WorldWideScience

Sample records for brain-specific neural zinc

  1. The brain-specific neural zinc finger transcription factor 2b (NZF-2b/7ZFMyt1 suppresses cocaine self-administration in rats

    Directory of Open Access Journals (Sweden)

    Vijay Chandrasekar

    2010-04-01

    Full Text Available Brain-specific neural-zinc-finger transcription factor-2b (NZF2b/7ZFMyt1 is induced in the mesolimbic dopaminergic region after chronic cocaine exposure and lentiviral-mediated expression of NZF2b/7ZFMyt1 in the nucleus accumbens results in decreased locomotor activity (Chandrasekar and Dreyer, 2009. In this study the role of NZF2b/7ZFMyt1 in active cocaine seeking and of its interaction with histone deacetylase on the altered behavior has been observed. Localized expression of NZF2b/7ZFMyt1 in the nucleus accumbens resulted in attenuated cocaine self-administration, whereas silencing this transcription factor with lentiviruses expressing siRNAs increased the animal′s motivation to self-infuse cocaine. Low doses of sodium butyrate, a potent inhibitor of histone deacetylase, were sufficient to reverse the NZF2b/7ZFMyt1-mediated decrease in cocaine self-administration. NZF2b/7ZFMyt1 expression resulted in strong induction of transcription factors REST1 and NAC1 and of the dopamine D2 receptor, with concomitant inhibition of BDNF and its receptor TrkB. We show that NZF2b/7ZFMyt1 colocalizes with histone deacetylase-2 (HDAC2, probably overcoming the suppression of transcriptional activity caused by Lingo1. These findings show that molecular adaptations mediated by NZF2b/7ZFMyt1 expression possibly lead to decreased responsiveness to the reinforcing properties of cocaine and play a prominent role in affecting the behavioral changes induced by the drug.

  2. Serum zinc levels in newborns with neural tube defects.

    Science.gov (United States)

    Golalipour, Mohammad Jafar; Mansourian, Azad Reza; Keshtkar, Abasali

    2006-09-01

    Neural tube defects (NTD) comprise of a group of congenital malformations that include spina bifida, anencephaly and encephalocele. Reports have implicated zinc deficiency as one of the causative factors of NTDs. We compared the serum zinc level of 23 newborns having neural tube defects with 35 healthy controls by spectrophotometery during 2003-2004. Zinc deficiency was documented in 43.5% of the cases and 8.6% of the controls (P = 0.002). Multivariate logistic regression analysis revealed a significant association between the presence of NTDs and zinc deficiency (OR = 8.2, 95% Cl: 1.9-34.7).

  3. Forecasting of Zinc Coating Thickness with Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Tuğçen Hatipoğlu

    2013-01-01

    Full Text Available Since the competition level among the companies is increasing day by day, meeting customer demands with qualified products and cost reduction are primary goals of each company. And zinc, the main raw material in galvanization sector, is the most important cost item. So it is required to forecast the amount of zinc to be spent. In this study it is tried to forecast the amount of zinc consumption using the artificial neural network (ANN method. To evaluate the convenience of values hypothesis tests are done; and the results showed that there is no significant difference between the predicted and real outputs statistically.

  4. Implications of Zinc on Fetal Neural Tube Defects

    Directory of Open Access Journals (Sweden)

    Rajeev Vats

    2012-07-01

    Full Text Available Zinc is essential for normal growth and differentiation in all mammalian species and it is reported that folic acid supplementation has reduced the incidence of neural tube defects (NTD. It is still considered one of the important congenital malformations having wide implications. Zinc deficiency has been reported to produce NTD in animals. The present study was undertaken to evaluate zinc status of newborn babies with NTD and their mothers. Blood samples were taken from 287 mothers and their babies having NTD and from 110 controls visiting hospitals and health clinics. Zinc level as µg/ml for blood and serum and µg/g for cell mass were determined on GBC 932 atomic absorption spectrophotometer (Australia by fluorometery. The mean maternal blood, serum and cell mass concentration in NTD group (14.56 ± 1.34 µg/ml, 0.6 ± 0.01 µg/ml, 5.64 ± 0.35 µg/gm respectively were significantly lower than those of the control mothers (24.15 ± 2.95 µg/ml, 0.72 ± 0.03 µg/ml, 7.37 ± 0.44 µg/gm respectively. There is a significant decrease in the concentration of Zinc in newborns having NTD (15.65 ± 3.18 µg/ml, 0.56 ± 0.08 µg/ml, 5.11 ± 0.18 µg/gm respectively as compared with normal newborns (28.04 ± 1.1 µg/ml, 0.59 ± 0.08 µg/ml and 6.08 ± 0.29 µg/gm respectively. Maternal nutritional zinc deficiency in newborns and their mothers is thought to be one of the factors responsible for NTD. However, the lowered zinc concentration may be influencing the causation of NTD. More investigations on zinc status in mothers during antenatal period, especially in the prenatal development and antenatal zinc status including normal babies and NTD babies are required at population level.

  5. Zinc in the Monoaminergic Theory of Depression: Its Relationship to Neural Plasticity

    Directory of Open Access Journals (Sweden)

    Urszula Doboszewska

    2017-01-01

    Full Text Available Preclinical and clinical studies have demonstrated that zinc possesses antidepressant properties and that it may augment the therapy with conventional, that is, monoamine-based, antidepressants. In this review we aim to discuss the role of zinc in the pathophysiology and treatment of depression with regard to the monoamine hypothesis of the disease. Particular attention will be paid to the recently described zinc-sensing GPR39 receptor as well as aspects of zinc deficiency. Furthermore, an attempt will be made to give a possible explanation of the mechanisms by which zinc interacts with the monoamine system in the context of depression and neural plasticity.

  6. Zinc

    Science.gov (United States)

    ... increase zinc absorption, although a protein in cow's milk slows absorption down. Soy proteins also reduce zinc absorption, possibly due to their ... cow's milk, and even less from soy-based milk. It isn't known whether high-protein diets influence zinc balance in adults.VegetarianismVegetarian diets ...

  7. Embryonic neural inducing factor churchill is not a DNA-binding zinc finger protein: solution structure reveals a solvent-exposed beta-sheet and zinc binuclear cluster.

    Science.gov (United States)

    Lee, Brian M; Buck-Koehntop, Bethany A; Martinez-Yamout, Maria A; Dyson, H Jane; Wright, Peter E

    2007-08-31

    Churchill is a zinc-containing protein that is involved in neural induction during embryogenesis. At the time of its discovery, it was thought on the basis of sequence alignment to contain two zinc fingers of the C4 type. Further, binding of an N-terminal GST-Churchill fusion protein to a particular DNA sequence was demonstrated by immunoprecipitation selection assay, suggesting that Churchill may function as a transcriptional regulator by sequence-specific DNA binding. We show by NMR solution structure determination that, far from containing canonical C4 zinc fingers, the protein contains three bound zinc ions in novel coordination sites, including an unusual binuclear zinc cluster. The secondary structure of Churchill is also unusual, consisting of a highly solvent-exposed single-layer beta-sheet. Hydrogen-deuterium exchange and backbone relaxation measurements reveal that Churchill is unusually dynamic on a number of time scales, with the exception of regions surrounding the zinc coordinating sites, which serve to stabilize the otherwise unstructured N terminus and the single-layer beta-sheet. No binding of Churchill to the previously identified DNA sequence could be detected, and extensive searches using DNA sequence selection techniques could find no other DNA sequence that was bound by Churchill. Since the N-terminal amino acids of Churchill form part of the zinc-binding motif, the addition of a fusion protein at the N terminus causes loss of zinc and unfolding of Churchill. This observation most likely explains the published DNA-binding results, which would arise due to non-specific interaction of the unfolded protein in the immunoprecipitation selection assay. Since Churchill does not appear to bind DNA, we suggest that it may function in embryogenesis as a protein-interaction factor.

  8. [Zinc].

    Science.gov (United States)

    Couinaud, C

    1984-10-01

    Zinc is indispensable for life from bacteria to man. As a trace element it is included in numerous enzymes or serves as their activator (more than 80 zinc metallo-enzymes). It is necessary for nucleic acid and protein synthesis, the formation of sulphated molecules (insulin, growth hormone, keratin, immunoglobulins), and the functioning of carbonic anhydrase, aldolases, many dehydrogenases (including alcohol-dehydrogenase, retinal reductase indispensable for retinal rod function), alkaline phosphatase, T cells and superoxide dismutase. Its lack provokes distinctive signs: anorexia, diarrhea, taste, smell and vision disorders, skin lesions, delayed healing, growth retardation, delayed appearance of sexual characteristics, diminished resistance to infection, and it may be the cause of congenital malformations. Assay is now simplified by atomic absorption spectrophotometry in blood or hair. There is a latent lack prior to any disease because of the vices of modern eating habits, and this increases during stress, infections or tissue healing processes. Its lack is accentuated during long-term parenteral feeding or chronic gastrointestinal affections. Correction is as simple as it is innocuous, and zinc supplements should be given more routinely during surgical procedures.

  9. The Brain-Specific Beta4 Subunit Downregulates BK Channel Cell Surface Expression

    OpenAIRE

    Sonal Shruti; Joanna Urban-Ciecko; Fitzpatrick, James A.; Robert Brenner; Bruchez, Marcel P.; Alison L Barth

    2012-01-01

    The large-conductance K(+) channel (BK channel) can control neural excitability, and enhanced channel currents facilitate high firing rates in cortical neurons. The brain-specific auxiliary subunit β4 alters channel Ca(++)- and voltage-sensitivity, and β4 knock-out animals exhibit spontaneous seizures. Here we investigate β4's effect on BK channel trafficking to the plasma membrane. Using a novel genetic tag to track the cellular location of the pore-forming BKα subunit in living cells, we fi...

  10. Conversion of Human Fibroblasts to Stably Self-Renewing Neural Stem Cells with a Single Zinc-Finger Transcription Factor

    Directory of Open Access Journals (Sweden)

    Ebrahim Shahbazi

    2016-04-01

    Full Text Available Direct conversion of somatic cells into neural stem cells (NSCs by defined factors holds great promise for mechanistic studies, drug screening, and potential cell therapies for different neurodegenerative diseases. Here, we report that a single zinc-finger transcription factor, Zfp521, is sufficient for direct conversion of human fibroblasts into long-term self-renewable and multipotent NSCs. In vitro, Zfp521-induced NSCs maintained their characteristics in the absence of exogenous factor expression and exhibited morphological, molecular, developmental, and functional properties that were similar to control NSCs. In addition, the single-seeded induced NSCs were able to form NSC colonies with efficiency comparable with control NSCs and expressed NSC markers. The converted cells were capable of surviving, migrating, and attaining neural phenotypes after transplantation into neonatal mouse and adult rat brains, without forming tumors. Moreover, the Zfp521-induced NSCs predominantly expressed rostral genes. Our results suggest a facilitated approach for establishing human NSCs through Zfp521-driven conversion of fibroblasts.

  11. The brain-specific Beta4 subunit downregulates BK channel cell surface expression.

    Science.gov (United States)

    Shruti, Sonal; Urban-Ciecko, Joanna; Fitzpatrick, James A; Brenner, Robert; Bruchez, Marcel P; Barth, Alison L

    2012-01-01

    The large-conductance K(+) channel (BK channel) can control neural excitability, and enhanced channel currents facilitate high firing rates in cortical neurons. The brain-specific auxiliary subunit β4 alters channel Ca(++)- and voltage-sensitivity, and β4 knock-out animals exhibit spontaneous seizures. Here we investigate β4's effect on BK channel trafficking to the plasma membrane. Using a novel genetic tag to track the cellular location of the pore-forming BKα subunit in living cells, we find that β4 expression profoundly reduces surface localization of BK channels via a C-terminal ER retention sequence. In hippocampal CA3 neurons from C57BL/6 mice with endogenously high β4 expression, whole-cell BK channel currents display none of the characteristic properties of BKα+β4 channels observed in heterologous cells. Finally, β4 knock-out animals exhibit a 2.5-fold increase in whole-cell BK channel current, indicating that β4 also regulates current magnitude in vivo. Thus, we propose that a major function of the brain-specific β4 subunit in CA3 neurons is control of surface trafficking.

  12. The brain-specific Beta4 subunit downregulates BK channel cell surface expression.

    Directory of Open Access Journals (Sweden)

    Sonal Shruti

    Full Text Available The large-conductance K(+ channel (BK channel can control neural excitability, and enhanced channel currents facilitate high firing rates in cortical neurons. The brain-specific auxiliary subunit β4 alters channel Ca(++- and voltage-sensitivity, and β4 knock-out animals exhibit spontaneous seizures. Here we investigate β4's effect on BK channel trafficking to the plasma membrane. Using a novel genetic tag to track the cellular location of the pore-forming BKα subunit in living cells, we find that β4 expression profoundly reduces surface localization of BK channels via a C-terminal ER retention sequence. In hippocampal CA3 neurons from C57BL/6 mice with endogenously high β4 expression, whole-cell BK channel currents display none of the characteristic properties of BKα+β4 channels observed in heterologous cells. Finally, β4 knock-out animals exhibit a 2.5-fold increase in whole-cell BK channel current, indicating that β4 also regulates current magnitude in vivo. Thus, we propose that a major function of the brain-specific β4 subunit in CA3 neurons is control of surface trafficking.

  13. Synthesis of zinc oxide nanoparticles-chitosan for extraction of methyl orange from water samples: Cuckoo optimization algorithm-artificial neural network

    Science.gov (United States)

    Khajeh, Mostafa; Golzary, Ali Reza

    2014-10-01

    In this work, zinc nanoparticles-chitosan based solid phase extraction has been developed for separation and preconcentration of trace amount of methyl orange from water samples. Artificial neural network-cuckoo optimization algorithm has been employed to develop the model for simulation and optimization of this method. The pH, volume of elution solvent, mass of zinc oxide nanoparticles-chitosan, flow rate of sample and elution solvent were the input variables, while recovery of methyl orange was the output. The optimum conditions were obtained by cuckoo optimization algorithm. At the optimum conditions, the limit of detections of 0.7 μg L-1was obtained for the methyl orange. The developed procedure was then applied to the separation and preconcentration of methyl orange from water samples.

  14. Synthesis of zinc oxide nanoparticles-chitosan for extraction of methyl orange from water samples: cuckoo optimization algorithm-artificial neural network.

    Science.gov (United States)

    Khajeh, Mostafa; Golzary, Ali Reza

    2014-10-15

    In this work, zinc nanoparticles-chitosan based solid phase extraction has been developed for separation and preconcentration of trace amount of methyl orange from water samples. Artificial neural network-cuckoo optimization algorithm has been employed to develop the model for simulation and optimization of this method. The pH, volume of elution solvent, mass of zinc oxide nanoparticles-chitosan, flow rate of sample and elution solvent were the input variables, while recovery of methyl orange was the output. The optimum conditions were obtained by cuckoo optimization algorithm. At the optimum conditions, the limit of detections of 0.7μgL(-1)was obtained for the methyl orange. The developed procedure was then applied to the separation and preconcentration of methyl orange from water samples.

  15. Biotreatment of zinc-containing wastewater in a sulfidogenic CSTR: Performance and artificial neural network (ANN) modelling studies

    Energy Technology Data Exchange (ETDEWEB)

    Sahinkaya, Erkan [Harran University, Environmental Engineering Department, Osmanbey Campus, 63000 Sanliurfa (Turkey)], E-mail: erkansahinkaya@yahoo.com

    2009-05-15

    Sulfidogenic treatment of sulfate (2-10 g/L) and zinc (65-677 mg/L) containing simulated wastewater was studied in a mesophilic (35 deg. C) CSTR. Ethanol was supplemented (COD/sulfate = 0.67) as carbon and energy source for sulfate-reducing bacteria (SRB). The robustness of the system was studied by increasing Zn, COD and sulfate loadings. Sulfate removal efficiency, which was 70% at 2 g/L feed sulfate concentration, steadily decreased with increasing feed sulfate concentration and reached 40% at 10 g/L. Over 99% Zn removal was attained due to the formation of zinc-sulfide precipitate. COD removal efficiency at 2 g/L feed sulfate concentration was over 94%, whereas, it steadily decreased due to the accumulation of acetate at higher loadings. Alkalinity produced from acetate oxidation increased wastewater pH remarkably when feed sulfate concentration was 5 g/L or lower. Electron flow from carbon oxidation to sulfate reduction averaged 83 {+-} 13%. The rest of the electrons were most likely coupled with fermentative reactions as the amount of methane production was insignificant. The developed ANN model was very successful as an excellent to reasonable match was obtained between the measured and the predicted concentrations of sulfate (R = 0.998), COD (R = 0.993), acetate (R = 0.976) and zinc (R = 0.827) in the CSTR effluent.

  16. Biotreatment of zinc-containing wastewater in a sulfidogenic CSTR: Performance and artificial neural network (ANN) modelling studies.

    Science.gov (United States)

    Sahinkaya, Erkan

    2009-05-15

    Sulfidogenic treatment of sulfate (2-10g/L) and zinc (65-677mg/L) containing simulated wastewater was studied in a mesophilic (35 degrees C) CSTR. Ethanol was supplemented (COD/sulfate=0.67) as carbon and energy source for sulfate-reducing bacteria (SRB). The robustness of the system was studied by increasing Zn, COD and sulfate loadings. Sulfate removal efficiency, which was 70% at 2g/L feed sulfate concentration, steadily decreased with increasing feed sulfate concentration and reached 40% at 10g/L. Over 99% Zn removal was attained due to the formation of zinc-sulfide precipitate. COD removal efficiency at 2g/L feed sulfate concentration was over 94%, whereas, it steadily decreased due to the accumulation of acetate at higher loadings. Alkalinity produced from acetate oxidation increased wastewater pH remarkably when feed sulfate concentration was 5g/L or lower. Electron flow from carbon oxidation to sulfate reduction averaged 83+/-13%. The rest of the electrons were most likely coupled with fermentative reactions as the amount of methane production was insignificant. The developed ANN model was very successful as an excellent to reasonable match was obtained between the measured and the predicted concentrations of sulfate (R=0.998), COD (R=0.993), acetate (R=0.976) and zinc (R=0.827) in the CSTR effluent.

  17. Dissecting CNBP, a zinc-finger protein required for neural crest development, in its structural and functional domains.

    Science.gov (United States)

    Armas, Pablo; Agüero, Tristán H; Borgognone, Mariana; Aybar, Manuel J; Calcaterra, Nora B

    2008-10-17

    Cellular nucleic-acid-binding protein (CNBP) plays an essential role in forebrain and craniofacial development by controlling cell proliferation and survival to mediate neural crest expansion. CNBP binds to single-stranded nucleic acids and displays nucleic acid chaperone activity in vitro. The CNBP family shows a conserved modular organization of seven Zn knuckles and an arginine-glycine-glycine (RGG) box between the first and second Zn knuckles. The participation of these structural motifs in CNBP biochemical activities has still not been addressed. Here, we describe the generation of CNBP mutants that dissect the protein into regions with structurally and functionally distinct properties. Mutagenesis approaches were followed to generate: (i) an amino acid replacement that disrupted the fifth Zn knuckle; (ii) N-terminal deletions that removed the first Zn knuckle and the RGG box, or the RGG box alone; and (iii) a C-terminal deletion that eliminated the three last Zn knuckles. Mutant proteins were overexpressed in Escherichia coli, purified, and used to analyze their biochemical features in vitro, or overexpressed in Xenopus laevis embryos to study their function in vivo during neural crest cell development. We found that the Zn knuckles are required, but not individually essential, for CNBP biochemical activities, whereas the RGG box is essential for RNA-protein binding and nucleic acid chaperone activity. Removal of the RGG box allowed CNBP to preserve a weak single-stranded-DNA-binding capability. A mutant mimicking the natural N-terminal proteolytic CNBP form behaved as the RGG-deleted mutant. By gain-of-function and loss-of-function experiments in Xenopus embryos, we confirmed the participation of CNBP in neural crest development, and we demonstrated that the CNBP mutants lacking the N-terminal region or the RGG box alone may act as dominant negatives in vivo. Based on these data, we speculate about the existence of a specific proteolytic mechanism for the

  18. Artificial Neural Network Modelling of Photodegradation in Suspension of Manganese Doped Zinc Oxide Nanoparticles under Visible-Light Irradiation

    Directory of Open Access Journals (Sweden)

    Yadollah Abdollahi

    2014-01-01

    Full Text Available The artificial neural network (ANN modeling of m-cresol photodegradation was carried out for determination of the optimum and importance values of the effective variables to achieve the maximum efficiency. The photodegradation was carried out in the suspension of synthesized manganese doped ZnO nanoparticles under visible-light irradiation. The input considered effective variables of the photodegradation were irradiation time, pH, photocatalyst amount, and concentration of m-cresol while the efficiency was the only response as output. The performed experiments were designed into three data sets such as training, testing, and validation that were randomly splitted by the software’s option. To obtain the optimum topologies, ANN was trained by quick propagation (QP, Incremental Back Propagation (IBP, Batch Back Propagation (BBP, and Levenberg-Marquardt (LM algorithms for testing data set. The topologies were determined by the indicator of minimized root mean squared error (RMSE for each algorithm. According to the indicator, the QP-4-8-1, IBP-4-15-1, BBP-4-6-1, and LM-4-10-1 were selected as the optimized topologies. Among the topologies, QP-4-8-1 has presented the minimum RMSE and absolute average deviation as well as maximum R-squared. Therefore, QP-4-8-1 was selected as final model for validation test and navigation of the process. The model was used for determination of the optimum values of the effective variables by a few three-dimensional plots. The optimum points of the variables were confirmed by further validated experiments. Moreover, the model predicted the relative importance of the variables which showed none of them was neglectable in this work.

  19. Complement-dependent pathogenicity of brain-specific antibodies in cerebrospinal fluid

    DEFF Research Database (Denmark)

    Asgari, Nasrin; Khorooshi, Reza; Lillevang, Søren T;

    2013-01-01

    The specificity and potential pathogenicity of autoantibodies vary between neurological diseases. It is often unclear whether their detection in cerebrospinal fluid (CSF) is a consequence or a cause of pathology. The goal was to test whether administration of brain-specific antibodies into CSF...

  20. Predictive value of brain-specific proteins in serum for neurodevelopmental outcome after birth asphyxia.

    Science.gov (United States)

    Nagdyman, Nicole; Grimmer, Ingrid; Scholz, Tristess; Muller, Christian; Obladen, Michael

    2003-08-01

    Brain-specific proteins have been used to detect cerebral injury after birth asphyxia. Previous investigations suggest that serum protein S-100beta, brain-specific creatine kinase (CK-BB), and neuron-specific enolase (NSE) are capable of identifying patients with a risk of developing hypoxic-ischemic encephalopathy. Whether detection of elevated serum concentrations of these proteins reflects long-term neurodevelopmental impairment remains to be investigated. We examined serum protein S-100beta, NSE, and CK-BB at 2, 6, 12, and 24 h after birth in 29 asphyxiated infants and 20 control infants. Neurodevelopmental follow-up examinations were performed at 20 mo of age using the German revision of the Griffiths scales for developmental assessment. Elevated concentrations of serum protein S-100beta, NSE, and CK-BB within 24 h after asphyxia did not correlate with long-term neurodevelopmental delay. We conclude that serum protein S-100beta, NSE, and CK-BB, sampled on the first day of life, is of limited value in predicting severe brain damage after birth asphyxia.

  1. Identification of brain-specific angiogenesis inhibitor 2 as an interaction partner of glutaminase interacting protein

    Energy Technology Data Exchange (ETDEWEB)

    Zencir, Sevil [Department of Biochemistry, Faculty of Science, Ege University, Izmir 35100 (Turkey); Ovee, Mohiuddin [Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849 (United States); Dobson, Melanie J. [Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada B3H 4R2 (Canada); Banerjee, Monimoy [Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849 (United States); Topcu, Zeki, E-mail: zeki.topcu@ege.edu.tr [Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Ege University, Izmir 35100 (Turkey); Mohanty, Smita, E-mail: mohansm@auburn.edu [Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849 (United States)

    2011-08-12

    Highlights: {yields} Brain-specific angiogenesis inhibitor 2 (BAI2) is a new partner protein for GIP. {yields} BAI2 interaction with GIP was revealed by yeast two-hybrid assay. {yields} Binding of BAI2 to GIP was characterized by NMR, CD and fluorescence. {yields} BAI2 and GIP binding was mediated through the C-terminus of BAI2. -- Abstract: The vast majority of physiological processes in living cells are mediated by protein-protein interactions often specified by particular protein sequence motifs. PDZ domains, composed of 80-100 amino acid residues, are an important class of interaction motif. Among the PDZ-containing proteins, glutaminase interacting protein (GIP), also known as Tax Interacting Protein TIP-1, is unique in being composed almost exclusively of a single PDZ domain. GIP has important roles in cellular signaling, protein scaffolding and modulation of tumor growth and interacts with a number of physiological partner proteins, including Glutaminase L, {beta}-Catenin, FAS, HTLV-1 Tax, HPV16 E6, Rhotekin and Kir 2.3. To identify the network of proteins that interact with GIP, a human fetal brain cDNA library was screened using a yeast two-hybrid assay with GIP as bait. We identified brain-specific angiogenesis inhibitor 2 (BAI2), a member of the adhesion-G protein-coupled receptors (GPCRs), as a new partner of GIP. BAI2 is expressed primarily in neurons, further expanding GIP cellular functions. The interaction between GIP and the carboxy-terminus of BAI2 was characterized using fluorescence, circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy assays. These biophysical analyses support the interaction identified in the yeast two-hybrid assay. This is the first study reporting BAI2 as an interaction partner of GIP.

  2. Important roles of brain-specific carnitine palmitoyltransferase and ceramide metabolism in leptin hypothalamic control of feeding%Important roles of brain-specific carnitine palmitoyltransferase and ceramide metabolism in leptin hypothalamic control of feeding

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In a recent issue of PNAS, Professor Wu Donghai of Guangzhou Institutes of Biomedicine and Health (GIBH) and his colleagues published a paper titled "Important roles of brain-specific carnitine palmitoyltransferase and ceramide metabolism in leptin hypothalamic control of feeding". Prof. Wu has receivedsustained support from NSFC since 2006.

  3. Organ, cellular, and subcellular localization of brain-specific anion transporter BSAT1.

    Science.gov (United States)

    Baklaushev, V P; Kardashova, K Sh; Gurina, O I; Yusubaliyeva, G M; Zorkina, Ya A; Chekhonin, V P

    2013-08-01

    Organ, cellular, and subcellular localization of brain-specific anion transporter BSAT1 was studied in rats using antibodies to the extracellular fragment (451-557 a.a). The antibodies were shown to recognize the antigen predominantly localized in the nervous tissue, tumors of glial origin, and primordial ovarian follicles. The absence of BSAT1 immunofluorescence signal in kidney and liver sections and accumulation of (125)I labeled antibodies to BSAT1 in these organs indicate that these antibodies do not cross-react with the most common isoforms of OATP expressed in these organs. Analysis of the cellular localization suggests that in the brain, BSAT1 is localized predominantly in astrocytes, but not in endothelial cells, as was previously reported. Laser scanning confocal microscopy with a set of relevant trackers revealed membrane localization of BSAT1. Taking into account the data on the of localization, we can conclude that antibodies to BSAT1 451-557 can be used for basic research of the transport of thyroxin and prostaglandins across the blood brain barrier and for testing the systems for targeted transport of diagnostic preparations and drugs across the blood brain barrier, e.g. to astroglial tumors.

  4. Simultaneous Automatic Electrochemical Detection of Zinc, Cadmium, Copper and Lead Ions in Environmental Samples Using a Thin-Film Mercury Electrode and an Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Jiri Kudr

    2014-12-01

    Full Text Available In this study a device for automatic electrochemical analysis was designed. A three electrodes detection system was attached to a positioning device, which enabled us to move the electrode system from one well to another of a microtitre plate. Disposable carbon tip electrodes were used for Cd(II, Cu(II and Pb(II ion quantification, while Zn(II did not give signal in this electrode configuration. In order to detect all mentioned heavy metals simultaneously, thin-film mercury electrodes (TFME were fabricated by electrodeposition of mercury on the surface of carbon tips. In comparison with bare electrodes the TMFEs had lower detection limits and better sensitivity. In addition to pure aqueous heavy metal solutions, the assay was also performed on mineralized rock samples, artificial blood plasma samples and samples of chicken embryo organs treated with cadmium. An artificial neural network was created to evaluate the concentrations of the mentioned heavy metals correctly in mixture samples and an excellent fit was observed (R2 = 0.9933.

  5. Artificial neural network (ANN) method for modeling of sunset yellow dye adsorption using zinc oxide nanorods loaded on activated carbon: Kinetic and isotherm study.

    Science.gov (United States)

    Maghsoudi, M; Ghaedi, M; Zinali, A; Ghaedi, A M; Habibi, M H

    2015-01-05

    In this research, ZnO nanoparticle loaded on activated carbon (ZnO-NPs-AC) was synthesized simply by a low cost and nontoxic procedure. The characterization and identification have been completed by different techniques such as SEM and XRD analysis. A three layer artificial neural network (ANN) model is applicable for accurate prediction of dye removal percentage from aqueous solution by ZnO-NRs-AC following conduction of 270 experimental data. The network was trained using the obtained experimental data at optimum pH with different ZnO-NRs-AC amount (0.005-0.015 g) and 5-40 mg/L of sunset yellow dye over contact time of 0.5-30 min. The ANN model was applied for prediction of the removal percentage of present systems with Levenberg-Marquardt algorithm (LMA), a linear transfer function (purelin) at output layer and a tangent sigmoid transfer function (tansig) in the hidden layer with 6 neurons. The minimum mean squared error (MSE) of 0.0008 and coefficient of determination (R(2)) of 0.998 were found for prediction and modeling of SY removal. The influence of parameters including adsorbent amount, initial dye concentration, pH and contact time on sunset yellow (SY) removal percentage were investigated and optimal experimental conditions were ascertained. Optimal conditions were set as follows: pH, 2.0; 10 min contact time; an adsorbent dose of 0.015 g. Equilibrium data fitted truly with the Langmuir model with maximum adsorption capacity of 142.85 mg/g for 0.005 g adsorbent. The adsorption of sunset yellow followed the pseudo-second-order rate equation.

  6. A hybrid artificial neural network and particle swarm optimization for prediction of removal of hazardous dye brilliant green from aqueous solution using zinc sulfide nanoparticle loaded on activated carbon

    Science.gov (United States)

    Ghaedi, M.; Ansari, A.; Bahari, F.; Ghaedi, A. M.; Vafaei, A.

    2015-02-01

    In the present study, zinc sulfide nanoparticle loaded on activated carbon (ZnS-NP-AC) simply was synthesized in the presence of ultrasound and characterized using different techniques such as SEM and BET analysis. Then, this material was used for brilliant green (BG) removal. To dependency of BG removal percentage toward various parameters including pH, adsorbent dosage, initial dye concentration and contact time were examined and optimized. The mechanism and rate of adsorption was ascertained by analyzing experimental data at various time to conventional kinetic models such as pseudo-first-order and second order, Elovich and intra-particle diffusion models. Comparison according to general criterion such as relative error in adsorption capacity and correlation coefficient confirm the usability of pseudo-second-order kinetic model for explanation of data. The Langmuir models is efficiently can explained the behavior of adsorption system to give full information about interaction of BG with ZnS-NP-AC. A multiple linear regression (MLR) and a hybrid of artificial neural network and partial swarm optimization (ANN-PSO) model were used for prediction of brilliant green adsorption onto ZnS-NP-AC. Comparison of the results obtained using offered models confirm higher ability of ANN model compare to the MLR model for prediction of BG adsorption onto ZnS-NP-AC. Using the optimal ANN-PSO model the coefficient of determination (R2) were 0.9610 and 0.9506; mean squared error (MSE) values were 0.0020 and 0.0022 for the training and testing data set, respectively.

  7. A hybrid artificial neural network and particle swarm optimization for prediction of removal of hazardous dye brilliant green from aqueous solution using zinc sulfide nanoparticle loaded on activated carbon.

    Science.gov (United States)

    Ghaedi, M; Ansari, A; Bahari, F; Ghaedi, A M; Vafaei, A

    2015-02-25

    In the present study, zinc sulfide nanoparticle loaded on activated carbon (ZnS-NP-AC) simply was synthesized in the presence of ultrasound and characterized using different techniques such as SEM and BET analysis. Then, this material was used for brilliant green (BG) removal. To dependency of BG removal percentage toward various parameters including pH, adsorbent dosage, initial dye concentration and contact time were examined and optimized. The mechanism and rate of adsorption was ascertained by analyzing experimental data at various time to conventional kinetic models such as pseudo-first-order and second order, Elovich and intra-particle diffusion models. Comparison according to general criterion such as relative error in adsorption capacity and correlation coefficient confirm the usability of pseudo-second-order kinetic model for explanation of data. The Langmuir models is efficiently can explained the behavior of adsorption system to give full information about interaction of BG with ZnS-NP-AC. A multiple linear regression (MLR) and a hybrid of artificial neural network and partial swarm optimization (ANN-PSO) model were used for prediction of brilliant green adsorption onto ZnS-NP-AC. Comparison of the results obtained using offered models confirm higher ability of ANN model compare to the MLR model for prediction of BG adsorption onto ZnS-NP-AC. Using the optimal ANN-PSO model the coefficient of determination (R(2)) were 0.9610 and 0.9506; mean squared error (MSE) values were 0.0020 and 0.0022 for the training and testing data set, respectively.

  8. Brain-specific ablation of Efr3a promotes adult hippocampal neurogenesis via the brain-derived neurotrophic factor pathway.

    Science.gov (United States)

    Qian, Qi; Liu, Qiuji; Zhou, Dongming; Pan, Hongyu; Liu, Zhiwei; He, Fangping; Ji, Suying; Wang, Dongpi; Bao, Wangxiao; Liu, Xinyi; Liu, Zhaoling; Zhang, Heng; Zhang, Xiaoqin; Zhang, Ling; Wang, Mingkai; Xu, Ying; Huang, Fude; Luo, Benyan; Sun, Binggui

    2017-02-13

    Efr3 is a newly identified plasma membrane protein and plays an important role in the phosphoinositide metabolism on the plasma membrane. However, although it is highly expressed in the brain, the functional significance of Efr3 in the brain is not clear. In the present study, we generated Efr3a(f/f) mice and then crossed them with Nestin-Cre mice to delete Efr3a, one of the Efr3 isoforms, specifically in the brain. We found that brain-specific ablation of Efr3a promoted adult hippocampal neurogenesis by increasing survival and maturation of newborn neurons without affecting their dendritic tree morphology. Moreover, the brain-derived neurotrophic factor (BDNF)-tropomyosin-related kinase B (TrkB) signaling pathway was significantly enhanced in the hippocampus of Efr3a-deficient mice, as reflected by increased expression of BDNF, TrkB, and the downstream molecules, including phospho-MAPK and phospho-Akt. Furthermore, the number of TUNEL(+) cells was decreased in the subgranular zone of dentate gyrus in Efr3a-deficient mice compared with that of control mice. Our data suggest that brain-specific deletion of Efr3a could promote adult hippocampal neurogenesis, presumably by upregulating the expression of BDNF and its receptor, TrkB, and therefore provide new insight into the roles of Efr3 in the brain.-Qian, Q., Liu, Q., Zhou, D., Pan, H., Liu, Z., He, F., Ji, S., Wang, D., Bao, W., Liu, X., Liu, Z., Zhang, H., Zhang, X., Zhang, L., Wang, M., Xu, Y., Huang, F., Luo, B., Sun B. Brain-specific ablation of Efr3a promotes adult hippocampal neurogenesis via the brain-derived neurotrophic factor pathway.

  9. Zinc: the neglected nutrient.

    Science.gov (United States)

    Shambaugh, G E

    1989-03-01

    Zinc was first recognized as essential for animals at the University of Illinois School of Agriculture in 1916, when it was found that zinc-deficient baby pigs were runty, developed dermatitis on their legs, and were sterile. Zinc deficiency was first recognized in man by Dr. Ananda Prasad of Detroit 26 years ago when he measured serum and hair zinc levels in young male Egyptian dwarfs who had failed to mature and were small in stature. By simply adding zinc to their regular diet, they grew in height and became sexually mature. It is now recognized that dwarfism in males is frequent around the Mediterranean, where wheat is the staple of life and has been grown for 4,000 years on the same soil, thereby resulting in the depletion of zinc. Professor Robert Henkin first suggested that zinc deficiency might cause hearing-nerve impairment. Assay of the soft tissues of the cochlea and vestibule revealed a zinc level higher than that of any other part of the body. Previously, the eye was considered to have the highest level of zinc of any organ. To diagnose zinc deficiency clinically, we use serum zinc assays made at the Mayo Clinic Trace Element Laboratory. With zinc supplementation in patients who are marginally zinc deficient, there has been improvement in tinnitus and sensorineural hearing loss in about one-third of elderly adults. We believe zinc deficiency is one causation of presbycusis; by recognizing and correcting it, a progressive hearing loss can be arrested.

  10. Is zinc a neuromodulator?

    Science.gov (United States)

    Kay, Alan R; Tóth, Katalin

    2008-01-01

    The vesicles of certain glutamatergic terminals in the mammalian forebrain are replete with ionic zinc. It is believed that during synaptic transmission zinc is released, binds to receptors on the pre- or postsynaptic membranes, and hence acts as a neuromodulator. Although exogenous zinc modulates a wide variety of channels, whether synaptic zinc transits across the synaptic cleft and alters the response of channels has been difficult to establish. We will review the evidence for zinc as a neuromodulator and propose diagnostic criteria for establishing whether it is indeed one. Moreover, we will delineate alternative ways in which zinc might act at synapses.

  11. Brain-specific noncoding RNAs are likely to originate in repeats and may play a role in up-regulating genes in cis

    DEFF Research Database (Denmark)

    Francescatto, Margherita; Vitezic, Morana; Heutink, Peter;

    2014-01-01

    . Dysregulation of specific long ncRNAs (lncRNAs) has been shown in neuro-developmental and neuro-degenerative diseases thus highlighting the importance of lncRNAs in brain function. Even though it is known that lncRNAs are expressed in cells at low levels in a tissue-specific manner, bioinformatics analyses...... in the vicinity of brain-specific ncRNAs are significantly up regulated in the brain. Investigations of repeat representation show that brain-specific ncRNAs are significantly more likely to originate in repeat regions especially DNA/TcMar-Tigger compared with non-tissue-specific ncRNAs. We find SINE...

  12. Zinc oxide overdose

    Science.gov (United States)

    Zinc oxide is an ingredient in many products. Some of these are certain creams and ointments used ... prevent or treat minor skin burns and irritation. Zinc oxide overdose occurs when someone eats one of ...

  13. Maternal zinc deficiency impairs brain nestin expression in prenatal and postnatal mice

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Effects of maternal dietary zinc deficiency on prenatal and postnatal brain development were investigated in ICR strain mice.From d 1 of pregnancy(E0)until postnatal d 20(P20),maternal mice were fed experimental diets that contained 1 mg Zn/kg/day(severe zinc deficient,SZD),5 mg Zn/kg/day(marginal zinc deficient,MZD),30 mg Zn/kg/day(zinc adequately supplied,ZA)or 100 mg Zn/kg/day(zinc supplemented,ZS and pair-fed,PF).Brains of offspring from these dietary groups were examined at various developmental stages for expression of nestin,an intermediate filament protein found in neural stem cells and young neurons,Immunocytochemistry showed nestin expression in neural tube 10.5 d post citrus(dpc)as well as in the cerebral cortex and neural tube from 10.5 dpc to postnatal d 10(P10).Nestin immunoreactivities in both brain and neural tube of those zinc-supplemented control groups(ZA,ZS,PF)were stronger than those in zinc-deficient groups(SZD and MZD).Western blot analysis confirmed that nestin levels in pooled brain extracts from each of the zinc-supplemented groups(ZA,ZS,PF)were much higher than those from the zinc-deficient groups(SZD and MZD)from 10.5 dpc to P10.Immunostaining and Western blots showed no detectable nestin in any of the experimental and control group brains after P20.These observations of an association between maternal zinc deficiency and decreased nestin protein levels in brains of offspring suggest that zinc deficiency suppresses development of neural stem cells,an effect which may lead to neuroanatomical and behavioral abnormalities in adults.

  14. Cadmium and zinc relationships

    Energy Technology Data Exchange (ETDEWEB)

    Elinder, C.; Piscator, M.

    1978-08-01

    Higher mammals, such as homo sapiens, accumulate zinc in kidney cortex almost equimolarly with cadmium. A different pattern seems to be present in liverthere is a limited increase of zinc in two species of large farm animals compared with a marked increase in the laboratory. In large farm animals, an equimolar increase of zinc with cadmium in renal cortex seems to indicate that the form of metallothionein that binds equal amounts of cadmium and zinc in present. Differences in cadmium and zinc relationships in large animals and humans compared with laboratory animals must be carefully considered. (4 graphs, 26 references)

  15. The brain-specific factor FEZ1 is a determinant of neuronal susceptibility to HIV-1 infection.

    LENUS (Irish Health Repository)

    Haedicke, Juliane

    2009-08-18

    Neurons are one of the few cell types in the human body that do not support HIV type-1 (HIV-1) replication. Although the lack of key receptors is a major obstacle to infection, studies suggest that additional functions inhibit virus replication to explain the exquisite resistance of neurons to HIV-1. However, specific neuronal factors that may explain this resistance remain to be discovered. In a screen for antiviral factors using a fibroblast line chemically mutagenized and selected for resistance to retroviral infection, we recently identified induction of rat FEZ1 (fasciculation and elongation protein zeta-1), a brain-specific protein, as the cause of this resistance. When exogenously expressed in nonneuronal cell lines rat FEZ1 blocked nuclear entry of retroviral DNA. Here, we demonstrate that among human brain cells, neurons naturally express high levels of FEZ1 compared to astrocytes or microglia cells and are correspondingly less susceptible to infection with pseudotyped HIV-1 that bypasses receptor-mediated viral entry. Demonstrating that endogenous FEZ1 was functionally important in the resistance of neurons to HIV-1 infection, siRNA-mediated knockdown of endogenous FEZ1 increased the infectivity of neurons while sensitive brain cell types like microglia became more resistant upon FEZ1 overexpression. In addition, FEZ1 expression was not induced in response to IFN treatment. As such, in contrast to other widely expressed, IFN-inducible antiviral factors, FEZ1 appears to represent a unique neuron-specific determinant of cellular susceptibility to infection in a cell type that is naturally resistant to HIV-1.

  16. Cadmium and zinc relationships.

    Science.gov (United States)

    Elinder, C G; Piscator, M

    1978-08-01

    Cadmium and zinc concentrations in kidney and liver have been measured under different exposure situations in different species including man. The results show that zinc increases almost equimolarly with cadmium in kidney after long-term low-level exposure to cadmium, e.g., in man, horse, pig, and lamb. In contrast, the increase of zinc follows that of cadmium to only a limited extent, e.g., in guinea pig, rabbit, rat, mouse, and chicks. In liver, the cadmium--zinc relationship seems to be reversed in such a way that zinc increases with cadmium more markedly in laboratory animals than in higher mammals. These differences between cadmium and zinc relationships in humans and large farm animals and those in commonly used laboratory animals must be considered carefully before experimental data on cadmium and zinc relationships in laboratory animals can be extrapolated to humans.

  17. Fusion of TTYH1 with the C19MC microRNA cluster drives expression of a brain-specific DNMT3B isoform in the embryonal brain tumor ETMR.

    Science.gov (United States)

    Kleinman, Claudia L; Gerges, Noha; Papillon-Cavanagh, Simon; Sin-Chan, Patrick; Pramatarova, Albena; Quang, Dong-Anh Khuong; Adoue, Véronique; Busche, Stephan; Caron, Maxime; Djambazian, Haig; Bemmo, Amandine; Fontebasso, Adam M; Spence, Tara; Schwartzentruber, Jeremy; Albrecht, Steffen; Hauser, Peter; Garami, Miklos; Klekner, Almos; Bognar, Laszlo; Montes, Jose-Luis; Staffa, Alfredo; Montpetit, Alexandre; Berube, Pierre; Zakrzewska, Magdalena; Zakrzewski, Krzysztof; Liberski, Pawel P; Dong, Zhifeng; Siegel, Peter M; Duchaine, Thomas; Perotti, Christian; Fleming, Adam; Faury, Damien; Remke, Marc; Gallo, Marco; Dirks, Peter; Taylor, Michael D; Sladek, Robert; Pastinen, Tomi; Chan, Jennifer A; Huang, Annie; Majewski, Jacek; Jabado, Nada

    2014-01-01

    Embryonal tumors with multilayered rosettes (ETMRs) are rare, deadly pediatric brain tumors characterized by high-level amplification of the microRNA cluster C19MC. We performed integrated genetic and epigenetic analyses of 12 ETMR samples and identified, in all cases, C19MC fusions to TTYH1 driving expression of the microRNAs. ETMR tumors, cell lines and xenografts showed a specific DNA methylation pattern distinct from those of other tumors and normal tissues. We detected extreme overexpression of a previously uncharacterized isoform of DNMT3B originating at an alternative promoter that is active only in the first weeks of neural tube development. Transcriptional and immunohistochemical analyses suggest that C19MC-dependent DNMT3B deregulation is mediated by RBL2, a known repressor of DNMT3B. Transfection with individual C19MC microRNAs resulted in DNMT3B upregulation and RBL2 downregulation in cultured cells. Our data suggest a potential oncogenic re-engagement of an early developmental program in ETMR via epigenetic alteration mediated by an embryonic, brain-specific DNMT3B isoform.

  18. 改进型M-P神经网络在能量色散X荧光分析测定铅锌矿元素含量的应用研究%Research on the Application of Improved M-P Neural Network to the Determination of Lead and Zinc Ore Element Contents by Energy Disperse X-Ray Fluorescence Analysis

    Institute of Scientific and Technical Information of China (English)

    李飞; 葛良全; 张庆贤; 谷懿; 万志雄; 李王燕

    2012-01-01

    以新疆西天山铅锌矿样品的Cu,Fe,Pb等元素X荧光测量数据做训练样本,McCulloch-Pitts神经网络(M-P神经网络)为基础,基体效应为依据,建立新的神经网络模型对Zn进行定量预测.结果预测值与测量值的相对误差在<5%.此方法可较准确,快速的应用于现场X荧光测定,为X荧光光谱信息修正提供一种新方法.%Because of different constraints (such as different kinds of measurable elements, characteristic X-ray energy, changes in matrix composition, etc ), usually it's not easy to get accurate information of elements, resulting in mistakes in later data analysis of energy disperse X-ray fluorescence measurement The method is based on McCulloch-Pitts neural network (M-P neural network), according to matrix effect, to establish a new neural network model for quantitative forecasting of Zn by taking the data of X-ray fluorescence measurements of Cu, Fe, Pb, etc in lead-zinc mine in western Tianshan as the training sample. The relative error between predicted value and measured value is less than 5%. This method can be more accurate and rapid for X-ray fluorescence; it provides a new approach to correcting information of X-ray fluorescence.

  19. [Zinc and type 2 diabetes].

    Science.gov (United States)

    Fukunaka, Ayako; Fujitani, Yoshio

    2016-07-01

    Pancreatic β cells contain the highest amount of zinc among cells within the human body, and hence, the relationship between zinc and diabetes has been a topic of great interest. While many studies demonstrating possible involvement of zinc deficiency in diabetes have been reported, precise mechanisms how zinc regulates glucose metabolism are still far from understood. Recent studies revealed that zinc can transmit signals that are driven by a variety of zinc transporters in a tissue and cell-type specific manner and deficiency in some zinc transporters may cause human diseases. Here, we review the role of zinc in metabolism particularly focusing on the emerging role of zinc transporters in diabetes.

  20. Improved zinc electrode and rechargeable zinc-air battery

    Science.gov (United States)

    Ross, P.N. Jr.

    1988-06-21

    The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

  1. Chelators for investigating zinc metalloneurochemistry.

    Science.gov (United States)

    Radford, Robert J; Lippard, Stephen J

    2013-04-01

    The physiology and pathology of mobile zinc signaling has become an important topic in metalloneurochemistry. To study the action of mobile zinc effectively, specialized tools are required that probe the temporal and positional changes of zinc ions within live tissue and cells. In the present article we describe the design and implementation of selective zinc chelators as antagonists to interrogate the function of mobile zinc, with an emphasis on the pools of vesicular zinc in the terminals of hippocampal mossy fiber buttons.

  2. Exploring zinc coordination in novel zinc battery electrolytes.

    Science.gov (United States)

    Kar, Mega; Winther-Jensen, Bjorn; Forsyth, Maria; MacFarlane, Douglas R

    2014-06-14

    The coordination of zinc ions by tetraglyme has been investigated here to support the development of novel electrolytes for rechargeable zinc batteries. Zn(2+) reduction is electrochemically reversible from tetraglyme. The spectroscopic data, molar conductivity and thermal behavior as a function of zinc composition, between mole ratios [80 : 20] and [50 : 50] [tetraglyme : zinc chloride], all suggest that strong interactions take place between chloro-zinc complexes and tetraglyme. Varying the concentration of zinc chloride produces a range of zinc-chloro species (ZnClx)(2-x) in solution, which hinder full interaction between the zinc ion and tetraglyme. Both the [70 : 30] and [50 : 50] mixtures are promising electrolyte candidates for reversible zinc batteries, such as the zinc-air device.

  3. Cytochrome c oxidase response to changes in cerebral oxygen delivery in the adult brain shows higher brain-specificity than haemoglobin ☆

    OpenAIRE

    Kolyva, Christina; Ghosh, Arnab; Tachtsidis, Ilias; Highton, David; Chris E Cooper; Smith, Martin; Elwell, Clare E.

    2014-01-01

    The redox state of cerebral mitochondrial cytochrome c oxidase monitored with near-infrared spectroscopy (Δ[oxCCO]) is a signal with strong potential as a non-invasive, bedside biomarker of cerebral metabolic status. We hypothesised that the higher mitochondrial density of brain compared to skin and skull would lead to evidence of brain-specificity of the Δ[oxCCO] signal when measured with a multi-distance near-infrared spectroscopy (NIRS) system. Measurements of Δ[oxCCO] as well as of concen...

  4. LEVELS OF BRAIN-SPECIFIC S-100B PROTEIN, SPECIFIC ANTIBODIES AND CYTOKINE PROFILE IN THE PATIENTS WITH ALCOHOL-INDUCED DELIRIUM STATES

    Directory of Open Access Journals (Sweden)

    N. N. Tsybikov

    2008-01-01

    Full Text Available Abstract. Present article deals with our results concerning brain-specific S-100B protein levels, anti-S-100B autoantibodies of IgM and IgG classes, like as cytokine profiles of blood serum and cerebrospinal fluid in the patients with alcohol-induced delirium state. The results obtained provide an evidence of association between alcoholic psychosis and destruction of brain tissue, development of autoimmune reactions and altered cytokine status, thus, probably, resulting into disintegration of immune and neuroendocrine systems.

  5. Zinc level and obesity

    Directory of Open Access Journals (Sweden)

    Doaa S.E. Zaky

    2013-01-01

    Conclusion Plasma zinc concentration in obese individuals showed an inverse relationship with the waist circumference and BMI as well as serum low-density lipoprotein-cholesterol and correlated positively with high-density lipoprotein.

  6. Zinc electrode and rechargeable zinc-air battery

    Science.gov (United States)

    Ross, Jr., Philip N.

    1989-01-01

    An improved zinc electrode is disclosed for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed which utilizes the improved zinc electrode and further includes an alkaline electrolyte within said battery circulating through the passageways in the zinc electrode and an external electrolyte circulation means which has an electrolyte reservoir external to the battery case including filter means to filter solids out of the electrolyte as it circulates to the external reservoir and pump means for recirculating electrolyte from the external reservoir to the zinc electrode.

  7. Zinc level and obesity

    OpenAIRE

    Doaa S.E Zaky; Eman A Sultan; Mahmoud F Salim; Rana S Dawod

    2013-01-01

    Background Obesity is a chronic condition that is associated with disturbances in the metabolism of zinc. Therefore, the aim of this study was to investigate the relationship between serum zinc level and different clinical and biochemical parameters in obese individuals. Patients and methods Twenty-four individuals with BMI more than 30 kg/m 2 and 14 healthy controls (BMI < 24 kg/m 2 ) were assessed for BMI and waist circumference using anthropometric measurements. Colorimetric tes...

  8. Flux-measuring approach of high temperature metal liquid based on BP neural networks

    Institute of Scientific and Technical Information of China (English)

    胡燕瑜; 桂卫华; 李勇刚

    2003-01-01

    A soft-measuring approach is presented to measure the flux of liquid zinc with high temperature andcausticity. By constructing mathematical model based on neural networks, weighing the mass of liquid zinc, the fluxof liquid zinc is acquired indirectly, the measuring on line and flux control are realized. Simulation results and indus-trial practice demonstrate that the relative error between the estimated flux value and practical measured flux value islower than 1.5%, meeting the need of industrial process.

  9. Treatment of zinc deficiency without zinc fortification

    Institute of Scientific and Technical Information of China (English)

    Donald OBERLEAS; Barbara F. HARLAND

    2008-01-01

    Zinc (Zn) deficiency in animals became of interest until the 1950s. In this paper, progresses in researches on physi-ology of Zn deficiency in animals, phytate effect on bioavailability of Zn, and role of phytase in healing Zn deficiency of animals were reviewed. Several studies demonstrated that Zn is recycled via the pancreas; the problem of Zn deficiency was controlled by Zn homeostasis. The endogenous secretion of Zn is considered as an important factor influencing Zn deficiency, and the critical molar ratio is 10. Phytate (inositol hexaphosphate) constituted up to 90% of the organically bound phosphorus in seeds. Great improvement has been made in recent years on isolating and measuring phytate, and its structure is clear. Phytate is considered to reduce Zn bioavailability in animal. Phytase is the enzyme that hydrolyzes phytate and is present in yeast, rye bran, wheat bran, barley, triticale, and many bacteria and fungi. Zinc nutrition and bioavailability can be enhanced by addition of phytase to animal feeds. Therefore, using phytase as supplements, the most prevalent Zn deficiency in animals may be effectively corrected without the mining and smelting of several tons of zinc daily needed to correct this deficiency by fortification worldwide.

  10. The bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens

    OpenAIRE

    Veldkamp, T.; Diepen, van, C.A.; Bikker, P.

    2014-01-01

    Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR Livestock Research to determine the bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens. A precise estimate of the bioavailability of zinc sources is required both for fulf...

  11. Zinc deficiency in the 11 day rat embryo: a scanning and transmission electron microscope study

    Energy Technology Data Exchange (ETDEWEB)

    Harding, A.J.; Dreosti, I.E.; Tulsi, R.S.

    1988-01-01

    Zinc deficient rat embryos were obtained on the 11th day of pregnancy and examined by scanning and transmission electron microscopy. Scanning electron microscopy revealed an increase in the number of deformed embryos, as well as embryonic growth retardation. In addition, the epithelium of zinc deficient embryos displayed a marked increase in surface microvilli, as well as the presence of blebbing. Transmission electron microscopy indicated extensive cell death in the neural epithelium which was apparently more severely damaged by zinc deficiency than were mesenchymal cells. Mitochondrial cristae were affected to a greater degree than any other membrane of the cell and cristael disintegration appeared to represent the principal cellular lesion preceding necrosis of neural cells and neural tube teratology. 29 references, 4 figures, 1 table.

  12. Brain-Specific Cytoskeletal Damage Markers in Cerebrospinal Fluid: Is There a Common Pattern between Amyotrophic Lateral Sclerosis and Primary Progressive Multiple Sclerosis?

    Directory of Open Access Journals (Sweden)

    Ahmed Abdelhak

    2015-07-01

    Full Text Available Many neurodegenerative disorders share a common pathophysiological pathway involving axonal degeneration despite different etiological triggers. Analysis of cytoskeletal markers such as neurofilaments, protein tau and tubulin in cerebrospinal fluid (CSF may be a useful approach to detect the process of axonal damage and its severity during disease course. In this article, we review the published literature regarding brain-specific CSF markers for cytoskeletal damage in primary progressive multiple sclerosis and amyotrophic lateral sclerosis in order to evaluate their utility as a biomarker for disease progression in conjunction with imaging and histological markers which might also be useful in other neurodegenerative diseases associated with affection of the upper motor neurons. A long-term benefit of such an approach could be facilitating early diagnostic and prognostic tools and assessment of treatment efficacy of disease modifying drugs.

  13. Brain-Specific Cytoskeletal Damage Markers in Cerebrospinal Fluid: Is There a Common Pattern between Amyotrophic Lateral Sclerosis and Primary Progressive Multiple Sclerosis?

    Science.gov (United States)

    Abdelhak, Ahmed; Junker, Andreas; Brettschneider, Johannes; Kassubek, Jan; Ludolph, Albert C; Otto, Markus; Tumani, Hayrettin

    2015-07-31

    Many neurodegenerative disorders share a common pathophysiological pathway involving axonal degeneration despite different etiological triggers. Analysis of cytoskeletal markers such as neurofilaments, protein tau and tubulin in cerebrospinal fluid (CSF) may be a useful approach to detect the process of axonal damage and its severity during disease course. In this article, we review the published literature regarding brain-specific CSF markers for cytoskeletal damage in primary progressive multiple sclerosis and amyotrophic lateral sclerosis in order to evaluate their utility as a biomarker for disease progression in conjunction with imaging and histological markers which might also be useful in other neurodegenerative diseases associated with affection of the upper motor neurons. A long-term benefit of such an approach could be facilitating early diagnostic and prognostic tools and assessment of treatment efficacy of disease modifying drugs.

  14. Brain-specific inactivation of the Crhr1 gene inhibits post-dependent and stress-induced alcohol intake, but does not affect relapse-like drinking

    DEFF Research Database (Denmark)

    Molander, Anna; Vengeliene, Valentina; Heilig, Markus;

    2012-01-01

    Corticotropin-releasing hormone (CRH) and its receptor, CRH receptor-1 (CRHR1), have a key role in alcoholism. Especially, post-dependent and stress-induced alcohol intake involve CRH/CRHR1 signaling within extra-hypothalamic structures, but a contribution of the hypothalamic-pituitary-adrenal (HPA......) axis activity might be involved as well. Here we examined the role of CRHR1 in various drinking conditions in relation to HPA and extra-HPA sites, and studied relapse-like drinking behavior in the alcohol deprivation model (ADE). To dissect CRH/CRHR1 extra-HPA and HPA signaling on a molecular level......, a conditional brain-specific Crhr1-knockout (Crhr1(NestinCre)) and a global knockout mouse line were studied for basal alcohol drinking, stress-induced alcohol consumption, deprivation-induced intake, and escalated alcohol consumption in the post-dependent state. In a second set of experiments, we tested CRHR1...

  15. Zinc Determination in Pleural Fluid

    OpenAIRE

    Nazan DEMİR; DEMİR, Yaşar

    2000-01-01

    In this study, an enzymatic zinc determination method was applied to pleural fluid, the basis of which was the regaining of the activity of apo carbonic anhydrase by the zinc present in the sample. The method was used for pleural fluid zinc determination in order to show the application to body fluids other than serum. For this purpose, pleural fluids were obtained from 20 patients and zinc concentrations were determined. Carbonic anhydrase was purified by affinity chromatography from bovine ...

  16. A brain-specific gene cluster isolated from the region of the mouse obesity locus is expressed in the adult hypothalamus and during mouse development

    Energy Technology Data Exchange (ETDEWEB)

    Laig-Webster, M.; Lim, M.E.; Chehab, F.F. [Univ. of California, San Francisco, CA (United States)

    1994-09-01

    The molecular defect underlying an autosomal recessive form of genetic obesity in a classical mouse model C57 BL/6J-ob/ob has not yet been elucidated. Whereas metabolic and physiological disturbances such as diabetes and hypertension are associated with obesity, the site of expression and the nature of the primary lesion responsible for this cascade of events remains elusive. Our efforts aimed at the positional cloning of the ob gene by YAC contig mapping and gene identification have resulted in the cloning of a brain-specific gene cluster from the ob critical region. The expression of this gene cluster is remarkably complex owing to the multitude of brain-specific mRNA transcripts detected on Northern blots. cDNA cloning of these transcripts suggests that they are expressed from different genes as well as by alternate splicing mechanisms. Furthermore, the genomic organization of the cluster appears to consist of at least two identical promoters displaying CpG islands characteristic of housekeeping genes, yet clearly involving tissue-specific expression. Sense and anti-sense synthetic RNA probes were derived from a common DNA sequence on 3 cDNA clones and hybridized to 8-16 days mouse embryonic stages and mouse adult brain sections. Expression in development was noticeable as of the 11th day of gestation and confined to the central nervous system mainly in the telencephalon and spinal cord. Coronal and sagittal sections of the adult mouse brain showed expression only in 3 different regions of the brain stem. In situ hybridization to mouse hypothalamus sections revealed the presence of a localized and specialized group of cells expressing high levels of mRNA, suggesting that this gene cluster may also be involved in the regulation of hypothalamic activities. The hypothalamus has long been hypothesized as a primary candidate tissue for the expression of the obesity gene mainly because of its well-established role in the regulation of energy metabolism and food intake.

  17. The bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens

    NARCIS (Netherlands)

    Veldkamp, T.; Diepen, van J.T.M.; Bikker, P.

    2014-01-01

    Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR Live

  18. Zinc Phosphide Poisoning

    Directory of Open Access Journals (Sweden)

    Erdal Doğan

    2014-01-01

    Full Text Available Zinc phosphide has been used widely as a rodenticide. Upon ingestion, it gets converted to phosphine gas in the body, which is subsequently absorbed into the bloodstream through the stomach and the intestines and gets captured by the liver and the lungs. Phosphine gas produces various metabolic and nonmetabolic toxic effects. Clinical symptoms are circulatory collapse, hypotension, shock symptoms, myocarditis, pericarditis, acute pulmonary edema, and congestive heart failure. In this case presentation, we aim to present the intensive care process and treatment resistance of a patient who ingested zinc phosphide for suicide purposes.

  19. Environmental risk limits for zinc

    NARCIS (Netherlands)

    Bodar CWM; SEC

    2007-01-01

    Environmental Riks Limits (ERLs) were derived for zinc. ERLs serve as advisory values to set environmental quality standards in the Netherlands. The ERLs for zinc closely follow the outcomes of earlier discussions on zinc within the Water Framework Directive and EC Regulation 793/93. The ERLs refer

  20. Environmental risk limits for zinc

    NARCIS (Netherlands)

    Bodar CWM; SEC

    2007-01-01

    Environmental Riks Limits (ERLs) were derived for zinc. ERLs serve as advisory values to set environmental quality standards in the Netherlands. The ERLs for zinc closely follow the outcomes of earlier discussions on zinc within the Water Framework Directive and EC Regulation 793/93. The ERLs ref

  1. Doped zinc oxide microspheres

    Science.gov (United States)

    Arnold, Jr., Wesley D.; Bond, Walter D.; Lauf, Robert J.

    1993-01-01

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel.

