells. The mRNA expression levels of Foxp3, transforming growth factor (TGF)-β1 and interleukin (IL)-10 genes were quantified by real-time PCR, while their serum levels were determined by enzyme-linked immunosorbent assay (ELISA). Meanwhile all laboratory indexes for patients were monitored during the complete remission (CR) stage. BCL patients significantly elevated ratio of CD4+/CD25+ Treg cells, which were decreased at CR stage. mRNA levels of Foxp3, TGF-β1 and IL-10, in addition to protein levels of TGF-β1 and IL-10 were potentiated in lymphoma patients but decreased in CR patients (Pregulating cytokines, thereby facilitating the pathogenesis and progression of lymphoma. PMID:26464657

  15. Nuclear abnormalities in cells from nasal epithelium: a promising assay to evaluate DNA damage related to air pollution in infants

    Directory of Open Access Journals (Sweden)

    Michelle Mergener

    2014-12-01

    Full Text Available OBJECTIVES: This study intends to provide a quick, easy, and inexpensive way to assess nuclear abnormalities such as micronuclei and bud frequencies; binucleated, karyorrhectic, karyolytic, pycnotic, and condensed chromatin cells in nasal scrapings of infants, which are particularly important for conducting genotoxic studies related to the inhaled atmosphere in pediatric populations. METHODS: Nasal swab samples were collected from 40 infants under 12 months of age using a small cytobrush. 2,000 cells from each infant sample were analyzed and classified according to the frequency of nuclear abnormalities. RESULTS: Rates of nuclear abnormalities found agree with values reported in other studies of neonates and children. This study found 0.13% of cells with micronuclei; 1.20% karyorrhexis; 0.03% pyknosis; 10.85% karyolysis; 1.11% condensed chromatin; 0.54 binucleated cells; and 0.02% nuclear bud. Differences were not observed between genders or environmental passive smoking, nor was any age correlation found. CONCLUSION: The assay proposed here is suitable for assessing the frequency of nuclear abnormalities from nasal cells in infants.

  16. VMP1 related autophagy and apoptosis in colorectal cancer cells: VMP1 regulates cell death

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Qinyi [Department of Ultrasonograph, Changshu No. 2 People’s Hospital, Changshu (China); Zhou, Hao; Chen, Yan [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China); Shen, Chenglong [Department of General Surgery, Changshu No. 2 People’s Hospital, Changshu (China); He, Songbing; Zhao, Hua; Wang, Liang [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China); Wan, Daiwei, E-mail: 372710369@qq.com [Department of Hepatobiliary Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou (China); Gu, Wen, E-mail: 505339704@qq.com [Department of General Surgery, The First Affiliated Hospital of Soochow University, Suzhou (China)

    2014-01-17

    Highlights: •This research confirmed VMP1 as a regulator of autophagy in colorectal cancer cell lines. •We proved the pro-survival role of VMP1-mediated autophagy in colorectal cancer cell lines. •We found the interaction between VMP1 and BECLIN1 also existing in colorectal cancer cell lines. -- Abstract: Vacuole membrane protein 1 (VMP1) is an autophagy-related protein and identified as a key regulator of autophagy in recent years. In pancreatic cell lines, VMP1-dependent autophagy has been linked to positive regulation of apoptosis. However, there are no published reports on the role of VMP1 in autophagy and apoptosis in colorectal cancers. Therefore, to address this gap of knowledge, we decided to interrogate regulation of autophagy and apoptosis by VMP1. We have studied the induction of autophagy by starvation and rapamycin treatment in colorectal cell lines using electron microscopy, immunofluorescence, and immunoblotting. We found that starvation-induced autophagy correlated with an increase in VMP1 expression, that VMP1 interacted with BECLIN1, and that siRNA mediated down-regulation of VMP1-reduced autophagy. Next, we examined the relationship between VMP1-dependent autophagy and apoptosis and found that VMP1 down-regulation sensitizes cells to apoptosis and that agents that induce apoptosis down-regulate VMP1. In conclusion, similar to its reported role in other cell types, VMP1 is an important regulator of autophagy in colorectal cell lines. However, in contrast to its role in pancreatic cell lines, in colorectal cancer cells, VMP1-dependent autophagy appears to be pro-survival rather than pro-cell death.

  17. Coherent control of multiphoton dynamics and high-order-harmonic generation driven by two frequency-comb fields with a relative envelope delay

    Science.gov (United States)

    Zhao, Di; Jiang, Chen-Wei; Li, Fu-li

    2016-07-01

    We present a theoretical investigation of the coherent control of multiphoton dynamics and a high-order-harmonic generation (HHG) process driven by two frequency-comb fields, via the interference of multiphoton transition paths by tuning the relative envelope delay between fields. The many-mode Floquet theorem is employed to provide a nonperturbative and exact treatment of the interaction between a quantum system and frequency-comb laser fields. The case of two frequency-comb fields with the same repetition frequency and the carrier frequencies of fundamental and second harmonics, respectively, is considered. Due to the coupling of the second harmonic controlling the frequency-comb laser field, multiphoton transitions involving both fundamental- and second-harmonic photons occur. Different multiphoton transition paths can be superpositioned when the matching condition for carrier-envelope-phase shifts is satisfied, offering the possibility of coherent control of HHG power spectra via the interference of paths by tuning the relative envelope delay between fields. The calculated HHG power spectra present both sub-cycle oscillation and multi-cycle modulation behavior when the relative envelope delay is varied. It is also found that, under the condition of multiphoton resonance, the HHG power spectra can be further enhanced by about 10 times via the interference of multiphoton transition paths by tuning the relative envelope delay.

  18. Comparative study of time-dependent effects of 4 and 8 Hz mechanical vibration at infrasound frequency on E. coli K-12 cells proliferation.

    Science.gov (United States)

    Martirosyan, Varsik; Ayrapetyan, Sinerik

    2015-01-01

    The aim of the present work is to study the time-dependent effects of mechanical vibration (MV) at infrasound (IS) frequency at 4 and 8 Hz on E. coli K-12 growth by investigating the cell proliferation, using radioactive [(3)H]-thymidine assay. In our previous work it was suggested that the aqua medium can serve as a target through which the biological effect of MV on microbes could be realized. At the same time it was shown that microbes have mechanosensors on the surface of the cells and can sense small changes of the external environment. The obtained results were shown that the time-dependent effects of MV at 4 and 8 Hz frequency could either stimulate or inhibit the growth of microbes depending from exposure time. It more particularly, the invention relates to a method for controlling biological functions through the application of mechanical vibration, thus making it possible to artificially control the functions of bacterial cells, which will allow us to develop method that can be used in agriculture, industry, medicine, biotechnology to control microbial growth. PMID:24725172

  19. [Frequency of sickle-cell anemia in the population of "Cuatro Bocas," Parroquia Ricaurte, Mara municipality, Zulia state, Venezuela].

    Science.gov (United States)

    Torres-Guerra, E; Torres-Guerra, T; Valbuena, G; Arteaga Vizcaíno, M; Soto, L

    1993-01-01

    Isla de Toas is an island on the north of the Maracaibo Lake, it is known in the scientific community, for the high frequency of sickle cell disease, in a population with caucasoid phenotype. The purpose of the present work was to determine the frequency of sickle cell anemia in the population of Cuatro Bocas, situated 35 km from the southwest of Isla de Toas. The town is the center of confluence of a rural population constituted mainly of farmers. The sample consisted of 870 persons of both sexes, aged from 8 months to 66 years. The presence of the sickling phenomenon was determined in all the individuals, and hemoglobin electrophoresis in agarose was performed in all the positive samples. The following results were obtained: fifty-six cases (6.4%), showed drepanocytic changes, and forty-six of them were haemoglobin A/S, 8 were S/S and 2 were S/C. The higher frequency of hemoglobin S was in adolescents and adults. The family backgrounds suggest an insular origin of the sickle cell gene. About 75% of the affected population was ignorant of this condition. The hemoglobin values were lower in the individuals with the sickle cell disease (p Iron deficiency in adolescents was suspected because or their low hemoglobin values. The results indicate that the sickle cell gen is expanding to the nearest communities of the Mara county. It is important to consider that the findings of the present work should serve as an alert to the Public Health authorities, and that education of the population is important in order to prevent the spreading of the disease.

  20. Complex Systems Theory to understand extremely low frequency magnetic fields interaction with immune cells

    Science.gov (United States)

    Vázquez-Coutiño, G. A.; Serrano-Luna, G.; Cañedo-Dorantes, L.; Godina-Nava, J. J.; Rodríguez-Segura, M. A.

    2003-09-01

    Well-documented studies about the interaction of extremely low frequency electromagnetic fields (ELF) with lymphocytes provide elements for the development of non-linear theoretical models. The Eichwald-Kaiser model of calcium oscillations was tested with a rectified cosine function at a frequency of 120 Hz. A change in dynamical behavior of calcium oscillations, from periodic in the normal case (without perturbation, what corresponds to a limit cycle) to the existence of very small micro-oscillations and a strange attractor in the perturbed case was found. It is concluded that the ELF configuration used in this model, alters the dynamical behavior of calcium oscillations in lymphocytes.

  1. High-Frequency Link Inverter for Fuel Cells Based on Multiple-Carrier PWM

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    HIGH-FREQUENCY (I-IF) ac link inverter topologies, with or without soft switching, have important practical advantages compared to more conventional dc link inverters in terms of isolation, size of magnetics, and other properties. It is possible to obtain these basic advantages directly in a conventional PWM inverter with trans former-coupled output, but only if the transformer can handle the low modulating frequency. HF link topologies have not been common for medium power (1 to 20kW), largely because of the number of power stages and control complexity.

  2. Reproducibility and Relative Validity of a Short Food Frequency Questionnaire in 9–10 Year-Old Children

    Directory of Open Access Journals (Sweden)

    Pouya Saeedi

    2016-05-01

    Full Text Available The aim of this study was to assess the reproducibility and validity of a non-quantitative 28-item food frequency questionnaire (FFQ. Children aged 9–10 years (n = 50 from three schools in Dunedin, New Zealand, completed the FFQ twice and a four-day estimated food diary (4DEFD over a two-week period. Intraclass correlation coefficients (ICC and Spearman’s correlation coefficients (SCC were used to determine reproducibility and validity of the FFQ, respectively. Weekly intakes were estimated for each food item and aggregated into 23 food items/groups. More than half of the food items/groups (52.2% had an ICC ≥0.5. The median SCC between FFQ administrations was 0.66 (ranging from 0.40 for processed meat to 0.82 for sweets and non-dairy drinks. Cross-classification analysis between the first FFQ and 4DEFD for ranking participants into thirds showed that breakfast cereals had the highest agreement (54.0% and pasta the lowest (34.0%. In validity analyses, 70% of food items/groups had a SCC ≥0.3. Results indicate that the FFQ is a useful tool for ranking children according to food items/groups intake. The low respondent burden and relative simplicity of the FFQ makes it suitable for use in large cohort studies of 9–10 year-old children in New Zealand.

  3. Observation of radiation-specific damage in human cells exposed to depleted uranium: dicentric frequency and neoplastic transformation as endpoints

    International Nuclear Information System (INIS)

    Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Published data from our laboratory have demonstrated that DU exposure in vitro to immortalised human osteoblast cells (HOS) is both neoplastically transforming and genotoxic. DU possesses both a radiological (alpha-particle) and chemical (metal) component. Since DU has a low specific activity in comparison to natural uranium, it is not considered to be a significant radiological hazard. The potential contribution of radiation to DU-induced biological effects is unknown and the involvement of radiation in DU-induced biological effects could have significant implication for current risk estimates for internalised DU exposure. Two approaches were used to address this question. The frequency of dicentrics was measured in HOS cells following DU exposure in vitro. Data demonstrated that DU exposure (50 μM, 24h) induced a significant elevation in dicentric frequency in vitro in contrast to incubation with the heavy metals, nickel and tungsten which did not increase dicentric frequency above background levels. Using the same concentration (50 μM) of three uranyl nitrate compounds that have different uranium isotopic concentrations and therefore, different specific activities, the effect on neoplastic transformation in vitro was examined. HOS cells were exposed to one of three-uranyl nitrate compounds (238U-uranyl nitrate, specific activity 0.33 μCi.g-1: DU-uranyl nitrate, specific activity 0.44 μCi.g-1: and 235U-uranyl nitrate, specific activity 2.2 μCi.g-1) delivered at a concentration of 50 μM for 24 h. Results showed, at equal uranium concentration, there was a specific activity dependent increase in neoplastic transformation frequency. Taken together these data suggest that radiation can play a role in DU-induced biological effects in vitro. (author)

  4. Monitoring cell-cycle-related viscoelasticity by a quartz crystal microbalance

    Science.gov (United States)

    Alessandrini, A.; Croce, M. A.; Tiozzo, R.; Facci, P.

    2006-02-01

    We have monitored viscoelasticity variation of a cell population during the cell cycle by a Quartz Crystal Microbalance (QCM). Balb 3T3 fibroblasts were synchronized in the G0/G1 phase and seeded in a QCM chamber placed in a cell incubator. After cell sedimentation, the frequency signal was characterized by an amplitude modulation attributed to the viscoelasticity variation of the cells proliferating in phase. A control experiment with nonsynchronized cells showed a similar signal trend, but without significant modulation. Interestingly, the system resulted also to perform as a device sensitive to the effect of drugs affecting the cell cycle, such as colchicine.

  5. Frequency of musculoskeleton health problems and its relation with demographic variables among cherat coal miners district nowshera khyber pukhtunkhwa pakistan

    International Nuclear Information System (INIS)

    The objective was to determine the frequency of musculo-skeleton health problems among the coal miners and to assess the relation of musculo-skeleton with various demographic variables among cherat coal miners of District Nowshera Khyber Pukhtunkhwa Pakistan. Materials and Methods: A cross-sectional study design was conducted between July and December 2014 at the cherat coal mines of District Nowshera. A sample size of 400 was selected through cluster sampling technique, in which the study area was divided into four clusters and then from each cluster 40% coal miners were selected based on simple random technique. There are approximately 80-90 Cherat coal mines in which around 1000 of coal miners are working. Coal miner's having more than one year of coal mining job were included in the study while those with less than one year or having any pathological problems were excluded from the study population. Field visits were conducted to collect relevant data from the study areas. The structured pretested questionnaire was used to collect data regarding history of musculo-skeleton problems and was evaluated with the selected demographic variables like age, duration of coal mining job, job satisfaction, and previous history of mine injuries. Results: Our study results showed that approximately 61% of coal miners had history of musculo-skeleton problems. Among those coal miners who gave history of musculo-skeleton problems, 76.64% were due to lack of training, 24.59% to early 1-4 years of coal mining job, 60.23% to less than 30 years of coal miner's age, 75.00% to unsatisfied with job, 83.19% to poor/bad knowledge of mine safety measures; 58.87% for not using personnel protective measures; and 67.62% to positive smoking history while the remaining 32.38 were among non-smokers. Conclusion: The frequency of occupational musculo-skeleton problems among coal miners 61% more and had strong relationship with age, duration of coal mining job, smoking behavior, job satisfaction

  6. Adenosine A(2A receptor up-regulates retinal wave frequency via starburst amacrine cells in the developing rat retina.

    Directory of Open Access Journals (Sweden)

    Pin-Chien Huang

    Full Text Available BACKGROUND: Developing retinas display retinal waves, the patterned spontaneous activity essential for circuit refinement. During the first postnatal week in rodents, retinal waves are mediated by synaptic transmission between starburst amacrine cells (SACs and retinal ganglion cells (RGCs. The neuromodulator adenosine is essential for the generation of retinal waves. However, the cellular basis underlying adenosine's regulation of retinal waves remains elusive. Here, we investigated whether and how the adenosine A(2A receptor (A(2AR regulates retinal waves and whether A(2AR regulation of retinal waves acts via presynaptic SACs. METHODOLOGY/PRINCIPAL FINDINGS: We showed that A(2AR was expressed in the inner plexiform layer and ganglion cell layer of the developing rat retina. Knockdown of A(2AR decreased the frequency of spontaneous Ca²⁺ transients, suggesting that endogenous A(2AR may up-regulate wave frequency. To investigate whether A(2AR acts via presynaptic SACs, we targeted gene expression to SACs by the metabotropic glutamate receptor type II promoter. Ca²⁺ transient frequency was increased by expressing wild-type A(2AR (A2AR-WT in SACs, suggesting that A(2AR may up-regulate retinal waves via presynaptic SACs. Subsequent patch-clamp recordings on RGCs revealed that presynaptic A(2AR-WT increased the frequency of wave-associated postsynaptic currents (PSCs or depolarizations compared to the control, without changing the RGC's excitability, membrane potentials, or PSC charge. These findings suggest that presynaptic A(2AR may not affect the membrane properties of postsynaptic RGCs. In contrast, by expressing the C-terminal truncated A(2AR mutant (A(2AR-ΔC in SACs, the wave frequency was reduced compared to the A(2AR-WT, but was similar to the control, suggesting that the full-length A(2AR in SACs is required for A(2AR up-regulation of retinal waves. CONCLUSIONS/SIGNIFICANCE: A(2AR up-regulates the frequency of retinal waves via

  7. Very high frequency plasma deposited amorphous/nanocrystalline silicon tandem solar cells on flexible substrates

    OpenAIRE

    Liu, Y

    2010-01-01

    The work in this thesis is to develop high quality intrinsic layers (especially nc-Si:H) for micromorph silicon tandem solar cells/modules on plastic substrates following the substrate transfer method or knows as the Helianthos procedure. Two objectives are covered in this thesis: (1) preliminary work on trial and optimization of single junction and tandem cells on glass substrate, (2) silicon film depositions on Al foil, and afterwards the characterization and development of these cells/modu...

  8. Cu(In,Ga)Se2 and Related Solar Cells

    Science.gov (United States)

    Rau, Uwe; Schock, Hans W.

    2015-10-01

    The following sections are included: * Introduction * Material properties * Cell and module technology * Device physics * Wide-gap chalcopyrites * Kesterite (CZTS) solar cells * Conclusions * References

  9. Regulation of follicular B cell differentiation by the related E26 transformation-specific transcription factors PU.1, Spi-B, and Spi-C.

    Science.gov (United States)

    DeKoter, Rodney P; Geadah, Marc; Khoosal, Sonam; Xu, Li S; Thillainadesan, Gobi; Torchia, Joseph; Chin, Shu Shien; Garrett-Sinha, Lee Ann

    2010-12-15

    Splenic B-2 cells can be divided into two major subsets: follicular (FO) and marginal zone (MZ) B cells. FO and MZ B cells are generated from immature transitional B cells. Few transcription factors have been identified that regulate FO B cell differentiation. The highly related proteins PU.1, Spi-B, and Spi-C are transcription factors of the E26-transformation-specific family and are important for B cell differentiation and function. To determine whether these proteins play a role in the differentiation of FO B cells, we performed a detailed analysis of splenic B cells in mice with inactivating mutations in the genes encoding PU.1 (Sfpi1) or Spi-B (Spib). Sfpi1(+/-) Spib(-/-) (PUB) mice had a 9-fold reduction in the frequency of CD23(+) FO B cells compared with that of wild-type mice. In contrast, PUB mice had a 2-fold increase in the frequency of MZ B cells that was confirmed by immunofluorescence staining. Expression of Spi-C in Eμ-Spi-C transgenic PUB mice partially rescued frequencies of CD23(+) B cells. Gene expression analysis, in vitro reporter assays, and chromatin immunoprecipitation experiments showed that transcription of the Fcer2a gene encoding CD23 is activated by PU.1, Spi-B, and Spi-C. These results demonstrate that FO B cell differentiation is regulated by the E26-transformation-specific transcription factors PU.1, Spi-B, and Spi-C.

  10. Radio-frequency-magnetron-sputtered CdS/CdTe solar cells on soda-lime glass

    Energy Technology Data Exchange (ETDEWEB)

    Shao, M.; Fischer, A.; Grecu, D.; Jayamaha, U.; Bykov, E.; Contreras-Puente, G.; Bohn, R.G.; Compaan, A.D. [Department of Physics and Astronomy and Center for Materials Science and Engineering, The University of Toledo, Toledo, Ohio 43606 (United States)

    1996-11-01

    We report the fabrication of an 11.6{percent} efficient, polycrystalline thin-film CdS/CdTe solar cell in which both semiconductor layers were deposited by planar-magnetron-radio-frequency sputtering at 380{degree}C on commercially available soda-lime float-glass substrates coated with SnO{sub 2}:F. We show that the magnetron magnetic field is critical to obtaining high cell efficiency. Much stronger photoluminescence and higher electrical conductivity are found in films and cells grown with unbalanced-field magnetrons. The magnetic field dependence is interpreted as arising from the enhanced electron and ion bombardment of the film growth interface when unbalanced magnetrons are used. {copyright} {ital 1996 American Institute of Physics.}

  11. The position of DNA cleavage by TALENs and cell synchronization influences the frequency of gene editing directed by single-stranded oligonucleotides.

    Directory of Open Access Journals (Sweden)

    Natalia Rivera-Torres

    Full Text Available With recent technological advances that enable DNA cleavage at specific sites in the human genome, it may now be possible to reverse inborn errors, thereby correcting a mutation, at levels that could have an impact in a clinical setting. We have been developing gene editing, using single-stranded DNA oligonucleotides (ssODNs, as a tool to direct site specific single base changes. Successful application of this technique has been demonstrated in many systems ranging from bacteria to human (ES and somatic cells. While the frequency of gene editing can vary widely, it is often at a level that does not enable clinical application. As such, a number of stimulatory factors such as double-stranded breaks are known to elevate the frequency significantly. The majority of these results have been discovered using a validated HCT116 mammalian cell model system where credible genetic and biochemical readouts are available. Here, we couple TAL-Effector Nucleases (TALENs that execute specific ds DNA breaks with ssODNs, designed specifically to repair a missense mutation, in an integrated single copy eGFP gene. We find that proximal cleavage, relative to the mutant base, is key for enabling high frequencies of editing. A directionality of correction is also observed with TALEN activity upstream from the target base being more effective in promoting gene editing than activity downstream. We also find that cells progressing through S phase are more amenable to combinatorial gene editing activity. Thus, we identify novel aspects of gene editing that will help in the design of more effective protocols for genome modification and gene therapy in natural genes.

  12. lck-Driven Cre Expression Alters T Cell Development in the Thymus and the Frequencies and Functions of Peripheral T Cell Subsets.

