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Sample records for b12 absorption based

  1. Vitamin B12 absorption from eggs.

    Science.gov (United States)

    Doscherholmen, A; McMahon, J; Ripley, D

    1975-09-01

    The assimilation of 57Co B12 from in vivo labeled eggs was much inferior to that of a comparable amount of crystalline 57Co B12. Furthermore, the absorption varied with the form in which the eggs were served. Judged by the urinary excretion test and the plasma absorption of radioactivity the average absorption from boiled and fried eggs was more than twice that from scrambled whole eggs, but less than half that absorbed from crystalline 57Co B12.

  2. Vitamin B12 absorption capacity in healthy children

    International Nuclear Information System (INIS)

    Hjelt, K.; Krasilnikoff, P.A.

    1986-01-01

    B12 absorption was investigated in 47 healthy children aged 7 months to 15.8 years (median 4.9 years). The patients had either recovered from giardiasis, the post-gastroenteritis syndrome, or had celiac disease in remission (treated with a gluten-free diet). The B12 absorption was measured by a double-isotope technique using 57 CoB12 and 51 CrCl 3 , the latter being the inabsorbable marker. The radiation dose was minimal. The results were presented as fractional absorption of B12 (FAB12). Within the different age groups, the absorption test was performed by means of the following oral amounts of B12: 0- less than 1 year, 0.5 microgram; 1-3 years: 1.7 micrograms, 4-6 years, 2.5 micrograms; 7-10 years; 3.3 micrograms; and 11-15 years, 4.5 micrograms. When using these oral amounts of B12, the medians (and ranges) of FAB12 were found to be: 1-3 years (n = 18), 37% (16-80%); 4-6 years (n = 10), 27% (19-40%); 7-10 years (n = 9), 32% (21-44%); and 11-15 years (n = 8), 27% (19-59%). The FAB12 in two children aged 7 and 11 months was 31% and 32%, respectively. These results may be interpretated as reference values for B12 absorption in children. Further absorption tests were performed in seven children representing the four age groups from 1 to 15 years. When a high oral amount of B12 was given (i.e., three times the saturation dose), the FAB12 ranged from 0 to 20% (median 9%), whereas a low amount (i.e., one-ninth of the saturation dose) produced fractional absorptions from 65 to 82% (median 74%)

  3. Vitamin B12 absorption capacity in healthy children

    Energy Technology Data Exchange (ETDEWEB)

    Hjelt, K.; Krasilnikoff, P.A.

    1986-03-01

    B12 absorption was investigated in 47 healthy children aged 7 months to 15.8 years (median 4.9 years). The patients had either recovered from giardiasis, the post-gastroenteritis syndrome, or had celiac disease in remission (treated with a gluten-free diet). The B12 absorption was measured by a double-isotope technique using /sup 57/CoB12 and /sup 51/CrCl/sub 3/, the latter being the inabsorbable marker. The radiation dose was minimal. The results were presented as fractional absorption of B12 (FAB12). Within the different age groups, the absorption test was performed by means of the following oral amounts of B12: 0- less than 1 year, 0.5 microgram; 1-3 years: 1.7 micrograms, 4-6 years, 2.5 micrograms; 7-10 years; 3.3 micrograms; and 11-15 years, 4.5 micrograms. When using these oral amounts of B12, the medians (and ranges) of FAB12 were found to be: 1-3 years (n = 18), 37% (16-80%); 4-6 years (n = 10), 27% (19-40%); 7-10 years (n = 9), 32% (21-44%); and 11-15 years (n = 8), 27% (19-59%). The FAB12 in two children aged 7 and 11 months was 31% and 32%, respectively. These results may be interpretated as reference values for B12 absorption in children. Further absorption tests were performed in seven children representing the four age groups from 1 to 15 years. When a high oral amount of B12 was given (i.e., three times the saturation dose), the FAB12 ranged from 0 to 20% (median 9%), whereas a low amount (i.e., one-ninth of the saturation dose) produced fractional absorptions from 65 to 82% (median 74%).