  2. Creep Resistant Zinc Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Frank E. Goodwin

    2002-12-31

    This report covers the development of Hot Chamber Die Castable Zinc Alloys with High Creep Strengths. This project commenced in 2000, with the primary objective of developing a hot chamber zinc die-casting alloy, capable of satisfactory service at 140 C. The core objectives of the development program were to: (1) fill in missing alloy data areas and develop a more complete empirical model of the influence of alloy composition on creep strength and other selected properties, and (2) based on the results from this model, examine promising alloy composition areas, for further development and for meeting the property combination targets, with the view to designing an optimized alloy composition. The target properties identified by ILZRO for an improved creep resistant zinc die-casting alloy were identified as follows: (1) temperature capability of 1470 C; (2) creep stress of 31 MPa (4500 psi); (3) exposure time of 1000 hours; and (4) maximum creep elongation under these conditions of 1%. The project was broadly divided into three tasks: (1) Task 1--General and Modeling, covering Experimental design of a first batch of alloys, alloy preparation and characterization. (2) Task 2--Refinement and Optimization, covering Experimental design of a second batch of alloys. (3) Task 3--Creep Testing and Technology transfer, covering the finalization of testing and the transfer of technology to the Zinc industry should have at least one improved alloy result from this work.

  3. Zinc in Multiple Sclerosis

    DEFF Research Database (Denmark)

    Bredholt, Mikkel; Frederiksen, Jette Lautrup

    2016-01-01

    In the last 35 years, zinc (Zn) has been examined for its potential role in the disease multiple sclerosis (MS). This review gives an overview of the possible role of Zn in the pathogenesis of MS as well as a meta-analysis of studies having measured Zn in serum or plasma in patients with MS...

  4. Studies on nanocrystalline zinc coating

    Indian Academy of Sciences (India)

    H B Muralidhara; Y Arthoba Naik

    2008-08-01

    Nano zinc coatings were deposited on mild steel by electrodeposition. The effect of additive on the morphology of crystal size on zinc deposit surface and corrosion properties were investigated. Corrosion tests were performed for dull zinc deposits and bright zinc deposits in aqueous NaCl solution (3.5 wt.%) using electrochemical measurements. The results showed that addition of additive in the deposition process of zinc significantly increased the corrosion resistance. The surface morphology of the zinc deposits was studied by scanning electron microscopy (SEM). The preferred orientation and average size of the zinc electrodeposited particles were obtained by X-ray diffraction analysis. The particles size was also characterized by TEM analysis.

  5. Interaction Between Yeasts and Zinc

    Science.gov (United States)

    Nicola, Raffaele De; Walker, Graeme

    Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

  6. Does the oral zinc tolerance test measure zinc absorption

    Energy Technology Data Exchange (ETDEWEB)

    Valberg, L.S.; Flanagan, P.R.; Brennan, J.; Chamberlain, M.J.

    1985-01-01

    Increases in plasma zinc concentration were compared with radiozinc absorption after oral test doses. Ten healthy, fasting subjects were each given 385 mumol zinc chloride (25 mg Zn) labelled with 0.5 muCi /sup 65/ZnCl/sub 2/ and a non-absorbed marker, /sup 51/CrCl/sub 3/, dissolved in 100 ml of water; another 10 persons were given 354 mumol zinc chloride and 125 g of minced turkey containing 31 mumol zinc also labelled with /sup 65/Zn and /sup 51/Cr. Measurements were made of plasma zinc concentration at hourly intervals for 5 hours, radiozinc absorption by stool counting of unabsorbed radioactivity 12-36 hours later, and radiozinc retention by whole body counting at 7 days. The mean percentage of radiozinc absorbed and retained in the body from the two test meals was found to be identical (42%). In contrast the increased area under the plasma zinc curve up to 5 hours after the turkey meal, 28 +/- 9 mumol/L (mean +/- SD) was significantly less than that for zinc chloride alone, 47 +/- 15 mumol/L, p less than 0.005. Despite this difference, a good correlation was found between the area under the plasma zinc curve and /sup 65/Zn absorption in individual subjects after each meal. The discrepancy between the results of zinc absorption derived from the plasma zinc curve and /sup 65/Zn absorption for the liquid and solid test meals was most likely explained by binding of zinc to food and delayed gastric emptying of the solid meal. With a test meal of turkey meat at least this dampened the plasma appearance of zinc but did not affect its overall absorption.

  7. Pinacol Coupling Reactions Catalyzed by Active Zinc

    Institute of Scientific and Technical Information of China (English)

    Hui ZHAO; Wei DENG; Qing Xiang GUO

    2005-01-01

    Pinacol coupling reactions catalyzed by active zinc revealed high activity and extensive suitability. The efficiency of the reaction was improved apparently owing to decreasing reductive potential of zinc. In addition, the results indicated that the zinc activity has a direct relation to the coupling reactivity compared to untreated zinc or other general active zinc.

  8. Low Expression of Slit2 and Robo1 is Associated with Poor Prognosis and Brain-specific Metastasis of Breast Cancer Patients.

    Science.gov (United States)

    Qin, Fengxia; Zhang, Huikun; Ma, Li; Liu, Xiaoli; Dai, Kun; Li, Wenliang; Gu, Feng; Fu, Li; Ma, Yongjie

    2015-09-24

    Brain metastasis is a significant unmet clinical problem in breast cancer treatment. It is always associated with poor prognosis and high morbidity. Recently, Slit2/Robo1 pathway has been demonstrated to be involved in the progression of breast carcinoma. However, until present, there are no convincing reports that suggest whether the Slit2/Robo1 axis has any role in brain metastasis of breast cancer. In this study, we investigated the correlation between Slit2/Robo1 signaling and breast cancer brain metastasis for the first time. Our results demonstrated that (1) Invasive ductal carcinoma patients with low expression of Slit2 or Robo1 exhibited worse prognosis and brain-specific metastasis, but not liver, bone or lung. (2) Lower expression of Slit2 and Robo1 were observed in patients with brain metastasis, especially in their brain metastasis tumors, compared with patients without brain metastasis. (3) The interval from diagnosis of breast cancer to brain metastasis and brain metastasis to death were both much shorter in patients with low expression of Slit2 or Robo1 compared with the high expression group. Overall, our findings indicated that Slit2/Robo1 axis possibly be regarded as a significant clinical parameter for predicting brain metastasis in breast cancer patients.

  9. Chronic restraint stress impairs neurogenesis and hippocampus-dependent fear memory in mice: possible involvement of a brain-specific transcription factor Npas4.

    Science.gov (United States)

    Yun, Jaesuk; Koike, Hiroyuki; Ibi, Daisuke; Toth, Erika; Mizoguchi, Hiroyuki; Nitta, Atsumi; Yoneyama, Masanori; Ogita, Kiyokazu; Yoneda, Yukio; Nabeshima, Toshitaka; Nagai, Taku; Yamada, Kiyofumi

    2010-09-01

    Neurogenesis in the hippocampus occurs throughout life in a wide range of species and could be associated with hippocampus-dependent learning and memory. Stress is well established to seriously perturb physiological/psychological homeostasis and affect hippocampal function. In the present study, to investigate the effect of chronic restraint stress in early life on hippocampal neurogenesis and hippocampus-dependent memory, 3-week-old mice were subjected to restraint stress 6 days a week for 4 weeks. The chronic restraint stress significantly decreased the hippocampal volume by 6.3% and impaired hippocampal neurogenesis as indicated by the reduced number of Ki67-, 5-bromo-2'-deoxyuridine- and doublecortin-positive cells in the dentate gyrus. The chronic restraint stress severely impaired hippocampus-dependent contextual fear memory without affecting hippocampus-independent fear memory. The expression level of brain-specific transcription factor neuronal PAS domain protein 4 (Npas4) mRNA in the hippocampus was down-regulated by the restraint stress or by acute corticosterone treatment. Npas4 immunoreactivity was detected in progenitors, immature and mature neurons of the dentate gyrus in control and stressed mice. Our findings suggest that the chronic restraint stress decreases hippocampal neurogenesis, leading to an impairment of hippocampus-dependent fear memory in mice. Corticosterone-induced down-regulation of Npas4 expression may play a role in stress-induced impairment of hippocampal function.

  10. Two cytosolic puromycin-sensitive aminopeptidase isozymes in chicken brain: molecular homology to brain-specific 14-3-3 protein.

    Science.gov (United States)

    Hui, K S; Saito, M; Hui, M; Saito, M; Lajtha, A; Yamamoto, K; Osawa, T

    1993-05-01

    Two puromycin-sensitive aminopeptidase isozymes (PSA-I and PSA-II) were isolated from chicken brain cytosol by ammonium sulfate fractionation followed by column chromatography on Cellex D and AH-Sepharose 4B and separated on Bio-Gel HTP. Each was purified to homogeneity on Sephadex G-200, Arg-Tyr-AH-Sepharose, Bio-Gel HTP, and preparative gel electrophoresis. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, PSA-I appeared to be a monomer with a molecular mass of 105 kDa, and PSA-II to be composed of two subunits of 25 kDa and 100 kDa. The tryptic maps of 100 kDa and 105 kDa protein in HPLC are different in peak frequency, height, and composition. The internal peptide sequence of PSA-I has a considerable homology to PSA-II. Both isozymes have repeated copies of common peptide segments and have no significant sequence homology to other peptidases and proteinases. These thio and Co(2+)-activated isozymes have a neutral pH optimum and are inhibited by puromycin and bestatin. PSA-II is more sensitive to trypsin and heat treatment, has a lower Km to Met-enkephalin, and is more active on Arg BNA and Pro BNA. Our results suggest that PSA-I and PSA-II derive from translation of two RNAs of a new gene family related to the brain-specific 14-3-3 protein.

  11. Neural Networks

    Directory of Open Access Journals (Sweden)

    Schwindling Jerome

    2010-04-01

    Full Text Available This course presents an overview of the concepts of the neural networks and their aplication in the framework of High energy physics analyses. After a brief introduction on the concept of neural networks, the concept is explained in the frame of neuro-biology, introducing the concept of multi-layer perceptron, learning and their use as data classifer. The concept is then presented in a second part using in more details the mathematical approach focussing on typical use cases faced in particle physics. Finally, the last part presents the best way to use such statistical tools in view of event classifers, putting the emphasis on the setup of the multi-layer perceptron. The full article (15 p. corresponding to this lecture is written in french and is provided in the proceedings of the book SOS 2008.

  12. Chloroquine is a zinc ionophore.

    Directory of Open Access Journals (Sweden)

    Jing Xue

    Full Text Available Chloroquine is an established antimalarial agent that has been recently tested in clinical trials for its anticancer activity. The favorable effect of chloroquine appears to be due to its ability to sensitize cancerous cells to chemotherapy, radiation therapy, and induce apoptosis. The present study investigated the interaction of zinc ions with chloroquine in a human ovarian cancer cell line (A2780. Chloroquine enhanced zinc uptake by A2780 cells in a concentration-dependent manner, as assayed using a fluorescent zinc probe. This enhancement was attenuated by TPEN, a high affinity metal-binding compound, indicating the specificity of the zinc uptake. Furthermore, addition of copper or iron ions had no effect on chloroquine-induced zinc uptake. Fluorescent microscopic examination of intracellular zinc distribution demonstrated that free zinc ions are more concentrated in the lysosomes after addition of chloroquine, which is consistent with previous reports showing that chloroquine inhibits lysosome function. The combination of chloroquine with zinc enhanced chloroquine's cytotoxicity and induced apoptosis in A2780 cells. Thus chloroquine is a zinc ionophore, a property that may contribute to chloroquine's anticancer activity.

  13. Depleted zinc: Properties, application, production.

    Science.gov (United States)

    Borisevich, V D; Pavlov, A V; Okhotina, I A

    2009-01-01

    The addition of ZnO, depleted in the Zn-64 isotope, to the water of boiling water nuclear reactors lessens the accumulation of Co-60 on the reactor interior surfaces, reduces radioactive wastes and increases the reactor service-life because of the inhibitory action of zinc on inter-granular stress corrosion cracking. To the same effect depleted zinc in the form of acetate dihydrate is used in pressurized water reactors. Gas centrifuge isotope separation method is applied for production of depleted zinc on the industrial scale. More than 20 years of depleted zinc application history demonstrates its benefits for reduction of NPP personnel radiation exposure and combating construction materials corrosion.

  14. Zinc In CCl4 Toxicity

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective To investigate the protective effect of zinc in CCl4-induced hepatotoxicity. Methods Rats were treated with zinc acetate for four days. The zinc doses were 5 mg Zn/kg and 10 mg Zn/kg body weight respectively. Two groups of the zinc acetate-treated rats were later challenged with a single dose of CCl4 (1.5 mL/kg body weight). Results Compared to control animals, the plasma of rats treated with CCl4 showed hyperbilirubinaemia, hypoglycaemia, hypercreatinaemia and hypoproteinaemia. When the animals were however supplemented with zinc in form of zinc acetate before being dosed with CCl4, the 5 mg Zn/kg body weight of zinc acetate reversed the hypoproteinaemia induced by CCl4, whereas the 10mg Zn/kg body weight of zinc acetate reversed the hypoglycaemia, hyperbilimbinaemia and hypercreatinaemia induced by CCl4. Conclusion The 10mug Zn/kg body weight of zinc acetate is more consistent in protecting against CCl4 hepatotoxicity. The possible mechanisms of protection are highlighted.

  15. FGF Signaling Transforms Non-neural Ectoderm into Neural Crest

    OpenAIRE

    Yardley, Nathan; García-Castro, Martín I.

    2012-01-01

    The neural crest arises at the border between the neural plate and the adjacent non-neural ectoderm. It has been suggested that both neural and non-neural ectoderm can contribute to the neural crest. Several studies have examined the molecular mechanisms that regulate neural crest induction in neuralized tissues or the neural plate border. Here, using the chick as a model system, we address the molecular mechanisms by which non-neural ectoderm generates neural crest. We report that in respons...

  16. Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide.

    Science.gov (United States)

    Wegmüller, Rita; Tay, Fabian; Zeder, Christophe; Brnic, Marica; Hurrell, Richard F

    2014-02-01

    The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with (67)Zn and (70)Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6-71.0) and was not different from that from zinc gluconate with 60.9% (50.6-71.7). Absorption from zinc oxide at 49.9% (40.9-57.7) was significantly lower than from both other supplements (P zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov as NCT01576627.

  17. Inhibitory zinc-enriched terminals in mouse spinal cord

    DEFF Research Database (Denmark)

    Danscher, G; Jo, S M; Varea, E;

    2001-01-01

    The ultrastructural localization of zinc transporter-3, glutamate decarboxylase and zinc ions in zinc-enriched terminals in the mouse spinal cord was studied by zinc transporter-3 and glutamate decarboxylase immunohistochemistry and zinc selenium autometallography, respectively.The distribution...

  18. The brain-specific RasGEF very-KIND is required for normal dendritic growth in cerebellar granule cells and proper motor coordination

    Science.gov (United States)

    Hayashi, Kanehiro; Furuya, Asako; Sakamaki, Yuriko; Akagi, Takumi; Shinoda, Yo; Sadakata, Tetsushi; Hashikawa, Tsutomu; Shimizu, Kazuki; Minami, Haruka; Sano, Yoshitake; Nakayama, Manabu

    2017-01-01

    Very-KIND/Kndc1/KIAA1768 (v-KIND) is a brain-specific Ras guanine nucleotide exchange factor carrying two sets of the kinase non-catalytic C-lobe domain (KIND), and is predominantly expressed in cerebellar granule cells. Here, we report the impact of v-KIND deficiency on dendritic and synaptic growth in cerebellar granule cells in v-KIND knockout (KO) mice. Furthermore, we evaluate motor function in these animals. The gross anatomy of the cerebellum, including the cerebellar lobules, layered cerebellar cortex and densely-packed granule cell layer, in KO mice appeared normal, and was similar to wild-type (WT) mice. However, KO mice displayed an overgrowth of cerebellar granule cell dendrites, compared with WT mice, resulting in an increased number of dendrites, dendritic branches and terminals. Immunoreactivity for vGluT2 (a marker for excitatory presynapses of mossy fiber terminals) was increased in the cerebellar glomeruli of KO mice, compared with WT mice. The postsynaptic density around the terminals of mossy fibers was also increased in KO mice. Although there were no significant differences in locomotor ability between KO and WT animals in their home cages or in the open field, young adult KO mice had an increased grip strength and a tendency to exhibit better motor performance in balance-related tests compared with WT animals. Taken together, our results suggest that v-KIND is required for compact dendritic growth and proper excitatory synaptic connections in cerebellar granule cells, which are necessary for normal motor coordination and balance. PMID:28264072

  19. Systematic analysis of transcription-level effects of neurodegenerative diseases on human brain metabolism by a newly reconstructed brain-specific metabolic network

    Directory of Open Access Journals (Sweden)

    Mustafa Sertbaş

    2014-01-01

    Full Text Available Network-oriented analysis is essential to identify those parts of a cell affected by a given perturbation. The effect of neurodegenerative perturbations in the form of diseases of brain metabolism was investigated by using a newly reconstructed brain-specific metabolic network. The developed stoichiometric model correctly represents healthy brain metabolism, and includes 630 metabolic reactions in and between astrocytes and neurons, which are controlled by 570 genes. The integration of transcriptome data of six neurodegenerative diseases (Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, multiple sclerosis, schizophrenia with the model was performed to identify reporter features specific and common for these diseases, which revealed metabolites and pathways around which the most significant changes occur. The identified metabolites are potential biomarkers for the pathology of the related diseases. Our model indicated perturbations in oxidative stress, energy metabolism including TCA cycle and lipid metabolism as well as several amino acid related pathways, in agreement with the role of these pathways in the studied diseases. The computational prediction of transcription factors that commonly regulate the reporter metabolites was achieved through binding-site analysis. Literature support for the identified transcription factors such as USF1, SP1 and those from FOX families are known from the literature to have regulatory roles in the identified reporter metabolic pathways as well as in the neurodegenerative diseases. In essence, the reconstructed brain model enables the elucidation of effects of a perturbation on brain metabolism and the illumination of possible machineries in which a specific metabolite or pathway acts as a regulatory spot for cellular reorganization.

  20. Nanostructures of zinc oxide

    Directory of Open Access Journals (Sweden)

    Zhong Lin Wang

    2004-06-01

    Full Text Available Zinc oxide (ZnO is a unique material that exhibits semiconducting, piezoelectric, and pyroelectric multiple properties. Using a solid-vapor phase thermal sublimation technique, nanocombs, nanorings, nanohelixes/nanosprings, nanobows, nanobelts, nanowires, and nanocages of ZnO have been synthesized under specific growth conditions. These unique nanostructures unambiguously demonstrate that ZnO is probably the richest family of nanostructures among all materials, both in structures and properties. The nanostructures could have novel applications in optoelectronics, sensors, transducers, and biomedical science because it is bio-safe.

  1. El zinc: oligoelemento esencial

    Directory of Open Access Journals (Sweden)

    C. Rubio

    Full Text Available En este artículo se hace una revisión exhaustiva del zinc, elemento metálico esencial para el funcionamiento del organismo. Repasamos y reflejamos aspectos relacionados con la farmacocinética, con las fuentes dietéticas más importantes, así como las IDR (Ingestas Dietéticas Recomendadas del mismo. También se hace mención a los signos y síntomas relacionados tanto con una ingesta deficiente, como con posibles efectos tóxicos, derivados de ingestas excesivas.

  2. Danxia Zinc Smelter started construction

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>Zinc smelting project of Danxia Smelting Plant has a total investment of about RMB 4 billion, which is designed by Changsha Engineering & Research Institute of Nonferrous Metallurgy and planned to be implemented in three stages. The first stage 100,000 tons of electrolytic zinc improvement work is planned to be completed by the end of 2008. The second and third stages

  3. Neural Network Applications

    NARCIS (Netherlands)

    Vonk, E.; Jain, L.C.; Veelenturf, L.P.J.

    1995-01-01

    Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering areas

  4. 21 CFR 73.1991 - Zinc oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1991 Zinc oxide. (a) Identity. (1) The color additive zinc...). It is principally composed of Zn. (2) Color additive mixtures for drug use made with zinc oxide...

  5. Zinc-bromine battery development

    Science.gov (United States)

    Richards, Lew; Vanschalwijk, Walter; Albert, George; Tarjanyi, Mike; Leo, Anthony; Lott, Stephen

    1990-05-01

    This report describes development activities on the zinc-bromine battery system conducted by Energy Research Corporation (ERC). The project was a cost-shared program supported by the U.S. Department of Energy and managed through Sandia. The project began in September 1985 and ran through January 1990. The zinc-bromine battery has been identified as a promising alternative to conventional energy storage options for many applications. The low cost of the battery reactants and the potential for long life make the system an attractive candidate for bulk energy storage applications, such as utility load leveling. The battery stores energy by the electrolysis of an aqueous zinc bromide salt to zinc metal and dissolved bromine. Zinc is plated as a layer on the electrode surface while bromine is dissolved in the electrolyte and carried out of the stack. The bromine is then extracted from the electrolyte with an organic complexing agent in the positive electrolyte storage tank. On discharge the zinc and bromine are consumed, regenerating the zinc bromide salt.

  6. Cytotoxicity of zinc in vitro.

    Science.gov (United States)

    Borovanský, J; Riley, P A

    1989-01-01

    The effect of zinc ions on B16 mouse melanoma lines, HeLa cells and I-221 epithelial cells was investigated in vitro in order to ascertain whether sensitivity to Zn2+ is a general feature of cells in vitro and in an attempt to elucidate the mechanism(s) of zinc cytotoxicity. The proliferation of B16, HeLa and I-221 cell lines was inhibited by 1.25 x 10(-4), 1.50 x 10(-4) and 1.50 x 10(-4) mol/l Zn2+, respectively. The free radical scavengers, methimazole and ethanol, did not suppress the toxicity of Zn2+, neither did superoxide dismutase or catalase. The addition of the chelating agent EDTA reduced the zinc cytotoxicity. It was possible to suppress the cytotoxicity of zinc by increasing the concentration of either Fe2+ or Ca2+ but not Mg2+, which suggests that a prerequisite for the toxic action of zinc is entry into cells using channels that are shared with iron or calcium. This view was supported by experiments in which transferrin intensified the cytotoxic action of zinc in serum-free medium. Another agent facilitating zinc transport, prostaglandin E2, inhibited the proliferation of the B16 melanoma cell line. There were no conspicuous differences in zinc toxicity to pigmented and unpigmented cells. The toxic effect of zinc in the cell systems studied exceeded that of iron, copper, manganese and cobalt in the same concentration range. In vitro, Zn2+ should be regarded as a dangerous cation.

  7. Zinc and cadmium monosalicylates

    Energy Technology Data Exchange (ETDEWEB)

    Kharitonov, Yu.Ya.; Tujebakhova, Z.K. (Moskovskij Khimiko-Tekhnologicheskij Inst. (USSR))

    1984-06-01

    Zinc and cadmium monosalicylates of the composition MSal, where M-Zn or Cd, Sal - twice deprotonated residue of salicylic acid O-HOC/sub 6/H/sub 4/COOH (H/sub 2/Sal), are singled out and characterized. When studying thermograms, thermogravigrams, IR absorption spectra, roentgenograms of cadmium salicylate compounds (Cd(OC/sub 6/H/sub 4/COO) and products of their thermal transformations, the processes of thermal decomposition of the compounds have been characterized. The process of cadmium monosalicylate decomposition takes place in one stage. Complete loss of salicylate acido group occurs in the range of 320-460 deg. At this decomposition stage cadmium oxide is formed. A supposition is made that cadmium complex has tetrahedral configuration, at that, each salicylate group plays the role of tetradentate-bridge ligand. The compound evidently has a polymer structure.

  8. Zinc Oxide Nanoparticle Photodetector

    Directory of Open Access Journals (Sweden)

    Sheng-Po Chang

    2012-01-01

    Full Text Available A zinc oxide (ZnO nanoparticle photodetector was fabricated using a simple method. Under a 5 V applied bias, its dark current and photocurrent were 1.98×10-8 and 9.42×10-7 A, respectively. In other words, a photocurrent-to-dark-current contrast ratio of 48 was obtained. Under incident light at a wavelength of 375 nm and a 5 V applied bias, the detector’s measured responsivity was 3.75 A/W. The transient time constants measured during the turn-ON and turn-OFF states were τON=204 s and τOFF=486 s, respectively.

  9. Use of serum zinc concentration as an indicator of population zinc status.

    Science.gov (United States)

    Hess, Sonja Y; Peerson, Janet M; King, Janet C; Brown, Kenneth H

    2007-09-01

    Assessing the prevalence and severity of zinc deficiency in populations is critical to determine the need for and appropriate targeting of zinc intervention programs and to assess their effectiveness for improving the health and well-being of high-risk populations. However, there is very little information on the zinc status of populations worldwide due to the lack of consensus on appropriate biochemical indicators of zinc status. The objective of this review was to evaluate the use of serum zinc concentration as an indicator of population zinc status. We have reviewed the response of serum zinc concentration to dietary zinc restriction and zinc supplementation. In addition, we completed pooled analyses of nine zinc intervention trials in young children to assess the relations between serum zinc concentration of individuals before treatment and their responses to zinc supplementation. Also, in updated combined analyses of previously published data, we investigated the relation between the mean initial serum zinc concentration of a study population and their mean growth responses to zinc supplementation in randomized intervention trials among children. The results from depletion/repletion studies indicate that serum zinc concentrations respond appreciably to severe dietary zinc restriction, although there is considerable interindividual variation in these responses. There is also clear evidence that both individual and population mean serum zinc concentrations increase consistently during zinc supplementation, regardless of the initial level of serum zinc concentration. By contrast, an individual's serum zinc concentration does not reliably predict that person's response to zinc supplementation. Serum zinc concentration can be considered a useful biomarker of a population's risk of zinc deficiency and response to zinc interventions, although it may not be a reliable indicator of individual zinc status.

  10. Zinc tolerance and zinc removal ability of living and dried biomass of Desmodesmus communis.

    Science.gov (United States)

    Novák, Zoltán; Jánószky, Mihály; B-Béres, Viktória; Nagy, Sándor Alex; Bácsi, István

    2014-12-01

    Effects of zinc on growth, cell morphology, oxidative stress, and zinc removal ability of the common phytoplankton species Desmodesmus communis were investigated at a concentration range of 0.25-160 mg L(-1) zinc. Cell densities and chlorophyll content decreased in treated cultures, changes in coenobia morphology and elevated lipid peroxidation levels appeared above 2.5 mg L(-1) zinc. The most effective zinc removal was observed at 5 mg L(-1) zinc concentration, while maximal amount of removed zinc appeared in 15 mg L(-1) zinc treated culture. Removed zinc is mainly bound on the cell surface. Dead biomass adsorbed more zinc than living biomass relative to unit of dry mass, but living biomass was more effective, relative to initial zinc content. This study comprehensively examines the zinc tolerance and removal ability of D. communis and demonstrates, in comparison with published literature, that these characteristics of different isolates of the same species can vary within a wide range.

  11. Zinc toxicology following particulate inhalation

    Directory of Open Access Journals (Sweden)

    Cooper Ross

    2008-01-01

    Full Text Available The current mini-review describes the toxic effects of zinc inhalation principally in the workplace and associated complications with breathing and respiration. The International Classification of Functioning, Disability and Health Criteria were used to specifically select articles. Most of the commercial production of zinc involves the galvanizing of iron and the manufacture of brass. The recommended daily allowance for adults is 15 mg zinc/day. Metal fume fever associated with inhalation of fumes of ZnO is characterized by fatigue, chills, fever, myalgias, cough, dyspnea, leukocytosis, thirst, metallic taste and salivation. ZnCl 2 inhalation results in edema in the alveolar surface and the protein therein the lavage fluid is elevated. Particular pathological changes associated with zinc intoxication include: pale mucous membranes; jaundice; numerous Heinz bodies; and marked anemia. Adequate ambient air monitors for permissible exposure limits, excellent ventilation and extraction systems, and approved respirators are all important in providing adequate protection.

  12. Neural Induction, Neural Fate Stabilization, and Neural Stem Cells

    Directory of Open Access Journals (Sweden)

    Sally A. Moody

    2002-01-01

    Full Text Available The promise of stem cell therapy is expected to greatly benefit the treatment of neurodegenerative diseases. An underlying biological reason for the progressive functional losses associated with these diseases is the extremely low natural rate of self-repair in the nervous system. Although the mature CNS harbors a limited number of self-renewing stem cells, these make a significant contribution to only a few areas of brain. Therefore, it is particularly important to understand how to manipulate embryonic stem cells and adult neural stem cells so their descendants can repopulate and functionally repair damaged brain regions. A large knowledge base has been gathered about the normal processes of neural development. The time has come for this information to be applied to the problems of obtaining sufficient, neurally committed stem cells for clinical use. In this article we review the process of neural induction, by which the embryonic ectodermal cells are directed to form the neural plate, and the process of neural�fate stabilization, by which neural plate cells expand in number and consolidate their neural fate. We will present the current knowledge of the transcription factors and signaling molecules that are known to be involved in these processes. We will discuss how these factors may be relevant to manipulating embryonic stem cells to express a neural fate and to produce large numbers of neurally committed, yet undifferentiated, stem cells for transplantation therapies.

  13. Prevalence of Zinc Deficiency by “ Zinc Taste Test” in Pre School Children in Yazd.

    Directory of Open Access Journals (Sweden)

    Gh Maleki

    2004-10-01

    Full Text Available Introduction: Zinc deficiency is a health problem in many communities, especially among children because of growth spurt. Zinc deficiency can cause;growth limitation, delay in sexuel maturity, behavior disorders and abnormalities of immune system,susceptibility to respiratory and gasterointestinal infections and impairment of taste and smell perception. Material and Method: One of the methods of assessment the zinc defeciency is “ Zinc taste test” using zinc sulfate solution 0.1% , this test performed used to assess the zinc deficiency among preshool childeren in Yazd. The results were evaluated with measurments of weight,height and demographic data. 400 preschool children were selected by multi stage random sampling.Having good taste perception of zinc sulfate 0.1% was used as impaired taste test ( zinc deficiency and having bad taste perception as normal zinc level. Results: Regarding to zinc taste test 73.9% of study group had zinc deficiency (77.6%femal, 69.7% male There were no significant relation between zinc deficiency and measurment of weight and height,but there was higher prevalence of zinc deficiency in children who were below the 5th percentile in height and weight by age. Conclusion: 70% of preschool children in yazd had zinc deficiency assessed by “ zinc taste test”,31% of adolecents in Tehran have had zinc deficiency based on plasma , erythrocyte and hairindex. There is no significant relation between zinc deficiency and antropometric and demographic data, in this study and the study that had been done on adolescents in Tehran.Considering the prevalnce of zinc deficiency with “ Zinc taste test” ;it seems more accurate studies need to be done like zinc measurment in WBC,RBC and Platelets and zinc taste test at the same time,if correlation coefficients between zinc taste test and other tests were very strong , we can used zinc tase test in the different age for assessment of zinc body.

  14. [Role of zinc in type 2 diabetes].

    Science.gov (United States)

    Tamaki, Motoyuki; Fujitani, Yoshio

    2014-01-01

    Pancreatic β cells contain the highest amount of zinc among cells within the human body, and hence, the relationship between zinc and diabetes has been of great interest. To date, many studies of zinc and diabetes have been reported, including studies demonstrating that diabetic patients and mice have a decreased amount of zinc in the pancreas. Zinc may counteract the deleterious effects of oxidative stress, which contributes to reduced insulin resistance, and may also protect pancreatic β cells from glucolipotoxicity. Recently, we have shown that SLC30A8/zinc transporter 8, which is a transporter expressed on the surface of insulin granules, plays a key role in zinc transport into insulin granules and in the regulation of hepatic insulin clearance. Here, we review the role of zinc in whole-body maintenance and the latest information on the relationship between zinc and diabetes.

  15. Combined copper/zinc attachment to prion protein

    Science.gov (United States)

    Hodak, Miroslav; Bernholc, Jerry

    2013-03-01

    Misfolding of prion protein (PrP) is responsible for diseases such as ``mad-cow disease'' in cattle and Creutzfeldt-Jacob in humans. Extensive experimental investigation has established that this protein strongly interacts with copper ions, and this ability has been linked to its still unknown function. Attachment of other metal ions (zinc, iron, manganese) have been demonstrated as well, but none of them could outcompete copper. Recent finding, however, indicates that at intermediate concentrations both copper and zinc ions can attach to the PrP at the octarepeat region, which contains high affinity metal binding sites. Based on this evidence, we have performed density functional theory simulations to investigate the combined Cu/Zn attachment. We consider all previously reported binding modes of copper at the octarepeat region and examine a possibility simultaneous Cu/Zn attachment. We find that this can indeed occur for only one of the known binding sites, when copper changes its coordination mode to allow for attachment of zinc ion. The implications of the simultaneous attachment on neural function remain to be explored.

  16. Paired-pulse facilitation achieved in protonic/electronic hybrid indium gallium zinc oxide synaptic transistors

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Li Qiang, E-mail: guoliqiang@ujs.edu.cn; Ding, Jian Ning; Huang, Yu Kai [Micro/Nano Science & Technology Center, Jiangsu University, Zhenjiang, 212013 (China); Zhu, Li Qiang, E-mail: lqzhu@nimte.ac.cn [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2015-08-15

    Neuromorphic devices with paired pulse facilitation emulating that of biological synapses are the key to develop artificial neural networks. Here, phosphorus-doped nanogranular SiO{sub 2} electrolyte is used as gate dielectric for protonic/electronic hybrid indium gallium zinc oxide (IGZO) synaptic transistor. In such synaptic transistors, protons within the SiO{sub 2} electrolyte are deemed as neurotransmitters of biological synapses. Paired-pulse facilitation (PPF) behaviors for the analogous information were mimicked. The temperature dependent PPF behaviors were also investigated systematically. The results indicate that the protonic/electronic hybrid IGZO synaptic transistors would be promising candidates for inorganic synapses in artificial neural network applications.

  17. Influence of DNA-methylation on zinc homeostasis in myeloid cells: Regulation of zinc transporters and zinc binding proteins.

    Science.gov (United States)

    Kessels, Jana Elena; Wessels, Inga; Haase, Hajo; Rink, Lothar; Uciechowski, Peter

    2016-09-01

    The distribution of intracellular zinc, predominantly regulated through zinc transporters and zinc binding proteins, is required to support an efficient immune response. Epigenetic mechanisms such as DNA methylation are involved in the expression of these genes. In demethylation experiments using 5-Aza-2'-deoxycytidine (AZA) increased intracellular (after 24 and 48h) and total cellular zinc levels (after 48h) were observed in the myeloid cell line HL-60. To uncover the mechanisms that cause the disturbed zinc homeostasis after DNA demethylation, the expression of human zinc transporters and zinc binding proteins were investigated. Real time PCR analyses of 14 ZIP (solute-linked carrier (SLC) SLC39A; Zrt/IRT-like protein), and 9 ZnT (SLC30A) zinc transporters revealed significantly enhanced mRNA expression of the zinc importer ZIP1 after AZA treatment. Because ZIP1 protein was also enhanced after AZA treatment, ZIP1 up-regulation might be the mediator of enhanced intracellular zinc levels. The mRNA expression of ZIP14 was decreased, whereas zinc exporter ZnT3 mRNA was also significantly increased; which might be a cellular reaction to compensate elevated zinc levels. An enhanced but not significant chromatin accessibility of ZIP1 promoter region I was detected by chromatin accessibility by real-time PCR (CHART) assays after demethylation. Additionally, DNA demethylation resulted in increased mRNA accumulation of zinc binding proteins metallothionein (MT) and S100A8/S100A9 after 48h. MT mRNA was significantly enhanced after 24h of AZA treatment also suggesting a reaction of the cell to restore zinc homeostasis. These data indicate that DNA methylation is an important epigenetic mechanism affecting zinc binding proteins and transporters, and, therefore, regulating zinc homeostasis in myeloid cells.

  18. High dose zinc supplementation induces hippocampal zinc deficiency and memory impairment with inhibition of BDNF signaling.

    Directory of Open Access Journals (Sweden)

    Yang Yang

    Full Text Available Zinc ions highly concentrate in hippocampus and play a key role in modulating spatial learning and memory. At a time when dietary fortification and supplementation of zinc have increased the zinc consuming level especially in the youth, the toxicity of zinc overdose on brain function was underestimated. In the present study, weaning ICR mice were given water supplemented with 15 ppm Zn (low dose, 60 ppm Zn (high dose or normal lab water for 3 months, the behavior and brain zinc homeostasis were tested. Mice fed high dose of zinc showed hippocampus-dependent memory impairment. Unexpectedly, zinc deficiency, but not zinc overload was observed in hippocampus, especially in the mossy fiber-CA3 pyramid synapse. The expression levels of learning and memory related receptors and synaptic proteins such as NMDA-NR2A, NR2B, AMPA-GluR1, PSD-93 and PSD-95 were significantly decreased in hippocampus, with significant loss of dendritic spines. In keeping with these findings, high dose intake of zinc resulted in decreased hippocampal BDNF level and TrkB neurotrophic signaling. At last, increasing the brain zinc level directly by brain zinc injection induced BDNF expression, which was reversed by zinc chelating in vivo. These results indicate that zinc plays an important role in hippocampus-dependent learning and memory and BDNF expression, high dose supplementation of zinc induces specific zinc deficiency in hippocampus, which further impair learning and memory due to decreased availability of synaptic zinc and BDNF deficit.

  19. High dose zinc supplementation induces hippocampal zinc deficiency and memory impairment with inhibition of BDNF signaling.

    Science.gov (United States)

    Yang, Yang; Jing, Xiao-Peng; Zhang, Shou-Peng; Gu, Run-Xia; Tang, Fang-Xu; Wang, Xiu-Lian; Xiong, Yan; Qiu, Mei; Sun, Xu-Ying; Ke, Dan; Wang, Jian-Zhi; Liu, Rong

    2013-01-01

    Zinc ions highly concentrate in hippocampus and play a key role in modulating spatial learning and memory. At a time when dietary fortification and supplementation of zinc have increased the zinc consuming level especially in the youth, the toxicity of zinc overdose on brain function was underestimated. In the present study, weaning ICR mice were given water supplemented with 15 ppm Zn (low dose), 60 ppm Zn (high dose) or normal lab water for 3 months, the behavior and brain zinc homeostasis were tested. Mice fed high dose of zinc showed hippocampus-dependent memory impairment. Unexpectedly, zinc deficiency, but not zinc overload was observed in hippocampus, especially in the mossy fiber-CA3 pyramid synapse. The expression levels of learning and memory related receptors and synaptic proteins such as NMDA-NR2A, NR2B, AMPA-GluR1, PSD-93 and PSD-95 were significantly decreased in hippocampus, with significant loss of dendritic spines. In keeping with these findings, high dose intake of zinc resulted in decreased hippocampal BDNF level and TrkB neurotrophic signaling. At last, increasing the brain zinc level directly by brain zinc injection induced BDNF expression, which was reversed by zinc chelating in vivo. These results indicate that zinc plays an important role in hippocampus-dependent learning and memory and BDNF expression, high dose supplementation of zinc induces specific zinc deficiency in hippocampus, which further impair learning and memory due to decreased availability of synaptic zinc and BDNF deficit.

  20. Zinc Plating Industry Drives Zinc Consumption by Power Grids, Railways and Highways

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>On the afternoon of June 30, at the Chengdu Lead and Zinc Summit, more than 150 partici-pants voted for the product they felt drives zinc consumption the most. 48% went for zinc plat-ing products, 16% voted for zinc oxide,

  1. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In ...

  2. Morphological neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, G.X.; Sussner, P. [Univ. of Florida, Gainesville, FL (United States)

    1996-12-31

    The theory of artificial neural networks has been successfully applied to a wide variety of pattern recognition problems. In this theory, the first step in computing the next state of a neuron or in performing the next layer neural network computation involves the linear operation of multiplying neural values by their synaptic strengths and adding the results. Thresholding usually follows the linear operation in order to provide for nonlinearity of the network. In this paper we introduce a novel class of neural networks, called morphological neural networks, in which the operations of multiplication and addition are replaced by addition and maximum (or minimum), respectively. By taking the maximum (or minimum) of sums instead of the sum of products, morphological network computation is nonlinear before thresholding. As a consequence, the properties of morphological neural networks are drastically different than those of traditional neural network models. In this paper we consider some of these differences and provide some particular examples of morphological neural network.

  3. Artificial Neural Networks

    OpenAIRE

    Chung-Ming Kuan

    2006-01-01

    Artificial neural networks (ANNs) constitute a class of flexible nonlinear models designed to mimic biological neural systems. In this entry, we introduce ANN using familiar econometric terminology and provide an overview of ANN modeling approach and its implementation methods.

  4. Zinc Blotting Assay for Detection of Zinc-Binding Prolamin in Barley (Hordeum vulgare) Grain

    DEFF Research Database (Denmark)

    Uddin, Mohammad Nasir; Langkilde, Ane; Vincze, Éva

    2014-01-01

    In plants, zinc is commonly found bound to proteins. In barley (Hordeum vulgare), major storage proteins are alcohol-soluble prolamins known as hordeins, and some of them have the potential to bind or store zinc. 65Zn overlay and blotting techniques have been widely used for detecting zinc......-binding protein. However, to our knowledge so far this zinc blotting assay has never been applied to detect a prolamin fraction in barley grains. A radioactive zinc (65ZnCl2) blotting technique was optimized to detect zinc-binding prolamins, followed by development of an easy-to-follow nonradioactive colorimetric...... zinc blotting method with a zinc-sensing dye, dithizone. Hordeins were extracted from mature barley grain, separated by SDS-PAGE, blotted on a membrane, renatured, overlaid, and probed with zinc; subsequently, zinc-binding specificity of certain proteins was detected either by autoradiography or color...

  5. Neural tissue-spheres

    DEFF Research Database (Denmark)

    Andersen, Rikke K; Johansen, Mathias; Blaabjerg, Morten

    2007-01-01

    By combining new and established protocols we have developed a procedure for isolation and propagation of neural precursor cells from the forebrain subventricular zone (SVZ) of newborn rats. Small tissue blocks of the SVZ were dissected and propagated en bloc as free-floating neural tissue...... content, thus allowing experimental studies of neural precursor cells and their niche...

  6. READING A NEURAL CODE

    NARCIS (Netherlands)

    BIALEK, W; RIEKE, F; VANSTEVENINCK, RRD; WARLAND, D

    1991-01-01

    Traditional approaches to neural coding characterize the encoding of known stimuli in average neural responses. Organisms face nearly the opposite task - extracting information about an unknown time-dependent stimulus from short segments of a spike train. Here the neural code was characterized from

  7. Generalized classifier neural network.

    Science.gov (United States)

    Ozyildirim, Buse Melis; Avci, Mutlu

    2013-03-01

    In this work a new radial basis function based classification neural network named as generalized classifier neural network, is proposed. The proposed generalized classifier neural network has five layers, unlike other radial basis function based neural networks such as generalized regression neural network and probabilistic neural network. They are input, pattern, summation, normalization and output layers. In addition to topological difference, the proposed neural network has gradient descent based optimization of smoothing parameter approach and diverge effect term added calculation improvements. Diverge effect term is an improvement on summation layer calculation to supply additional separation ability and flexibility. Performance of generalized classifier neural network is compared with that of the probabilistic neural network, multilayer perceptron algorithm and radial basis function neural network on 9 different data sets and with that of generalized regression neural network on 3 different data sets include only two classes in MATLAB environment. Better classification performance up to %89 is observed. Improved classification performances proved the effectivity of the proposed neural network.

  8. Zinc metalloproteins as medicinal targets.

    Science.gov (United States)

    Anzellotti, A I; Farrell, N P

    2008-08-01

    Zinc bioinorganic chemistry has emphasized the role of the metal ion on the structure and function of the protein. There is, more recently, an increasing appreciation of the role of zinc proteins in a variety of human diseases. This critical review, aimed at both bioinorganic and medicinal chemists, shows how apparently widely-diverging diseases share the common mechanistic approaches of targeting the essential function of the metal ion to inhibit activity. Protein structure and function is briefly summarized in the context of its clinical relevance. The status of current and potential inhibitors is discussed along with the prospects for future developments (162 references).

  9. 21 CFR 558.78 - Bacitracin zinc.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Bacitracin zinc. 558.78 Section 558.78 Food and... in Animal Feeds § 558.78 Bacitracin zinc. (a) Specifications. Type A medicated articles containing bacitracin zinc equivalent to 10, 25, 40, or 50 grams per pound bacitracin. (b) Approvals. See No. 046573...

  10. 21 CFR 582.5991 - Zinc oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Zinc oxide. 582.5991 Section 582.5991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use. This substance is...

  11. 21 CFR 182.8991 - Zinc oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Zinc oxide. 182.8991 Section 182.8991 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use. This substance is generally recognized as safe when used...

  12. 21 CFR 73.2991 - Zinc oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Zinc oxide. 73.2991 Section 73.2991 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2991 Zinc oxide. (a) Identity and specifications. The color additive zinc oxide shall conform in identity and specifications to the requirements of §...

  13. Zinc supplementation in children with cystic fibrosis

    Science.gov (United States)

    Cystic fibrosis (CF) leads to malabsorption of macro- and micronutrients. Symptomatic zinc deficiency has been reported in CF but little is known about zinc homeostasis in children with CF. Zinc supplementation (Zn suppl) is increasingly common in children with CF but it is not without theoretcial r...

  14. Effect of resveratrol and zinc on intracellular zinc status in normal human prostate epithelial cells

    Science.gov (United States)

    To evaluate the influence of resveratrol on cellular zinc status, normal human prostate epithelial (NHPrE) cells were treated with 6 levels of resveratrol (0, 0.5, 1, 2.5, 5 and 10 microM) and 4 levels of zinc [0, 4, 16, and 32 microM for zinc-deficient (ZD), zinc-normal (ZN), zinc-adequate (ZA), an...

  15. Neural induction and factors that stabilize a neural fate

    OpenAIRE

    Rogers, Crystal; Moody, Sally A.; Casey, Elena

    2009-01-01

    The neural ectoderm of vertebrates forms when the BMP signaling pathway is suppressed. Herein we review the molecules that directly antagonize extracellular BMP and the signaling pathways that further contribute to reduce BMP activity in the neural ectoderm. Downstream of neural induction, a large number of “neural fate stabilizing” (NFS) transcription factors are expressed in the presumptive neural ectoderm, developing neural tube, and ultimately in neural stem cells. Herein we review what i...

  16. Zinc dyshomeostasis during polymicrobial sepsis in mice involves zinc transporter Zip14 and can be overcome by zinc supplementation.

    Science.gov (United States)

    Wessels, Inga; Cousins, Robert J

    2015-11-01

    Integrity of the immune system is particularly dependent on the availability of zinc. Recent data suggest that zinc is involved in the development of sepsis, a life-threatening systemic inflammation with high death rates, but with limited therapeutic options. Altered cell zinc transport mechanisms could contribute to the inflammatory effects of sepsis. Zip14, a zinc importer induced by proinflammatory stimuli, could influence zinc metabolism during sepsis and serve as a target for therapy. Using cecal ligation-and-puncture (CLP) to model polymicrobial sepsis, we narrowed the function of ZIP14 to regulation of zinc homeostasis in hepatocytes, while hepatic leukocytes were mostly responsible for driving inflammation, as shown by higher expression of IL-1β, TNFα, S100A8, and matrix metalloproteinase-8. Using Zip14 knockout (KO) mice as a novel approach, we found that ablation of Zip14 produced a delay in development of leukocytosis, prevented zinc accumulation in the liver, altered the kinetics of hypozincemia, and drastically increased serum IL-6, TNFα, and IL-10 concentrations following CLP. Hence, this model revealed that the zinc transporter ZIP14 is a component of the pathway for zinc redistribution that contributes to zinc dyshomeostasis during polymicrobial sepsis. In contrast, using the identical CLP model, we found that supplemental dietary zinc reduced the severity of sepsis, as shown by amelioration of cytokines, calprotectins, and blood bacterial loads. We conclude that the zinc transporter ZIP14 influences aspects of the pathophysiology of nonlethal polymicrobial murine sepsis induced by CLP through zinc delivery. The results are promising for the use of zinc and its transporters as targets for future sepsis therapy.

  17. Consciousness and neural plasticity

    DEFF Research Database (Denmark)

    In contemporary consciousness studies the phenomenon of neural plasticity has received little attention despite the fact that neural plasticity is of still increased interest in neuroscience. We will, however, argue that neural plasticity could be of great importance to consciousness studies....... If consciousness is related to neural processes it seems, at least prima facie, that the ability of the neural structures to change should be reflected in a theory of this relationship "Neural plasticity" refers to the fact that the brain can change due to its own activity. The brain is not static but rather...... the relation between consciousness and brain functions. If consciousness is connected to specific brain structures (as a function or in identity) what happens to consciousness when those specific underlying structures change? It is therefore possible that the understanding and theories of neural plasticity can...

  18. Non-Chromate Passivation of Zinc

    DEFF Research Database (Denmark)

    Tang, Peter Torben; Bech-Nielsen, G.

    1993-01-01

    . There is no known environmental or health risk involved using the treatments mentioned above. All components used in the baths are non toxic compared to Cr(VI). Alloy coatings such as zinc/nickel, zinc/cobalt, zinc/tin and all types of pure zinc coating (from cyanide, acidic or alkaline baths) have been treated...... minutes, in any one of the baths, at 60¢XC. Some movement of the submerged samples, or stirring with air-bubbles, should be applied, just as a thorough rinse of the zinc surface immediately before the pas-sivation is extremely important....

  19. Pharmacokinetics of zinc tannate after intratesticular injection.

    Science.gov (United States)

    Migally, N B; Fahim, M S

    1984-01-01

    Forty-eight sexually mature male rats were injected intratesticularly with either 1, 3, or 6 mg zinc tannate (Kastrin) or with saline (as control). Zinc localized only in low concentration in primary spermatocytes and could not be detected in spermatogonia, Sertoli cells, spermatids, or spermatozoa. Forty-eight hours after injection of 1 mg Kastrin, zinc was accumulated in the spermatogonia and primary spermatocytes while, after injection of 3 mg, zinc was preferentially localized in Sertoli cells and spermatids; however, zinc was observed in the spermatids and spermatozoa 48 h after injection with 6 mg, and germ cells lost their identity and were fragmented after 1 week.

  20. Zinc leaching from tire crumb rubber.

    Science.gov (United States)

    Rhodes, Emily P; Ren, Zhiyong; Mays, David C

    2012-12-04

    Because tires contain approximately 1-2% zinc by weight, zinc leaching is an environmental concern associated with civil engineering applications of tire crumb rubber. An assessment of zinc leaching data from 14 studies in the published literature indicates that increasing zinc leaching is associated with lower pH and longer leaching times, but the data display a wide range of zinc concentrations, and do not address the effect of crumb rubber size or the dynamics of zinc leaching during flow through porous crumb rubber. The present study was undertaken to investigate the effect of crumb rubber size using the synthetic precipitation leaching procedure (SPLP), the effect of exposure time using quiescent batch leaching tests, and the dynamics of zinc leaching using column tests. Results indicate that zinc leaching from tire crumb rubber increases with smaller crumb rubber and longer exposure time. Results from SPLP and quiescent batch leaching tests are interpreted with a single-parameter leaching model that predicts a constant rate of zinc leaching up to 96 h. Breakthrough curves from column tests displayed an initial pulse of elevated zinc concentration (~3 mg/L) before settling down to a steady-state value (~0.2 mg/L), and were modeled with the software package HYDRUS-1D. Washing crumb rubber reduces this initial pulse but does not change the steady-state value. No leaching experiment significantly reduced the reservoir of zinc in the crumb rubber.

  1. Zinc-The key to preventing corrosion

    Science.gov (United States)

    Kropschot, S.J.; Doebrich, Jeff L.

    2011-01-01

    Centuries before it was identified as an element, zinc was used to make brass (an alloy of zinc and copper) and for medicinal purposes. Metallic zinc and zinc oxide were produced in India sometime between the 11th and 14th centuries and in China in the 17th century, although the discovery of pure metallic zinc is credited to the German chemist Andreas Marggraf, who isolated the element in 1746. Refined zinc metal is bluish-white when freshly cast; it is hard and brittle at most temperatures and has relatively low melting and boiling points. Zinc alloys readily with other metals and is chemically active. On exposure to air, it develops a thin gray oxide film (patina), which inhibits deeper oxidation (corrosion) of the metal. The metal's resistance to corrosion is an important characteristic in its use.

  2. Zinc Therapy in Dermatology: A Review

    Directory of Open Access Journals (Sweden)

    Mrinal Gupta

    2014-01-01

    Full Text Available Zinc, both in elemental or in its salt forms, has been used as a therapeutic modality for centuries. Topical preparations like zinc oxide, calamine, or zinc pyrithione have been in use as photoprotecting, soothing agents or as active ingredient of antidandruff shampoos. Its use has expanded manifold over the years for a number of dermatological conditions including infections (leishmaniasis, warts, inflammatory dermatoses (acne vulgaris, rosacea, pigmentary disorders (melasma, and neoplasias (basal cell carcinoma. Although the role of oral zinc is well-established in human zinc deficiency syndromes including acrodermatitis enteropathica, it is only in recent years that importance of zinc as a micronutrient essential for infant growth and development has been recognized. The paper reviews various dermatological uses of zinc.

  3. Chaotic diagonal recurrent neural network

    Institute of Scientific and Technical Information of China (English)

    Wang Xing-Yuan; Zhang Yi

    2012-01-01

    We propose a novel neural network based on a diagonal recurrent neural network and chaos,and its structure andlearning algorithm are designed.The multilayer feedforward neural network,diagonal recurrent neural network,and chaotic diagonal recurrent neural network are used to approach the cubic symmetry map.The simulation results show that the approximation capability of the chaotic diagonal recurrent neural network is better than the other two neural networks.

  4. Recovery of zinc from low-grade zinc oxide ores by solvent extraction

    Institute of Scientific and Technical Information of China (English)

    覃文庆; 蓝卓越; 黎维中

    2003-01-01

    The recovery of zinc from low-grade zinc oxide ores with solvent extraction-electrowinning technique was investigated by using D2EHPA as extractant and 260# kerosene as diluent. The results show that it is possible to selectively leach zinc from the ores by heap leaching. The zinc concentration of leach solution in the first leaching cycle is 32.57 g/L, and in the sixteenth cycle the zinc concentration is 8.27g/L after solvent extraction. The leaching solution is subjected to solvent extraction, scrubbing and selective stripping for enrichment of zinc and removal of impurities. The pregnant zinc sulfate solution produced from the stripping cycle is suitable for zinc electrowinning.Extra-pure zinc metal was obtained in the electrowinning test under conventional conditions.

  5. Association between Maternal Zinc Status, Dietary Zinc Intake and Pregnancy Complications: A Systematic Review

    Science.gov (United States)

    Wilson, Rebecca L.; Grieger, Jessica A.; Bianco-Miotto, Tina; Roberts, Claire T.

    2016-01-01

    Adequate zinc stores in the body are extremely important during periods of accelerated growth. However, zinc deficiency is common in developing countries and low maternal circulating zinc concentrations have previously been associated with pregnancy complications. We reviewed current literature assessing circulating zinc and dietary zinc intake during pregnancy and the associations with preeclampsia (PE); spontaneous preterm birth (sPTB); low birthweight (LBW); and gestational diabetes (GDM). Searches of MEDLINE; CINAHL and Scopus databases identified 639 articles and 64 studies were reviewed. In 10 out of 16 studies a difference was reported with respect to circulating zinc between women who gave birth to a LBW infant (≤2500 g) and those who gave birth to an infant of adequate weight (>2500 g), particularly in populations where inadequate zinc intake is prevalent. In 16 of our 33 studies an association was found between hypertensive disorders of pregnancy and circulating zinc; particularly in women with severe PE (blood pressure ≥160/110 mmHg). No association between maternal zinc status and sPTB or GDM was seen; however; direct comparisons between the studies was difficult. Furthermore; only a small number of studies were based on women from populations where there is a high risk of zinc deficiency. Therefore; the link between maternal zinc status and pregnancy success in these populations cannot be established. Future studies should focus on those vulnerable to zinc deficiency and include dietary zinc intake as a measure of zinc status. PMID:27754451

  6. Association between Maternal Zinc Status, Dietary Zinc Intake and Pregnancy Complications: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Rebecca L. Wilson

    2016-10-01

    Full Text Available Adequate zinc stores in the body are extremely important during periods of accelerated growth. However, zinc deficiency is common in developing countries and low maternal circulating zinc concentrations have previously been associated with pregnancy complications. We reviewed current literature assessing circulating zinc and dietary zinc intake during pregnancy and the associations with preeclampsia (PE; spontaneous preterm birth (sPTB; low birthweight (LBW; and gestational diabetes (GDM. Searches of MEDLINE; CINAHL and Scopus databases identified 639 articles and 64 studies were reviewed. In 10 out of 16 studies a difference was reported with respect to circulating zinc between women who gave birth to a LBW infant (≤2500 g and those who gave birth to an infant of adequate weight (>2500 g, particularly in populations where inadequate zinc intake is prevalent. In 16 of our 33 studies an association was found between hypertensive disorders of pregnancy and circulating zinc; particularly in women with severe PE (blood pressure ≥160/110 mmHg. No association between maternal zinc status and sPTB or GDM was seen; however; direct comparisons between the studies was difficult. Furthermore; only a small number of studies were based on women from populations where there is a high risk of zinc deficiency. Therefore; the link between maternal zinc status and pregnancy success in these populations cannot be established. Future studies should focus on those vulnerable to zinc deficiency and include dietary zinc intake as a measure of zinc status.

  7. The biological inorganic chemistry of zinc ions.

    Science.gov (United States)

    Krężel, Artur; Maret, Wolfgang

    2016-12-01

    The solution and complexation chemistry of zinc ions is the basis for zinc biology. In living organisms, zinc is redox-inert and has only one valence state: Zn(II). Its coordination environment in proteins is limited by oxygen, nitrogen, and sulfur donors from the side chains of a few amino acids. In an estimated 10% of all human proteins, zinc has a catalytic or structural function and remains bound during the lifetime of the protein. However, in other proteins zinc ions bind reversibly with dissociation and association rates commensurate with the requirements in regulation, transport, transfer, sensing, signalling, and storage. In contrast to the extensive knowledge about zinc proteins, the coordination chemistry of the "mobile" zinc ions in these processes, i.e. when not bound to proteins, is virtually unexplored and the mechanisms of ligand exchange are poorly understood. Knowledge of the biological inorganic chemistry of zinc ions is essential for understanding its cellular biology and for designing complexes that deliver zinc to proteins and chelating agents that remove zinc from proteins, for detecting zinc ion species by qualitative and quantitative analysis, and for proper planning and execution of experiments involving zinc ions and nanoparticles such as zinc oxide (ZnO). In most investigations, reference is made to zinc or Zn(2+) without full appreciation of how biological zinc ions are buffered and how the d-block cation Zn(2+) differs from s-block cations such as Ca(2+) with regard to significantly higher affinity for ligands, preference for the donor atoms of ligands, and coordination dynamics. Zinc needs to be tightly controlled. The interaction with low molecular weight ligands such as water and inorganic and organic anions is highly relevant to its biology but in contrast to its coordination in proteins has not been discussed in the biochemical literature. From the discussion in this article, it is becoming evident that zinc ion speciation is

  8. Influence of phytase, EDTA, and polyphenols on zinc absorption in adults from porridges fortified with zinc sulfate or zinc oxide.

    Science.gov (United States)

    Brnić, Marica; Wegmüller, Rita; Zeder, Christophe; Senti, Gabriela; Hurrell, Richard F

    2014-09-01

    Fortification of cereal staples with zinc is recommended to combat zinc deficiency. To optimize zinc absorption, strategies are needed to overcome the inhibitory effect of phytic acid (PA) and perhaps polyphenols. Five zinc absorption studies were conducted in young adults consuming maize or sorghum porridges fortified with 2 mg zinc as zinc sulfate (ZnSO4) or zinc oxide (ZnO) and containing combinations of PA or polyphenols as potential inhibitors and EDTA and phytase as potential enhancers. Fractional absorption of zinc (FAZ) was measured by using the double isotopic tracer ratio method. Adding phytase to the maize porridge immediately before consumption or using phytase for dephytinization during meal preparation both increased FAZ by >80% (both P zinc molar ratio of 1:1 increased FAZ from maize porridge fortified with ZnSO4 by 30% (P = 0.01) but had no influence at higher EDTA ratios or on absorption from ZnO. FAZ was slightly higher from ZnSO4 than from ZnO (P = 0.02). Sorghum polyphenols had no effect on FAZ from dephytinized sorghum porridges but decreased FAZ by 20% from PA-rich sorghum porridges (P zinc absorption from zinc-fortified cereals, EDTA at a 1:1 molar ratio modestly enhanced zinc absorption from ZnSO4-fortified cereals but not ZnO-fortified cereals, and sorghum polyphenols inhibited zinc absorption in the presence, but not absence, of PA. This trial was registered at clinicaltrials.gov as NCT01210794.

  9. Evolvable Neural Software System

    Science.gov (United States)

    Curtis, Steven A.

    2009-01-01

    The Evolvable Neural Software System (ENSS) is composed of sets of Neural Basis Functions (NBFs), which can be totally autonomously created and removed according to the changing needs and requirements of the software system. The resulting structure is both hierarchical and self-similar in that a given set of NBFs may have a ruler NBF, which in turn communicates with other sets of NBFs. These sets of NBFs may function as nodes to a ruler node, which are also NBF constructs. In this manner, the synthetic neural system can exhibit the complexity, three-dimensional connectivity, and adaptability of biological neural systems. An added advantage of ENSS over a natural neural system is its ability to modify its core genetic code in response to environmental changes as reflected in needs and requirements. The neural system is fully adaptive and evolvable and is trainable before release. It continues to rewire itself while on the job. The NBF is a unique, bilevel intelligence neural system composed of a higher-level heuristic neural system (HNS) and a lower-level, autonomic neural system (ANS). Taken together, the HNS and the ANS give each NBF the complete capabilities of a biological neural system to match sensory inputs to actions. Another feature of the NBF is the Evolvable Neural Interface (ENI), which links the HNS and ANS. The ENI solves the interface problem between these two systems by actively adapting and evolving from a primitive initial state (a Neural Thread) to a complicated, operational ENI and successfully adapting to a training sequence of sensory input. This simulates the adaptation of a biological neural system in a developmental phase. Within the greater multi-NBF and multi-node ENSS, self-similar ENI s provide the basis for inter-NBF and inter-node connectivity.

  10. Investigation of the GPR39 zinc receptor following inhibition of monoaminergic neurotransmission and potentialization of glutamatergic neurotransmission

    DEFF Research Database (Denmark)

    Młyniec, Katarzyna; Gaweł, Magdalena; Librowski, Tadeusz;

    2015-01-01

    . There were no changes in serum zinc levels. Additionally, we investigated tryptophan, tyrosine and glutamate concentrations in the hippocampus and frontal cortex of GPR39 knockout (GPR39 KO) mice. Liquid chromatography-mass spectrometry (LC-MS) showed a significant decrease in tryptophan and tyrosine......Zinc can regulate neural function in the brain via the GPR39 receptor. In the present study we investigated whether inhibition of serotonin, noradrenaline and dopamine synthesis and potentialization of glutamate, via administration of p-chlorophenylalanine (pCPA), α-methyl-p-tyrosine (αMT) and N...