    Science.gov (United States)

    Carow, Berit; Gao, Yu; Coquet, Jonathan; Reilly, Marie; Rottenberg, Martin E

    2016-09-15

    Conditional gene targeting using the bacteriophage-derived Cre recombinase is widely applied for functional gene studies in mice. Mice transgenic for Cre under the control of the lck gene promoter are used to study the role of loxP-targeted genes in T cell development and function. In this article, we show a striking 65% reduction in cellularity, preferential development of γδ versus αβ T cells, and increased expression of IL-7R in the thymus of mice expressing Cre under the proximal lck promoter (lck-cre(+) mice). The transition from CD4/CD8 double-negative to double-positive cells was blocked, and lck-cre(+) double-positive cells were more prone to apoptosis and showed higher levels of Cre expression. Importantly, numbers of naive T cells were reduced in spleens and lymph nodes of lck-cre(+) mice. In contrast, frequencies of γδ T cells, CD44(+)CD62L(-) effector T cells, and Foxp3(+) regulatory T cells were elevated, as was the frequency of IFN-γ-secreting CD4(+) and CD8(+) T cells. A literature survey of 332 articles that used lck-cre(+) mice for deletion of floxed genes indicated that results are statistically influenced by the control used (lck-cre(+) or lck-cre(-)), more frequently resembling the lck-cre(+) phenotype described in this article if lck-cre(-) controls were used. Altogether, care should be taken when interpreting published results and to properly control targeted gene deletions using the lck-cre(+) strain. PMID:27503210

  13. A thorough analysis of the short- and mid-term activity-related variations in the solar acoustic frequencies

    CERN Document Server

    Santos, A R G; Avelino, P P; Chaplin, W J; Campante, T L

    2016-01-01

    The frequencies of the solar acoustic oscillations vary over the activity cycle. The variations in other activity proxies are found to be well correlated with the variations in the acoustic frequencies. However, each proxy has a slightly different time behaviour. Our goal is to characterize the differences between the time behaviour of the frequency shifts and of two other activity proxies, namely, the area covered by sunspots and the 10.7cm flux. We define a new observable that is particularly sensitive to the short-term frequency variations. We then compare the observable when computed from model frequency shifts and from observed frequency shifts obtained with the Global Oscillation Network Group (GONG) for cycle 23. Our analysis shows that on the shortest time-scales the variations in the frequency shifts seen in the GONG observations are strongly correlated with the variations in the area covered by sunspots. However, a significant loss of correlation is still found. We verify that the times when the fre...

  14. Discrepancy of B cell frequency between periphery and spleen after rituximab treatment in ABO-incompatible liver transplantation.

    Science.gov (United States)

    Iso, Yukihiro; Sawada, Tokihiko; Kita, Junji; Shiraki, Takayuki; Sakuraoka, Yuki; Kato, Masato; Shimoda, Mitsugi; Kubota, Keiichi

    2013-10-01

    ABO-incompatible living-donor liver transplantation (ABO-LDLT) is generally more difficult to perform than ABO-incompatible kidney transplantation. Despite introduction of rituximab, ABO-LDLT in non-responders is a still difficult issue. A 23-year-old woman with primary sclerosing cholangitis underwent LDLT. The recipient's blood type was 0(+) and the donor's was B(+). Rituximab was infused twice on preoperative day (POD) 14 and 7. Plasma exchange (PE) was performed on PODs 5, 3, 2, and 1. However, repeated PE failed to decrease the anti-B antibody titer. On the other hand, preoperative esophagogastroscopy revealed esophageal varices with red color sign. Therefore, simultaneous liver transplantation and Hassab operation were performed. The donor left lobe of the liver was orthotopically transplanted into the recipient following Hassab operation. Flow cytometry on the day of surgery showed that the frequencies of B cells (CD20+) and memory B cells (CD20+/CD27+) in the peripheral blood were 0.9% and 0.3%, respectively; flow cytometry of cells recovered from the spleen revealed that the frequencies of B cells and memory B cells were 2.5% and 2.4%, respectively. Acute cellular rejection occurred on POD 15, and was treated by steroid pulse therapy, leading to a decrease in the anti-B antibody titer. The liver was functioning well on POD 390 (AST 19, ALT 34). In non-responders to ABO-LDLT, anti-donor blood type antibody-producing cells remains in the spleen after the conventional preoperative regimen. Splenectomy is an option for ABO-LDLT non-responders.

  15. Microelectrical Impedance Spectroscopy for the Differentiation between Normal and Cancerous Human Urothelial Cell Lines: Real-Time Electrical Impedance Measurement at an Optimal Frequency

    Directory of Open Access Journals (Sweden)

    Yangkyu Park

    2016-01-01

    Full Text Available Purpose. To distinguish between normal (SV-HUC-1 and cancerous (TCCSUP human urothelial cell lines using microelectrical impedance spectroscopy (μEIS. Materials and Methods. Two types of μEIS devices were designed and used in combination to measure the impedance of SV-HUC-1 and TCCSUP cells flowing through the channels of the devices. The first device (μEIS-OF was designed to determine the optimal frequency at which the impedance of two cell lines is most distinguishable. The μEIS-OF trapped the flowing cells and measured their impedance at a frequency ranging from 5 kHz to 1 MHz. The second device (μEIS-RT was designed for real-time impedance measurement of the cells at the optimal frequency. The impedance was measured instantaneously as the cells passed the sensing electrodes of μEIS-RT. Results. The optimal frequency, which maximized the average difference of the amplitude and phase angle between the two cell lines (p<0.001, was determined to be 119 kHz. The real-time impedance of the cell lines was measured at 119 kHz; the two cell lines differed significantly in terms of amplitude and phase angle (p<0.001. Conclusion. The μEIS-RT can discriminate SV-HUC-1 and TCCSUP cells by measuring the impedance at the optimal frequency determined by the μEIS-OF.

  16. Antiviral Treatment Alters the Frequency of Activating and Inhibitory Receptor-Expressing Natural Killer Cells in Chronic Hepatitis B Virus Infected Patients

    Directory of Open Access Journals (Sweden)

    Juan Lv

    2012-01-01

    Full Text Available Natural killer (NK cells play a critical role in innate antiviral immunity, but little is known about the impact of antiviral therapy on the frequency of NK cell subsets. To this aim, we performed this longitudinal study to examine the dynamic changes of the frequency of different subsets of NK cells in CHB patients after initiation of tenofovir or adefovir therapy. We found that NK cell numbers and subset distribution differ between CHB patients and normal subjects; furthermore, the association was found between ALT level and CD158b+ NK cell in HBV patients. In tenofovir group, the frequency of NK cells increased during the treatment accompanied by downregulated expression of NKG2A and KIR2DL3. In adefovir group, NK cell numbers did not differ during the treatment, but also accompanied by downregulated expression of NKG2A and KIR2DL3. Our results demonstrate that treatment with tenofovir leads to viral load reduction, and correlated with NK cell frequencies in peripheral blood of chronic hepatitis B virus infection. In addition, treatments with both tenofovir and adefovir in chronic HBV infected patients induce a decrease of the frequency of inhibitory receptor+ NK cells, which may account for the partial restoration of the function of NK cells in peripheral blood following treatment.

  17. Microelectrical Impedance Spectroscopy for the Differentiation between Normal and Cancerous Human Urothelial Cell Lines: Real-Time Electrical Impedance Measurement at an Optimal Frequency

    Science.gov (United States)

    Park, Yangkyu; Kim, Hyeon Woo; Yun, Joho; Seo, Seungwan; Park, Chang-Ju; Lee, Jeong Zoo; Lee, Jong-Hyun

    2016-01-01

    Purpose. To distinguish between normal (SV-HUC-1) and cancerous (TCCSUP) human urothelial cell lines using microelectrical impedance spectroscopy (μEIS). Materials and Methods. Two types of μEIS devices were designed and used in combination to measure the impedance of SV-HUC-1 and TCCSUP cells flowing through the channels of the devices. The first device (μEIS-OF) was designed to determine the optimal frequency at which the impedance of two cell lines is most distinguishable. The μEIS-OF trapped the flowing cells and measured their impedance at a frequency ranging from 5 kHz to 1 MHz. The second device (μEIS-RT) was designed for real-time impedance measurement of the cells at the optimal frequency. The impedance was measured instantaneously as the cells passed the sensing electrodes of μEIS-RT. Results. The optimal frequency, which maximized the average difference of the amplitude and phase angle between the two cell lines (p < 0.001), was determined to be 119 kHz. The real-time impedance of the cell lines was measured at 119 kHz; the two cell lines differed significantly in terms of amplitude and phase angle (p < 0.001). Conclusion. The μEIS-RT can discriminate SV-HUC-1 and TCCSUP cells by measuring the impedance at the optimal frequency determined by the μEIS-OF. PMID:26998490

  18. Whole-genome gene expression modifications associated with nitrosamine exposure and micronucleus frequency in human blood cells

    DEFF Research Database (Denmark)

    Hebels, Dennie G A J; Jennen, Danyel G J; van Herwijnen, Marcel H M;

    2011-01-01

    N-nitroso compounds (NOCs) are suspected human carcinogens and relevant in human exposure. NOCs also induce micronuclei (MN) formation in vivo. Since lymphocytic MN represent a validated biomarker of human cancer risk, establishing a link between NOC exposure and MN frequency in humans...... association between MN frequency and urinary NOCs (r = 0.41, P = 0.025) and identified modifications in among others cytoskeleton remodeling, cell cycle, apoptosis and survival, signal transduction, immune response, G-protein signaling and development pathways, which indicate a response to NOC......-induced genotoxicity. Moreover, we established a network of genes, the most important ones of which include FBXW7, BUB3, Caspase 2, Caspase 8, SMAD3, Huntingtin and MGMT, which are involved in processes relevant in carcinogenesis. The modified genetic processes and genes found in this study may be of interest...

  19. Geographical changes in relative frequency of inversions in chromosome III of Drosophila pseudoobscura among natural populations from Mexico

    Directory of Open Access Journals (Sweden)

    Salceda Víctor M.

    2009-01-01

    Full Text Available Chromosomal polymorphism in natural populations of Drosophila pseudoobscura have been broadly studied in the USA but scarcely in Mexico where only about 60 localities have been analyzed. Differences among both regions are notorious with respect to their chromosomal constitution. Northern populations, those of USA, have as representative inversions the sequences ST, AR and CH contrasting with those in Southern populations (Mexico in which prevail the gene arrangements TL, CU and SC. Assuming as a probable mechanism that has allowed these substitutions the flow generated by the presence of a North - South clines, we took as a goal find out if such clines really exist. With that objective in mind we studied 29 populations of this species distributed along four North - South transects. Specimens of D. pseudoobscura caught by attracting them with fermenting bananas were carried to the laboratory where from each female an isofemale line was established. When their offspring appeared a single larva from each isofemale was taken, its salivary glands extracted and stained with a solution of lacto-aceto- orcein, by these means the polytene chromosomes were obtained. On these chromosomes we identified, for each larva, the inversion (s carried in the third chromosome, in such a way 3439 third chromosomes were analyzed. Among the 29 localities we identified 17 different inversions but the number of them varied from population to population from three to eleven. Relative frequencies of each inversion at every location were calculated and with them for each transect the presence or absence of clines was determined. Among each transect the existence of clines was observed only between two or three near by populations, but we were not able to find a clear manifestation of the presence of clines along a complete transect. Our results at this respect are similar to those previously reported for USA populations. A mechanism that explains North - South substitutions

  20. Diastolic time – frequency relation in the stress echo lab: filling timing and flow at different heart rates

    Directory of Open Access Journals (Sweden)

    Faita Francesco

    2008-04-01

    Full Text Available Abstract A cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been recently validated. Second heart sound can be simultaneously recorded in order to quantify both systole and diastole duration. Aims 1- To assess the feasibility and extra-value of operator-independent, force sensor-based, diastolic time recording during stress. Methods We enrolled 161 patients referred for stress echocardiography (exercise 115, dipyridamole 40, pacing 6 patients. The sensor was fastened in the precordial region by a standard ECG electrode. The acceleration signal was converted into digital and recorded together with ECG signal. Both systolic and diastolic times were acquired continuously during stress and were displayed by plotting times vs. heart rate. Diastolic filling rate was calculated as echo-measured mitral filling volume/sensor-monitored diastolic time. Results Diastolic time decreased during stress more markedly than systolic time. At peak stress 62 of the 161 pts showed reversal of the systolic/diastolic ratio with the duration of systole longer than diastole. In the exercise group, at 100 bpm HR, systolic/diastolic time ratio was lower in the 17 controls (0.74 ± 0.12 than in patients (0.86 ± 0.10, p Diastolic filling rate increased from 101 ± 36 (rest to 219 ± 92 ml/m2* s-1 at peak stress (p Conclusion Cardiological systolic and diastolic duration can be monitored during stress by using an acceleration force sensor. Simultaneous calculation of stroke volume allows monitoring diastolic filling rate. Stress-induced "systolic-diastolic mismatch" can be easily quantified and is associated to several cardiac diseases, possibly expanding the spectrum of information obtainable during stress.

  1. Transformation of frequency-magnitude relation prior to large events in the model of block structure dynamics

    Directory of Open Access Journals (Sweden)

    A. Soloviev

    2008-02-01

    Full Text Available The b-value change in the frequency-magnitude (FM distribution for a synthetic earthquake catalogue obtained by means of the model of block structure dynamics has been studied. The catalogue is divided into time periods preceding strong earthquakes and time periods that do not precede strong earthquakes. The separate analysis of these periods shows that the b-value is smaller before strong earthquakes. The similar phenomenon has been found also for the observed seismicity of the Southern California. The model of block structure dynamics represents a seismic region as a system of perfectly rigid blocks divided by infinitely thin plane faults. The blocks interact between themselves and with the underlying medium. The system of blocks moves as a consequence of prescribed motion of the boundary blocks and of the underlying medium. As the blocks are perfectly rigid, all deformation takes place in the fault zones and at the block base in contact with the underlying medium. Relative block displacements take place along the fault zones. Block motion is defined so that the system is in a quasistatic equilibrium state. The interaction of blocks along the fault zones is viscous-elastic ("normal state" while the ratio of the stress to the pressure remains below a certain strength level. When the critical level is exceeded in some part of a fault zone, a stress-drop ("failure" occurs (in accordance with the dry friction model, possibly causing failure in other parts of the fault zones. These failures produce earthquakes. Immediately after the earthquake and for some time after, the affected parts of the fault zones are in a state of creep. This state differs from the normal state because of a faster growth of inelastic displacements, lasting until the stress falls below some other level. This numerical simulation gives rise a synthetic earthquake catalogue.

  2. Mucus transport mechanisms in relation to the effect of high frequency chest compression (HFCC) on mucus clearance.

    Science.gov (United States)

    Hansen, L G; Warwick, W J; Hansen, K L

    1994-02-01

    High frequency chest compression (HFCC) appears promising as a form of chest physiotherapy. Studies published by several clinical centers support its efficacy, and further clinical data are expected to become available.

  3. A broadband chip-scale optical frequency synthesizer at 2.7 × 10−16 relative uncertainty

    OpenAIRE

    Huang, Shu-Wei; Yang, Jinghui; Yu, Mingbin; McGuyer, Bart H.; Kwong, Dim-Lee; Zelevinsky, Tanya; Wong, Chee Wei

    2016-01-01

    Optical frequency combs—coherent light sources that connect optical frequencies with microwave oscillations—have become the enabling tool for precision spectroscopy, optical clockwork, and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but Kerr nonlinear dynamics in high-Q solid-state microresonators has recently demonstrated promising features as alternative platforms. The advance not only fosters studies of chip-scale ...

  4. Mouse strain-dependent changes in frequency and proliferation of hematopoietic stem cells during aging : Correlation between lifespan and cycling activity

    NARCIS (Netherlands)

    deHaan, G; Nijhof, W; VanZant, G

    1997-01-01

    We have quantified the frequency and proliferation of five subsets of primitive hematopoietic cells, using the cobblestone area forming cell (CAFC) assay, in marrow of five strains of mice with lifespans ranging from about 500 to 800 days. Stem cell characteristics were determined in young (6 weeks)

  5. Dielectric spectroscopy of normal and malignant human lung cells at ultra-high frequencies

    International Nuclear Information System (INIS)

    Microwave techniques for biomedical applications aimed at cancer treatment or diagnosis, either by imaging or spectroscopy, are promising. Their use relies on knowledge of the dielectric properties of tissues, especially on a detectable difference between malignant and normal tissues. As most studies investigated the dielectric properties of ex vivo tissues, there is a need for better biophysical understanding of human tissues in their living state. As an essential component of tissues, cells represent valuable objects of analysis. The approach developed in this study is an investigation at cell level. Its aim was to compare human lung normal and malignant cells by dielectric spectroscopy in the beginning of the microwave range, where such information is of substantial biomedical importance. These cells were embedded in small and low-conductivity agarose hydrogels and laid on an open-ended coaxial probe connected to a vector network analyser operated from 200 MHz to 2 GHz. The comparison between normal and malignant cells was drawn using the variation of measured dielectric properties and fitting the measurements using the Maxwell-Wagner equation. Both methods revealed slight differences between the two cell lines, which were statistically significant regarding conductivities of composite gels and cells.

  6. Dielectric spectroscopy of normal and malignant human lung cells at ultra-high frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Egot-Lemaire, S; Pijanka, J; Sule-Suso, J; Semenov, S [Keele University Medical School, Institute for Science and Technology in Medicine, Stoke-on-Trent (United Kingdom)], E-mail: stephegle@msn.com, E-mail: j.k.pijanka@istm.keele.ac.uk, E-mail: jsule@dial.pipex.com, E-mail: s.semenov@pmed.keele.ac.uk

    2009-04-21

    Microwave techniques for biomedical applications aimed at cancer treatment or diagnosis, either by imaging or spectroscopy, are promising. Their use relies on knowledge of the dielectric properties of tissues, especially on a detectable difference between malignant and normal tissues. As most studies investigated the dielectric properties of ex vivo tissues, there is a need for better biophysical understanding of human tissues in their living state. As an essential component of tissues, cells represent valuable objects of analysis. The approach developed in this study is an investigation at cell level. Its aim was to compare human lung normal and malignant cells by dielectric spectroscopy in the beginning of the microwave range, where such information is of substantial biomedical importance. These cells were embedded in small and low-conductivity agarose hydrogels and laid on an open-ended coaxial probe connected to a vector network analyser operated from 200 MHz to 2 GHz. The comparison between normal and malignant cells was drawn using the variation of measured dielectric properties and fitting the measurements using the Maxwell-Wagner equation. Both methods revealed slight differences between the two cell lines, which were statistically significant regarding conductivities of composite gels and cells.

  7. Broncho-Vaxom attenuates allergic airway inflammation by restoring GSK3β-related T regulatory cell insufficiency.

    Directory of Open Access Journals (Sweden)

    Ran Fu

    Full Text Available BACKGROUND: Oral administration of bacterial extracts (eg, Broncho-Vaxom (BV has been proposed to attenuate asthma through modulating Treg cells. However, the underlying mechanism has not been fully characterized. This study sought to assess the effects of oral administration of BV on GSK-3β expression and Treg cells in ovalbumin (OVA-induced asthmatic mice models. METHOD: Asthmatic mice models were established with OVA challenge and treated with oral administration of BV. Next, infiltration of inflammatory cells including eosinophil and neutrophils, mucous metaplasia, levels of Th1/Th2/Treg-typed cytokines and expression of GSK3β and Foxp3 were examined in asthmatic mice models by histological analysis, Bio-Plex and western blot, respectively. Moreover, the frequencies of Treg cells were evaluated in cultured splenocytes by flow cytometry in the presence of BV or GSK3β siRNA interference. RESULTS: We found significant decrease of infiltrated inflammatory cells in bronchoalveolar lavage fluid (BALF in asthmatic mice models after oral administration of BV. Oral administration of BV was shown to significantly suppress mucus metaplasia, Th2-typed cytokine levels and GSK3β expression while increasing Foxp3 production in asthmatic mice models. Moreover, BV significantly enhanced GSK3β-related expansion of Treg cells in cultured spleen cells in vitro. CONCLUSION: Our findings provide evidence that oral administration of BV is capable of attenuating airway inflammation in asthmatic mice models, which may be associated with GSK3β-related expansion of Treg cells.

  8. Relative validity and reproducibility of a food frequency questionnaire to assess dietary fiber intake in Danish adults

    Directory of Open Access Journals (Sweden)

    Stine Vuholm

    2014-12-01

    Full Text Available Background: Differences in habitual dietary fiber intake may modify effects of dietary fiber interventions, thus measurement of habitual dietary fiber intake is relevant to apply in intervention studies on fiber-rich foods, and food frequency questionnaire (FFQ is a commonly used method. Rye bread is the major contributor of dietary fiber in the Danish population, and a nation-specific FFQ is therefore needed. Objective: The aim of this study was to assess the relative validity and reproducibility of a self-administered quantitative FFQ designed to assess total dietary fiber intake among Danish adults. Design: In order to assess the relative validity of the FFQ, a total of 125 participants completed both a 7-day weighed dietary recording (DR and an FFQ consisting of 60 questions. To evaluate the reproducibility of the FFQ, a sub-group of 12 participants subsequently completed an FFQ approximately 6 months later. Results: Estimates of mean dietary fiber intake were 24.9±9.8 and 28.1±9.4 g/day when applying the FFQ and DR, respectively, where FFQ estimates were ~12% lower (p<0.001. Pearson's correlation coefficient between the estimated dietary fiber intake of the two methods was r=0.63 (p<0.001, and 62% of the participants were grouped into the same tertile of intake according to the two methods. The estimates of mean dietary intake of first and second FFQ were very similar (22.2±4.0 and 23.3±4.1 g/day, respectively, p=0.42 and showed a correlation of r=0.95 (95% CI 0.83–0.99. Conclusion: The developed FFQ showed moderate underestimation of dietary fiber intake (g/day, adequate ranking of subjects according to their dietary fiber intake, and good reproducibility. The FFQ is therefore believed to be a valuable tool for epidemiology and screening in human interventions, where intake of dietary fibers is of specific interest.

  9. Increased Frequency of Suppressive Regulatory T Cells and T-cell Mediated Antigen Loss Results in Murine Melanoma Recurrence

    Science.gov (United States)

    Jensen, Shawn M.; Twitty, Christopher G.; Maston, Levi D.; Antony, Paul A.; Lim, May; Hu, Hong-Ming; Petrausch, Ulf; Restifo, Nicholas P.; Fox, Bernard A.