  4. Assay for vitamin B12 absorption and method of making labeled vitamin B12

    Science.gov (United States)

    Anderson, Peter J [Davis, CA; Dueker, Stephen [Davis, CA; Miller, Joshua [Davis, CA; Green, Ralph [Elmacero, CA; Roth, John [Davis, CA; Carkeet, Colleen [Silver Spring, MD; Buchholz,; Bruce, A [Orinda, CA

    2012-06-19

    The invention provides methods for labeling vitamin B12 with .sup.14C, .sup.13C, tritium, and deuterium. When radioisotopes are used, the invention provides for methods of labeling B12 with high specific activity. The invention also provides labeled vitamin B12 compositions made in accordance with the invention.

  5. Holo-transcobalamin is an indicator of vitamin B-12 absorption in healthy adults with adequate vitamin B-12 status

    DEFF Research Database (Denmark)

    von Castel-Roberts, Kristina M; Mørkbak, Anne Louise; Nexo, Ebba

    2007-01-01

    BACKGROUND: It has been hypothesized that the response of holo-transcobalamin (holo-TC) to oral vitamin B-12 may be used to assess absorption. To develop a reliable clinical absorption test that uses holo-TC, it is necessary to determine the optimal timeline for vitamin B-12 administration...... and postdose assessment. OBJECTIVE: The objective of this study was to assess the magnitude and patterns of change in the postabsorption response of holo-TC to oral vitamin B-12. DESIGN: Adult (18-49 y) male and female participants (n = 21) with normal vitamin B-12 status were given three 9-mug doses...... of vitamin B-12 at 6-h intervals beginning early morning (baseline) on day 1. Blood was drawn at 17 timed intervals over the course of 3 d for the analysis of holo-TC and other indicators of vitamin B-12 status. RESULTS: Mean holo-TC increased significantly (P

  6. Absorption of vitamin B12 and effect of pancreatic juice on gastric vitamin B12 binder in the dog

    International Nuclear Information System (INIS)

    Kasaki, Yukio

    1977-01-01

    The effect of pancreatic juice on vitamin B 12 absorption was studied in dogs. It was found that dog gastric juice as well as pancreatic juice contain vitamin B 12 binding proteins which differ in the elution pattern on DEAE-cellulose columns, the former being eluted at much lower sodium chloride concentrations. When radio-active vitamin B 12 was fed or instilled in the proximal bowel and vitamin B 12 recovered at different bowel levels, it was found that vitamin B 12 -protein complex behaved like gastric juice binder in the proximal bowel and like pancreatic binder in the distal. In vitro digestion of gastric binder with pancreatic juice altered vitamin B 12 -protein complex in such a way that elution pattern became similar to that of pancreatic juice. It was also shown that the change was not due to transfer of vitamin B 12 from gastric binder to pancreatic binder. Trypsin digestion had similar effect on gastric binder, and Sephadex G-200 gelfiltration demonstrated reduction in the molecular size. In the doz, vitamin B 12 first bound to gastric binder undergoes chemical changes in the bowel and becomes a readily absorbable form in the distal bowel. (auth.)

  7. Determination of vitamin B12 (cobalamine) absorption by means of a simple double-isotope technique

    International Nuclear Information System (INIS)

    Hippe, E.; Brynskov, J.; Gimsing, P.; Hjelt, K.

    1986-01-01

    The background, practical instruction and clinical results of a simplified method of determining the absorption of cobalamine (vitamin B 12 ) are presented. The simultaneous administration of 57 CO-CN-cobalamine, a non-absorbable marker ( 51 CrCl 3 ), and red carmine tablets enable quantitative assessments of the cobalamine absorption by collection of a small red feaces sample. In contrast to the classical Schilling-test, this vitamin B 12 absorption test (B 12 -ABS-test) or faeces-spot-test is, independent of fasting, flushing dose, renal function and diurnal urinary collection. This is documented in a series of clinical studies. The B 12 -ABS-test provides accurate and precise results compared to the reference method (whole-body-counting). The Schilling test, on the contrary, gives approximately 50% false low values in a reference group of elderly hospitalized patients. A modification of the B 12 -ABS-test, has been used to determine the cobalamine absorption in children, and a set of age-related reference intervals have been established, together with quantitative measurements of the cobalamine absorption in children with small bowel diseases. Based on several years of practical experience, we recommend replacement of the Schilling test by this simple double-isotope technique. (author)