  11. El zinc: oligoelemento esencial Zinc: an essential oligoelement

    Directory of Open Access Journals (Sweden)

    C. Rubio

    2007-02-01

    Full Text Available En este artículo se hace una revisión exhaustiva del zinc, elemento metálico esencial para el funcionamiento del organismo. Repasamos y reflejamos aspectos relacionados con la farmacocinética, con las fuentes dietéticas más importantes, así como las IDR (Ingestas Dietéticas Recomendadas del mismo. También se hace mención a los signos y síntomas relacionados tanto con una ingesta deficiente, como con posibles efectos tóxicos, derivados de ingestas excesivas.This article comprehensively reviews zinc, the metallic element essential for body functioning. We review and highlight issues related to pharmacokinetics, the most important dietary sources, as well as its RDIs (Recommended Dietary Intakes. We also focus on signs and symptoms related with both a deficient intake and possible toxic effects derived from excessive intakes.

  12. Intracellular zinc distribution in mitochondria, ER and the Golgi apparatus.

    Science.gov (United States)

    Lu, Qiping; Haragopal, Hariprakash; Slepchenko, Kira G; Stork, Christian; Li, Yang V

    2016-01-01

    Zinc (Zn(2+)) is required for numerous cellular functions. As such, the homeostasis and distribution of intracellular zinc can influence cellular metabolism and signaling. However, the exact distribution of free zinc within live cells remains elusive. Previously we showed the release of zinc from thapsigargin/IP3-sensitive endoplasmic reticulum (ER) storage in cortical neurons. In the present study, we investigated if other cellular organelles also contain free chelatable zinc and function as organelle storage for zinc. To identify free zinc within the organelles, live cells were co-stained with Zinpyr-1, a zinc fluorescent dye, and organelle-specific fluorescent dyes (MitoFluor Red 589: mitochondria; ER Tracker Red: endoplasmic reticulum; BODIPY TR ceramide: Golgi apparatus; Syto Red 64: nucleus). We examined organelles that represent potential storing sites for intracellular zinc. We showed that zinc fluorescence staining was co-localized with MitoFluor Red 589, ER Tracker Red, and BODIPY TR ceramide respectively, suggesting the presence of free zinc in mitochondria, endoplasmic reticulum, and the Golgi apparatus. On the other hand, cytosol and nucleus had nearly no detectable zinc fluorescence. It is known that nucleus contains high amount of zinc binding proteins that have high zinc binding affinity. The absence of zinc fluorescence suggests that there is little free zinc in these two regions. It also indicates that the zinc fluorescence detected in mitochondria, ER and Golgi apparatus represents free chelatable zinc. Taken together, our results support that these organelles are potential zinc storing organelles during cellular zinc homeostasis.

  13. The Current Trend of China’s Zinc Consumption

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> According to estimations of zinc consumptionby China’s major zinc consumption industries,the growth rate of China’s actual zinc con-sumption in the period 1998-2002 was 10.2percent.Of China’s total zinc consumption inyear 2002,galvanizing zinc made 36 percent,

  14. Zinc stannate nanostructures: hydrothermal synthesis

    Directory of Open Access Journals (Sweden)

    Sunandan Baruah and Joydeep Dutta

    2011-01-01

    Full Text Available Nanostructured binary semiconducting metal oxides have received much attention in the last decade owing to their unique properties rendering them suitable for a wide range of applications. In the quest to further improve the physical and chemical properties, an interest in ternary complex oxides has become noticeable in recent times. Zinc stannate or zinc tin oxide (ZTO is a class of ternary oxides that are known for their stable properties under extreme conditions, higher electron mobility compared to its binary counterparts and other interesting optical properties. The material is thus ideal for applications from solar cells and sensors to photocatalysts. Among the different methods of synthesizing ZTO nanostructures, the hydrothermal method is an attractive green process that is carried out at low temperatures. In this review, we summarize the conditions leading to the growth of different ZTO nanostructures using the hydrothermal method and delve into a few of its applications reported in the literature.

  15. Morphology study of electrodeposited zinc from zinc sulfate solutions as anode for zinc-air and zinc-carbon batteries

    Directory of Open Access Journals (Sweden)

    Nurhaswani Alias

    2015-01-01

    Full Text Available The morphology of Zinc (Zn deposits was investigated as anode for aqueous batteries. The Zn was deposited from zinc sulfate solution in direct current conditions on a copper surface at different current densities. The morphology characterization of Zn deposits was performed via field emission scanning electron microscopy. The Zn deposits transformed from a dense and compact structure to dendritic form with increasing current density. The electrodeposition of Zn with a current density of 0.02 A cm−2 exhibited good morphology with a high charge efficiency that reached up to 95.2%. The Zn deposits were applied as the anode in zinc–air and zinc–carbon batteries, which gave specific discharge capacities of 460 and 300 mA h g−1, respectively.

  16. A neural flow estimator

    DEFF Research Database (Denmark)

    Jørgensen, Ivan Harald Holger; Bogason, Gudmundur; Bruun, Erik

    1995-01-01

    This paper proposes a new way to estimate the flow in a micromechanical flow channel. A neural network is used to estimate the delay of random temperature fluctuations induced in a fluid. The design and implementation of a hardware efficient neural flow estimator is described. The system...... is implemented using switched-current technique and is capable of estimating flow in the μl/s range. The neural estimator is built around a multiplierless neural network, containing 96 synaptic weights which are updated using the LMS1-algorithm. An experimental chip has been designed that operates at 5 V...

  17. Neural Systems Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — As part of the Electrical and Computer Engineering Department and The Institute for System Research, the Neural Systems Laboratory studies the functionality of the...

  18. Production of nano zinc, zinc sulphide and nanocomplex of magnetite zinc oxide by Brevundimonas diminuta and Pseudomonas stutzeri.

    Science.gov (United States)

    Mirhendi, Mansoureh; Emtiazi, Giti; Roghanian, Rasoul

    2013-12-01

    ZnO (Zincite) nanoparticle has many industrial applications and is mostly produced by chemical reactions, usually prepared by decomposition of zinc acetate or hot-injection and heating-up method. Synthesis of semi-conductor nanoparticles such as ZnS (Sphalerite) by ultrasonic was previously reported. In this work, high-zinc tolerant bacteria were isolated and used for nano zinc production. Among all isolated microorganisms, a gram negative bacterium which was identified as Brevundimonas diminuta could construct nano magnetite zinc oxide on bacterial surface with 22 nm in size and nano zinc with 48.29 nm in size. A piece of zinc metal was immersed in medium containing of pure culture of B. diminuta. Subsequently, a yellow-white biofilm was formed which was collected from the surface of zinc. It was dried at room temperature. The isolated biofilm was analysed by X-ray diffractometer. Interestingly, the yield of these particles was higher in the light, with pH 7 at 23°C. To the best of the authors knowledge, this is the first report about the production of nano zinc metal and nano zinc oxide that are stable and have anti-bacterial activities with magnetite property. Also ZnS (sized 12 nm) produced by Pseudomonas stutzeri, was studied by photoluminescence and fluorescent microscope.

  19. Recovery of Zinc from Zinc Ash and Flue Dusts by Hydrometallurgical Processing

    Science.gov (United States)

    Thorsen, G.; Grislingås, A.; Steintveit, G.

    1981-01-01

    A process has been developed for recovering zinc and other metal values from chloride-containing solid zinc waste materials such as zinc ash from galvanizing baths, and flue dusts from zinc smelting and Waelz processes. The waste is leached with a liquid organic phase containing a cation exchanger; the commercial carboxylic acid Versatic 911 is highly efficient for this operation. Halogens present in the organic phase are readily washed out with water. Zinc and other metal values are then selectively stripped with sulfuric acid, generating a neutral solution of zinc sulfate suitable for electrolytic production of zinc metal. Alternatively, zinc sulfate can be crystallized directly from the organic phase by stripping with concentrated sulfuric acid.

  20. The zinc electrode - Its behaviour in the nickel oxide-zinc accumulator

    Science.gov (United States)

    Certain aspects of zinc electrode reaction and behavior are investigated in view of their application to batteries. The properties of the zinc electrode in a battery system are discussed, emphasizing porous structure. Shape change is emphasized as the most important factor leading to limited battery cycle life. It is shown that two existing models of shape change based on electroosmosis and current distribution are unable to consistently describe observed phenomena. The first stages of electrocrystallization are studied and the surface reactions between the silver substrate and the deposited zinc layer are investigated. The reaction mechanism of zinc and amalgamated zinc in an alkaline electrolyte is addressed, and the batter system is studied to obtain information on cycling behavior and on the shape change phenomenon. The effect on cycle behavior of diferent amalgamation techniques of the zinc electrode and several additives is addressed. Impedance measurements on zinc electrodes are considered, and battery behavior is correlated with changes in the zinc electrode during cycling.

  1. Neural Networks: Implementations and Applications

    NARCIS (Netherlands)

    Vonk, E.; Veelenturf, L.P.J.; Jain, L.C.

    1996-01-01

    Artificial neural networks, also called neural networks, have been used successfully in many fields including engineering, science and business. This paper presents the implementation of several neural network simulators and their applications in character recognition and other engineering areas

  2. What Are Neural Tube Defects?

    Science.gov (United States)

    ... NICHD Research Information Clinical Trials Resources and Publications Neural Tube Defects (NTDs): Condition Information Skip sharing on social media links Share this: Page Content What are neural tube defects? Neural (pronounced NOOR-uhl ) tube defects are ...

  3. Zinc therapy for different causes of diarrhea

    OpenAIRE

    Hafaz Zakky Abdillah; Supriatmo Supriatmo; Melda Deliana; Selvi Nafianti; Atan Baas Sinuhaji

    2013-01-01

    Background The incidence of diarrhea in Indonesia has declined in the past five years. In spite of the increasing number of studies on the treatment for acute diarrhea, especially the use of zinc, it is not known if bacterial vs. non-bacterial etiology makes a difference in the reduction of severity of acute diarrhea in children on zinc therapy. Objective To assess the effect of zinc therapy in reducing the severity of acute bacterial and non-bacterial diarrhea. Method...

  4. Morphology control of zinc regeneration for zinc-air fuel cell and battery

    Science.gov (United States)

    Wang, Keliang; Pei, Pucheng; Ma, Ze; Xu, Huachi; Li, Pengcheng; Wang, Xizhong

    2014-12-01

    Morphology control is crucial both for zinc-air batteries and for zinc-air fuel cells during zinc regeneration. Zinc dendrite should be avoided in zinc-air batteries and zinc pellets are yearned to be formed for zinc-air fuel cells. This paper is mainly to analyze the mechanism of shape change and to control the zinc morphology during charge. A numerical three-dimensional model for zinc regeneration is established with COMSOL software on the basis of ionic transport theory and electrode reaction electrochemistry, and some experiments of zinc regeneration are carried out. The deposition process is qualitatively analyzed by the kinetics Monte Carlo method to study the morphological change from the electrocrystallization point of view. Morphological evolution of deposited zinc under different conditions of direct currents and pulse currents is also investigated by simulation. The simulation shows that parametric variables of the flowing electrolyte, the surface roughness and the structure of the electrode, the charging current and mode affect morphological evolution. The uniform morphology of deposited zinc is attained at low current, pulsating current or hydrodynamic electrolyte, and granular morphology is obtained by means of an electrode of discrete columnar structure in combination with high current and flowing electrolyte.

  5. Consequence of irrigation with arsenic and zinc contaminated water on accumulation of zinc in radishes plant

    Directory of Open Access Journals (Sweden)

    Hossein Banejad

    2014-10-01

    Conclusion: It was found that zinc concentration in radish roots, tubers, and leafs is correlated with the concentration of zinc in water. Moreover, there was a competition between the absorption of zinc and arsenic in plants. With increasing arsenic in irrigation water, transition of Zn was reduced to aerial part.

  6. Reversal of uraemic impotence by zinc.

    Science.gov (United States)

    Antoniou, L D; Shalhoub, R J; Sudhakar, T; Smith, J C

    1977-10-29

    In eight impotent haemodialysed men with low plasma-zinc levels sexual function, including potency, frequency of intercourse, libido, and plasma testosterone, follicle-stimulating hormone, and luteinising hormone levels, was determined before and after therapy with zinc (four patients) or placebo (four patients). Dialytic administration of zinc strikingly improved potency in all patients and raised the plasma-testosterone to normal in the two with low pretreatment plasma-testosterone levels. Placebo did not improve sexual function in any patient. Zinc deficiency is a reversible cause of gonadal dysfunction in uraemia.

  7. Evolution of zinc morphology during continuous electrodeposition

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The morphology evolution of zinc continuous electrodeposits with nano-sized crystals on the ferrite substrate has been studied by in-situ scanning tunnel spectroscopy (STM). It is found that the morphology of zinc electrodeposits varies from initial granules with a size of about 30 nm to layered platelets with increasing deposition time. Meanwhile, the crystal structure of the zinc electrodeposits is identified to be hexagonal η-phase by X-ray diffraction. The orientation relationship between zinc crystals and the substrate surface can be interpreted in terms of the misfit and the atomic correspondence of the interphase boundary between the η-phase deposits and α-Fe substrate.

  8. Zinc and Brass in Archaeological Perspective

    Directory of Open Access Journals (Sweden)

    J. S. Kharakwal

    2006-12-01

    Full Text Available Brass has a much longer history than zinc. There has been a bit of confusion about the early beginning of zinc as several claims are made out side of India. Both literary as well as archaeological records reveal that production of pure zinc had begun in the second half of the first millennium BC, though production on commercial scale begun in the early Medieval times. This paper attempts to examine the archaeological record and literary evidence to understand the actual beginning of brass and zinc in India.

  9. Zinc absorption in inflammatory bowel disease

    Energy Technology Data Exchange (ETDEWEB)

    Valberg, L.S.; Flanagan, P.R.; Kertesz, A.; Bondy, D.C.

    1986-07-01

    Zinc absorption was measured in 29 patients with inflammatory bowel disease and a wide spectrum of disease activity to determine its relationship to disease activity, general nutritional state, and zinc status. Patients with severe disease requiring either supplementary oral or parenteral nutrition were excluded. The mean 65ZnCl2 absorption, in the patients, determined using a 65Zn and 51Cr stool-counting test, 45 +/- 17% (SD), was significantly lower than the values, 54 +/- 16%, in 30 healthy controls, P less than 0.05. Low 65ZnCl2 absorption was related to undernutrition, but not to disease activity in the absence of undernutrition or to zinc status estimated by leukocyte zinc measurements. Mean plasma zinc or leukocyte zinc concentrations in patients did not differ significantly from controls, and only two patients with moderate disease had leukocyte zinc values below the 5th percentile of normal. In another group of nine patients with inflammatory bowel disease of mild-to-moderate severity and minimal nutritional impairment, 65Zn absorption from an extrinsically labeled turkey test meal was 31 +/- 10% compared to 33 +/- 7% in 17 healthy controls, P greater than 0.1. Thus, impairment in 65ZnCl2 absorption in the patients selected for this study was only evident in undernourished persons with moderate or severe disease activity, but biochemical evidence of zinc deficiency was uncommon, and clinical features of zinc depletion were not encountered.

  10. Zinc oxide varistor; Sanka aen barisuta

    Energy Technology Data Exchange (ETDEWEB)

    Igarashi, H.

    2000-01-01

    Characteristics of zinc oxide varistors, applications to electronic equipment protection and to power arrester are explained. Zinc oxide varistors were invented in Japan, which function by ceramics boundary phenomena and are applied to various fields from power plants to houses. Zinc oxide varistors protect electronic equipment from malfunctions and destructions by surge voltage, accordingly have spread rapidly. Protection performance of the power arresters has been improved by development of zinc oxide varistors for electric power, and power arresters came to be used to protect electric lines all over the world. (NEDO)

  11. Critical Branching Neural Networks

    Science.gov (United States)

    Kello, Christopher T.

    2013-01-01

    It is now well-established that intrinsic variations in human neural and behavioral activity tend to exhibit scaling laws in their fluctuations and distributions. The meaning of these scaling laws is an ongoing matter of debate between isolable causes versus pervasive causes. A spiking neural network model is presented that self-tunes to critical…

  12. Kunstige neurale net

    DEFF Research Database (Denmark)

    Hørning, Annette

    1994-01-01

    Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse.......Artiklen beskæftiger sig med muligheden for at anvende kunstige neurale net i forbindelse med datamatisk procession af naturligt sprog, specielt automatisk talegenkendelse....

  13. Is neural Darwinism Darwinism?

    Science.gov (United States)

    van Belle, T

    1997-01-01

    Neural Darwinism is a theory of cognition developed by Gerald Edelman along with George Reeke and Olaf Sporns at Rockefeller University. As its name suggests, neural Darwinism is modeled after biological Darwinism, and its authors assert that the two processes are strongly analogous. both operate on variation in a population, amplifying the more adaptive individuals. However, from a computational perspective, neural Darwinism is quite different from other models of natural selection, such as genetic algorithms. The individuals of neural Darwinism do not replicate, thus robbing the process of the capacity to explore new solutions over time and ultimately reducing it to a random search. Because neural Darwinism does not have the computational power of a truly Darwinian process, it is misleading to label it as such. to illustrate this disparity in adaptive power, one of Edelman's early computer experiments, Darwin I, is revisited, and it is shown that adding replication greatly improves the adaptive power of the system.

  14. Dosage Effect of Zinc Glycine Chelate on Zinc Metabolism and Gene Expression of Zinc Transporter in Intestinal Segments on Rat.

    Science.gov (United States)

    Huang, Danping; Hu, Qiaoling; Fang, Shenglin; Feng, Jie

    2016-06-01

    Zinc plays an essential role in various fundamental biological processes. The focus of this research was to investigate the dosage effect of zinc glycine chelate (Zn-Gly) on zinc metabolism and the gene expression of zinc transporters in intestinal segments. A total of 30 4-week-old SD rats were randomized into five treatment groups. The basal diets for each group were supplemented with gradient levels of Zn (0, 30, 60, 90, and 180 mg/kg) from Zn-Gly. After 1-week experiment, the results showed that serum and hepatic zinc concentration were elevated linearly with supplemental Zn levels from 0 to 180 mg Zn/kg. Serum Cu-Zn SOD activities resulted in a significant (P zinc levels (P zinc content and was significantly higher (P zinc levels and the activities of Cu-Zn SOD and AKP on rats. Dietary Zn-Gly has a certain effect on MT1, Zip4, Zip5, and ZnT1 expression, which expressed differently in intestinal segments with different levels of Zn-Gly load. Besides, Zn-Gly also could regulate PepT1 expression in intestinal segments.

  15. Monte Carlo simulation of zinc protoporphyrin fluorescence in the retina

    Science.gov (United States)

    Chen, Xiaoyan; Lane, Stephen

    2010-02-01

    We have used Monte Carlo simulation of autofluorescence in the retina to determine that noninvasive detection of nutritional iron deficiency is possible. Nutritional iron deficiency (which leads to iron deficiency anemia) affects more than 2 billion people worldwide, and there is an urgent need for a simple, noninvasive diagnostic test. Zinc protoporphyrin (ZPP) is a fluorescent compound that accumulates in red blood cells and is used as a biomarker for nutritional iron deficiency. We developed a computational model of the eye, using parameters that were identified either by literature search, or by direct experimental measurement to test the possibility of detecting ZPP non-invasively in retina. By incorporating fluorescence into Steven Jacques' original code for multi-layered tissue, we performed Monte Carlo simulation of fluorescence in the retina and determined that if the beam is not focused on a blood vessel in a neural retina layer or if part of light is hitting the vessel, ZPP fluorescence will be 10-200 times higher than background lipofuscin fluorescence coming from the retinal pigment epithelium (RPE) layer directly below. In addition we found that if the light can be focused entirely onto a blood vessel in the neural retina layer, the fluorescence signal comes only from ZPP. The fluorescence from layers below in this second situation does not contribute to the signal. Therefore, the possibility that a device could potentially be built and detect ZPP fluorescence in retina looks very promising.

  16. Clinical Aspects of Trace Elements: Zinc in Human Nutrition - Assessment of Zinc Status

    Directory of Open Access Journals (Sweden)

    Michelle M Pluhator

    1996-01-01

    Full Text Available Because the limiting and vulnerable zinc pool has not been identified, it becomes a challenge to determine which of the many zinc pools is most susceptible to deficiency. As a consequence, defining and assessing zinc status in the individual patient is a somewhat uncertain process. Laboratory analysis of zinc status is difficult because no single biochemical criterion can reliably reflect zinc body stores. Many indexes have been examined in the hopes of discovering a method for the assessment of zinc nutriture. None of the methods currently used can be wholeheartedly recommended because they are fraught with problems that affect their use and interpretation. However, these methods remain in use for clinical and research purposes, though their benefits and drawbacks must always be acknowledged. Until an acceptable method of analysis is discovered, clinicians must rely for confirmation of zinc deficiency on a process of supplementing with zinc and observing the patient’s response. The main indexes (plasma/serum, erythrocyte, leukocyte, neutrophil, urine, hair and salivary zinc levels, taste acuity and oral zinc tolerance tests, and measurement of metallothionein levels are reviewed. Measurement of plasma or erythrocyte metallothionein levels shows promise as a future tool for the accurate determination of zinc status.

  17. The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

    Directory of Open Access Journals (Sweden)

    Cuong D. Tran

    2015-05-01

    Full Text Available It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease.

  18. Solubilization and Transformation of Insoluble Zinc Compounds by Fungi Isolated from a Zinc Mine

    Directory of Open Access Journals (Sweden)

    Thanawat Sutjaritvorakul

    2013-07-01

    Full Text Available Fungi were isolated from zinc-containing rocks and mining soil. They were screened for the ability to solubilize and transform three insoluble zinc compounds: ZnO, Zn3(PO4, and ZnCO3. Fungi were plated on potato dextrose agar (PDA medium which was supplemented with 0.5% (w/v of insoluble zinc compounds. Of the strains tested, four fungal isolates showed the highest efficiency for solubilizing all the insoluble zinc compounds, producing clearing zone diameters > 40 mm. These were identified as a Phomopsis spp., Aspergillus sp.1, Aspergillus sp.2, and Aspergillus niger. Zinc oxide was the most easily solubilized compound and it was found that 87%, 52%, and 61% of the tested fungi (23 isolates were able to solubilize zinc oxide, zinc phosphate, and zinc carbonate, respectively. Precipitation of zinc-containing crystals was observed in zinc oxide-containing agar medium underneath colonies of Aspergillus sp.1, and these were identified as zinc oxalate. It is suggested that these kinds of fungi have the potential application in bioremediation practices for heavy metal contaminated soils.

  19. Zinc-regulated DNA binding of the yeast Zap1 zinc-responsive activator.

    Directory of Open Access Journals (Sweden)

    Avery G Frey

    Full Text Available The Zap1 transcription factor of Saccharomyces cerevisiae plays a central role in zinc homeostasis by controlling the expression of genes involved in zinc metabolism. Zap1 is active in zinc-limited cells and repressed in replete cells. At the transcriptional level, Zap1 controls its own expression via positive autoregulation. In addition, Zap1's two activation domains are regulated independently of each other by zinc binding directly to those regions and repressing activation function. In this report, we show that Zap1 DNA binding is also inhibited by zinc. DMS footprinting showed that Zap1 target gene promoter occupancy is regulated with or without transcriptional autoregulation. These results were confirmed using chromatin immunoprecipitation. Zinc regulation of DNA binding activity mapped to the DNA binding domain indicating other parts of Zap1 are unnecessary for this control. Overexpression of Zap1 overrode DNA binding regulation and resulted in constitutive promoter occupancy. Under these conditions of constitutive binding, both the zinc dose response of Zap1 activity and cellular zinc accumulation were altered suggesting the importance of DNA binding control to zinc homeostasis. Thus, our results indicated that zinc regulates Zap1 activity post-translationally via three independent mechanisms, all of which contribute to the overall zinc responsiveness of Zap1.

  20. Bidirectional reflectance of zinc oxide

    Science.gov (United States)

    Scott, R.

    1973-01-01

    This investigation was undertaken to determine original and useful information about the bidirection reflectance of zinc oxide. The bidirectional reflectance will be studied for the spectra between .25-2.5 microns and the hemisphere above the specimen. The following factors will be considered: (1) surface conditions; (2) specimen preparation; (3) specimen substrate, (4) polarization; (5) depolarization; (6) wavelength; and (7) angles of incident and reflection. The bidirectional reflectance will be checked by experimentally determined angular hemispherical measurements or hemispherical measurements will be used to obtain absolute bidirectional reflectance.

  1. Intravenous zinc therapy for acquired zinc deficiency secondary to gastric bypass surgery: a case report.

    Science.gov (United States)

    Vick, Garrett; Mahmoudizad, Rod; Fiala, Katherine

    2015-01-01

    Zinc deficiency may result from either a congenitally inherited defect of zinc absorption or is acquired secondarily from a variety of factors affecting dietary zinc intake, absorption, or loss. We report a case of acquired zinc deficiency secondary to gastric bypass surgery that resulted in vulvar cutaneous manifestations of delayed onset, with failure to clear after oral supplementation with zinc. The patient experienced improvement of symptoms only after administration of intravenous zinc supplementation. Upon review of the current literature, it is thought that the patient's original suboptimal response to oral supplementation and improvement after receiving intravenous zinc were related to the intentional surgical alteration and bypass of the absorptive capacity of the duodenum and jejunum. With the current prevalence of obesity and availability of surgical weight loss therapies, it is important to be mindful of the resulting nutritional deficiencies, their clinical manifestations, and factors affecting the efficacy of therapeutic approaches as seen in this case.

  2. Dynamics of neural cryptography.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

    2007-05-01

    Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible.

  3. Zinc dosing and glucose tolerance in humans

    Energy Technology Data Exchange (ETDEWEB)

    Greenley, S.; Taylor, M.

    1986-03-05

    Animal data suggest the existence of a physiologic relationship between glucoregulatory hormones and zinc metabolism. In order to investigate this proposed relationship in humans, they examined the effect of moderately elevated plasma zinc levels on blood glucose clearance. Eight women (24-37 yrs) served as subjects for the study. Fasted volunteers were tested under two experimental conditions (a) ingestion of 50 g D-glucose (b) ingestion of 25 mg zinc followed 60 min later by ingestion of 50 g D-glucose. Five ml venous blood was drawn into trace-metal-free, fluoride-containing vacutainer tubes prior to and 15, 30, 45, 60, 90, and 120 min after glucose ingestion. Plasma was analyzed for glucose and zinc; glycemic responses were quantified by computing areas under the curves and times to peak concentration. Their human data indicate varied glycemic responses to the acute elevation of plasma zinc: 4 subjects showed little apparent effect; 3 subjects marginally increased either the area under the curve or time to peak and 1 subject (classified as suspect diabetic in the non-zinc condition) showed marked improvement in glycemic response following zinc ingestion. Their preliminary results suggest that blood glucose clearance may be affected in some individuals by the acute elevation of plasma zinc.

  4. AUV fuzzy neural BDI

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The typical BDI (belief desire intention) model of agent is not efficiently computable and the strict logic expression is not easily applicable to the AUV (autonomous underwater vehicle) domain with uncertainties. In this paper, an AUV fuzzy neural BDI model is proposed. The model is a fuzzy neural network composed of five layers: input ( beliefs and desires) , fuzzification, commitment, fuzzy intention, and defuzzification layer. In the model, the fuzzy commitment rules and neural network are combined to form intentions from beliefs and desires. The model is demonstrated by solving PEG (pursuit-evasion game), and the simulation result is satisfactory.

  5. ANT Advanced Neural Tool

    Energy Technology Data Exchange (ETDEWEB)

    Labrador, I.; Carrasco, R.; Martinez, L.

    1996-07-01

    This paper describes a practical introduction to the use of Artificial Neural Networks. Artificial Neural Nets are often used as an alternative to the traditional symbolic manipulation and first order logic used in Artificial Intelligence, due the high degree of difficulty to solve problems that can not be handled by programmers using algorithmic strategies. As a particular case of Neural Net a Multilayer Perception developed by programming in C language on OS9 real time operating system is presented. A detailed description about the program structure and practical use are included. Finally, several application examples that have been treated with the tool are presented, and some suggestions about hardware implementations. (Author) 15 refs.

  6. Recent advances in zinc-air batteries.

    Science.gov (United States)

    Li, Yanguang; Dai, Hongjie

    2014-08-07

    Zinc-air is a century-old battery technology but has attracted revived interest recently. With larger storage capacity at a fraction of the cost compared to lithium-ion, zinc-air batteries clearly represent one of the most viable future options to powering electric vehicles. However, some technical problems associated with them have yet to be resolved. In this review, we present the fundamentals, challenges and latest exciting advances related to zinc-air research. Detailed discussion will be organized around the individual components of the system - from zinc electrodes, electrolytes, and separators to air electrodes and oxygen electrocatalysts in sequential order for both primary and electrically/mechanically rechargeable types. The detrimental effect of CO2 on battery performance is also emphasized, and possible solutions summarized. Finally, other metal-air batteries are briefly overviewed and compared in favor of zinc-air.

  7. AMPA receptor inhibition by synaptically released zinc.

    Science.gov (United States)

    Kalappa, Bopanna I; Anderson, Charles T; Goldberg, Jacob M; Lippard, Stephen J; Tzounopoulos, Thanos

    2015-12-22

    The vast amount of fast excitatory neurotransmission in the mammalian central nervous system is mediated by AMPA-subtype glutamate receptors (AMPARs). As a result, AMPAR-mediated synaptic transmission is implicated in nearly all aspects of brain development, function, and plasticity. Despite the central role of AMPARs in neurobiology, the fine-tuning of synaptic AMPA responses by endogenous modulators remains poorly understood. Here we provide evidence that endogenous zinc, released by single presynaptic action potentials, inhibits synaptic AMPA currents in the dorsal cochlear nucleus (DCN) and hippocampus. Exposure to loud sound reduces presynaptic zinc levels in the DCN and abolishes zinc inhibition, implicating zinc in experience-dependent AMPAR synaptic plasticity. Our results establish zinc as an activity-dependent, endogenous modulator of AMPARs that tunes fast excitatory neurotransmission and plasticity in glutamatergic synapses.

  8. Flunarizine and lamotngine propnyiaxis effects on neuron-specific enolase,S-100,and brain-specific creatine kinase in a fetal rat model of hypoxic-ischemic brain damage

    Institute of Scientific and Technical Information of China (English)

    Li He; Jingyi Deng; Wendan He

    2008-01-01

    BACKGROUND:Calcium antagonists may act as neuroprotectants,diminishing the influx of calcium ions through voltage-sensitive calcium channels. When administered prophylactically,they display neuroprotective effects against hypoxic-ischemic brain damage in newborn rats.OBJECTIVE:To investigate the neuroprotective effects of flunarizine(FNZ),lamotrigine (LTG)and the combination of both drugs,on hypoxic-ischemic brain damage in fetal rats.DESIGN AND SETTING:This randomized,complete block design was performed at the Department of Pediatrics.Shenzhen Fourth People's Hospital,Guangdong Medical College.MATERIALS:Forty pregnant Wistar rats,at gestational day 20,were selected for the experiment and were randomly divided into FNZ,LTG,FNZ+LTG,and model groups,with 10 rats in each group.METHODS:Rats in the FNZ.LTG,and FNZ+LTG groups received intragastric injections of FNZ (0.5 mg/kg/d),LTG(10 mg/kg/d),and FNZ(0.5 mg/kg/d)+LTG(10 mg/kg/d),respectively.Drugs were administered once a day for 3 days prior to induction of hypoxia-ischemia.Rats in the modeJ group were not administered any drugs.Three hours after the final administration,eight pregnant rats from each group underwent model establishment hypoxia-ischemia brain damage to the fetal rats.Cesareans were performed at 6,12,24,and 48 hours later;and 5 fetal rats were removed from each mother and kept warm.Twe fetuses without model establishment were removed by planned cesarean at the same time and served as controls.A total of 0.3 mL serum was collected from fetal rats at 6,12,24,and 48 hours,respectively,following birth.MAIN OUTCOME MEASURES:Serum protein concentrations of neuron-specific enolase and S-100 were measured by ELISA.Serum concentrations of brain-specific creatine kinase were measured using an electrogenerated chemiluminescence method.RESULTS:Serum concentrations of neuron-specific enolase,S-100,and brain-specific creatine kinase were significantly higher in the hypoxic-ischemic fetal rats.compared with the non

  9. Thermodynamic Modeling of Zinc Speciation in Electric Arc Furnace Dust

    Science.gov (United States)

    Pickles, Chris A.

    2011-04-01

    The remelting of automobile scrap, containing galvanized steel, in an electric arc furnace (EAF) results in the generation of a dust, which contains considerable amounts of zinc and other metals. Typically, the amount of zinc is of significant commercial value, but the recovery of this metal can be hindered by the varied speciation of zinc. The majority of the zinc exists as zincite (ZnO) and zinc ferrite (ZnFe2O4) or ferritic spinels ((Zn x Mn y Fe1-x-y )Fe2O4), but other zinccontaining species such as zinc chloride, zinc hydroxide chlorides, hydrated zinc sulphates and zinc silicates have also been identified. There is a scarcity of research literature on the thermodynamic aspects of the formation of these zinc-containing species, in particular, the minor zinc-containing species. Therefore, in this study, the equilibrium module of HSC Chemistry® 6.1 was utilized to calculate the types and the amounts of the zinc-containing species. The variables studied were: the gas composition, the temperature and the dust composition. At high temperatures, zincite forms via the reaction of zinc vapour with oxygen gas and the zinc-manganese ferrites form as a result of the reaction of iron-manganese particles with zinc vapour and oxygen. At intermediate temperatures, zinc sulphates are produced through the reaction of zinc oxide and sulphur dioxide gas. As room temperature is approached, zinc chlorides and fluorides form by the reaction of zinc oxide with hydrogen chloride and hydrogen fluoride gases, respectively. Zinc silicate likely forms via the high temperature reaction of zinc vapour and oxygen with silica. In the presence of excess water and as room temperature is approached, the zinc sulphates, chlorides and fluorides can become hydrated.

  10. Effects of zinc supplementation and zinc chelation on in vitro β-cell function in INS-1E cells

    DEFF Research Database (Denmark)

    Nygaard, Sanne Bjørn; Larsen, Agnete; Knuhtsen, Astrid;

    2014-01-01

    BACKGROUND: Zinc is essential for the activities of pancreatic β-cells, especially insulin storage and secretion. Insulin secretion leads to co-release of zinc which contributes to the paracrine communication in the pancreatic islets. Zinc-transporting proteins (zinc-regulated transporter, iron......-regulated transporter-like proteins [ZIPs] and zinc transporters [ZnTs]) and metal-buffering proteins (metallothioneins, MTs) tightly regulate intracellular zinc homeostasis. The present study investigated how modulation of cellular zinc availability affects β-cell function using INS-1E cells. RESULTS: Using INS-1E...... cells, we found that zinc supplementation and zinc chelation had significant effects on insulin content and insulin secretion. Supplemental zinc within the physiological concentration range induced insulin secretion. Insulin content was reduced by zinc chelation with N,N,N',N-tektrakis(2-pyridylmethyl...

  11. Zinc distribution in blood components, inflammatory status, and clinical indexes of disease activity during zinc supplementation in inflammatory rheumatic diseases.

    Science.gov (United States)

    Peretz, A; Nève, J; Jeghers, O; Pelen, F

    1993-05-01

    The effects of zinc supplementation on zinc status and on clinical and biological indicators of inflammation were investigated in 18 patients with chronic inflammatory rheumatic diseases and in 9 healthy control subjects. Patients with mild and recent onset disease were assigned to a 60-d trial to receive either 45 mg Zn (as gluconate)/d or a placebo, while control subjects received the zinc supplement. Baseline mean plasma zinc of the patients was low whereas mononuclear cell zinc content was elevated, suggesting a redistribution of the element related to the inflammatory process rather than to a zinc-deficient state. Zinc supplementation increased plasma zinc to a similar extent in patients and in control subjects, which suggested no impairment of zinc intestinal absorption as a result of the inflammatory process. On the contrary, erythrocyte and leukocyte zinc concentrations were not modified in the two groups examined. No beneficial effect of zinc treatment could be demonstrated on either clinical or inflammation indexes.

  12. Neural networks and graph theory

    Institute of Scientific and Technical Information of China (English)

    许进; 保铮

    2002-01-01

    The relationships between artificial neural networks and graph theory are considered in detail. The applications of artificial neural networks to many difficult problems of graph theory, especially NP-complete problems, and the applications of graph theory to artificial neural networks are discussed. For example graph theory is used to study the pattern classification problem on the discrete type feedforward neural networks, and the stability analysis of feedback artificial neural networks etc.

  13. Hidden neural networks

    DEFF Research Database (Denmark)

    Krogh, Anders Stærmose; Riis, Søren Kamaric

    1999-01-01

    A general framework for hybrids of hidden Markov models (HMMs) and neural networks (NNs) called hidden neural networks (HNNs) is described. The article begins by reviewing standard HMMs and estimation by conditional maximum likelihood, which is used by the HNN. In the HNN, the usual HMM probability...... parameters are replaced by the outputs of state-specific neural networks. As opposed to many other hybrids, the HNN is normalized globally and therefore has a valid probabilistic interpretation. All parameters in the HNN are estimated simultaneously according to the discriminative conditional maximum...... likelihood criterion. The HNN can be viewed as an undirected probabilistic independence network (a graphical model), where the neural networks provide a compact representation of the clique functions. An evaluation of the HNN on the task of recognizing broad phoneme classes in the TIMIT database shows clear...

  14. Critical branching neural networks.

    Science.gov (United States)

    Kello, Christopher T

    2013-01-01

    It is now well-established that intrinsic variations in human neural and behavioral activity tend to exhibit scaling laws in their fluctuations and distributions. The meaning of these scaling laws is an ongoing matter of debate between isolable causes versus pervasive causes. A spiking neural network model is presented that self-tunes to critical branching and, in doing so, simulates observed scaling laws as pervasive to neural and behavioral activity. These scaling laws are related to neural and cognitive functions, in that critical branching is shown to yield spiking activity with maximal memory and encoding capacities when analyzed using reservoir computing techniques. The model is also shown to account for findings of pervasive 1/f scaling in speech and cued response behaviors that are difficult to explain by isolable causes. Issues and questions raised by the model and its results are discussed from the perspectives of physics, neuroscience, computer and information sciences, and psychological and cognitive sciences.

  15. Neural Oscillators Programming Simplified

    Directory of Open Access Journals (Sweden)

    Patrick McDowell

    2012-01-01

    Full Text Available The neurological mechanism used for generating rhythmic patterns for functions such as swallowing, walking, and chewing has been modeled computationally by the neural oscillator. It has been widely studied by biologists to model various aspects of organisms and by computer scientists and robotics engineers as a method for controlling and coordinating the gaits of walking robots. Although there has been significant study in this area, it is difficult to find basic guidelines for programming neural oscillators. In this paper, the authors approach neural oscillators from a programmer’s point of view, providing background and examples for developing neural oscillators to generate rhythmic patterns that can be used in biological modeling and robotics applications.

  16. Serum zinc levels in gestational diabetes

    Directory of Open Access Journals (Sweden)

    Rahimi Sharbaf F

    2008-12-01

    Full Text Available "nBackground: Maternal zinc deficiency during pregnancy has been related to adverse pregnancy outcomes. Most studies in which pregnant women have been supplemented with zinc to examine its effects on the outcome of the pregnancy have been carried out in industrialized countries and the results have been inconclusive. It has been shown that women with gestational diabetes (GDM have lower serum zinc levels than healthy pregnant women, and higher rates of macrosomia. Zinc is required for normal glucose metabolism, and strengthens the insulin-induced transportation of glucose into cells by its effect on the insulin signaling pathway. The purpose of this study was to assess the serum zinc levels of GDM patients and evaluate the effect of zinc supplementation. "nMethods: In the first stage of this prospective controlled study, we enrolled 70 women who were 24-28 weeks pregnant at the Prenatal Care Center of Mirza Kochak Khan Hospital, Tehran, Iran. The serum zinc level of each subject was determined. In the second stage, among these 70 subjects, the diabetics receiving insulin were divided into two groups, only one of which received a zinc supplement and the other group was the control group. Birth weight of neonates and insulin dosages were recorded. "nResults: The mean serum zinc level in the GDM group was lower than that of the control group (94.83 vs. 103.49mg/dl, respectively and the mean birth weight of neonates from the GDM women who received the zinc supplement was lower than that of the control group (3849g vs. 4136g. The rate of macrosomia was lower in the zinc supplemented group (20% vs. 53%. The mean of increase of insulin after receiving the zinc supplement was lower (8.4u vs. 13.53. "nConclusion: Maternal insulin resistance is associated with the accumulation of maternal fat tissue during early stages of pregnancy and greater fetoplacental nutrient availability in later stages, when 70% of fetal growth occurs, resulting in macrosomia. In

  17. Imaging the Neural Symphony.

    Science.gov (United States)

    Svoboda, Karel

    2016-01-01

    Since the start of the new millennium, a method called two-photon microscopy has allowed scientists to peer farther into the brain than ever before. Our author, one of the pioneers in the development of this new technology, writes that "directly observing the dynamics of neural networks in an intact brain has become one of the holy grails of brain research." His article describes the advances that led to this remarkable breakthrough-one that is helping neuroscientists better understand neural networks.

  18. Building a Neural Computer

    OpenAIRE

    1998-01-01

    In the work of [Siegelmann 95] it was showed that Artificial Recursive Neural Networks have the same computing power as Turing machines. A Turing machine can be programmed in a proper high-level language - the language of partial recursive functions. In this paper we present the implementation of a compiler that directly translates high-level Turing machine programs to Artificial Recursive Neural Networks. The application contains a simulator that can be used to test the resulting networks. W...

  19. Neural cryptography with feedback.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Shacham, Lanir; Kanter, Ido

    2004-04-01

    Neural cryptography is based on a competition between attractive and repulsive stochastic forces. A feedback mechanism is added to neural cryptography which increases the repulsive forces. Using numerical simulations and an analytic approach, the probability of a successful attack is calculated for different model parameters. Scaling laws are derived which show that feedback improves the security of the system. In addition, a network with feedback generates a pseudorandom bit sequence which can be used to encrypt and decrypt a secret message.

  20. Studies on the bioavailability of zinc in humans: intestinal interaction of tin and zinc.

    Science.gov (United States)

    Solomons, N W; Marchini, J S; Duarte-Favaro, R M; Vannuchi, H; Dutra de Oliveira, J E

    1983-04-01

    Mineral/mineral interactions at the intestinal level are important in animal nutrition and toxicology, but only limited understanding of their extent or importance in humans has been developed. An inhibitory interaction of dietary tin on zinc retention has been recently described from human metabolic studies. We have explored the tin/zinc interaction using the change-in-plasma-zinc-concentration method with a standard dosage of 12.5 mg of zinc as zinc sulfate in 100 ml of Coca-Cola. Sn/Zn ratios of 2:1, 4:1, and 8:1, constituted by addition of 25, 50, and 100 mg of tin as stannous chloride, had no significant overall effect on zinc uptake. The 100-mg dose of tin produced noxious gastrointestinal symptoms. Addition of iron as ferrous sulfate to form ratios of Sn/Fe/Zn of 1:1:1 and 2:2:1 with the standard zinc solution and the appropriate doses of tin produced a reduction of zinc absorption not dissimilar from that seen previously with zinc and iron alone, and addition of picolinic acid did not influence the uptake of zinc from the solution with the 2:2:1 Sn/Fe/Zn ratio.

  1. Zinc-Laccase Biofuel Cell

    Directory of Open Access Journals (Sweden)

    Abdul Aziz Ahmad

    2011-12-01

    Full Text Available A zinc-laccase biofuel cell adapting the zinc-air cell design features is investigated. A simple cell design configuration is employed: a membraneless single chamber and a freely suspended laccase in a quasi-neutral buffer electrolyte. The cell is characterised according to its open-circuit voltage, polarization profile, power density plot and discharge capacity at constant current. The biocatalytic role of laccase is evident from the polarization profile and power output plot. Performance comparison between a single chamber and dual chamber cell design is also presented. The biofuel cell possessed an open-circuit voltage of 1.2 V and delivered a maximum power density of 0.9 mW/cm2 at current density of 2.5 mA/cm2. These characteristics are comparable to biofuel cell utilising a much more complex system design.KEY WORDS (keyword:  Biofuel cell, Bioelectrochemical cell, Zinc anode, Laccase and Oxidoreductase.ABSTRAK: Sel bio-bahan api zink-laccase dengan adaptasi daripada ciri-ciri rekabentuk sel zink-udara telah dikaji. Sel dengan konfigurasi rekabentuk yang mudah digunapakai: ruangan tunggal tanpa membran dan laccase diampaikan secara bebas di dalam elektrolit pemampan quasi-neutral. Sel dicirikan berdasarkan voltan litar terbuka, profil polarisasi, plot ketumpatan kuasa dan kapasiti discas pada arus malar. Peranan laccase sebagai bio-pemangkin adalah amat ketara daripada profil polarisasi dan plot ketumpatan kuasa. Perbandingan prestasi di antara sel dengan rekabentuk ruangan tunggal and dwi-ruangan turut diketengahkan. Seperti dijangkakan, sel dengan rekabentuk ruangan tunggal menunjukkan kuasa keluaran yang lebih rendah jika dibandingkan dengan rekabentuk dwi-ruangan kemungkinan disebabkan fenomena cas bocor. Sel bio-bahan api ini mempunyai voltan litar terbuka 1.2 V dan memberikan ketumpatan kuasa maksima 0.9 mW/cm2 pada ketumpatan arus 2.5 mA/cm2. Ciri-ciri ini adalah sebanding dengan sel bio-bahan api yang menggunapakai rekabentuk sel

  2. Interactions of cadmium and zinc during pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Sorell, T.L.

    1988-01-01

    The interactions of cadmium exposure and zinc during pregnancy were investigated by studying rats exposed to 0, 5, 50, or 100 ppm cadmium (as CdCl{sub 2}) in the drinking water from day 6 to day 20 of pregnancy. On day 20 of pregnancy, fetuses of rats exposed to 50 and 100 ppm of cadmium were slightly but significantly smaller than those of control animals. Fetal weight was negatively correlated with fetal cadmium concentration and positively correlated with fetal cadmium concentration. Significant fetal cadmium accumulation occurred in both the 50 and 100 ppm cadmium exposure groups; fetal zinc concentrations were decreased. Maternal liver and kidney zinc concentrations were slightly elevated, and the possible role of maternal organ sequestration of available zinc is discussed. The activity of two zinc metalloenzymes, alkaline phosphatase and {delta}-aminolevulinic acid dehydratase, was decreased in maternal and fetal tissues, providing evidence of an alteration in zinc metabolism. In addition, the placental transport of {sup 65}Zn was characterized in control animals and compared to exposed groups; placental zinc transport was significantly decreased in the 50 and 100 ppm exposure groups.

  3. ZINC MITIGATION INTERIM REPORT - THERMODYNAMIC STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Korinko, P.

    2010-12-17

    An experimental program was initiated in order to develop and validate conditions that will effectively trap Zn vapors that are released during extraction. The proposed work is broken down into three tasks. The first task is to determine the effectiveness of various pore sizes of filter elements. The second task is to determine the effect of filter temperature on zinc vapor deposition. The final task is to determine whether the zinc vapors can be chemically bound. The approach for chemically binding the zinc vapors has two subtasks, the first is a review of literature and thermodynamic calculations and the second is an experimental approach using the best candidates. This report details the results of the thermodynamic calculations to determine feasibility of chemically binding the zinc vapors within the furnace module, specifically the lithium trap (1). A review of phase diagrams, literature, and thermodynamic calculations was conducted to determine if there are suitable materials to capture zinc vapor within the lithium trap of the extraction basket. While numerous elements exist that form compounds with zinc, many of these also form compounds with hydrogen or the water that is present in the TPBARs. This relatively comprehensive review of available data indicates that elemental cobalt and copper and molybdenum trioxide (MoO3) may have the requisite properties to capture zinc and yet not be adversely affected by the extraction gases and should be considered for testing.

  4. Zinc Binding by Lactic Acid Bacteria

    Directory of Open Access Journals (Sweden)

    Jasna Mrvčić

    2009-01-01

    Full Text Available Zinc is an essential trace element in all organisms. A common method for the prevention of zinc deficiency is pharmacological supplementation, especially in a highly available form of a metalloprotein complex. The potential of different microbes to bind essential and toxic heavy metals has recently been recognized. In this work, biosorption of zinc by lactic acid bacteria (LAB has been investigated. Specific LAB were assessed for their ability to bind zinc from a water solution. Significant amount of zinc ions was bound, and this binding was found to be LAB species-specific. Differences among the species in binding performance at a concentration range between 10–90 mg/L were evaluated with Langmuir model for biosorption. Binding of zinc was a fast process, strongly influenced by ionic strength, pH, biomass concentration, and temperature. The most effective metal-binding LAB species was Leuconostoc mesenteroides (27.10 mg of Zn2+ per gram of dry mass bound at pH=5 and 32 °C, during 24 h. FT-IR spectroscopy analysis and electron microscopy demonstrated that passive adsorption and active uptake of the zinc ions were involved.

  5. Implication of zinc excess on soil health.

    Science.gov (United States)

    Wyszkowska, Jadwiga; Boros-Lajszner, Edyta; Borowik, Agata; Baćmaga, Małgorzata; Kucharski, Jan; Tomkiel, Monika

    2016-01-01

    This study was undertaken to evaluate zinc's influence on the resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease. The experiment was conducted in a greenhouse of the University of Warmia and Mazury (UWM) in Olsztyn, Poland. Plastic pots were filled with 3 kg of sandy loam with pHKCl - 7.0 each. The experimental variables were: zinc applied to soil at six doses: 100, 300, 600, 1,200, 2,400 and 4,800 mg of Zn(2+) kg(-1) in the form of ZnCl2 (zinc chloride), and species of plant: oat (Avena sativa L.) cv. Chwat and white mustard (Sinapis alba) cv. Rota. Soil without the addition of zinc served as the control. During the growing season, soil samples were subjected to microbiological analyses on experimental days 25 and 50 to determine the abundance of organotrophic bacteria, actinomyces and fungi, and the activity of dehydrogenases, catalase and urease, which provided a basis for determining the soil resistance index (RS). The physicochemical properties of soil were determined after harvest. The results of this study indicate that excessive concentrations of zinc have an adverse impact on microbial growth and the activity of soil enzymes. The resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease decreased with an increase in the degree of soil contamination with zinc. Dehydrogenases were most sensitive and urease was least sensitive to soil contamination with zinc. Zinc also exerted an adverse influence on the physicochemical properties of soil and plant development. The growth of oat and white mustard plants was almost completely inhibited in response to the highest zinc doses of 2,400 and 4,800 mg Zn(2+) kg(-1).

  6. Preparation of zinc oxide particles by using layered basic zinc acetate as a precursor

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Lanqin, E-mail: lanqin_tang@ycit.edu.cn [College of Chemical and Biological Engineering, Yancheng Institute of Technology, 9 Yingbin Avenue, Yancheng 224051 (China); College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Ding, Xuefeng; Zhao, Xu; Wang, Zichen; Zhou, Bing [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer A simple aqueous solution process has been applied to prepare zinc oxide particles. Black-Right-Pointing-Pointer This novel method exempts traditional calcinations. Black-Right-Pointing-Pointer Various zinc oxide particles are obtained. - Abstract: TEA and NaOH are applied to transform layered basic zinc acetate into zinc oxide particles by a simple aqueous solution process (<100 Degree-Sign C). Zinc oxide with different morphologies, including dumbbells, earthnuts, ellipsoids and hexagonal pillars, are obtained by carefully controlling the amounts of sodium hydroxide, triethanolamine, and reaction temperature. Field emission scanning electron microscope images, X-ray powder diffraction patterns, X-ray photoelectron spectroscopy spectra and room-temperature photoluminescence spectra are used to characterize final products. Furthermore, a possible growth mechanism is discussed in this paper. This easy procedure for zinc oxide fabrication offers the possibility of a generalized approach to the production of metal oxide with tunable morphology.

  7. Clinical Aspects of Trace Elements: Zinc in Human Nutrition – Zinc Deficiency and Toxicity

    Directory of Open Access Journals (Sweden)

    Michelle M Pluhator

    1996-01-01

    Full Text Available Available evidence suggests that trace elements, such as zinc, once thought to have no nutritional relevance, are possibly deficient in large sections of the human population. Conditioned deficiencies have been reported to result from malabsorption syndromes, acrodermatitis enteropathica, alcoholism, gastrointestinal disease, thermal injury, chronic diseases (eg, diabetes, sickle cell anemia, and in total parenteral nutrition therapy. Awareness that patients with these problems are at risk has led health professionals to focus increasingly on the importance of zinc therapy in the prevention and treatment of deficiency. More recently zinc toxicity and its role in human nutrition and well-being have come under investigation. Reports have focused on the role of zinc toxicity in causes of copper deficiency, changes in the immune system and alterations in blood lipids. As the numerous challenges presented by the study of zinc in human nutrition are met, more appropriate recommendations for dietary and therapeutic zinc intake are being made.

  8. Zinc supplementation in burn patients.

    Science.gov (United States)

    Caldis-Coutris, Nancy; Gawaziuk, Justin P; Logsetty, Sarvesh

    2012-01-01

    Micronutrient supplementation is a common practice throughout many burn centers across North America; however, uncertainty pertaining to dose, duration, and side effects of such supplements persists. The authors prospectively collected data from 23 hospitalized patients with burn sizes ranging from 10 to 93% TBSA. Each patient received a daily multivitamin and mineral supplement, 50 mg zinc (Zn) daily, and 500 mg vitamin C twice daily. Supplements were administered orally or enterally. Albumin, prealbumin, C-reactive protein, serum Zn, and serum copper were measured weekly during hospital admission until levels were within normal reference range. Our study concluded that 50 mg daily dose of Zn resulted in normal serum levels in 19 of 23 patients at discharge; 50 mg Zn supplementation did not interfere with serum copper levels; and Zn supplements, regardless of administration route, did not result in gastrointestinal side effects.

  9. Thermally induced microstrain broadening in hexagonal zinc

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, Andrew C [Los Alamos National Laboratory; Valdez, James A [Los Alamos National Laboratory; Roberts, Joyce A [Los Alamos National Laboratory; Leineweber, Andreas [STUTTGART, GERMANY; Mittemeijer, E J [STUTTGART, GERMANY; Kreher, W [DRESDEN UNIV

    2008-01-01

    Neutron powder-diffraction experiments on polycrystalline hexagonal zinc show considerable temperature-dependent line broadening. Whereas as-received zinc at 300 K exhibits narrow reflections, during cooling to a minimum temperature of 10K considerable line-broadening appears, which largely disappears again during reheating. The line broadening may be ascribed to microstrains induced by thermal microstresses due to the anisotropy of the thermal expansion (shrinkage) of hexagonal zinc. Differences between the thermal microstrains and theoretical predictions considering elastic deformation of the grains can be explained by plastic deformation and surface effects.

  10. Zinc and biotin deficiencies after pancreaticoduodenectomy.

    Science.gov (United States)

    Yazbeck, N; Muwakkit, S; Abboud, M; Saab, R

    2010-01-01

    We report zinc and biotin deficiencies after pancreaticoduodenectomy in a 16 year old female presenting clinically with marked alopecia, total body hair loss, dry skin with scales, and maculopathy with significant vision loss. These micronutrient deficiencies likely occurred due to resection of the duodenum and proximal jejunum, sites of primary absorption of several micronutrients and their protein carriers, including zinc and biotin. Early diagnosis is essential to prevent irreversible sequelae. Adequate supplementation of zinc and biotin as well as dietary advice is needed for clinical improvement.

  11. Zinc Deficiency in Humans and its Amelioration

    OpenAIRE

    Yashbir Singh Shivay

    2015-01-01

    Zinc (Zn) deficiency in humans has recently received considerable attention. Global mortality in children under 5 years of age in 2004 due to Zn deficiency was estimated at 4,53,207 as against 6,66,771 for vitamin A deficiency; 20,854 for iron deficiency and 3,619 for iodine deficiency. In humans 2800-3000 proteins contain Zn prosthetic group and Zn is an integral component of zinc finger prints that regulate DNA transcription. Zinc is a Type-2 nutrient, which means that its concentration in ...

  12. Zinc therapy for different causes of diarrhea

    OpenAIRE

    Hafaz Zakky Abdillah; Supriatmo; Melda Deliana; Selvi Nafianti; Atan Baas Sinuhaji

    2013-01-01

    Background The incidence of diarrhea in Indonesia has declined in the past five years. In spite of the increasing number of studies on the treatment for acute diarrhea, especially the use of zinc, it is not known if bacterial vs. non-bacterial etiology makes a difference in the reduction of severity of acute diarrhea in children on zinc therapy. Objective To assess the effect of zinc therapy in reducing the severity of acute bacterial and non-bacterial diarrhea. Methods We performed a...

  13. Matrix metalloproteinases in neural development: a phylogenetically diverse perspective

    Science.gov (United States)

    Small, Christopher D.; Crawford, Bryan D.

    2016-01-01

    The matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases originally characterized as secreted proteases responsible for degrading extracellular matrix proteins. Their canonical role in matrix remodelling is of significant importance in neural development and regeneration, but emerging roles for MMPs, especially in signal transduction pathways, are also of obvious importance in a neural context. Misregulation of MMP activity is a hallmark of many neuropathologies, and members of every branch of the MMP family have been implicated in aspects of neural development and disease. However, while extraordinary research efforts have been made to elucidate the molecular mechanisms involving MMPs, methodological constraints and complexities of the research models have impeded progress. Here we discuss the current state of our understanding of the roles of MMPs in neural development using recent examples and advocate a phylogenetically diverse approach to MMP research as a means to both circumvent the challenges associated with specific model organisms, and to provide a broader evolutionary context from which to synthesize an understanding of the underlying biology. PMID:27127457

  14. Matrix metalloproteinases in neural development:a phylogenetically diverse perspective

    Institute of Scientific and Technical Information of China (English)

    Christopher D. Small; Bryan D. Crawford

    2016-01-01

    The matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases originally charac-terized as secreted proteases responsible for degrading extracellular matrix proteins. Their canonical role in matrix remodelling is of signiifcant importance in neural development and regeneration, but emerging roles for MMPs, especially in signal transduction pathways, are also of obvious importance in a neural con-text. Misregulation of MMP activity is a hallmark of many neuropathologies, and members of every branch of the MMP family have been implicated in aspects of neural development and disease. However, while extraordinary research efforts have been made to elucidate the molecular mechanisms involving MMPs, methodological constraints and complexities of the research models have impeded progress. Here we discuss the current state of our understanding of the roles of MMPs in neural development using recent ex-amples and advocate a phylogenetically diverse approach to MMP research as a means to both circumvent the challenges associated with speciifc model organisms, and to provide a broader evolutionary context from which to synthesize an understanding of the underlying biology.

  15. First Principles Investigation of Zinc-anode Dissolution in Zinc-air Batteries

    OpenAIRE

    Siahrostami, Samira; Tripkovic, Vladimir; Lundgård, Keld Troen; Jensen, Kristian E.; Hansen, Heine A.; Hummelshøj, Jens Strabo; Mýrdal, Jón Steinar Garðarsson; Vegge, Tejs; Nørskov, Jens K.; Rossmeisl, Jan

    2013-01-01

    With surging interest in high energy density batteries, much attention has recently been devoted to metal-air batteries. The zinc-air battery has been known for more than hundred years and is commercially available as a primary battery, but recharging has remained elusive; in part because the fundamental mechanisms still remain to be fully understood. Here, we present a density functional theory investigation of the zinc dissolution (oxidation) on the anode side in the zinc-air battery. Two m...

  16. Effects of zinc transporters on Cryptococcus gattii virulence

    OpenAIRE

    Schneider, Rafael de Oliveira; Diehl, Camila; dos Santos, Francine Melise; Piffer, Alícia Corbellini; Garcia, Ane Wichine Acosta; Kulmann, Marcos Iuri Roos; Schrank, Augusto; Kmetzsch, Lívia; Vainstein, Marilene Henning; Staats, Charley C.

    2015-01-01

    Zinc is an essential nutrient for all living organisms because it is a co-factor of several important proteins. Furthermore, zinc may play an essential role in the infectiousness of microorganisms. Previously, we determined that functional zinc metabolism is associated with Cryptococcus gattii virulence. Here, we characterized the ZIP zinc transporters in this human pathogen. Transcriptional profiling revealed that zinc levels regulated the expression of the ZIP1, ZIP2 and ZIP3 genes, althoug...

  17. 神经管畸形孕母18~30周羊水叶酸、同型半胱氨酸、锌浓度变化分析%Analysing the changing rules of amniotic fluid folic acid,homocysteine and zinc in neural tube defects at 18-30 pregnant weeks

    Institute of Scientific and Technical Information of China (English)

    张翀; 赵翠生; 王红洲; 邱伟涛; 贺锐

    2013-01-01

    目的 通过比较神经管畸形孕母与正常妊娠孕母18~30孕周羊水叶酸、同型半胱氨酸(Hcy)及锌浓度的差异,探讨孕中晚期羊水叶酸、Hcy及锌水平与神经管畸形发生的关系.方法 对184例健康孕妇和60例孕神经管畸形胎儿孕妇18~30孕周羊水进行叶酸、Hcy和锌浓度测定.结果 正常妊娠18~30孕周羊水叶酸浓度与孕周呈正相关关系,r=0.253,P=0.036;羊水Hcy及锌浓度与孕周呈负相关关系,相关性分别为r=-0.282,P=0.024;r=-0.260,P=0.031.神经管畸形孕妇羊水叶酸、Hcy及锌与孕周之间无明显相关关系,P>0.05.神经管畸形组孕妇羊水叶酸、Hcy浓度[中位数(四分位间距)]分别为11.34(8.45)ng/mL和5.75(9.47)μmol/mL,健康孕妇羊水叶酸、Hcy浓度分别为16.85(6.43)ng/mL和3.50(2.37)μmol/L,两组间差异有统计学意义,P0.05.The differences is statistically significant between Neural tube defect group and nomal pregnant women in amniotic fluid folic acid and Hcy concentrations,P<0.05.Conclusion There were lower folic acid concertration and higher homocysteine lever in neural tube defect pregnancy than normal pregnancy.

  18. Neural networks in seismic discrimination

    Energy Technology Data Exchange (ETDEWEB)

    Dowla, F.U.

    1995-01-01

    Neural networks are powerful and elegant computational tools that can be used in the analysis of geophysical signals. At Lawrence Livermore National Laboratory, we have developed neural networks to solve problems in seismic discrimination, event classification, and seismic and hydrodynamic yield estimation. Other researchers have used neural networks for seismic phase identification. We are currently developing neural networks to estimate depths of seismic events using regional seismograms. In this paper different types of network architecture and representation techniques are discussed. We address the important problem of designing neural networks with good generalization capabilities. Examples of neural networks for treaty verification applications are also described.