    2012-01-01

    Therapeutic treatment of large established tumors using immunotherapy has yielded few promising results. We investigated if adoptive transfer of tumor-specific CD8+ T cells together with tumor-specific CD4+ T cells would mediate regression of large established B16BL6-D5 (D5) melanomas in lymphopenic Rag1−/− recipients devoid of regulatory T cells. The combined adoptive transfer of subtherapeutic doses of both TRP1-specific TCR transgenic Rag1−/− CD4+ T cells and gp100-specific TCR transgenic Rag1−/− CD8+ T cells into lymphopenic recipients, that received vaccination, led to regression of large (100–400 mm2) melanomas. The same treatment strategy was ineffective in lymphoreplete wt mice. Twenty-five percent of mice (15/59) had tumors recur (15–180 days post regression). Recurrent tumors were depigmented and had decreased expression of gp100, the epitope targeted by the CD8+ T cells. Mice with recurrent melanoma had increased CD4+Foxp3+ TRP1-specific T cells compared to mice that did not show evidence of disease. Importantly, splenocytes from mice with recurrent tumor were able to suppress the in vivo therapeutic efficacy of splenocytes from tumor-free mice. These data demonstrate that large established tumors can be treated by a combination of tumor-specific CD8+ and CD4+ T cells. Additionally, recurrent tumors exhibited decreased antigen expression and were accompanied by conversion of the therapeutic tumor-specific CD4+ T cell population to a FoxP3+ CD4+ regulatory T cell population. PMID:22723522

  10. Altruistic cell suicide in relation to radiation hormesis

    International Nuclear Information System (INIS)

    The high radiosensitivity to killing of undifferentiated primordial cells (Bergonie and Tribondeau 1906) can be described as a manifestation of the suicide of injured cells for the benefit of an organism as a whole if their suicide stimulates proliferation of healthy cells to replace them, resulting in complete elimination of injury. This process is called cell-replacement repair, to distinguish it from DNA repair which is rarely complete. 'Cell suicide', 'programmed death' and 'apoptosis' are terms used for the same type of active cell death. Cell suicide is not always altruistic. Altruistic suicide in Drosophila, mice, humans, plants, and E. coli is reviewed in this paper to illustrate its widely different facets. The hypothesis that in animals, radiation hormesis results from altruistic cell suicide is proposed. This hypothesis can explain the hormetic effect of low doses of radiation on the immune system in mice. In contrast, in plants, radiation hormesis seems to be mainly due to non-altruistic cell death. (author)

  11. Cytogenetic "rogue" cells: what is their frequency, origin, and evolutionary significance?

    OpenAIRE

    Awa, A A; Neel, J V

    1986-01-01

    Among 102,170 cultured lymphocytes obtained from 9818 individuals from Hiroshima, Japan, aged 9 to 37 years and scored for chromosomal abnormalities, 24 cells that exhibited an extreme degree of damage were encountered. The damage consists of multiple dicentric and even tricentric chromosomes, as well as numerous fragments, many with the appearance of "double minutes." The occurrence of these cells was not correlated with parental exposure to the atomic bomb, age, sex, year, or season. They w...

  12. Learning Based Frequency- and Time-Domain Inter-Cell Interference Coordination in HetNets

    OpenAIRE

    Simsek, Meryem; Bennis, Mehdi; Guvenc, Ismail

    2014-01-01

    In this article, we focus on inter-cell interference coordination (ICIC) techniques in heterogeneous network (Het-Net) deployments, whereby macro- and picocells autonomously optimize their downlink transmissions, with loose coordination. We model this strategic coexistence as a multi-agent system, aiming at joint interference management and cell association. Using tools from Reinforcement Learning (RL), agents (i.e., macro- and picocells) sense their environment, and self-adapt based on local...

  13. Across-frequency behavioral estimates of the contribution of inner and outer hair cell dysfunction to individualized audiometric loss

    Directory of Open Access Journals (Sweden)

    Peter T. Johannesen

    2014-07-01

    Full Text Available Identifying the multiple contributors to the audiometric loss of a hearing impaired listener at a particular frequency is becoming gradually more useful as new treatments are developed. Here, we infer the contribution of inner (IHC and outer hair cell (OHC dysfunction to the total audiometric loss in a sample of 68 hearing aid candidates with mild-to-severe sensorineural hearing loss, and for test frequencies of 0.5, 1, 2, 4, and 6 kHz. It was assumed that the audiometric loss (HL_TOTAL at each test frequency was due to a combination of cochlear gain loss, or OHC dysfunction (HL_OHC, and inefficient IHC processes (HL_IHC, all of them in decibels. HL_OHC and HL_IHC were estimated from cochlear I/O curves inferred psychoacoustically using the temporal masking curve method. 325 I/O curves were measured and 59% of them showed a compression threshold. The analysis of these I/O curves suggests that (1 HL_OHC and HL_IHC account on average for 60-70% and 40-30% of HL_TOTAL, respectively; (2 these percentages are roughly constant across frequencies; (3 across-listener variability is large; (4 residual cochlear gain is negatively correlated with hearing loss while residual compression is not correlated with hearing loss. Altogether, the present results support the conclusions from earlier studies and extend them to a wider range of test frequencies and hearing loss ranges. 24% of I/O curves were linear and suggested total cochlear gain loss. The number of linear I/O curves increased gradually with increasing frequency. The remaining 17% I/O curves suggested audiometric losses due mostly to IHC dysfunction and were more frequent at low (≤ 1 kHz than at high frequencies. It is argued that in a majority of listeners, hearing loss is due to a common mechanism that concomitantly alters IHC and OHC function and that IHC processes may be more labile in the apex than in the base.

  14. Monitoring of regulatory T cell frequencies and expression of CTLA-4 on T cells, before and after DC vaccination, can predict survival in GBM patients.

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    Brendan Fong

    Full Text Available PURPOSE: Dendritic cell (DC vaccines have recently emerged as an innovative therapeutic option for glioblastoma patients. To identify novel surrogates of anti-tumor immune responsiveness, we studied the dynamic expression of activation and inhibitory markers on peripheral blood lymphocyte (PBL subsets in glioblastoma patients treated with DC vaccination at UCLA. EXPERIMENTAL DESIGN: Pre-treatment and post-treatment PBL from 24 patients enrolled in two Phase I clinical trials of dendritic cell immunotherapy were stained and analyzed using flow cytometry. A univariate Cox proportional hazards model was utilized to investigate the association between continuous immune monitoring variables and survival. Finally, the immune monitoring variables were dichotomized and a recursive partitioning survival tree was built to obtain cut-off values predictive of survival. RESULTS: The change in regulatory T cell (CD3(+CD4(+CD25(+CD127(low frequency in PBL was significantly associated with survival (p = 0.0228; hazard ratio = 3.623 after DC vaccination. Furthermore, the dynamic expression of the negative co-stimulatory molecule, CTLA-4, was also significantly associated with survival on CD3(+CD4(+ T cells (p = 0.0191; hazard ratio = 2.840 and CD3(+CD8(+ T cells (p = 0.0273; hazard ratio = 2.690, while that of activation markers (CD25, CD69 was not. Finally, a recursive partitioning tree algorithm was utilized to dichotomize the post/pre fold change immune monitoring variables. The resultant cut-off values from these immune monitoring variables could effectively segregate these patients into groups with significantly different overall survival curves. CONCLUSIONS: Our results suggest that monitoring the change in regulatory T cell frequencies and dynamic expression of the negative co-stimulatory molecules on peripheral blood T cells, before and after DC vaccination, may predict survival. The cut-off point generated from these data can be utilized in future

  15. High-power acoustic insult to living cultured cells as studied by high-frequency scanning acoustic microscopy

    Science.gov (United States)

    Miyasaka, Chiaki; Tittmann, Bernhard R.

    2002-06-01

    A plurality of articles discussing combined effects of acoustic high-pressure (mechanical factor) and heat (thermal factor) caused by acoustic vibration on biological tissues and cells has been published. Herein, we contribute the preliminary results describing the behavior of living human skin cells when separately applying shock waves and thermal insult to them. First, we gradually increased temperature of a culturing medium from 37.5 to 52 degree(s)C using the heat plate with temperature controller, and carried out in-situ observation of the cells grown on a substrate via the medium using a scanning acoustic microscope. Second, we provided the pressure using high power ultrasonic pulses generated by a laser induced ultrasonic shock wave system to the cells, wherein the pressure caused by the pulses was measured by a hydrophone, and wherein temperature was monitored by thermocouples. The cells were observed just after giving the impact. The difference between phenomena indicating cellular insult and injury (e.g., shrinkage or lift-off) were clearly visualized by the scanning acoustic microscope with frequency at 1.0 GHz.

  16. The Ultrasound effects on non tumoral cell line at 1 MHz therapeutic frequency

    International Nuclear Information System (INIS)

    The aim of this research is to investigate some bioeffects due to Therapeutic Ultrasound (1 MHz and 50PA2) which could allow to enhance drugs or genes delivery in non tumoral cells. Ultrasound (US) has been demonstrated to alter the cell membrane permeability due to a biophysical mechanism, Sonoporation, and exploited as a promising non-invasive gene transfer method. We have used the NIH-3T3 cell line as a model system and exposed it to US medical equipment for 15, 30, 45, 60 minutes at distances of 10 and 15 cm from the source transducer, corresponding to the far field region where z>α2/4/λ=4.0±0.4 cm. We have worked with the maximum power in pulsed system with 75% duty cycle. Characterization of the unfocused, planar and with a circular geometry 1 MHz source transducer, was performed and the acoustics pressure was measured by a calibrated 0.5 mm needle hydrophone; moreover, the pressure field generated by the source transducer was simulated. The US effects on cells were assessed by Fourier transform infrared (FTIR) Imaging with focal plane array (FPA) detector. By the IR analysis, the US exposure on non tumoral cells has induced a change of the intensity for CH2 asymmetric stretching (2924 cm-1) band in the lipid region (3000-2800 cm-1) that it could detect an energy-dependent process. It has already shown that cells invest energy to catalyze lipid movement in order to maintain a specific transmembrane phospholipid distribution. Although asymmetry is the rule for control cells, the loss of asymmetry could be associated with the permeability change of plasma membrane inducing temporary pores.

  17. The Ultrasound effects on non tumoral cell line at 1 MHz therapeutic frequency

    Science.gov (United States)

    Di Giambattista, L.; Grimaldi, P.; Udroiu, I.; Pozzi, D.; Cinque, G.; Frogley, M. D.; Cassarà, A. M.; Bedini, A.; Giliberti, C.; Palomba, R.; Buogo, S.; Giansanti, A.; Congiu Castellano, A.

    2011-02-01

    The aim of this research is to investigate some bioeffects due to Therapeutic Ultrasound (1 MHz and 50drugs or genes delivery in non tumoral cells. Ultrasound (US) has been demonstrated to alter the cell membrane permeability due to a biophysical mechanism, Sonoporation, and exploited as a promising non-invasive gene transfer method. We have used the NIH-3T3 cell line as a model system and exposed it to US medical equipment for 15, 30, 45, 60 minutes at distances of 10 and 15 cm from the source transducer, corresponding to the far field region where cm. We have worked with the maximum power in pulsed system with 75% duty cycle. Characterization of the unfocused, planar and with a circular geometry 1 MHz source transducer, was performed and the acoustics pressure was measured by a calibrated 0.5 mm needle hydrophone; moreover, the pressure field generated by the source transducer was simulated. The US effects on cells were assessed by Fourier transform infrared (FTIR) Imaging with focal plane array (FPA) detector. By the IR analysis, the US exposure on non tumoral cells has induced a change of the intensity for CH2 asymmetric stretching (2924 cm-1) band in the lipid region (3000-2800 cm-1) that it could detect an energy-dependent process. It has already shown that cells invest energy to catalyze lipid movement in order to maintain a specific transmembrane phospholipid distribution. Although asymmetry is the rule for control cells, the loss of asymmetry could be associated with the permeability change of plasma membrane inducing temporary pores.

  18. The Ultrasound effects on non tumoral cell line at 1 MHz therapeutic frequency

    Energy Technology Data Exchange (ETDEWEB)

    Di Giambattista, L; Grimaldi, P; Cassara, A M; Giansanti, A; Congiu Castellano, A [Physics Department, Sapienza, University of Rome (Italy); Udroiu, I; Bedini, A; Giliberti, C; Palomba, R [DIPIA, ISPESL, via Urbana 167, Rome (Italy); Pozzi, D [Experimental Medicine and Pathology Department, Sapienza, University of Rome (Italy); Cinque, G; Frogley, M D [Diamond Light Source Ltd, Didcot, Oxfordshire (United Kingdom); Buogo, S, E-mail: l.digiambattista@caspur.it [CNR-Institute of Acoustics O.M. Corbino, Rome (Italy)

    2011-02-01

    The aim of this research is to investigate some bioeffects due to Therapeutic Ultrasound (1 MHz and 50cells. Ultrasound (US) has been demonstrated to alter the cell membrane permeability due to a biophysical mechanism, Sonoporation, and exploited as a promising non-invasive gene transfer method. We have used the NIH-3T3 cell line as a model system and exposed it to US medical equipment for 15, 30, 45, 60 minutes at distances of 10 and 15 cm from the source transducer, corresponding to the far field region where z>{alpha}{sup 2}/4/{lambda}=4.0{+-}0.4 cm. We have worked with the maximum power in pulsed system with 75% duty cycle. Characterization of the unfocused, planar and with a circular geometry 1 MHz source transducer, was performed and the acoustics pressure was measured by a calibrated 0.5 mm needle hydrophone; moreover, the pressure field generated by the source transducer was simulated. The US effects on cells were assessed by Fourier transform infrared (FTIR) Imaging with focal plane array (FPA) detector. By the IR analysis, the US exposure on non tumoral cells has induced a change of the intensity for CH{sub 2} asymmetric stretching (2924 cm{sup -1}) band in the lipid region (3000-2800 cm{sup -1}) that it could detect an energy-dependent process. It has already shown that cells invest energy to catalyze lipid movement in order to maintain a specific transmembrane phospholipid distribution. Although asymmetry is the rule for control cells, the loss of asymmetry could be associated with the permeability change of plasma membrane inducing temporary pores.

  19. Effects of Plant Cell Wall Matrix Polysaccharides on Bacterial Cellulose Structure Studied with Vibrational Sum Frequency Generation Spectroscopy and X-ray Diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Bum; Lee, Christopher M; Kafle, Kabindra; Park, Sunkyu; Cosgrove, Daniel; Kim, Seong H

    2014-07-14

    The crystallinity, allomorph content, and mesoscale ordering of cellulose produced by Gluconacetobacter xylinus cultured with different plant cell wall matrix polysaccharides were studied with vibrational sum frequency generation (SFG) spectroscopy and X-ray diffraction (XRD).

  20. Frequency of γδ T Cells and Invariant Natural Killer T Cells in Helicobacter Pylori-infected Patients with Peptic Ulcer and Gastric Cancer.

    Science.gov (United States)

    Shadman, Mojtaba; Rajabian, Zeinab; Ajami, Abolghasem; Hussein-Nattaj, Hadi; Rafiei, Alireza; Hosseini, Vahid; Taghvaei, Tarang; Abbasi, Ali; Tehrani, Mohsen

    2015-10-01

    To clarify the effect of γδ T cells and invariant Natural Killer T (iNKT) cells in pathophysiology of dyspeptic disorders, number of these two cells in patients with non-ulcer dyspepsia (NUD), peptic ulcer disease (PUD), and gastric cancer (GC) were compared.Patients with dyspepsia were divided into three groups of NUD, PUD, and GC according to their endoscopic and histopathological examinations. Helicobacter pylori infection was diagnosed by rapid urease test and histopathology. The number of peripheral blood CD3+TCRγδ(+) T cells and CD3+Va24Ja18+ iNKT cells were determined by flow cytometry. Immunohistochemistry (IHC) was also used for identifying the TCRγδ+ cells.Forty two patients with NUD (31.6%), 44 with PUD (33.1%), and 47 with GC (35.3%) were included in the study. The frequency of CD3+TCRγδ(+) T cells in peripheral blood of patients with GC (2.71±0.25) was significantly lower than that in NUD (3.97±0.32, pgastric cancer.

  1. Human immunodeficiencies related to APC/T cell interaction

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    Marinos eKallikourdis

    2015-08-01

    Full Text Available The primary event for initiating adaptive immune responses is the encounter between T lymphocytes and antigen presenting cells (APC in the T cell area of secondary lymphoid organs and the formation of highly organized inter-cellular junctions referred to as the immune synapses. In vivo live-cell imaging of APC-T cell interactions combined to functional studies unveiled that T cell fate is dictated, in large part, by the stability of the initial contact. Immune cell interaction is equally important during delivery of T cell help to B cells and for the killing of target cells by cytotoxic T cells and NK cells. The critical role of contact dynamics and synapse stability on the immune response is well illustrated by human immune deficiencies in which disease pathogenesis is linked to altered adhesion or defective cross-talk between the synaptic partners. Here we will discuss in details the mechanisms of defective APC-T cell communications in Wiskott-Aldrich syndrome (WAS and in warts, hypogammaglobulinemia, infections, myelokathexis syndrome (WHIM. In addition, we will summarize the evidences pointing to a compromised conjugate formation in WIP deficiency, DOCK8 deficiency and X-linked lymphoproliferative syndrome.

  2. Celiac disease T-cell epitopes from gamma-gliadins: immunoreactivity depends on the genome of origin, transcript frequency, and flanking protein variation

    Directory of Open Access Journals (Sweden)

    Salentijn Elma MJ

    2012-06-01

    Full Text Available Abstract Background Celiac disease (CD is caused by an uncontrolled immune response to gluten, a heterogeneous mixture of wheat storage proteins. The CD-toxicity of these proteins and their derived peptides is depending on the presence of specific T-cell epitopes (9-mer peptides; CD epitopes that mediate the stimulation of HLA-DQ2/8 restricted T-cells. Next to the thoroughly characterized major T-cell epitopes derived from the α-gliadin fraction of gluten, γ-gliadin peptides are also known to stimulate T-cells of celiac disease patients. To pinpoint CD-toxic γ-gliadins in hexaploid bread wheat, we examined the variation of T-cell epitopes involved in CD in γ-gliadin transcripts of developing bread wheat grains. Results A detailed analysis of the genetic variation present in γ-gliadin transcripts of bread wheat (T. aestivum, allo-hexaploid, carrying the A, B and D genome, together with genomic γ-gliadin sequences from ancestrally related diploid wheat species, enabled the assignment of sequence variants to one of the three genomic γ-gliadin loci, Gli-A1, Gli-B1 or Gli-D1. Almost half of the γ-gliadin transcripts of bread wheat (49% was assigned to locus Gli-D1. Transcripts from each locus differed in CD epitope content and composition. The Gli-D1 transcripts contained the highest frequency of canonical CD epitope cores (on average 10.1 per transcript followed by the Gli-A1 transcripts (8.6 and the Gli-B1 transcripts (5.4. The natural variants of the major CD epitope from γ-gliadins, DQ2-γ-I, showed variation in their capacity to induce in vitro proliferation of a DQ2-γ-I specific and HLA-DQ2 restricted T-cell clone. Conclusions Evaluating the CD epitopes derived from γ-gliadins in their natural context of flanking protein variation, genome specificity and transcript frequency is a significant step towards accurate quantification of the CD toxicity of bread wheat. This approach can be used to predict relative levels of CD toxicity of

  3. Ascertainment of the effect of differential growth rates of mutants on observed mutant frequencies in X-irradiated mammalian cells

    International Nuclear Information System (INIS)

    As it is not known to what extent differential growth rates of induced mutants lead to over- and under-representation of mutants in treated populations and thereby affect the determination of mutant frequencies, the mutation induction in X-irradiated L5178Y mouse lymphoma cells was determined via two methods. The first method involves the standard protocol which may suffer from the effect of differential growth rates, while the second method is based upon the fluctuation test in which the differential growth rates can be actually measured. It appeared that the standard protocol led to a mutant frequency that was similar to the mutant frequency determined in the fluctuation test. Therefore, the standard protocol appears to lead to only a minor under-estimation if any. Substantial heterogeneity in growth rates of induced mutants was observed, but the mutants with a selective advantage appear largely to compensate for the mutants that are lost because of selective disadvantage. It was calculated that the chance for isolating the same mutant twice from a treated population had been increased 2.2-fold because of the observed differential growth rates. (orig./AJ)

  4. A human monoclonal antibody to high-frequency red cell antigen Jra.

    Science.gov (United States)

    Miyazaki, T; Kwon, K W; Yamamoto, K; Tone, Y; Ihara, H; Kato, T; Ikeda, H; Sekiguchi, S

    1994-01-01

    A human-mouse heterohybridoma (HMR0921) secreting human monoclonal IgG3, lambda antibody was produced from peripheral blood lymphocytes of a healthy blood donor with serum antibody to Jra, by EBV transformation and hybridization with mouse myeloma cell line P3X63Ag8.653. The reactivity of HMR0921 antibody was assessed by antiglobulin test with a panel of red cells including 14 different rare blood types. Only Jr(a-) red cells were negative. The strict specificity of this antibody to Jra antigen was further confirmed by absorption test with fluorescence flow cytometry. On screening of 28,744 blood donor samples by HMR0921 antibody, we detected 19 agglutination-negative samples, which were confirmed as Jr(a-) by conventional anti-Jra antisera. Therefore, our HMR0921 antibody is extremely useful for detecting rare Jr(a-) blood.

  5. Frequencies of red blood cell major blood group antigens and phenotypes in the Chinese Han population from Mainland China.

    Science.gov (United States)

    Yu, Y; Ma, C; Sun, X; Guan, X; Zhang, X; Saldanha, J; Chen, L; Wang, D

    2016-08-01

    Alloantibodies directed to red blood cell (RBC) antigens play an important role in alloimmune-mediated haemolytic transfusion reactions and haemolytic disease of the foetus and newborn. The frequencies and phenotypes of RBC antigens are different in populations from different geographic areas and races. However, the data on major blood group antigens in the Chinese Han population from Mainland China are still very limited; thus, we aimed to investigate them in this study. A total of 1412 unrelated voluntary Chinese Han blood donors were randomly recruited. All donors were typed for blood group antigens: D, C, c, E, e, C(w) , Jk(a) , Jk(b) ,M, N, S, s, Le(a) , Le(b) , K, k. Kp(a) , Kp(b) , Fy(a) , Fy(b) , Lu(a) , Lu(b) , P1 and Di(a) using serological technology. Calculations of antigen and phenotype frequencies were expressed as percentages and for allele frequencies under the standard assumption of Hardy-Weinberg equilibrium. Amongst the Rh antigens, D was the most common (98.94%) followed by e (92.28%), C (88.81%), c (58.43%), E (50.78%) and C(w) (0.07%) with DCe/DCe (R1 R1 , 40.72%) being the most common phenotype. In the Kell blood group system, k was present in 100% of the donors and a rare phenotype, Kp (a+b+), was found in 0.28% of the donors. For the Kidd and Duffy blood group systems, Jk (a+b+) and Fy (a+b-) were the most common phenotypes (44.05% and 84.35%, respectively). In the MNS blood group system, M+N+S-s+ (45.54%) was the most common, whereas M+N-S-s- and M-N+S-s- were not found. The rare Lu (a-b-) and Lu (a+b+) phenotypes were identified in 0.43% and 1.13% of the donors, respectively. Le(a) and Le(b) were seen in 17.92% and 63.03% of donors, respectively. The frequency of Di(a) was 4.75%, which was higher than in the Chinese population in Taiwan region or the Caucasian and Black populations (P < 0.0001). This study systematically describes the frequencies of 24 blood group antigens in the Chinese Han population from Mainland China. The data can

  6. On a relation of the angular frequency to the Aharonov-Casher geometric phase in a quantum dot

    Science.gov (United States)

    Barboza, P. M. T.; Bakke, K.

    2016-09-01

    By analysing the behaviour of a neutral particle with permanent magnetic dipole moment confined to a quantum dot in the presence of a radial electric field, Coulomb-type and linear confining potentials, then, an Aharonov-Bohm-type effect for bound states and a dependence of the angular frequency of the system on the Aharonov-Casher geometric phase and the quantum numbers associated with the radial modes, the angular momentum and the spin are obtained. In particular, the possible values of the angular frequency and the persistent spin currents associated with the ground state are investigated in two different cases. article>

  7. Low-frequency noise, microplasma, and electroluminescence measurements as faster tools to investigate quality of monocrystalline-silicon solar cells

    Science.gov (United States)

    Chobola, Zdenek; Lunak, Miroslav; Vanek, Jiri; Barinka, Radim

    2013-05-01

    Two sets of c-Si solar cells varying in front side phosphorus doped emitters were produced by standard screen printing techniques. The first group of samples, 3121, was prepared by a combination of standard washing and a bath with a highly dilute HF before diffusion of n+-emitter. The second group of samples, 3122, was treated only with standard washing. A comparison of solar cell conversion efficiency and results from a noise spectroscopy, microplasma, and electroluminescence presence are presented. As was already shown in previous publications noise spectral density reflects the quality of solar cells, and thus represents an alternative advanced cell diagnostic tool. Our results confirm this relationship and moreover bring clear evidence for the maximum spectral noise voltage density being related to the emitter structure. The best results were reached for the group of solar cells in sample 3122, which was treated only with standard washing.

  8. Evidence that in xeroderma pigmentosum variant cells, which lack DNA polymerase eta, DNA polymerase iota causes the very high frequency and unique spectrum of UV-induced mutations.

    Science.gov (United States)

    Wang, Yun; Woodgate, Roger; McManus, Terrence P; Mead, Samantha; McCormick, J Justin; Maher, Veronica M

    2007-04-01

    Xeroderma pigmentosum variant (XPV) patients have normal DNA excision repair, yet are predisposed to develop sunlight-induced cancer. They exhibit a 25-fold higher than normal frequency of UV-induced mutations and very unusual kinds (spectrum), mainly transversions. The primary defect in XPV cells is the lack of functional DNA polymerase (Pol) eta, the translesion synthesis DNA polymerase that readily inserts adenine nucleotides opposite photoproducts involving thymine. The high frequency and striking difference in kinds of UV-induced mutations in XPV cells strongly suggest that, in the absence of Pol eta, an abnormally error-prone polymerase substitutes. In vitro replication studies of Pol iota show that it replicates past 5'T-T3' and 5'T-U3' cyclobutane pyrimidine dimers, incorporating G or T nucleotides opposite the 3' nucleotide. To test the hypothesis that Pol iota causes the high frequency and abnormal spectrum of UV-induced mutations in XPV cells, we identified an unlimited lifespan XPV cell line expressing two forms of Pol iota, whose frequency of UV-induced mutations is twice that of XPV cells expressing one form. We eliminated expression of one form and compared the parental cells and derivatives for the frequency and kinds of UV-induced mutations. All exhibited similar sensitivity to the cytotoxicity of UV((254 nm)), and the kinds of mutations induced were identical, but the frequency of mutations induced in the derivatives was reduced to UV-induced mutations, and ultimately their malignant transformation.

  9. Non-integrative lentivirus drives high-frequency cre-mediated cassette exchange in human cells.

    Directory of Open Access Journals (Sweden)

    Raul Torres

    Full Text Available Recombinase mediated cassette exchange (RMCE is a two-step process leading to genetic modification in a specific genomic target sequence. The process involves insertion of a docking genetic cassette in the genome followed by DNA transfer of a second cassette flanked by compatible recombination signals and expression of the recombinase. Major technical drawbacks are cell viability upon transfection, toxicity of the enzyme, and the ability to target efficiently cell types of different origins. To overcome such drawbacks, we developed an RMCE assay that uses an integrase-deficient lentivirus (IDLV vector in the second step combined with promoterless trapping of double selectable markers. Additionally, recombinase expression is self-limiting as a result of the exchangeable reaction, thus avoiding toxicity. Our approach provides proof-of-principle of a simple and novel strategy with expected wide applicability modelled on a human cell line with randomly integrated copies of a genetic landing pad. This strategy does not present foreseeable limitations for application to other cell systems modified by homologous recombination. Safety, efficiency, and simplicity are the major advantages of our system, which can be applied in low-to-medium throughput strategies for screening of cDNAs, non-coding RNAs during functional genomic studies, and drug screening.

  10. Very high frequency plasma deposited amorphous/nanocrystalline silicon tandem solar cells on flexible substrates

    NARCIS (Netherlands)

    Liu, Y.

    2010-01-01

    The work in this thesis is to develop high quality intrinsic layers (especially nc-Si:H) for micromorph silicon tandem solar cells/modules on plastic substrates following the substrate transfer method or knows as the Helianthos procedure. Two objectives are covered in this thesis: (1) preliminary wo

  11. Frequencies and role of regulatory T cells in patients with (pre)malignant cervical neoplasia

    NARCIS (Netherlands)

    Visser, J.; Nijman, H. W.; Hoogenboom, B.-N.; Jager, P.; van Baarle, D.; Schuuring, E.; Abdulahad, W.; Miedema, F.; van der Zee, A. G.; Daemen, T.

    2007-01-01

    Oncogenic human papillomavirus (HPV)-infection is crucial for developing cervical cancer and its precursor lesions [cervical intraepithelial neoplasia (CIN)]. Regulatory T cells (T-regs) might be involved in the failure of the immune system to control the development of HPV-induced cancer. We invest

  12. Investigating the effects of 217 Hz frequency of cell phone on learning and spatial memory in rats

    Directory of Open Access Journals (Sweden)

    Kohzad S

    2013-03-01

    Full Text Available Background: Extremely low frequency (0-300 Hz fields from power lines, electronic equipment and medical devices, have been reported to produce various biological effects. Global system for mobile (GSM is most largely used in everybody's life. This system utilizes a low frequency band as well as a high frequency range of electromagnetic field. This study investigated the effects of 217 Hz electromagnetic field (the modulating signal in GSM on spatial learning and memory in rat.Methods: Twenty four male Wistar rat (200- 250 g were randomly divided in to three groups as: test, sham and control. Using a Helmholtz coil system, the test group was exposed to a uniform pulsed EMF of 200 µT (micro Tesla intensity for 4 h/day for 21 days (2 time in a day. This procedure was repeated for the sham group but with no field. All groups were trained prior to the day 21 on the 15th day for five days four trial per day in Morris Water-Maze system. Then the probe test was carried out for 60 seconds with no platform.Results: The ANOVA test revealed that no significant differences were found between control and exposed rats in all day of learning acquisition. Also, in probe test for investigating the memory, no significant differences observed. (P≤0.05 is accepted for significant level.Conclusion: This finding is in consistent with previous studies and indicates low frequency band of electromagnetic fields (EMF (200 µT intensity in cell phone may not have any effect on the learning acquisition and spatial memory in rat.

  13. Chromatin remodeling and stem cell theory of relativity.

    Science.gov (United States)

    Cerny, Jan; Quesenberry, Peter J

    2004-10-01

    The field of stem cell biology is currently being redefined. Stem cell (hematopoietic and non-hematopoietic) differentiation has been considered hierarchical in nature, but recent data suggest that there is no progenitor/stem cell hierarchy, but rather a reversible continuum. The stem cell (hematopoietic and non-hematopoietic) phenotype, the total differentiation capacity (hematopoietic and non-hematopoietic), gene expression as well as other stem cell functional characteristics (homing, receptor and adhesion molecule expression) vary throughout a cell-cycle transit widely. This seems to be dependent on shifting chromatin and gene expression with cell-cycle transit. The published data on DNA methylation, histone acetylation, and also RNAi, the major regulators of gene expression, conjoins very well and provides an explanation for the major issues of stem cell biology. Those features of stem cells mentioned above can be rather difficult to apprehend when a classical hierarchy biology view is applied, but they become clear and easier to understand once they are correlated with the underlining epigenetic changes. We are entering a new era of stem cell biology the era of "chromatinomics." We are one step closer to the practical use of cellular therapy for degenerative diseases.

  14. Individualism and Socioeconomic Diversity at School as Related to Perceptions of the Frequency of Peer Aggression in Fifteen Countries

    Science.gov (United States)

    Menzer, Melissa M.; Torney-Purta, Judith

    2012-01-01

    The purpose of this study was to examine two aspects of context for peer aggression: national individualism and distributions of socioeconomic status in the school. School administrators for each school reported on their perceptions of the frequency of bullying and violence in their school. The sample comprised 990 school principals/headmasters…

  15. Relation between frequency of seismic wave and resolution of tomography; Danseiha tomography kaiseki ni okeru shuhasu to bunkaino no kankei

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, M.; Watanabe, T.; Ashida, Y.; Sassa, K. [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1997-05-27

    With regard to the elastic wave exploration, discussions have been given on the relationship between frequency and resolution in P-wave velocity tomography using the initial travel time. The discussions were carried out by using a new analysis method which incorporates the concept of Fresnel volume into tomography analysis. The following two arrangements were used in the calculation: a cross hole arrangement, in which seismic source and vibration receiving points were arranged so as to surround the three directions of a region extending 250 m in the horizontal direction and 500 m in the vertical direction, and observation is performed between two wells, and a permeation VSP arrangement in which the seismic source is installed on the ground surface and receiving points installed in wells. Restructuring was performed on the velocity structure by using a total of 819 observation travel times. This method has derived results of the restructuring according to frequencies of the seismic source used for the exploration. The resolution shown in the result of the restructuring has become higher as elastic waves with higher frequency are used, and the size of the structure identified from the restructuring result has decreased. This fact reveals that sufficient considerations must be given on frequencies of elastic waves used according to size of objects to be explored. 4 refs., 4 figs.

  16. Naturally Occurring Changes in Time Spent Watching Television Are Inversely Related to Frequency of Physical Activity during Early Adolescence

    Science.gov (United States)

    Motl, Robert W.; McAuley, Edward; Birnbaum, Amanda S.; Lytle, Leslie A.

    2006-01-01

    In this longitudinal study, we examined the relationship between changes in time spent watching television and playing video games with frequency of leisure-time physical activity across a 2-year period among adolescent boys and girls (N=4594). Latent growth modelling indicated that a decrease in time spent watching television was associated with…

  17. Size-related variation in arm damage frequency in the crown-of-thorns sea star, Acanthaster planci

    Institute of Scientific and Technical Information of China (English)

    Jairo Rivera-Posada; Ciemon F Caballes; Morgan S Pratchett

    2014-01-01

    Objective: To examine variation in the frequency of arm damage in different sizes of Acanthasterplanci (A. planci), assess how this damage is inflicted by fish predators, and infer the potential role of predation in population regulation. Methods:and arm damage frequency and severity was assessed. Frequency of arm damage was compared between sizes. Feeding behavior of fish predators was also observed in the laboratory. Results:This study demonstrates that sublethal predation by triggerfishes on A. planci result inDiameters of A. planci collected from three sites in the Philippines were measured extensive arm damage. Overall, 60% of A. planci sampled across all sites had sublethal injuries. The frequency of individuals with missing or regenerating arms was highest in medium-sized young adults (11-20 cm), which coincides with the phase where A. planci shift from cryptic to exposed daytime feeding. Conclusions: The high incidence of arm damage within intermediate-sized sea stars indicates that predators exercise some level of regulation on A. planci populations at a local scale. Identification and protection of putative predators that target the most vulnerable life history stages of A. planci are essential in developing population control strategies and reverse sustained declines in coral cover.

  18. COMPREHENSIVE ASSESSMENT OF THE RELATIVE FREQUENCY OF SLEEP DISORDERS IN MIGRAINE AND NON MIGRAINE IN 6- TO 14-YEAR-OLD CHILDREN

    OpenAIRE

    Omid Yaghini MD; Seyyed Mohammad Amirshahkarami MD; Touran Mahmoudian MD; Elham Haj Hashemi MD

    2011-01-01

    ObjectiveHeadaches are common during childhood. In addition, sleep disorders are common problems in children, too. Although it is commonly thought thatheadache and sleep problems are related, there is not enough evidence to confirm this relationship. Finding evident relations between these problemswould help practitioners a lot to make earlier diagnosis and plan treatment modalities for both problems as soon as possible. This study aimed to assess therelative frequency of sleep disorders in m...

  19. Liver Label Retaining Cancer Cells Are Relatively Resistant to the Reported Anti-Cancer Stem Cell Drug Metformin

    OpenAIRE

    Xin, Hong-Wu; Ambe, Chenwi M.; Miller, Tyler C.; Chen, Jin-Qiu; Wiegand, Gordon W.; Anderson, Andrew J.; Ray, Satyajit; Mullinax, John E.; Hari, Danielle M; Koizumi, Tomotake; Godbout, Jessica D.; Goldsmith, Paul K.; Stojadinovic, Alexander; Rudloff, Udo; Thorgeirsson, Snorri S.

    2016-01-01

    Background & Aims: Recently, we reported that liver Label Retaining Cancer Cells (LRCC) can initiate tumors with only 10 cells and are relatively resistant to the targeted drug Sorafenib, a standard of practice in advanced hepatocellular carcinoma (HCC). LRCC are the only cancer stem cells (CSC) isolated alive according to a stem cell fundamental function, asymmetric cell division. Metformin has been reported to preferentially target many other types of CSC of different organs, including live...

  20. Age-related changes in antral endocrine cells in mice

    OpenAIRE

    Sandstrom, O.; Mahdavi, J.; El-Salhy, M.

    1999-01-01

    Antral endocrine cells in four age groups of mice, namely prepubertal (1 month old), young (3 months old), ageing (12 months old) and senescent (24 months old), were detected by immunocytochemistry and quantified by computerized image analysis. A statistical difference was detected between the different age groups regarding the numbers of gastrin-, somatostatin-, and serotonin-immunoreactive cells. The number of gastrin-immunoreactive cells significantly increa...

  1. Cell adhesion molecules during odontogenesis and tooth-related diseases

    OpenAIRE

    Heymann, Robert

    2002-01-01

    Cell adhesion molecules play essential roles in the development and disease of tooth and oral structures, as well as in the maintenance of adult tissue structure/function. It has been shown that different types of cell adhesion molecules (CAMs) play an important part in craniofacial development when ectomesenchymal cells migrate from the neural list to the primitive oral cavity, giving rise to the palatal processes and tooth germs. The role of CAMs in craniofacial developmen...

  2. Lightning Jump Algorithm and Relation to Thunderstorm Cell Tracking, GLM Proxy and Other Meteorological Measurements

    Science.gov (United States)

    Schultz, Christopher J.; Carey, Lawrence D.; Cecil, Daniel J.; Bateman, Monte

    2012-01-01

    The lightning jump algorithm has a robust history in correlating upward trends in lightning to severe and hazardous weather occurrence. The algorithm uses the correlation between the physical principles that govern an updraft's ability to produce microphysical and kinematic conditions conducive for electrification and its role in the development of severe weather conditions. Recent work has demonstrated that the lightning jump algorithm concept holds significant promise in the operational realm, aiding in the identification of thunderstorms that have potential to produce severe or hazardous weather. However, a large amount of work still needs to be completed in spite of these positive results. The total lightning jump algorithm is not a stand-alone concept that can be used independent of other meteorological measurements, parameters, and techniques. For example, the algorithm is highly dependent upon thunderstorm tracking to build lightning histories on convective cells. Current tracking methods show that thunderstorm cell tracking is most reliable and cell histories are most accurate when radar information is incorporated with lightning data. In the absence of radar data, the cell tracking is a bit less reliable but the value added by the lightning information is much greater. For optimal application, the algorithm should be integrated with other measurements that assess storm scale properties (e.g., satellite, radar). Therefore, the recent focus of this research effort has been assessing the lightning jump's relation to thunderstorm tracking, meteorological parameters, and its potential uses in operational meteorology. Furthermore, the algorithm must be tailored for the optically-based GOES-R Geostationary Lightning Mapper (GLM), as what has been observed using Very High Frequency Lightning Mapping Array (VHF LMA) measurements will not exactly translate to what will be observed by GLM due to resolution and other instrument differences. Herein, we present some of

  3. Recent advances in andrology-related stem cell research

    Institute of Scientific and Technical Information of China (English)

    Ching-Shwun Lin; Zhong-Cheng Xin; Chun-Hua Deng; Hongxiu Ning; Ouiting Lin; Tom F. Lue

    2008-01-01

    Stem cells hold great promise for regenerative medicine because of their ability to self-renew and to differentiate into various cell types. Although embryonic stem cells (BSC) have greater differentiation potential than adult stem cells, the former is lagging in reaching clinical applications because of ethical concerns and governmental restrictions.Bone marrow stem cells (BMSC) are the best-studied adult stem cells (ASC) and have the potential to treat a wide variety of diseases, including erectile dysfunction (ED) and male infertility. More recently discovered adipose tissue-derived stem cells (ADSC) are virtually identical to bone marrow stem cells in differentiation and therapeutic potential,but are easier and safer to obtain, can be harvested in larger quantities, and have the associated benefit of reducing obesity. Therefore, ADSC appear to be a better choice for future clinical applications. We have previously shown that ESC could restore the erectile function of neurogenic ED in rats, and we now have evidence that ADSC could do so as well. We are also investigating whether ADSC can differentiate into Leydig, Sertoli and male germ cells. The eventual goal is to use ADSC to treat male infertility and testosterone deficiency.

  4. Relationship between seizure frequency and number of neuronal and non-neuronal cells in the hippocampus throughout the life of rats with epilepsy.

    Science.gov (United States)

    Lopim, Glauber Menezes; Vannucci Campos, Diego; Gomes da Silva, Sérgio; de Almeida, Alexandre Aparecido; Lent, Roberto; Cavalheiro, Esper Abrão; Arida, Ricardo Mario

    2016-03-01

    The relationship between seizure frequency and cell death has been a subject of controversy. To tackle this issue, we determined the frequency of seizures and the total number of hippocampal cells throughout the life of rats with epilepsy using the pilocarpine model. Seizure frequency varied in animals with epilepsy according to which period of life they were in, with a progressive increase in the number of seizures until 180 days (sixth months) of epileptic life followed by a decrease (330 days-eleventh month) and subsequently stabilization of seizures. Cell counts by means of isotropic fractionation showed a reduction in the number of hippocampal neuronal cells following 30, 90, 180 and 360 days of spontaneous recurrent seizures (SRS) in rats compared to their controls (about 25%-30% of neuronal cell reduction). In addition, animals with 360 days of SRS showed a reduction in the number of neuronal cells when compared with animals with 90 and 180 days of seizures. The total number of hippocampal non-neuronal cells was reduced in rats with epilepsy after 30 days of SRS, but no significant alteration was observed on the 90th, 180th and 360th days. The total number of neuronal cells was negatively correlated with seizure frequency, indicating an association between occurrence of epileptic seizures throughout life and neuronal loss. In sum, our results add novel data to the literature concerning the time-course of SRS and hippocampal cell number throughout epileptic life.

  5. Successful second transplantation from haploidentical donor for graft failure following unrelated cord blood cell transplantation or mismatched related transplantation: 2cases report

    Institute of Scientific and Technical Information of China (English)

    XU Lan-ping; HUANG Xiao-jun

    2006-01-01

    @@ Cord blood transplantation (CBT) from unrelated donors has increasingly been performed worldwide during the last decade. The immaturity of lymphocytes in cord blood permits HLA-mismatching between donors and recipients and reduces the severity of graft-versus-host disease (GVHD).However, the relatively small dose of the cord blood nucleated cells is associated with a high frequency of engraftment failure.1-5 But re-transplantation with stem cells from the original donor is impossible.

  6. The effects of sex, age and cigarette smoking on micronucleus and degenerative nuclear alteration frequencies in human buccal cells of healthy Bosnian subjects

    Directory of Open Access Journals (Sweden)

    Hilada Nefić

    2013-12-01

    Full Text Available Introduction: This study was performed to establish a baseline value of micronucleus frequency in buccal cells and to estimate the impact of the most common factors (sex and age, and smoking on micronucleus and degenerative nuclear alteration frequencies in the sample of healthy Bosnian subjects.Methods: The Buccal Micronucleus Cytome (BMCyt assay, based on scoring not only micronucleus frequency but also other genome damage markers, dead or degenerated cells, provides a measure of cytotoxic and genotoxic effects.Results: Our results showed the baseline buccal micronucleus frequency was 0.135% or 1.35‰, as well as positive correlations between micronucleus frequencies and formations of degenerative nuclear alterations (nuclear buds, karyolytic and karyorrhectic cells. The number of micronuclei in buccal cells was significantly higher in females than in males. There was positive association between the age and frequency of analysed cytogenetic biomarkers. Buccal cell micronuclei and degenerative nuclear alternations were more frequent among cigarette smokers than non-smokers and significantly higher in female smokers than in male smokers. Cytogenetic damages showed significantly positive correlation between intensity of smoking and the number of nuclear alterations. The years of smoking had a significant influence not only on the number of nuclear alterations but also in micronuclei and nuclear buds in buccal cells.Conclusions: The sex influences the number of micronuclei in human buccal cells. The ageing increased the number of micronuclei and other biomarkers of DNA damage. The cigarette smoking significantly increases the frequencies of micronuclei and nuclear buds, pyknotic, karyolytic and karyorrhectic cells.

  7. Calcitonin gene-related peptide regulates type IV hypersensitivity through dendritic cell functions.

    Directory of Open Access Journals (Sweden)

    Norihisa Mikami

    Full Text Available Dendritic cells (DCs play essential roles in both innate and adaptive immune responses. In addition, mutual regulation of the nervous system and immune system is well studied. One of neuropeptides, calcitonin gene-related peptide (CGRP, is a potent regulator in immune responses; in particular, it has anti-inflammatory effects in innate immunity. For instance, a deficiency of the CGRP receptor component RAMP 1 (receptor activity-modifying protein 1 results in higher cytokine production in response to LPS (lipopolysaccharide. On the other hand, how CGRP affects DCs in adaptive immunity is largely unknown. In this study, we show that CGRP suppressed Th1 cell differentiation via inhibition of IL-12 production in DCs using an in vitro co-culture system and an in vivo ovalbumin-induced delayed-type hypersensitivity (DTH model. CGRP also down-regulated the expressions of chemokine receptor CCR2 and its ligands CCL2 and CCL12 in DCs. Intriguingly, the frequency of migrating CCR2(+ DCs in draining lymph nodes of RAMP1-deficient mice was higher after DTH immunization. Moreover, these CCR2(+ DCs highly expressed IL-12 and CD80, resulting in more effective induction of Th1 differentiation compared with CCR2(- DCs. These results indicate that CGRP regulates Th1 type reactions by regulating expression of cytokines, chemokines, and chemokine receptors in DCs.