  19. Associations between Dietary Iron and Zinc Intakes, and between Biochemical Iron and Zinc Status in Women

    Directory of Open Access Journals (Sweden)

    Karen Lim

    2015-04-01

    Full Text Available Iron and zinc are found in similar foods and absorption of both may be affected by food compounds, thus biochemical iron and zinc status may be related. This cross-sectional study aimed to: (1 describe dietary intakes and biochemical status of iron and zinc; (2 investigate associations between dietary iron and zinc intakes; and (3 investigate associations between biochemical iron and zinc status in a sample of premenopausal women aged 18–50 years who were recruited in Melbourne and Sydney, Australia. Usual dietary intakes were assessed using a 154-item food frequency questionnaire (n = 379. Iron status was assessed using serum ferritin and hemoglobin, zinc status using serum zinc (standardized to 08:00 collection, and presence of infection/inflammation using C-reactive protein (n = 326. Associations were explored using multiple regression and logistic regression. Mean (SD iron and zinc intakes were 10.5 (3.5 mg/day and 9.3 (3.8 mg/day, respectively. Median (interquartile range serum ferritin was 22 (12–38 μg/L and mean serum zinc concentrations (SD were 12.6 (1.7 μmol/L in fasting samples and 11.8 (2.0 μmol/L in nonfasting samples. For each 1 mg/day increase in dietary iron intake, zinc intake increased by 0.4 mg/day. Each 1 μmol/L increase in serum zinc corresponded to a 6% increase in serum ferritin, however women with low serum zinc concentration (AM fasting < 10.7 μmol/L; AM nonfasting < 10.1 μmol/L were not at increased risk of depleted iron stores (serum ferritin <15 μg/L; p = 0.340. Positive associations were observed between dietary iron and zinc intakes, and between iron and zinc status, however interpreting serum ferritin concentrations was not a useful proxy for estimating the likelihood of low serum zinc concentrations and women with depleted iron stores were not at increased risk of impaired zinc status in this cohort.

  20. Measurement of Zinc Absorption From Meals: Comparison of Extrinsi Zinc Labeling and Independent Measurements of Dietary Zinc Absorption

    Science.gov (United States)

    Sheng, Xiao-Yang; Hambidge, K. Michael; Miller, Leland V.; Westcott, Jamie E.; Lei, Sian; Krebs, Nancy F.

    2017-01-01

    Background Extrinsic labeling techniques are typically used to measure fractional absorption of zinc (FAZextrinsic) but none have been adequately evaluated. Objective To compare determination of the quantity of zinc absorbed (TAZextrinsic) using measurements of FAZextrinsic with results of simultaneous determinations of dietary zinc absorbed (TAZmetabolic) that are not dependent on labeling ingested food with an extrinsic tracer (modified metabolic balance technique). Design 70Zn was administered orally with all meals for 6 consecutive days to 21 healthy, free-living adult women consuming a constant diet. 68Zn and 67Zn were administered intravenously. FAZextrinsic was measured using a dual isotope tracer ratio technique and multiplied by dietary zinc to give TAZextrinsic TAZmetabolic was determined by addition of net absorption of zinc and endogenous fecal zinc, the latter determined by an isotope dilution technique. Results TAZextrinsic and TAZmetabolic were 3.0 ± 1.1mg/day and 3.1 ± 1.1 mg/day respectively, paired t-test p = 0.492. The correlation coefficient for TAZextrinsic and TAZmetabolic was 0.91, and for FAZextrinsic and FAZmetabolic was 0.95. A Bland Altman analysis indicated a bias of 0.07, and the limits of agreement of −0.86 to 1.01 for TAZextrinsic and TAZmatabolic Conclusion These results from two independent methods provide reasonable validation of our extrinsic labeling technique for a wide range of composite diets. PMID:20209474

  1. Decreased astroglial cell adhesion and proliferation on zinc oxide nanoparticle polyurethane composites

    Directory of Open Access Journals (Sweden)

    Justin T Seil

    2008-11-01

    Full Text Available Justin T Seil, Thomas J WebsterLaboratory for Nanomedicine Research, Division of Engineering, Brown University, Providence, RI, USAAbstract: Nanomaterials offer a number of properties that are of interest to the field of neural tissue engineering. Specifically, materials that exhibit nanoscale surface dimensions have been shown to promote neuron function while simultaneously minimizing the activity of cells such as astrocytes that inhibit central nervous system regeneration. Studies demonstrating enhanced neural tissue regeneration in electrical fields through the use of conductive materials have led to interest in piezoelectric materials (or those materials which generate a transient electrical potential when mechanically deformed such as zinc oxide (ZnO. It has been speculated that ZnO nanoparticles possess increased piezoelectric properties over ZnO micron particles. Due to this promise in neural applications, the objective of the present in vitro study was, for the first time, to assess the activity of astroglial cells on ZnO nanoparticle polymer composites. ZnO nanoparticles embedded in polyurethane were analyzed via scanning electron microscopy to evaluate nanoscale surface features of the composites. The surface chemistry was characterized via X-ray photoelectron spectroscopy. Astroglial cell response was evaluated based on cell adhesion and proliferation. Astrocyte adhesion was significantly reduced on ZnO nanoparticle/polyurethane (PU composites with a weight ratio of 50:50 (PU:ZnO wt.%, 75:25 (PU:ZnO wt.%, and 90:10 (PU:ZnO wt.% in comparison to pure PU. The successful production of ZnO nanoparticle composite scaffolds suitable for decreasing astroglial cell density demonstrates their potential as a nerve guidance channel material with greater efficiency than what may be available today.Keywords: zinc oxide, nanoparticles, astrocytes, neural tissue, nervous system, biomaterials

  2. Zinc and its importance for human health: An integrative review.

    Science.gov (United States)

    Roohani, Nazanin; Hurrell, Richard; Kelishadi, Roya; Schulin, Rainer

    2013-02-01

    Since its first discovery in an Iranian male in 1961, zinc deficiency in humans is now known to be an important malnutrition problem world-wide. It is more prevalent in areas of high cereal and low animal food consumption. The diet may not necessarily be low in zinc, but its bio-availability plays a major role in its absorption. Phytic acid is the main known inhibitor of zinc. Compared to adults, infants, children, adolescents, pregnant, and lactating women have increased requirements for zinc and thus, are at increased risk of zinc depletion. Zinc deficiency during growth periods results in growth failure. Epidermal, gastrointestinal, central nervous, immune, skeletal, and reproductive systems are the organs most affected clinically by zinc deficiency. Clinical diagnosis of marginal Zn deficiency in humans remains problematic. So far, blood plasma/serum zinc concentration, dietary intake, and stunting prevalence are the best known indicators of zinc deficiency. Four main intervention strategies for combating zinc deficiency include dietary modification/diversification, supplementation, fortification, and bio-fortification. The choice of each method depends on the availability of resources, technical feasibility, target group, and social acceptance. In this paper, we provide a review on zinc biochemical and physiological functions, metabolism including, absorption, excretion, and homeostasis, zinc bio-availability (inhibitors and enhancers), human requirement, groups at high-risk, consequences and causes of zinc deficiency, evaluation of zinc status, and prevention strategies of zinc deficiency.

  3. Zinc and its importance for human health: An integrative review

    Directory of Open Access Journals (Sweden)

    Nazanin Roohani

    2013-01-01

    Full Text Available Since its first discovery in an Iranian male in 1961, zinc deficiency in humans is now known to be an important malnutrition problem world-wide. It is more prevalent in areas of high cereal and low animal food consumption. The diet may not necessarily be low in zinc, but its bio-availability plays a major role in its absorption. Phytic acid is the main known inhibitor of zinc. Compared to adults, infants, children, adolescents, pregnant, and lactating women have increased requirements for zinc and thus, are at increased risk of zinc depletion. Zinc deficiency during growth periods results in growth failure. Epidermal, gastrointestinal, central nervous, immune, skeletal, and reproductive systems are the organs most affected clinically by zinc deficiency. Clinical diagnosis of marginal Zn deficiency in humans remains problematic. So far, blood plasma/serum zinc concentration, dietary intake, and stunting prevalence are the best known indicators of zinc deficiency. Four main intervention strategies for combating zinc deficiency include dietary modification/diversification, supplementation, fortification, and bio-fortification. The choice of each method depends on the availability of resources, technical feasibility, target group, and social acceptance. In this paper, we provide a review on zinc biochemical and physiological functions, metabolism including, absorption, excretion, and homeostasis, zinc bio-availability (inhibitors and enhancers, human requirement, groups at high-risk, consequences and causes of zinc deficiency, evaluation of zinc status, and prevention strategies of zinc deficiency.

  4. Zinc-induced protection against cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Early, J.L.; Schnell, R.C.

    1978-02-01

    Pretreatment of male rats with cadmium acetate potentiates the duration of hexobarbital hypnosis and inhibits the rate of hepatic microsomal drug metabolism. Pretreatment of rats with zinc acetate protects against these alterations in drug action elicited by cadmium.

  5. Model of how plants sense zinc deficiency

    DEFF Research Database (Denmark)

    Assuncao, Ana G.L.; Persson, Daniel Olof; Husted, Søren;

    2013-01-01

    to develop plant-based solutions addressing nutrient-use-efficiency and adaptation to nutrient-limited or -toxic soils. Recently two transcription factors of the bZIP family (basic-region leucine zipper) have been identified in Arabidopsis and shown to be pivotal in the adaptation response to zinc deficiency....... They represent not only the first regulators of zinc homeostasis identified in plants, but also a very promising starting-point that can provide new insights into the molecular basis of how plants sense and adapt to the stress of zinc deficiency. Considering the available information thus far we propose...... in this review a putative model of how plants sense zinc deficiency....

  6. Controlling fires in silver/zinc batteries

    Science.gov (United States)

    Boshers, W. A.; Britz, W. A.

    1977-01-01

    Silver/zinc storage battery fires are often difficult to extinguish. Improved technique employs manifold connected to central evacuation chamber to rapidly vent combustion-supporting gases generated by battery plate oxides.

  7. Sealed Cylindrical Silver/Zinc Batteries Project

    Data.gov (United States)

    National Aeronautics and Space Administration — RBC Technologies has significanly improved the cycle life and wet life of silver/zinc battery technology through novel separator and anode formulations. This...

  8. The Nuts and Bolts of Zinc-Nickel: OEM Zinc Nickel Implementation on Fasteners - Getting It Into Production

    Science.gov (United States)

    2014-11-01

    Blake Simpson Louie Tran The Nuts and Bolts of Zinc- Nickel OEM Zinc Nickel Implementation on Fasteners – Getting It Into Production Report...REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE The Nuts and Bolts of Zinc- Nickel : OEM Zinc Nickel Implementation on...currently in production 2. Problem at Hand – Hexavalent Chromates 3. Transition to Zinc- Nickel 4. Preliminary Testing 5. Plan moving forward for

  9. Rule Extraction:Using Neural Networks or for Neural Networks?

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hua Zhou

    2004-01-01

    In the research of rule extraction from neural networks, fidelity describes how well the rules mimic the behavior of a neural network while accuracy describes how well the rules can be generalized. This paper identifies the fidelity-accuracy dilemma. It argues to distinguish rule extraction using neural networks and rule extraction for neural networks according to their different goals, where fidelity and accuracy should be excluded from the rule quality evaluation framework, respectively.

  10. Zinc coordination spheres in protein structures.

    Science.gov (United States)

    Laitaoja, Mikko; Valjakka, Jarkko; Jänis, Janne

    2013-10-07

    Zinc metalloproteins are one of the most abundant and structurally diverse proteins in nature. In these proteins, the Zn(II) ion possesses a multifunctional role as it stabilizes the fold of small zinc fingers, catalyzes essential reactions in enzymes of all six classes, or assists in the formation of biological oligomers. Previously, a number of database surveys have been conducted on zinc proteins to gain broader insights into their rich coordination chemistry. However, many of these surveys suffer from severe flaws and misinterpretations or are otherwise limited. To provide a more comprehensive, up-to-date picture on zinc coordination environments in proteins, zinc containing protein structures deposited in the Protein Data Bank (PDB) were analyzed in detail. A statistical analysis in terms of zinc coordinating amino acids, metal-to-ligand bond lengths, coordination number, and structural classification was performed, revealing coordination spheres from classical tetrahedral cysteine/histidine binding sites to more complex binuclear sites with carboxylated lysine residues. According to the results, coordination spheres of hundreds of crystal structures in the PDB could be misinterpreted due to symmetry-related molecules or missing electron densities for ligands. The analysis also revealed increasing average metal-to-ligand bond length as a function of crystallographic resolution, which should be taken into account when interrogating metal ion binding sites. Moreover, one-third of the zinc ions present in crystal structures are artifacts, merely aiding crystal formation and packing with no biological significance. Our analysis provides solid evidence that a minimal stable zinc coordination sphere is made up by four ligands and adopts a tetrahedral coordination geometry.

  11. Fuzzy Multiresolution Neural Networks

    Science.gov (United States)

    Ying, Li; Qigang, Shang; Na, Lei

    A fuzzy multi-resolution neural network (FMRANN) based on particle swarm algorithm is proposed to approximate arbitrary nonlinear function. The active function of the FMRANN consists of not only the wavelet functions, but also the scaling functions, whose translation parameters and dilation parameters are adjustable. A set of fuzzy rules are involved in the FMRANN. Each rule either corresponding to a subset consists of scaling functions, or corresponding to a sub-wavelet neural network consists of wavelets with same dilation parameters. Incorporating the time-frequency localization and multi-resolution properties of wavelets with the ability of self-learning of fuzzy neural network, the approximation ability of FMRANN can be remarkable improved. A particle swarm algorithm is adopted to learn the translation and dilation parameters of the wavelets and adjusting the shape of membership functions. Simulation examples are presented to validate the effectiveness of FMRANN.

  12. Zinc and zinc transporters in macrophages and their roles in efferocytosis in COPD.

    Directory of Open Access Journals (Sweden)

    Rhys Hamon

    Full Text Available Our previous studies have shown that nutritional zinc restriction exacerbates airway inflammation accompanied by an increase in caspase-3 activation and an accumulation of apoptotic epithelial cells in the bronchioles of the mice. Normally, apoptotic cells are rapidly cleared by macrophage efferocytosis, limiting any secondary necrosis and inflammation. We therefore hypothesized that zinc deficiency is not only pro-apoptotic but also impairs macrophage efferocytosis. Impaired efferocytic clearance of apoptotic epithelial cells by alveolar macrophages occurs in chronic obstructive pulmonary disease (COPD, cigarette-smoking and other lung inflammatory diseases. We now show that zinc is a factor in impaired macrophage efferocytosis in COPD. Concentrations of zinc were significantly reduced in the supernatant of bronchoalveolar lavage fluid of patients with COPD who were current smokers, compared to healthy controls, smokers or COPD patients not actively smoking. Lavage zinc was positively correlated with AM efferocytosis and there was decreased efferocytosis in macrophages depleted of Zn in vitro by treatment with the membrane-permeable zinc chelator TPEN. Organ and cell Zn homeostasis are mediated by two families of membrane ZIP and ZnT proteins. Macrophages of mice null for ZIP1 had significantly lower intracellular zinc and efferocytosis capability, suggesting ZIP1 may play an important role. We investigated further using the human THP-1 derived macrophage cell line, with and without zinc chelation by TPEN to mimic zinc deficiency. There was no change in ZIP1 mRNA levels by TPEN but a significant 3-fold increase in expression of another influx transporter ZIP2, consistent with a role for ZIP2 in maintaining macrophage Zn levels. Both ZIP1 and ZIP2 proteins were localized to the plasma membrane and cytoplasm in normal human lung alveolar macrophages. We propose that zinc homeostasis in macrophages involves the coordinated action of ZIP1 and ZIP2

  13. Introduction to Artificial Neural Networks

    DEFF Research Database (Denmark)

    Larsen, Jan

    1999-01-01

    The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks.......The note addresses introduction to signal analysis and classification based on artificial feed-forward neural networks....

  14. Involvement of XZFP36L1,an RNA-binding protein,in Xenopus neural development%Involvement of XZFP36L1, an RNA-binding protein,in Xenopus neural development

    Institute of Scientific and Technical Information of China (English)

    Yingjie XIA; Shuhua ZHAO; Bingyu MAO

    2012-01-01

    Xenopus ZFP36L1 (zinc finger protein 36,C3H type-like 1) belongs to the ZFP36 family of RNA-binding proteins,which contains two characteristic tandem CCCH-type zinc-finger domains.The ZFP36 proteins can bind AU-rich elements in 3' untranslated regions of target mRNAs and promote their turnover.However,the expression and role of ZFP36 genes during neural development in Xenopus embryos remains largely tmknown.The present study showed that Xenopus ZFP36L1 was expressed at the dorsal part of the forebrain,forebrain-midbrain boundary,and midbrain-hindbrain boundary from late neurula stages to tadpole stages of embryonic development.Overexpression of XZFP36L1 in Xenopus embryos inhibited neural induction and differentiation,leading to severe neural tube defects.The function of XZP36L1 requires both its zinc finger and C terminal domains,which also affect its subcellular localization.These results suggest that XZFP36L1 is likely involved in neural development in Xenopus and might play an important role in post-transcriptional regulation.

  15. Chelation of hippocampal zinc enhances long-term potentiation and synaptic tagging/capture in CA1 pyramidal neurons of aged rats: implications to aging and memory.

    Science.gov (United States)

    Shetty, Mahesh Shivarama; Sharma, Mahima; Sajikumar, Sreedharan

    2017-02-01

    Aging is associated with decline in cognitive functions, prominently in the memory consolidation and association capabilities. Hippocampus plays a crucial role in the formation and maintenance of long-term associative memories, and a significant body of evidence shows that impairments in hippocampal function correlate with aging-related memory loss. A number of studies have implicated alterations in hippocampal synaptic plasticity, such as long-term potentiation (LTP), in age-related cognitive decline although exact mechanisms underlying are not completely clear. Zinc deficiency and the resultant adverse effects on cognition have been well studied. However, the role of excess of zinc in synaptic plasticity, especially in aging, is not addressed well. Here, we have investigated the hippocampal zinc levels and the impairments in synaptic plasticity, such as LTP and synaptic tagging and capture (STC), in the CA1 region of acute hippocampal slices from 82- to 84-week-old male Wistar rats. We report increased zinc levels in the hippocampus of aged rats and also deficits in the tetani-induced and dopaminergic agonist-induced late-LTP and STC. The observed deficits in synaptic plasticity were restored upon chelation of zinc using a cell-permeable chelator. These data suggest that functional plasticity and associativity can be successfully established in aged neural networks by chelating zinc with cell-permeable chelating agents.

  16. Relationship between gastric levels and antiulcerogenic activity of zinc.

    Science.gov (United States)

    Navarro, C; Ramis, A; Sendrós, S; Bulbena, O; Ferrer, L; Escolar, G

    1990-01-01

    The relationship between the absorption of an organic zinc salt, zinc acexamate, and its antiulcerogenic activity in a model of cold-restraint stress was studied. Serum and gastric levels of zinc, as well as its antiulcerogenic effect, were determined after oral or intravenous administration of zinc acexamate. Cytochemical and X-ray microanalysis techniques were also applied. In the rats subjected to cold-restraint stress, gastric levels of zinc correlated with the antiulcerogenic effect observed after administration of zinc acexamate. However, it was not possible to establish a relationship between serum levels and the pharmacologic effect of zinc. Our results in animals subjected to regular diet indicate that the antiulcerogenic effect exhibited by zinc compounds could be associated with the presence of zinc at different levels of gastric tissue.

  17. Zinc and Regulation of Inflammatory Cytokines: Implications for Cardiometabolic Disease

    Directory of Open Access Journals (Sweden)

    Samir Samman

    2012-07-01

    Full Text Available In atherosclerosis and diabetes mellitus, the concomitant presence of low-grade systemic inflammation and mild zinc deficiency highlights a role for zinc nutrition in the management of chronic disease. This review aims to evaluate the literature that reports on the interactions of zinc and cytokines. In humans, inflammatory cytokines have been shown both to up- and down-regulate the expression of specific cellular zinc transporters in response to an increased demand for zinc in inflammatory conditions. The acute phase response includes a rapid decline in the plasma zinc concentration as a result of the redistribution of zinc into cellular compartments. Zinc deficiency influences the generation of cytokines, including IL-1β, IL-2, IL-6, and TNF-α, and in response to zinc supplementation plasma cytokines exhibit a dose-dependent response. The mechanism of action may reflect the ability of zinc to either induce or inhibit the activation of NF-κB. Confounders in understanding the zinc-cytokine relationship on the basis of in vitro experimentation include methodological issues such as the cell type and the means of activating cells in culture. Impaired zinc homeostasis and chronic inflammation feature prominently in a number of cardiometabolic diseases. Given the high prevalence of zinc deficiency and chronic disease globally, the interplay of zinc and inflammation warrants further examination.

  18. Serum and semen zinc levels in normozoospermic and oligozoospermic men

    Energy Technology Data Exchange (ETDEWEB)

    Madding, C.I.; Jacob, M.; Ramsay, V.P.; Sokol, R.Z.

    1986-01-01

    We studied 11 unselected men who presented to a Reproductive Endocrinology Clinic with histories of infertility and low sperm counts. Reproductive hormones and semen und serum zinc levels were measured. All men had semen analyses performed on at least three separate occasions. A similar set of laboratory evaluations were performed on 11 other men who had normal semen analyses and no history of infertility. No abnormalities of reproductive hormones were found in either group. Mean serum zinc levels were significantly lower in the infertile men. Mean semen zinc levels were not significantly different. There was no correlation between serum and semen zinc levels in either group. A significant correlation was found between sperm count and semen zinc in the volunteers with normal counts, but not in the oligozoospermic men. The results obtained in this study suggest that lowered serum zinc is more common than formerly appreciated in unselected patients with infertility. The high level of zinc found in semen is due primarily to the secretions of the prostate gland and reflects prostatic stores. Serum zinc is thought to be a reasonable indicator of zinc status. The lack of correlation between serum zinc and semen zinc found in our study suggests that mild zinc deficiency may lower serum zinc while the larger prostatic zinc stores remain unaffected.

  19. Generalized Adaptive Artificial Neural Networks

    Science.gov (United States)

    Tawel, Raoul

    1993-01-01

    Mathematical model of supervised learning by artificial neural network provides for simultaneous adjustments of both temperatures of neurons and synaptic weights, and includes feedback as well as feedforward synaptic connections. Extension of mathematical model described in "Adaptive Neurons For Artificial Neural Networks" (NPO-17803). Dynamics of neural network represented in new model by less-restrictive continuous formalism.

  20. Bioavailability of zinc in Wistar rats fed with rice fortified with zinc oxide.

    Science.gov (United States)

    Della Lucia, Ceres Mattos; Santos, Laura Luiza Menezes; Rodrigues, Kellen Cristina da Cruz; Rodrigues, Vivian Cristina da Cruz; Martino, Hércia Stampini Duarte; Sant'Ana, Helena Maria Pinheiro

    2014-06-13

    The study of zinc bioavailability in foods is important because this mineral intake does not meet the recommended doses for some population groups. Also, the presence of dietary factors that reduce zinc absorption contributes to its deficiency. Rice fortified with micronutrients (Ultra Rice®) is a viable alternative for fortification since this cereal is already inserted into the population habit. The aim of this study was to evaluate the bioavailability of zinc (Zn) in rice fortified with zinc oxide. During 42 days, rats were divided into four groups and fed with diets containing two different sources of Zn (test diet: UR® fortified with zinc oxide, or control diet: zinc carbonate (ZnCO3)), supplying 50% or 100%, respectively, of the recommendations of this mineral for animals. Weight gain, food intake, feed efficiency ratio, weight, thickness and length of femur; retention of zinc, calcium (Ca) and magnesium (Mg) in the femur and the concentrations of Zn in femur, plasma and erythrocytes were evaluated. Control diet showed higher weight gain, feed efficiency ratio, retention of Zn and Zn concentration in the femur (p 0.05) for dietary intake, length and thickness of the femur, erythrocyte and plasmatic Zn between groups. Although rice fortified with zinc oxide showed a lower bioavailability compared to ZnCO3, this food can be a viable alternative to be used as a vehicle for fortification.

  1. Effect of zinc from zinc sulfate on trace mineral concentrations of milk in Varamini ewes

    NARCIS (Netherlands)

    Zali, A.; Ganjkhanlou, M.

    2009-01-01

    This study was conducted to evaluate the effect of feeding supplemental zinc (zinc sulfate) in different levels (15, 30, or 45 mg/kg) on trace mineral concentrations in milk of ewes. Thirty lactating Varaminni ewes were assigned to three experimental groups according to their live body weights, milk

  2. Enhanced zinc consumption causes memory deficits and increased brain levels of zinc

    Science.gov (United States)

    Flinn, J.M.; Hunter, D.; Linkous, D.H.; Lanzirotti, A.; Smith, L.N.; Brightwell, J.; Jones, B.F.

    2005-01-01

    Zinc deficiency has been shown to impair cognitive functioning, but little work has been done on the effects of elevated zinc. This research examined the effect on memory of raising Sprague-Dawley rats on enhanced levels of zinc (10 ppm ZnCO3; 0.153 mM) in the drinking water for periods of 3 or 9 months, both pre- and postnatally. Controls were raised on lab water. Memory was tested in a series of Morris Water Maze (MWM) experiments, and zinc-treated rats were found to have impairments in both reference and working memory. They were significantly slower to find a stationary platform and showed greater thigmotaxicity, a measure of anxiety. On a working memory task, where the platform was moved each day, zinc-treated animals had longer latencies over both trials and days, swam further from the platform, and showed greater thigmotaxicity. On trials using an Atlantis platform, which remained in one place but was lowered on probe trials, the zinc-treated animals had significantly fewer platform crossings, spent less time in the target quadrant, and did not swim as close to the platform position. They had significantly greater latency on nonprobe trials. Microprobe synchrotron X-ray fluorescence (??SXRF) confirmed that brain zinc levels were increased by adding ZnCO 3 to the drinking water. These data show that long-term dietary administration of zinc can lead to impairments in cognitive function. ?? 2004 Elsevier Inc. All rights reserved.

  3. Microwave Synthesis of Zinc Hydroxy Sulfate Nanoplates and Zinc Oxide Nanorods in the Classroom

    Science.gov (United States)

    Dziedzic, Rafal M.; Gillian-Daniel, Anne Lynn; Peterson, Greta M.; Martínez-Herna´ndez, Kermin J.

    2014-01-01

    In this hands-on, inquiry-based lab, high school and undergraduate students learn about nanotechnology by synthesizing their own nanoparticles in a single class period. This simple synthesis of zinc oxide nanorods and zinc hydroxy sulfate nanoplates can be done in 15 min using a household microwave oven. Reagent concentration, reaction…

  4. Growth of zinc oxide nanostructures

    Indian Academy of Sciences (India)

    K Sreenivas; Sanjeev Kumar; Jaya Choudhury; Vinay Gupta

    2005-11-01

    Zinc oxide (ZnO) nanowhiskers have been prepared using a multilayer ZnO(50 nm)/Zn(20 nm)/ZnO(2 m) structure on a polished stainless steel (SS) substrate by high rate magnetron sputtering. The formation of uniformly distributed ZnO nanowhiskers with about 20 nm dia. and 2 to 5 m length was observed after a post-deposition annealing of the prepared structure at 300–400 ° C. An array of highly -axis oriented ZnO columns (70–300 nm in dia. and up to 10 m long) were grown on Si substrates by pulsed laser deposition (PLD) at a high pressure (1 Torr), and Raman studies showed the activation of surface phonon modes. The nanosized powder (15–20 nm) and nanoparticle ZnO films on glass substrate were also prepared by a chemical route. Nanowhiskers showed enhanced UV light detection characteristics, and the chemically prepared ZnO nanoparticle films exhibited good sensing properties for alcohol.

  5. A new zinc binding fold underlines the versatility of zinc binding modules in protein evolution.

    Science.gov (United States)

    Sharpe, Belinda K; Matthews, Jacqueline M; Kwan, Ann H Y; Newton, Anthea; Gell, David A; Crossley, Merlin; Mackay, Joel P

    2002-05-01

    Many different zinc binding modules have been identified. Their abundance and variety suggests that the formation of zinc binding folds might be relatively common. We have determined the structure of CH1(1), a 27-residue peptide derived from the first cysteine/histidine-rich region (CH1) of CREB binding protein (CBP). This peptide forms a highly ordered zinc-dependent fold that is distinct from known folds. The structure differs from a subsequently determined structure of a larger region from the CH3 region of CBP, and the CH1(1) fold probably represents a nonphysiologically active form. Despite this, the fold is thermostable and tolerant to both multiple alanine mutations and changes in the zinc-ligand spacing. Our data support the idea that zinc binding domains may arise frequently. Additionally, such structures may prove useful as scaffolds for protein design, given their stability and robustness.

  6. Neural Network Ensembles

    DEFF Research Database (Denmark)

    Hansen, Lars Kai; Salamon, Peter

    1990-01-01

    We propose several means for improving the performance an training of neural networks for classification. We use crossvalidation as a tool for optimizing network parameters and architecture. We show further that the remaining generalization error can be reduced by invoking ensembles of similar...

  7. Zinc, copper and selenium in reproduction.

    Science.gov (United States)

    Bedwal, R S; Bahuguna, A

    1994-07-15

    Of the nine biological trace elements, zinc, copper and selenium are important in reproduction in males and females. Zinc content is high in the adult testis, and the prostate has a higher concentration of zinc than any other organ of the body. Zinc deficiency first impairs angiotensin converting enzyme (ACE) activity, and this in turn leads to depletion of testosterone and inhibition of spermatogenesis. Defects in spermatozoa are frequently observed in the zinc-deficient rat. Zinc is thought to help to extend the functional life span of the ejaculated spermatozoa. Zinc deficiency in the female can lead to such problems as impaired synthesis/secretion of (FSH) and (LH), abnormal ovarian development, disruption of the estrous cycle, frequent abortion, a prolonged gestation period, teratogenicity, stillbirths, difficulty in parturition, pre-eclampsia, toxemia and low birth weights of infants. The level of testosterone in the male has been suggested to play a role in the severity of copper deficiency. Copper-deficient female rats are protected against mortality due to copper deficiency, and the protection has been suggested to be provided by estrogens, since estrogens alter the subcellular distribution of copper in the liver and increase plasma copper levels by inducing ceruloplasmin synthesis. The selenium content of male gonads increases during pubertal maturation. Selenium is localized in the mitochondrial capsule protein (MCP) of the midpiece. Maximal incorporation in MCP occurs at steps 7 and 12 of spermatogenesis and uptake decreases by step 15. Selenium deficiency in females results in infertility, abortions and retention of the placenta. The newborns from a selenium-deficient mother suffer from muscular weakness, but the concentration of selenium during pregnancy does not have any effect on the weight of the baby or length of pregnancy. The selenium requirements of a pregnant and lactating mother are increased as a result of selenium transport to the fetus via

  8. Zinc Fortification Decreases ZIP1 Gene Expression of Some Adolescent Females with Appropriate Plasma Zinc Levels

    Directory of Open Access Journals (Sweden)

    Rosa O. Méndez

    2014-06-01

    Full Text Available Zinc homeostasis is achieved after intake variation by changes in the expression levels of zinc transporters. The aim of this study was to evaluate dietary intake (by 24-h recall, absorption, plasma zinc (by absorption spectrophotometry and the expression levels (by quantitative PCR, of the transporters ZIP1 (zinc importer and ZnT1 (zinc exporter in peripheral white blood cells from 24 adolescent girls before and after drinking zinc-fortified milk for 27 day. Zinc intake increased (p < 0.001 from 10.5 ± 3.9 mg/day to 17.6 ± 4.4 mg/day, and its estimated absorption from 3.1 ± 1.2 to 5.3 ± 1.3 mg/day. Mean plasma zinc concentration remained unchanged (p > 0.05 near 150 µg/dL, but increased by 31 µg/dL (p < 0.05 for 6/24 adolescents (group A and decreased by 25 µg/dL (p < 0.05 for other 6/24 adolescents (group B. Expression of ZIP1 in blood leukocytes was reduced 1.4-fold (p < 0.006 in group A, while for the expression of ZnT1 there was no difference after intervention (p = 0.39. An increase of dietary zinc after 27-days consumption of fortified-milk did not increase (p > 0.05 the plasma level of adolescent girls but for 6/24 participants from group A in spite of the formerly appropriation, which cellular zinc uptake decreased as assessed by reduction of the expression of ZIP1.

  9. Effect of low zinc intake on absorption and excretion of zinc by infants studied with 70Zn as extrinsic tag.

    Science.gov (United States)

    Ziegler, E E; Serfass, R E; Nelson, S E; Figueroa-Colón, R; Edwards, B B; Houk, R S; Thompson, J J

    1989-11-01

    The effect of low dietary intake of zinc was studied in six normal infants with the use of 70Zn as an extrinsic tag. Of the two study formulas, one provided a zinc intake similar to that of customary infant formulas ("high" intake), whereas the other provided a "low" zinc intake. Two zinc absorption studies were performed with each formula (sequence: high-low-low-high). Extrinsically labeled formula was fed for 24 h and excreta were collected for 72 h. Zinc isotope ratios were determined by inductively coupled plasma mass spectrometry (ICP/MS). When zinc intake was high, net zinc absorption was 9.1 +/- 8.7% (mean +/- SD) of intake and net zinc retention was 74 +/- 91 micrograms/(kg.d). True zinc (70Zn) absorption was 16.8 +/- 5.8% of intake and fecal excretion of endogenous zinc was 78 +/- 56 micrograms/(kg.d). When zinc intake was low, net absorption of zinc increased significantly (P less than 0.001) to 26.0 +/- 13.0% of intake, but net retention was not significantly different at 42 +/- 33 micrograms/(kg.d). True absorption of zinc also increased significantly (P less than 0.001) to 41.1 +/- 7.8% of intake, whereas fecal endogenous zinc decreased (P less than 0.05) to 34 +/- 16 micrograms/(kg.d) during low zinc intake. Thus, infants maintain zinc balance in the face of low zinc intake through increased efficiency of absorption and decreased excretion of endogenous zinc.

  10. Apoptosis may underlie the pathology of zinc-deficient skin.

    Science.gov (United States)

    Wilson, Dallas; Varigos, George; Ackland, M Leigh

    2006-02-01

    The trace element zinc is essential for the survival and function of all cells. Zinc deficiency, whether nutritional or genetic, is fatal if left untreated. The effects of zinc deficiency are particularly obvious in the skin, seen as an erythematous rash, scaly plaques, and ulcers. Electron microscopy reveals degenerative changes within keratinocytes. Despite the well-documented association between zinc deficiency and skin pathology, it is not clear which cellular processes are most sensitive to zinc deficiency and could account for the typical pathological features. We used the cultured HaCaT keratinocyte line to obtain insight into the cellular effects of zinc deficiency, as these cells show many characteristics of normal skin keratinocytes. Zinc deficiency was induced by growing cells in the presence of the zinc chelator, TPEN, or by growth in zinc-deficient medium. Growth of cells in zinc-deficient medium resulted in a 44% reduction of intracellular zinc levels and a 75% reduction in the activity of the zinc-dependent enzyme, 5'-nucleotidase, relative to the control cells. Over a period of 7 days of exposure to zinc-deficient conditions, no changes in cell viability and growth, or in the cytoskeletal and cell adhesion systems, were found in HaCaT cells. At 7 days, however, induction of apoptosis was indicated by the presence of DNA fragmentation and expression of active caspase-3 in cells. These results demonstrate that apoptosis is the earliest detectable cellular change induced by zinc deficiency in HaCaT keratinocytes. Our observations account for many of the features of zinc deficiency, including the presence of degenerate nuclei, chromatin aggregates and abnormal organization of keratin, that may represent the later stages of apoptosis. In summary, a major causal role for apoptosis in the pathology of zinc deficiency in the skin is proposed. This role is consistent with the previously unexplained diverse range of degenerative cellular changes seen at the

  11. Mechanisms of mammalian zinc-regulated gene expression.

    Science.gov (United States)

    Jackson, Kelly A; Valentine, Ruth A; Coneyworth, Lisa J; Mathers, John C; Ford, Dianne

    2008-12-01

    Mechanisms through which gene expression is regulated by zinc are central to cellular zinc homoeostasis. In this context, evidence for the involvement of zinc dyshomoeostasis in the aetiology of diseases, including Type 2 diabetes, Alzheimer's disease and cancer, highlights the importance of zinc-regulated gene expression. Mechanisms elucidated in bacteria and yeast provide examples of different possible modes of zinc-sensitive gene regulation, involving the zinc-regulated binding of transcriptional activators and repressors to gene promoter regions. A mammalian transcriptional regulatory mechanism that mediates zinc-induced transcriptional up-regulation, involving the transcription factor MTF1 (metal-response element-binding transcription factor 1), has been studied extensively. Gene responses in the opposite direction (reduced mRNA levels in response to increased zinc availability) have been observed in mammalian cells, but a specific transcriptional regulatory process responsible for such a response has yet to be identified. Examples of single zinc-sensitive transcription factors regulating gene expression in opposite directions are emerging. Although zinc-induced transcriptional repression by MTF1 is a possible explanation in some specific instances, such a mechanism cannot account for repression by zinc of all mammalian genes that show this mode of regulation, indicating the existence of as yet uncharacterized mechanisms of zinc-regulated transcription in mammalian cells. In addition, recent findings reveal a role for effects of zinc on mRNA stability in the regulation of specific zinc transporters. Our studies on the regulation of the human gene SLC30A5 (solute carrier 30A5), which codes for the zinc transporter ZnT5, have revealed that this gene provides a model system by which to study both zinc-induced transcriptional down-regulation and zinc-regulated mRNA stabilization.

  12. Role of nutritional zinc in the prevention of osteoporosis.

    Science.gov (United States)

    Yamaguchi, Masayoshi

    2010-05-01

    Zinc is known as an essential nutritional factor in the growth of the human and animals. Bone growth retardation is a common finding in various conditions associated with dietary zinc deficiency. Bone zinc content has been shown to decrease in aging, skeletal unloading, and postmenopausal conditions, suggesting its role in bone disorder. Zinc has been demonstrated to have a stimulatory effect on osteoblastic bone formation and mineralization; the metal directly activates aminoacyl-tRNA synthetase, a rate-limiting enzyme at translational process of protein synthesis, in the cells, and it stimulates cellular protein synthesis. Zinc has been shown to stimulate gene expression of the transcription factors runt-related transcription factor 2 (Runx2) that is related to differentiation into osteoblastic cells. Moreover, zinc has been shown to inhibit osteoclastic bone resorption due to inhibiting osteoclast-like cell formation from bone marrow cells and stimulating apoptotic cell death of mature osteoclasts. Zinc has a suppressive effect on the receptor activator of nuclear factor (NF)-kappaB ligand (RANKL)-induced osteoclastogenesis. Zinc transporter has been shown to express in osteoblastic and osteoclastic cells. Zinc protein is involved in transcription. The intake of dietary zinc causes an increase in bone mass. beta-Alanyl-L: -histidinato zinc (AHZ) is a zinc compound, in which zinc is chelated to beta-alanyl-L: -histidine. The stimulatory effect of AHZ on bone formation is more intensive than that of zinc sulfate. Zinc acexamate has also been shown to have a potent-anabolic effect on bone. The oral administration of AHZ or zinc acexamate has the restorative effect on bone loss under various pathophysiologic conditions including aging, skeletal unloading, aluminum bone toxicity, calcium- and vitamin D-deficiency, adjuvant arthritis, estrogen deficiency, diabetes, and fracture healing. Zinc compounds may be designed as new supplementation factor in the prevention and

  13. Different Zinc Sources Have Diverse Impacts on Gene Expression of Zinc Absorption Related Transporters in Intestinal Porcine Epithelial Cells.

    Science.gov (United States)

    Huang, Danping; Zhuo, Zhao; Fang, Shenglin; Yue, Min; Feng, Jie

    2016-10-01

    This study was conducted to investigate the effects of zinc sources on gene expression of zinc-related transporters in intestinal porcine epithelial cells (IPEC-1). IPEC-1 cells were treated with zinc glycine chelate (Zn-Gly), zinc methionine (Zn-Met), and zinc sulfate (ZnSO4), respectively, for measurement of cell viability. Then, the relative expression of zinc-related transporters in IPEC-1 in response to different zinc sources (50 μmol/L zinc) was measured. Zinc transporter SLC39A4 (ZIP4) expression was selectively silenced to assess the function of ZIP4 in inorganic and organic zinc absorption. The result showed that Zn-Gly and Zn-Met had lower cell damage compared with ZnSO4 on the same zinc levels. Different zinc sources improved the expression of metallothionein1 (MT1) and zinc transporter SLC30A1 (ZnT1) messenger RNA (mRNA) compared with the control (P zinc addition. MT1 and ZnT1 mRNA expressions in Zn-Gly and Zn-Met were higher than those in ZnSO4, and ZIP4 mRNA expression in Zn-Met was the lowest among three kinds of zinc sources (P zinc sources groups. Silencing of ZIP4 significantly decreased MT1 mRNA expression in ZnSO4 and Zn-Gly treatments, reduced zinc absorption rate, and increased DMT1 mRNA expression in ZnSO4 compared with negative control. In summary, different zinc sources could improve zinc status on IPEC-1 cells and organic zinc had lower cell damage compared with ZnSO4. Moreover, Zn-Gly and Zn-Met are more efficient on zinc absorption according to the expression of various zinc-related transporters MT1, ZIP4, ZnT1, and DMT1. ZIP4 played a direct role in inorganic zinc uptake, and the absorption of zinc in Zn-Gly depends on ZIP4 partly, while absorption of Zn-Met is less dependent on ZIP4.

  14. New chromate-free passivation treatments for zinc, zinc alloy, and zinc-containing coatings and surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C. J. E.; King, J. E.; Wright, D. G.; Erricker, S. L.; Wilcox, G.; Treacy, G.; Hovestad, A.; Woodhead, T.; Buckland, J.; Lindsey, L.; Eruli, M.; Koelewijn, H.; Shropshire, I. [Defence Evaluation and Research Agency, Farnborough, Hampshire (United Kingdom)

    2001-07-01

    Results of a series of experiments to develop chromate-free treatments which provide the same level of corrosion protection and promote adhesion of surface coatings and paint films are discussed. The initial phase of the project identified two different treatments which prompted the investigation of pH, temperature and immersion time, as part of the effort to optimize the processes. When subjected to accelerated corrosion tests, one of the two processes (the PTA process) compared favourably with conventional chromate filming when applied to electrodeposited zinc-nickel coatings. Further investigation revealed that the process also works effectively on brass and nickel substrates and provides an appropriate substrate for the application of lacquer. Development of an effective treatment for zinc coatings, particularly hot dip galvanized zinc, is in progress. This paper discusses the results of toxicological and environmental studies conducted in conjunction with the two processes and reviews lessons learned and opportunities for exploiting the findings. 5 refs., 6 tabs.

  15. Antioxidant role of zinc in diabetes mellitus.

    Science.gov (United States)

    Cruz, Kyria Jayanne Clímaco; de Oliveira, Ana Raquel Soares; Marreiro, Dilina do Nascimento

    2015-03-15

    Chronic hyperglycemia statue noticed in diabetes mellitus favors the manifestation of oxidative stress by increasing the production of reactive oxygen species and/or by reducing the antioxidant defense system activity. Zinc plays an important role in antioxidant defense in type 2 diabetic patients by notably acting as a cofactor of the superoxide dismutase enzyme, by modulating the glutathione metabolism and metallothionein expression, by competing with iron and copper in the cell membrane and by inhibiting nicotinamide adenine dinucleotide phosphate-oxidase enzyme. Zinc also improves the oxidative stress in these patients by reducing chronic hyperglycemia. It indeed promotes phosphorylation of insulin receptors by enhancing transport of glucose into cells. However, several studies reveal changes in zinc metabolism in individuals with type 2 diabetes mellitus and controversies remain regarding the effect of zinc supplementation in the improvement of oxidative stress in these patients. Faced with the serious challenge of the metabolic disorders related to oxidative stress in diabetes along with the importance of antioxidant nutrients in the control of this disease, new studies may contribute to improve our understanding of the role played by zinc against oxidative stress and its connection with type 2 diabetes mellitus prognosis. This could serve as a prelude to the development of prevention strategies and treatment of disorders associated with this chronic disease.

  16. Zinc Leaching from Tire Crumb Rubber

    Science.gov (United States)

    Rhodes, E. P.; Ren, J.; Mays, D. C.

    2010-12-01

    Recent estimates indicate that more than 2 billion scrap tires are currently stockpiled in the United States and approximately 280 million more tires are added annually. Various engineering applications utilize recycled tires in the form of shredded tire crumb rubber. However, the use of tire crumb rubber may have negative environmental impacts, especially when the rubber comes into contact with water. A review of the literature indicates that leaching of zinc from tire crumb rubber is the most significant water quality concern associated with using this material. Zinc is generally used in tire manufacturing, representing approximately 1.3% of the final product by mass. This study will report results from the U.S. Environmental Protection Agency’s (EPA’s) Synthetic Precipitation Leaching Procedure, batch leaching tests, and column leaching tests performed to quantify the process by which zinc leaches from tire crumb rubber into water. Results are interpreted with a first-order kinetic attachment/detachment model, implemented with the U.S. Agricultural Research Service software HYDRUS-1D, in order to determine the circumstances when zinc leaching from tire crumb rubber would be expected to comply with the applicable discharge limits. One potential application for recycled tires is replacing sand with tire crumb rubber in granular media filters used for stormwater pollution control. For this to be a viable application, the total zinc in the stormwater discharge must be below the EPA’s benchmark value of 0.117 mg/L.

  17. Intraprostatic injection of neutralized zinc in rats

    Energy Technology Data Exchange (ETDEWEB)

    Fahim, M.S.; Wang, M.; Sutcu, M.F.; Fahim, Z.; Safron, J.A.; Ganjam, V.K. (Univ. of Missouri, Columbia (United States) Xian Medical University (China))

    1991-03-11

    Zinc has been implicated in steroid endocrinology of the prostate gland. The conversion of testosterone to dihydrotestosterone (DHT) by 5{alpha}-reductase enzyme is believed to express androgenic responses in the prostate. To note the effect of neutralized zinc on the prostate, 50 sexually mature rats, weighing 325 {plus minus} 20 grams, were divided into 5 groups as follows: (1) control, (2) sham, (3) castrated, (4) injected intraprostatically with 10 mg. neutralized zinc, and (5) injected intraprostatically with 20 mg. neutralized zinc. Results in the treated groups indicated significant reduction of prostate weights, 12% and 53% and histologically normal prostate; no significant change in weight and histological structure of testes, epididymides, and seminal vesicles; significant reduction in 5{alpha}-reductase activity and total protein and DNA concentrations in prostate tissue; and no significant effect on progeny of treated animals. These results suggest that direct application of neutralized zinc to the prostate offers a new modality for treatment of prostatitis without affecting spermatogenesis and testosterone production.

  18. Stunting prevalence, plasma zinc concentrations, and dietary zinc intakes in a nationally representative sample suggest a high risk of zinc deficiency among women and young children in Cameroon.

    Science.gov (United States)

    Engle-Stone, Reina; Ndjebayi, Alex O; Nankap, Martin; Killilea, David W; Brown, Kenneth H

    2014-03-01

    Before initiating a mass zinc fortification program, this study assessed the prevalence of and risk factors for low zinc status among Cameroonian women and children. In a nationally representative survey, we randomly selected 30 clusters in each of 3 strata (North, South, and Yaoundé/Douala) and 10 households per cluster, each with a woman aged 15-49 y and a child aged 12-59 mo (n = 1002 households). Twenty-four-hour dietary recalls (with duplicates in a subset) and anthropometric measurements were conducted, and non-fasting blood was collected to measure plasma zinc concentration (PZC) and markers of inflammation. PZC was adjusted for methodologic factors (time of collection and processing, and presence of inflammation). The prevalence of stunting was 33% (32% South; 46% North; 13% Yaoundé/Douala). Among women, 82% had low adjusted PZC (Nutrition Consultative Group (IZiNCG), 29 and 41% of women had inadequate zinc intakes, assuming moderate and low bioavailability, respectively, but only 8% of children had inadequate zinc intake. Depending on the estimated physiologic zinc requirement applied, 17% (IZiNCG) and 92% (Institute of Medicine) of women had inadequate absorbable zinc intakes. Total zinc intakes were greatest in the North region, possibly because of different dietary patterns in this area. Zinc deficiency is a public health problem among women and children in Cameroon, although PZC and dietary zinc yield different estimates of the prevalence of deficiency. Large-scale programs to improve zinc nutrition, including food fortification, are needed.

  19. Relative Penetration of Zinc Oxide and Zinc Ions into Human Skin after Application of Different Zinc Oxide Formulations.

    Science.gov (United States)

    Holmes, Amy M; Song, Zhen; Moghimi, Hamid R; Roberts, Michael S

    2016-02-23

    Zinc oxide (ZnO) is frequently used in commercial sunscreen formulations to deliver their broad range of UV protection properties. Concern has been raised about the extent to which these ZnO particles (both micronized and nanoparticulate) penetrate the skin and their resultant toxicity. This work has explored the human epidermal skin penetration of zinc oxide and its labile zinc ion dissolution product that may potentially be formed after application of ZnO nanoparticles to human epidermis. Three ZnO nanoparticle formulations were used: a suspension in the oil, capric caprylic triglycerides (CCT), the base formulation commonly used in commercially available sunscreen products; an aqueous ZnO suspension at pH 6, similar to the natural skin surface pH; and an aqueous ZnO suspension at pH 9, a pH at which ZnO is stable and there is minimal pH-induced impairment of epidermal integrity. In each case, the ZnO in the formulations did not penetrate into the intact viable epidermis for any of the formulations but was associated with an enhanced increase in zinc ion fluorescence signal in both the stratum corneum and the viable epidermis. The highest labile zinc fluorescence was found for the ZnO suspension at pH 6. It is concluded that, while topically applied ZnO does not penetrate into the viable epidermis, these applications are associated with hydrolysis of ZnO on the skin surface, leading to an increase in zinc ion levels in the stratum corneum, thence in the viable epidermis and subsequently in the systemic circulation and the urine.

  20. Neural dynamics based on the recognition of neural fingerprints

    Directory of Open Access Journals (Sweden)

    José Luis eCarrillo-Medina

    2015-03-01

    Full Text Available Experimental evidence has revealed the existence of characteristic spiking features in different neural signals, e.g. individual neural signatures identifying the emitter or functional signatures characterizing specific tasks. These neural fingerprints may play a critical role in neural information processing, since they allow receptors to discriminate or contextualize incoming stimuli. This could be a powerful strategy for neural systems that greatly enhances the encoding and processing capacity of these networks. Nevertheless, the study of information processing based on the identification of specific neural fingerprints has attracted little attention. In this work, we study (i the emerging collective dynamics of a network of neurons that communicate with each other by exchange of neural fingerprints and (ii the influence of the network topology on the self-organizing properties within the network. Complex collective dynamics emerge in the network in the presence of stimuli. Predefined inputs, i.e. specific neural fingerprints, are detected and encoded into coexisting patterns of activity that propagate throughout the network with different spatial organization. The patterns evoked by a stimulus can survive after the stimulation is over, which provides memory mechanisms to the network. The results presented in this paper suggest that neural information processing based on neural fingerprints can be a plausible, flexible and powerful strategy.

  1. The changes of zinc transporter ZnT gene expression in response to zinc supplementation in obese women.

    Science.gov (United States)

    Noh, Hwayoung; Paik, Hee Young; Kim, Jihye; Chung, Jayong

    2014-12-01

    Obesity is associated with an alteration in zinc metabolism. This alteration may be associated with changes in gene expression of zinc transporters. In this study, we examined the leukocyte expression of zinc transporter ZnTs in response to zinc supplementation in young obese women. Thirty-five young obese women (BMI ≥ 25 kg/m(2)), aged 18-28 years, were randomly assigned to two groups: a placebo group or a zinc group (30 mg zinc/day for 8 weeks). Usual dietary zinc intake was estimated from 3-day diet records. Serum zinc and urinary zinc concentrations were measured by atomic absorption spectrometry. Messenger RNA (mRNA) levels of leukocyte ZnT transporters were examined using quantitative real-time PCR. Expression levels of two ZnT transporters, ZnT1 and ZnT5, in obese women, increased significantly after zinc supplementation. At the end of the study, mRNA levels of ZnT1 and ZnT5 showed no correlation with serum zinc or urinary zinc concentration in obese women. In addition, a further study was conducted to identify whether the association between the gene expression levels of leukocyte ZnT1 and ZnT5 and dietary zinc intake remained consistent in 216 healthy young adults aged 20-29 years. A positive correlation between ZnT1 and dietary zinc intake (r = 0.181, P = 0.089) was also observed in healthy men although the significance was marginal. Taken together, these results show that the gene expression levels of ZnT1 and ZnT5 may be changed by zinc intake, suggesting that zinc supplementation could potentially restore ZnT transporter expression in obese women with altered zinc metabolism.

  2. Genetic causes and gene–nutrient interactions in mammalian zinc deficiencies: acrodermatitis enteropathica and transient neonatal zinc deficiency as examples.

    Science.gov (United States)

    Kasana, Shakhenabat; Din, Jamila; Maret, Wolfgang

    2015-01-01

    Discovering genetic causes of zinc deficiency has been a remarkable scientific journey. It started with the description of a rare skin disease, its treatment with various agents, the successful therapy with zinc, and the identification of mutations in a zinc transporter causing the disease. The journey continues with defining the molecular and cellular pathways that lead to the symptoms caused by zinc deficiency. Remarkably, at least two zinc transporters from separate protein families are now known to be involved in the genetics of zinc deficiency. One is ZIP4, which is involved in intestinal zinc uptake. Its mutations can cause acrodermatitis enteropathica (AE) with autosomal recessive inheritance. The other one is ZnT2, the transporter responsible for supplying human milk with zinc. Mutations in this transporter cause transient neonatal zinc deficiency (TNZD) with symptoms similar to AE but with autosomal dominant inheritance. The two diseases can be distinguished in affected infants. AE is fatal if zinc is not supplied to the infant after weaning, whereas TNZD is a genetic defect of the mother limiting the supply of zinc in the milk, and therefore the infant usually will obtain enough zinc once weaned. Although these diseases are relatively rare, the full functional consequences of the numerous mutations in ZIP4 and ZnT2 and their interactions with dietary zinc are not known. In particular, it remains unexplored whether some mutations cause milder disease phenotypes or increase the risk for other diseases if dietary zinc requirements are not met or exceeded. Thus, it is not known whether widespread zinc deficiency in human populations is based primarily on a nutritional deficiency or determined by genetic factors as well. This consideration becomes even more significant with regard to mutations in the other 22 human zinc transporters, where associations with a range of diseases, including diabetes, heart disease, and mental illnesses have been observed

  3. Properties of Zip4 accumulation during zinc deficiency and its usefulness to evaluate zinc status: a study of the effects of zinc deficiency during lactation.

    Science.gov (United States)

    Hashimoto, Ayako; Nakagawa, Miki; Tsujimura, Natsuki; Miyazaki, Shiho; Kizu, Kumiko; Goto, Tomoko; Komatsu, Yusuke; Matsunaga, Ayu; Shirakawa, Hitoshi; Narita, Hiroshi; Kambe, Taiho; Komai, Michio

    2016-03-01

    Systemic and cellular zinc homeostasis is elaborately controlled by ZIP and ZnT zinc transporters. Therefore, detailed characterization of their expression properties is of importance. Of these transporter proteins, Zip4 functions as the primarily important transporter to control systemic zinc homeostasis because of its indispensable function of zinc absorption in the small intestine. In this study, we closely investigated Zip4 protein accumulation in the rat small intestine in response to zinc status using an anti-Zip4 monoclonal antibody that we generated and contrasted this with the zinc-responsive activity of the membrane-bound alkaline phosphatase (ALP). We found that Zip4 accumulation is more rapid in response to zinc deficiency than previously thought. Accumulation increased in the jejunum as early as 1 day following a zinc-deficient diet. In the small intestine, Zip4 protein expression was higher in the jejunum than in the duodenum and was accompanied by reduction of ALP activity, suggesting that the jejunum can become zinc deficient more easily. Furthermore, by monitoring Zip4 accumulation levels and ALP activity in the duodenum and jejunum, we reasserted that zinc deficiency during lactation may transiently alter plasma glucose levels in the offspring in a sex-specific manner, without affecting homeostatic control of zinc metabolism. This confirms that zinc nutrition during lactation is extremely important for the health of the offspring. These results reveal that rapid Zip4 accumulation provides a significant conceptual advance in understanding the molecular basis of systemic zinc homeostatic control, and that properties of Zip4 protein accumulation are useful to evaluate zinc status closely.

  4. The Zinc Transport Systems and Their Regulation in Pathogenic Fungi.

    Science.gov (United States)

    Jung, Won Hee

    2015-09-01

    Zinc is an essential micronutrient required for many enzymes that play essential roles in a cell. It was estimated that approximately 3% of the total cellular proteins are required for zinc for their functions. Zinc has long been considered as one of the key players in host-pathogen interactions. The host sequesters intracellular zinc by utilizing multiple cellular zinc importers and exporters as a means of nutritional immunity. To overcome extreme zinc limitation within the host environment, pathogenic microbes have successfully evolved a number of mechanisms to secure sufficient concentrations of zinc for their survival and pathogenesis. In this review, we briefly discuss the zinc uptake systems and their regulation in the model fungus Saccharomyces cerevisiae and in major human pathogenic fungi such as Aspergillus fumigatus, Candida albicans, and Cryptococcus gattii.

  5. The immune system and the impact of zinc during aging

    Directory of Open Access Journals (Sweden)

    Haase Hajo

    2009-06-01

    Full Text Available Abstract The trace element zinc is essential for the immune system, and zinc deficiency affects multiple aspects of innate and adaptive immunity. There are remarkable parallels in the immunological changes during aging and zinc deficiency, including a reduction in the activity of the thymus and thymic hormones, a shift of the T helper cell balance toward T helper type 2 cells, decreased response to vaccination, and impaired functions of innate immune cells. Many studies confirm a decline of zinc levels with age. Most of these studies do not classify the majority of elderly as zinc deficient, but even marginal zinc deprivation can affect immune function. Consequently, oral zinc supplementation demonstrates the potential to improve immunity and efficiently downregulates chronic inflammatory responses in the elderly. These data indicate that a wide prevalence of marginal zinc deficiency in elderly people may contribute to immunosenescence.

  6. Oral zinc and common childhood infections--An update.

    Science.gov (United States)

    Basnet, Sudha; Mathisen, Maria; Strand, Tor A

    2015-01-01

    Zinc is an essential micronutrient important for growth and for normal function of the immune system. Many children in developing countries have inadequate zinc nutrition. Routine zinc supplementation reduces the risk of respiratory infections and diarrhea, the two leading causes of morbidity and mortality in young children worldwide. In childhood diarrhea oral zinc also reduces illness duration and risk of persistent episodes. Oral zinc is therefore recommended for the treatment of acute diarrhea in young children. The results from the studies that have measured the therapeutic effect of zinc on acute respiratory infections, however, are conflicting. Moreover, the results of therapeutic zinc for childhood malaria also are so far not promising.This paper gives a brief outline of the current evidence from clinical trials on therapeutic effect of oral zinc on childhood respiratory infections, pneumonia and malaria and also of new evidence of the effect on serious bacterial illness in young infants.

  7. Fabrications of zinc-releasing biocement combining zinc calcium phosphate to calcium phosphate cement.

    Science.gov (United States)

    Horiuchi, Shinya; Hiasa, Masahiro; Yasue, Akihiro; Sekine, Kazumitsu; Hamada, Kenichi; Asaoka, Kenzo; Tanaka, Eiji

    2014-01-01

    Recently, zinc-releasing bioceramics have been the focus of much attention owing to their bone-forming ability. Thus, some types of zinc-containing calcium phosphate (e.g., zinc-doped tricalcium phosphate and zinc-substituted hydroxyapatite) are examined and their osteoblastic cell responses determined. In this investigation, we studied the effects of zinc calcium phosphate (ZCP) derived from zinc phosphate incorporated into calcium phosphate cement (CPC) in terms of its setting reaction and MC3T3-E1 osteoblast-like cell responses. Compositional analysis by powder X-ray diffraction analysis revealed that HAP crystals were precipitated in the CPC containing 10 or 30wt% ZCP after successfully hardening. However, the crystal growth observed by scanning electron microscopy was delayed in the presence of additional ZCP. These findings indicate that the additional zinc inhibits crystal growth and the conversion of CPC to the HAP crystals. The proliferation of the cells and alkaline phosphatase (ALP) activity were enhanced when 10wt% ZCP was added to CPC. Taken together, ZCP added CPC at an appropriate fraction has a potent promotional effect on bone substitute biomaterials.

  8. Selective extraction of zinc from sulfate leach solution of zinc ore

    Institute of Scientific and Technical Information of China (English)

    覃文庆; 蓝卓越; 黎维中; 邱冠周

    2003-01-01

    Selective extraction of zinc from sulfate leach solution of zinc ore was studied.D2EHPA dissolved in260# kerosene was used as extractant.The pH-extraction isotherms show the extraction order of D2EHPA for metals is Fe3+>Zn2+>Ca2+>Al3+>Mn2+>Cu2+>Cd2+>Co2+>Ni2+>Mg2+(pH0.5).This confirms that Fe3+ ispreferentially extracted before the extraction of zinc.Extraction experiments were carried out with varying the extractant content,equilibration time,aqueous pH and phase ratio,and the solvent extraction of zinc with sodium saltof D2EHPA were also investigated.Some impurity co-extracted into the zinc loaded organic phase was efficiently removed by scrub,and the Fe3+ was hardly stripped from organic phase by sulfuric acid,hence zinc was separatedfrom Fe3+ by selective stripping.A pregnant zinc sulfate solution with low contaminants was obtained by selectivesolvent extraction.

  9. Nutritional assessment methods for zinc supplementation in prepubertal non-zinc-deficient children

    Directory of Open Access Journals (Sweden)

    Márcia Marília Gomes Dantas Lopes

    2015-10-01

    Full Text Available Background: Zinc is an essential nutrient that is required for numerous metabolic functions, and zinc deficiency results in growth retardation, cell-mediated immune dysfunction, and cognitive impairment. Objective: This study evaluated nutritional assessment methods for zinc supplementation in prepubertal non-zinc-deficient children. Design: We performed a randomised, controlled, triple-blind study. The children were divided into a control group (10% sorbitol, n=31 and an experimental group (10 mg Zn/day, n=31 for 3 months. Anthropometric and dietary assessments as well as bioelectrical measurements were performed in all children. Results: Our study showed (1 an increased body mass index for age and an increased phase angle in the experimental group; (2 a positive correlation between nutritional assessment parameters in both groups; (3 increased soft tissue, and mainly fat-free mass, in the body composition of the experimental group, as determined using bioelectrical impedance vector analysis; (4 increased consumption of all nutrients, including zinc, in the experimental group; and (5 an increased serum zinc concentration in both groups (p<0.0001. Conclusions: Given that a reference for body composition analysis does not exist for intervention studies, longitudinal studies are needed to investigate vector migration during zinc supplementation. These results reinforce the importance of employing multiple techniques to assess the nutritional status of populations.