  8. Radiation-induced chromosome aberrations in ataxia telangiectasia cells: high frequency of deletions and misrejoining detected by fluorescence in situ hybridization

    Science.gov (United States)

    Kawata, Tetsuya; Ito, Hisao; George, Kerry; Wu, Honglu; Uno, Takashi; Isobe, Kouichi; Cucinotta, Francis A.

    2003-01-01

    The mechanisms underlying the hyper-radiosensitivity of AT cells were investigated by analyzing chromosome aberrations in the G(2) and M phases of the cell cycle using a combination of chemically induced premature chromosome condensation (PCC) and fluorescence in situ hybridization (FISH) with chromosome painting probes. Confluent cultures of normal fibroblast cells (AG1522) and fibroblast cells derived from an individual with AT (GM02052) were exposed to gamma rays and allowed to repair at 37 degrees C for 24 h. At doses that resulted in 10% survival, GM02052 cells were approximately five times more sensitive to gamma rays than AG1522 cells. For a given dose, GM02052 cells contained a much higher frequency of deletions and misrejoining than AG1522 cells. For both cell types, a good correlation was found between the percentage of aberrant cells and cell survival. The average number of color junctions, which represent the frequency of chromosome misrejoining, was also found to correlate well with survival. However, in a similar surviving population of GM02052 and AG1522 cells, induced by 1 Gy and 6 Gy, respectively, AG1522 cells contained four times more color junctions and half as many deletions as GM02052 cells. These results indicate that both repair deficiency and misrepair may be involved in the hyper-radiosensitivity of AT cells.

  9. Characterization of B cell responses in relation to organ transplantation

    NARCIS (Netherlands)

    Heidt, Sebastiaan

    2010-01-01

    Antibody-mediated rejection is increasingly recognised within the transplantation community as a cause or contributing factor in the rejection of transplanted organs. The humoral immune response towards allografts involves B cells that, after T cell dependent activation, can differentiate into antib

  10. Glia, mast cells and related: new therapeutic perspectives?

    Directory of Open Access Journals (Sweden)

    Guido Orlandini

    2011-09-01

    Full Text Available Glia exerts a pathogenic role in the development and maintenance of pain. In the past, glia was considered only support material; the glia is 70 to 90 percent of the CNS cells. Normally in a resting state, it is activated by substances released from central terminals of C fibers and releases cytokines that enhance excitatory synaptic transmission in the dorsal horn of the spinal cord (that is the basis of central sensitization, with allodynia-hyperalgesia. By analogy with the role of glia, it has been suggested the importance of the mast cell, a connective ubiquitous cell filled with granules that contain histamine, heparin, serotonin, and NGF as well as lipid droplets that contain hyaluronic acid and a cell membrane on which cannabinoid receptors 1 and 2 and vanilloid are located. Nociceptive stimuli cause mast cell degranulation and the release of substances contained in the granules. ___________________________________________________

  11. Development of a Relation between Slot Lengths of Microstrip Antenna and Its Resonant Frequencies Using Soft Computing Tool

    Directory of Open Access Journals (Sweden)

    P.Pradhan

    2012-04-01

    Full Text Available A new method of calculation of resonant frequencyof a rectangular patch antenna using Artificial NeuralNetwork (ANN has been adopted in this paper.ANN model has been developed and tested infrequency range of 1GHz to 3GHz to analyzeresonant frequency and slot length in rectangularMicrostrip Patch Antenna. The results obtained usingANN, are compared to the results obtained usingsoftware FEKO and experiment.

  12. Platelets surrounding primary tumor cells are related to chemoresistance.

    Science.gov (United States)

    Ishikawa, Satoko; Miyashita, Tomoharu; Inokuchi, Masafumi; Hayashi, Hironori; Oyama, Katsunobu; Tajima, Hidehiro; Takamura, Hironori; Ninomiya, Itasu; Ahmed, A Karim; Harman, John W; Fushida, Sachio; Ohta, Tetsuo

    2016-08-01

    Platelets are crucial components of the tumor microenvironment that function to promote tumor progression and metastasis. In the circulation, the interaction between tumor cells and platelets increases invasiveness, protects tumor cells from shear stress and immune surveillance, and facilitates tumor cell extravasation to distant sites. However, the role and presence of platelets in the primary tumor have not been fully determined. Here, we investigated the presence of platelets around breast cancer primary tumor cells and the associations between these cells. We further investigated the associations among platelets, tumor cells, chemoresistance, and epithelial-mesenchymal transition (EMT). We retrospectively analyzed data from 74 patients with human epidermal growth factor receptor 2 (HER2)‑negative breast cancer who underwent biopsies before treatment and subsequent neo-adjuvant chemotherapy. In biopsy specimens, we evaluated the expression of platelet-specific markers and EMT markers using immunohistochemistry. The associations among the expression of platelet‑specific markers in biopsy specimens, EMT, response to neo‑adjuvant chemotherapy, and survival were analyzed. The presence of platelets was observed in 44 out of 74 (59%) primary breast cancer biopsy specimens. Platelet‑positive tumor cells showed EMT‑like morphological changes and EMT marker expression. Primary tumor cells associated with platelets were less responsive to neo‑adjuvant chemotherapy (pCR rate: 10 vs. 50%, respectively; p=0.0001). Platelets were an independent predictor of the response to chemotherapy upon multivariable analysis (pbreast cancer. Platelets surrounding primary tumor cells may represent novel predictors of chemotherapeutic responses. PMID:27349611

  13. Control of cell proliferation, endoreduplication, cell size, and cell death by the retinoblastoma-related pathway in maize endosperm

    KAUST Repository

    Sabelli, Paolo A.

    2013-04-22

    The endospermof cereal grains is one of the most valuable products of modern agriculture. Cereal endosperm development comprises different phases characterized by mitotic cell proliferation, endoreduplication, the accumulation of storage compounds, and programmed cell death. Although manipulation of these processes could maximize grain yield, how they are regulated and integrated is poorly understood. We show that the Retinoblastoma-related (RBR) pathway controls key aspects of endosperm development in maize. Down-regulation of RBR1 by RNAi resulted in up-regulation of RBR3-type genes, as well as the MINICHROMOSOME MAINTENANCE 2-7 gene family and PROLIFERATING CELL NUCLEAR ANTIGEN, which encode essential DNA replication factors. Both the mitotic and endoreduplication cell cycles were stimulated. Developing transgenic endosperm contained 42-58% more cells and ~70% more DNA than wild type, whereas there was a reduction in cell and nuclear sizes. In addition, cell death was enhanced. The DNA content of mature endosperm increased 43% upon RBR1 downregulation, whereas storage protein content and kernel weight were essentially not affected. Down-regulation of both RBR1 and CYCLIN DEPENDENT KINASE A (CDKA);1 indicated that CDKA;1 is epistatic to RBR1 and controls endoreduplication through an RBR1- dependent pathway. However, the repressive activity of RBR1 on downstream targets was independent from CDKA;1, suggesting diversification of RBR1 activities. Furthermore, RBR1 negatively regulated CDK activity, suggesting the presence of a feedback loop. These results indicate that the RBR1 pathway plays a major role in regulation of different processes during maize endosperm development and suggest the presence of tissue/organlevel regulation of endosperm/seed homeostasis.

  14. Radio Frequency Magnetron Sputtering Deposition of TiO2 Thin Films and Their Perovskite Solar Cell Applications

    Science.gov (United States)

    Chen, Cong; Cheng, Yu; Dai, Qilin; Song, Hongwei

    2015-12-01

    In this work, we report a physical deposition based, compact (cp) layer synthesis for planar heterojunction perovskite solar cells. Typical solution-based synthesis of cp layer for perovskite solar cells involves low-quality of thin films, high-temperature annealing, non-flexible devices, limitation of large-scale production and that the effects of the cp layer on carrier transport have not been fully understood. In this research, using radio frequency magnetron sputtering (RFMS), TiO2 cp layers were fabricated and the thickness could be controlled by deposition time; CH3NH3PbI3 films were prepared by evaporation & immersion (E & I) method, in which PbI2 films made by thermal evaporation technique were immersed in CH3NH3I solution. The devices exhibit power conversion efficiency (PCE) of 12.1% and the photovoltaic performance can maintain 77% of its initial PCE after 1440 h. The method developed in this study has the capability of fabricating large active area devices (40 × 40 mm2) showing a promising PCE of 4.8%. Low temperature and flexible devices were realized and a PCE of 8.9% was obtained on the PET/ITO substrates. These approaches could be used in thin film based solar cells which require high-quality films leading to reduced fabrication cost and improved device performance.

  15. The Frequency of Epidermal Growth Factor Receptor Mutation of Nonsmall Cell Lung Cancer according to the Underlying Pulmonary Diseases

    Directory of Open Access Journals (Sweden)

    Kazuhiro Usui

    2011-01-01

    Full Text Available Background. Although epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs are effective in patients with nonsmall cell lung cancer with epidermal growth factor receptor (EGFR mutation, EGFR-TKIs have a risk of inducing fatal interstitial lung disease (ILD. The selection of chemotherapy based on the EGFR mutation status is recommended, however, the frequency of EGFR mutation in patients with ILD and the efficacy and safety of EGFR-TKI in patients with ILD and EGFR mutation are unknown. Methods. We retrospectively reviewed the association of the EGFR mutation status of nonsmall cell lung cancer and pulmonary diseases. Based on high-resolution computed tomography (HRCT performed at diagnosis of lung cancer, patients were categorized into three groups: normal, emphysema, and fibrosis. Results. Of 198 patients with nonsmall cell lung cancer, we identified 52 (26.3% patients with an EGFR mutation. EGFR mutations were identified in 43 (35.2% of 122 patients with normal lungs, 8 (13.6% of 59 with emphysema, and 1 (5.9% of 17 with pulmonary fibrosis. Of the 52 patients with EGFR mutation, 43 patients received gefitinib. One patient with an EGFR mutation and fibrosis developed fatal ILD. There was not a significant difference in median overall survival from gefitinib treatment between never-smokers and smokers (797 days versus not reached; =0.96. Conclusions. Patients with sensitive EGFR mutation and normal lungs may benefit from an EGFR-TKI treatment even if they have smoking history.

  16. Radio Frequency Magnetron Sputtering Deposition of TiO2 Thin Films and Their Perovskite Solar Cell Applications.

    Science.gov (United States)

    Chen, Cong; Cheng, Yu; Dai, Qilin; Song, Hongwei

    2015-12-03

    In this work, we report a physical deposition based, compact (cp) layer synthesis for planar heterojunction perovskite solar cells. Typical solution-based synthesis of cp layer for perovskite solar cells involves low-quality of thin films, high-temperature annealing, non-flexible devices, limitation of large-scale production and that the effects of the cp layer on carrier transport have not been fully understood. In this research, using radio frequency magnetron sputtering (RFMS), TiO2 cp layers were fabricated and the thickness could be controlled by deposition time; CH3NH3PbI3 films were prepared by evaporation &immersion (E &I) method, in which PbI2 films made by thermal evaporation technique were immersed in CH3NH3I solution. The devices exhibit power conversion efficiency (PCE) of 12.1% and the photovoltaic performance can maintain 77% of its initial PCE after 1440 h. The method developed in this study has the capability of fabricating large active area devices (40 × 40 mm(2)) showing a promising PCE of 4.8%. Low temperature and flexible devices were realized and a PCE of 8.9% was obtained on the PET/ITO substrates. These approaches could be used in thin film based solar cells which require high-quality films leading to reduced fabrication cost and improved device performance.

  17. Delayed SCE frequency of rat bone marrow cells after radon inhalation

    International Nuclear Information System (INIS)

    Cytogenetic tests can reflect in vivo cellular modifications during development of induced neoplasic lesions. These last years, a new experimental in vivo cytogenetic test has been widely developed: Sister chromatid exchanges (SCE) especially on bone marrow cells. This study establishes the relationships between SCE in the bone marrow of rat and post exposure time following whole body neutron irradiation and radon inhalation. From the observed data a two stages response is pointed out. The first stage is thought to correspond to direct DNA damage and is characterized by a short term increase of bone marrow SCE followed by a rapid decrease up to the control values. The second one is marked by a delayed increase of SCE followed by a plateau significantly higher than the control values. From neutron radon exposure and from previously observed data this second stage strongly suggests a modification of the whole organism induced by 'mutagen/carcinogen' modified target organs

  18. Power Spectrum of Out-of-equilibrium Forces in Living Cells : Amplitude and Frequency Dependence

    CERN Document Server

    Gallet, Francois; Bohec, Pierre; Richert, Alain

    2009-01-01

    Living cells exhibit an important out-of-equilibrium mechanical activity, mainly due to the forces generated by molecular motors. These motor proteins, acting individually or collectively on the cytoskeleton, contribute to the violation of the fluctuation-dissipation theorem in living systems. In this work we probe the cytoskeletal out-of-equilibrium dynamics by performing simultaneous active and passive microrheology experiments, using the same micron-sized probe specifically bound to the actin cortex. The free motion of the probe exhibits a constrained, subdiffusive behavior at short time scales (t < 2s), and a directed, superdiffusive behavior at larger time scales, while, in response to a step force, its creep function presents the usual weak power law dependence with time. Combining the results of both experiments, we precisely measure for the first time the power spectrum of the force fluctuations exerted on this probe, which lies more than one order of magnitude above the spectrum expected at equili...

  19. High frequency of p53 intronic point mutations in laryngeal squamous cell carcinoma

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xu; LI Fucai; SONG Yutong; LI Yinghui; FU Weineng; XU Zhenming; SUN Kailai

    2004-01-01

    Intronic point mutations are rare and totally unknown for human laryngeal squamous cell carcinoma (LSCC). To explore the relationship of p53 gene intronic mutation to the development of human LSCC, DNA was extracted from both tumor tissues and matched normal tissues of 55 patients with LSCC in northeast of China. Polymerase chain reaction amplification-single strand conformational polymorphism (PCR-SSCP) combined with silver staining and DNA direct sequencing were used to detect mutations in exons 7~8 (p53E7 and p53E8) and introns 7~8 (p53I7 and p53I8) of p53 gene. The p53E7 mutation was detected in 17 out of 55 patients, and the p53I7 mutation in 21 patients. No mutation was found at p53E8 or p53I8 site. The difference between tumor group and paired normal group on the rates of both p53E7 and p53I7 mutations was statistically significant. The rate of p53I7 mutations in tumor tissue was higher than that of normal tissue, and so was that of p53E7. Sequence analysis revealed that most p53I7 mutations were at the nucleotides in the branch point sequence or the polypyrimidine tract in the 3′-splice acceptor site of the intron 7. The high incidence of p53 gene intronic mutation in LSCC indicates that genetic changes within the noncoding region of the p53 gene may serve as an alternative mechanism of activating the pathogenesis of human laryngeal squamous cell carcinoma. Mutations in the noncoding region of this gene should be further studied.

  20. Low frequency, electrodynamic simulation of kinetic plasmas with the DArwin Direct Implicit Particle-In-Cell (DADIPIC) method

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, M.R.

    1995-06-01

    This dissertation describes a new algorithm for simulating low frequency, kinetic phenomena in plasmas. DArwin Direct Implicit Particle-in-Cell (DADIPIC), as its name implies, is a combination of the Darwin and direct implicit methods. One of the difficulties in simulating plasmas lies in the enormous disparity between the fundamental scale lengths of a plasma and the scale lengths of the phenomena of interest. The objective is to create models which can ignore the fundamental constraints without eliminating relevant plasma properties. Over the past twenty years several PIC methods have been investigated for overcoming the constraints on explicit electrodynamic PIC. These models eliminate selected high frequency plasma phenomena while retaining kinetic phenomena at low frequency. This dissertation shows that the combination of Darwin and Direct Implicit allows them to operate better than they have been shown to operate in the past. Through the Darwin method the hyperbolic Maxwell`s equations are reformulated into a set of elliptic equations. Propagating light waves do not exist in the formulation so the Courant constraint on the time step is eliminated. The Direct Implicit method is applied only to the electrostatic field with the result that electrostatic plasma oscillations do not have to be resolved for stability. With the elimination of these constraints spatial and temporal discretization can be much larger than that possible with explicit, electrodynamic PIC. The code functions in a two dimensional Cartesian region and has been implemented with all components of the particle velocities, the E-field, and the B-field. Internal structures, conductors or dielectrics, may be placed in the simulation region, can be set at desired potentials, and driven with specified currents.

  1. Discovery of the cancer stem cell related determinants of radioresistance

    International Nuclear Information System (INIS)

    Tumors are known to be heterogeneous containing a dynamic mixture of phenotypically and functionally different tumor cells. The two concepts attempting to explain the origin of intratumor heterogeneity are the cancer stem cell hypothesis and the clonal evolution model. The stochastic model argues that tumors are biologically homogenous and all cancer cells within the tumor have equal ability to propagate the tumor growth depending on continuing mutations and selective pressure. By contrast, the stem cells model suggests that cancer heterogeneity is due to the hierarchy that originates from a small population of cancer stem cells (CSCs) which are biologically distinct from the bulk tumor and possesses self-renewal, tumorigenic and multilineage potential. Although these two hypotheses have been discussed for a long time as mutually exclusive explanations of tumor heterogeneity, they are easily reconciled serving as a driving force of cancer evolution and diversity. Recent discovery of the cancer cell plasticity and heterogeneity makes the CSC population a moving target that could be hard to track and eradicate. Understanding the signaling mechanisms regulating CSCs during the course of cancer treatment can be indispensable for the optimization of current treatment strategies

  2. Meningitis Caused by Toscana Virus Is Associated with Strong Antiviral Response in the CNS and Altered Frequency of Blood Antigen-Presenting Cells

    Directory of Open Access Journals (Sweden)

    Stefania Varani

    2015-11-01

    Full Text Available Toscana virus (TOSV is a Phlebotomus-transmitted RNA virus and a frequent cause of human meningitis and meningoencephalitis in Southern Europe during the summer season. While evidence for TOSV-related central nervous system (CNS cases is increasing, little is known about the host defenses against TOSV. We evaluated innate immune response to TOSV by analyzing frequency and activation of blood antigen-presenting cells (APCs and cytokine levels in plasma and cerebrospinal fluid (CSF from patients with TOSV neuroinvasive infection and controls. An altered frequency of different blood APC subsets was observed in TOSV-infected patients, with signs of monocytic deactivation. Nevertheless, a proper or even increased responsiveness of toll-like receptor 3 and 7/8 was observed in blood APCs of these patients as compared to healthy controls. Systemic levels of cytokines remained low in TOSV-infected patients, while levels of anti-inflammatory and antiviral mediators were significantly higher in CSF from TOSV-infected patients as compared to patients with other infectious and noninfectious neurological diseases. Thus, the early host response to TOSV appears effective for viral clearance, by proper response to TLR3 and TLR7/8 agonists in peripheral blood and by a strong and selective antiviral and anti-inflammatory response in the CNS.

  3. Stroma cell-derived factor-1α signaling enhances calcium transients and beating frequency in rat neonatal cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Ielham Hadad

    Full Text Available Stroma cell-derived factor-1α (SDF-1α is a cardioprotective chemokine, acting through its G-protein coupled receptor CXCR4. In experimental acute myocardial infarction, administration of SDF-1α induces an early improvement of systolic function which is difficult to explain solely by an anti-apoptotic and angiogenic effect. We wondered whether SDF-1α signaling might have direct effects on calcium transients and beating frequency.Primary rat neonatal cardiomyocytes were culture-expanded and characterized by immunofluorescence staining. Calcium sparks were studied by fluorescence microscopy after calcium loading with the Fluo-4 acetoxymethyl ester sensor. The cardiomyocyte enriched cellular suspension expressed troponin I and CXCR4 but was vimentin negative. Addition of SDF-1α in the medium increased cytoplasmic calcium release. The calcium response was completely abolished by using a neutralizing anti-CXCR4 antibody and partially suppressed and delayed by preincubation with an inositol triphosphate receptor (IP3R blocker, but not with a ryanodine receptor (RyR antagonist. Calcium fluxes induced by caffeine, a RyR agonist, were decreased by an IP3R blocker. Treatment with forskolin or SDF-1α increased cardiomyocyte beating frequency and their effects were additive. In vivo, treatment with SDF-1α increased left ventricular dP/dtmax.These results suggest that in rat neonatal cardiomyocytes, the SDF-1α/CXCR4 signaling increases calcium transients in an IP3-gated fashion leading to a positive chronotropic and inotropic effect.

  4. On the estimation of high frequency parameters of Proton Exchange Membrane Fuel Cells via Electrochemical Impedance Spectroscopy

    Science.gov (United States)

    Mainka, J.; Maranzana, G.; Dillet, J.; Didierjean, S.; Lottin, O.

    2014-05-01

    This paper is a discussion on the estimation of impedance parameters of H2/air fed Proton Exchange Membrane Fuel Cells (PEMFC). The impedance model corresponds to the Randles electrical equivalent circuit accounting for charge separation and transport processes in the cathode catalyst layer, as well as for oxygen diffusion through the backing layer. A sensitivity analysis confirms that the cathode parameters are not correlated and that the consideration of the anode has no significant impact on the estimation of their values. In addition, it is shown that the diffusion parameters have a significant impact in the low frequency domain only, at least with this model. The parameters characterizing charge separation and transport processes at the cathode can thus be estimated with the high frequency impedance data, independently of the oxygen transport model. Consequently, even in the absence of a fully validated oxygen transport impedance, EIS can be used as an alternative method (to classical steady-state methods) for the estimation of the parameters characterizing the cathode reaction: the Tafel slope b, the charge transfer coefficient α and possibly, the exchange current density j0. This reduces significantly the measuring time while enhancing the accuracy by comparison with steady-state methods.

  5. The Fabrication of Flow Field Plates for Direct Methanol Fuel Cell Using Lithography and Radio Frequency Sputtering.

    Science.gov (United States)

    Chang, Ho; Kao, Mu-Jung; Chen, Chih-Hao; Cho, Kun-Ching; Hsu, Chun-Yao; Chen, Zhi-Lun

    2015-08-01

    This study uses lithography to etch flow fields on a single side of a printed circuit board (PCB) and combines a flow field plate with a collector plate to make innovative anode flow field plates and cathode flow field plates for a direct methanol fuel cell (DMFC). TiO2 thin film is also sputtered on the anode flow field plate using radio frequency (RF) sputtering. The experimental results show that the prepared DMFC has a better maximum power density of 11.928 mW/cm2. Furthermore, when a TiO2 thin film is sputtered on the flow field plate of the assembled DMFC, the maximum power density is 14.426 mW/cm2, which is actually 21% more than that for a DMFC with no TiO2 thin film coated on the flow field plate.

  6. Non-B DNA-forming sequences and WRN deficiency independently increase the frequency of base substitution in human cells

    DEFF Research Database (Denmark)

    Bacolla, Albino; Wang, Guliang; Jain, Aklank;

    2011-01-01

    the mutation frequency, the increase afforded by WRN-KD was independent of DNA structure despite the fact that purified WRN helicase was found to resolve these structures in vitro. In U2OS cells, ~70% of mutations comprised single-base substitutions, mostly at G·C base-pairs, with the remaining ~30% being...... microdeletions. The number of mutations at G·C base-pairs in the context of NGNN/NNCN sequences correlated well with predicted free energies of base stacking and ionization potentials, suggesting a possible origin via oxidation reactions involving electron loss and subsequent electron transfer (hole migration......) between neighboring bases. A set of ~40,000 somatic mutations at G·C base pairs identified in a lung cancer genome exhibited similar correlations, implying that hole migration may also be involved. We conclude that alternative DNA conformations, WRN deficiency and lung tumorigenesis may all serve...

  7. Microcrystalline silicon from very high frequency plasma deposition and hot-wire CVD for ``micromorph`` tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Brummack, H.; Brueggemann, R.; Wanka, H.N.; Hierzenberger, A.; Schubert, M.B. [Univ. Stuttgart (Germany). Inst. fuer Physikalische Elektronik

    1997-12-31

    The authors have grown microcrystalline silicon from a glow discharge at very high frequencies of 55 MHz and 170 MHz with high hydrogen dilution, and also, at more than 10 times higher growth rates, similar films by hot-wire chemical vapor deposition. Both kinds of materials have extensively been characterized and compared in terms of structural, optical and electronic properties, which greatly improve by deposition in a multi- instead of a single-chamber system. Incorporation of these different materials into pin solar cells results in open circuit voltages of about 400 mV as long as the doped layers are microcrystalline and rise to more than 870 mV if amorphous p- and n-layers are used. Quantum efficiencies and fill factors are still poor but leave room for further improvement, as clearly demonstrated by a remarkable reverse bias quantum efficiency gain.

  8. COUPLING EFFECTS FOR CELL-TRUSS SPAR PLATFORM: COMPARISON OF FREQUENCY- AND TIME-DOMAIN ANALYSES WITH MODEL TESTS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fan; YANG Jian-min; LI Run-pei; CHEN Gang

    2008-01-01

    For the floating structures in deepwater, the coupling effects of the mooring lines and risers on the motion responses of the structures become increasingly significant. Viscous damping, inertial mass, current loading and restoring, etc. from these slender structures should be carefully handled to accurately predict the motion responses and line tensions. For the spar platforms, coupling the mooring system and riser with the vessel motion typically results in a reduction in extreme motion responses. This article presents numerical simulations and model tests on a new cell-truss spar platform in the State Key Laboratory of Ocean Engineering in Shanghai Jiaotong University. Results from three calculation methods, including frequency-domain analysis, time-domain semi-coupled and fully-coupled analyses, were compared with the experimental data to find the applicability of different approaches. Proposals for the improvement of numerical calculations and experimental technique were tabled as well.

  9. A novel method for sensing metastatic cells in the CSF of pediatric population with medulloblastoma by frequency domain FLIM system

    Science.gov (United States)

    Yahav, Gilad; Fixler, Dror; Gershanov, Sivan; Goldenberg-Cohen, Nitza

    2016-03-01

    Brain tumors are the second leading cause of cancer-related deaths in children, after leukemia. Patients with cancer in the central nervous system have a very low recovery rate. Today known imaging and cytology techniques are not always sensitive enough for an early detection of both tumor and its metastatic spread, moreover the detection is generally limited, reviewer dependent and takes a relatively long time. Medulloblastoma (MB) is the most common malignant brain tumor in children. The aim of our talk is to present the frequency domain fluorescence lifetime imaging microscopy system as a possible method for an early detection of MB and its metastatic spread in the cerebrospinal fluids within the pediatric population.

  10. Antifungal Pisum sativum defensin 1 interacts with Neurospora crassa cyclin F related to the cell cycle.

    Science.gov (United States)

    Lobo, Denise S; Pereira, Iuri B; Fragel-Madeira, Lucianne; Medeiros, Luciano N; Cabral, Luiz M; Faria, Jane; Bellio, Maria; Campos, Reinaldo C; Linden, Rafael; Kurtenbach, Eleonora

    2007-01-30

    Plant defensins, components of the plant innate immune system, are cationic cysteine-rich antifungal peptides. Evidence from the literature [Thevissen, K., et al. (2003) Peptides 24, 1705-1712] has demonstrated that patches of fungi membrane containing mannosyldiinositolphosphorylceramide and glucosylceramides are selective binding sites for the plant defensins isolated from Dahlia merckii and Raphanus sativus, respectively. Whether plant defensins interact directly or indirectly with fungus intracellular targets is unknown. To identify physical protein-protein interactions, a GAL4-based yeast two-hybrid system was performed using the antifungal plant peptide Pisum sativum defensin 1 (Psd1) as the bait. Target proteins were screened within a Neurospora crassa cDNA library. Nine out of 11 two-hybrid candidates were nuclear proteins. One clone, detected with high frequency per screening, presented sequence similarity to a cyclin-like protein, with F-box and WD-repeat domains, related to the cell cycle control. GST pull-down assay corroborated in vitro this two-hybrid interaction. Fluorescence microscopy analysis of FITC-conjugated Psd1 and DAPI-stained fungal nuclei showed in vivo the colocalization of the plant peptide Psd1 and the nucleus. Analysis of the DNA content of N. crassa conidia using flow cytometry suggested that Psd1 directed cell cycle impairment and caused conidia to undergo endoreduplication. The developing retina of neonatal rats was used as a model to observe the interkinetic nuclear migration during proliferation of an organized tissue from the S toward the M phase of the cell cycle in the presence of Psd1. The results demonstrated that the plant defensin Psd1 regulates interkinetic nuclear migration in retinal neuroblasts. PMID:17240982

  11. Autocorrelation standard deviation and root mean square frequency analysis of polymer electrolyte membrane fuel cell to monitor for hydrogen and air undersupply

    Science.gov (United States)

    Kim, Joo Gon; Mukherjee, Santanu; Bates, Alex; Zickel, Benjamin; Park, Sam; Son, Byung Rak; Choi, Jae Sung; Kwon, Osung; Lee, Dong Ha; Chung, Hyun-Youl

    2015-12-01

    Proton exchange membrane fuel cells are a promising energy conversion device which can help to solve urgent environmental and economic problems. Among the various types of fuel cells, the air breathing proton exchange membrane fuel cell, which minimizes the balance of plant, has drawn a lot of attention due to its superior energy density. In this study a compact, air breathing, proton exchange membrane fuel cell based on Nafion and a Pt/C membrane electrode assembly was designed. The fuel cell was tested using a Scribner Associates 850e fuel cell test station. Specifically, the hydrogen fuel and oxygen starvation of the fuel cell were accurately and systematically tested and analyzed using a frequency analysis method which can analyze the input and output frequency. The analysis of the frequency variation under a fuel starvation condition was done using RMSF (root mean square frequency) and ACSD (autocorrelation standard deviation). The study reveals two significant results: first, the fuel starvations show entirely different phenomenon in both RMSF and ACSD and second, the results of the Autocorrelation show clearer results for fuel starvation detection than the results with RMSF.

  12. 1-eV GaInNAs solar cells for ultrahigh-frequency multijunction devices

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, D.J.; Geisz, J.F.; Kurtz, S.R.; Olson, J.M. [National Renewable Energy Lab., Golden, CO (United States)

    1998-09-01

    The authors demonstrate working prototypes of a GaInNAs-based solar cell lattice-matched to GaAs with photoresponse down to 1 eV. This device is intended for use as the third junction of future-generation ultrahigh-efficiency three- and four-junction devices. Under the AM1.5 direct spectrum with all the light higher in energy than the GaAs band gap filtered out, the prototypes have open-circuit voltages ranging from 0.35 to 0.44 V, short-circuit currents of 1.8 mA/cm{sup 2}, and fill factors from 61--66%. The short-circuit currents are of principal concern: the internal quantum efficiencies rise only to about 0.2. The authors discuss the short diffusion lengths which are the reason for this low photocurrent. As a partial workaround for the poor diffusion lengths, they demonstrate a depletion-width-enhanced variation of one of the prototype devices that grades off decreased voltage for increased photocurrent, with a short-circuit current of 6.5 mA/cm{sup 2} and an open-circuit voltage of 0.29 V.

  13. Increased protein synthesis by cells exposed to a 1,800-MHz radio-frequency mobile phone electromagnetic field, detected by proteome profiling

    OpenAIRE

    Gerner, Christopher; Haudek, Verena; Schandl, Ulla; Bayer, Editha; Gundacker, Nina; Hutter, Hans Peter; Mosgoeller, Wilhelm

    2010-01-01

    Purpose To investigate whether or not low intensity radio frequency electromagnetic field exposure (RF-EME) associated with mobile phone use can affect human cells, we used a sensitive proteome analysis method to study changes in protein synthesis in cultured human cells. Methods Four different cell kinds were exposed to 2 W/kg specific absorption rate in medium containing 35S-methionine/cysteine, and autoradiography of 2D gel spots was used to measure the increased synthesis of individual pr...

  14. Frequencies and Specificities of “Enzyme-Only” Detected Erythrocyte Alloantibodies in Patients Hospitalized in Austria: Is an Enzyme Test Required for Routine Red Blood Cell Antibody Screening?

    OpenAIRE

    Dietmar Enko; Claudia Habres; Franz Wallner; Barbara Mayr; Gabriele Halwachs-Baumann

    2014-01-01

    The aim of this study was to determine the frequencies and specificities of “enzyme-only” detected red blood cell (RBC) alloantibodies in the routine antibody screening and antibody identification in patients hospitalized in Austria. Routine blood samples of 2420 patients were investigated. The antibody screening was performed with a 3-cell panel in the low-ionic strength saline- (LISS-) indirect antiglobulin test (IAT) and with an enzyme-pretreated (papain) 3-cell panel fully automated on th...

  15. THE CHARACTERISTICS OF THUNDERSTORM FREQUENCY VARIATION AND THEIR POSSIBLE RELATION WITH THE ADJUSTMENT OF CROP DISTRIBUTION IN THE LEIZHOU PENINSULA

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu; NIU Sheng-jie

    2009-01-01

    In order to research possible influences of the adjustment of plant distribution on the development frequency of thunderstorms over the Leizhou Peninsula,mathematic statistic methods, including correlation analyses,11 kinds of fitting models and all-variable regression methods,were used for analyses and research. The results show that the average trend of the number of annual thunderstorm days is descending obviously,and there are thunderstorms in all seasons,in which warm post-midday thunderstorms have taken up the most part,and high frequency is found from May to September,and the starting and ending dates of thunderstorms have a great annual discrepancy. The vegetation structure has been improved along with the reduction of rice fields and the area increment of sugarcane and fruits planting,which results in the decrease of the number of thunderstorm days; the change in the characteristics of winter spare fields,which is caused by the planting of vegetables,limits the formation of thunderstorms in early winter and late spring. Meanwhile,the area adjustment of peanut planting has little influence on the variation of thunderstorm days. The adjustment of principal crop distribution,such as rice, sugarcane,fruits and vegetables,may have obvious influence on the formation of thunderstorms,and sugarcane has the largest effect,followed in turn by rice,vegetables and fruits,and the adjustment of crop distribution has little influence on the starting and ending dates of thunderstorms.

  16. Analysis of cytotoxic T cell epitopes in relation to cancer

    DEFF Research Database (Denmark)

    Stranzl, Thomas

    CTL methods, the experimental effort to identify 90% of new epitopes can be reduced by 15% and 40%, respectively. Part III reports the results of an analysis investigating how the alternatively spliced cancer exome differs from the exome of normal tissue in terms of containing predicted MHC class I binding....... Part IV of the thesis deals with the analysis of 93 patient-donor pairs that underwent hematopoietic stem cell transplantation (HCT). HCT is a standard treatment for a variety of hematological diseases. Graft-versus-host disease is a possible complication after an HCT, where the recipient´s cells...

  17. Event-related brain potentials to change in the frequency and temporal structure of sounds in typically developing 5-6-year-old children.

    Science.gov (United States)

    Ervast, Leena; Hämäläinen, Jarmo A; Zachau, Swantje; Lohvansuu, Kaisa; Heinänen, Kaisu; Veijola, Mari; Heikkinen, Elisa; Suominen, Kalervo; Luotonen, Mirja; Lehtihalmes, Matti; Leppänen, Paavo H T

    2015-12-01

    The brain's ability to recognize different acoustic cues (e.g., frequency changes in rapid temporal succession) is important for speech perception and thus for successful language development. Here we report on distinct event-related potentials (ERPs) in 5-6-year-old children recorded in a passive oddball paradigm to repeated tone pair stimuli with a frequency change in the second tone in the pair, replicating earlier findings. An occasional insertion of a third tone within the tone pair generated a more merged pattern, which has not been reported previously in 5-6-year-old children. Both types of deviations elicited pre-attentive discriminative mismatch negativity (MMN) and late discriminative negativity (LDN) responses. Temporal principal component analysis (tPCA) showed a similar topographical pattern with fronto-central negativity for MMN and LDN. We also found a previously unreported discriminative response complex (P340-N440) at the temporal electrode sites at about 140 ms and 240 ms after the frequency deviance, which we suggest reflects a discriminative processing of frequency change. The P340 response was positive with a clear radial distribution preceding the fronto-central frequency MMN by about 30 ms. The results indicate that 5-6-year-old children can detect frequency change and the occasional insertion of an additional tone in sound pairs as reflected by MMN and LDN, even with quite short within-stimulus intervals (150 ms and 50 ms). Furthermore, MMN for these changes is preceded by another response to deviancy, temporal P340, which seems to reflect a parallel but earlier discriminatory process. PMID:26342552

  18. Age-Related Enhancement of a Protein Synthesis-Dependent Late Phase of LTP Induced by Low Frequency Paired-Pulse Stimulation in Hippocampus

    Science.gov (United States)

    Huang, Yan-You; Kandel, Eric R.

    2006-01-01

    Protein synthesis-dependent late phase of LTP (L-LTP) is typically induced by repeated high-frequency stimulation (HFS). This form of L-LTP is reduced in the aged animal and is positively correlated with age-related memory loss. Here we report a novel form of protein synthesis-dependent late phase of LTP in the CA1 region of hippocampus induced by…

  19. Contribution of T Cell Subsets to the Pathophysiology of Pneumocystis-Related Immunorestitution Disease

    OpenAIRE

    Samir P Bhagwat; Gigliotti, Francis; Xu, Haodong; Wright, Terry W.

    2006-01-01

    Immune-mediated lung injury is an important component of Pneumocystis pneumonia (PcP)-related immunorestitution disease (IRD). However, the individual contribution of CD4+ and CD8+ T cells to the pathophysiology of IRD remains undetermined. Therefore, IRD was modeled in severe combined immunodeficient mice, and specific T cell depletion was used to determine how T cell subsets interact to affect the nature and severity of disease. CD4+ cells were more abundant than CD8+ cells during the acute...

  20. Sickle Cell Disease Pain: Relation of Coping Strategies to Adjustment.

    Science.gov (United States)

    Gil, Karen M.; And Others

    1989-01-01

    Examined pain coping strategies in 79 adult sickle cell disease (SCD) patients. Results revealed that coping strategies factors were important predictors of pain and adjustment. Subjects high on Negative Thinking and Passive Adherence had more severe pain, were less active and more distressed, and used more health services. Individuals high on…

  1. Stem cells and neurogenesis in relation to Alzheimer's disease Models

    NARCIS (Netherlands)

    P.J. Lucassen; E.H. Jacobs; L. Hoeijmakers; S.L. Lesuis; H. Krugers; A. Korosi; H.G. Kuhn; K. Boekhoorn

    2015-01-01

    Alzheimer’s disease (AD) is a devastating neurodegenerative disorder associated with progressive cognitive decline and extensive neuropathology throughout the brain. Its main features include limited cell loss in selected subregions, generalized brain atrophy, and gradual accumulation of β-amyloid p

  2. Modeling of Red Blood Cells and Related Spleen Function

    Science.gov (United States)

    Peng, Zhangli; Pivkin, Igor; Dao, Ming

    2011-11-01

    A key function of the spleen is to clear red blood cells (RBCs) with abnormal mechanical properties from the circulation. These abnormal mechanical properties may be due to RBC aging or RBC diseases, e.g., malaria and sickle cell anemia. Specifically, 10% of RBCs passing through the spleen are forced to squeeze into the narrow slits between the endothelial cells, and stiffer cells which get stuck are killed and digested by macrophages. To investigate this important physiological process, we employ three different approaches to study RBCs passage through these small slits, including analytical theory, Dissipative Particle Dynamics (DPD) simulation and Multiscale Finite Element Method (MS-FEM). By applying the analytical theory, we estimate the critical limiting geometries RBCs can pass. By using the DPD method, we study the full fluid-structure interaction problem, and compute RBC deformation under different pressure gradients. By employing the MS-FEM approach, we model the lipid bilayer and the cytoskeleton as two distinct layers, and focus on the cytoskeleton deformation and the bilayer-skeleton interaction force at the molecular level. Finally the results of these three approaches are compared to each other and correlated to the experimental observations.

  3. Age-related changes in murine T cell function

    NARCIS (Netherlands)

    C.S. Vissinga (Christine)

    1988-01-01

    textabstractThe aim of the studies presented here was to obtain a more detailed and integrated picture of the age-related changes in cellular immunity. The age-related changes of cellular immunity were studied by in vivo induction of DTH responses to a variety of antigens (Chapters 2 and 3). The res

  4. 7 CFR 58.336 - Frequency of sampling for quality control of cream, butter and related products.

    Science.gov (United States)

    2010-01-01

    ..., butter and related products. 58.336 Section 58.336 Agriculture Regulations of the Department of... of sampling for quality control of cream, butter and related products. (a) Microbiological. Samples... from the butter as often as is necessary to aid in the control of lipase activity. (d) Other...

  5. Individualism and socioeconomic diversity at school as related to perceptions of the frequency of peer aggression in fifteen countries.

    Science.gov (United States)

    Menzer, Melissa M; Torney-Purta, Judith

    2012-10-01

    The purpose of this study was to examine two aspects of context for peer aggression: national individualism and distributions of socioeconomic status in the school. School administrators for each school reported on their perceptions of the frequency of bullying and violence in their school. The sample comprised 990 school principals/headmasters from nationally representative samples of schools in 15 countries surveyed as part of the larger IEA Civic Education Study (Torney-Purta, Lehmann, Oswald, & Schulz, 2001). A national context of individualism was associated with violence but not bullying. Schools with high socioeconomic diversity had more bullying than homogeneously low or high socioeconomic status schools. In addition, diverse schools had more violence than affluent schools. Results suggest that bullying and violence should be investigated as separate constructs. Furthermore, contexts, such as national culture and school socioeconomic diversity, are important in understanding the prevalence of bullying and violence in schools internationally.

  6. A preliminary report relating frequency of vaginal intercourse to heart rate variability, Valsalva ratio, blood pressure, and cohabitation status.

    Science.gov (United States)

    Brody, S; Veit, R; Rau, H

    2000-04-01

    The relationship between recalled frequency of penile-vaginal intercourse (FSI) and resting heart rate variability (HRV; an index of parasympathetic tone), resting diastolic blood pressure (DBP) and heart rate (HR) response to the Valsalva maneuver was examined in 51 healthy adults aged 20-47 (subjects scoring above the 86th percentile on the Lie scale of the Eysenck Personality Inventory (EPI) were excluded). As hypothesized, greater HRV and lower DBP were both associated with greater FSI (but not masturbation or non-coital sex with a partner) in cohabiting subjects, but not in non-cohabiting subjects. Valsalva ratio was unrelated to sexual behavior. Results are discussed in terms of both the modulating role of blood pressure on a number of psychological functions and the role of parasympathetic tone in HRV, FSI, and possibly pair-bonding. PMID:10725567

  7. Age-related prevalence, intensity and frequency distribution of gastrointestinal helminth infection in urban slum children from Kuala Lumpur, Malaysia.

    Science.gov (United States)

    Bundy, D A; Kan, S P; Rose, R

    1988-01-01

    The gastrointestinal helminth infection status of 1574 children living in a slum area of Kuala Lumpur, Malaysia was assessed by quantitative coprology. Almost two-thirds were infected with Trichuris trichiura, 49.6% with Ascaris lumbricoides, and 5.3% with hookworm. Infection prevalence rose rapidly to a stable asymptote at 7 years of age, and the age-intensity profile was convex with maximal values in the 5-10 year age classes. This pattern was the same for males and females, but differed markedly between different ethnic groups. The frequency distributions of A. lumbricoides and T. trichiura were highly overdispersed (k values were 0.21 and 0.27, respectively), and age-dependent over the 0-8 year age classes. This suggests that the force of infection with these nematodes is lower in infants than in older children.