  10. Anti-ulcer activity of a slow-release zinc complex, zinc monoglycerolate (Glyzinc).

    Science.gov (United States)

    Rainsford, K D; Whitehouse, M W

    1992-06-01

    A slow-release zinc complex, zinc monoglycerolate (ZMG) was examined for its potential gastroprotective activity in various gastric ulcer models. These models comprised (a) oral or parenteral non-steroidal anti-inflammatory drugs (NSAIDs) given to rats whose gastrointestinal mucosa was pre-sensitized by prior development of arthritis, oleyl alcohol-induced inflammation and cold exposure, (b) oral ethanol (12.5-100%) with and without added 4% HCl, (c) intraperitoneal reserpine (5 mg kg-1) in arthritic and normal rats and in normal mice, (d) oral NSAIDs given to mice in which acid and pepsin production was stimulated by co-administration of intraperitoneal bethanechol chloride (5 mg kg-1) to enhance ulcer development, and (e) NSAIDs given to carrageenan-inflamed rats to determine effects of ZMG on paw inflammation. In these models, ZMG given orally was effective in preventing development of gastric lesions, except with propionic acid NSAIDs; the effective doses being apparently dependent on the severity of the mucosal injury. In many of the models ZMG was superior to zinc sulphate and other zinc salts or metal ion complexes investigated but was slightly more effective or equipotent compared with zinc acexamate. ZMG did not impair the anti-oedemic effects of NSAIDs. ZMG is thus an effective agent in preventing ulcer development in a wide range of model systems and may be more effective than zinc salts because of the controlled slow-release of zinc from the complex.

  11. Polymorphisms of the maternal Slug gene in fetal neural tube defects in a Chinese population

    Institute of Scientific and Technical Information of China (English)

    Li Guo; Hong Zhao; Yuheng Pei; Quanren He; Wan-I Li; Ting Zhang; Xiaoying Zheng; Ran Zhou; Jun Xie

    2010-01-01

    Several studies have demonstrated that Slug,which encodes a zinc finger of the Snail family of transcription factors,is a potential risk factor for neural tube defects.Neural tube defects tend to occur with a high rate in Shanxi province,China.The present case-control study investigated genotypic distributions and allele frequencies of Slug C1548A polymorphisms in DNA samples from59 women with a history of neural tube defect pregnancies and 73 controls during the same period from Shanxi Province,China.Results demonstrated that women with a history of neural tube defect pregnancies had significantly greater genotypic distributions of Slug AA genotypes and A allele frequencies compared with controls,and A allele Slug C1548A was a risk factor for neural tube defects(odds ratio = 3.444;95% confidence interval;2.021-5.868,P < 0.05).Three-dimensional structure prediction revealed that Slug C1548A resulted in transition of aspartic acid into glutamate at position 119.This indicated that these mutations could lead to damaged protein structure and function.These findings suggest that Slug C1548A gene polymorphism is closely related to neural tube defects in a population of Han Chinese origin from Shanxi Province,China

  12. Book review: Current perspectives on zinc deposits

    Science.gov (United States)

    Kelley, Karen D.

    2016-01-01

    This book, published in 2015 by the Irish Association for Economic Geology (IAEG), is a compilation of papers and abstracts written by selected authors who attended the ZINC 2010 Conference in Cork, Ireland. Unlike most books produced each decade by the IAEG, which are focused primarily on achievements of the Irish and European mineral sectors, this book has a global perspective of a single commodity—zinc. As stated in the Preface, the theme of the conference and book was quite relevant for the IAEG because Ireland has the highest concentration of zinc per square kilometer on the planet. The book contains 7 full papers and 5 extended abstracts by keynote speakers, followed by 17 extended abstracts by other presenters, plus an Appendix (reprint) of a previously published paper.

  13. Effect of zinc on Entamoeba histolytica pathogenicity.

    Science.gov (United States)

    Vega Robledo, G B; Carrero, J C; Ortiz-Ortiz, L

    1999-06-01

    The present study analyzes the effects of zinc on Entamoeba histolytica activity and on its pathogenicity. Metal activity was evaluated in vitro with regard to the parasite's viability, replication, and adhesion to epithelial cells and in vivo with regard to its pathogenicity. The results obtained in vitro show that zinc at 1.0 mM concentration does not affect amebic viability; however, it does decrease amebic replication and adhesion (P vivo studies performed on a model of experimental liver abscess in the hamster indicate that the intraperitoneal administration of a single dose of zinc at 48 h after the intrahepatic inoculation of amebic trophozoites significantly inhibits (P vivo as manifested by inhibition of amebic pathogenicity.

  14. Zinc-induced oligomerization of zinc α2 glycoprotein reveals multiple fatty acid-binding sites.

    Science.gov (United States)

    Zahid, Henna; Miah, Layeque; Lau, Andy M; Brochard, Lea; Hati, Debolina; Bui, Tam T T; Drake, Alex F; Gor, Jayesh; Perkins, Stephen J; McDermott, Lindsay C

    2016-01-01

    Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigated. Analytical ultracentrifugation (AUC) and CD showed that zinc, but not other divalent metals, causes ZAG to oligomerize in solution. Thus ZAG dimers and trimers were observed in the presence of 1 and 2 mM zinc. Molecular modelling of X-ray scattering curves and sedimentation coefficients indicated a progressive stacking of ZAG monomers, suggesting that the ZAG groove may be occluded in these. Using fluorescence-detected sedimentation velocity, these ZAG-zinc oligomers were again observed in the presence of the fluorescent boron dipyrromethene fatty acid C16-BODIPY (4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-hexadecanoic acid). Fluorescence spectroscopy confirmed that ZAG binds C16-BODIPY. ZAG binding to C16-BODIPY, but not to DAUDA, was reduced by increased zinc concentrations. We conclude that the lipid-binding groove in ZAG contains at least two distinct fatty acid-binding sites for DAUDA and C16-BODIPY, similar to the multiple lipid binding seen in the structurally related immune protein CD1c. In addition, because high concentrations of zinc occur in the pancreas, the perturbation of these multiple lipid-binding sites by zinc may be significant in Type 2 diabetes where dysregulation of ZAG and zinc homoeostasis occurs.

  15. Nitric oxide and zinc-mediated protein assemblies involved in mu opioid receptor signaling.

    Science.gov (United States)

    Rodríguez-Muñoz, María; Garzón, Javier

    2013-12-01

    Opioids are among the most effective analgesics in controlling the perception of intense pain, although their continuous use decreases their potency due to the development of tolerance. The glutamate N-methyl-D-aspartate (NMDA) receptor system is currently considered to be the most relevant functional antagonist of morphine analgesia. In the postsynapse of different brain regions the C terminus of the mu-opioid receptor (MOR) associates with NR1 subunits of NMDARs, as well as with a series of signaling proteins, such as neural nitric oxide synthase (nNOS)/nitric oxide (NO), protein kinase C (PKC), calcium and calmodulin-dependent kinase II (CaMKII) and the mitogen-activated protein kinases (MAPKs). NO is implicated in redox signaling and PKC falls under the regulation of zinc metabolism, suggesting that these signaling elements might participate in the regulation of MOR activity by the NMDAR. In this review, we discuss the influence of redox signaling in the mechanisms whose plasticity triggers opioid tolerance. Thus, the MOR C terminus assembles a series of signaling proteins around the homodimeric histidine triad nucleotide-binding protein 1 (HINT1). The NMDAR NR1 subunit and the regulator of G protein signaling RGSZ2 bind HINT1 in a zinc-independent manner, with RGSZ2 associating with nNOS and regulating MOR-induced production of NO. This NO acts on the RGSZ2 zinc finger, providing the zinc ions that are required for PKC/Raf-1 cysteine-rich domains to simultaneously bind to the histidines present in the HINT1 homodimer. The MOR-induced activation of phospholipase β (PLCβ) regulates PKC, which increases the reactive oxygen species (ROS) by acting on NOX/NADPH, consolidating the long-term PKC activation required to regulate the Raf-1/MAPK cascade and enhancing NMDAR function. Thus, RGSZ2 serves as a Redox Zinc Switch that converts NO signals into Zinc signals, thereby modulating Redox Sensor Proteins like PKCγ and Raf-1. Accordingly, redox-dependent and

  16. Evaluating the cost-effectiveness of preventive zinc supplementation

    OpenAIRE

    Fink, Günther; Heitner, Jesse

    2014-01-01

    Background Even though the WHO currently recommends zinc for diarrhea management, no consensus has been reached with respect to routine distribution of zinc for preventive reasons. We reviewed the health impact of preventive zinc interventions, and evaluated the relative cost effectiveness of currently feasible interventions. Methods Using the latest relative risk estimates reported in the literature, we parameterized a health impact model, and calculated the expected benefits of zinc supplem...

  17. Evaluating the cost-effectiveness of preventive zinc supplementation

    OpenAIRE

    Fink, Günther; Heitner, Jesse

    2014-01-01

    Background: Even though the WHO currently recommends zinc for diarrhea management, no consensus has been reached with respect to routine distribution of zinc for preventive reasons. We reviewed the health impact of preventive zinc interventions, and evaluated the relative cost effectiveness of currently feasible interventions. Methods: Using the latest relative risk estimates reported in the literature, we parameterized a health impact model, and calculated the expected benefits of zinc suppl...

  18. Microwave-assisted additive free synthesis of nanocrystalline zinc oxide

    OpenAIRE

    Bhatte, Kushal D.; Tambade, Pawan; Fujita, Shin-ichiro; Arai, Masahiko; Bhalchandra M. Bhanage

    2010-01-01

    An additive free synthesis of nanocrystalline zinc oxide using microwave technique is reported. Current methodology is faster, cleaner and cost effective compared with conventional method for the synthesis of zinc oxide nanocrystalline materials. The structure and morphology of nanocrystalline zinc oxide was investigated by TEM, XRD, EDAX, UV-Vis spectroscopy. The results demonstrate that microwave heating can produce polygonal zinc oxide within a short span of time.

  19. Neural tube defects

    Directory of Open Access Journals (Sweden)

    M.E. Marshall

    1981-09-01

    Full Text Available Neural tube defects refer to any defect in the morphogenesis of the neural tube, the most common types being spina bifida and anencephaly. Spina bifida has been recognised in skeletons found in north-eastern Morocco and estimated to have an age of almost 12 000 years. It was also known to the ancient Greek and Arabian physicians who thought that the bony defect was due to the tumour. The term spina bifida was first used by Professor Nicolai Tulp of Amsterdam in 1652. Many other terms have been used to describe this defect, but spina bifida remains the most useful general term, as it describes the separation of the vertebral elements in the midline.

  20. Quantum Neural Networks

    CERN Document Server

    Gupta, S; Gupta, Sanjay

    2002-01-01

    This paper initiates the study of quantum computing within the constraints of using a polylogarithmic ($O(\\log^k n), k\\geq 1$) number of qubits and a polylogarithmic number of computation steps. The current research in the literature has focussed on using a polynomial number of qubits. A new mathematical model of computation called \\emph{Quantum Neural Networks (QNNs)} is defined, building on Deutsch's model of quantum computational network. The model introduces a nonlinear and irreversible gate, similar to the speculative operator defined by Abrams and Lloyd. The precise dynamics of this operator are defined and while giving examples in which nonlinear Schr\\"{o}dinger's equations are applied, we speculate on its possible implementation. The many practical problems associated with the current model of quantum computing are alleviated in the new model. It is shown that QNNs of logarithmic size and constant depth have the same computational power as threshold circuits, which are used for modeling neural network...

  1. Analysis of neural data

    CERN Document Server

    Kass, Robert E; Brown, Emery N

    2014-01-01

    Continual improvements in data collection and processing have had a huge impact on brain research, producing data sets that are often large and complicated. By emphasizing a few fundamental principles, and a handful of ubiquitous techniques, Analysis of Neural Data provides a unified treatment of analytical methods that have become essential for contemporary researchers. Throughout the book ideas are illustrated with more than 100 examples drawn from the literature, ranging from electrophysiology, to neuroimaging, to behavior. By demonstrating the commonality among various statistical approaches the authors provide the crucial tools for gaining knowledge from diverse types of data. Aimed at experimentalists with only high-school level mathematics, as well as computationally-oriented neuroscientists who have limited familiarity with statistics, Analysis of Neural Data serves as both a self-contained introduction and a reference work.

  2. Chelating ionic liquids for reversible zinc electrochemistry.

    Science.gov (United States)

    Kar, Mega; Winther-Jensen, Bjorn; Forsyth, Maria; MacFarlane, Douglas R

    2013-05-21

    Advanced, high energy-density, metal-air rechargeable batteries, such as zinc-air, are of intense international interest due to their important role in energy storage applications such as electric and hybrid vehicles, and to their ability to deal with the intermittency of renewable energy sources such as solar and wind. Ionic liquids offer a number of ideal thermal and physical properties as potential electrolytes in such large-scale energy storage applications. We describe here the synthesis and characterisation of a family of novel "chelating" ILs designed to chelate and solubilize the zinc ions to create electrolytes for this type of battery. These are based on quaternary alkoxy alkyl ammonium cations of varying oligo-ether side chains and anions such as p-toluene sulfonate, bis(trifluoromethylsulfonyl)amide and dicyanoamides. This work shows that increasing the ether chain length in the cation from two to four oxygens can increase the ionic conductivity and reduce the melting point from 67 °C to 15 °C for the tosylate system. Changing the anion also plays a significant role in the nature of the zinc deposition electrochemistry. We show that zinc can be reversibly deposited from [N(222(20201))][NTf2] and [N(222(202020201))][NTf2] beginning at -1.4 V and -1.7 V vs. SHE, respectively, but not in the case of tosylate based ILs. This indicates that the [NTf2] is a weaker coordinating anion with the zinc cation, compared to the tosylate anion, allowing the coordination of the ether chain to dominate the behavior of the deposition and stripping of zinc ions.

  3. Deficiencia de zinc y sus implicaciones funcionales

    Directory of Open Access Journals (Sweden)

    ROSADO JORGE L

    1998-01-01

    Full Text Available El presente trabajo tiene por objeto revisar los aspectos teóricos y los estudios realizados en México que sugieren la existencia de la deficiencia moderada de zinc en niños de población rural, así como algunas de las consecuencias de dicha deficiencia en la salud. El zinc es un nutrimento indispensable para el organismo de los humanos y juega un papel importante en una serie de procesos metabólicos: participa en el sitio catalítico de varios sistemas enzimáticos; participa como ion estructural en membranas biológicas, y guarda una estrecha relación con la síntesis de proteínas, entre otras cosas. Es por esto que la deficiencia de zinc está asociada con consecuencias importantes en la salud y la funcionalidad de los individuos, especialmente durante las primeras etapas de la vida. De relevancia para México es la existencia de una deficiencia moderada de zinc en los niños y las consecuencias que ésta pueda tener en la salud de los mismos. Los estudios realizados sugieren que la deficiencia moderada de zinc se presenta asociada con la ingestión de dietas basadas en alimentos de origen vegetal, las cuales contienen cantidades importantes de inhibidores de la absorción de zinc. Este tipo de dietas se consume habitualmente en las zonas rurales y en la población marginal de las ciudades en el país. Entre las consecuencias más importantes de esta deficiencia se encontró un aumento en la presencia de enfermedades infecciosas, especialmente de diarrea, y posibles alteraciones en el desarrollo de la capacidad cognoscitiva.

  4. hZIP1 zinc uptake transporter down regulation and zinc depletion in prostate cancer

    Directory of Open Access Journals (Sweden)

    Kajdacsy-Balla André

    2005-09-01

    Full Text Available Abstract Background The genetic and molecular mechanisms responsible for and associated with the development and progression of prostate malignancy are largely unidentified. The peripheral zone is the major region of the human prostate gland where malignancy develops. The normal peripheral zone glandular epithelium has the unique function of accumulating high levels of zinc. In contrast, the ability to accumulate zinc is lost in the malignant cells. The lost ability of the neoplastic epithelial cells to accumulate zinc is a consistent factor in their development of malignancy. Recent studies identified ZIP1 (SLC39A1 as an important zinc transporter involved in zinc accumulation in prostate cells. Therefore, we investigated the possibility that down-regulation of hZIP1 gene expression might be involved in the inability of malignant prostate cells to accumulate zinc. To address this issue, the expression of hZIP1 and the depletion of zinc in malignant versus non-malignant prostate glands of prostate cancer tissue sections were analyzed. hZIP1 expression was also determined in malignant prostate cell lines. Results hZIP1 gene expression, ZIP1 transporter protein, and cellular zinc were prominent in normal peripheral zone glandular epithelium and in benign hyperplastic glands (also zinc accumulating glands. In contrast, hZIP1 gene expression and transporter protein were markedly down-regulated and zinc was depleted in adenocarcinomatous glands and in prostate intra-epithelial neoplastic foci (PIN. These changes occur early in malignancy and are sustained during its progression in the peripheral zone. hZIP1 is also expressed in the malignant cell lines LNCaP, PC-3, DU-145; and in the nonmalignant cell lines HPr-1 and BPH-1. Conclusion The studies clearly establish that hZIP1 gene expression is down regulated and zinc is depleted in adenocarcinomatous glands. The fact that all the malignant cell lines express hZIP1 indicates that the down

  5. Artificial neural network modelling

    CERN Document Server

    Samarasinghe, Sandhya

    2016-01-01

    This book covers theoretical aspects as well as recent innovative applications of Artificial Neural networks (ANNs) in natural, environmental, biological, social, industrial and automated systems. It presents recent results of ANNs in modelling small, large and complex systems under three categories, namely, 1) Networks, Structure Optimisation, Robustness and Stochasticity 2) Advances in Modelling Biological and Environmental Systems and 3) Advances in Modelling Social and Economic Systems. The book aims at serving undergraduates, postgraduates and researchers in ANN computational modelling. .

  6. Compressing Convolutional Neural Networks

    OpenAIRE

    Chen, Wenlin; Wilson, James T.; Tyree, Stephen; Weinberger, Kilian Q.; Chen, Yixin

    2015-01-01

    Convolutional neural networks (CNN) are increasingly used in many areas of computer vision. They are particularly attractive because of their ability to "absorb" great quantities of labeled data through millions of parameters. However, as model sizes increase, so do the storage and memory requirements of the classifiers. We present a novel network architecture, Frequency-Sensitive Hashed Nets (FreshNets), which exploits inherent redundancy in both convolutional layers and fully-connected laye...

  7. Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Kapil Nahar

    2012-12-01

    Full Text Available An artificial neural network is an information-processing paradigm that is inspired by the way biological nervous systems, such as the brain, process information.The key element of this paradigm is the novel structure of the information processing system. It is composed of a large number of highly interconnected processing elements (neurons working in unison to solve specific problems.Ann’s, like people, learn by example.

  8. Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Kapil Nahar

    2012-12-01

    Full Text Available An artificial neural network is an information-processing paradigm that is inspired by the way biological nervous systems, such as the brain, process information. The key element of this paradigm is the novel structure of the information processing system. It is composed of a large number of highly interconnected processing elements (neurons working in unison to solve specific problems. Ann’s, like people, learn by example.

  9. Neural networks for triggering

    Energy Technology Data Exchange (ETDEWEB)

    Denby, B. (Fermi National Accelerator Lab., Batavia, IL (USA)); Campbell, M. (Michigan Univ., Ann Arbor, MI (USA)); Bedeschi, F. (Istituto Nazionale di Fisica Nucleare, Pisa (Italy)); Chriss, N.; Bowers, C. (Chicago Univ., IL (USA)); Nesti, F. (Scuola Normale Superiore, Pisa (Italy))

    1990-01-01

    Two types of neural network beauty trigger architectures, based on identification of electrons in jets and recognition of secondary vertices, have been simulated in the environment of the Fermilab CDF experiment. The efficiencies for B's and rejection of background obtained are encouraging. If hardware tests are successful, the electron identification architecture will be tested in the 1991 run of CDF. 10 refs., 5 figs., 1 tab.

  10. Coupled Neural Associative Memories

    OpenAIRE

    Karbasi, Amin; Salavati, Amir Hesam; Shokrollahi, Amin

    2013-01-01

    We propose a novel architecture to design a neural associative memory that is capable of learning a large number of patterns and recalling them later in presence of noise. It is based on dividing the neurons into local clusters and parallel plains, very similar to the architecture of the visual cortex of macaque brain. The common features of our proposed architecture with those of spatially-coupled codes enable us to show that the performance of such networks in eliminating noise is drastical...

  11. New separators for nickel-zinc batteries

    Science.gov (United States)

    Sheibley, D. W.

    1976-01-01

    Flexible separators consisting of a substrate coated with a mixture of a polymer and organic and inorganic additives were cycle tested in nickel-zinc cells. By substituting a rubber-based resin for polyphenylene oxide in the standard inorganic-organic separator, major improvements in both cell life and flexibility were made. Substituting newsprint for asbestos as the substrate shows promise for use on the zinc electrode and reduces separator cost. The importance of ample electrolyte in the cells was noted. Cycle lives and the characteristics of these flexible, low-cost separators were compared with those of a standard microporous polypropylene separator.

  12. Zinc oxide interdigitated electrode for biosensor application

    Science.gov (United States)

    Sin L., L.; Arshad, M. K. Md.; Fathil, M. F. M.; Adzhri, R.; M. Nuzaihan M., N.; Ruslinda, A. R.; Gopinath, Subash C. B.; Hashim, U.

    2016-07-01

    In biosensors, zinc oxide (ZnO) thin film plays a crucial role in term of stability, sensitivity, biocompatibility and low cost. Interdigitated electrode (IDE) design is one of the device architecture in biosensor for label free, stability and sensitivity. In this paper, we discuss the fabrication of zinc oxide deposited on the IDE as a transducer for sensing of biomolecule. The formation of APTES had increase the performance of the surface functionalization..Furthermore we extend the discuss on the surface functionalization process which is utilized for probe attachment onto the surface of biosensor through surface immobilization process, thus enables the sensing of biomolecules for biosensor application.

  13. The importance of zinc on osteoporotic bones

    Energy Technology Data Exchange (ETDEWEB)

    Lima, I.; Lopes, R.T. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear]. E-mail: ricardo@lin.ufrj.br; inaya@lin.ufrj.br; Anjos, M.J. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica]. E-mail: marcelin@lin.ufrj.br; Farias, M.L.F. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Hospital Universitario. Servico de Endocrinologia]. E-mail: fleiuss@hucff.ufrj.br; Rosenthal, D. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Biofisica Carlos Chagas Filho. Lab. de Fisiologia Endocrina]. E-mail: doris@biof.ufrj.br

    2007-07-01

    Zinc is an essential element that can be found in bones, such as calcium and phosphorus. It seems to have effects on growth, bone turnover and mineralization making its relationship with bones still opening. The goal of this study is, by XRF analysis, characterized bone samples, with and without pathology, in the trabecular region. For that purpose, it was used an XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results show that the profile of the zinc distribution and its concentration on femoral heads are strongly related to the associated pathology. (author)

  14. Progress in neural plasticity

    Institute of Scientific and Technical Information of China (English)

    POO; Mu-Ming

    2010-01-01

    One of the properties of the nervous system is the use-dependent plasticity of neural circuits.The structure and function of neural circuits are susceptible to changes induced by prior neuronal activity,as reflected by short-and long-term modifications of synaptic efficacy and neuronal excitability.Regarded as the most attractive cellular mechanism underlying higher cognitive functions such as learning and memory,activity-dependent synaptic plasticity has been in the spotlight of modern neuroscience since 1973 when activity-induced long-term potentiation(LTP) of hippocampal synapses was first discovered.Over the last 10 years,Chinese neuroscientists have made notable contributions to the study of the cellular and molecular mechanisms of synaptic plasticity,as well as of the plasticity beyond synapses,including activity-dependent changes in intrinsic neuronal excitability,dendritic integration functions,neuron-glia signaling,and neural network activity.This work highlight some of these significant findings.

  15. Efficacy of highly bioavailable zinc from fortified water

    NARCIS (Netherlands)

    Galetti, Valeria; Kujinga, Prosper; Mitchikpè, C.E.S.; Zeder, Christophe; Tay, Fabian; Tossou, Félicien; Hounhouigan, Joseph D.; Zimmermann, Michael B.; Moretti, Diego

    2015-01-01

    Background: Zinc deficiency and contaminated water are major contributors to diarrhea in developing countries. Food fortification with zinc has not shown clear benefits, possibly because of low zinc absorption from inhibitory food matrices. We used a novel pointof-use water ultrafiltration device

  16. Height, zinc and soil-transmitted helminth infections in schoolchildren

    DEFF Research Database (Denmark)

    de Gier, Brechje; Mpabanzi, Liliane; Vereecken, Kim;

    2015-01-01

    on height, STH infection and zinc concentration in either plasma (Cambodia) or hair (Cuba). We analyzed whether STH and/or zinc were associated with height for age z-scores and whether STH and zinc were associated. In Cuba, STH prevalence was 8.4%; these were mainly Ascaris lumbricoides and Trichuris...

  17. Comparative analysis of salivary zinc level in recurrent herpes labialis

    Directory of Open Access Journals (Sweden)

    Faezeh Khozeimeh

    2012-01-01

    Conclusion: According to the results, zinc level is significantly lower in acute phase than in convalescent phase and significantly lower in both phases compared to healthy individuals,so determination of serum zinc level and prescribing zinc complement in low serum status has both treatmental and preventive effects in RHL patients.

  18. Reinvestigation of growth of 'L-valine zinc sulphate' crystal.

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R; Jyai, Rita N

    2014-01-01

    A reinvestigation of the growth of l-valine zinc sulphate crystal is reported. The slow evaporation of an aqueous solution containing l-valine and zinc sulphate heptahydrate results in the fractional crystallization of l-valine and not the organic inorganic hybrid nonlinear optical l-valine zinc sulphate crystal, as reported by Puhal Raj and Ramachandra Raja (2012).

  19. Zinc oxide's hierarchical nanostructure and its photocatalytic properties

    DEFF Research Database (Denmark)

    Kanjwal, Muzafar Ahmed; Sheikh, Faheem A.; Barakat, Nasser A. M.

    2012-01-01

    In this study, a new hierarchical nanostructure that consists of zinc oxide (ZnO) was produced by the electrospinning process followed by a hydrothermal technique. First, electrospinning of a colloidal solution that consisted of zinc nanoparticles, zinc acetate dihydrate and poly(vinyl alcohol...

  20. Crosstalk between Zinc Status and Giardia Infection: A New Approach

    Directory of Open Access Journals (Sweden)

    Humberto Astiazarán-García

    2015-06-01

    Full Text Available Zinc supplementation has been shown to reduce the incidence and prevalence of diarrhea; however, its anti-diarrheal effect remains only partially understood. There is now growing evidence that zinc can have pathogen-specific protective effects. Giardiasis is a common yet neglected cause of acute-chronic diarrheal illness worldwide which causes disturbances in zinc metabolism of infected children, representing a risk factor for zinc deficiency. How zinc metabolism is compromised by Giardia is not well understood; zinc status could be altered by intestinal malabsorption, organ redistribution or host-pathogen competition. The potential metal-binding properties of Giardia suggest unusual ways that the parasite may interact with its host. Zinc supplementation was recently found to reduce the rate of diarrhea caused by Giardia in children and to upregulate humoral immune response in Giardia-infected mice; in vitro and in vivo, zinc-salts enhanced the activity of bacitracin in a zinc-dose-dependent way, and this was not due to zinc toxicity. These findings reflect biological effect of zinc that may impact significantly public health in endemic areas of infection. In this paper, we shall explore one direction of this complex interaction, discussing recent information regarding zinc status and its possible contribution to the outcome of the encounter between the host and Giardia.

  1. Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

    Science.gov (United States)

    Chen, Ailiang; Li, Mengchun; Qian, Zhen; Ma, Yutian; Che, Jianyong; Ma, Yalin

    2016-10-01

    With the gradual depletion of zinc sulfide ores, exploration of zinc oxide ores is becoming more and more important. Hemimorphite is a major zinc oxide ore, attracting much attention in the field of zinc metallurgy although it is not the major zinc mineral. This paper presents a critical review of the treatment for extraction of zinc with emphasis on flotation, pyrometallurgical and hydrometallurgical methods based on the properties of hemimorphite. The three-dimensional framework structure of hemimorphite with complex linkage of its structural units lead to difficult desilicification before extracting zinc in the many metallurgical technologies. It is found that the flotation method is generally effective in enriching zinc minerals from hemimorphite ores into a high-grade concentrate for recovery of zinc. Pure zinc can be produced from hemimorphite or/and willemite with a reducing reagent, like methane or carbon. Leaching reagents, such as acid and alkali, can break the complex structure of hemimorphite to release zinc in the leached solution without generation of silica gel in the hydrometallurgical process. For optimal zinc extraction, combing flotation with pyrometallurgical or hydrometallurgical methods may be required.

  2. Analysis of cellular responses of macrophages to zinc ions and zinc oxide nanoparticles: a combined targeted and proteomic approach

    Science.gov (United States)

    Triboulet, Sarah; Aude-Garcia, Catherine; Armand, Lucie; Gerdil, Adèle; Diemer, Hélène; Proamer, Fabienne; Collin-Faure, Véronique; Habert, Aurélie; Strub, Jean-Marc; Hanau, Daniel; Herlin, Nathalie; Carrière, Marie; van Dorsselaer, Alain; Rabilloud, Thierry

    2014-05-01

    Two different zinc oxide nanoparticles, as well as zinc ions, are used to study the cellular responses of the RAW 264 macrophage cell line. A proteomic screen is used to provide a wide view of the molecular effects of zinc, and the most prominent results are cross-validated by targeted studies. Furthermore, the alteration of important macrophage functions (e.g. phagocytosis) by zinc is also investigated. The intracellular dissolution/uptake of zinc is also studied to further characterize zinc toxicity. Zinc oxide nanoparticles dissolve readily in the cells, leading to high intracellular zinc concentrations, mostly as protein-bound zinc. The proteomic screen reveals a rather weak response in the oxidative stress response pathway, but a strong response both in the central metabolism and in the proteasomal protein degradation pathway. Targeted experiments confirm that carbohydrate catabolism and proteasome are critical determinants of sensitivity to zinc, which also induces DNA damage. Conversely, glutathione levels and phagocytosis appear unaffected at moderately toxic zinc concentrations.Two different zinc oxide nanoparticles, as well as zinc ions, are used to study the cellular responses of the RAW 264 macrophage cell line. A proteomic screen is used to provide a wide view of the molecular effects of zinc, and the most prominent results are cross-validated by targeted studies. Furthermore, the alteration of important macrophage functions (e.g. phagocytosis) by zinc is also investigated. The intracellular dissolution/uptake of zinc is also studied to further characterize zinc toxicity. Zinc oxide nanoparticles dissolve readily in the cells, leading to high intracellular zinc concentrations, mostly as protein-bound zinc. The proteomic screen reveals a rather weak response in the oxidative stress response pathway, but a strong response both in the central metabolism and in the proteasomal protein degradation pathway. Targeted experiments confirm that carbohydrate

  3. Reduced serum zinc levels while improving growth of underweight school children in trial of zinc-fortified milk in Indonesia

    Directory of Open Access Journals (Sweden)

    Endang Dewi Lestari

    2012-03-01

    Full Text Available Background Most children in low-income countries have inadequate dietary zinc. The study was aimed to demonstrate the effect of iron-zinc fortified milk in improving zinc status among underweight school children in Indonesia. Objective To evaluate the effects of milk fortification with zinc on serum zinc levels in underweight Indonesian school children. Methods A double-blind, randomized, controlled, communitybased study was conducted on 426 underweight children aged 7 to 9 years in several low economic income level elementary schools in Jakarta and Solo . Subjects were randomly allocated to receive either zinc-fortified milk (n= 217 or standard milk (n=209 for 6 months. The fortified milk provided an 2.38 mg zinc per day and the standard milk provided 0.88 mg zinc per day. Results Among underweight children, the prevalence of stunting with a height-for-age z-score < −2.0 SD was 39.7%. Almost all subjects (98% had zinc intake of less than 60% of the Indonesian recommended daily allowance (RDA for that particular age group. After receiving the milk intervention, mean serum zinc concentration declined significantly in both groups (from 13.50 + 3.05 μmol/L at baseline to 10.59 + 1.93 μmol/L, P< 0.05, but growth parameters (weight and height improved. Conclusion Reduced mean serum zinc levels were observed in children who received standard milk, as well as those who received zinc-fortified milk. These reduction in serum zinc levels may be a part of homeostatic control mechanim for improving the negative zinc balance in zinc pools, as a negative effect on linear growth was not observed. Larger clinical trials of adequate sample size need to be conducted in order to provide better understanding on zinc regulation among underweight school children. [Paediatr Indones. 2012;52:118-24].

  4. A case of transient zinc deficiency in a breast-fed preterm infant successfully treated with oral zinc supplementation: review of zinc metabolism and related diseases.

    Science.gov (United States)

    Mandato, F; Rubegni, P; Buonocore, G; Fimiani, M

    2009-12-01

    A 15-week-old baby girl, born at the 29 week of gestation, presented with a four-week history of demarcated, erythematous, erosive and exudative patches on the perianal, perioral and acral areas. A clinical diagnosis of zinc deficiency was considered. Serum zinc level was decreased (0.5 mg/L; normal 0.70-1.50 mg/L), the mother's serum and milk had normal zinc values. The baby was started an empiric trial of oral zinc supplementation (3 mg zinc gluconate/kg body weight/ day) with complete healing of lesions after two weeks. Treatment was gradually withdrawn at six months of age with no relapse. Transient zinc deficiency due to increased zinc requirements in breast-fed mainly preterm infants is a condition similar to acrodermatitis enteropathica, an autosomal recessive disorder of enteric zinc absorption affecting almost exclusively not breast-fed infants. Early recognition of the disorder and introduction of zinc supplementation rapidly reverses transient zinc deficiency, that probably will become more and more frequent, because of the rising rate of premature infants with breast-feeding only.

  5. The Limiting Phenomena at the Anode of the Electrowinning of Zinc from Zinc Chloride in a Molten Chloride Electrolyte

    NARCIS (Netherlands)

    Lans, S.C.

    2004-01-01

    The objective of this research is to investigate the possibilities and technological viability for the electrowinning of zinc from zinc chloride. This research contributes to development of an alternative process, because it provides: ⢠A clear understanding and overview of the present zinc industr

  6. Effectiveness of zinc fortified drinking water on zinc intake, status and morbidity of rural Kenyan pre-school children

    NARCIS (Netherlands)

    Kujinga-Chopera, P.

    2016-01-01

    Background: Zinc deficiency is considered a significant public health problem in preschool children in Africa together with infections such as diarrhea, which further deplete the body of zinc. Young children are more vulnerable to zinc deficiency due to increased requirements and fr

  7. Nickel doped zinc oxide nanoparticles produced by hydrothermal decomposition of nickel-doped zinc hydroxide nitrate

    Institute of Scientific and Technical Information of China (English)

    Mohammad Yeganeh Ghotbi

    2012-01-01

    Zinc hydroxide nitrate,an anionic exchanger layered material,undoped as well as doped with 2-10% nickel,was synthesized by using a pH-controlled precipitation method.The layered materials were then used to produce the undoped and nickel-doped zinc oxides by hydrothermal-treatment.X-ray diffraction,Fourier transform infrared spectroscopy and scanning electron microscopy confirmed the formation of pure phase undoped and nickel-doped layered materials,as well as the products of the hydrothermaltreated materials,nanostructured zinc oxides.Optical studies of the nanostructured zinc oxides showed a decrease in band gap with increasing content of the doping agent,nickel.

  8. Influence of concentration of zinc ions on electrocrystallization process of zinc

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhao

    2005-01-01

    Cyclic voltammetry, chronoamperometry and scanning electron microscopy were employed to study the influence of Zn2+ ion concentration in electrolyte solutions on zinc electroplating process. The results show that, at high overpotentials, the nucleation of zinc is instantaneous, and nuclear density increases with the overpotentials increasing. While at low overpotentials, the zinc may be preferentially electrodeposited on surface inhomogeneities such as emergence points of edge, screw dislocations, atomic disorder, kink sites, or monoatomic steps, and no distinguished nucleation current can be observed. The major dissolution peak in cyclic voltammogram drifts positively due to the change of the rate-determining step of zinc electroplating processes from diffusion to the electrochemical reaction with the increase of Zn2+ ion concentration.

  9. Thermodynamics and kinetics of extracting zinc from zinc oxide ore by the ammonium sulfate roasting method

    Science.gov (United States)

    Sun, Yi; Shen, Xiao-yi; Zhai, Yu-chun

    2015-05-01

    Thermodynamic analyses and kinetic studies were performed on zinc oxide ore treatment by (NH4)2SO4 roasting technology. The results show that it is theoretically feasible to realize a roasting reaction between the zinc oxide ore and (NH4)2SO4 in a temperature range of 573-723 K. The effects of reaction temperature and particle size on the extraction rate of zinc were also examined. It is found that a surface chemical reaction is the rate-controlling step in roasting kinetics. The calculated activation energy of this process is about 45.57 kJ/mol, and the kinetic model can be expressed as follows: 1 - (1 - α)1/3 = 30.85 exp(-45.57/ RT)· t. An extraction ratio of zinc as high as 92% could be achieved under the optimum conditions.

  10. Synthetic silver oxide and mercury-free zinc electrodes for silver-zinc reserve batteries

    Science.gov (United States)

    Smith, David F.; Gucinski, James A.

    Reserve activated silver oxide-zinc cells were constructed with synthetic silver oxide (Ag 2O) electrodes with Pb-treated zinc electrodes produced by a non-electrolytic process. The cells were tested before and after thermally accelerated aging. At discharge rates up to 80 mA cm -2, the discharge was limited by the Ag 2O electrode, with a coulombic efficiency between 89-99%. At higher rates, the cells are apparently zinc-limited. Test cells were artificially aged at 90°C for 19 h and discharged at 21°C at 80 mA cm -2. No capacity loss was measured, but a delayed activation rise time was noted (192 ms fresh vs. 567 ms aged). The delay is thought to be caused by zinc passivation due to the outgassing of cell materials.

  11. Trimaran Resistance Artificial Neural Network

    Science.gov (United States)

    2011-01-01

    11th International Conference on Fast Sea Transportation FAST 2011, Honolulu, Hawaii, USA, September 2011 Trimaran Resistance Artificial Neural Network Richard...Trimaran Resistance Artificial Neural Network 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e... Artificial Neural Network and is restricted to the center and side-hull configurations tested. The value in the parametric model is that it is able to

  12. Zinc finger protein 521 overexpression increased transcript levels of Fndc5 in mouse embryonic stem cells

    Indian Academy of Sciences (India)

    Motahere-Sadat Hashemi; Abbas Kiani Esfahani; Maryam Peymani; Alireza Shoaraye Nejati; Kamran Ghaedi; Mohammad Hossein Nasr-Esfahani; Hossein Baharvand

    2016-03-01

    Zinc finger protein 521 is highly expressed in brain, neural stem cells and early progenitors of the human hematopoietic cells. Zfp521 triggers the cascade of neurogenesis inmouse embryonic stemcells through inducing expression of the early neuroectodermal genes Sox1, Sox3 and Pax6. Fndc5, a precursor of Irisin has inducing effects on the expression level of brain derived neurotrophic factor in hippocampus. Therefore, it is most likely that Fndc5 may play an important role in neural differentiation. To exhibit whether the expression of this protein is under regulation with Zfp521, we overexpressed Zfp521 in a stable transformants of mESCs expressing EGFP under control of Fndc5 promoter. Increased expression of Zfp521 enhanced transcription levels of both EGFP and endogenous Fndc5. This result was confirmed by overexpression the aforementioned vectors in HEK cells and indicated that Zfp521 functions upstream of Fndc5 expression. It is most likely that Zfp521 may act through the binding to its response element on Fndc5 core promoter. Therefore it is concluding that an enhanced expression of Fndc5 in neural progenitor cells is stimulated by Zfp521 overexpression in these cells.

  13. Zinc Transporters and Zinc Signaling: New Insights into Their Role in Type 2 Diabetes

    OpenAIRE

    Myers, Stephen A.

    2015-01-01

    Zinc is an essential trace element that plays a vital role in many biological processes including growth and development, immunity, and metabolism. Recent studies have highlighted zinc’s dynamic role as a “cellular second messenger” in the control of insulin signaling and glucose homeostasis. Accordingly, mechanisms that contribute to dysfunctional zinc signaling are suggested to be associated with metabolic disease states including cancer, cardiovascular disease, Alzheimer’s disease, and dia...

  14. [Artificial neural networks in Neurosciences].

    Science.gov (United States)

    Porras Chavarino, Carmen; Salinas Martínez de Lecea, José María

    2011-11-01

    This article shows that artificial neural networks are used for confirming the relationships between physiological and cognitive changes. Specifically, we explore the influence of a decrease of neurotransmitters on the behaviour of old people in recognition tasks. This artificial neural network recognizes learned patterns. When we change the threshold of activation in some units, the artificial neural network simulates the experimental results of old people in recognition tasks. However, the main contributions of this paper are the design of an artificial neural network and its operation inspired by the nervous system and the way the inputs are coded and the process of orthogonalization of patterns.

  15. Height, zinc and soil-transmitted helminth infections in schoolchildren

    DEFF Research Database (Denmark)

    de Gier, Brechje; Mpabanzi, Liliane; Vereecken, Kim;

    2015-01-01

    Soil-transmitted helminth (STH) infections and zinc deficiency are often found in low- and middle-income countries and are both known to affect child growth. However, studies combining data on zinc and STH are lacking. In two studies in schoolchildren in Cuba and Cambodia, we collected data...... on height, STH infection and zinc concentration in either plasma (Cambodia) or hair (Cuba). We analyzed whether STH and/or zinc were associated with height for age z-scores and whether STH and zinc were associated. In Cuba, STH prevalence was 8.4%; these were mainly Ascaris lumbricoides and Trichuris...

  16. West Mining Expanding Into Lead Zinc Smelting Industry

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>West Mining,China’s 2nd largest lead zinc miner(only next to Yunnan Jinding Zinc with an annual lead and zinc output of approx. 180,000 tons in metal content),has been put- ting efforts on the control of resources for years.Additionally,it has recently increased its investment on smelting business by holding shares of Bayanzhuoer Zijin for more zinc smelting asset.West Mining has just com- pleted the construction of its 60,000-ton zinc

  17. CHANGES OF ZINC CONTAMINATION IN HIPPOCAMPUS CELLS OF ADRENALECTOMIZED RATS

    Directory of Open Access Journals (Sweden)

    Bondaruyk О.А.

    2013-09-01

    Full Text Available Adrenalectomy causes the decline of zinc maintenance in the neurons of hippocampus and B cells of pancreas that has been observed in experiments on rats. The loss of zinc of these cells has been partly compensated by the injection of adrenalin and prednizolon to the adrenalectomized animals. The increase of zinc maintenance in these cells has been caused by the sharp-stress process due to the simultaneous physical activity and immobilization. The given data prove the participation of adrenal glands in the mechanism of zinc exchanges regulation in central (hippocampus and peripheral (cells B of pancreas zinc-containing organs of animals.

  18. Magnesium removal in the electrolytic zinc industry

    NARCIS (Netherlands)

    Booster, J.L.

    2003-01-01

    Electrolytic zinc plants need to take measures to control the magnesium content in their process liquors, because the natural magnesium bleed does not balance the input from concentrates. Presently used methods are environmentally unfriendly (due to the production of large amounts of waste gypsum) o

  19. Zinc finger structure-function in Ikaros

    Institute of Scientific and Technical Information of China (English)

    Marvin; A; Payne

    2011-01-01

    The zinc finger motif was used as a vehicle for the initial discovery of Ikaros in the context of T-cell differentiation and has been central to all subsequent analyses of Ikaros function.The Ikaros gene is alternately spliced to produce several isoforms that confer diversity of function and consequently have complicated analysis of the function of Ikaros in vivo.Key features of Ikaros in vivo function are associated with six C2H2 zinc fingers;four of which are alternately incorporated in the production of the various Ikaros isoforms.Although no complete structures are available for the Ikaros protein or any of its family members,considerable evidence has accumulated about the structure of zinc fingers and the role that this structure plays in the functions of the Ikaros family of proteins.This review summarizes the structural aspects of Ikaros zinc fingers,individually,and in tandem to provide a structural context for Ikaros function and to provide a structural basis to inform the design of future experiments with Ikaros and its family members.

  20. Fibrous zinc anodes for high power batteries

    Science.gov (United States)

    Zhang, X. Gregory

    This paper introduces newly developed solid zinc anodes using fibrous material for high power applications in alkaline and large size zinc-air battery systems. The improved performance of the anodes in these two battery systems is demonstrated. The possibilities for control of electrode porosity and for anode/battery design using fibrous materials are discussed in light of experimental data. Because of its mechanical integrity and connectivity, the fibrous solid anode has good electrical conductivity, mechanical stability, and design flexibility for controlling mass distribution, porosity and effective surface area. Experimental data indicated that alkaline cells made of such anodes can have a larger capacity at high discharging currents than commercially available cells. It showed even greater improvement over commercial cells with a non-conventional cell design. Large capacity anodes for a zinc-air battery have also been made and have shown excellent material utilization at various discharge rates. The zinc-air battery was used to power an electric bicycle and demonstrated good results.

  1. Photoemission studies of wurtzite zinc oxide.

    Science.gov (United States)

    Powell, R. A.; Spicer, W. E.; Mcmenamin, J. C.

    1972-01-01

    The electronic structure of wurtzite zinc oxide, investigated over the widest possible photon energy range by means of photoemission techniques, is described. Of particular interest among the results of the photoemission study are the location of the Zn 3rd core states, the width of the upper valence bands, and structure in the conduction-band and valence-band density of states.

  2. Zinc biofortification of cereals: problems and solutions

    DEFF Research Database (Denmark)

    Palmgren, Michael G; Clemens, Stephan; Williams, Lorraine E;

    2008-01-01

    The goal of biofortification is to develop plants that have an increased content of bioavailable nutrients in their edible parts. Cereals serve as the main staple food for a large proportion of the world population but have the shortcoming, from a nutrition perspective, of being low in zinc...

  3. Zinc fate in animal husbandry systems.

    Science.gov (United States)

    Romeo, A; Vacchina, V; Legros, S; Doelsch, E

    2014-11-01

    Zinc (Zn) is considered in animal production systems as both an essential nutrient and a possible pollutant. While it is generally supplemented at low levels in animal diets, with less than 200 mg kg(-1) in complete feeds, it is under scrutiny due to potential accumulation in the environment. This explains why international regulations limit maximum supplementation levels in animal feeds in a stricter way. This article gives an overview of the current knowledge on the fate of zinc in animal production systems, from animal diets to animal wastes. Some analytical methods can be used for the quantification and qualification of Zn chemical forms: X-ray crystallography, electrospray tandem mass spectrometry, separation techniques, hyphenated techniques… Analysis of chelated forms issued from complex matrices, like hydrolysed proteins, remains difficult, and the speciation of Zn in diluted carriers (premix and feed) is a challenge. Our understanding of Zn absorption has made progress with recent research on ZnT/Zip families and metallothioneins. However, fine-tuned approaches towards the nutritional and metabolic interactions for Zn supplementation in farm conditions still require further studies. The speciation of zinc in pig manure and poultry litter has been a priority as monogastric animals are usually raised under intensive conditions and fed with high quantities of trace minerals, leading to high animal density and elevated quantities of zinc from animal wastes.

  4. Calcium And Zinc Deficiency In Preeclamptic Women

    Directory of Open Access Journals (Sweden)

    Sultana Ferdousi

    2011-12-01

    Full Text Available Background: Pre-eclampsia is the most common medical complication of pregnancy associated withincreased maternal and infant mortality and morbidity. Reduced serum calcium and zinc levels arefound associated with elevated blood pressure in preeclampsia. Objective: To observe serum calciumand zinc levels in preeclamptic women. Methods: This cross sectional study was carried out in theDepartment of Physiology, Bangabandhu Sheikh Mujib Medical University, Shahbag, Dhaka betweenJuly 2009 to June 2010. In this study, 60 pregnant women of preeclampsia, aged 18-39 years withgestational period more than 20th weeks were included as the study (group B. For comparison ageand gestational period matched 30 normotensive pregnant women control (group A were also studied.All the subjects were selected from Obstetric and Gynae In and Out patient Department of BSMMUand Dhaka Medical College Hospital. Serum calcium was measured by Colorimetric method and serumzinc was measured by Spectrophotometric method. Data were analysed by independent sample t testand Pearson’s correlation coefficient test. Results: Mean serum calcium and zinc levels weresignificantly (p<0.001 lower in study group than those of control group. Again, serum calcium andzinc showed significant negative correlation with SBP and DBP in preeclamptic women. Conclusion:This study concludes that serum calcium and zinc deficiency may be one of the risk factor ofpreeclampsia. Therefore, early detection and supplementation to treat this deficiency may reduce theincidence of preeclampsia.

  5. Zinc finger peptide based optic sensor for detection of zinc ions.

    Science.gov (United States)

    Verma, Neelam; Kaur, Gagandeep

    2016-12-15

    In the present work, polyacrylamide gel has been used as a matrix for the immobilization of zinc finger peptide and fluorescent dye acrydine orange on the micro well plate to fabricate the fluorescence based biosensor for the detection of zinc ions in milk samples. The fluorescent dye moves in the hydrophobic groove formed after folding of the peptide in the presence of zinc ions. Under optimized conditions, linear range was observed between 0.001µg/l to 10µg/l of Zinc ions, with a lowest detection limit of 0.001µg/l and response time of 5min. Presented biosensor has shown 20% decrease in fluorescent intensity values after 5 regenerations and stable for more than one month, stored at 4°C. Interference study with other metal ions like lead, cadmium and copper showed a negligible change in fluorescence intensity in comparison to zinc ions. Developed bio sensing system was found to be novel, quick, reliable, miniaturized, stable, reproducible and repeatable and specific for zinc ion, which has been applied to various milk samples.

  6. Effects of zinc on static and dynamic mechanical properties of copper-zinc alloy

    Institute of Scientific and Technical Information of China (English)

    马志超; 赵宏伟; 鲁帅; 程虹丙

    2015-01-01

    The effects of adding alloy element zinc on the static and dynamic mechanical properties of copper-zinc alloy were investigated. Tensile and low cycle fatigue behaviors of the C11000 copper and H63 copper-zinc alloy were obtained by using a miniature tester that combined the functions of in situ tensile and fatigue testing. A piezoelectric actuator was adopted as the actuator for the fatigue testing, and the feasibility of the fatigue actuator was verified by the transient harmonic response analysis based on static tensile preload and dynamic sinusoidal load. The experimental results show that the yield strength and tensile strength of the C11000 copper are improved after adding 37% (mass fraction) zinc, and H63 copper-zinc alloy presents more obvious cyclic hardening behavior and more consumed irreversible plastic work during each stress cycle compared with C11000 copper for the same strain controlled cycling. Additionally, based on the Manson-Coffin theory, the strain-life equations of the two materials were also obtained. C11000 copper and H63 copper-zinc alloy show transition life of 16832 and 1788 cycles, respectively.

  7. Kinetics of the intestinal uptake of zinc acexamate in normal and zinc-depleted rats.

    Science.gov (United States)

    Torres-Molina, F; Martínez-Coscollá, A; Gisbert, S; Quintana, E; Sendrós, S; Peris-Ribera, J E; Plá-Delfina, J M

    1990-10-01

    The uptake of zinc as acexamic acid salt in the small intestine of the anaesthetized rat was shown to be a two-phase process in normal animals. The first phase is rapid mucosal binding which satisfies the Freundlich isotherm equation and which involves about 30 per cent of the initially perfused zinc. The second phase was characterized as an apparent absorption step which obeys Michaelis-Menten and first-order combined kinetics, with the following parameters: Vm = 6.51 mg h-1; Km = 2.96 mg; ka = 0.306 h-1. In largely non-saturated conditions, an apparent global rate constant of about 2.50 h-1 was calculated. No significant interference due to endogenous zinc excretion into the small intestine was observed during the absorption period. In zinc-deficient animals, the two phases were not so well characterized. Binding was non-linear and apparent absorption efficiency was much greater at high zinc concentrations, so no evidence of saturable kinetics was found, thus confirming the hypothesis of a homeostatic zinc regulation mechanism.

  8. Prediction of DNA-binding specificity in zinc finger proteins

    Indian Academy of Sciences (India)

    Sumedha Roy; Shayoni Dutta; Kanika Khanna; Shruti Singla; Durai Sundar

    2012-07-01

    Zinc finger proteins interact via their individual fingers to three base pair subsites on the target DNA. The four key residue positions −1, 2, 3 and 6 on the alpha-helix of the zinc fingers have hydrogen bond interactions with the DNA. Mutating these key residues enables generation of a plethora of combinatorial possibilities that can bind to any DNA stretch of interest. Exploiting the binding specificity and affinity of the interaction between the zinc fingers and the respective DNA can help to generate engineered zinc fingers for therapeutic purposes involving genome targeting. Exploring the structure–function relationships of the existing zinc finger–DNA complexes can aid in predicting the probable zinc fingers that could bind to any target DNA. Computational tools ease the prediction of such engineered zinc fingers by effectively utilizing information from the available experimental data. A study of literature reveals many approaches for predicting DNA-binding specificity in zinc finger proteins. However, an alternative approach that looks into the physico-chemical properties of these complexes would do away with the difficulties of designing unbiased zinc fingers with the desired affinity and specificity. We present a physico-chemical approach that exploits the relative strengths of hydrogen bonding between the target DNA and all combinatorially possible zinc fingers to select the most optimum zinc finger protein candidate.

  9. Zinc in thalassemic patients and its relation with depression.

    Science.gov (United States)

    Moafi, Alireza; Mobaraki, Gholamhossein; Taheri, Seyed Sadr; Heidarzadeh, Abtin; Shahabi, Iraj; Majidi, Farshad

    2008-01-01

    Studies have shown that there is a relationship between zinc levels and depression. Thalassemic patients are at risk of zinc deficiency due to various causes including Desferal injection. The aim of this study, therefore, is to investigate hair zinc levels in thalassemic patients and their association with depression. For the purposes of this survey, 50 patients with major thalassemia between 10-20 years old were selected randomly. The patients' hair zinc concentration was compared with a control group of similarly aged healthy individuals. Simultaneously, their psychological status was evaluated with either the "Beck" or "Marya Kovacs" test (according to age) so that the relation between depression and zinc concentration could be assessed. The mean hair zinc concentration in patients was more than the controls (193.96 +/- 92.4 ppm vs 149.6 +/- 72.21 ppm). Zinc deficiency was present in 10% of the patients, and 52% had some degree of depression. There was a reverse correlation between zinc deficiency and blood transfusion rate (p < 0.05). Also, while there were more incidences of depression among the zinc deficient patients, the difference was not significant. Regarding the high prevalence of depression and insignificant relation to the zinc deficiency in these thalassemic patients, this research suggests the need for further consideration concerning patients' psychological status, the risk factors of zinc deficiency, as well as extended assessment into other causes of depression.

  10. Accelerating degradation rate of pure iron by zinc ion implantation

    Science.gov (United States)

    Huang, Tao; Zheng, Yufeng; Han, Yong

    2016-01-01

    Pure iron has been considered as a promising candidate for biodegradable implant applications. However, a faster degradation rate of pure iron is needed to meet the clinical requirement. In this work, metal vapor vacuum arc technology was adopted to implant zinc ions into the surface of pure iron. Results showed that the implantation depth of zinc ions was about 60 nm. The degradation rate of pure iron was found to be accelerated after zinc ion implantation. The cytotoxicity tests revealed that the implanted zinc ions brought a slight increase on cytotoxicity of the tested cells. In terms of hemocompatibility, the hemolysis of zinc ion implanted pure iron was lower than 2%. However, zinc ions might induce more adhered and activated platelets on the surface of pure iron. Overall, zinc ion implantation can be a feasible way to accelerate the degradation rate of pure iron for biodegradable applications. PMID:27482462

  11. Preparation and Purification of Zinc Sulphinate Reagents for Organic Synthesis

    Science.gov (United States)

    O’Hara, Fionn; Baxter, Ryan D.; O’Brien, Alexander G.; Collins, Michael R.; Dixon, Janice A.; Fujiwara, Yuta; Ishihara, Yoshihiro; Baran, Phil S.

    2014-01-01

    SUMMARY The present protocol details the synthesis of zinc bis(alkanesulphinate)s that can be used as general reagents for the formation of radical species. The zinc sulphinates described herein have been generated from the corresponding sulphonyl chlorides by treatment with zinc dust. The products may be used crude, or a simple purification procedure may be performed to minimize incorporation of water and zinc chloride. Elemental analysis has been conducted in order to confirm the purity of the zinc sulphinate reagents; reactions with caffeine have also been carried out to verify the reactivity of each batch that has been synthesized. Although the synthesis of the zinc sulphinate salts generally proceeds within 3 h, workup can take up to 24 h and purification can take up to 3 h. Following the steps in this protocol would enable the user to generate a small toolkit of zinc sulphinate reagents over the course of one week. PMID:23640168

  12. Effect of Phosphate on Zinc Transport in Lou Soil

    Institute of Scientific and Technical Information of China (English)

    LUJIALONG; DONGLINGIAO; 等

    1998-01-01

    A study on the transport characteristics of zinc in lou soil with phosphate at different concentrations was carried out by the method of step input.The effects of phosphate and temperature on zinc transport were studied through analysing the diffusion-dipsersion coefficients(D) and the retardation factor(R) obtained by the program CXTFIT.The results showed that D decreased and R increased with increasig concentration of phosphate so that iv was difficult for zinc to break through the soil column,and zinc stopped to break through the column at high temperature.One order equation,double constant equation and the Elovich equation were all suitable for the escription of zinc dynamics.Effects of phosphate and temperature on zinc transport were further confirmed by the analysis on pseudo-thermodynamic parameters of zinc transport.

  13. Predicting zinc binding at the proteome level

    Directory of Open Access Journals (Sweden)

    Rosato Antonio

    2007-02-01

    Full Text Available Abstract Background Metalloproteins are proteins capable of binding one or more metal ions, which may be required for their biological function, for regulation of their activities or for structural purposes. Metal-binding properties remain difficult to predict as well as to investigate experimentally at the whole-proteome level. Consequently, the current knowledge about metalloproteins is only partial. Results The present work reports on the development of a machine learning method for the prediction of the zinc-binding state of pairs of nearby amino-acids, using predictors based on support vector machines. The predictor was trained using chains containing zinc-binding sites and non-metalloproteins in order to provide positive and negative examples. Results based on strong non-redundancy tests prove that (1 zinc-binding residues can be predicted and (2 modelling the correlation between the binding state of nearby residues significantly improves performance. The trained predictor was then applied to the human proteome. The present results were in good agreement with the outcomes of previous, highly manually curated, efforts for the identification of human zinc-binding proteins. Some unprecedented zinc-binding sites could be identified, and were further validated through structural modelling. The software implementing the predictor is freely available at: http://zincfinder.dsi.unifi.it Conclusion The proposed approach constitutes a highly automated tool for the identification of metalloproteins, which provides results of comparable quality with respect to highly manually refined predictions. The ability to model correlations between pairwise residues allows it to obtain a significant improvement over standard 1D based approaches. In addition, the method permits the identification of unprecedented metal sites, providing important hints for the work of experimentalists.

  14. Zinc therapy for different causes of diarrhea

    Directory of Open Access Journals (Sweden)

    Hafaz Zakky Abdillah

    2013-11-01

    Full Text Available Background The incidence of diarrhea in Indonesia has declined in the past five years. In spite of the increasing number of studies on the treatment for acute diarrhea, especially the use of zinc, it is not known if bacterial vs. non-bacterial etiology makes a difference in the reduction of severity of acute diarrhea in children on zinc therapy. Objective To assess the effect of zinc therapy in reducing the severity of acute bacterial and non-bacterial diarrhea. Methods We performed a cross-sectional study in the Secanggang District, Langkat Regency of North Sumatera, from August to November 2009 in children aged 2 months to 14 years. Microscopic stool examinations were undertaken to separate subjects into the acute bacterial or non-bacterial diarrhea groups. Both groups received 10 mg/day of zinc sulphate for subjects aged <6 months or 20 mg/day for those aged ≥6 months for 10 days. Measurement of disease severity was based on the frequency of diarrhea (times/day and the duration of diarrhea (hours after initial drug consumption. We performed independent T-test for statistical analysis. Results Sixty-two children participated in this study, with 31 children in the acute bacterial group, and the remainder in the non-bacterial group. There were no significant differences between the two groups in frequency of diarrhea (2.61 vs 2.70 times/day, respectively, P=0.27 or in duration of diarrhea (63.39 vs 66.68 hours, respectively, P=0.06. Conclusion Zinc is not more effective in reducing the severity of acute bacterial diarrhea compared to non-bacterial diarrhea in children. [Paediatr Indones. 2013;53:334-8.].

  15. via dynamic neural networks

    Directory of Open Access Journals (Sweden)

    J. Reyes-Reyes

    2000-01-01

    Full Text Available In this paper, an adaptive technique is suggested to provide the passivity property for a class of partially known SISO nonlinear systems. A simple Dynamic Neural Network (DNN, containing only two neurons and without any hidden-layers, is used to identify the unknown nonlinear system. By means of a Lyapunov-like analysis the new learning law for this DNN, guarantying both successful identification and passivation effects, is derived. Based on this adaptive DNN model, an adaptive feedback controller, serving for wide class of nonlinear systems with an a priori incomplete model description, is designed. Two typical examples illustrate the effectiveness of the suggested approach.

  16. Zinc transporters and their role in the pancreatic β‐cell

    OpenAIRE

    Lemaire, Katleen; Chimienti, Fabrice; Schuit, Frans

    2012-01-01

    Abstract Zinc is an essential nutrient with tremendous importance for human health, and zinc deficiency is a severe risk factor for increased mortality and morbidity. As abnormal zinc homeostasis causes diabetes, and because the pancreatic β‐cell contains the highest zinc content of any known cell type, it is of interest to know how zinc fluxes are controlled in β‐cells. The understanding of zinc homeostasis has been boosted by the discovery of multiprotein families of zinc transporters, and ...

  17. Effect of zinc fortification on Cheddar cheese quality.

    Science.gov (United States)

    Kahraman, O; Ustunol, Z

    2012-06-01

    Zinc-fortified Cheddar cheese containing 228 mg of zinc/kg of cheese was manufactured from milk that had 16 mg/kg food-grade zinc sulfate added. Cheeses were aged for 2 mo. Culture activity during cheese making and ripening, and compositional, chemical, texture, and sensory characteristics were compared with control cheese with no zinc sulfate added to the cheese milk. Compositional analysis included fat, protein, ash, moisture, zinc, and calcium determinations. The thiobarbituric acid (TBA) assay was conducted to determine lipid oxidation during aging. Texture was analyzed by a texture analyzer. An untrained consumer panel of 60 subjects evaluated the cheeses for hardness, off-flavors, appearance, and overall preference using a 9-point hedonic scale. Almost 100% of the zinc added to cheese milk was recovered in the zinc-fortified cheese. Zinc-fortified Cheddar cheese had 5 times more zinc compared with control cheese. Zinc-fortified cheese had higher protein and slightly higher fat and ash contents, whereas moisture was similar for both cheeses. Zinc fortification did not affect culture activity during cheese making or during the 2-mo aging period. The TBA value of control cheese was higher than that of zinc-fortified cheese at the end of ripening. Although zinc-fortified cheese was harder as determined by the texture analyzer, the untrained consumer panel did not detect differences in the sensory attributes and overall quality of the cheeses. Fortification of 16 mg/kg zinc sulfate in cheese milk is a suitable approach to fortifying Cheddar cheese without changing the quality of Cheddar cheese.