  8. Simple-design ultra-low phase noise microwave frequency synthesizers for high-performing Cs and Rb vapor-cell atomic clocks

    International Nuclear Information System (INIS)

    We report on the development and characterization of novel 4.596 GHz and 6.834 GHz microwave frequency synthesizers devoted to be used as local oscillators in high-performance Cs and Rb vapor-cell atomic clocks. The key element of the synthesizers is a custom module that integrates a high spectral purity 100 MHz oven controlled quartz crystal oscillator frequency-multiplied to 1.6 GHz with minor excess noise. Frequency multiplication, division, and mixing stages are then implemented to generate the exact output atomic resonance frequencies. Absolute phase noise performances of the output 4.596 GHz signal are measured to be −109 and −141 dB rad2/Hz at 100 Hz and 10 kHz Fourier frequencies, respectively. The phase noise of the 6.834 GHz signal is −105 and −138 dB rad2/Hz at 100 Hz and 10 kHz offset frequencies, respectively. The performances of the synthesis chains contribute to the atomic clock short term fractional frequency stability at a level of 3.1 × 10−14 for the Cs cell clock and 2 × 10−14 for the Rb clock at 1 s averaging time. This value is comparable with the clock shot noise limit. We describe the residual phase noise measurements of key components and stages to identify the main limitations of the synthesis chains. The residual frequency stability of synthesis chains is measured to be at the 10−15 level for 1 s integration time. Relevant advantages of the synthesis design, using only commercially available components, are to combine excellent phase noise performances, simple-architecture, low-cost, and to be easily customized for signal output generation at 4.596 GHz or 6.834 GHz for applications to Cs or Rb vapor-cell frequency standards

  9. Simple-design ultra-low phase noise microwave frequency synthesizers for high-performing Cs and Rb vapor-cell atomic clocks

    Energy Technology Data Exchange (ETDEWEB)

    François, B. [FEMTO-ST, CNRS, Université de Franche-Comté, 26 chemin de l’Epitaphe, 25030 Besançon (France); INRIM, Strada delle Cacce 91, 10135 Torino (Italy); Calosso, C. E.; Micalizio, S. [INRIM, Strada delle Cacce 91, 10135 Torino (Italy); Abdel Hafiz, M.; Boudot, R. [FEMTO-ST, CNRS, Université de Franche-Comté, 26 chemin de l’Epitaphe, 25030 Besançon (France)

    2015-09-15

    We report on the development and characterization of novel 4.596 GHz and 6.834 GHz microwave frequency synthesizers devoted to be used as local oscillators in high-performance Cs and Rb vapor-cell atomic clocks. The key element of the synthesizers is a custom module that integrates a high spectral purity 100 MHz oven controlled quartz crystal oscillator frequency-multiplied to 1.6 GHz with minor excess noise. Frequency multiplication, division, and mixing stages are then implemented to generate the exact output atomic resonance frequencies. Absolute phase noise performances of the output 4.596 GHz signal are measured to be −109 and −141 dB rad{sup 2}/Hz at 100 Hz and 10 kHz Fourier frequencies, respectively. The phase noise of the 6.834 GHz signal is −105 and −138 dB rad{sup 2}/Hz at 100 Hz and 10 kHz offset frequencies, respectively. The performances of the synthesis chains contribute to the atomic clock short term fractional frequency stability at a level of 3.1 × 10{sup −14} for the Cs cell clock and 2 × 10{sup −14} for the Rb clock at 1 s averaging time. This value is comparable with the clock shot noise limit. We describe the residual phase noise measurements of key components and stages to identify the main limitations of the synthesis chains. The residual frequency stability of synthesis chains is measured to be at the 10{sup −15} level for 1 s integration time. Relevant advantages of the synthesis design, using only commercially available components, are to combine excellent phase noise performances, simple-architecture, low-cost, and to be easily customized for signal output generation at 4.596 GHz or 6.834 GHz for applications to Cs or Rb vapor-cell frequency standards.

  10. Extremely low-frequency electromagnetic fields enhance the proliferation and differentiation of neural progenitor cells cultured from ischemic brains.

    Science.gov (United States)

    Cheng, Yannan; Dai, Yiqin; Zhu, Ximin; Xu, Haochen; Cai, Ping; Xia, Ruohong; Mao, Lizhen; Zhao, Bing-Qiao; Fan, Wenying

    2015-10-21

    In the mammalian brain, neurogenesis persists throughout the embryonic period and adulthood in the subventricular zone of the lateral ventricle and the granular zone (dentate gyrus) of the hippocampus. Newborn neural progenitor cells (NPCs) in the two regions play a critical role in structural and functional plasticity and neural regeneration after brain injury. Previous studies have reported that extremely low-frequency electromagnetic fields (ELF-EMF) could promote osteogenesis, angiogenesis, and cardiac stem cells' differentiation, which indicates that ELF-EMF might be an effective tool for regenerative therapy. The present studies were carried out to examine the effects of ELF-EMF on hippocampal NPCs cultured from embryonic and adult ischemic brains. We found that exposure to ELF-EMF (50 Hz, 0.4 mT) significantly enhanced the proliferation capability both in embryonic NPCs and in ischemic NPCs. Neuronal differentiation was also enhanced after 7 days of cumulative ELF-EMF exposure, whereas glial differentiation was not influenced markedly. The expression of phosphorylated Akt increased during the proliferation process when ischemic NPCs were exposed to ELF-EMF. However, blockage of the Akt pathway abolished the ELF-EMF-induced proliferation of ischemic NPCs. These data show that ELF-EMF promotes neurogenesis of ischemic NPCs and suggest that this effect may occur through the Akt pathway.Video abstract, Supplemental Digital Content 1, http://links.lww.com/WNR/A347. PMID:26339991

  11. Time related variations in stem cell harvesting of umbilical cord blood

    Science.gov (United States)

    Mazzoccoli, Gianluigi; Miscio, Giuseppe; Fontana, Andrea; Copetti, Massimiliano; Francavilla, Massimo; Bosi, Alberto; Perfetto, Federico; Valoriani, Alice; de Cata, Angelo; Santodirocco, Michele; Totaro, Angela; Rubino, Rosa; di Mauro, Lazzaro; Tarquini, Roberto

    2016-02-01

    Umbilical cord blood (UCB) contains hematopoietic stem cells and multipotent mesenchymal cells useful for treatment in malignant/nonmalignant hematologic-immunologic diseases and regenerative medicine. Transplantation outcome is correlated with cord blood volume (CBV), number of total nucleated cells (TNC), CD34+ progenitor cells and colony forming units in UCB donations. Several studies have addressed the role of maternal/neonatal factors associated with the hematopoietic reconstruction potential of UCB, including: gestational age, maternal parity, newborn sex and birth weight, placental weight, labor duration and mode of delivery. Few data exist regarding as to how time influences UCB collection and banking patterns. We retrospectively analyzed 17.936 cord blood donations collected from 1999 to 2011 from Tuscany and Apulia Cord Blood Banks. Results from generalized multivariable linear mixed models showed that CBV, TNC and CD34+ cell were associated with known obstetric and neonatal parameters and showed rhythmic patterns in different time domains and frequency ranges. The present findings confirm that volume, total nucleated cells and stem cells of the UCB donations are hallmarked by rhythmic patterns in different time domains and frequency ranges and suggest that temporal rhythms in addition to known obstetric and neonatal parameters influence CBV, TNC and CD34+ cell content in UBC units.

  12. Polymorphisms of the coagulation factor Ⅶ gene and its plasma levels in relation to acute cerebral infarction differences in allelic frequencies between Chinese Han and European populations

    Institute of Scientific and Technical Information of China (English)

    康文英; 王鸿利; 熊立凡; 王学锋; 储海燕; 璩斌; 刘湘帆; 尹俊; 段宝华; 王振义

    2004-01-01

    Background Coagulation factor Ⅶ (F Ⅶ) levels in plasma are usually related to ischemic heart disease (IHD) and cerebral infarction shares many of the risk factors related to IHD. Is there any relationship between factor Ⅶ and cerebral infarction? We investigated the relationship between F Ⅶ and acute cerebral infarction and reported genotype frequencies and allelic frequencies of FⅦ gene polymorphisms in the Chinese Han population.Methods We recruited 62 patients with acute cerebral infarction confirmed by magnetic resonance imaging (MRI) from Ruijin Hospital, and 149 age-matched patients clinically free of vascular disease to act as controls. All of them were unrelated, and were from the Chinese Han population. FⅦ coagulant activity (FⅦc) was determined using an clotting assay, activated FⅦ (FⅦa) and FⅦ Ag were assayed using enzyme immunoassay kits. The FⅦ gene polymorphisms to be detected included-401G/T, -402G/A, 5'F7A1/A2, IVS7 and R353Q. 5'F7 and IVS7 were revealed by means of a PCR and direct agarose gel electrophoresis. The rest were examined by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results The results showed that FⅦc, FⅦAg and FⅦa were higher in the acute cerebral infarction group than in the control group (P<0.01, P<0.05, P<0.05, respectively). There were no significant differences in the genotype frequencies of FⅦ gene polymorphisms between the two groups. The allelic frequencies in the Chinese Han population were as follows: -401G/T (96.64/3.36), -402G/A (52.01/47.99), 5'F7A1/A2(96.64/3.36), IVS7 H5/H6/H7/H8 (0.34/52.35/46.98/0.34) and R353Q (95.64/4.36). There were significant differences (P<0.01, P<0.001, P<0.001, P<0.001, P<0.001, respectively) in these allelic frequencies between the Chinese Han and European populations.Conclusions The results indicate that increased plasma FⅦ levels may contribute to thrombosis in cerebral infarction. And there was no significant difference

  13. Hippocampal place cells construct reward related sequences through unexplored space.

    Science.gov (United States)

    Ólafsdóttir, H Freyja; Barry, Caswell; Saleem, Aman B; Hassabis, Demis; Spiers, Hugo J

    2015-06-26

    Dominant theories of hippocampal function propose that place cell representations are formed during an animal's first encounter with a novel environment and are subsequently replayed during off-line states to support consolidation and future behaviour. Here we report that viewing the delivery of food to an unvisited portion of an environment leads to off-line pre-activation of place cells sequences corresponding to that space. Such 'preplay' was not observed for an unrewarded but otherwise similar portion of the environment. These results suggest that a hippocampal representation of a visible, yet unexplored environment can be formed if the environment is of motivational relevance to the animal. We hypothesise such goal-biased preplay may support preparation for future experiences in novel environments.

  14. A pilot study showing associations between frequency of CD4(+) memory cell subsets at diagnosis and duration of partial remission in type 1 diabetes.

    Science.gov (United States)

    Moya, Rosita; Robertson, Hannah Kathryn; Payne, Dawson; Narsale, Aditi; Koziol, Jim; Davies, Joanna Davida

    2016-05-01

    In some patients with type 1 diabetes the dose of insulin required to achieve euglycemia is substantially reduced soon after diagnosis. This partial remission is associated with β-cell function and good glucose control. The purpose of this study was to assess whether frequencies of CD4(+) T cell subsets in children newly diagnosed with type 1 diabetes are associated with length of partial remission. We found that the frequency of CD4(+) memory cells, activated Treg cells and CD25(+) cells that express a high density of the IL-7 receptor, CD127 (CD127(hi)) are strongly associated with length of partial remission. Prediction of length of remission via Cox regression is significantly enhanced when CD25(+) CD127(hi) cell frequency is combined with either Insulin Dependent Adjusted A1c (IDAA1c), or glycosylated hemoglobin (HbA1c), or C-peptide levels at diagnosis. CD25(+) CD127(hi) cells do not express Foxp3, LAG-3 and CD49b, indicating that they are neither Treg nor Tr1 cells. PMID:27114212

  15. Cell Type Related Differences in Staining with Pentameric Thiophene Derivatives

    OpenAIRE

    Cieslar-Pobuda, Artur; Bäck, Marcus; Magnusson, Karin; Vilas Jain, Mayur; Rafat, Mehrdad; Ghavami, Saeid; Nilsson, Peter R.; Los, Marek Jan

    2014-01-01

    Fluorescent compounds capable of staining cells selectively without affecting their viability are gaining importance in biology and medicine. Recently, a new family of optical dyes, denoted luminescent conjugated oligothiophenes (LCOs), has emerged as an interesting class of highly emissive molecules for studying various biological phenomena. Properly functionalized LCOs have been utilized for selective identification of disease-associated protein aggregates and for selective detection of dis...

  16. Extremely low frequency electromagnetic field sensitizes cisplatin-resistant human ovarian adenocarcinoma cells via P53 activation.

    Science.gov (United States)

    Baharara, Javad; Hosseini, Nasrin; Farzin, Tayebe Ramezani

    2016-08-01

    In the following study, extremely low frequency electromagnetic fields (EL-EMF) radiation was used to restore sensitivity in the cisplatin-resistant A2780 ovarian cancer cells. For this purpose A2780 cells were treated with different doses of cisplatin and EL-EMF (50 Hz, 200 gauss, and 2 h) alone. Cytotoxicity was the measurement using MTT assay. After calculating IC50 for cisplatin (90 µg/ml) a lower concentration from IC50 (30 and 60 µg/ml) was used to be combined with EL-EMF. We compare the effects of each cisplatin, EL-EMF and combination groups using acridine orange-propidium iodide (AO/PI) and DAPI staining, caspase 3/9 activation assay and Annexin/PI assay. We also assessed changes in P53 and Matrix metalloproteinases 2 (MMPs) gene expression with semi-quantitative RT-PCR. Results indicated an EL-EMF-dependent proliferative decrease which was found <10 %, and occurred independently of cisplatin. The decreased proliferation rate for 30 and 60 µg/ml cisplatin was about 20 and 40 %, respectively, while for synergistic groups 30 and 60 µg/ml cisplatin with 2 h EL-EMF exposer, showed 47 and 71 % decrease in viability in rats. DAPI staining indicated that chromatin break down significantly increased in synergistic groups. Acridine orange staining also confirmed MTT assay results. Caspase activity significantly increased in the combined groups. Semi-quantitative RT-PCR showed that in synergistic groups of cisplatin and EL-EMF, expression of P53 was increased but the expression level of MPP-2 gene decreased. Results from this study showed that changes generated by the non-invasive EL-EMF can make resistant cells sensitive to cisplatin. PMID:26370097

  17. C-MYC and BCL2 translocation frequency in diffuse large B-cell lymphomas: A study of 97 patients

    Directory of Open Access Journals (Sweden)

    Bahar Akkaya

    2016-01-01

    Full Text Available Purpose: Diffuse large B-cell lymphoma (DLBCL is an aggressive non-Hodgkin lymphoma with marked biologic heterogeneity. MYC and BCL2 rearrangements have been reported in a proportion of DLBCLs, where they may be associated with an adverse clinical outcome. The aim of this study was to determine the frequency of MYC and BCL2 translocations in DLBCL and assess the prognostic impact in DLBCL patients. Materials and Methods:   In the present study, we evaluated the expression patterns of CD 10, BCL6, and MUM 1 by immunohistochemistry in 121 cases with DLBCL in tissue microarray (TMA: 62 cases in germinal center B-cells (GCBs; and 59 cases in activated B-cells (ABCs of which 60 were females and 61 were males. MYC and BCL2 rearrangements were investigated by interphase fluorescence in situ hybridization on TMAs in 97 DLBCLs. Result: MYC rearrangements were observed in 11 of 97 cases. There was no association with other clinical features, including age, sex, and nodal/extranodal disease. MYC rearrangement was associated with significantly worse overall survival (P < 0.01. BCL2 rearrangements were observed in 14 of 97 cases. There was no association with other clinical features including age and sex. BCL2 rearrangement had a worse outcome (P < 0.01. MYC and BCL2 rearrangements were observed in 3 of 97 cases with the age of  53 (female, 53, 63 years old, respectively, died in 24, 18, and 35 months after the diagnosis. Two cases had primary nodal and one case primary extranodal presentations. All these patients had stage IV disease. Conclusion: We concluded that C-MYC and BCL2 may contribute to aggressive transformation, and more mechanism-based therapy should be explored. Targeted therapies involving these rearrangements and its associated pathways may change the fate of DLBCLs. Analysis of MYC gene rearrangement along with BCL2 is critical in the identification of high-risk patients with poor prognosis.

  18. Causal determination of acoustic group velocity and frequency derivative of attenuation with finite-bandwidth Kramers-Kronig relations

    Science.gov (United States)

    Mobley, Joel; Waters, Kendall R.; Miller, James G.

    2005-07-01

    Kramers-Kronig (KK) analyses of experimental data are complicated by the extrapolation problem, that is, how the unexamined spectral bands impact KK calculations. This work demonstrates the causal linkages in resonant-type data provided by acoustic KK relations for the group velocity (cg) and the derivative of the attenuation coefficient (α') (components of the derivative of the acoustic complex wave number) without extrapolation or unmeasured parameters. These relations provide stricter tests of causal consistency relative to previously established KK relations for the phase velocity (cp) and attenuation coefficient (α) (components of the undifferentiated acoustic wave number) due to their shape invariance with respect to subtraction constants. For both the group velocity and attenuation derivative, three forms of the relations are derived. These relations are equivalent for bandwidths covering the entire infinite spectrum, but differ when restricted to bandlimited spectra. Using experimental data from suspensions of elastic spheres in saline, the accuracy of finite-bandwidth KK predictions for cg and α' is demonstrated. Of the multiple methods, the most accurate were found to be those whose integrals were expressed only in terms of the phase velocity and attenuation coefficient themselves, requiring no differentiated quantities.

  19. Causal determination of acoustic group velocity and frequency derivative of attenuation with finite-bandwidth Kramers-Kronig relations.

    Science.gov (United States)

    Mobley, Joel; Waters, Kendall R; Miller, James G

    2005-07-01

    Kramers-Kronig (KK) analyses of experimental data are complicated by the extrapolation problem, that is, how the unexamined spectral bands impact KK calculations. This work demonstrates the causal linkages in resonant-type data provided by acoustic KK relations for the group velocity (c(g)) and the derivative of the attenuation coefficient (alpha') (components of the derivative of the acoustic complex wave number) without extrapolation or unmeasured parameters. These relations provide stricter tests of causal consistency relative to previously established KK relations for the phase velocity (c(p)) and attenuation coefficient (alpha) (components of the undifferentiated acoustic wave number) due to their shape invariance with respect to subtraction constants. For both the group velocity and attenuation derivative, three forms of the relations are derived. These relations are equivalent for bandwidths covering the entire infinite spectrum, but differ when restricted to bandlimited spectra. Using experimental data from suspensions of elastic spheres in saline, the accuracy of finite-bandwidth KK predictions for c(g) and alpha' is demonstrated. Of the multiple methods, the most accurate were found to be those whose integrals were expressed only in terms of the phase velocity and attenuation coefficient themselves, requiring no differentiated quantities.

  20. TUMOR-RELATED METHYLATED CELL-FREE DNA AND CIRCULATING TUMOR CELLS IN MELANOMA

    Directory of Open Access Journals (Sweden)

    Francesca eSalvianti

    2016-01-01

    Full Text Available Solid tumor release into the circulation cell-free DNA (cfDNA and circulating tumor cells (CTCs which represent promising biomarkers for cancer diagnosis. Circulating tumor DNA may be studied in plasma from cancer patients by detecting tumor specific alterations, such as genetic or epigenetic modifications. Ras association domain family 1 isoform A (RASSF1A is a tumor suppressor gene silenced by promoter hypermethylation in a variety of human cancers including melanoma.The aim of the present study was to assess the diagnostic performance of a tumor-related methylated cfDNA marker in melanoma patients and to compare this parameter with the presence of CTCs.RASSF1A promoter methylation was quantified in cfDNA by qPCR in a consecutive series of 84 melanoma patients and 68 healthy controls. In a subset of 68 cases, the presence of CTCs was assessed by a filtration method (Isolation by Size of Epithelial Tumor Cells, ISET as well as by an indirect method based on the detection of tyrosinase mRNA by RT-qPCR. The distribution of RASSF1A methylated cfDNA was investigated in cases and controls and the predictive capability of this parameter was assessed by means of the area under the ROC curve (AUC.The percentage of cases with methylated RASSF1A promoter in cfDNA was significantly higher in each class of melanoma patients (in situ, invasive and metastatic than in healthy subjects (Pearson chi-squared test, p<0.001. The concentration of RASSF1A methylated cfDNA in the subjects with a detectable quantity of methylated alleles was significantly higher in melanoma patients than in controls. The biomarker showed a good predictive capability (in terms of AUC in discriminating between melanoma patients and healthy controls. This epigenetic marker associated to cfDNA did not show a significant correlation with the presence of CTCs, but, when the two parameters are jointly considered, we obtain a higher sensitivity of the detection of positive cases in invasive

  1. Tumor-Related Methylated Cell-Free DNA and Circulating Tumor Cells in Melanoma

    Science.gov (United States)

    Salvianti, Francesca; Orlando, Claudio; Massi, Daniela; De Giorgi, Vincenzo; Grazzini, Marta; Pazzagli, Mario; Pinzani, Pamela

    2016-01-01

    Solid tumor release into the circulation cell-free DNA (cfDNA) and circulating tumor cells (CTCs) which represent promising biomarkers for cancer diagnosis. Circulating tumor DNA may be studied in plasma from cancer patients by detecting tumor specific alterations, such as genetic or epigenetic modifications. Ras association domain family 1 isoform A (RASSF1A) is a tumor suppressor gene silenced by promoter hypermethylation in a variety of human cancers including melanoma. The aim of the present study was to assess the diagnostic performance of a tumor-related methylated cfDNA marker in melanoma patients and to compare this parameter with the presence of CTCs. RASSF1A promoter methylation was quantified in cfDNA by qPCR in a consecutive series of 84 melanoma patients and 68 healthy controls. In a subset of 68 cases, the presence of CTCs was assessed by a filtration method (Isolation by Size of Epithelial Tumor Cells, ISET) as well as by an indirect method based on the detection of tyrosinase mRNA by RT-qPCR. The distribution of RASSF1A methylated cfDNA was investigated in cases and controls and the predictive capability of this parameter was assessed by means of the area under the ROC curve (AUC). The percentage of cases with methylated RASSF1A promoter in cfDNA was significantly higher in each class of melanoma patients (in situ, invasive and metastatic) than in healthy subjects (Pearson chi-squared test, p < 0.001). The concentration of RASSF1A methylated cfDNA in the subjects with a detectable quantity of methylated alleles was significantly higher in melanoma patients than in controls. The biomarker showed a good predictive capability (in terms of AUC) in discriminating between melanoma patients and healthy controls. This epigenetic marker associated to cfDNA did not show a significant correlation with the presence of CTCs, but, when the two parameters are jointly considered, we obtain a higher sensitivity of the detection of positive cases in invasive and

  2. Frequency of anti-HCV, Hbsag and related risk factors in pregnant women at Nishtar Hospital, Multan

    International Nuclear Information System (INIS)

    Background: Viral hepatitis is a global issue. Among the hepatitis viruses hepatitis B and C are important in South Asia including Pakistan. There are various modes of transmission of these viruses. Vertical transmission is also gaining importance. Antepartum screening for HBV and HCV would help the infected women for appropriate antiviral therapy at appropriate time as well as for taking proper care of the newborns. The present study was designed to see the frequency of HBsAg and anti-HCV in pregnant women at Nishtar Hospital, Multan. Methods: This was a cross-sectional study carried out using non-probability purposive sampling technique. The period of the study was from June 2006 to August 2007. Five hundred (500) pregnant women attending outpatient department of Gynaecology and Obstetrics were included. Informed consent was taken. A specially designed proforma was filled in. Anti-HCV and HBsAg were tested by device method. Data were analyzed on SPSS-11. Results: Out of 500 pregnant women 35 (7.00%) were found to be anti-HCV positive and 23 (4.60%) were positive for HBsAg. Mean age was 26.7+-4.8 years. Majority of the patients 263 (52.60%) were in the age group 26-35 years. 138 (27.60%) women were nulliparous and 282 (56.40%) were para 1-4 and anti-HCV and HBsAg were common in this parity group. Only 80 (16.00%) women were para 5 or more. All anti-HCV and HBsAg positive women were house-wives. Most of them were belonging to rural areas having poor socio-economic status. Among 35 anti-HCV positive women, 20 (57.14%) had history of previous surgery, while 13 (37.14%) had history of multiple injections, 5 (14.28%) received blood transfusion, 4 (11.42%) had ear/nose piercing while tattooing was seen in only 2 (5.71%). Among 23 HBsAg positive women, 10 (43.47%) had history of previous surgery. History of multiple injections was present in 6 (26.08%) patients, 4 (17.39%) patients had history of blood transfusion, tattooing, ear/nose piercing, history of dental

  3. Brain dynamics in the comprehension of action-related language. A time-frequency analysis of mu rhythms.

    Science.gov (United States)

    Moreno, Iván; de Vega, Manuel; León, Inmaculada; Bastiaansen, Marcel; Glen Lewis, Ashley; Magyari, Lilla

    2015-04-01

    EEG mu rhythms (8-13 Hz) recorded at fronto-central electrodes are generally considered as markers of motor cortical activity in humans, because they are modulated when participants perform an action, when they observe another's action or even when they imagine performing an action. In this study, we analyzed the time-frequency (TF) modulation of mu rhythms while participants read action language ("You will cut the strawberry cake"), abstract language ("You will doubt the patient's argument"), and perceptive language ("You will notice the bright day"). The results indicated that mu suppression at fronto-central sites is associated with action language rather than with abstract or perceptive language. Also, the largest difference between conditions occurred quite late in the sentence, while reading the first noun, (contrast Action vs. Abstract), or the second noun following the action verb (contrast Action vs. Perceptive). This suggests that motor activation is associated with the integration of words across the sentence beyond the lexical processing of the action verb. Source reconstruction localized mu suppression associated with action sentences in premotor cortex (BA 6). The present study suggests (1) that the understanding of action language activates motor networks in the human brain, and (2) that this activation occurs online based on semantic integration across multiple words in the sentence.