  18. Dietary intervention causes redistribution of zinc in obese adolescents.

    Science.gov (United States)

    Freire, Simone Cardoso; Fisberg, Mauro; Cozzolino, Silvia Maria Franciscato

    2013-08-01

    Obese people tend to have low zinc circulation levels; this is not always related to zinc intake but can reflect the distribution of zinc in relation to the proportion of body fat and factors related to the inflammatory processes that cause obesity. The purpose of this study was to assess zinc distribution in 15 obese adolescent girls before and after a nutritional orientation program. Participants ranged from 14 to 18 years old (postpubescent) and had a body fat percent (BF%) of >35 %. Zinc nutritional status and other zinc-dependent parameters, such as superoxide dismutase (SOD) and insulin levels, were assessed by biochemical analysis of plasma and erythrocytes, salivary sediment, and urine. Samples were collected before and after 4 months of dietary intervention. Dual energy X-ray absorptiometry (DXA) was used to verify BF% both at the beginning and at the end of the study. Food consumption was assessed in ten individual food questionnaires throughout the study; food groups were separated on the questionnaires in the same way as suggested by some authors to develop the Healthy Eating Index (HEI) but with the addition of zinc. After 4 months of nutritional orientation, 78 % of the participants showed a decrease in BF%. Intraerythrocytic zinc increased over the study period, while salivary sediment zinc, SOD, insulin, and Zn urinary24 h/creatinine all decreased (p zinc intake throughout the study but participants did increase their consumption of fruits, dairy, and meats during the study (p zinc and decreased levels of SOD. There was also a statistically significant correlation between BF% and Zn urinary 24h/creatinine, and SOD. All these parameters were diminished at the end of the study. The dietary intervention for obese adolescent girls is effective with decrease of BF that led to the redistribution of zinc in the body as shown by the changes in erythrocytes, plasma, salivary, urine zinc, as well as the complementary parameters of insulin and SOD. These

  19. Effects of maternal mild zinc deficiency and different ways of zinc supplementation for offspring on learning and memory

    Directory of Open Access Journals (Sweden)

    Xiaogang Yu

    2016-01-01

    Full Text Available Background: The effect of different ways of zinc supplementation on spatial learning and memory remains unclear. Objectives: This study aims to assess the effectiveness of two ways of zinc supplementation – oral use and intravenous transfusion – in zinc-deficient offspring rats on learning and memory. Design: Rats were randomly divided into six groups on the first day of pregnancy (n=12: control (CO, pair fed (PF, zinc deprived (ZD, oral zinc supplementation (OZS, injection zinc supplementation (IZS, and injection control. The offspring's spatial learning and memory were tested at postnatal day 35 using Morris water maze (MWM. Maternal rats’ serum zinc was measured at postnatal day 21, while pups’ serum zinc was measured at postnatal day 35. Results: Compared with the CO and PF groups, pups in ZD group spent more time finding the latent platform and swam longer distances (p0.05. However, compared with ZD groups, pups in IZS did not show any improvement in the indexes of MWM (p>0.05 although their zinc serum concentration increased significantly (p<0.05. Conclusions: These results indicate that mild zinc deficiency during pregnancy and lactation leads to the impairment of learning and memory function in offspring, and that OZS, instead of intravenous transfusion zinc supplementation, can recover the impairment of spatial learning and memory function.

  20. Analysis of cellular responses of macrophages to zinc ions and zinc oxide nanoparticles: a combined targeted and proteomic approach.

    Science.gov (United States)

    Triboulet, Sarah; Aude-Garcia, Catherine; Armand, Lucie; Gerdil, Adèle; Diemer, Hélène; Proamer, Fabienne; Collin-Faure, Véronique; Habert, Aurélie; Strub, Jean-Marc; Hanau, Daniel; Herlin, Nathalie; Carrière, Marie; Van Dorsselaer, Alain; Rabilloud, Thierry

    2014-06-07

    Two different zinc oxide nanoparticles, as well as zinc ions, are used to study the cellular responses of the RAW 264 macrophage cell line. A proteomic screen is used to provide a wide view of the molecular effects of zinc, and the most prominent results are cross-validated by targeted studies. Furthermore, the alteration of important macrophage functions (e.g. phagocytosis) by zinc is also investigated. The intracellular dissolution/uptake of zinc is also studied to further characterize zinc toxicity. Zinc oxide nanoparticles dissolve readily in the cells, leading to high intracellular zinc concentrations, mostly as protein-bound zinc. The proteomic screen reveals a rather weak response in the oxidative stress response pathway, but a strong response both in the central metabolism and in the proteasomal protein degradation pathway. Targeted experiments confirm that carbohydrate catabolism and proteasome are critical determinants of sensitivity to zinc, which also induces DNA damage. Conversely, glutathione levels and phagocytosis appear unaffected at moderately toxic zinc concentrations.

  1. Dietary intake of Zinc, serum levels of Zinc and risk of gastric cancer: A review of studies

    Directory of Open Access Journals (Sweden)

    Sayyed Saeid Khayyatzadeh

    2015-01-01

    Full Text Available Gastric cancer (GC is considered as most fourth common cancer in the world. Findings from animal, experimental and epidemiologic studies indicate that diet plays an important role in the etiology of stomach cancer. Among dietary factors, Zinc status has received great attention in recent years. The purpose of the present study was to review the association of serum levels of Zinc, dietary intake of Zinc and GC risk. A complete search was performed about the association of Zinc status and risk of GC was in databases electronic through such as ISI web of science, PubMed, Scopus, IrMedx and SID. Our results of current review suggest that dietary intake of Zinc and serum levels of Zinc are lower in GC patient. In other word, high serum levels of Zinc may be protective in GC risk. However, it seems further studies in particular epidemiological studies with large scale setting are required to reach a definite conclusion.

  2. The Neural Support Vector Machine

    NARCIS (Netherlands)

    Wiering, Marco; van der Ree, Michiel; Embrechts, Mark; Stollenga, Marijn; Meijster, Arnold; Nolte, A; Schomaker, Lambertus

    2013-01-01

    This paper describes a new machine learning algorithm for regression and dimensionality reduction tasks. The Neural Support Vector Machine (NSVM) is a hybrid learning algorithm consisting of neural networks and support vector machines (SVMs). The output of the NSVM is given by SVMs that take a centr

  3. Neural Networks for Optimal Control

    DEFF Research Database (Denmark)

    Sørensen, O.

    1995-01-01

    Two neural networks are trained to act as an observer and a controller, respectively, to control a non-linear, multi-variable process.......Two neural networks are trained to act as an observer and a controller, respectively, to control a non-linear, multi-variable process....

  4. The Neural Web of War

    NARCIS (Netherlands)

    Kennis, M.

    2016-01-01

    The aim of this thesis was to gain more insight in the neural network alterations that may underlie PTSD and trauma-focused therapy outcome. To investigate TheNeural Web of War brain scans of healthy civilians (n=26), and veterans with (n=58) and without (n=29) PTSD were assessed. Structural and fun

  5. Analysis of neural networks

    CERN Document Server

    Heiden, Uwe

    1980-01-01

    The purpose of this work is a unified and general treatment of activity in neural networks from a mathematical pOint of view. Possible applications of the theory presented are indica­ ted throughout the text. However, they are not explored in de­ tail for two reasons : first, the universal character of n- ral activity in nearly all animals requires some type of a general approach~ secondly, the mathematical perspicuity would suffer if too many experimental details and empirical peculiarities were interspersed among the mathematical investigation. A guide to many applications is supplied by the references concerning a variety of specific issues. Of course the theory does not aim at covering all individual problems. Moreover there are other approaches to neural network theory (see e.g. Poggio-Torre, 1978) based on the different lev­ els at which the nervous system may be viewed. The theory is a deterministic one reflecting the average be­ havior of neurons or neuron pools. In this respect the essay is writt...

  6. Neural networks in astronomy.

    Science.gov (United States)

    Tagliaferri, Roberto; Longo, Giuseppe; Milano, Leopoldo; Acernese, Fausto; Barone, Fabrizio; Ciaramella, Angelo; De Rosa, Rosario; Donalek, Ciro; Eleuteri, Antonio; Raiconi, Giancarlo; Sessa, Salvatore; Staiano, Antonino; Volpicelli, Alfredo

    2003-01-01

    In the last decade, the use of neural networks (NN) and of other soft computing methods has begun to spread also in the astronomical community which, due to the required accuracy of the measurements, is usually reluctant to use automatic tools to perform even the most common tasks of data reduction and data mining. The federation of heterogeneous large astronomical databases which is foreseen in the framework of the astrophysical virtual observatory and national virtual observatory projects, is, however, posing unprecedented data mining and visualization problems which will find a rather natural and user friendly answer in artificial intelligence tools based on NNs, fuzzy sets or genetic algorithms. This review is aimed to both astronomers (who often have little knowledge of the methodological background) and computer scientists (who often know little about potentially interesting applications), and therefore will be structured as follows: after giving a short introduction to the subject, we shall summarize the methodological background and focus our attention on some of the most interesting fields of application, namely: object extraction and classification, time series analysis, noise identification, and data mining. Most of the original work described in the paper has been performed in the framework of the AstroNeural collaboration (Napoli-Salerno).

  7. Neural relativity principle

    Science.gov (United States)

    Koulakov, Alexei

    Olfaction is the final frontier of our senses - the one that is still almost completely mysterious to us. Despite extensive genetic and perceptual data, and a strong push to solve the neural coding problem, fundamental questions about the sense of smell remain unresolved. Unlike vision and hearing, where relatively straightforward relationships between stimulus features and neural responses have been foundational to our understanding sensory processing, it has been difficult to quantify the properties of odorant molecules that lead to olfactory percepts. In a sense, we do not have olfactory analogs of ``red'', ``green'' and ``blue''. The seminal work of Linda Buck and Richard Axel identified a diverse family of about 1000 receptor molecules that serve as odorant sensors in the nose. However, the properties of smells that these receptors detect remain a mystery. I will review our current understanding of the molecular properties important to the olfactory system. I will also describe a theory that explains how odorant identity can be preserved despite substantial changes in the odorant concentration.

  8. Iron and zinc concentrations and /sup 59/Fe retention in developing fetuses of zinc-deficient rats

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.M.; Loennerdal, B.H.; Hurley, L.S.; Keen, C.L.

    1987-11-01

    Because disturbances in iron metabolism might contribute to the teratogenicity of zinc deficiency, we examined the effect of zinc deficiency on fetal iron accumulation and maternal and fetal retention of /sup 59/Fe. Pregnant rats were fed from mating a purified diet containing 0.5, 4.5 or 100 micrograms Zn/g. Laparotomies were performed on d 12, 16, 19 and 21 of gestation. Maternal blood and concepti were analyzed for zinc and iron. Additional groups of dams fed 0.5 or 100 micrograms Zn/g diet were gavaged on d 19 with a diet containing /sup 59/Fe. Six hours later maternal blood and tissues, fetuses and placentas were counted for /sup 59/Fe. Maternal plasma zinc, but not iron, concentration was affected by zinc deficiency on d 12. Embryo zinc concentration on d 12 increased with increasing maternal dietary zinc, whereas iron concentration was not different among groups. On d 16-21 plasma iron was higher in dams fed 0.5 micrograms Zn/g diet than in those fed 4.5 or 100 micrograms/g, whereas plasma zinc was lower in dams fed 0.5 or 4.5 micrograms Zn/g than in those fed 100 micrograms Zn/g diet. On d 19 zinc concentration in fetuses from dams fed 0.5 micrograms/g zinc was not different from that of those fed 4.5 micrograms/g zinc, and iron concentration was higher in the 0.5 microgram Zn/g diet group. The increase in iron concentration in zinc-deficient fetuses thus occurs too late to be involved in major structural teratogenesis. Although whole blood concentration of /sup 59/Fe was not different in zinc-deficient and control dams, zinc-deficient dams had more /sup 59/Fe in the plasma fraction.

  9. Thermal treatment for recovery of manganese and zinc from zinc-carbon and alkaline spent batteries.

    Science.gov (United States)

    Belardi, G; Lavecchia, R; Medici, F; Piga, L

    2012-10-01

    The aim of this paper is the recovery of manganese and zinc from a mixture of zinc-carbon and alkaline spent batteries, containing 40.9% of Mn and 30.1% of Zn, after preliminary physical treatment followed by removal of mercury. Separation of the metals has been carried out on the basis of their different boiling points, being 357°C and 906°C the boiling point of mercury and zinc and 1564°C the melting point of Mn(2)O(3). Characterization by chemical analysis, TGA/DTA and X-ray powder diffraction of the mixture has been carried out after comminution sieving and shaking table treatment to remove the anodic collectors and most of chlorides contained in the mixture. The mixture has been roasted at various temperatures and resident times in a flow of air to set the best conditions to remove mercury that were 400°C and 10 min. After that, the flow of air has been turned into a nitrogen one (inert atmosphere) and the temperatures raised, thus permitting the zinc oxide to be reduced to metallic zinc by the carbon present in the original mixture and recovered after volatilization as a high grade concentrate, while manganese was left in the residue. The recovery and the grade of the two metals, at 1000°C and 30 min residence time, were 84% and 100% for zinc and 85% and 63% for manganese, respectively. The recovery of zinc increased to 99% with a grade of 97% at 1200°C and 30 min residence time, while the recovery and grade of manganese were 86% and 87%, respectively, at that temperature. Moreover, the chlorinated compounds that could form by the combustion of the plastics contained in the spent batteries, are destroyed at the temperature required by the process.

  10. Medical diagnosis using neural network

    CERN Document Server

    Kamruzzaman, S M; Siddiquee, Abu Bakar; Mazumder, Md Ehsanul Hoque

    2010-01-01

    This research is to search for alternatives to the resolution of complex medical diagnosis where human knowledge should be apprehended in a general fashion. Successful application examples show that human diagnostic capabilities are significantly worse than the neural diagnostic system. This paper describes a modified feedforward neural network constructive algorithm (MFNNCA), a new algorithm for medical diagnosis. The new constructive algorithm with backpropagation; offer an approach for the incremental construction of near-minimal neural network architectures for pattern classification. The algorithm starts with minimal number of hidden units in the single hidden layer; additional units are added to the hidden layer one at a time to improve the accuracy of the network and to get an optimal size of a neural network. The MFNNCA was tested on several benchmarking classification problems including the cancer, heart disease and diabetes. Experimental results show that the MFNNCA can produce optimal neural networ...

  11. Neural fields theory and applications

    CERN Document Server

    Graben, Peter; Potthast, Roland; Wright, James

    2014-01-01

    With this book, the editors present the first comprehensive collection in neural field studies, authored by leading scientists in the field - among them are two of the founding-fathers of neural field theory. Up to now, research results in the field have been disseminated across a number of distinct journals from mathematics, computational neuroscience, biophysics, cognitive science and others. Starting with a tutorial for novices in neural field studies, the book comprises chapters on emergent patterns, their phase transitions and evolution, on stochastic approaches, cortical development, cognition, robotics and computation, large-scale numerical simulations, the coupling of neural fields to the electroencephalogram and phase transitions in anesthesia. The intended readership are students and scientists in applied mathematics, theoretical physics, theoretical biology, and computational neuroscience. Neural field theory and its applications have a long-standing tradition in the mathematical and computational ...

  12. Nosotros y el cinc We and zinc

    Directory of Open Access Journals (Sweden)

    D. I. Florea

    2012-06-01

    Full Text Available La Nutrición es la base de los procesos fisiológicos humanos. Una nutrición inadecuada puede inducir a la disfunción en eslabones de la cadena metabólica. Todos los nutrientes esenciales son imprescindibles y el déficit o exceso de cualquiera de ellos conlleva a efectos adversos en la salud. El cinc es un micronutriente extensamente demandado en el organismo, como lo demuestra la amplia diversidad de funciones biológicas que presenta. La ingesta de cinc presenta un gran margen en la población mundial actual, pudiendo ser de 7 mg/d en Reino Unido y llegando a 15 mg/d en EEUU, aunque por supuesto, las RDAs se fijan en función de la edad, sexo, situación fisiológica (embarazo, lactancia, etc., o enfermedad. Se conoce que el cinc es fundamental para la estructura y funcionamiento del DNA y así como de enzimas, coenzimas, hormonas, etc. La vida del cinc es corta, dado que la mayor cantidad se absorbe y rápidamente es transferida a depósitos, donde se almacena, por lo tanto la cantidad se cinc disponible en sangre puede no ser la cantidad "real". En el presente trabajo hemos realizado una breve revisión del paso del cinc por nuestro organismo, tratando desde su ingesta hasta su recorrido por la sangre tanto en personas sanas como enfermas.Nutrition is the basis of human physiological processes. Inadequate nutrition can lead to dysfunction in the metabolic chain links. One of the most important micronutrients is zinc, as evidenced by its wide range of carriers in the body. Zinc intake has a large margin in the current world population, may be 7 mg/d in the UK, reaching 15 mg/d in the U.S., although of course, the RDA's are set according to age, sex , physiological status (pregnancy, lactation, etc.., or disease. It is known that zinc is essential for the structure and function as well as DNA and enzymes, coenzymes, hormones and so on. Life is short, zinc, since the most rapidly absorbed and is transferred to tanks where it is stored, so

  13. Investigation of zinc biosorption by brewer's yeast cells

    Directory of Open Access Journals (Sweden)

    Dodić Siniša N.

    2005-01-01

    Full Text Available The highest amount of zinc (= 90% is bound after 3 hrs of contact at low initial (total concentrations of zinc in suspension of yeast, 10-100 mg/l at 10-30°C. The equilibrium between bound and free zinc ions is established after 6 hrs of contact time, independently on the total zinc concentration in yeast milk. No bigger changes of content of zinc bound to brewer's yeast cells was determined at temperatures 10°C and 30°C. 40% of bound zinc in the equilibrium state is bound during the first 15 min of contact of zinc ions and brewer's yeast cells at all initial (total zinc concentrations in suspension of yeast both at 10°C and 30°C. The "KEKAM" equation can be used for the description of kinetics of zinc biosorption by waste brewer's yeast cells, for the ranges of zinc concentration 10-100 mg/l at 30°C (mean correlation coefficient 0,96 and 60,0-100 mg/l at 10°C (mean correlation coefficient 0,95.

  14. Zinc and diabetes--clinical links and molecular mechanisms.

    Science.gov (United States)

    Jansen, Judith; Karges, Wolfram; Rink, Lothar

    2009-06-01

    Zinc is an essential trace element crucial for the function of more than 300 enzymes and it is important for cellular processes like cell division and apoptosis. Hence, the concentration of zinc in the human body is tightly regulated and disturbances of zinc homeostasis have been associated with several diseases including diabetes mellitus, a disease characterized by high blood glucose concentrations as a consequence of decreased secretion or action of insulin. Zinc supplementation of animals and humans has been shown to ameliorate glycemic control in type 1 and 2 diabetes, the two major forms of diabetes mellitus, but the underlying molecular mechanisms have only slowly been elucidated. Zinc seems to exert insulin-like effects by supporting the signal transduction of insulin and by reducing the production of cytokines, which lead to beta-cell death during the inflammatory process in the pancreas in the course of the disease. Furthermore, zinc might play a role in the development of diabetes, since genetic polymorphisms in the gene of zinc transporter 8 and in metallothionein (MT)-encoding genes could be demonstrated to be associated with type 2 diabetes mellitus. The fact that antibodies against this zinc transporter have been detected in type 1 diabetic patients offers new diagnostic possibilities. This article reviews the influence of zinc on the diabetic state including the molecular mechanisms, the role of the zinc transporter 8 and MT for diabetes development and the resulting diagnostic and therapeutic options.

  15. Silicon and zinc biogeochemical cycles coupled through the Southern Ocean

    Science.gov (United States)

    Vance, Derek; Little, Susan H.; de Souza, Gregory F.; Khatiwala, Samar; Lohan, Maeve C.; Middag, Rob

    2017-02-01

    Zinc is vital for the physiology of oceanic phytoplankton. The striking similarity of the depth profiles of zinc to those of silicate suggests that the uptake of both elements into the opaline frustules of diatoms, and their regeneration from these frustules, should be coupled. However, the zinc content of diatom opal is negligible, and zinc is taken up into and regenerated from the organic parts of diatom cells. Thus, since opaline frustules dissolve deep in the water column while organic material is regenerated in the shallow subsurface ocean, there is little reason to expect the observed close similarity between zinc and silicate, and the dissimilarity between zinc and phosphate. Here we combine observations with simulations using a three-dimensional model of ocean circulation and biogeochemistry to show that the coupled distribution of zinc and silicate, as well as the decoupling of zinc and phosphate, can arise in the absence of mechanistic links between the uptake of zinc and silicate, and despite contrasting regeneration length scales. Our simulations indicate that the oceanic zinc distribution is, in fact, a natural result of the interaction between ocean biogeochemistry and the physical circulation through the Southern Ocean hub. Our analysis demonstrates the importance of uptake stoichiometry in controlling ocean biogeochemistry, and the utility of global-scale elemental covariation in the ocean in understanding these controls.

  16. Identification of the Human Zinc Transcriptional Regulatory Element (ZTRE)

    Science.gov (United States)

    Coneyworth, Lisa J.; Jackson, Kelly A.; Tyson, John; Bosomworth, Helen J.; van der Hagen, Eline; Hann, Georgia M.; Ogo, Ogo A.; Swann, Daniel C.; Mathers, John C.; Valentine, Ruth A.; Ford, Dianne

    2012-01-01

    Many genes with crucial roles in zinc homeostasis in mammals respond to fluctuating zinc supply through unknown mechanisms, and uncovering these mechanisms is essential to understanding the process at cellular and systemic levels. We detected zinc-dependent binding of a zinc-induced protein to a specific sequence, the zinc transcriptional regulatory element (ZTRE), in the SLC30A5 (zinc transporter ZnT5) promoter and showed that substitution of the ZTRE abrogated the repression of a reporter gene in response to zinc. We identified the ZTRE in other genes, including (through an unbiased search) the CBWD genes and (through targeted analysis) in multiple members of the SLC30 family, including SLC30A10, which is repressed by zinc. The function of the CBWD genes is currently unknown, but roles for homologs in metal homeostasis are being uncovered in bacteria. We demonstrated that CBWD genes are repressed by zinc and that substitution of the ZTRE in SLC30A10 and CBWD promoter-reporter constructs abrogates this response. Other metals did not affect expression of the transcriptional regulator, binding to the ZTRE or promoter-driven reporter gene expression. These findings provide the basis for elucidating how regulation of a network of genes through this novel mechanism contributes to zinc homeostasis and how the cell orchestrates this response. PMID:22902622

  17. Assimilation of zinc by Porcellio scaber (Isopoda, Crustacea) exposed to zinc

    Energy Technology Data Exchange (ETDEWEB)

    Bibic, A.; Drobne, D.; Strus, J. [Univ. of Ljubijana (Slovenia)

    1997-05-01

    The ability of terrestrial isopods to accumulate high amounts of metals, to survive in industrially polluted areas and respond to environmental contaminants in a dose-dependent manner makes them one of the most favorite experimental organisms for terrestrial ecotoxicology. Understanding metal uptake, assimilation and loss by these animals is important to explain how they cope with polluted environments. Metal uptake depends on the rate of food consumption, on metal availability in the food, on the pH inside the gut and some other factors. Isopods respond to high metal concentrations in the food in different ways and try to avoid the negative effects of metal poisoning. Zinc is one of the metals present in high concentrations in industrially polluted areas. Zinc poisoning may be avoided by the regulation of the consumption rate, by behavioral response, by storing metals in the hepatopancreas as insoluble granules, and by fecal, and possibly urinary, excretion. Zinc in organisms is a constituent of more than 200 metalloenzymes and other metabolic compounds and assures stability of biological molecules and structures. High Zn levels in food cause a reduction of feeding rate, affect growth and reproduction, cause changes in the structure of the digestive glands and influence the duration of the molting cycle. The present study investigated zinc assimilation by Porcellio scaber exposed to leaves contaminated with radioactively labeled zinc at five different concentrations. 17 refs., 2 figs., 2 tabs.

  18. Zinc injection in German PWR plants

    Energy Technology Data Exchange (ETDEWEB)

    Stellwag, B. [Framatome ANP GmbH, Erlangen (Germany); Juergensen, M. [Kernkraftwerk Obrigheim GmbH (Germany); Wolter, D. [RWE Power AG, Kraftwerk Biblis (Germany)

    2002-07-01

    Zinc injection for further reduction of radiation fields was introduced at Unit B of Biblis Nuclear Power Station in September 1996 and at Obrigheim Nuclear Power Station in February 1998. Zinc injection is still being implemented today at these plants. This paper gives an overview of the experience acquired with the method, including the annual refueling outages in the year 2001. The main topic addressed by the paper is the evolution of dose rates at the primary system and work-related doses since introduction of the method. Reductions in high dose rate areas have meanwhile achieved values of 40 to 50%. Annual collective doses per man-hour spent in the controlled access area of the plant as well as personal doses for specific activities are also decreasing. (authors)

  19. Zinc-redox battery: A technology update

    Science.gov (United States)

    Hollandsworth, R. P.

    Since 1977, scientists at Lockheed Missiles and Space Company, Inc., have been developing the Zinc-Redox Battery for large-scale electrical energy storage. The current state of technology for this battery has demonstrated a number of positive features: (1) high energy efficiency (82.6 +/- 4.4%) demonstrated for more than 754 cycles with a low-cost alpha-methyl styrene membrane; (2) minimal environmental concerns because the only toxic reactant is 2N sodium hydroxide, and thus low projected balance-of-plant costs; and (3) good cell performance over a wide range of discharge rates with cell IR being the main determinant of energy efficiency. Current studies have focused on zinc electrode performance parameters, high current density discharge evaluation, and low-cost membrane cycle-life performance.

  20. Synthesis of monoclinic zinc diphosphide single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Mowles, T.A.

    1978-05-01

    Monoclinic zinc diphosphide is a cheap, plentiful, direct-gap semiconductor with an optimum transition energy for solar absorption. Single crystals were grown from the vapor to be evaluated as a new photovoltaic material. Monoclinic and tetragonal crystal formed within evacuated quartz ampules that were charged with zinc and excess phosphorous and heated in a temperature gradient to give phosphorous pressures from 0.07 to 8.5 atmospheres. The monoclinic form melts incongruently near 990/sup 0/C. The tetragonal form is metastable; its growth is enhanced by impurities but retarded by high phosphorous pressures. The mechanism of the synthesis indicates that a tightly-controlled vapor deposition is possible and that high-quality thin films should form at temperatures from 950 to 990/sup 0/C at pressures below 10 atmospheres. By a modification of the technique, sesquizinc phosphide single crystals were grown for comparison.

  1. Iron and Zinc Exploitation during Bacterial Pathogenesis

    Science.gov (United States)

    Ma, Li; Terwilliger, Austen; Maresso, Anthony W.

    2016-01-01

    Ancient bacteria originated from metal-rich environments. Billions of years of evolution directed these tiny single cell creatures to exploit the versatile properties of metals in catalyzing chemical reactions and biological responses. The result is an entire metallome of proteins that use metal co-factors to facilitate key cellular process that range from the production of energy to the replication of DNA. Two key metals in this regard are iron and zinc, both abundant on Earth but not readily accessible in a human host. Instead, pathogenic bacteria must employ clever ways to acquire these metals. In this review we describe the many elegant ways these bacteria mine, regulate, and craft the use of two key metals (iron and zinc) to build a virulence arsenal that challenges even the most sophisticated immune response. PMID:26497057

  2. Deletion of the zupT gene for a zinc importer influences zinc pools in Cupriavidus metallidurans CH34.

    Science.gov (United States)

    Herzberg, M; Bauer, L; Nies, D H

    2014-03-01

    Cupriavidus metallidurans strain CH34 accomplishes a high level of transition metal resistance by a combination of rather unspecific transition metal import and controlled efflux of surplus metals. Using the plasmid-free mutant strain AE104 that possesses only a limited number of metal efflux systems, cellular metal pools were identified as counterparts of these transport reactions. At low zinc concentrations strain AE104 took up Zn(II) until the zinc content reached an optimum level of 70,000 Zn(II) per cell in the exponential phase of growth, whereas a ΔzupT mutant lacking the zinc importer ZupT contained only 20,000 Zn(II)/cell, possibly the minimum zinc content. Mutant and parent cells accumulated up to 125,000 Zn(II) per cell at high (100 μM) external zinc concentrations (optimum zinc content). When the mutant strain Δe4, which has all the known genes for zinc efflux systems deleted, was cultivated in the presence of zinc concentrations close to its upper tolerance level (10 μM), these cells contained 250,000 Zn(II) per cell, probably the maximum zinc content. Instead of zinc, 120,000 cobalt or cadmium ions could also fill-up parts of this zinc pool, showing that it is in fact an undefined pool of divalent transition metal cations bound with low substrate specificity. Even when the cells contained sufficient numbers of total zinc, the zinc importer ZupT was required for important cellular processes, indicating the presence of a pool of tightly bound zinc ions, which depends on ZupT for efficient replenishment. The absence of ZupT led to the formation of inclusion bodies, perturbed oxidative stress resistance and decreased efficiency in the synthesis of the zinc-dependent subunit RpoC of the RNA polymerase, leading to RpoC accumulation. Moreover, when a czc allele for a zinc-exporting transenvelope efflux system CzcCBA was constitutively expressed in a ΔzupT mutant, this led to the disappearance of the CzcA protein and the central subunit of the protein

  3. Zinc Oxide Nanostructured Biosensor for Glucose Detection

    Institute of Scientific and Technical Information of China (English)

    X. W.Sun; J.X. Wang; A. Wei

    2008-01-01

    Zinc oxide (ZnO) nanocombs were fabricated by vapor phase transport, and nanorods and hierarchical nanodisk structures by aqueous thermal decomposition. Glucose biosensors were constructed using these ZnO nanostructures as supporting materials for glucose oxidase (GOx) loading. These ZnO glucose biosensors showed a high sensitivity for glucose detection and high affinity of GOx to glucose as well as the low detection limit. The results demonstrate that ZnO nanostructures have potential applications in biosensors.

  4. The Marine Biogeochemistry of Zinc Isotopes

    Science.gov (United States)

    2007-06-01

    dust (Niger) Sapropel (Mediterranean) 4* Deep-Sea Sediments * • Lobster Liver Mussel tissue Plankton Zooplankton Zinc ores * * * Sediment trap material...of natural plankton over large changes in nutrient concentrations in the Peru Upwelling Region. This suggests either that the isotope effect for Zn...hydrothermal fluids and minerals, cultured marine phytoplankton, natural plankton , and seawater. By measuring Zn isotopes in a diverse array of

  5. Impact properties of zinc die cast alloys

    Energy Technology Data Exchange (ETDEWEB)

    Schrems, Karol K.; Dogan, Omer N.; Manahan, M.P. (MPM Technologies, Inc.); Goodwin, F.E. (ILZRO)

    2005-01-01

    Alloys 3, 5, AcuZinc 5, and ZA-8 were tested at five temperatures between -40 C and room temperature to determine impact properties. Izod impact energy data was obtained in accordance with ASTM D256. Unlike ASTM E23, these samples were tested with a milled notch in order to compare with plastic samples. In addition, flexural data was obtained for design use.

  6. Zinc Status of Vegetarians during Pregnancy: A Systematic Review of Observational Studies and Meta-Analysis of Zinc Intake.

    Science.gov (United States)

    Foster, Meika; Herulah, Ursula Nirmala; Prasad, Ashlini; Petocz, Peter; Samman, Samir

    2015-06-05

    Pregnant women are vulnerable to a low zinc status due to the additional zinc demands associated with pregnancy and foetal development. The present systematic review explores the relationship between habitual vegetarian diets and dietary zinc intake/status during pregnancy. The association between vegetarian diets and functional pregnancy outcome also is considered. A literature search was conducted of MEDLINE; PubMed; Embase; the Cochrane Library; Web of Science; and Scopus electronic databases up to September 2014. Six English-language observational studies qualified for inclusion in the systematic review. A meta-analysis was conducted that compared the dietary zinc intake of pregnant vegetarian and non-vegetarian (NV) groups; the zinc intake of vegetarians was found to be lower than that of NV (-1.38 ± 0.35 mg/day; p vegetarian nor NV groups met the recommended dietary allowance (RDA) for zinc. In a qualitative synthesis; no differences were found between groups in serum/plasma zinc or in functional outcomes associated with pregnancy. In conclusion; pregnant vegetarian women have lower zinc intakes than NV control populations and both groups consume lower than recommended amounts. Further information is needed to determine whether physiologic adaptations in zinc metabolism are sufficient to meet maternal and foetal requirements during pregnancy on a low zinc diet.

  7. Effects of Different Zinc Species on Cellar Zinc Distribution, Cell Cycle, Apoptosis and Viability in MDAMB231 Cells.

    Science.gov (United States)

    Wang, Yan-hong; Zhao, Wen-jie; Zheng, Wei-juan; Mao, Li; Lian, Hong-zhen; Hu, Xin; Hua, Zi-chun

    2016-03-01

    Intracellular metal elements exist in mammalian cells with the concentration range from picomoles per litre to micromoles per litre and play a considerable role in various biological procedures. Element provided by different species can influence the availability and distribution of the element in a cell and could lead to different biological effects on the cell's growth and function. Zinc as an abundant and widely distributed essential trace element, is involved in numerous and relevant physiological functions. Zinc homeostasis in cells, which is regulated by metallothioneins, zinc transporter/SLC30A, Zrt-/Irt-like proteins/SLC39A and metal-response element-binding transcription factor-1 (MTF-1), is crucial for normal cellular functioning. In this study, we investigated the influences of different zinc species, zinc sulphate, zinc gluconate and bacitracin zinc, which represented inorganic, organic and biological zinc species, respectively, on cell cycle, viability and apoptosis in MDAMB231 cells. It was found that the responses of cell cycle, apoptosis and death to different zinc species in MDAMB231 cells are different. Western blot analysis of the expression of several key proteins in regulating zinc-related transcription, cell cycle, apoptosis, including MTF-1, cyclin B1, cyclin D1, caspase-8 and caspase-9 in treated cells further confirmed the observed results on cell level.

  8. Neural correlates of consciousness.

    Science.gov (United States)

    Negrao, B L; Viljoen, M

    2009-11-01

    A basic understanding of consciousness and its neural correlates is of major importance for all clinicians, especially those involved with patients with altered states of consciousness. In this paper it is shown that consciousness is dependent on the brainstem and thalamus for arousal; that basic cognition is supported by recurrent electrical activity between the cortex and the thalamus at gamma band frequencies; aand that some kind of working memory must, at least fleetingly, be present for awareness to occur. The problem of cognitive binding and the role of attention are briefly addressed and it shown that consciousness depends on a multitude of subconscious processes. Although these processes do not represent consciousness, consciousness cannot exist without them.

  9. Neural Darwinism and consciousness.

    Science.gov (United States)

    Seth, Anil K; Baars, Bernard J

    2005-03-01

    Neural Darwinism (ND) is a large scale selectionist theory of brain development and function that has been hypothesized to relate to consciousness. According to ND, consciousness is entailed by reentrant interactions among neuronal populations in the thalamocortical system (the 'dynamic core'). These interactions, which permit high-order discriminations among possible core states, confer selective advantages on organisms possessing them by linking current perceptual events to a past history of value-dependent learning. Here, we assess the consistency of ND with 16 widely recognized properties of consciousness, both physiological (for example, consciousness is associated with widespread, relatively fast, low amplitude interactions in the thalamocortical system), and phenomenal (for example, consciousness involves the existence of a private flow of events available only to the experiencing subject). While no theory accounts fully for all of these properties at present, we find that ND and its recent extensions fare well.

  10. Castor bean response to zinc fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Chaves, Lucia Helena Garofalo; Cunha, Tassio Henrique Cavalcanti da Silva; Lima, Vinicius Mota; Cabral, Paulo Cesar Pinto; Barros Junior, Genival; Lacerda, Rogerio Dantas de [Universidade Federal de Campina Grande (UAEAg/UFCG), PB (Brazil). Unidade Academica de Engenharia Agricola

    2008-07-01

    Zinc is a trace element and it is absolutely essential for the normal healthy growth of plants. This element plays a part of several enzyme systems and other metabolic functions in the plants. Castor beans (Ricinus communis L.) crop is raising attention as an alternative crop for oil and biodiesel production. Despite the mineral fertilization is an important factor for increasing castor beans yield, few researches has been made on this issue, mainly on the use of zinc. In order to evaluate the effects of zinc on growth of this plant an experiment was carried out in a greenhouse, in Campina Grande, Paraiba State, Brazil, from July to December 2007. The substrate for the pot plants was a 6 mm-sieved surface soil (Neossolo Quartzarenico). The experimental design was a completely randomized with three replications. The treatments were composed of five levels of Zn (0; 2; 4; 6 and 8 mg dm{sup -3}), which were applied at the time of planting. One plant of castor bean, cultivar BRS 188 - Paraguacu, was grown per pot after thinning and was irrigated whenever necessary. Data on plant height, number and length of leaves and stem diameter were measured at 21, 34, 77 and 103 days after planting. Under conditions that the experiment was carried out the results showed that the Zn levels used, did not affect the castor bean plants growth. (author)

  11. Antioxidant role of zinc in diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    Kyria Jayanne Clímaco Cruz; Ana Raquel Soares de Oliveira; Dilina do Nascimento Marreiro

    2015-01-01

    Chronic hyperglycemia statue noticed in diabetes mellitus favors the manifestation of oxidative stress by increasing the production of reactive oxygen species and/or by reducing the antioxidant defense system activity. Zinc plays an important role in antioxidant defense in type 2 diabetic patients by notably acting as a cofactor of the superoxide dismutase enzyme, by modulating the glutathione metabolism and metallothionein expression, by competing with iron and copper in the cell membrane and by inhibiting nicotinamide adenine dinucleotidephosphate-oxidase enzyme. Zinc also improves theoxidative stress in these patients by reducing chronichyperglycemia. It indeed promotes phosphorylation ofinsulin receptors by enhancing transport of glucose intocells. However, several studies reveal changes in zincmetabolism in individuals with type 2 diabetes mellitusand controversies remain regarding the effect of zincsupplementation in the improvement of oxidative stressin these patients. Faced with the serious challengeof the metabolic disorders related to oxidative stressin diabetes along with the importance of antioxidantnutrients in the control of this disease, new studies maycontribute to improve our understanding of the roleplayed by zinc against oxidative stress and its connectionwith type 2 diabetes mellitus prognosis. This could serveas a prelude to the development of prevention strategiesand treatment of disorders associated with this chronicdisease.

  12. Cadmium and zinc in pregnancy and lactation

    Energy Technology Data Exchange (ETDEWEB)

    Lucis, O.J.; Lucis, R.; Shaikh, Z.A.

    1972-07-01

    Radioactive cadmium (/sup 109/Cd) and zinc (/sup 65/Zn) were injected subcutaneously into pregnant rats. More cadmium than zinc was found in the placentae. After birth, newborns showed detectable /sup 109/Cd only in liver, gastrointestinal tract, and in the brain tissue. Zinc 65 was present in all newborns' tissues. During lactation, highest output of /sup 65/Zn was in colostrum and, on subsequent days, /sup 65/Zn in milk declined rapidly. Cadmium 109 in milk was present in low concentration throughout the lactation period. Rats injected with /sup 109/Cd and /sup 65/Zn after parturition excreted these isotopes in milk in a similiar pattern. Newborns nursed on radioactive milk showed rapid absorption of /sup 65/Zn, whereas /sup 109/Cd accumulated primarily in the intestinal tract; a lesser quantity of /sup 109/Cd was deposited in the liver. In other organs, only /sup 65/Zn was found. The lactating mammary gland contained more /sup 109/Cd than /sup 65/Zn; after lactation, /sup 65/Zn was depleted, whereas /sup 109/Cd remained in mammary tissue.

  13. Chemical treatment of zinc surface and its corrosion inhibition studies

    Indian Academy of Sciences (India)

    S K Rajappa; T V Venkatesha; B M Praveen

    2008-02-01

    The surface treatment of zinc and its corrosion inhibition was studied using a product (BTSC) formed in the reaction between benzaldehyde and thiosemicarbozide. The corrosion behaviour of chemically treated zinc surface was investigated in aqueous chloride–sulphate medium using galvanostatic polarization technique. Zinc samples treated in BTSC solution exhibited good corrosion resistance. The measured electrochemical data indicated a basic modification of the cathode reaction during corrosion of treated zinc. The corrosion protection may be explained on the basis of adsorption and formation of BTSC film on zinc surface. The film was binding strongly to the metal surface through nitrogen and sulphur atoms of the product. The formation of film on the zinc surface was established by surface analysis techniques such as scanning electron microscopy (SEM–EDS) and Fourier transform infrared spectroscopy (FTIR).

  14. Zinc as an adjunct for childhood pneumonia - interpreting early results.

    Science.gov (United States)

    Natchu, Uma Chandra Mouli; Fataki, Maulidi R; Fawzi, Wafaie W

    2008-07-01

    Zinc supplementation has been consistently shown to reduce the incidence of childhood pneumonia, but its effect on the course of pneumonia when administered as an adjunct to antibiotic therapy is still unclear. Three trials published to date have shown mixed results, and a recent trial from India raises the possibility that zinc may be detrimental in some circumstances. Study sites and designs differ, particularly in the timing of zinc treatment and in determining recovery from pneumonia, which can explain the differences in study findings. Serum zinc concentrations are unreliable indicators of zinc status, particularly during acute infectious illnesses. Subgroup analyses, especially using serum zinc levels, must be cautioned against. Future studies are needed that are large enough to be sufficiently powered to accommodate larger treatment failure rates, an issue that ongoing trials will hopefully address.

  15. Plasma in-liquid method for reduction of zinc oxide in zinc nanoparticle synthesis

    Science.gov (United States)

    Amaliyah, Novriany; Mukasa, Shinobu; Nomura, Shinfuku; Toyota, Hiromichi; Kitamae, Tomohide

    2015-02-01

    Metal air-batteries with high-energy density are expected to be increasingly applied in electric vehicles. This will require a method of recycling air batteries, and reduction of metal oxide by generating plasma in liquid has been proposed as a possible method. Microwave-induced plasma is generated in ethanol as a reducing agent in which zinc oxide is dispersed. Analysis by energy-dispersive x-ray spectrometry (EDS) and x-ray diffraction (XRD) reveals the reduction of zinc oxide. According to images by transmission electron microscopy (TEM), cubic and hexagonal metallic zinc particles are formed in sizes of 30 to 200 nm. Additionally, spherical fiber flocculates approximately 180 nm in diameter are present.

  16. First Principles Investigation of Zinc-anode Dissolution in Zinc-air Batteries

    DEFF Research Database (Denmark)

    Siahrostami, Samira; Tripkovic, Vladimir; Lundgård, Keld Troen

    2013-01-01

    With surging interest in high energy density batteries, much attention has recently been devoted to metal-air batteries. The zinc-air battery has been known for more than hundred years and is commercially available as a primary battery, but recharging has remained elusive; in part because...... the fundamental mechanisms still remain to be fully understood. Here, we present a density functional theory investigation of the zinc dissolution (oxidation) on the anode side in the zinc-air battery. Two models are envisaged, the most stable (0001) surface and a kink surface. The kink model proves to be more....... The applied methodology provides new insight into computational modelling and design of secondary metal-air batteries....

  17. Growth mechanisms of zinc oxide and zinc sulfide films by mist chemical vapor deposition

    Science.gov (United States)

    Uno, Kazuyuki; Yamasaki, Yuichiro; Tanaka, Ichiro

    2017-01-01

    The growth mechanisms of zinc oxide and zinc sulfide films by mist chemical vapor deposition (mist-CVD) were experimentally investigated from the viewpoint of mist behaviors and chemical reactions. The proper growth model, either vaporization or the Leidenfrost model, was studied by supplying two kinds of mists with different kinds of sources, such as H2 16O and H2 18O for ZnO growth and ZnCl2 and thiourea for ZnS growth. Moreover, the origin of the oxygen atoms of ZnO was investigated using a quantitative analysis. The role of chloro complex of zinc in the growth of ZnS from aqueous solutions was also examined by systematic studies.

  18. Impact of residual elements on zinc quality in the production of zinc oxide

    Directory of Open Access Journals (Sweden)

    N. Luptáková

    2016-07-01

    Full Text Available The paper is focused on zinc oxide manufacturing process. The present work deals with the character and morphology of the input material for the production of ZnO by the indirect pyrometallurgical process. Undesirable phases in the feedstock can be identified through profound recognition of the source material and the nature of its microstructure. If these compounds diffuse into the lining during thermal processes, they become the cause of stress in metallurgical ceramics. The emergence of these chemical reactions may subsequently affect the entire metallurgical zinc smelting process. The results obtained by analysis are used to minimize waste - zinc slag and to eliminate the conditions which enable the formation of the undesired product, thereby increasing the productivity of the ZnO production.

  19. Deficiencia de zinc y sus implicaciones funcionales Zinc deficiency and its functional implications

    Directory of Open Access Journals (Sweden)

    JORGE L ROSADO

    1998-03-01

    Full Text Available El presente trabajo tiene por objeto revisar los aspectos teóricos y los estudios realizados en México que sugieren la existencia de la deficiencia moderada de zinc en niños de población rural, así como algunas de las consecuencias de dicha deficiencia en la salud. El zinc es un nutrimento indispensable para el organismo de los humanos y juega un papel importante en una serie de procesos metabólicos: participa en el sitio catalítico de varios sistemas enzimáticos; participa como ion estructural en membranas biológicas, y guarda una estrecha relación con la síntesis de proteínas, entre otras cosas. Es por esto que la deficiencia de zinc está asociada con consecuencias importantes en la salud y la funcionalidad de los individuos, especialmente durante las primeras etapas de la vida. De relevancia para México es la existencia de una deficiencia moderada de zinc en los niños y las consecuencias que ésta pueda tener en la salud de los mismos. Los estudios realizados sugieren que la deficiencia moderada de zinc se presenta asociada con la ingestión de dietas basadas en alimentos de origen vegetal, las cuales contienen cantidades importantes de inhibidores de la absorción de zinc. Este tipo de dietas se consume habitualmente en las zonas rurales y en la población marginal de las ciudades en el país. Entre las consecuencias más importantes de esta deficiencia se encontró un aumento en la presencia de enfermedades infecciosas, especialmente de diarrea, y posibles alteraciones en el desarrollo de la capacidad cognoscitiva.The purpose of this article is to review theoretical aspects and research performed in Mexico suggesting the existence of marginal zinc deficiency in rural children and its consequences on health. Zinc is an indispensable nutrient for humans since it plays an important role in several metabolic pathways: it participates in the catalytic site of several enzymes, as a structural ion of biological membranes and is

  20. Artificial Neural Network Analysis System

    Science.gov (United States)

    2007-11-02

    Contract No. DASG60-00-M-0201 Purchase request no.: Foot in the Door-01 Title Name: Artificial Neural Network Analysis System Company: Atlantic... Artificial Neural Network Analysis System 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Powell, Bruce C 5d. PROJECT NUMBER 5e. TASK NUMBER...34) 27-02-2001 Report Type N/A Dates Covered (from... to) ("DD MON YYYY") 28-10-2000 27-02-2001 Title and Subtitle Artificial Neural Network Analysis

  1. Cooperating attackers in neural cryptography.

    Science.gov (United States)

    Shacham, Lanir N; Klein, Einat; Mislovaty, Rachel; Kanter, Ido; Kinzel, Wolfgang

    2004-06-01

    A successful attack strategy in neural cryptography is presented. The neural cryptosystem, based on synchronization of neural networks by mutual learning, has been recently shown to be secure under different attack strategies. The success of the advanced attacker presented here, called the "majority-flipping attacker," does not decay with the parameters of the model. This attacker's outstanding success is due to its using a group of attackers which cooperate throughout the synchronization process, unlike any other attack strategy known. An analytical description of this attack is also presented, and fits the results of simulations.

  2. The zinc finger protein ZNF658 regulates the transcription of genes involved in zinc homeostasis and affects ribosome biogenesis through the zinc transcriptional regulatory element.

    Science.gov (United States)

    Ogo, Ogo A; Tyson, John; Cockell, Simon J; Howard, Alison; Valentine, Ruth A; Ford, Dianne

    2015-03-01

    We previously identified the ZTRE (zinc transcriptional regulatory element) in genes involved in zinc homeostasis and showed that it mediates transcriptional repression in response to zinc. We now report that ZNF658 acts at the ZTRE. ZNF658 was identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry of a band excised after electrophoretic mobility shift assay using a ZTRE probe. The protein contains a KRAB domain and 21 zinc fingers. It has similarity with ZAP1 from Saccharomyces cerevisiae, which regulates the response to zinc restriction, including a conserved DNA binding region we show to be functional also in ZNF658. Small interfering RNA (siRNA) targeted to ZNF658 abrogated the zinc-induced, ZTRE-dependent reduction in SLC30A5 (ZnT5 gene), SLC30A10 (ZnT10 gene), and CBWD transcripts in human Caco-2 cells and the ability of zinc to repress reporter gene expression from corresponding promoter-reporter constructs. Microarray analysis of the effect of reducing ZNF658 expression by siRNA uncovered a large decrease in rRNA. We find that ZTREs are clustered within the 45S rRNA precursor. We also saw effects on expression of multiple ribosomal proteins. ZNF658 thus links zinc homeostasis with ribosome biogenesis, the most active transcriptional, and hence zinc-demanding, process in the cell. ZNF658 is thus a novel transcriptional regulator that plays a fundamental role in the orchestrated cellular response to zinc availability.

  3. Jiangxi Copper Marching into Lead-zinc Industry

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>On November 13,Jiangxi Copper officially signed transfer agreement on the share rights of lead-zinc mines with Jiangxi Provincial Geol- ogy & Mineral Resources Bureau,marking the beginning of full-strategic cooperation between the two parties for the common exploitation of lead-zinc industry in the province. The Jiangxi Province is rich in lead-zinc re- sources,but most of them are in scattered lay-

  4. Effects of Zinc Chelators on Aflatoxin Production in Aspergillus parasiticus

    Science.gov (United States)

    Wee, Josephine; Day, Devin M.; Linz, John E.

    2016-01-01

    Zinc concentrations strongly influence aflatoxin accumulation in laboratory media and in food and feed crops. The presence of zinc stimulates aflatoxin production, and the absence of zinc impedes toxin production. Initial studies that suggested a link between zinc and aflatoxin biosynthesis were presented in the 1970s. In the present study, we utilized two zinc chelators, N,N,N′,N′-tetrakis (2-pyridylmethyl) ethane-1,2-diamine (TPEN) and 2,3-dimercapto-1-propanesulfonic acid (DMPS) to explore the effect of zinc limitation on aflatoxin synthesis in Aspergillus parasiticus. TPEN but not DMPS decreased aflatoxin biosynthesis up to six-fold depending on whether A. parasiticus was grown on rich or minimal medium. Although we observed significant inhibition of aflatoxin production by TPEN, no detectable changes were observed in expression levels of the aflatoxin pathway gene ver-1 and the zinc binuclear cluster transcription factor, AflR. Treatment of growing A. parasiticus solid culture with a fluorescent zinc probe demonstrated an increase in intracellular zinc levels assessed by increases in fluorescent intensity of cultures treated with TPEN compared to controls. These data suggest that TPEN binds to cytoplasmic zinc therefore limiting fungal access to zinc. To investigate the efficacy of TPEN on food and feed crops, we found that TPEN effectively decreases aflatoxin accumulation on peanut medium but not in a sunflower seeds-derived medium. From an application perspective, these data provide the basis for biological differences that exist in the efficacy of different zinc chelators in various food and feed crops frequently contaminated by aflatoxin. PMID:27271668

  5. HYDROTHERMAL SYNTHESIS OF NANO-METER MICROPOROUS ZINC FERRITE

    Institute of Scientific and Technical Information of China (English)

    Xiaoling Hu; Ping Guan; Xin Yan

    2004-01-01

    Nano-meter microporous zinc ferrite was prepared by a hydrothermal method, using triethylamine as a template. Adsorption curves showed that the product had a microporous structure. The effects of precursor pH, reaction temperature and reaction time on the preparation were studied, yielding optimal conditions: pH=11,448 K, 360 min. The morphology of zinc ferrite as observed by TEM, showed that zinc ferrite was well-crystallized and well-dispersed with little conglomeration.

  6. Zinc glycine chelate absorption characteristics in Sprague Dawley rat.

    Science.gov (United States)

    Yue, M; Fang, S L; Zhuo, Z; Li, D D; Feng, J

    2015-06-01

    This study was conducted to investigate absorption characteristics of zinc glycine chelate (Zn-Gly) by evaluating tissues zinc status and the expression of zinc transporters in rats. A total of 24 male rats were randomly allocated to three treatments and administered either saline or 35 mg Zn/kg body weight from zinc sulphate (ZnSO4 ) or Zn-Gly by feeding tube separately. Four rats per group were slaughtered and tissues were collected at 2 and 6 h after gavage respectively. Our data showed that Zn-Gly did more effectively in increasing (p < 0.05) serum zinc levels, and the activities of serum and liver alkaline phosphatase (ALP) and liver Cu/Zn superoxide dismutase (Cu/Zn SOD) at 2 and 6 h. By 2 h after the zinc load, the mRNA and protein abundance of intestinal metallothionein1 (MT1) and zinc transporter SLC30A1 (ZnT1) were higher (p < 0.05), and zinc transporter SLC39A4 (Zip4) lower (p < 0.05) in ZnSO4 compared to other groups. Zinc transporter SLC39A5 (Zip5) mRNA expression was not zinc responsive, but Zip5 protein abundance was remarkably (p < 0.05) increased in ZnSO4 2 h later. Overall, our results indicated that in short-term periods, Zn-Gly was more effective in improving body zinc status than ZnSO4 , and ZnSO4 did more efficiently on the regulation of zinc transporters in small intestine.

  7. Zinc and Diarrheal Disease: Current Status and Future Perspectives

    Science.gov (United States)

    2008-01-01

    therapy (ORS) has dramatically reduced mortality from dehydration caused by diarrhea - estimates of global mortality from diarrhea declined from...arc approximately 2.8 million Giardia Imnbliil infections per year. Recurrent asymptomatic and symptom~llic infec- tions by these and other...effects of zinc, not zinc· replacement therapy , as they also occur in the absence of zinc deficiency. Cholera is a common disease in many countries of

  8. HUBUNGAN ANTARA ZINC SERUM DENGAN STATUS GIZI LANSIA

    Directory of Open Access Journals (Sweden)

    Fitrah Emawati

    2012-11-01

    Full Text Available RELATIONSHIP BETWEEN ZINC SERUM AND NUTRITIONAL STATUS OF ELDERLY PEOPLE.Background: The findings of study that 30% in Bogor and 27% in Jakarta of elderly people were undernourished. Malnutrition may occur due to infection and low food intake. Among elderly people, one of the factors that causes low food intake is affected by impairment of taste sensory and teeth function. The impairment of taste sensory is influenced by zinc status in the body.Objective: To collect food consumption pattem data of zinc rich foods, zinc concentration in serum and to analyze association of zinc concentration and nutritional status.Methods: Research design was cross sectional, and conducted in two sub districts in Bogor city. The respondents were women in 60-75 years of age, no suffering from illnesses and chronically disease. The total respondent was 90 people, and divided into three groups of 30 peoples. Data gathered included respondent identity, physical examination, anthropometry, blood biochemical and zinc dietary consumption.Results: Zinc dietary consumption adequacy of underweight group was only 30% of recommended dietary allowance, while for normal and overweight groups were 40% of dietary allowance. Zinc serum concentration of underweight group (82 ug/dl was not significantly different with normal group (85 ug/dl, however differed significantly (p<0.05 with overweight group (95 ug/dl. Underweight group suffered 40% zinc deficiency, 27% for normal and only 7% for overweight group.Conclusions: Zinc deficiency was more prevalent in underweight group than that of normal and overweight group. [Panel Gizi Makan 2002,25: 26-33.Keywords: zinc serum concentration, zinc dietary consumption, underweight

  9. Zinc: Role in the management of diarrhea and cholera

    OpenAIRE

    Qadir, M Imran; Arshad, Arfa; Ahmad, Bashir

    2013-01-01

    Diarrhea and cholera are major health problems. Vibrio cholera, the causative agent of cholera, infects the small intestine, resulting in vomiting, massive watery diarrhea and dehydration. Reduced water and electrolyte absorption is also due to zinc deficiency. Zinc has an important role in recovery from the disease. The combination of zinc with cholera vaccine and oral rehydration solutions has a positive impact on cholera and diarrhea. It has led to a decrease in the mortality and morbidity...

  10. Quantitative recognition of flammable and toxic gases with artificial neural network using metal oxide gas sensors in embedded platform

    Directory of Open Access Journals (Sweden)

    B. Mondal

    2015-06-01

    Full Text Available Artificial Neural Network (ANN based pattern recognition technique is used for ensuring the reliable evaluation of responses from an array of Zinc Oxide (ZnO based sensors comprising of pure ZnO nano-rods and composites of ZnO–SnO2. All the sensors were fabricated in the lab. The paper first reports the development of an artificial neural network based model for successfully recognizing different concentration of hydrogen, methane and carbon mono-oxide. Feed forward back propagation neural network was used for the classification of the gases at critical concentrations. The optimized ANN algorithm is then embedded in the microcontroller based circuit and finally verified under lab conditions.

  11. Toxic effect of zinc nanoscale metal-organic frameworks on rat pheochromocytoma (PC12) cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Fei, E-mail: paper_mail@126.com [Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Yang, Baochun; Cai, Jing [Department of Pharmacy, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Jiang, Yaodong [Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Xu, Jun [Department of Health Economy Administration, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Wang, Shan [Department of Pharmacy, Winthrop University Hospital, Mineola, NY 11501 (United States)

    2014-04-01

    Highlights: • Metal-organic frameworks (MOFs) represent a newborn family of hybrid materials. • MOFs have already shown promise in a number of biological applications. • The biological applications of MOFs raise concerns for potential cytotoxicity. • Substantial information about MOF's neurotoxicity is still quite scarce. • This study reveals for the first time the interaction of MOFs with neural cells. - Abstract: Metal-organic frameworks (MOFs) possess unique properties desirable for delivery of drugs and gaseous therapeutics, but their uncharacterized interactions with cells raise increasing concerns of their safety in such biomedical applications. We evaluated the adverse effects of zinc nanoscale MOFs on the cell morphology, cytoskeleton, cell viability and expression of neurotrophin signaling pathway-associated GAP-43 protein in rat pheochromocytoma PC12 cells. At the concentration of 25 μg/ml, zinc MOFs did not significantly affect morphology, viability and membrane integrity of the cells. But at higher concentrations (over 100 μg/ml), MOFs exhibited a time- and concentration-dependent cytotoxicity, indicating their entry into the cells via endocytosis where they release Zn{sup 2+} into the cytosol to cause increased intracellular concentration of Zn{sup 2+}. We demonstrated that the toxicity of MOFs was associated with a disrupted cellular zinc homeostasis and down-regulation of GAP-43 protein, which might be the underlying mechanism for the improved differentiation in PC12 cells. These findings highlight the importance of cytotoxic evaluation of the MOFs before their biomedical application.

  12. Role of zinc and zinc transporters in the molecular pathogenesis of diabetes mellitus.

    Science.gov (United States)

    Quraishi, Iram; Collins, Sibrina; Pestaner, Joseph P; Harris, Twaina; Bagasra, Omar

    2005-01-01

    Diabetes is one of the most common chronic diseases in the United States. An estimated 18.2 million people in the US (6.3%) have diabetes; among them 2.8 million are African Americans (AAs). On average, AAs are twice as likely to have diabetes as European Americans (EAs) of similar age. AAs disproportionately suffer from various diseases in the US. Many of these diseases include hypertension, cardiovascular disease (CVD), diabetes mellitus (DM-beta predominantly Type II), and cancers of the prostate and pancreas. A number of risk factors such as smoking, a high fat diet, little physical activity, stress, and meager access to health care have been the subject of numerous investigations. However, the factor of the interaction between genetics and the environment has received very little attention in the scientific community. Of note, the content of zinc in pancreatic beta gells is among the highest in the body; however, very little is known about the uptake and storage of zinc inside these cells. We hypothesize that one of the major reason AAs disproportionally suffer from DM (as well as some other illnesses like prostate cancer, CVD and hypertension) is due to their inherent inability to transport appropriate amount of zinc in the crucial cell types that require relatively higher amount of zinc than the other cell types. In this article, we will explore in detail the possible genetic and environmental link between human zinc transporters (hZIPs) and their differential expressions in the islet beta cells from AAs as compared to other racial groups, particularly EAs, in both normal healthy individuals and diabetic patients. We hypothesize that the hZIPs play an important role in the development of diabetes, and the main reason AAs disproportionately suffer from DM (as well as other illnesses like prostate and pancreatic cancers, hypertension, and CVD) as compared to EAs may be due the low degree of expressions of the critical zinc transporters in the beta cells

  13. Dietary polyphenols display zinc ionophore activity and modulate zinc signaling in hepatocarcinoma cells

    OpenAIRE

    2015-01-01

    El zinc es el metal de transición más abundante después del hierro en todas las células, y un micronutriente esencial, presentando diversas funciones en sistemas biológicos. Por otra parte, los polifenoles de la dieta son micronutrientes bioactivos que muestran numerosos beneficios para la salud, tales como actividad antitumoral y neuroprotectora. Anteriores trabajos de nuestro grupo de investigación han demostrado que los polifenoles interaccionan con cationes de zinc y tienen la capacidad d...

  14. Zinc-induced oligomerization of zinc α2 glycoprotein reveals multiple fatty acid-binding sites

    OpenAIRE

    Zahid, Henna; Miah, Layeque; Lau, Andy; Brochard, Lea; Hati, Debolina; Bui, T. T.; Drake, A. F.; Gor, Jayesh; Perkins, Stephen J.; McDermott, Lindsay C.

    2016-01-01

    Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigate...

  15. Evaluation of atmospheric corrosion on electroplated zinc and zinc nickel coatings by Electrical Resistance (ER) Monitoring

    DEFF Research Database (Denmark)

    Møller, Per

    2013-01-01

    ER (Electrical Resistance) probes provide a measurement of metal loss, measured at any time when a metal is exposed to the real environment. The precise electrical resistance monitoring system can evaluate the corrosion to the level of nanometers, if the conductivity is compensated for temperature...... and magnetic fields. With this technique very important information about the durability of a new conversion coatings for aluminum, zinc and zinc alloys exposed to unknown atmospheric conditions can be gathered. This is expected to have a major impact on a number of industrial segments, such as test cars...

  16. Morphogenetic movements in the neural plate and neural tube: mouse.

    Science.gov (United States)

    Massarwa, R'ada; Ray, Heather J; Niswander, Lee

    2014-01-01

    The neural tube (NT), the embryonic precursor of the vertebrate brain and spinal cord, is generated by a complex and highly dynamic morphological process. In mammals, the initially flat neural plate bends and lifts bilaterally to generate the neural folds followed by fusion of the folds at the midline during the process of neural tube closure (NTC). Failures in any step of this process can lead to neural tube defects (NTDs), a common class of birth defects that occur in approximately 1 in 1000 live births. These severe birth abnormalities include spina bifida, a failure of closure at the spinal level; craniorachischisis, a failure of NTC along the entire body axis; and exencephaly, a failure of the cranial neural folds to close which leads to degeneration of the exposed brain tissue termed anencephaly. The mouse embryo presents excellent opportunities to explore the genetic basis of NTC in mammals; however, its in utero development has also presented great challenges in generating a deeper understanding of how gene function regulates the cell and tissue behaviors that drive this highly dynamic process. Recent technological advances are now allowing researchers to address these questions through visualization of NTC dynamics in the mouse embryo in real time, thus offering new insights into the morphogenesis of mammalian NTC.