  4. The National Parliamentary Arena and Methods of Open Coordination: Explaining the Frequency of OMC-related Executive-legislature Interactions

    Directory of Open Access Journals (Sweden)

    Rik de Ruiter

    2011-02-01

    Full Text Available This article tests the importance of different factors for the frequency with which information from open methods of coordination (OMCs is used in parliamentary debates. Previous research has shown that OMCs provide the executive and the legislature with information on best and worst national policy practices, enabling them to adopt different strategies. First, a national government can fame its own policies with the use of information from OMCs. Second, information from OMCs can be used by parliamentarians of opposition parties to shame the policies of the incumbent government. A study of Dutch parliamentary debates indicates that the Dutch government uses more information from OMCs to fame its own policies when OMCs have a developed infrastructure and/or a treaty base. Parliamentarians from opposition parties use more information from OMCs adopted for policy areas in which there was already EU-level activity prior to the OMC, and the government provided information on the substance of OMCs to members of national parliaments.

  5. RELATION BETWEEN SUMMER TYPHOON FREQUENCY ANOMALIES IN WEST PACIFIC AND ENSO EVENTS AND THE ANOMALOUS ATMOSPHERIC CIRCULATION CHARACTERISTICS

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xue-ming; WEI Ying-zhi; WU Chen-feng

    2006-01-01

    By using data of serially numbered typhoons in northwestern Pacific and NOAA OLR data and NCEP/NCAR reanalysis data of wind field, based on the statistics and study of the relationship between the calendar years with more (or fewer) summer typhoons and ENSO events, we compared the composites of OLR eigenvectors and tropical summer wind fields during El Ni(n)o and La Ni(n)o events with more or fewer than normal summer typhoons, respectively. The results show that, in summer, without remarkable systematic anomalies of Mascarene High and Australia High in South Hemisphere, the anomaly of Walker circulation will dominate and follow the rule of ENSO impacts to atmospheric circulation and typhoon frequency. Otherwise,when systematic anomalies of Australia High appear during the El Ni(n)o events, circulation anomalies in the South Hemisphere will dominate, and many more typhoons will occur. In 1999, which is a special year of La Ni(n)a events, northward and eastward monsoon was induced by the stronger Mascarene High, and fewer typhoons arose. The typhoon source are regions where weak vertical wind shear, warm pool in western Pacific and the area with monsoon troughs are overlapping with each other. Finally, this paper analyzes and compares the source locations and ranges of more (fewer) typhoons in the events of El Ni(n)o and La Ni(n)o, respectively.

  6. Both costs and benefits of sex correlate with relative frequency of asexual reproduction in cyclically parthenogenic Daphnia pulicaria populations.

    Science.gov (United States)

    Allen, Desiree E; Lynch, Michael

    2008-07-01

    Sexual reproduction is generally believed to yield beneficial effects via the expansion of expressed genetic variation, which increases the efficiency of selection and the adaptive potential of a population. However, when nonadditive gene action is involved, sex can actually impede the adaptive progress of a population. If selection promotes coupling disequilibria between genes of similar effect, recombination and segregation can result in a decrease in expressed genetic variance in the offspring population. In addition, when nonadditive gene action underlies a quantitative trait, sex can produce a change in trait means in a direction opposite to that favored by selection. In this study we measured the change in genotypic trait means and genetic variances across a sexual generation in four populations of the cyclical parthenogen Daphnia pulicaria, which vary predictably in their incidence of sexual reproduction. We show that both the costs and benefits of sex, as measured by changes in means and variances in life-history traits, increase substantially with decreasing frequency of sex.

  7. Relative validity of fruit and vegetable intake estimated by the food frequency questionnaire used in the Danish National Birth Cohort

    DEFF Research Database (Denmark)

    Mikkelsen, Tina B.; Olsen, Sjurdur F.; Rasmussen, Salka E.;

    2007-01-01

    Objective: To validate the fruit and vegetable intake estimated from the Food Frequency Questionnaire (FFQ) used in the Danish National Birth Cohort (DNBC). Subjects and setting: The DNBC is a cohort of 101,042 pregnant women in Denmark, who received a FFQ by mail in gestation week 25. A validation...... study with 88 participants was made. A seven-day weighed food diary (FD) and three different biomarkers were employed as comparison methods. Results: Significant correlations between FFQ and FD-based estimates were found for fruit (r=0.66); vegetables (r=0.32); juice (r=0.52); fruit and vegetables (F......&V) (r=0.57); and fruit, vegetables, and juice (F&V&J) (r=0.62). Sensitivities of correct classification by FFQ into the two lowest and the two highest quintiles of F&V&J intake were 58-67% and 50-74%, respectively, and specificities were 71-79% and 65-83%, respectively. F&V&J intake estimated from...

  8. Absolute and relative emission spectroscopy study of 3 cm wide planar radio frequency atmospheric pressure bio-plasma source

    Science.gov (United States)

    Deng, Xiaolong; Nikiforov, Anton Yu; Ionita, Eusebiu-Rosini; Dinescu, Gheorghe; Leys, Christophe

    2015-08-01

    The dynamics of low power atmospheric pressure radio frequency discharge generated in Ar gas in long gap of 3 cm is investigated. This plasma source is characterized and analyzed for possible large scale biomedical applications where low gas temperature and potential-less effluent are required. The discharge forms a homogenous glow-like afterglow in ambient air at input power of 30 W with low gas temperature of 330 K, which is desirable in biomedical applications. With absolute calibrated spectroscopy of the discharge, electron density of 0.4 × 1018 m-3 and electron temperature of 1.5 eV are obtained from continuum Bremsstrahlung radiation of the source. Time and spatial resolved emission spectroscopy is used to analyze discharge generation mechanism and active species formation. It is found that discharge dynamics strongly correlates with the discharge current waveform. Strong Ar(2p) excited states emission is observed nearby the electrodes surface on a distance up to 200 μm in the plasma sheath region at 10 ns after the current peak, whereas OH(A) emission is uniform along of the interelectrode gap.

  9. Polymorphism attribution of cSNPs in cancer-related genes located in loss regions with a high frequency of HCC between HBV and health groups

    Institute of Scientific and Technical Information of China (English)

    WANG Juan; NI Hong; CHEN Li; CHEN Chengbin; SONG Wenqin

    2007-01-01

    Cancer-related genes harbored in the loss regions containing a high frequency of hepatocellular carcinoma (HCC) were selected.Related information was gathered and the coding single nucleotide polymorphism (cSNP) sequences were obtained from the single nucleotide polymorphism (SNP) database.The appropriate primers and oligonucleotide probes were then designed in accordance with the SNP sites,and subsequently,the gene chips for detecting SNPs were constructed.Genomic DNA was extracted from blood samples of healthy controls and from patients with HBV infection.The sequences,including the SNPs,were amplified via polymerase chain reaction (PCR) and labeled using digoxigenin deoxyuridine tri-phosphate (Dig-dUTP).The labeled products were then hybridized with the SNP chips.Results confirmed that the differences in allele frequencies of three SNPs EGFL3 (rs947345),Caspase9 (rs2308950),and E2F2 (rs3218171) were distinct between HBV-infected patients and controls,suggesting that these SNPs ocuring in high frequency in HBV-infected individuals may be associated with susceptibility to HCC.

  10. [Quality of life and perceived general health state related to seizure type and frequency, electroencephalographic findings, cognitive impairment, therapeutic response and secondary effects in persons with epilepsy].

    Science.gov (United States)

    Rossinol, Antoni; Molina, Irene; Rossinol, Tomeu; Garcia-Mas, Alexandre

    2013-07-01

    INTRODUCTION. The perceived quality of life (QoL) in persons with epilepsy has demonstrated to be a relevant factor for the continuity of treatment and for the patients' own general health perception. Currently, the positive concept of QoL is used to assess the psychosocial factors of the epilepsy, replacing the concept of stigma. AIM. To analyze the relationship between QoL and general health perception, with several relevant clinical parameters in a sample of persons with epilepsy, in order to draw conclusions that help to suggest a more global approach to the disease. PATIENTS AND METHODS. We applied the Spanish versions of the QOLIE-10, the GHQ-12, and MMSE, and registered the clinical parameters (diagnostic, years of illness, electroencephalographic patterns, seizure type and frequency, response to medication, and side effects) in a sample of 29 persons with epilepsy. RESULTS. QoL and perceived general health are two unrelated factors respect to the clinical features. QoL is closely related to the frequency and type of crisis, whilst the years of illness and the level of neurocognitive impairment are not related with QoL. CONCLUSIONS. From the clinical point of view, it must be taken into account the relationship between the persons with epilepsy perceived QoL with factors such as the seizure frequency, side effects of the medication, and the general health perception, in order to obtain the best response and treatment adherence.

  11. An association, in adult Japanese, between the occurrence of rogue cells among cultured lymphocytes (JC virus activity) and the frequency of "simple" chromosomal damage among the lymphocytes of persons exhibiting these rogue cells.

    OpenAIRE

    Neel, J V

    1998-01-01

    Data from a previous study of the cytogenetic effects, in cultured lymphocytes, of exposure to the atomic bomb in Hiroshima have been reanalyzed to determine the relationship between the occurrence of "rogue" cells in an individual and the frequency of "simple" chromosomal damage in the nonrogue cells of the same individual. Rogue cells are cells with complex chromosomal damage, currently believed to be a manifestation of the activity of a human polyoma virus termed "JC." Among a total of 1,8...

  12. Relation between parthenolideinduced cytotoxicity and COX—2 expression in nasopharyngeal carcinoma cell

    Institute of Scientific and Technical Information of China (English)

    LinYL; OngCN

    2002-01-01

    To investigate the potential anti-tumor effects and its relative its relative mechanism of active component in chrysanthemum,on human nasopharyngeal carcinoma(NPC).Parthenolide(PN) was used as tested substance and exposed to NPC cell lines,CNE1 and CNE2.Cell toxicity indexes and cyclooxygenase-2(COX-2) expression were determined.Results showed that in CNE1 cells,with high level COX-2,there were significant cytotoxicities after PN-treated.However,there were not inducible effects on CNE2 cells with low level COX-2.It was indicated that PN could induce cytotoxicity in NPC cell,which correlated with its intracellular COX-2 expression.

  13. Theoretical Investigation on the Substituent Effect of Halogen Atoms at the C8 Position of Adenine: Relative Stability, Vibrational Frequencies, and Raman Spectra of Tautomers.

    Science.gov (United States)

    Chen, Yan-Li; Wu, De-Yin; Tian, Zhong-Qun

    2016-06-16

    We have theoretically investigated the substituent effect of adenine at the C8 position with a substituent X = H, F, Cl, and Br by using the density functional theory (DFT) at the B3LYP/6-311+G(d, p) level. The aim is to study the substituent effect of halogen atoms on the relative stability, vibrational frequencies, and solvation effect of tautomers. Our calculated results show that for substituted adenine molecules the N9H8X tautomer to be the most stable structure in gas phase at the present theoretical level. Here N9H8X denotes the hydrogen atom binds to the N9 position of imidazole ring and X denotes H, F, Cl, and Br atoms. The influence of the induced attraction of the fluorine substituent is significantly larger than chlorine and bromine ones. The halogen substituent effect has a significant influence on changes of vibrational frequencies and Raman intensities.

  14. Frequencies of 23 functionally significant variant alleles related with metabolism of antineoplastic drugs in the Chilean population: comparison with Caucasian and Asian populations

    Directory of Open Access Journals (Sweden)

    Angela Margarita Roco

    2012-11-01

    Full Text Available Cancer is a leading cause of death worldwide. The cancer incidence rate in Chile is 133.7/100,000 inhabitants and it is the second cause of death, after cardiovascular diseases. Most of the antineoplastic drugs are metabolized to be detoxified, and some of them to be activated. Genetic polymorphisms of drug-metabolizing enzymes can induce deep changes in enzyme activity, leading to individual variability in drug efficacy and/or toxicity. The present research describes the presence of genetic polymorphisms in the Chilean population, which might be useful in public health programs for personalized treatment of cancer, and compare these frequencies with those reported for Asian and Caucasian populations, as a contribution to the evaluation of ethnic differences in the response to chemotherapy.We analyzed 23 polymorphisms in a group of 253 unrelated Chilean volunteers from the general population. The results showed that CYP2A6*2, CYP2A6*3, CYP2D6*3, CYP2C19*3 and CYP3A4*17 variant alleles are virtually absent in Chileans. CYP1A1*2A allele frequency (0.37 is similar to that of Caucasians and higher than that reported for Japanese people. Allele frequencies for CYP3A5*3 (0.76 and CYP2C9*3 (0.04 are similar to those observed in Japanese people. CYP1A1*2C (0.32, CYP1A2*1F (0.77, CYP3A4*1B(0.06, CYP2D6*2(0.41 and MTHFR T(0.52 allele frequencies are higher than the observed either in Caucasian or in Japanese populations. Conversely, CYP2C19*2 allele frequency (0.12 and GSTT1null (0.11 and GSTM1null (0.36 genotype frequencies are lower than those observed in both populations. Finally, allele frequencies for CYP2A6*4(0.04, CYP2C8*3(0.06, CYP2C9*2(0.06, CYP2D6*4(0.12, CYP2E1*5B(0.14, CYP2E1*6(0.19, and UGT2B7*2(0.40 are intermediate in relation to those described in Caucasian and in Japanese populations, as expected according to the ethnic origin of the Chilean population.In conclusion, our findings support the idea that ethnic variability must be considered

  15. Micronucleus frequency in peripheral blood lymphocytes and buccal mucosa cells of copper smelter workers, with special regard to arsenic exposure.

    Science.gov (United States)

    Lewińska, D; Palus, J; Stepnik, M; Dziubałtowska, E; Beck, J; Rydzyński, K; Natarajan, A T; Nilsson, R

    2007-04-01

    Occupational exposure in copper smelters may produce various adverse health effects including cancer which, according to available epidemiologic data, is associated mainly with exposure to arsenic. Despite a number of well-documented studies reporting an increased risk of cancer among copper smelters workers, the data on genotoxic effects in this industry are scarce. In view of the above, an assessment of micronuclei (MN) frequency in peripheral blood lymphocytes and buccal epithelial cells from copper smelter workers was undertaken. Additionally, the clastogenic/aneugenic effect in lymphocytes was assessed with the fluorescence in situ hybridization (FISH). The study was conducted in three copper smelters in southwestern Poland. The subjects (n = 72) were enrolled among male workers at departments where As concentration in the air was up to at 80 microg/m(3). Exposure was assessed by measurement of arsenic concentration in urine and toenail samples. The control group (n = 83) was recruited from healthy male individuals living in central Poland who did not report any exposure to known genotoxins. The results of our study showed a significant increase in MN frequency in peripheral blood lymphocytes and in buccal epithelial cells of smelter workers, compared to the controls (7.96 +/- 4.28 vs. 3.47 +/- 1.70 and 0.98 +/- 0.76 vs. 0.50 +/- 0.52, respectively). The FISH technique revealed the presence of clastogenic and aneugenic effects in peripheral blood lymphocytes in both groups. The clastogenic effect was slightly more pronounced in the smelter workers; however, the difference was not statistically significant. The mean arsenic concentrations in urine (total arsenic species) and in toenail samples in the exposed group were 54.04 +/- 42.26 microg/l and 7.63 +/- 7.24 microg/g, respectively, being significantly different from control group 11.01 +/- 10.84 microg/l and 0.51 +/- 0.05 microg/g. No correlation between As content in urine or toenail samples and the

  16. Circulating brain derived neurotrophic factor (BDNF) and frequency of BDNF positive T cells in peripheral blood in human ischemic stroke: Effect on outcome.

    Science.gov (United States)

    Chan, Adeline; Yan, Jun; Csurhes, Peter; Greer, Judith; McCombe, Pamela

    2015-09-15

    The aim of this study was to measure the levels of circulating BDNF and the frequency of BDNF-producing T cells after acute ischaemic stroke. Serum BDNF levels were measured by ELISA. Flow cytometry was used to enumerate peripheral blood leukocytes that were labelled with antibodies against markers of T cells, T regulatory cells (Tregs), and intracellular BDNF. There was a slight increase in serum BDNF levels after stroke. There was no overall difference between stroke patients and controls in the frequency of CD4(+) and CD8(+) BDNF(+) cells, although a subgroup of stroke patients showed high frequencies of these cells. However, there was an increase in the percentage of BDNF(+) Treg cells in the CD4(+) population in stroke patients compared to controls. Patients with high percentages of CD4(+) BDNF(+) Treg cells had a better outcome at 6months than those with lower levels. These groups did not differ in age, gender or initial stroke severity. Enhancement of BDNF production after stroke could be a useful means of improving neuroprotection and recovery after stroke.

  17. Health-related Internet use by patients with somatic diseases: Frequency of use and characteristics of users

    NARCIS (Netherlands)

    Uden-Kraan, van Cornelia F.; Drossaert, Constance H.C.; Taal, Erik; Smit, Wim M.; Bernelot Moens, Hein J.; Siesling, Sabine; Seydel, Erwin R.; Laar, van de Mart A.F.J.

    2009-01-01

    The aim of this study was to explore the percentage of Dutch patients using the Internet to search for information about their illness. In addition, we studied patients' usage of health-related Internet applications, such as online patient support groups. The final objective of this study was to exp

  18. Early priming minimizes the age-related immune compromise of CD8⁺ T cell diversity and function.

    Directory of Open Access Journals (Sweden)

    Sophie A Valkenburg

    2012-02-01

    Full Text Available The elderly are particularly susceptible to influenza A virus infections, with increased occurrence, disease severity and reduced vaccine efficacy attributed to declining immunity. Experimentally, the age-dependent decline in influenza-specific CD8(+ T cell responsiveness reflects both functional compromise and the emergence of 'repertoire holes' arising from the loss of low frequency clonotypes. In this study, we asked whether early priming limits the time-related attrition of immune competence. Though primary responses in aged mice were compromised, animals vaccinated at 6 weeks then challenged >20 months later had T-cell responses that were normal in magnitude. Both functional quality and the persistence of 'preferred' TCR clonotypes that expand in a characteristic immunodominance hierarchy were maintained following early priming. Similar to the early priming, vaccination at 22 months followed by challenge retained a response magnitude equivalent to young mice. However, late priming resulted in reduced TCRβ diversity in comparison with vaccination earlier in life. Thus, early priming was critical to maintaining individual and population-wide TCRβ diversity. In summary, early exposure leads to the long-term maintenance of memory T cells and thus preserves optimal, influenza-specific CD8(+ T-cell responsiveness and protects against the age-related attrition of naïve T-cell precursors. Our study supports development of vaccines that prime CD8(+ T-cells early in life to elicit the broadest possible spectrum of CD8(+ T-cell memory and preserve the magnitude, functionality and TCR usage of responding populations. In addition, our study provides the most comprehensive analysis of the aged (primary, secondary primed-early and secondary primed-late TCR repertoires published to date.

  19. Frequency and Magnitude Analysis of the Macro-instability Related Component of the Tangential Force Affecting Radial Baffles in a Stirred Vessel

    Directory of Open Access Journals (Sweden)

    P. Hasal

    2002-01-01

    Full Text Available Experimental data obtained by measuring the tangential component of force affecting radial baffles in a flat-bottomed cylindrical mixing vessel stirred with pitched blade impellers is analysed. The maximum mean tangential force is detected at the vessel bottom. The mean force value increases somewhat with decreasing impeller off-bottom clearance and is noticeably affected by the number of impeller blades. Spectral analysis of the experimental data clearly demonstrated the presence of its macro-instability (MI related low-frequency component embedded in the total force at all values of impeller Reynolds number. The dimensionless frequency of the occurrence of the MI force component is independent of stirring speed, position along the baffle, number of impeller blades and liquid viscosity. Its mean value is about 0.074. The relative magnitude (QMI of the MI-related component of the total force is evaluated by a combination of proper orthogonal decomposition (POD and spectral analysis. Relative magnitude QMI was analysed in dependence on the frequency of the impeller revolution, the axial position of the measuring point in the vessel, the number of impeller blades, the impeller off-bottom clearance, and liquid viscosity. Higher values of QMI are observed at higher impeller off-bottom clearance height and (generally QMI decreases slightly with increasing impeller speed. The QMI value decreases in the direction from vessel bottom to liquid level. No evident difference was observed between 4 blade and 6 blade impellers. Liquid viscosity has only a marginal impact on the QMI value.

  20. [KI-1-positive, anaplastic, large-cell lymphoma related to Hodgkin's disease].

    Science.gov (United States)

    Veiga, M; Fresno, M F; Pérez del Río, M J; García, I; Madrigal, B; Herrero, A

    1997-02-01

    We report a case of lymphoma associated with lung carcinoma that shows morphological and immunohistochemical features of anaplastic large cell Ki-1 positive lymphoma and Hodgkin's disease, with positivity for Ki-1 (CD-30) (characteristic of both lymphomas) and Leu-M1 (CD-15) (normally dosent absent in anaplastic lymphoma). This subtype of lymphoma is designated anaplastic large-cell Hodgkin's related lymphoma (ALCL related to HD) and is considered by some authors as a secondary anaplastic large-cell lymphoma.