  17. Cadmium and zinc relationships in kidney cortex, liver, and pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Elinder, C.G.; Piscator, M.; Linnman, L.

    1977-06-01

    Zinc and cadmium have been determined in kidney cortex, liver, and pancreas from 292 subjects autopsied in Stockholm, Sweden. In the liver and pancreas zinc was found to have a normal frequency distribution, average 45.3 ..mu..g/g and 26.9 ..mu..g/g wet wt, respectively. The concentrations of zinc in these two organs were constant regardless of age at death. Zinc was shown to accumulate with age in the kidney cortex in a way similar to cadmium, and had a log-normal distribution. The calculation of the regression line between individual cadmium concentrations below 60 ..mu..g/g and zinc concentrations gave a slope constant of 0.61 (Y/sub Zn/ = 0.61 X/sub Cd/ + 24.4), which corresponds to a nearly equimolar increase of zinc. The concentrations of ''physiological zinc,'' i.e., total zinc minus the zinc related to cadmium, were normally distributed (anti x = 24.6 ..mu..g Zn/g) and did not change with age. Furthermore, data on dry weight/wet weight ratios and ash weight/dry weight ratios in relation to age are presented.

  18. Trophic skin ulceration of leprosy: skin and serum zinc concentrations.

    Science.gov (United States)

    Oon, B B; Khong, K Y; Greaves, M W; Plummer, V M

    1974-06-08

    Skin and serum zinc measurements have been made in patients with leprosy with and without trophic skin ulceration and in several other groups. Serum zinc concentrations were decreased in leprosy irrespective of the presence or absence of skin ulceration. Serum zinc concentrations in leprosy were also unrelated to smears positive for Mycobacterium leprae and to the clinical type of leprosy. Since a decrease of the serum zinc was also found in patients with dermatitis herpetiformis and pulmonary tuberculosis it seems likely that the decreased serum zinc in leprosy is a nonspecific metabolic consequence of chronic skin and internal disease. The mean skin zinc concentration in leprosy did not differ significantly from the corresponding value in control subjects, the lack of agreement between serum and skin concentrations being possibly related to the presence of nonexchangeable keratin-bound zinc in skin. Though the clinical significance of lowered serum zinc concentrations in leprosy is uncertain therapeutic trials of zinc treatment in leprosy with trophic skin ulceration seem justifiable.

  19. Phytic acid reduction in soy protein improves zinc bioavailability

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, J.R.; Wong, M.S.; Burns, R.A.; Erdman, J.W. Jr. (Univ. of Illinois, Urbana (United States) Mead Johnson Research Center, Evansville, IN (United States))

    1991-03-15

    The objective of this study was to confirm previous studies that have suggested that reduction of phytic acid in soy improved zinc bioavailability (BV). Two commercially-produced soybean isolates containing either a normal phytic acid level or a reduced level were formulated into diets so as to provide 6 or 9 ppm zinc. Control diets were egg white protein-based and contained 3, 6 or 9 ppm zinc from zinc carbonate. Weanling male rats were fed these diets for 21 days and food intake and weight gain monitored. Slope ratio analysis of total tibia zinc content compared to total zinc intake revealed that zinc BV from reduced phytic acid soy isolate-containing diets was indistinguishable from control egg white diets. In contrast, zinc BV from normal soy isolate diets was significantly reduced compared to reduced phytic acid and control diets. These results coupled with other results indicate that phytic acid is the inhibitory factor in soybean products that results in reduced zinc BV.

  20. Zinc as Allosteric Ion Channel Modulator: Ionotropic Receptors as Metalloproteins

    Science.gov (United States)

    Peralta, Francisco Andrés; Huidobro-Toro, Juan Pablo

    2016-01-01

    Zinc is an essential metal to life. This transition metal is a structural component of many proteins and is actively involved in the catalytic activity of cell enzymes. In either case, these zinc-containing proteins are metalloproteins. However, the amino acid residues that serve as ligands for metal coordination are not necessarily the same in structural proteins compared to enzymes. While crystals of structural proteins that bind zinc reveal a higher preference for cysteine sulfhydryls rather than histidine imidazole rings, catalytic enzymes reveal the opposite, i.e., a greater preference for the histidines over cysteines for catalysis, plus the influence of carboxylic acids. Based on this paradigm, we reviewed the putative ligands of zinc in ionotropic receptors, where zinc has been described as an allosteric modulator of channel receptors. Although these receptors do not strictly qualify as metalloproteins since they do not normally bind zinc in structural domains, they do transitorily bind zinc at allosteric sites, modifying transiently the receptor channel’s ion permeability. The present contribution summarizes current information showing that zinc allosteric modulation of receptor channels occurs by the preferential metal coordination to imidazole rings as well as to the sulfhydryl groups of cysteine in addition to the carboxyl group of acid residues, as with enzymes and catalysis. It is remarkable that most channels, either voltage-sensitive or transmitter-gated receptor channels, are susceptible to zinc modulation either as positive or negative regulators. PMID:27384555

  1. Zinc Modulates Nanosilver-Induced Toxicity in Primary Neuronal Cultures.

    Science.gov (United States)

    Ziemińska, Elżbieta; Strużyńska, Lidia

    2016-02-01

    Silver nanoparticles (NAg) have recently become one of the most commonly used nanomaterials. Since the ability of nanosilver to enter the brain has been confirmed, there has been a need to investigate mechanisms of its neurotoxicity. We previously showed that primary neuronal cultures treated with nanosilver undergo destabilization of calcium homeostasis via a mechanism involving glutamatergic NMDA receptors. Considering the fact that zinc interacts with these receptors, the aim of the present study was to examine the role of zinc in mechanisms of neuronal cell death in primary cultures. In cells treated with nanosilver, we noted an imbalance between extracellular and intracellular zinc levels. Thus, the influence of zinc deficiency and supplementation on nanosilver-evoked cytotoxicity was investigated by treatment with TPEN (a chelator of zinc ions), or ZnCl(2), respectively. Elimination of zinc leads to complete death of nanosilver-treated CGCs. In contrast, supplementation with ZnCl(2) increases viability of CGCs in a dose-dependent manner. Addition of zinc provided protection against the extra/intracellular calcium imbalance in a manner similar to MK-801, an antagonist of NMDA receptors. Zinc chelation by TPEN decreases the mitochondrial potential and dramatically increases the rate of production of reactive oxygen species. Our results indicate that zinc supplementation positively influences nanosilver-evoked changes in CGCs. This is presumed to be due to an inhibitory effect on NMDA-sensitive calcium channels.

  2. Influence of Cortisol on zinc metabolism in morbidly obese women

    Directory of Open Access Journals (Sweden)

    Luana Mota Martins

    2014-01-01

    Full Text Available Introduction: The accumulation of visceral fat affects the metabolism of hormones and some nutrients, but these mechanisms remain unclear. Objective: To assess the influence of cortisol on the metabolism of zinc in morbidly obese women. Method: Cross-sectional, case-control study involving 80 women aged between 20 and 59 years. The participants were divided into two groups: experimental (morbidly obese, n = 40 and control (normal weight, n = 40. Zinc concentrations were determined by atomic absorption spectroscopy and serum and urinary cortisol by chemiluminescence method. Results: Zinc intake was significantly different between groups. Mean plasma zinc was lower in obese compared to control group. Mean values for erythrocyte zinc were 44.52 ± 7.84 μg/gHb and 40.17 ± 6.71 μg/gHb for obese and control groups, respectively. Urinary excretion of this mineral was higher in obese compared to control subjects (p 0.05. The correlation analysis between cortisol and zinc was not significant (p > 0.05. Conclusions: Obese patients have hypozincemia and high erythrocyte zinc levels. The correlation between zinc parameters and cortisol concentration showed no influence of this hormone on zinc metabolism.

  3. Zinc as Allosteric Ion Channel Modulator: Ionotropic Receptors as Metalloproteins

    Directory of Open Access Journals (Sweden)

    Francisco Andrés Peralta

    2016-07-01

    Full Text Available Zinc is an essential metal to life. This transition metal is a structural component of many proteins and is actively involved in the catalytic activity of cell enzymes. In either case, these zinc-containing proteins are metalloproteins. However, the amino acid residues that serve as ligands for metal coordination are not necessarily the same in structural proteins compared to enzymes. While crystals of structural proteins that bind zinc reveal a higher preference for cysteine sulfhydryls rather than histidine imidazole rings, catalytic enzymes reveal the opposite, i.e., a greater preference for the histidines over cysteines for catalysis, plus the influence of carboxylic acids. Based on this paradigm, we reviewed the putative ligands of zinc in ionotropic receptors, where zinc has been described as an allosteric modulator of channel receptors. Although these receptors do not strictly qualify as metalloproteins since they do not normally bind zinc in structural domains, they do transitorily bind zinc at allosteric sites, modifying transiently the receptor channel’s ion permeability. The present contribution summarizes current information showing that zinc allosteric modulation of receptor channels occurs by the preferential metal coordination to imidazole rings as well as to the sulfhydryl groups of cysteine in addition to the carboxyl group of acid residues, as with enzymes and catalysis. It is remarkable that most channels, either voltage-sensitive or transmitter-gated receptor channels, are susceptible to zinc modulation either as positive or negative regulators.

  4. Copper and zinc concentrations in serum of healthy Greek adults

    Energy Technology Data Exchange (ETDEWEB)

    Kouremenou-Dona, Eleni [A' Hospital of IKA, Athens (Greece); Dona, Artemis [Department of Forensic Medicine and Toxicology, Medical School, University of Athens, M. Asias 75, Goudi, 11527 Athens (Greece)]. E-mail: artedona@med.uoa.gr; Papoutsis, John [Department of Forensic Medicine and Toxicology, Medical School, University of Athens, M. Asias 75, Goudi, 11527 Athens (Greece); Spiliopoulou, Chara [Department of Forensic Medicine and Toxicology, Medical School, University of Athens, M. Asias 75, Goudi, 11527 Athens (Greece)

    2006-04-15

    Serum copper and zinc concentrations of 506 (414 males and 92 females) apparently healthy Greek blood donors aged 18-60 years old were determined by flame atomic absorption spectrometry. The mean copper and zinc concentrations were 115.46 {+-} 23.56 {mu}g/dl and 77.11 {+-} 17.67 {mu}g/dl, respectively. The mean value for copper and zinc in females was higher than in males, although the difference for zinc was smaller than the one observed for copper. When the subjects were divided into various age groups there appeared to be some increase in copper concentration as a function of age, whereas zinc concentration did not change. There were no significant variations in serum copper and zinc concentrations due to place of residence, occupation and socioeconomic status. This study is the first one evaluating the serum status of copper and zinc in healthy Greeks and it has shown that they are at the highest concentration range for copper and the lowest for zinc compared to literature data on copper and zinc levels for various countries.

  5. Zinc content of maturing spermatozoa in oestrogen treated rats.

    Science.gov (United States)

    Srivastava, A; Chowdhury, A R; Setty, B S

    1983-02-01

    Zinc content of spermatozoa collected from the caput and cauda portions of the rat epididymis was determined by atomic absorption spectroscopy. The results showed about 60% reduction in the spermatozoal zinc content by the time they reach the cauda epididymis. This reduction was inhibited in rats receiving micro dose oestrogen which induced 'functional' sterility. It appears that the fall in zinc content of spermatozoa during their transport in the epididymis is related to sperm maturation and that oestrogen treatment interferes with this reduction in sperm zinc content.

  6. Effect of Zinc Toxicity on Lymphoid Organs in Chickens

    Institute of Scientific and Technical Information of China (English)

    CUI Heng-min; ZHAO Cui-yan; LI De-bing; PENG Xi; DENG Jun-liang

    2004-01-01

    The experiment was conducted with the objective of studies on effects of zinc toxicity on lymphoid organs by the methods of experimental pathology and flow cytometry (FCM). 200one-day-old Avian broilers were divided into four groups randomly, and fed on diets as follows: controls (Zn 100mg kg-1)and zinc toxic (Zn 1 500mg kg-1, zinc toxic group Ⅰ; Zn 2 000 mg kg-1, zinc toxic group Ⅱ; Zn 2 500 mg kg-1, zinc toxic group Ⅲ) for seven weeks. The weight and growth index of the thymus, spleen and bursa of Fabricius were reduced in both zinc toxic group Ⅱ and zinc toxic group Ⅲ when compared with those of control group. The G0/G1 phase of the cell cycles of the lymphoid organs was higher, and S, G2+M phases lower in zinc toxic groups Ⅱ and Ⅲ than in control group. Lymphocytes were depleted and degenerate in the lymphoid organs. The reticular cells of the bursa of Fabricius proliferated and the reticular cells of the thymus were also degenerate and necrotic,particularly in zinc toxic groups Ⅱ and Ⅲ. The results demonstrated that more than 1 500 mg kg-1 impaired the progression of lymphocytes from the G0/G1 phase to S phase obviously, inhibited the development of lymphoid organs and caused marked pathological changes in the lymphoid organs. Potential mechanisms underlying these observations are also discussed.

  7. Anti-ulcer and membrane stabilizing actions of zinc acexamate.

    Science.gov (United States)

    Pfeiffer, C J; Bulbena, O; Esplugues, J V; Escolar, G; Navarro, C; Esplugues, J

    1987-01-01

    The effects of zinc acexamate on stress and reserpine ulcers as well as on gastric mast cells degranulation and membrane stability were evaluated in the rat. Zinc acexamate (100 mg/kg) has demonstrated an inhibitory effect on cold-restraint stress and reserpine-induced ulcer in a dose-dependent manner. Pretreatment of rats, prior to cold restraint stress, reduced gastric mast cell degranulation. Zinc acexamate (10(-4) M) inhibits Triton X-100 release of beta-glucuronidase in isolated hepatic lysosomes. These observations suggest that ulcer protective actions of zinc acexamate may be exerted in part through enhancing gastric mucosal resistance by stabilizing biological membrane integrity.

  8. Intensification of zinc dissolution process in sulphuric acid

    Directory of Open Access Journals (Sweden)

    Stanojević D.

    2005-01-01

    Full Text Available Many high purity salts are produced by dissolving pure metal in non-oxidizing mineral acids. If hydrogen overpotential on the given metal is high, then the rate of overall process is defined by reaction of hydrogen ion reduction. This study investigated the possibility of accelerated dissolving of metal zinc in sulphuric acid by introducing copper cathode on which evolving hydrogen is much easier than on zinc. It was found out that the acceleration of zinc dissolving is possible and, at constant surface of copper cathode depends on the quality of electrical contact between copper electrode and zinc.

  9. Abnormalities of zinc and copper during total parenteral nutrition.

    Science.gov (United States)

    Lowry, S F; Goodgame, J T; Smith, J C; Maher, M M; Makuch, R W; Henkin, R I; Brennan, M F

    1979-01-01

    Changes in serum zinc and copper levels were studied in 19 tumor bearing patients undergoing parenteral nutrition (TPN) for five to 42 days. Before initiation of intravenous feeding mean serum zinc and copper concentrations were within normal limits but during TPN levels decreased significantly below those measured prior to parenteral nutrition. During TPN nitrogen, zinc, and copper intake, urinary output and serum levels were studied prospectively in nine of these patients. These nine patients exhibited positive nitrogen retention based upon urinary nitrogen excretion, but elevated urinary zinc and copper excretion and lowered serum zinc and copper concentrations. Neither blood administration nor limited oral intake was consistently able to maintain normal serum levels of zinc or copper. Zinc and copper supplementation of hyperalimentation fluids in four patients studied for five to 16 days was successful in increasing serum zinc and copper levels in only two. The data obtained suggest that patients undergoing parenteral nutrition may require supplementation of zinc and copper to prevent deficiencies of these elements. PMID:103506

  10. Differences in zinc status between patients with osteoarthritis and osteoporosis

    DEFF Research Database (Denmark)

    Ovesen, Janne; Møller-Madsen, Bjarne; Nielsen, Poul Torben

    2009-01-01

    Zinc has been suggested to play an important role in the development of osteoporosis, whereas the influence of zinc on osteoarthritis has attracted much less attention. The aim of the study was to investigate and compare the zinc status and bone turnover, density, and biomechanical properties...... of osteoarthritic and osteoporotic patients. The study comprised 40 women who underwent hip replacement due to osteoarthritis or osteoporosis. Serum and urine zinc content, and bone resorption markers and serum bone formation markers were determined. The unaffected hip and the exarticulated affected femoral head...... that osteoporosis and osteoarthritis rarely occur in the same individual....

  11. Behavioral impairments in animal models for zinc deficiency

    Directory of Open Access Journals (Sweden)

    Simone eHagmeyer

    2015-01-01

    Full Text Available Apart from teratogenic and pathological effects of zinc deficiency such as the occurrence of skin lesions, anorexia, growth retardation, depressed wound healing, altered immune function, impaired night vision, and alterations in taste and smell acuity, characteristic behavioral changes in animal models and human patients suffering from zinc deficiency have been observed. Given that it is estimated that about 17% of the worldwide population are at risk for zinc deficiency and that zinc deficiency is associated with a variety of brain disorders and disease states in humans, it is of major interest to investigate, how these behavioral changes will affect the individual and a putative course of a disease. Thus, here, we provide a state of the art overview about the behavioral phenotypes observed in various models of zinc deficiency, among them environmentally produced zinc deficient animals as well as animal models based on a genetic alteration of a particular zinc homeostasis gene. Finally, we compare the behavioral phenotypes to the human condition of mild to severe zinc deficiency and provide a model, how zinc deficiency that is associated with many neurodegenerative and neuropsychological disorders might modify the disease pathologies.

  12. Benefits and drawbacks of zinc in glass ionomer bone cements

    Energy Technology Data Exchange (ETDEWEB)

    Brauer, Delia S; Hill, Robert G [Unit of Dental Physical Sciences, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Gentleman, Eileen; Stevens, Molly M [Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Farrar, David F, E-mail: d.brauer@qmul.ac.uk [Smith and Nephew Research Centre, York Science Park, Heslington YO10 5DF (United Kingdom)

    2011-08-15

    Glass polyalkenoate (ionomer) cements (GPCs) based on poly(acrylic acid) and fluoro-alumino-silicate glasses are successfully used in a variety of orthopaedic and dental applications; however, they release small amounts of aluminium, which is a neurotoxin and inhibits bone mineralization in vivo. Therefore there has been significant interest in developing aluminium-free glasses containing zinc for forming GPCs because zinc can play a similar structural role in the glass, allowing for glass degradation and subsequent cement setting, and is reported to have beneficial effects on bone formation. We created zinc-containing GPCs and characterized their mechanical properties and biocompatibility. Zinc-containing cements showed adhesion to bone close to 1 MPa, which was significantly greater than that of zinc-free cements (<0.05 MPa) and other currently approved biological adhesives. However, zinc-containing cements produced significantly lower metabolic activity in mouse osteoblasts exposed to cell culture medium conditioned with the cements than controls. Results show that although low levels of zinc may be beneficial to cells, zinc concentrations of 400 {mu}M Zn{sup 2+} or more resulted in cell death. In summary, we demonstrate that while zinc-containing GPCs possess excellent mechanical properties, they fail basic biocompatibility tests, produce an acute cytotoxic response in vitro, which may preclude their use in vivo.

  13. Impact of high dietary zinc on zinc accumulation, enzyme activity and proteomic profiles in the pancreas of piglets.

    Science.gov (United States)

    Pieper, R; Martin, L; Schunter, N; Villodre Tudela, C; Weise, C; Klopfleisch, R; Zentek, J; Einspanier, R; Bondzio, A

    2015-04-01

    The exocrine pancreas plays an important role in zinc homeostasis. Feeding very high (2000-3000mgzinc/kg diet) levels of zinc oxide to piglets for short periods is a common practice in the swine industry to improve performance and prevent diseases. The impact on pancreatic function and possible side effects during long-term feeding of high dietary zinc levels are still poorly understood. A total of 54 weaned piglets were either fed with low (57mg/kg, LZn), normal (164mg/kg, NZn) or high (2425mg/kg, HZn) zinc concentration in the diets. After 4 weeks of feeding, ten piglets per treatment were euthanized and pancreas samples were taken. Tissue zinc concentration and metallothionein abundance was greater with HZn compared with NZn and LZn (Ppancreas tissue was higher with HZn diets compared with the other treatments (Ppancreas of young pigs. The data provide new insights into pancreatic function under outbalanced zinc homeostasis.

  14. Identification of the human zinc transcriptional regulatory element (ZTRE): a palindromic protein-binding DNA sequence responsible for zinc-induced transcriptional repression

    NARCIS (Netherlands)

    Coneyworth, L.J.; Jackson, K.A.; Tyson, J.; Bosomworth, H.J.; Hagen, E.A.E. van der; Hann, G.M.; Ogo, O.A.; Swann, D.C.; Mathers, J.C.; Valentine, R.A.; Ford, D.

    2012-01-01

    Many genes with crucial roles in zinc homeostasis in mammals respond to fluctuating zinc supply through unknown mechanisms, and uncovering these mechanisms is essential to understanding the process at cellular and systemic levels. We detected zinc-dependent binding of a zinc-induced protein to a spe

  15. Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly:A randomized double-blind placebo-controlled trial

    Science.gov (United States)

    Background: Zinc is essential for the regulation of immune response. T cell function declines with age. Zinc supplementation has the potential to improve serum zinc concentrations and immunity of nursing home elderly with low serum zinc concentration. Objective: We aimed to determine the effect of ...

  16. Modular, Hierarchical Learning By Artificial Neural Networks

    Science.gov (United States)

    Baldi, Pierre F.; Toomarian, Nikzad

    1996-01-01

    Modular and hierarchical approach to supervised learning by artificial neural networks leads to neural networks more structured than neural networks in which all neurons fully interconnected. These networks utilize general feedforward flow of information and sparse recurrent connections to achieve dynamical effects. The modular organization, sparsity of modular units and connections, and fact that learning is much more circumscribed are all attractive features for designing neural-network hardware. Learning streamlined by imitating some aspects of biological neural networks.

  17. A Study on Associative Neural Memories

    OpenAIRE

    B.D.C.N.Prasad; P. E. S. N. Krishna Prasad; Sagar Yeruva; P Sita Rama Murty

    2011-01-01

    Memory plays a major role in Artificial Neural Networks. Without memory, Neural Network can not be learned itself. One of the primary concepts of memory in neural networks is Associative neural memories. A survey has been made on associative neural memories such as Simple associative memories (SAM), Dynamic associative memories (DAM), Bidirectional Associative memories (BAM), Hopfield memories, Context Sensitive Auto-associative memories (CSAM) and so on. These memories can be applied in vari...

  18. Artificial intelligence: Deep neural reasoning

    Science.gov (United States)

    Jaeger, Herbert

    2016-10-01

    The human brain can solve highly abstract reasoning problems using a neural network that is entirely physical. The underlying mechanisms are only partially understood, but an artificial network provides valuable insight. See Article p.471

  19. Logic Mining Using Neural Networks

    CERN Document Server

    Sathasivam, Saratha

    2008-01-01

    Knowledge could be gained from experts, specialists in the area of interest, or it can be gained by induction from sets of data. Automatic induction of knowledge from data sets, usually stored in large databases, is called data mining. Data mining methods are important in the management of complex systems. There are many technologies available to data mining practitioners, including Artificial Neural Networks, Regression, and Decision Trees. Neural networks have been successfully applied in wide range of supervised and unsupervised learning applications. Neural network methods are not commonly used for data mining tasks, because they often produce incomprehensible models, and require long training times. One way in which the collective properties of a neural network may be used to implement a computational task is by way of the concept of energy minimization. The Hopfield network is well-known example of such an approach. The Hopfield network is useful as content addressable memory or an analog computer for s...

  20. Neural communication in posttraumatic growth.

    Science.gov (United States)

    Anders, Samantha L; Peterson, Carly K; James, Lisa M; Engdahl, Brian; Leuthold, Arthur C; Georgopoulos, Apostolos P

    2015-07-01

    Posttraumatic growth (PTG), or positive psychological changes following exposure to traumatic events, is commonly reported among trauma survivors. In the present study, we examined neural correlates of PTG in 106 veterans with PTSD and 193 veteran controls using task-free magnetoencephalography (MEG), diagnostic interviews and measures of PTG, and traumatic event exposure. Global synchronous neural interactions (SNIs) were significantly modulated downward with increasing PTG scores in controls (p = .005), but not in veterans with PTSD (p = .601). This effect was primarily characterized by negative slopes in local neural networks, was strongest in the medial prefrontal cortex, and was much stronger and more extensive in the control than the PTSD group. The present study complements previous research highlighting the role of neural adaptation in healthy functioning.

  1. Neural Networks in Control Applications

    DEFF Research Database (Denmark)

    Sørensen, O.

    examined, and it appears that considering 'normal' neural network models with, say, 500 samples, the problem of over-fitting is neglible, and therefore it is not taken into consideration afterwards. Numerous model types, often met in control applications, are implemented as neural network models....... - Control concepts including parameter estimation - Control concepts including inverse modelling - Control concepts including optimal control For each of the three groups, different control concepts and specific training methods are detailed described.Further, all control concepts are tested on the same......The intention of this report is to make a systematic examination of the possibilities of applying neural networks in those technical areas, which are familiar to a control engineer. In other words, the potential of neural networks in control applications is given higher priority than a detailed...

  2. Complex-Valued Neural Networks

    CERN Document Server

    Hirose, Akira

    2012-01-01

    This book is the second enlarged and revised edition of the first successful monograph on complex-valued neural networks (CVNNs) published in 2006, which lends itself to graduate and undergraduate courses in electrical engineering, informatics, control engineering, mechanics, robotics, bioengineering, and other relevant fields. In the second edition the recent trends in CVNNs research are included, resulting in e.g. almost a doubled number of references. The parametron invented in 1954 is also referred to with discussion on analogy and disparity. Also various additional arguments on the advantages of the complex-valued neural networks enhancing the difference to real-valued neural networks are given in various sections. The book is useful for those beginning their studies, for instance, in adaptive signal processing for highly functional sensing and imaging, control in unknown and changing environment, robotics inspired by human neural systems, and brain-like information processing, as well as interdisciplina...

  3. Neural correlates of consciousness reconsidered.

    Science.gov (United States)

    Neisser, Joseph

    2012-06-01

    It is widely accepted among philosophers that neuroscientists are conducting a search for the neural correlates of consciousness, or NCC. Chalmers (2000) conceptualized this research program as the attempt to correlate the contents of conscious experience with the contents of representations in specific neural populations. A notable claim on behalf of this interpretation is that the neutral language of "correlates" frees us from philosophical disputes over the mind/body relation, allowing the science to move independently. But the experimental paradigms and explanatory canons of neuroscience are not neutral about the mechanical relation between consciousness and the brain. I argue that NCC research is best characterized as an attempt to locate a causally relevant neural mechanism and not as an effort to identify a discrete neural representation, the content of which correlates with some actual experience. It might be said that the first C in "NCC" should stand for "causes" rather than "correlates."

  4. Neural components of altruistic punishment

    Directory of Open Access Journals (Sweden)

    Emily eDu

    2015-02-01

    Full Text Available Altruistic punishment, which occurs when an individual incurs a cost to punish in response to unfairness or a norm violation, may play a role in perpetuating cooperation. The neural correlates underlying costly punishment have only recently begun to be explored. Here we review the current state of research on the neural basis of altruism from the perspectives of costly punishment, emphasizing the importance of characterizing elementary neural processes underlying a decision to punish. In particular, we emphasize three cognitive processes that contribute to the decision to altruistically punish in most scenarios: inequity aversion, cost-benefit calculation, and social reference frame to distinguish self from others. Overall, we argue for the importance of understanding the neural correlates of altruistic punishment with respect to the core computations necessary to achieve a decision to punish.

  5. Effect of short-term zinc supplementation on zinc and selenium tissue distribution and serum antioxidant enzymes

    Directory of Open Access Journals (Sweden)

    Andrey A. Skalny

    2015-09-01

    Full Text Available Background. A significant association between Zn and Se homeostasis exists. At the same time, data on the influence of zinc supplementation on selenium distribution in organs and tissues seem to be absent. Therefore, the primary objective of the current study is to investigate the infl uence of zinc asparaginate supplementation on zinc and selenium distribution and serum superoxide dismutase (SOD and glutathione peroxidase (GPx activity in Wistar rats. Material and methods. 36 rats were used in the experiment. The duration of the experiment was 7 and 14 days in the fi rst and second series, respectively. The rats in Group I were used as the control ones. Animals in Groups II and III daily obtained zinc asparaginate (ZnA in the doses of 5 and 15 mg/kg weight, respectively. Zinc and selenium content in liver, kidneys, heart, muscle, serum and hair was assessed using inductively coupled plasma mass spectrometry. Serum SOD and GPx activity was analysed spectrophotometrically using Randox kits. Results. Intragastric administration of zinc asparaginate signifi cantly increased liver, kidney, and serum zinc content without affecting skeletal and cardiac muscle levels. Zinc supplementation also stimulated selenium retention in the rats’ organs. Moreover, a significant positive correlation between zinc and selenium content was observed. Finally, zinc asparaginate treatment has been shown to modulate serum GPx but not SOD activity. Conclusion. The obtained data indicate that zinc-induced increase in GPx activity may be mediated through modulation of selenium status. However, future studies are required to estimate the exact mechanisms of zinc and selenium interplay.

  6. Zinc bioavailability in rats fed a plant-based diet: a study of fermentation and zinc supplementation

    Directory of Open Access Journals (Sweden)

    Claudia E. Lazarte

    2015-11-01

    Full Text Available Background: Zinc deficiency is a significant problem, in developing countries and in vegetarians, which can be caused by plant-based diets. Thus, dietary strategies, such as fermentation, to improve zinc bioavailability of diets should be investigated. Objective: To improve zinc bioavailability in a plant-based diet by the inclusion of fermented food. Design: Cassava tubers were fermented and made to replace the unfermented cassava in a basal plant-based diet, and compared with plant-based diets with and without zinc supplement. The zinc bioavailability of the diets was evaluated in Wistar rats that were fed these diets for 28 days. The evaluation was for zinc apparent absorption (ZnAA, serum zinc levels, and zinc deposits in liver and femur; in addition, the feed efficiency ratio (FER of the diets and femur weight (FW of the rats were evaluated. Results: During the cassava fermentation, lactic acid increased and pH decreased (from 6.8 to 3.9, which is favorable for native phytase activity, resulting in a 90.2% reduction of phytate content in cassava. The diet containing fermented cassava showed significantly higher levels of ZnAA, FER, and FW (p<0.001. Moreover, the zinc levels in serum and femur were significantly higher (p<0.001 compared with the results of the diet with unfermented cassava. The results clearly show a higher zinc bioavailability in the diet containing fermented cassava and are comparable with the results obtained with the plant-based diet with zinc supplement. Conclusions: In conclusion, the fermentation of cassava reduces the phytate content. The diet containing the fermented cassava represents a better nutritional alternative than the diet with unfermented cassava and is comparable with the zinc-supplemented diets.

  7. Ultrafine Zinc and Nickel, Palladium, Silver Coated Zinc Particles Used for Reductive Dehalogenation of Chlorinated Ethylenes in Aqueous Solution

    OpenAIRE

    Li, Weifeng; Kenneth J. Klabunde

    1998-01-01

    Zero-valent zinc metal has been employed for the reductive dehalogenation of chlorinated ethylenes. In order to enhance this environmental remediation chemistry, ultrafine zinc particles and transition metal additives (coatings) have been employed. Indeed, activated zinc (cryozinc) significantly enhanced the reduction/dehalogenation process, especially in the presence of nickel and palladium coatings. These reagents were able to achieve rapid, deep reductive dehalogenation of trichloroethylen...

  8. Serotonin, neural markers, and memory

    OpenAIRE

    Alfredo eMeneses

    2015-01-01

    Diverse neuropsychiatric disorders present dysfunctional memory and no effective treatment exits for them; likely as result of the absence of neural markers associated to memory. Neurotransmitter systems and signaling pathways have been implicated in memory and dysfunctional memory; however, their role is poorly understood. Hence, neural markers and cerebral functions and dysfunctions are revised. To our knowledge no previous systematic works have been published addressing these issues. The i...

  9. What are artificial neural networks?

    DEFF Research Database (Denmark)

    Krogh, Anders

    2008-01-01

    Artificial neural networks have been applied to problems ranging from speech recognition to prediction of protein secondary structure, classification of cancers and gene prediction. How do they work and what might they be good for? Udgivelsesdato: 2008-Feb......Artificial neural networks have been applied to problems ranging from speech recognition to prediction of protein secondary structure, classification of cancers and gene prediction. How do they work and what might they be good for? Udgivelsesdato: 2008-Feb...

  10. Neural Network Communications Signal Processing

    Science.gov (United States)

    1994-08-01

    Technical Information Report for the Neural Network Communications Signal Processing Program, CDRL A003, 31 March 1993. Software Development Plan for...track changing jamming conditions to provide the decoder with the best log- likelihood ratio metrics at a given time. As part of our development plan we...Artificial Neural Networks (ICANN-91) Volume 2, June 24-28, 1991, pp. 1677-1680. Kohonen, Teuvo, Raivio, Kimmo, Simula, Oli, Venta , 011i, Henriksson

  11. X-ray absorption fine structure analysis of the local environment of zinc in dentine treated with zinc compounds.

    Science.gov (United States)

    Takatsuka, Tsutomu; Hirano, Junko; Matsumoto, Hitoshi; Honma, Tetsuo

    2005-04-01

    It has been reported that zinc oxide (ZnO) inhibits dentine demineralization. By using the X-ray absorption fine structure (XAFS) technique, our aims in this study were to provide information about the local environment of zinc atoms in dentine that had been treated with zinc compounds. We measured the Zn K-edge X-ray absorption near-edge structure (XANES) and the extended X-ray absorption fine structure (EXAFS) of dentine specimens treated with zinc chloride or ZnO. In XAFS analyses, the spectra of dentine specimens treated with ZnO (D-ZO) or with zinc chloride (D-ZC) were similar and obviously different from the reference ZnO spectrum. This suggests that most of the zinc atoms detected in D-ZO are not derived from particles of ZnO. The spectra of D-ZO and D-ZC were similar to the spectrum of the synthetic, zinc-containing hydroxyapatite, but were not similar to that of zinc in ZnCl2-treated collagen. The results of this study suggest that most of the zinc atoms detected were attached to hydroxyapatite and not to collagen.

  12. Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks

    Energy Technology Data Exchange (ETDEWEB)

    Que, Emily L.; Bleher, Reiner; Duncan, Francesca E.; Kong, Betty Y.; Gleber, Sophie C.; Vogt, Stefan; Chen, Si; Garwin, Seth A.; Bayer, Amanda R.; Dravid, Vinayak P.; Woodruff, Teresa K.; O' Halloran, Thomas V.

    2014-12-15

    Fertilization of a mammalian egg initiates a series of 'zinc sparks' that are necessary to induce the egg-to-embryo transition. Despite the importance of these zinc-efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches that resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy-dispersive spectroscopy, X-ray fluorescence microscopy and three-dimensional elemental tomography for high-resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each of which contains, on average, 10(6) zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes

  13. Etapas iniciales del zinc runoff en clima tropical Etapas iniciales del zinc runoff en clima tropical

    Directory of Open Access Journals (Sweden)

    Meraz, E.

    2007-04-01

    Full Text Available Frecuently used metals in building application are Zinc and hot dip galvanized steel. The zinc has a relativelly good atmospheric resitance, due to its oxidation in air and formation of protective layer. However, some of the zinc corrosion products can be dissolved by pluvial precipitations and water condensed on the metal surface. This process is called metal runof. In order to estimate el zinc runoff in humid tropical climate, since its firs stages, samples of pure zinc and hot dip galvanized steel have been exposed during 2 years in outdorr atmosphere (rural and urban. The data reveal high annual values of zinc runoff (8,20–12,40 ±0.30 g/m2año, being this process 80% of total mass loss of corroded zinc. The runoff and corrosion processes are more accelerated for zinc, than that of galvanized steel. The principal factors that control the runoff process are discussed.

    El zinc y acero galvanizado (hot dip se utilizan frecuentemente como materiales de construcción. El zinc tiene relativamente buena resistencia en la atmósfera debido a su oxidación en el aire, formando una capa protectora. Sin embargo, algunos productos de corrosión de zinc pueden ser disueltos por las lluvias y agua condensada sobre la superficie del metal. Este proceso es conocido como runoff del metal. Con el objetivo de estimar el proceso de runoff de zinc desde sus primeras etapas en clima tropical húmedo, muestras de zinc puro y acero galvanizado han sido expuestas en atmósfera abierta (rural y urbana durante 2 años. Los resultados revelan altos valores de runoff de zinc (8,20–12,40 ±0,30 g/m2año, siendo este, hasta 80 % de la masa total perdida por corrosión del zinc. El proceso runoff y de corrosión es más acelerado en el zinc, que en el acero galvanizado. Se discuten los principales factores que controlan el proceso runoff.

  14. Flexibility of neural stem cells

    Directory of Open Access Journals (Sweden)

    Eumorphia eRemboutsika

    2011-04-01

    Full Text Available Embryonic cortical neural stem cells are self-renewing progenitors that can differentiate into neurons and glia. We generated neurospheres from the developing cerebral cortex using a mouse genetic model that allows for lineage selection and found that the self-renewing neural stem cells are restricted to Sox2 expressing cells. Under normal conditions, embryonic cortical neurospheres are heterogeneous with regard to Sox2 expression and contain astrocytes, neural stem cells and neural progenitor cells sufficiently plastic to give rise to neural crest cells when transplanted into the hindbrain of E1.5 chick and E8 mouse embryos. However, when neurospheres are maintained under lineage selection, such that all cells express Sox2, neural stem cells maintain their Pax6+ cortical radial glia identity and exhibit a more restricted fate in vitro and after transplantation. These data demonstrate that Sox2 preserves the cortical identity and regulates the plasticity of self-renewing Pax6+ radial glia cells.

  15. Potential ecological risk assessment and predicting zinc accumulation in soils.

    Science.gov (United States)

    Baran, Agnieszka; Wieczorek, Jerzy; Mazurek, Ryszard; Urbański, Krzysztof; Klimkowicz-Pawlas, Agnieszka

    2017-02-22

    The aims of this study were to investigate zinc content in the studied soils; evaluate the efficiency of geostatistics in presenting spatial variability of zinc in the soils; assess bioavailable forms of zinc in the soils and to assess soil-zinc binding ability; and to estimate the potential ecological risk of zinc in soils. The study was conducted in southern Poland, in the Malopolska Province. This area is characterized by a great diversity of geological structures and types of land use and intensity of industrial development. The zinc content was affected by soil factors, and the type of land use (arable lands, grasslands, forests, wastelands). A total of 320 soil samples were characterized in terms of physicochemical properties (texture, pH, organic C content, total and available Zn content). Based on the obtained data, assessment of the ecological risk of zinc was conducted using two methods: potential ecological risk index and hazard quotient. Total Zn content in the soils ranged from 8.27 to 7221 mg kg(-1) d.m. Based on the surface semivariograms, the highest variability of zinc in the soils was observed from northwest to southeast. The point sources of Zn contamination were located in the northwestern part of the area, near the mining-metallurgical activity involving processing of zinc and lead ores. These findings were confirmed by the arrangement of semivariogram surfaces and bivariate Moran's correlation coefficients. The content of bioavailable forms of zinc was between 0.05 and 46.19 mg kg(-1) d.m. (0.01 mol dm(-3) CaCl2), and between 0.03 and 71.54 mg kg(-1) d.m. (1 mol dm(-3) NH4NO3). Forest soils had the highest zinc solubility, followed by arable land, grassland and wasteland. PCA showed that organic C was the key factor to control bioavailability of zinc in the soils. The extreme, very high and medium zinc accumulation was found in 69% of studied soils. There is no ecological risk of zinc to living organisms in the study area, and in 90

  16. Zinc deficiency is common in several psychiatric disorders.

    Directory of Open Access Journals (Sweden)

    Ole Grønli

    Full Text Available BACKGROUND: Mounting evidence suggests a link between low zinc levels and depression. There is, however, little knowledge about zinc levels in older persons with other psychiatric diagnoses. Therefore, we explore the zinc status of elderly patients suffering from a wide range of psychiatric disorders. METHODS: Clinical data and blood samples for zinc analyzes were collected from 100 psychogeriatric patients over 64 of age. Psychiatric and cognitive symptoms were assessed using the Montgomery and Aasberg Depression Rating Scale, the Cornell Scale for Depression in Dementia, the Mini-Mental State Examination, the Clockdrawing Test, clinical interviews and a review of medical records. In addition, a diagnostic interview was conducted using the Mini International Neuropsychiatric Interview instrument. The prevalence of zinc deficiency in patients with depression was compared with the prevalence in patients without depression, and the prevalence in a control group of 882 older persons sampled from a population study. RESULTS: There was a significant difference in zinc deficiency prevalence between the control group (14.4% and the patient group (41.0% (χ(2 = 44.81, df = 1, p<0.001. In a logistic model with relevant predictors, zinc deficiency was positively associated with gender and with serum albumin level. The prevalence of zinc deficiency in the patient group was significantly higher in patients without depression (i.e. with other diagnoses than in patients with depression as a main diagnosis or comorbid depression (χ(2 = 4.36, df = 1, p = 0.037. CONCLUSIONS: Zinc deficiency is quite common among psychogeriatric patients and appears to be even more prominent in patients suffering from other psychiatric disorders than depression. LIMITATIONS: This study does not provide a clear answer as to whether the observed differences represent a causal relationship between zinc deficiency and psychiatric symptoms. The blood sample collection time points

  17. Zinc in Pancreatic Islet Biology, Insulin Sensitivity, and Diabetes

    Science.gov (United States)

    Maret, Wolfgang

    2017-01-01

    About 20 chemical elements are nutritionally essential for humans with defined molecular functions. Several essential and nonessential biometals are either functional nutrients with antidiabetic actions or can be diabetogenic. A key question remains whether changes in the metabolism of biometals and biominerals are a consequence of diabetes or are involved in its etiology. Exploration of the roles of zinc (Zn) in this regard is most revealing because 80 years of scientific discoveries link zinc and diabetes. In pancreatic β- and α-cells, zinc has specific functions in the biochemistry of insulin and glucagon. When zinc ions are secreted during vesicular exocytosis, they have autocrine, paracrine, and endocrine roles. The membrane protein ZnT8 transports zinc ions into the insulin and glucagon granules. ZnT8 has a risk allele that predisposes the majority of humans to developing diabetes. In target tissues, increased availability of zinc enhances the insulin response by inhibiting protein tyrosine phosphatase 1B, which controls the phosphorylation state of the insulin receptor and hence downstream signalling. Inherited diseases of zinc metabolism, environmental exposures that interfere with the control of cellular zinc homeostasis, and nutritional or conditioned zinc deficiency influence the patho-biochemistry of diabetes. Accepting the view that zinc is one of the many factors in multiple gene-environment interactions that cause the functional demise of β-cells generates an immense potential for treating and perhaps preventing diabetes. Personalized nutrition, bioactive food, and pharmaceuticals targeting the control of cellular zinc in precision medicine are among the possible interventions.

  18. Recurrent neural collective classification.

    Science.gov (United States)

    Monner, Derek D; Reggia, James A

    2013-12-01

    With the recent surge in availability of data sets containing not only individual attributes but also relationships, classification techniques that take advantage of predictive relationship information have gained in popularity. The most popular existing collective classification techniques have a number of limitations-some of them generate arbitrary and potentially lossy summaries of the relationship data, whereas others ignore directionality and strength of relationships. Popular existing techniques make use of only direct neighbor relationships when classifying a given entity, ignoring potentially useful information contained in expanded neighborhoods of radius greater than one. We present a new technique that we call recurrent neural collective classification (RNCC), which avoids arbitrary summarization, uses information about relationship directionality and strength, and through recursive encoding, learns to leverage larger relational neighborhoods around each entity. Experiments with synthetic data sets show that RNCC can make effective use of relationship data for both direct and expanded neighborhoods. Further experiments demonstrate that our technique outperforms previously published results of several collective classification methods on a number of real-world data sets.

  19. Arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xi; Zhou, Xixi [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Du, Libo [Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Liu, Wenlan [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Liu, Yang [Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Hudson, Laurie G. [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States); Liu, Ke Jian, E-mail: kliu@salud.unm.edu [Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico Health Sciences Center, Albuquerque, NM 87131 (United States)

    2014-01-15

    Inhibition of DNA repair is a recognized mechanism for arsenic enhancement of ultraviolet radiation-induced DNA damage and carcinogenesis. Poly(ADP-ribose) polymerase-1 (PARP-1), a zinc finger DNA repair protein, has been identified as a sensitive molecular target for arsenic. The zinc finger domains of PARP-1 protein function as a critical structure in DNA recognition and binding. Since cellular poly(ADP-ribosyl)ation capacity has been positively correlated with zinc status in cells, we hypothesize that arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair. To test this hypothesis, we compared the effects of arsenite exposure with zinc deficiency, created by using the membrane-permeable zinc chelator TPEN, on 8-OHdG formation, PARP-1 activity and zinc binding to PARP-1 in HaCat cells. Our results show that arsenite exposure and zinc deficiency had similar effects on PARP-1 protein, whereas supplemental zinc reversed these effects. To investigate the molecular mechanism of zinc loss induced by arsenite, ICP-AES, near UV spectroscopy, fluorescence, and circular dichroism spectroscopy were utilized to examine arsenite binding and occupation of a peptide representing the first zinc finger of PARP-1. We found that arsenite binding as well as zinc loss altered the conformation of zinc finger structure which functionally leads to PARP-1 inhibition. These findings suggest that arsenite binding to PARP-1 protein created similar adverse biological effects as zinc deficiency, which establishes the molecular mechanism for zinc supplementation as a potentially effective treatment to reverse the detrimental outcomes of arsenic exposure. - Highlights: • Arsenite binding is equivalent to zinc deficiency in reducing PARP-1 function. • Zinc reverses arsenic inhibition of PARP-1 activity and enhancement of DNA damage. • Arsenite binding and zinc loss alter the conformation of zinc finger

  20. ANTIFUNGAL EFFECT OF ZINC OXIDE BASED PASTES CONTAINING VARIOUS ESSENTIAL OILS AGAINST CANDIDA ALBICANS AND COMPARISON OF ITS EFFECT WITH ZINC OXIDE EUGENOL

    OpenAIRE

    Dr.Nilima Thosar*, Dr. Manoj Chandak, Dr.Manohar Bhat, Dr.Silpi Basak

    2016-01-01

    Background: Endodontic treatment of primary teeth is required to eliminate microorganisms from the infected root canals having complex root canal anatomy. Objectives: To assess the antifungal effect of zinc oxide paste with tea tree oil, thyme oil, peppermint oil on candida albicans and to compare it with zinc oxide eugenol paste. Materials and methods: Zinc oxide pastes containing essential oils used in the present study were zinc oxide tea tree oil paste (ZOT); zinc oxide thyme oil ...

  1. Enterococcus faecalis zinc-responsive proteins mediate bacterial defence against zinc overload, lysozyme and oxidative stress

    NARCIS (Netherlands)

    C. Abrantes, Marta; Kok, Jan; de Fatima Silva Lopes, Maria

    2014-01-01

    Two Enterococcus faecalis genes encoding the P-type ATPase EF1400 and the putative SapB protein EF0759 were previously shown to be strongly upregulated in the presence of high concentrations of zinc. In the present work, we showed that a Zn(2+)-responsive DNA-binding motif (zim) is present in the pr

  2. Enterococcus faecalis zinc-responsive proteins mediate bacterial defence against zinc overload, lysozyme and oxidative stress.

    Science.gov (United States)

    Abrantes, Marta C; Kok, Jan; Silva Lopes, Maria de Fátima

    2014-12-01

    Two Enterococcus faecalis genes encoding the P-type ATPase EF1400 and the putative SapB protein EF0759 were previously shown to be strongly upregulated in the presence of high concentrations of zinc. In the present work, we showed that a Zn(2+)-responsive DNA-binding motif (zim) is present in the promoter regions of these genes. Both proteins were further studied with respect to their involvement in zinc homeostasis and invasion of the host. EF0759 contributed to intramacrophage survival by an as-yet unknown mechanism(s). EF1400, here renamed ZntAEf, is an ATPase with specificity for zinc and plays a role in dealing with several host defences, i.e. zinc overload, oxidative stress and lysozyme; it provides E. faecalis cells with the ability to survive inside macrophages. As these three host defence mechanisms are important at several sites in the host, i.e. inside macrophages and in saliva, this work suggested that ZntAEf constitutes a crucial E. faecalis defence mechanism that is likely to contribute to the ability of this bacterium to endure life inside its host.

  3. Zinc Biofortification of Rice in China: A stimulation of zinc intake with different dietary patterns

    NARCIS (Netherlands)

    Qin, Y.; Boonstra, A.; Yuan, B.; Pan, X.; Dai, Yue

    2012-01-01

    A cross-sectional survey of 2819 adults aged 20 years and above was undertaken in 2002 in Jiangsu Province. Zinc intake was assessed using a consecutive 3-day 24-h dietary recall method. Insufficient and excess intake was determined according to the Chinese Dietary Recommended Intakes. Four distinct

  4. Administration of Zinc plus Cyclo-(His-Pro Increases Hippocampal Neurogenesis in Rats during the Early Phase of Streptozotocin-Induced Diabetes

    Directory of Open Access Journals (Sweden)

    Bo Young Choi

    2017-01-01

    Full Text Available The effects of zinc supplementation on hippocampal neurogenesis in diabetes mellitus have not been studied. Herein, we investigated the effects of zinc plus cyclo-(His-Pro (ZC on neurogenesis occurring in the subgranular zone of dentate gyrus after streptozotocin (STZ-induced diabetes. ZC (27 mg/kg was administered by gavage once daily for one or six weeks from the third day after the STZ injection, and histological evaluation was performed at 10 (early phase or 45 (late phase days after STZ injection. We found that the proliferation of progenitor cells in STZ-induced diabetic rats showed an increase in the early phase. Additionally, ZC treatment remarkably increased the number of neural progenitor cells (NPCs and immature neurons in the early phase of STZ-induced diabetic rats. Furthermore, ZC treatment showed increased survival rate of newly generated cells but no difference in the level of neurogenesis in the late phase of STZ-induced diabetic rats. The present study demonstrates that zinc supplementation by ZC increases both NPCs proliferation and neuroblast production at the early phase of diabetes. Thus, this study suggests that zinc supplemented with a histidine/proline complex may have beneficial effects on neurogenesis in patients experiencing the early phase of Type 1 diabetes.

  5. Administration of Zinc plus Cyclo-(His-Pro) Increases Hippocampal Neurogenesis in Rats during the Early Phase of Streptozotocin-Induced Diabetes

    Science.gov (United States)

    Choi, Bo Young; Kim, In Yeol; Kim, Jin Hee; Lee, Bo Eun; Lee, Song Hee; Kho, A Ra; Sohn, Min; Suh, Sang Won

    2017-01-01

    The effects of zinc supplementation on hippocampal neurogenesis in diabetes mellitus have not been studied. Herein, we investigated the effects of zinc plus cyclo-(His-Pro) (ZC) on neurogenesis occurring in the subgranular zone of dentate gyrus after streptozotocin (STZ)-induced diabetes. ZC (27 mg/kg) was administered by gavage once daily for one or six weeks from the third day after the STZ injection, and histological evaluation was performed at 10 (early phase) or 45 (late phase) days after STZ injection. We found that the proliferation of progenitor cells in STZ-induced diabetic rats showed an increase in the early phase. Additionally, ZC treatment remarkably increased the number of neural progenitor cells (NPCs) and immature neurons in the early phase of STZ-induced diabetic rats. Furthermore, ZC treatment showed increased survival rate of newly generated cells but no difference in the level of neurogenesis in the late phase of STZ-induced diabetic rats. The present study demonstrates that zinc supplementation by ZC increases both NPCs proliferation and neuroblast production at the early phase of diabetes. Thus, this study suggests that zinc supplemented with a histidine/proline complex may have beneficial effects on neurogenesis in patients experiencing the early phase of Type 1 diabetes. PMID:28045430

  6. 15-zinc finger protein Bloody Fingers is required for zebrafish morphogenetic movements during neurulation.

    Science.gov (United States)

    Sumanas, Saulius; Zhang, Bo; Dai, Rujuan; Lin, Shuo

    2005-07-01

    A novel zebrafish gene bloody fingers (blf) encoding a 478 amino acid protein containing fifteen C(2)H(2) type zinc fingers was identified by expression screening. As determined by in situ hybridization, blf RNA displays strong ubiquitous early zygotic expression, while during late gastrulation and early somitogenesis, blf expression becomes transiently restricted to the posterior dorsal and lateral mesoderm. During later somitogenesis, blf expression appears only in hematopoietic cells. It is completely eliminated in cloche, moonshine but not in vlad tepes (gata1) mutant embryos. Morpholino (MO) knockdown of the Blf protein results in the defects of morphogenetic movements. Blf-MO-injected embryos (morphants) display shortened and widened axial tissues due to defective convergent extension. Unlike other convergent extension mutants, blf morphants display a split neural tube, resulting in a phenotype similar to the human open neural tube defect spina bifida. In addition, dorsal ectodermal cells delaminate in blf morphants during late somitogenesis. We propose a model explaining the role of blf in convergent extension and neurulation. We conclude that blf plays an important role in regulating morphogenetic movements during gastrulation and neurulation while its role in hematopoiesis may be redundant.

  7. Magnetic resonance in superparamagnetic zinc ferrite

    Indian Academy of Sciences (India)

    Jitendra Pal Singh; Gagan Dixit; R C Srivastava; Hemant Kumar; H M Agrawal; Prem Chand

    2013-08-01

    In the present work, we have synthesized zinc ferrite nanoparticles by nitrate method. Presence of almost zero value of coercivity and remanence in the hysteresis of these samples shows the superparamagnetic nature at room temperature. Electron paramagnetic resonance spectroscopy performed on these samples in the temperature range 120–300 K indicates the systematic variation of the line-shapes of the spectra with temperature. Both gvalue and peak-to-peak linewidth decrease with increase in temperature. The variation of g-values and peak-topeak linewidth with temperature has been fitted with existing models and we observed different values of activation energies of the spins for both the samples.

  8. Chirality sensing with stereodynamic biphenolate zinc complexes.

    Science.gov (United States)

    Bentley, Keith W; de Los Santos, Zeus A; Weiss, Mary J; Wolf, Christian

    2015-10-01

    Two bidentate ligands consisting of a fluxional polyarylacetylene framework with terminal phenol groups were synthesized. Reaction with diethylzinc gives stereodynamic complexes that undergo distinct asymmetric transformation of the first kind upon binding of chiral amines and amino alcohols. The substrate-to-ligand chirality imprinting at the zinc coordination sphere results in characteristic circular dichroism signals that can be used for direct enantiomeric excess (ee) analysis. This chemosensing approach bears potential for high-throughput ee screening with small sample amounts and reduced solvent waste compared to traditional high-performance liquid chromatography methods.

  9. Severe Zinc Depletion of Escherichia coli: ROLES FOR HIGH AFFINITY ZINC BINDING BY ZinT, ZINC TRANSPORT AND ZINC-INDEPENDENT PROTEINS*

    OpenAIRE

    Graham, A.I.; Hunt, S; Stokes, S.L.; Bramall, N.; Bunch, J.; Cox, A G; McLeod, C.W.; Poole, R K

    2009-01-01

    Zinc ions play indispensable roles in biological chemistry. However, bacteria have an impressive ability to acquire Zn2+ from the environment, making it exceptionally difficult to achieve Zn2+ deficiency, and so a comprehensive understanding of the importance of Zn2+ has not been attained. Reduction of the Zn2+ content of Escherichia coli growth medium to 60 nM or less is reported here for the first time, without recourse to chelators of poor specificity. Cells grown in Zn2+-deficient medium ...

  10. Mechanical characterization of microwave sintered zinc oxide

    Indian Academy of Sciences (India)

    A K Mukhopadhyay; M Ray Chaudhuri; A Seal; S K Dalui; M Banerjee; K K Phani

    2001-04-01

    The mechanical characterization of microwave sintered zinc oxide disks is reported. The microwave sintering was done with a specially designed applicator placed in a domestic microwave oven operating at a frequency of 2.45 GHz to a maximum power output of 800 Watt. These samples with a wide variation of density and hence, of open pore volume percentage, were characterized in terms of its elastic modulus determination by ultrasonic time of flight measurement using a 15 MHz transducer. In addition, the load dependence of the microhardness was examined for the range of loads 0.1–20 N. Finally, the fracture toughness data (IC) was obtained using the indentation technique.

  11. Antimicrobial property of zinc based nanoparticles

    Science.gov (United States)

    Chiriac, V.; Stratulat, D. N.; Calin, G.; Nichitus, S.; Burlui, V.; Stadoleanu, C.; Popa, M.; Popa, I. M.

    2016-06-01

    Pathogen bacteria strains with wide spectrum can cause serious infections with drastic damages on humans. There are studies reflecting antibacterial effect of nanoparticles type metal or metal oxides as an alternative or concurrent treatment to the diseases caused by infectious agents. Synthesised nanoparticles using different methods like sol-gel, hydrothermal or plant extraction were tested following well-established protocols with the regard to their antimicrobial activity. It was found that zinc based nanoparticles possess strong synergistic effect with commonly used antibiotics on infection tratment.

  12. Fractional Hopfield Neural Networks: Fractional Dynamic Associative Recurrent Neural Networks.

    Science.gov (United States)

    Pu, Yi-Fei; Yi, Zhang; Zhou, Ji-Liu

    2016-07-14

    This paper mainly discusses a novel conceptual framework: fractional Hopfield neural networks (FHNN). As is commonly known, fractional calculus has been incorporated into artificial neural networks, mainly because of its long-term memory and nonlocality. Some researchers have made interesting attempts at fractional neural networks and gained competitive advantages over integer-order neural networks. Therefore, it is naturally makes one ponder how to generalize the first-order Hopfield neural networks to the fractional-order ones, and how to implement FHNN by means of fractional calculus. We propose to introduce a novel mathematical method: fractional calculus to implement FHNN. First, we implement fractor in the form of an analog circuit. Second, we implement FHNN by utilizing fractor and the fractional steepest descent approach, construct its Lyapunov function, and further analyze its attractors. Third, we perform experiments to analyze the stability and convergence of FHNN, and further discuss its applications to the defense against chip cloning attacks for anticounterfeiting. The main contribution of our work is to propose FHNN in the form of an analog circuit by utilizing a fractor and the fractional steepest descent approach, construct its Lyapunov function, prove its Lyapunov stability, analyze its attractors, and apply FHNN to the defense against chip cloning attacks for anticounterfeiting. A significant advantage of FHNN is that its attractors essentially relate to the neuron's fractional order. FHNN possesses the fractional-order-stability and fractional-order-sensitivity characteristics.

  13. The holographic neural network: Performance comparison with other neural networks

    Science.gov (United States)

    Klepko, Robert

    1991-10-01

    The artificial neural network shows promise for use in recognition of high resolution radar images of ships. The holographic neural network (HNN) promises a very large data storage capacity and excellent generalization capability, both of which can be achieved with only a few learning trials, unlike most neural networks which require on the order of thousands of learning trials. The HNN is specially designed for pattern association storage, and mathematically realizes the storage and retrieval mechanisms of holograms. The pattern recognition capability of the HNN was studied, and its performance was compared with five other commonly used neural networks: the Adaline, Hamming, bidirectional associative memory, recirculation, and back propagation networks. The patterns used for testing represented artificial high resolution radar images of ships, and appear as a two dimensional topology of peaks with various amplitudes. The performance comparisons showed that the HNN does not perform as well as the other neural networks when using the same test data. However, modification of the data to make it appear more Gaussian distributed, improved the performance of the network. The HNN performs best if the data is completely Gaussian distributed.

  14. Oral zinc supplementation restore high molecular weight seminal zinc binding protein to normal value in Iraqi infertile men

    Directory of Open Access Journals (Sweden)

    Hadwan Mahmoud

    2012-11-01

    Full Text Available Abstract Background Zinc in human seminal plasma is divided into three types of ligands which are high (HMW, intermediate (IMW, and low molecular weight ligands (LMW. The present study was aimed to study the effect of Zn supplementation on the quantitative and qualitative characteristics of semen along with Zinc Binding Protein levels in the seminal plasma in asthenozoospermic patients. Methods Semen samples were obtained from 37 fertile and 37 asthenozoospermic infertile men with matched age. The subfertile group was treated with zinc sulfate, every participant took two capsules per day for three months (each one 220mg. Semen samples were obtained (before and after zinc sulfate supplementation. After liquefaction seminal fluid at room temperature, routine semen analyses were performed. For determination of the amount of zinc binding proteins, the gel filtration of seminal plasma on Sephadex G-75 was performed. All the fractions were investigated for protein and for zinc concentration by atomic absorption spectrophotometry. Evaluation of chromatograms was made directly from the zinc concentration in each fraction. Results A significant high molecular weight zinc binding ligands percentage (HMW-Zn % was observed in seminal plasma of fertile males compared with subfertile males. However, seminal low molecular weight ligands (LMW-Zn have opposite behavior. The mean value of semen volume, progressive sperm motility percentage and total normal sperm count were increased after zinc sulfate supplementation. Conclusions Zinc supplementation restores HMW-Zn% in seminal plasma of asthenozoospermic subjects to normal value. Zinc supplementation elevates LMW-Zn% in seminal plasma of asthenozoospermic subjects to more than normal value. Trial registration ClinicalTrials.gov identifier NCT01612403

  15. Concurrent repletion of iron and zinc reduces intestinal oxidative damage in iron-and zinc-deficient rats

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To understand the interactions between iron and zinc during absorption in iron- and zinc-deficient rats,and their consequences on intestinal oxidant-antioxidant balance.METHODS: Twenty-four weanling Wistar-Kyoto rats fed an iron- and zinc-deficient diet (< 6.5 mg Fe and 4.0 mg Zn/kg diet) for 4 wk were randomly divided into three groups (n = 8, each) and orally gavaged with 4 mg iron, 3.3 mg zinc, or 4 mg iron + 3.3 mg zinc for 2wk. At the last day of repletion, 3 h before the animals were sacrificed, they received either 37 mBq of 55Fe or 65Zn, to study their localization in the intestine, using microautoradiography. Hemoglobin, iron and zinc content in plasma and liver were measured as indicators of iron and zinc status. Duodenal sections were used for immunochemical staining of ferritin and metallothionein.Duodenal homogenates (mitochondrial and cytosolic fractions), were used to assess aconitase activity,oxidative stress, functional integrity and the response of antioxidant enzymes.RESULTS: Concurrent repletion of iron- and zinc-deficient rats showed reduced localization of these minerals compared to rats that were teated with iron or zinc alone;these data provide evidence for antagonistic interactions.This resulted in reduced formation of lipid and protein oxidation products and better functional integrity of the intestinal mucosa. Further, combined repletion lowered iron-associated aconitase activity and ferritin expression,but significantly elevated metallothionein and glutathione levels in the intestinal mucosa. The mechanism of interactions during combined supplementation and its subsequent effects appeared to be due to through modulation of cytosolic aconitase, which in turn influenced the labile iron pool and metallothionein levels, and hence reduced intestinal oxidative damage.CONCLUSION: Concurrent administration of iron and zinc corrects iron and zinc deficiency, and also reduces the intestinal oxidative damage associated with iron

  16. Novel synthesis of layered double hydroxides (LDHs) from zinc hydroxide

    Science.gov (United States)

    Meng, Zilin; Zhang, Yihe; Zhang, Qian; Chen, Xue; Liu, Leipeng; Komarneni, Sridhar; Lv, Fengzhu

    2017-02-01

    The most common synthesis methods for layered double hydroxides (LDHs) are co-precipitation and reconstruction, which can have some limitations for application. Here, we report a novel synthesis method for LDHs. We use zinc hydroxide as the precursor to synthesize LDHs phase through a simple transformation process of zinc hydroxide phase. For this transformation process, aluminum can enter into zinc hydroxide and replace zinc quickly to transform it into LDH by creating positive charges in the zinc hydroxide solid phase. The mechanism of LDH formation was through Al3+ reaction first with zinc hydroxide followed by recrystallization of the original structure of zinc hydroxide. Thus, the new process of LDH formation involves a reaction of Al to substitute for Zn and recrystallization leading to LDH and the final pH influences the crystallization of LDHs by this process. In addition, Cr3+ was employed as a trivalent cation for LDH formation to react with zinc hydroxide, which also led to LDH structure.

  17. Zinc corrosion runoff process induced by humid tropical climate

    Energy Technology Data Exchange (ETDEWEB)

    Veleva, L. [Center for Investigation and Advanced Study (CINVESTAV-Merida), Applied Physics Department, Carr. Ant. a Progreso, Km.6, C.P. 97310, Merida, Yuc. (Mexico); Meraz, E. [Universidad Juarez Autonoma de Tabasco, Division Academica de Ingenieria y Arquitectura, Km 1 Carretera Cunduacan-Jalpa de M., A.P. 24, C.P. 86690, Cunduacan, Tabasco (Mexico); Acosta, M. [Universidad Juarez Autonoma de Tabasco, Division Academica de Ciencias Basicas, Km 1 Carretera Cunduacan-Jalpa de M., A.P. 24, C.P. 86690, Cunduacan, Tabasco (Mexico)

    2007-05-15

    Zinc and hot dip galvanized steel are frequently used metals in building application. They have relatively good atmospheric resistance to corrosion, due to its oxidation in air and formation of protective rust on its surface, which acts as barrier between the metal and environment. However, some part of the rust can be dissolved by pluvial precipitations and water condensed on the metal surface. This process, called metal runoff, contributes for zinc dispersion in soils and waters. In order to make accurate estimation of zinc runoff induced by atmosphere in humid tropical climate, samples of pure Zn and hot dip galvanized steel have been exposed in the Gulf of Mexico. The data reveal that this process is strongly influenced by factors which determine the aggressivity of the environment (pluvial precipitations, cycles of dry and rainy periods, atmospheric pollutants, air humidity). High annual rates of zinc runoff (6.5 - 8.5 {+-} 0.30 g Zn m{sup -2}yr{sup -1}) were released, being the runoff 63 - 87% of the zinc corrosion rust. The zinc mass loss has been related to several independent parameters, presenting linear equation, which indicates the air contaminant SO{sub 2} as the major factor controlling the runoff of zinc. The reported results show higher runoff of zinc samples, compared to that of hot dip galvanized steel. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  18. Zinc deficiency alters soybean susceptibility to pathogens and pests

    Science.gov (United States)

    Inadequate plant nutrition and biotic stress are key threats to current and future crop yields. Zinc deficiency and toxicity in major crop plants have been documented, but there is limited information on how pathogen and pest damage may be affected by differing plant zinc levels. In our study, we us...

  19. Lattice dynamical investigations on Zn diffusion in zinc oxide

    Indian Academy of Sciences (India)

    P Vinotha Boorana Lakshmi; K Ramachandran

    2011-04-01

    Zinc self diffusion in bulk zinc oxide is studied by lattice dynamical approach here to get more insight into the diffusion in nano ZnO. The results reveal that only cationic self diffusion is dominant over anionic self diffusion and that too by single vacancy mechanism. The results are compared with the available experiments and discussed.

  20. Metallic zinc exhibits optimal biocompatibility for bioabsorbable endovascular stents.

    Science.gov (United States)

    Bowen, Patrick K; Guillory, Roger J; Shearier, Emily R; Seitz, Jan-Marten; Drelich, Jaroslaw; Bocks, Martin; Zhao, Feng; Goldman, Jeremy

    2015-11-01

    Although corrosion resistant bare metal stents are considered generally effective, their permanent presence in a diseased artery is an increasingly recognized limitation due to the potential for long-term complications. We previously reported that metallic zinc exhibited an ideal biocorrosion rate within murine aortas, thus raising the possibility of zinc as a candidate base material for endovascular stenting applications. This study was undertaken to further assess the arterial biocompatibility of metallic zinc. Metallic zinc wires were punctured and advanced into the rat abdominal aorta lumen for up to 6.5months. This study demonstrated that metallic zinc did not provoke responses that often contribute to restenosis. Low cell densities and neointimal tissue thickness, along with tissue regeneration within the corroding implant, point to optimal biocompatibility of corroding zinc. Furthermore, the lack of progression in neointimal tissue thickness over 6.5months or the presence of smooth muscle cells near the zinc implant suggest that the products of zinc corrosion may suppress the activities of inflammatory and smooth muscle cells.

  1. Biovailability of copper and zinc in pig and cattle slurries

    NARCIS (Netherlands)

    Jakubus, M.; Dach, J.; Starmans, D.A.J.

    2013-01-01

    Slurry is an important source of macronutrients, micro-nutrients and organic matter. Despite the considerable fertilizer value of slurry, it may be abundant in amounts of copper and zinc originating from dietary. The study presents quantitative changes in copper and zinc in individual slurries (pig

  2. EURRECA—Estimating Zinc Requirements for Deriving Dietary Reference Values

    NARCIS (Netherlands)

    Lowe, N.M.M.; Dykes, F.C.; Skinner, A.L.; Patel, S.; Warthon-Medina, M.; Decsi, T.; Fekete, K.; Souverein, O.W.; Dullemeijer, C.; Cavelaars, A.J.E.M.; Serra-Majem, L.; Nissensohn, M.; Bel, S.; Moreno, L.A.; Hermoso, M.; Vollhardt, C.; Berti, C.; Cetin, I.; Gurinovic, M.; Novakovic, R.N.; Harvey, L.J.; Collings, R.; Hall-Moran, V.

    2013-01-01

    Zinc was selected as a priority micronutrient for EURRECA, because there is significant heterogeneity in the Dietary Reference Values (DRVs) across Europe. In addition, the prevalence of inadequate zinc intakes was thought to be high among all population groups worldwide, and the public health conce

  3. EURRECA-Estimating zinc requirements for deriving dietary reference values.

    Science.gov (United States)

    Lowe, Nicola M; Dykes, Fiona C; Skinner, Anna-Louise; Patel, Sujata; Warthon-Medina, Marisol; Decsi, Tamás; Fekete, Katalin; Souverein, Olga W; Dullemeijer, Carla; Cavelaars, Adriënne E; Serra-Majem, Lluis; Nissensohn, Mariela; Bel, Silvia; Moreno, Luis A; Hermoso, Maria; Vollhardt, Christiane; Berti, Cristiana; Cetin, Irene; Gurinovic, Mirjana; Novakovic, Romana; Harvey, Linda J; Collings, Rachel; Hall-Moran, Victoria

    2013-01-01

    Zinc was selected as a priority micronutrient for EURRECA, because there is significant heterogeneity in the Dietary Reference Values (DRVs) across Europe. In addition, the prevalence of inadequate zinc intakes was thought to be high among all population groups worldwide, and the public health concern is considerable. In accordance with the EURRECA consortium principles and protocols, a series of literature reviews were undertaken in order to develop best practice guidelines for assessing dietary zinc intake and zinc status. These were incorporated into subsequent literature search strategies and protocols for studies investigating the relationships between zinc intake, status and health, as well as studies relating to the factorial approach (including bioavailability) for setting dietary recommendations. EMBASE (Ovid), Cochrane Library CENTRAL, and MEDLINE (Ovid) databases were searched for studies published up to February 2010 and collated into a series of Endnote databases that are available for the use of future DRV panels. Meta-analyses of data extracted from these publications were performed where possible in order to address specific questions relating to factors affecting dietary recommendations. This review has highlighted the need for more high quality studies to address gaps in current knowledge, in particular the continued search for a reliable biomarker of zinc status and the influence of genetic polymorphisms on individual dietary requirements. In addition, there is a need to further develop models of the effect of dietary inhibitors of zinc absorption and their impact on population dietary zinc requirements.

  4. Da Xinganling Lead Zinc Smelting Base Commencing the Construction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The construction of the first phase of 150,000- ton lead zinc smelting base project,the largest lead zinc smelting project in Heilongjiang Province,of Da Xinganling Yunye Mining Ltd. officially started on May 24 in Jiagedaqi Indus- trial Park in Da Xinganling Region.

  5. Reversing Sports-Related Iron and Zinc Deficiencies.

    Science.gov (United States)

    Loosli, Alvin R.

    1993-01-01

    Many active athletes do not consume enough zinc or iron, which are important for oxygen activation, electron transport, and injury healing. Subclinical deficiencies may impair performance and impair healing times. People who exercise regularly need counseling about the importance of adequate dietary intake of iron and zinc. (SM)

  6. Zinc nanoparticles in solution by laser ablation technique

    Indian Academy of Sciences (India)

    S C Singh; R Gopal

    2007-06-01

    Colloidal zinc metallic nanoparticles are synthesized using pulsed laser ablation of metal plate in an aqueous solution of suitable surfactant to prevent aggregation. UV-visible absorption, TEM, small angle X-ray diffraction and wide-angle X-ray diffraction are used for the characterization of colloidal zinc metallic nanoparticles. Colloidal nanoparticles are found highly stable for a long time.

  7. Zinc supplementation, production and quality of coffee beans

    Directory of Open Access Journals (Sweden)

    Herminia Emilia Prieto Martinez

    2013-04-01

    Full Text Available Besides its importance in the coffee tree nutrition, there is almost no information relating zinc nutrition and bean quality. This work evaluated the effect of zinc on the coffee yield and bean quality. The experiment was conducted with Coffea arabica L. in "Zona da Mata" region, Minas Gerais, Brazil. Twelve plots were established at random with 4 competitive plants each. Treatments included plants supplemented with zinc (eight plots and control without zinc supplementation (four plots. Plants were subjected to two treatments: zinc supplementation and control. Yield, number of defective beans, beans attacked by berry borers, bean size, cup quality, beans zinc concentration, potassium leaching, electrical conductivity, color index, total tritable acidity, pH, chlorogenic acids contents and ferric-reducing antioxidant activity of beans were evaluated. Zinc positively affected quality of coffee beans, which presented lower percentage of medium and small beans, lower berry borer incidence, lower potassium leaching and electrical conductivity, higher contents of zinc and chlorogenic acids and higher antioxidant activity in comparison with control beans.

  8. Sequestration of zinc oxide by fimbrial designer chelators

    DEFF Research Database (Denmark)

    Kjærgaard, Kristian; Sørensen, Jack K; Schembri, Mark;

    2000-01-01

    , one of the inserts exhibited significant homology to a specific sequence in a putative zinc-containing helicase, which suggests that searches such as this one may aid in identifying binding motifs in nature. The zinc-binding bacteria might have a use in detoxification of metal-polluted water...

  9. Zinc mediated domino elimination-alkylation of methyl 5-iodopentofuranosides

    DEFF Research Database (Denmark)

    Hyldtoft, Lene; Poulsen, Carina Storm; Madsen, Robert

    1999-01-01

    5-Iodopentofuranosides are converted with zinc and allyl/propargyl bromide into dienes/enynes which are further used in carbohydrate annulation reactions.......5-Iodopentofuranosides are converted with zinc and allyl/propargyl bromide into dienes/enynes which are further used in carbohydrate annulation reactions....

  10. Physiology and modelling of zinc allocation in aerobic rice

    NARCIS (Netherlands)

    Jiang, W.

    2008-01-01

    Keywords: Zinc, rice, Oryza sativa, grain, Zn mass concentration, biofortification Zinc (Zn) deficiency in humans is widespread in many regions of the world, especially in the developing world. Rice, the staple food of more than half of the world’s population, is potentially an important source of

  11. Vitamin A, iron and zinc deficiency in Indonesia

    NARCIS (Netherlands)

    Dijkhuizen, M.A.; Wieringa, F.T.

    2001-01-01

    The research described in this thesis was concerned with vitamin A, iron and zinc deficiency in pregnant and lactating women and in infants. The effects of supplementation withβ-carotene, iron and zinc on micronutrient status, growth, pregnancy outcome and immune function, and interactions between m

  12. Chemical and biological rhizosphere interactions in low zinc soils

    NARCIS (Netherlands)

    Duffner, A.

    2014-01-01

    Abstract of the PhD thesis entitled “Chemical and biological rhizosphere interactions in low zinc soils” by Andreas Duffner Soil provides ecosystem services critical for life. The availability of micronutrients, such as zinc (Zn), in soils is an essenti

  13. Treatment of Wilson's disease with zinc: X. Intestinal metallothionein induction.

    Science.gov (United States)

    Yuzbasiyan-Gurkan, V; Grider, A; Nostrant, T; Cousins, R J; Brewer, G J

    1992-09-01

    Oral zinc therapy is effective in controlling copper balance in patients with Wilson's disease and blocks the intestinal absorption of copper, as demonstrated by uptake of copper 64 and copper balance measurements. In this study, 64Cu uptake measurements were concomitantly carried out with intestinal biopsies to investigate the relationship of reduced copper absorption to the levels of intestinal metallothionein in patients with Wilson's disease at different stages of zinc therapy. A pronounced increase in intestinal metallothionein levels and a sharp drop in 64Cu absorption were found 4 to 5 days after the initiation of zinc treatment. Conversely, metallothionein levels decreased and 64Cu uptake increased on the discontinuation of zinc therapy. The data indicate that 64Cu absorption varies as a function of intestinal metallothionein level. Intestinal metallothionein levels were found to correlate linearly with urinary zinc levels, which reflect body zinc status. These findings support our hypothesis that intestinal metallothionein induction mediates decreased copper absorption observed during zinc therapy. The suppressive effect of zinc on copper absorption appears to have a half-life of about 11 days.

  14. Determination of the density of zinc powders for alkaline battery

    Institute of Scientific and Technical Information of China (English)

    Beatriz Ares Tejero; David Guede Carnero

    2007-01-01

    The density of zinc powder for alkaline battery was determined using a pyknometer.The results showed that powders made before the end of 2003 could reach relative densities above 99% of the theoretical density.Investigating the relative volume swelling of electrolysed gels of zinc powders,no evident relation between swelling and pyknometer density was found.

  15. Metallic Zinc Exhibits Optimal Biocompatibility for Bioabsorbable Endovascular Stents

    Science.gov (United States)

    Bowen, Patrick K.; Guillory, Roger J.; Shearier, Emily R.; Seitz, Jan-Marten; Drelich, Jaroslaw; Bocks, Martin; Zhao, Feng; Goldman, Jeremy

    2015-01-01

    Although corrosion resistant bare metal stents are considered generally effective, their permanent presence in a diseased artery is an increasingly recognized limitation due to the potential for long-term complications. We previously reported that metallic zinc exhibited an ideal biocorrosion rate within murine aortas, thus raising the possibility of zinc as a candidate base material for endovascular stenting applications. This study was undertaken to further assess the arterial biocompatibility of metallic zinc. Metallic zinc wires were punctured and advanced into the rat abdominal aorta lumen for up to 6.5 months. This study demonstrated that metallic zinc did not provoke responses that often contribute to restenosis. Low cell densities and neointimal tissue thickness, along with tissue regeneration within the corroding implant, point to optimal biocompatibility of corroding zinc. Furthermore, the lack of progression in neointimal tissue thickness over 6.5 months or the presence of smooth muscle cells near the zinc implant suggest that the products of zinc corrosion may suppress the activities of inflammatory and smooth muscle cells. PMID:26249616

  16. Modulation of zinc toxicity by tissue plasminogen activator.

    Science.gov (United States)

    Siddiq, Mustafa M; Tsirka, Stella E

    2004-01-01

    The tissue plasminogen activator (tPA)-plasmin proteolytic system mediates excitotoxin-induced neurodegeneration in vivo and in cell culture. tPA also confers neuroprotection from zinc toxicity in cell culture through a proteolysis-independent mechanism. This raises two questions: what is this non-enzymatic mechanism, and why tPA does not synergize with zinc to promote neuronal cell death? We show here that zinc binds to tPA and inhibits its activity in a dose-dependent fashion, thus terminating its protease-dependent neurotoxic capacity. We extend the previously reported culture findings to demonstrate that elevated zinc is neurotoxic in vivo, and even more so when tPA is absent. Thus, physiological levels of tPA confer protection from elevated free zinc. Mechanistically, tPA promotes movement of zinc into hippocampal neuron cells through voltage-sensitive Ca(2+) channels and Ca(2+)-permeable AMPA/KA channels. Therefore, zinc and tPA each appear to be able to limit the potential of the other to facilitate neurodegeneration, a reciprocal set of actions that may be critical in the hippocampus where tPA is secreted during the nonpathological conditions of learning and memory at sites known to be repositories of free and sequestered zinc.

  17. Analysis of reaction and transport processes in zinc air batteries

    CERN Document Server

    Schröder, Daniel

    2016-01-01

    This book contains a novel combination of experimental and model-based investigations, elucidating the complex processes inside zinc air batteries. The work presented helps to answer which battery composition and which air-composition should be adjusted to maintain stable and efficient charge/discharge cycling. In detail, electrochemical investigations and X-ray transmission tomography are applied on button cell zinc air batteries and in-house set-ups. Moreover, model-based investigations of the battery anode and the impact of relative humidity, active operation, carbon dioxide and oxygen on zinc air battery operation are presented. The techniques used in this work complement each other well and yield an unprecedented understanding of zinc air batteries. The methods applied are adaptable and can potentially be applied to gain further understanding of other metal air batteries. Contents Introduction on Zinc Air Batteries Characterizing Reaction and Transport Processes Identifying Factors for Long-Term Stable O...

  18. Efficacy of zinc sulfate in reducing unconjugated hyperbilirubinemia in neonates

    Directory of Open Access Journals (Sweden)

    Somayyeh Hashemian

    2014-09-01

    Full Text Available Hyperbilirubinemia is a common disease and unconjugated hyperbilirubinemia has been seen mainly in neonates. Severe form of unconjugated hyperbilirubinemia may cause kernicterus and even death. Conventional treatment for severe unconjugated hyperbilirubinemia consists of phototherapy and exchange transfusion that have several known disadvantages; specially exchange transfusion is associated with a significant morbidity and even mortality. These harmful effects indicate the need to develop alternative pharmacological treatment strategies for unconjugated hyperbilirubinemia. One of these pharmacological agents is zinc salts. Zinc has been shown to lower the bilirubin levels by inhibition of the enterohepatic cycling of unconjugated bilirubin. Oral zinc has been shown to reduce serum unconjugated bilirubin in animals, adolescents and low birth weight neonates. However, studies in healthy term neonates given oral zinc showed no reduction in hyperbilirubinemia based on daily measurement. In order to improve the accuracy, hyperbilirubinemia may be determined based on measurements every hour. More studies are needed to know the effect of zinc in neonatal jaundice.

  19. Interfacial chemistry of zinc anodes for reinforced concrete structures

    Energy Technology Data Exchange (ETDEWEB)

    Covino, B.S. Jr.; Bullard, S.J.; Cramer, S.D.; Holcomb, G.R. [Dept. of Energy, Albany, OR (United States). Albany Research Center; McGill, G.E.; Cryer, C.B. [Oregon Dept. of Transportation, Salem, OR (United States); Stoneman, A. [International Lead Zinc Research Organization, Research Triangle Park, NC (United States); Carter, R.R. [California Dept. of Transportation, Sacramento, CA (United States)

    1997-12-01

    Thermally-sprayed zinc anodes are used in both galvanic and impressed current cathodic protection systems for reinforced concrete structures. The Albany Research Center, in collaboration with the Oregon Department of Transportation, has been studying the effect of electrochemical aging on the bond strength of zinc anodes for bridge cathodic protection systems. Changes in anode bond strength and other anode properties can be explained by the chemistry of the zinc-concrete interface. The chemistry of the zinc-concrete interface in laboratory electrochemical aging studies is compared with that of several bridges with thermal-sprayed zinc anodes and which have been in service for 5 to 10 years using both galvanic and impressed current cathodic protection systems. The bridges are the Cape Creek Bridge on the Oregon coast and the East Camino Undercrossing near Placerville, CA. Also reported are interfacial chemistry results for galvanized steel rebar from the 48 year old Longbird Bridge in Bermuda.

  20. Leaching and recycling of zinc from liquid waste sediments

    Institute of Scientific and Technical Information of China (English)

    PENG Bing; GAO Hui-mei; CHAI Li-yuan; SHU Yu-de

    2008-01-01

    The selective leaching and recovery of zinc in a zinciferous sediment from a synthetic wastewater treatment was investigated. The main composition of the sediment includes 6% zinc and other metal elements such as Ca, Fe, Cu, Mg. The effects of sulfuric acid concentration, temperature, leaching time and the liquid-to-solid ratio on the leaching rate of zinc were studied by single factor and orthogonal experiments. The maximum difference of leaching rate between zinc and iron, 89.85%, was obtained by leaching under 170 g/L H2SO4 in liquid-to-solid ratio 4.2 mL/g at 65 "C for 1 h, and the leaching rates of zinc and iron were 91.20% and 1.35%, respectively.

  1. Behavior of arsenic in hydrometallurgical zinc production and environmental impact

    Directory of Open Access Journals (Sweden)

    Peltekov A.B.

    2014-12-01

    Full Text Available The presence of arsenic in zinc sulphide concentrates is particularly harmful, because it creates problems in zinc electrolysis. The main source of arsenic in non-ferrous metallurgy is arsenopyrite (FeAsS. In oxidative roasting of zinc concentrates, FeAsS oxidizes to arsenic oxides (As2O3, As2O5. In this connection a natural FeAsS was examined, and also the distribution of arsenic in the products of the roasting process, the cycle of sulphuric acid obtaining and the leaching of zinc calcine were studied. The arsenic contamination of soils in the vicinity of nonferrous metals smelter KCM SA, Plovdiv, Bulgaria as a result of zinc and lead productions has been studied.

  2. Synthesis and characterization of fly ash-zinc oxide nanocomposite

    Directory of Open Access Journals (Sweden)

    Kunal Yeole

    2014-04-01

    Full Text Available Fly ash, generated in thermal power plants, is recognized as an environmental pollutant. Thus, measures are required to be undertaken to dispose it in an environmentally friendly method. In this paper an attempt is made to coat zinc oxide nano-particles on the surface of fly ash by a simple and environmentally friendly facile chemical method, at room temperature. Zinc oxide may serve as effective corrosion inhibitor by providing sacrificial protection. Concentration of fly ash was varied as 5, 10 and 15 (w/w % of zinc oxide. It was found that crystallinity increased, whereas particle size, specific gravity and oil absorption value decreased with increased concentration of fly ash in zinc oxide, which is attributed to the uniform distribution of zinc oxide on the surface of fly ash. These nanocomposites can potentially be used in commercial applications as additive for anticorrosion coatings.

  3. Isothermal corrosion Fe3Si alloy in liquid zinc

    Institute of Scientific and Technical Information of China (English)

    Wen jun Wang; Junping Lin; Yanli Wang; Guoliang Chen

    2007-01-01

    The isothermal corrosion testing,microscopic examination and the performance of Fe3Si alloy as materials of construction for bath hardware in continuous hot-dipping lines were studied.The corrosion of Fe3Si alloy in molten zinc was controlled by attacking the grain boundaries preferentially.Aluminum reacted with iron of Fe3Si alloy firstly while the samples were immersed in molten zinc,although aluminum contents in the molten zinc were very low.The phase of reaction product was thought to be Fe2Al5.The corrosion rate of the Fe3Si alloy in molten zinc was determined to be approximately 2.9×10-3 mm/h,therefore the liquid zinc corrosion resistance of Fe3Si alloy was very weak.

  4. SERUM ZINC LEVEL IN PATIENTS WITH SIMPLE FEBRILE SEIZURE

    Directory of Open Access Journals (Sweden)

    Farhad HEYDARIAN

    2010-10-01

    Full Text Available ObjectiveTo evaluate the serum zinc level of the patients with simple febrile seizure and compare them with febrile children without seizure.Materials & MethodsThis prospective case - control study was performed on 60 patients aged 6 months to 6 years from Apr. 2009 to Jan.2010 in Ghaem, Imam Reza and Dr. Sheikh Hospitals in Mashhad. The serum zinc level was assessed and compared between the cases (30 individuals who suffered from simple febrile seizure and the controls (30 individuals who had fever without seizure.ResultsMean serum zinc level was 663.7 µg /l and 758.33  µg /l in the case group and the control group, respectively (PConclusionIt was revealed that the serum level of zinc was significantly lower in children with simple febrile seizure in comparison with febrile children without seizure.Keywords: Simple febrile seizure, children, zinc, CSF (cerebrospinal fluid

  5. Zinc in hair and urine of paediatric patients.

    Science.gov (United States)

    van Wouwe, J P; de Wolff, F A; van Gelderen, H H

    1986-02-28

    Zinc concentrations in hair and urine were measured in groups of children varying in one condition - short stature, or after prolonged upper respiratory infection, or during non-infectious diarrhea, or while on chemotherapy for acute lymphatic leukaemia and in healthy controls. As compared with controls, hair zinc was significantly low after respiratory infection (p less than 0.0001) and high in short stature (p less than 0.01). Urinary zinc was increased during initial chemotherapy (p less than 0.001) and diarrhea (p less than 0.02). It is shown that zinc deficiency occurs in one of the common symptoms in paediatric medicine, namely upper respiratory tract infection. The high overlap (34-88%) proves hair and urine zinc to be of no use for reliable individual diagnostic statements.

  6. Multigradient for Neural Networks for Equalizers

    Directory of Open Access Journals (Sweden)

    Chulhee Lee

    2003-06-01

    Full Text Available Recently, a new training algorithm, multigradient, has been published for neural networks and it is reported that the multigradient outperforms the backpropagation when neural networks are used as a classifier. When neural networks are used as an equalizer in communications, they can be viewed as a classifier. In this paper, we apply the multigradient algorithm to train the neural networks that are used as equalizers. Experiments show that the neural networks trained using the multigradient noticeably outperforms the neural networks trained by the backpropagation.

  7. Neural network regulation driven by autonomous neural firings

    Science.gov (United States)

    Cho, Myoung Won

    2016-07-01

    Biological neurons naturally fire spontaneously due to the existence of a noisy current. Such autonomous firings may provide a driving force for network formation because synaptic connections can be modified due to neural firings. Here, we study the effect of autonomous firings on network formation. For the temporally asymmetric Hebbian learning, bidirectional connections lose their balance easily and become unidirectional ones. Defining the difference between reciprocal connections as new variables, we could express the learning dynamics as if Ising model spins interact with each other in magnetism. We present a theoretical method to estimate the interaction between the new variables in a neural system. We apply the method to some network systems and find some tendencies of autonomous neural network regulation.

  8. Galvanizing action: conclusions and next steps for mainstreaming zinc interventions in public health programs.

    Science.gov (United States)

    Brown, Kenneth H; Baker, Shawn K

    2009-03-01

    This paper summarizes the results of the foregoing reviews of the impact of different intervention strategies designed to enhance zinc nutrition, including supplementation, fortification, and dietary diversification or modification. Current evidence indicates a beneficial impact of such interventions on zinc status and zinc-related functional outcomes. Preventive zinc supplementation reduces the incidence of diarrhea and acute lower respiratory tract infection among young children, decreases mortality of children over 12 months of age, and increases growth velocity. Therapeutic zinc supplementation during episodes of diarrhea reduces the duration and severity of illness. Zinc fortification increases zinc intake and total absorbed zinc, and recent studies are beginning to confirm a positive impact of zinc fortification on indicators of population zinc status. To assist with the development of zinc intervention programs, more information is needed on the prevalence of zinc deficiency in different countries, and rigorous evaluations of the effectiveness of large-scale zinc intervention programs should be planned. Recommended steps for scaling up zinc intervention programs, with or without other micronutrients, are described. In summary, there is now clear evidence of the benefit of selected interventions to reduce the risk of zinc deficiency, and a global commitment is urgently needed to conduct systematic assessments of population zinc status and to develop interventions to control zinc deficiency in the context of existing public health and nutrition programs.

  9. Trace elements in human physiology and pathology: zinc and metallothioneins.

    Science.gov (United States)

    Tapiero, Haim; Tew, Kenneth D

    2003-11-01

    Zinc is one of the most abundant nutritionally essential elements in the human body. It is found in all body tissues with 85% of the whole body zinc in muscle and bone, 11% in the skin and the liver and the remaining in all the other tissues. In multicellular organisms, virtually all zinc is intracellular, 30-40% is located in the nucleus, 50% in the cytoplasm, organelles and specialized vesicles (for digestive enzymes or hormone storage) and the remainder in the cell membrane. Zinc intake ranges from 107 to 231 micromol/d depending on the source, and human zinc requirement is estimated at 15 mg/d. Zinc has been shown to be essential to the structure and function of a large number of macromolecules and for over 300 enzymic reactions. It has both catalytic and structural roles in enzymes, while in zinc finger motifs, it provides a scaffold that organizes protein sub-domains for the interaction with either DNA or other proteins. It is critical for the function of a number of metalloproteins, inducing members of oxido-reductase, hydrolase ligase, lyase family and has co-activating functions with copper in superoxide dismutase or phospholipase C. The zinc ion (Zn(++)) does not participate in redox reactions, which makes it a stable ion in a biological medium whose potential is in constant flux. Zinc ions are hydrophilic and do not cross cell membranes by passive diffusion. In general, transport has been described as having both saturable and non-saturable components, depending on the Zn(II) concentrations involved. Zinc ions exist primarily in the form of complexes with proteins and nucleic acids and participate in all aspects of intermediary metabolism, transmission and regulation of the expression of genetic information, storage, synthesis and action of peptide hormones and structural maintenance of chromatin and biomembranes.

  10. Oral Zinc Supplementation for the Treatment of Acute Diarrhea

    Directory of Open Access Journals (Sweden)

    Sh Gheibi

    2014-04-01

    Full Text Available Introduction: Diarrheal diseases are a serious health problem and important causes of growth retardation and death in the developing world, especially those of prolonged duration. Since diarrhea is constantly found in children with zinc deficiency, very studies supported zinc supplements beneficial on the duration and severity of diarrhea among children. We review the impact of zinc effects on diarrhea in South-West Asia to update the evidences and to assess its effect on the global burden of diarrhea.   Materials and Methods: We conduct a systematic review through January 2014, for randomized controlled trials relevant to effect of zinc on diarrhea in children. We searched the MeSH terms zinc, acute gastroenteritis and children from various databases of Cochrane Library and PubMed, then clinical trials done in South-West Asia, selected for making written. Results: In recent years, several studies have reported the therapeutic effect of zinc supplementation on diarrheal diseases that was beneficial on decreased episode duration, stool output, stool frequency, hospitalization duration. In some countries in West Asia such as Lebanon, Israel, Saudi Arabia and Iran in clinical trials showed a faster improvement in acute gastroenteritis in children less than five years. But in some countries, such as Turkey, this effect was not significant.   Conclusions: Oral zinc supplementation significantly decreases diarrhea duration and has a greater effect on malnourished children. Zinc supplementation seems to be an appropriate public health strategy, mainly in areas of endemic deficiencies. Global attempts should is increased to support recommended regimen of therapeutic zinc by WHO in all areas. Keywords: Acute Gastroenteritis, Children, Zinc, South-West Asia.  

  11. Pancreatitis in wild zinc-poisoned waterfowl

    Science.gov (United States)

    Sileo, Louis; Beyer, W. Nelson; Mateo, Rafael

    2003-01-01

    Four waterfowl were collected in the TriState Mining District (Oklahoma, Kansas and Missouri, USA), an area known to be contaminated with lead, cadmium and zinc (Zn). They were part of a larger group of 20 waterfowl collected to determine the exposure of birds to metal contamination at the site. The four waterfowl (three Branta canadensis, one Anas platyrhynchos) had mild to severe degenerative abnormalities of the exocrine pancreas, as well as tissue (pancreas, liver) concentrations of Zn that were considered toxic. The mildest condition was characterized by generalized atrophy of exocrine cells that exhibited cytoplasmic vacuoles and a relative lack of zymogen. The most severe condition was characterized by acini with distended lumens and hyperplastic exocrine tissue that completely lacked zymogen; these acini were widely separated by immature fibrous tissue. Because the lesions were nearly identical to the lesions reported in chickens and captive waterfowl that had been poisoned with ingested Zn, and because the concentrations of Zn in the pancreas and liver of the four birds were consistent with the concentrations measured in Zn-poisoned birds, we concluded that these waterfowl were poisoned by Zn. This may be the first reported case of zinc poisoning in free-ranging wild birds poisoned by environmental Zn.

  12. Zinc transporters and dysregulated channels in cancers

    Science.gov (United States)

    Pan, Zui; Choi, Sangyong; Ouadid-Ahidouch, Halima; Yang, Jin-Ming; Beattie, John H.; Korichneva, Irina

    2016-01-01

    As a nutritionally essential metal ion, zinc (Zn) not only constitutes a structural element for more than 3000 proteins but also plays important regulatory functions in cellular signal transduction. Zn homeostasis is tightly controlled by regulating the flux of Zn across cell membranes through specific transporters, i.e. ZnT and ZIP family proteins. Zn deficiency and malfunction of Zn transporters have been associated with many chronic diseases including cancer. However, the mechanisms underlying Zn regulatory functions in cellular signaling and their impact on the pathogenesis and progression of cancers remain largely unknown. In addition to these acknowledged multifunctions, Zn modulates a wide range of ion channels that in turn may also play an important role in cancer biology. The goal of this review is to propose how zinc deficiency, through modified Zn homeostasis, transporter activity and the putative regulatory function of Zn can influence ion channel activity, and thereby contribute to carcinogenesis and tumorigenesis. This review intends to stimulate interest in, and support for research into the understanding of Zn-modulated channels in cancers, and to search for novel biomarkers facilitating effective clinical stratification of high risk cancer patients as well as improved prevention and therapy in this emerging field. PMID:27814637

  13. Solar thermal production of zinc: Program strategy

    Energy Technology Data Exchange (ETDEWEB)

    Steinfeld, A.; Weidenkaff, A.; Moeller, S.; Palumbo, R. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    The solar thermal production of zinc is considered for the conversion of solar energy into storable and transportable chemical fuels. The ultimate objective is to develop a technically and economically viable technology that can produce solar zinc. The program strategy for achieving such a goal involves research on two paths: a direct path via the solar thermal splitting of ZnO in the absence of fossil fuels, and an indirect path via the solar carbothermal/CH{sub 4}-thermal reduction of Zn O, with fossil fuels (coke or natural gas) as chemical reducing agents. Both paths make use of concentrated solar energy for high-temperature process heat. The direct path brings us to the complete substitution of fossil fuels with solar fuels for a sustainable energy supply system. The indirect path creates a link between today`s fossil-fuel-based technology and tomorrow`s solar chemical technology and builds bridges between present and future energy economies. (author) 1 fig., 15 refs.

  14. Zinc oxide: Connecting theory and experiment

    Directory of Open Access Journals (Sweden)

    Dejan Zagorac

    2013-09-01

    Full Text Available Zinc oxide (ZnO is a material with a great variety of industrial applications including high heat capacity, thermal conductivity and temperature stability. Clearly, it would be of great importance to find new stable and/or metastable modifications of zinc oxide, and investigate the influence of pressure and/or temperature on these structures, and try to connect theoretical results to experimental observations. In order to reach this goal, we performed several research studies, using modern theoretical methods. We have predicted possible crystal structures for ZnO using simulated annealing (SA, followed by investigations of the barrier structure using the threshold algorithm (TA. Finally, we have performed calculations using the prescribed path algorithm (PP, where connections between experimental structures on the energy landscape, and in particular transition states, were investigated in detail. The results were in good agreement with previous theoretical and experimental observations, where available, and we have found several additional (metastable modifications at standard, elevated and negative pressures. Furthermore, we were able to gain new insight into synthesis conditions for the various ZnO modifications and to connect our results to the actual synthesis and transformation routes.

  15. Serum concentration of copper, zinc, iron, and cobalt and the copper/zinc ratio in horses with equine herpesvirus-1.

    Science.gov (United States)

    Yörük, Ibrahim; Deger, Yeter; Mert, Handan; Mert, Nihat; Ataseven, Veysel

    2007-07-01

    The serum concentrations of copper, zinc, iron, and cobalt and copper/zinc ratio were investigated in horses infected with equine herpesvirus-1 (EHV-1). Nine horses were naturally infected with the virus and nine healthy horses served as controls. The concentrations of copper, zinc, iron, and cobalt were determined spectrophotometrically in the blood serum of all horses. The results were (expressed in micrograms per deciliters) copper 2.80 +/- 0.34 vs 1.12 +/- 0.44, zinc 3.05 +/- 0.18 vs 0.83 +/- 0.06, iron 2.76 +/- 0.17 vs 3.71 +/- 0.69, cobalt 0.19 +/- 0.37 vs 0.22 +/- 0.45, and copper/zinc ratio 0.72 +/- 0.38 vs 1.41 +/- 0.36 for control vs infected group, respectively. In conclusion, copper and zinc concentrations of the infected group were lower than the control group (p copper/zinc ratio of the infected group were higher than the control group (p cobalt concentration was not found to be statistically different between two groups. It might be emphasized that copper/zinc ratio was significantly affected by the EHV-1 infection, so it could be taken into consideration during the course of infection.

  16. Stunting and zinc deficiency among primary school children in rural areas with low soil zinc concentrations in Jiangsu Province, China

    NARCIS (Netherlands)

    Qin, Yu; Boonstra, A.; Zhao, J.; Wu, M.; Hu, X.; Kok, F.J.

    2009-01-01

    OBJECTIVE: To assess stunting and zinc deficiency among primary school children in north rural area of Jiangsu Province with low soil zinc concentrations, eastern part of China. METHODS: Two data collection rounds were conducted. In the first data collection round, 2268 primary school children aged

  17. Modeling the temporal variability of zinc concentrations in zinc roof runoff-experimental study and uncertainty analysis.

    Science.gov (United States)

    Sage, Jérémie; El Oreibi, Elissar; Saad, Mohamed; Gromaire, Marie-Christine

    2016-08-01

    This study investigates the temporal variability of zinc concentrations from zinc roof runoff. The influence of rainfall characteristics and dry period duration is evaluated by combining laboratory experiment on small zinc sheets and in situ measurements under real weather conditions from a 1.6-m(2) zinc panel. A reformulation of a commonly used conceptual runoff quality model is introduced and its ability to simulate the evolution of zinc concentrations is evaluated. A systematic and sharp decrease from initially high to relatively low and stable zinc concentrations after 0.5 to 2 mm of rainfall is observed for both experiments, suggesting that highly soluble corrosion products are removed at early stages of runoff. A moderate dependence between antecedent dry period duration and the magnitude of zinc concentrations at the beginning of a rain event is evidenced. Contrariwise, results indicate that concentrations are not significantly influenced by rainfall intensities. Simulated rainfall experiment nonetheless suggests that a slight effect of rainfall intensities may be expected after the initial decrease of concentrations. Finally, this study shows that relatively simple conceptual runoff quality models may be adopted to simulate the variability of zinc concentrations during a rain event and from a rain event to another.

  18. Selective Manipulation of Neural Circuits.

    Science.gov (United States)

    Park, Hong Geun; Carmel, Jason B

    2016-04-01

    Unraveling the complex network of neural circuits that form the nervous system demands tools that can manipulate specific circuits. The recent evolution of genetic tools to target neural circuits allows an unprecedented precision in elucidating their function. Here we describe two general approaches for achieving circuit specificity. The first uses the genetic identity of a cell, such as a transcription factor unique to a circuit, to drive expression of a molecule that can manipulate cell function. The second uses the spatial connectivity of a circuit to achieve specificity: one genetic element is introduced at the origin of a circuit and the other at its termination. When the two genetic elements combine within a neuron, they can alter its function. These two general approaches can be combined to allow manipulation of neurons with a specific genetic identity by introducing a regulatory gene into the origin or termination of the circuit. We consider the advantages and disadvantages of both these general approaches with regard to specificity and efficacy of the manipulations. We also review the genetic techniques that allow gain- and loss-of-function within specific neural circuits. These approaches introduce light-sensitive channels (optogenetic) or drug sensitive channels (chemogenetic) into neurons that form specific circuits. We compare these tools with others developed for circuit-specific manipulation and describe the advantages of each. Finally, we discuss how these tools might be applied for identification of the neural circuits that mediate behavior and for repair of neural connections.

  19. Neural recording and modulation technologies

    Science.gov (United States)

    Chen, Ritchie; Canales, Andres; Anikeeva, Polina

    2017-01-01

    In the mammalian nervous system, billions of neurons connected by quadrillions of synapses exchange electrical, chemical and mechanical signals. Disruptions to this network manifest as neurological or psychiatric conditions. Despite decades of neuroscience research, our ability to treat or even to understand these conditions is limited by the capability of tools to probe the signalling complexity of the nervous system. Although orders of magnitude smaller and computationally faster than neurons, conventional substrate-bound electronics do not recapitulate the chemical and mechanical properties of neural tissue. This mismatch results in a foreign-body response and the encapsulation of devices by glial scars, suggesting that the design of an interface between the nervous system and a synthetic sensor requires additional materials innovation. Advances in genetic tools for manipulating neural activity have fuelled the demand for devices that are capable of simultaneously recording and controlling individual neurons at unprecedented scales. Recently, flexible organic electronics and bio- and nanomaterials have been developed for multifunctional and minimally invasive probes for long-term interaction with the nervous system. In this Review, we discuss the design lessons from the quarter-century-old field of neural engineering, highlight recent materials-driven progress in neural probes and look at emergent directions inspired by the principles of neural transduction.

  20. VLSI implementation of neural networks.

    Science.gov (United States)

    Wilamowski, B M; Binfet, J; Kaynak, M O

    2000-06-01

    Currently, fuzzy controllers are the most popular choice for hardware implementation of complex control surfaces because they are easy to design. Neural controllers are more complex and hard to train, but provide an outstanding control surface with much less error than that of a fuzzy controller. There are also some problems that have to be solved before the networks can be implemented on VLSI chips. First, an approximation function needs to be developed because CMOS neural networks have an activation function different than any function used in neural network software. Next, this function has to be used to train the network. Finally, the last problem for VLSI designers is the quantization effect caused by discrete values of the channel length (L) and width (W) of MOS transistor geometries. Two neural networks were designed in 1.5 microm technology. Using adequate approximation functions solved the problem of activation function. With this approach, trained networks were characterized by very small errors. Unfortunately, when the weights were quantized, errors were increased by an order of magnitude. However, even though the errors were enlarged, the results obtained from neural network hardware implementations were superior to the results obtained with fuzzy system approach.

  1. Effects of Dietary Zinc Pectin Oligosaccharides Chelate Supplementation on Growth Performance, Nutrient Digestibility and Tissue Zinc Concentrations of Broilers.

    Science.gov (United States)

    Wang, Zhongcheng; Yu, Huimin; Wu, Xuezhuang; Zhang, Tietao; Cui, Hu; Wan, Chunmeng; Gao, Xiuhua

    2016-10-01

    The experiment was conducted to investigate the effects of zinc pectin oligosaccharides (Zn-POS) chelate on growth performance, nutrient digestibility, and tissue zinc concentrations of Arbor Acre broilers aged from 1 to 42 days. A total of 576 1-day-old broilers were randomly assigned into 4 groups with 9 replicates per group and 16 chicks per replicate. Chicks were fed either a basal diet (control) or basal diet supplemented with Zn-POS at 300 (Zn-POS-300), 600 (Zn-POS-600), or 900 mg/kg (Zn-POS-900), respectively, for 42 days. A 3-day metabolism trial was conducted during the last week of the experiment feeding. The average daily gain and the average daily feed intake of Zn-POS-600 were significantly higher (P zinc concentrations (P zinc concentrations (P zinc concentrations in liver and pancreas of broilers.

  2. Horizontal gene transfer of zinc and non-zinc forms of bacterial ribosomal protein S4

    Directory of Open Access Journals (Sweden)

    Luthey-Schulten Zaida

    2009-07-01

    Full Text Available Abstract Background The universal ribosomal protein S4 is essential for the initiation of small subunit ribosomal assembly and translational accuracy. Being part of the information processing machinery of the cell, the gene for S4 is generally thought of as being inherited vertically and has been used in concatenated gene phylogenies. Here we report the evolution of ribosomal protein S4 in relation to a broad sharing of zinc/non-zinc forms of the gene and study the scope of horizontal gene transfer (HGT of S4 during bacterial evolution. Results In this study we present the complex evolutionary history of ribosomal protein S4 using 660 bacterial genomes from 16 major bacterial phyla. According to conserved characteristics in the sequences, S4 can be classified into C+ (zinc-binding and C- (zinc-free variants, with 26 genomes (mainly from the class Clostridia containing genes for both. A maximum likelihood phylogenetic tree of the S4 sequences was incongruent with the standard bacterial phylogeny, indicating a departure from strict vertical inheritance. Further analysis using the genome content near the S4 genes, which are usually located in a conserved gene cluster, showed not only that HGT of the C- gene had occurred at various stages of bacterial evolution, but also that both the C- and C+ genes were present before the individual phyla diverged. To explain the latter, we theorize that a gene pool existed early in bacterial evolution from which bacteria could sample S4 gene variants, according to environmental conditions. The distribution of the C+/- variants for seven other zinc-binding ribosomal proteins in these 660 bacterial genomes is consistent with that seen for S4 and may shed light on the evolutionary pressures involved. Conclusion The complex history presented for "core" protein S4 suggests the existence of a gene pool before the emergence of bacterial lineages and reflects the pervasive nature of HGT in subsequent bacterial evolution

  3. Friedreich's ataxia causes redistribution of iron, copper, and zinc in the dentate nucleus.

    Science.gov (United States)

    Koeppen, Arnulf H; Ramirez, R Liane; Yu, Devin; Collins, Sarah E; Qian, Jiang; Parsons, Patrick J; Yang, Karl X; Chen, Zewu; Mazurkiewicz, Joseph E; Feustel, Paul J

    2012-12-01

    , metallothionein (MT)-positive processes were more abundant than normal and contributed to the gliosis of the DN. The isoforms of MT, MT-1/2, and brain-specific MT-3 displayed only limited co-localization with glial fibrillary acidic protein. The results suggest that MT can provide effective protection against endogenous Cu and Zn toxicity in FRDA, similar to the neuroprotective sequestration of Fe in holoferritin.

  4. Principles of neural information processing

    CERN Document Server

    Seelen, Werner v

    2016-01-01

    In this fundamental book the authors devise a framework that describes the working of the brain as a whole. It presents a comprehensive introduction to the principles of Neural Information Processing as well as recent and authoritative research. The books´ guiding principles are the main purpose of neural activity, namely, to organize behavior to ensure survival, as well as the understanding of the evolutionary genesis of the brain. Among the developed principles and strategies belong self-organization of neural systems, flexibility, the active interpretation of the world by means of construction and prediction as well as their embedding into the world, all of which form the framework of the presented description. Since, in brains, their partial self-organization, the lifelong adaptation and their use of various methods of processing incoming information are all interconnected, the authors have chosen not only neurobiology and evolution theory as a basis for the elaboration of such a framework, but also syst...

  5. Neural networks and statistical learning

    CERN Document Server

    Du, Ke-Lin

    2014-01-01

    Providing a broad but in-depth introduction to neural network and machine learning in a statistical framework, this book provides a single, comprehensive resource for study and further research. All the major popular neural network models and statistical learning approaches are covered with examples and exercises in every chapter to develop a practical working understanding of the content. Each of the twenty-five chapters includes state-of-the-art descriptions and important research results on the respective topics. The broad coverage includes the multilayer perceptron, the Hopfield network, associative memory models, clustering models and algorithms, the radial basis function network, recurrent neural networks, principal component analysis, nonnegative matrix factorization, independent component analysis, discriminant analysis, support vector machines, kernel methods, reinforcement learning, probabilistic and Bayesian networks, data fusion and ensemble learning, fuzzy sets and logic, neurofuzzy models, hardw...

  6. Chronic but not acute antidepresant treatment alters serum zinc/copper ratio under pathological/zinc-deficient conditions in mice.

    Science.gov (United States)

    Mlyniec, K; Ostachowicz, B; Krakowska, A; Reczynski, W; Opoka, W; Nowak, G

    2014-10-01

    Depression is the leading psychiatric disorder with a high risk of morbidity and mortality. Clinical studies report lower serum zinc in depressed patients, suggesting a strong link between zinc and mood disorders. Also copper as an antagonistic element to zinc seems to play a role in depression, where elevated concentration is observed. In the present study we investigated serum copper and zinc concentration after acute or chronic antidepressant (AD) treatment under pathological/zinc-deficient conditions. Zinc deficiency in mice was induced by a special diet administered for 6 weeks (zinc adequate diet - ZnA, contains 33.5 mgZn/kg; zinc deficient diet - ZnD, contains 0.2 mgZn/kg). Animals received acute or chronically saline (control), imipramine, escitalopram, reboxetine or bupropion. To evaluate changes in serum copper and zinc concentrations the total reflection X-ray fluorescence (TXRF) and flame atomic absorption spectrometry (FAAS) was performed. In ZnD animals serum zinc level was reduced after acute ADs treatment (similarly to vehicle treatment), however, as demonstrated in the previous study after chronic ADs administration no differences between both ZnA and ZnD groups were observed. Acute ADs in ZnD animals caused different changes in serum copper concentration with no changes after chronic ADs treatment. The calculated serum Zn/Cu ratio is reduced in ZnD animals (compared to ZnA subjects) treated with saline (acutely or chronically) and in animals treated acutely with ADs. However, chronic treatment with ADs normalized (by escitalopram, reboxetine or bupropion) or increased (by imipramine) this Zn/Cu ratio. Observed in this study normalization of serum Zn/Cu ratio in depression-like conditions by chronic (but not acute) antidepressants suggest that this ratio may be consider as a marker of depression or treatment efficacy.

  7. Comparison of zinc-probiotic combination theraphy to zinc theraphy alone in reducing the severity of acute diarrhea

    Directory of Open Access Journals (Sweden)

    Muhammad Hatta

    2011-01-01

    Full Text Available Background Although the incidence of diarrhea in Indonesia has declined in the last five years, the mortality rate in children under five years old is still high. Therefore, appropriate and comprehensive management of diarrhea is essential. There have been many studies on the role of zinc therapy and probiotic therapy in reducing the severity of acute diarrhea, but not many studies have compared the use of a combination of the two therapies to zinc therapy alone. Objective To compare the efficacy of zinc-probiotic combination therapy to zinc alone in reducing the severity of acute diarrhea. Methods We conducted a randomized, open-label, controlled trial from July 2009 to January 2010 in Adam Malik Hospital and Pirngadi Hospital , Medan. Children aged between 1 month and 5 years who met the criteria were divided into two groups. Group I recieved zinc sulphate (aged 6 months: 20mg/day combined with heat-killed Lactobacillus acidophilus (3x1010 CFU/day for 10 days. zinc sulphate at the same dosage as group I. Measurement of disease severity was based on the frequency of diarrhea (times/day and the duration of diarrhea (hours after initial drug consumption. Results Eighty subjects were enrolled, randomised, and divided equally into two groups. 40 children received zinc-probiotic in combination (group I and the remainder (group II received zinc alone. We observed significant differences in frequency of diarrhea (2.1 vs 3.1 times/day, P= 0.001, 95%CI-1.62 to -0.49, and duration of diarrhea (52.1 vs 72.6 hours, P=0.001, 95%CI-30.91 to -10.18 in the two groups. Conclusion Combination of zinc-probiotic therapy was more effective in reducing the severity of acute diarrhea than zinc therapy alone in children under five years of age. [Paediatr Indones. 2011;51:1-6].

  8. Using Graph Components Derived from an Associative Concept Dictionary to Predict fMRI Neural Activation Patterns that Represent the Meaning of Nouns.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Akama

    Full Text Available In this study, we introduce an original distance definition for graphs, called the Markov-inverse-F measure (MiF. This measure enables the integration of classical graph theory indices with new knowledge pertaining to structural feature extraction from semantic networks. MiF improves the conventional Jaccard and/or Simpson indices, and reconciles both the geodesic information (random walk and co-occurrence adjustment (degree balance and distribution. We measure the effectiveness of graph-based coefficients through the application of linguistic graph information for a neural activity recorded during conceptual processing in the human brain. Specifically, the MiF distance is computed between each of the nouns used in a previous neural experiment and each of the in-between words in a subgraph derived from the Edinburgh Word Association Thesaurus of English. From the MiF-based information matrix, a machine learning model can accurately obtain a scalar parameter that specifies the degree to which each voxel in (the MRI image of the brain is activated by each word or each principal component of the intermediate semantic features. Furthermore, correlating the voxel information with the MiF-based principal components, a new computational neurolinguistics model with a network connectivity paradigm is created. This allows two dimensions of context space to be incorporated with both semantic and neural distributional representations.

  9. Estimating the global prevalence of zinc deficiency: results based on zinc availability in national food supplies and the prevalence of stunting.

    Directory of Open Access Journals (Sweden)

    K Ryan Wessells

    Full Text Available BACKGROUND: Adequate zinc nutrition is essential for adequate growth, immunocompetence and neurobehavioral development, but limited information on population zinc status hinders the expansion of interventions to control zinc deficiency. The present analyses were conducted to: (1 estimate the country-specific prevalence of inadequate zinc intake; and (2 investigate relationships between country-specific estimated prevalence of dietary zinc inadequacy and dietary patterns and stunting prevalence. METHODOLOGY AND PRINCIPAL FINDINGS: National food balance sheet data were obtained from the Food and Agriculture Organization of the United Nations. Country-specific estimated prevalence of inadequate zinc intake were calculated based on the estimated absorbable zinc content of the national food supply, International Zinc Nutrition Consultative Group estimated physiological requirements for absorbed zinc, and demographic data obtained from United Nations estimates. Stunting data were obtained from a recent systematic analysis based on World Health Organization growth standards. An estimated 17.3% of the world's population is at risk of inadequate zinc intake. Country-specific estimated prevalence of inadequate zinc intake was negatively correlated with the total energy and zinc contents of the national food supply and the percent of zinc obtained from animal source foods, and positively correlated with the phytate: zinc molar ratio of the food supply. The estimated prevalence of inadequate zinc intake was correlated with the prevalence of stunting (low height-for-age in children under five years of age (r = 0.48, P<0.001. CONCLUSIONS AND SIGNIFICANCE: These results, which indicate that inadequate dietary zinc intake may be fairly common, particularly in Sub-Saharan Africa and South Asia, allow inter-country comparisons regarding the relative likelihood of zinc deficiency as a public health problem. Data from these analyses should be used to determine

  10. Iron and zinc supplementation improved iron and zinc status, but not physical growth, of apparently healthy, breast-fed infants in rural communities of northeast Thailand.

    Science.gov (United States)

    Wasantwisut, Emorn; Winichagoon, Pattanee; Chitchumroonchokchai, Chureeporn; Yamborisut, Uruwan; Boonpraderm, Atitada; Pongcharoen, Tippawan; Sranacharoenpong, Kitti; Russameesopaphorn, Wanphen

    2006-09-01

    Iron deficiency is prevalent in children and infants worldwide. Zinc deficiency may be prevalent, but data are lacking. Both iron and zinc deficiency negatively affect growth and psychomotor development. Combined iron and zinc supplementation might be beneficial, but the potential interactions need to be verified. In a randomized, placebo-controlled trial using 2 x 2 factorial design, 609 Thai infants aged 4-6 mo were supplemented daily with 10 mg of iron and/or 10 mg of zinc for 6 mo to investigate effects and interactions on micronutrient status and growth. Iron supplementation alone increased hemoglobin and ferritin concentrations more than iron and zinc combined. Anemia prevalence was significantly lower in infants receiving only iron than in infants receiving iron and zinc combined. Baseline iron deficiency was very low, and iron deficiency anemia was almost nil. After supplementation, prevalence of iron deficiency and iron deficiency anemia were significantly higher in infants receiving placebo and zinc than in those receiving iron or iron and zinc. Serum zinc was higher in infants receiving zinc (16.7 +/- 5.2 micromol/L), iron and zinc (12.1 +/- 3.8 micromol/L) or iron alone (11.5 +/- 2.5 micromol/L) than in the placebo group (9.8 +/- 1.9 micromol/L). Iron and zinc interacted to affect iron and zinc status, but not hemoglobin. Iron supplementation had a small but significant effect on ponderal growth, whereas zinc supplementation did not. To conclude, in Thai infants, iron supplementation improved hemoglobin, iron status, and ponderal growth, whereas zinc supplementation improved zinc status. Overall, for infants, combined iron and zinc supplementation is preferable to iron or zinc supplementation alone.

  11. Neural substrates of semantic memory.

    Science.gov (United States)

    Hart, John; Anand, Raksha; Zoccoli, Sandra; Maguire, Mandy; Gamino, Jacque; Tillman, Gail; King, Richard; Kraut, Michael A

    2007-09-01

    Semantic memory is described as the storage of knowledge, concepts, and information that is common and relatively consistent across individuals (e.g., memory of what is a cup). These memories are stored in multiple sensorimotor modalities and cognitive systems throughout the brain (e.g., how a cup is held and manipulated, the texture of a cup's surface, its shape, its function, that is related to beverages such as coffee, and so on). Our ability to engage in purposeful interactions with our environment is dependent on the ability to understand the meaning and significance of the objects and actions around us that are stored in semantic memory. Theories of the neural basis of the semantic memory of objects have produced sophisticated models that have incorporated to varying degrees the results of cognitive and neural investigations. The models are grouped into those that are (1) cognitive models, where the neural data are used to reveal dissociations in semantic memory after a brain lesion occurs; (2) models that incorporate both cognitive and neuroanatomical information; and (3) models that use cognitive, neuroanatomic, and neurophysiological data. This review highlights the advances and issues that have emerged from these models and points to future directions that provide opportunities to extend these models. The models of object memory generally describe how category and/or feature representations encode for object memory, and the semantic operations engaged in object processing. The incorporation of data derived from multiple modalities of investigation can lead to detailed neural specifications of semantic memory organization. The addition of neurophysiological data can potentially provide further elaboration of models to include semantic neural mechanisms. Future directions should incorporate available and newly developed techniques to better inform the neural underpinning of semantic memory models.

  12. Laser fluorescence spectroscopy of zinc neutrals originating from laser-irradiated and ion-bombarded zinc sulfide and zinc surfaces

    Science.gov (United States)

    Arlinghaus, H. F.; Calaway, W. F.; Young, C. E.; Pellin, M. J.; Gruen, D. M.; Chase, L. L.

    Time-of-flight (TOF) measurements, employing high-resolution laser-induced fluorescence spectroscopy (LFS) as a probe, have been used to measure the yield and velocity distribution of Zn atoms ejected from a ZnS single crystal under irradiation by 308 nm photons. By comparison with the known ion sputtering yield for pure zinc, the absolute yield was determined to be 10 to the 10th power atoms/pulse at a laser fluence of 30 mJ/sq cm. The velocity distribution of the Zn atoms could be fitted by a Maxwell-Boltzmann distribution, having characteristic temperature of approx 2300 K. In addition, Doppler-shift techniques have been combined with TOF measurements in order to separate prompt from delayed emission of ablated atoms, as well as to probe possible molecular or cluster fragmentation. The results obtained suggest the possibility of molecular or cluster emission from ZnS.

  13. Generalization performance of regularized neural network models

    DEFF Research Database (Denmark)

    Larsen, Jan; Hansen, Lars Kai

    1994-01-01

    Architecture optimization is a fundamental problem of neural network modeling. The optimal architecture is defined as the one which minimizes the generalization error. This paper addresses estimation of the generalization performance of regularized, complete neural network models. Regularization...

  14. Opioid Use and Neural Tube Defects

    Science.gov (United States)

    ... CDC.gov . Articles Key Findings: Opioid Use and Neural Tube Defects Recommend on Facebook Tweet Share Compartir The ... relationship to having a pregnancy affected by a neural tube defect (NTD). Researchers from Boston University and CDC ...

  15. Neural overlap in processing music and speech.

    Science.gov (United States)

    Peretz, Isabelle; Vuvan, Dominique; Lagrois, Marie-Élaine; Armony, Jorge L

    2015-03-19

    Neural overlap in processing music and speech, as measured by the co-activation of brain regions in neuroimaging studies, may suggest that parts of the neural circuitries established for language may have been recycled during evolution for musicality, or vice versa that musicality served as a springboard for language emergence. Such a perspective has important implications for several topics of general interest besides evolutionary origins. For instance, neural overlap is an important premise for the possibility of music training to influence language acquisition and literacy. However, neural overlap in processing music and speech does not entail sharing neural circuitries. Neural separability between music and speech may occur in overlapping brain regions. In this paper, we review the evidence and outline the issues faced in interpreting such neural data, and argue that converging evidence from several methodologies is needed before neural overlap is taken as evidence of sharing.

  16. Ocean wave forecasting using recurrent neural networks

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Prabaharan, N.

    , merchant vessel routing, nearshore construction, etc. more efficiently and safely. This paper describes an artificial neural network, namely recurrent neural network with rprop update algorithm and is applied for wave forecasting. Measured ocean waves off...

  17. Application of neural networks in coastal engineering

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.

    the neural network attractive. A neural network is an information processing system modeled on the structure of the dynamic process. It can solve the complex/nonlinear problems quickly once trained by operating on problems using an interconnected number...

  18. Plant Growth Models Using Artificial Neural Networks

    Science.gov (United States)

    Bubenheim, David

    1997-01-01

    In this paper, we descrive our motivation and approach to devloping models and the neural network architecture. Initial use of the artificial neural network for modeling the single plant process of transpiration is presented.

  19. The neural cell adhesion molecule

    DEFF Research Database (Denmark)

    Berezin, V; Bock, E; Poulsen, F M

    2000-01-01

    During the past year, the understanding of the structure and function of neural cell adhesion has advanced considerably. The three-dimensional structures of several of the individual modules of the neural cell adhesion molecule (NCAM) have been determined, as well as the structure of the complex...... between two identical fragments of the NCAM. Also during the past year, a link between homophilic cell adhesion and several signal transduction pathways has been proposed, connecting the event of cell surface adhesion to cellular responses such as neurite outgrowth. Finally, the stimulation of neurite...

  20. Visual Grouping by Neural Oscillators

    CERN Document Server

    Yu, Guoshen

    2008-01-01

    Distributed synchronization is known to occur at several scales in the brain, and has been suggested as playing a key functional role in perceptual grouping. State-of-the-art visual grouping algorithms, however, seem to give comparatively little attention to neural synchronization analogies. Based on the framework of concurrent synchronization of dynamic systems, simple networks of neural oscillators coupled with diffusive connections are proposed to solve visual grouping problems. Multi-layer algorithms and feedback mechanisms are also studied. The same algorithm is shown to achieve promising results on several classical visual grouping problems, including point clustering, contour integration and image segmentation.