  8. The EGG 57-CO B-12 absorption test, in the evaluation of patients with low serum B-12

    International Nuclear Information System (INIS)

    Sinow, R.M.; Carmel, R.; Siegel, M.E.

    1985-01-01

    The Schilling Test (ST) is the standard test for diagnosing vitamin B-12 malabsorption (MA). However, patients with subtle gastric dysfunction may have normal ST, but impaired absorption of B-12 given with food. The authors have adapted an Egg B-12 Absorption Test (EBAT) in which 57-Co cyanocobalamin (57-Co B-12) is mixed with scrambled egg to evaluate this phenomenon in patients with low serum B-12, normal ST and possible subtle MA. Lyophilized egg yolk is reconstituted and mixed with 57-Co- B-12 of equal dose to that of ST. The authors studied 46 individuals: 13 controls, 5 patients with known pernicious anemia (PA), in addition to 28 patients with low serum B-12 levels and normal ST. ST/EBAT ratios were calculated. Twenty-eight test patients excreted 13.3% on ST and 3.5% on EBAT. Mean ST/EBAT ratio was 8.2 (1.4-35.9). Five had EBAT results in the PA range (<1%) and ST/EBAT ratios (14.4-35.9) that were significantly elevated. This group is also evaluated with pepsinogen I/II ratios, gastric analysis, deoxyuridine suppression tests, anti intrinsic factor, and antiparietal cell antibodies. The authors' results indicate that the EBAT can differentiate between PA and non PA patients, and that some patients with low serum B-12 levels and normal ST may, in fact, have subtle MA. The EBAT, combined with ST/EBAT ratio, may provide a means for identifying this group of patients

  9. Vitamin B 12 absorption: correction of intestinal retention by whole-body profile activity of vitamin B 12-58 cobalt and by double tracer technique

    International Nuclear Information System (INIS)

    Goncalves, M.R. Bencke; Gheldof, R.; Paternot, L. van Tricht; Delmotte, E.; Verschaeren, A.; Martin, P.; Verhas, M.; Universidade Federal, Rio de Janeiro, RJ

    1997-01-01

    Full text. Intestinal retention could give false negative results in determining the whole-body retention of vitamin B 12 absorption (WBC B12-58Co). After having validate the WBC B12-58Co, taking the Schilling test as reference, we have studied the feasibility to evaluate the intestinal contamination by measurement of the profile activity distribution of vitamin B12-58Co and by a double tracer technique (WBC B12-58Co/ WBC 51 Cr Cl3). Methodology: twenty five patients were studied for the setting up of the new methodology. For eleven of them the WBC B12-58 Co retention was measured at the 7th day after the oral administration of 37KBq of B12-58Co using a four detectors whole body counter. One week later, a Schilling test was performed after the oral absorption of 18,5 KBq B12-57Co. Results were expressed as %ID. In these patients, one single peak of hepatic activity was observed on the whole body profile and thus no further intestinal correction was needed. In order to evaluate the intestinal contribution, we made in nine other patients the profile of the whole body distribution of activity at 1 h, 1 week and two weeks after the oral administration of B12-58Co. For five other patients a double tracer technique was used for intestinal correction after the simultaneous oral administration of 37 KBq of B12-58Co and 1,85 MBq of 51 Cr Cl3. The B12-58Co absorption was evaluated after intestinal correction based on subtraction of the 51Cr Cl3 contribution after the formula: B12-58Co(%ID) = WBC B12-58Co - WBC 51 Cr Cl3/1 - WBC 51 Cr Cl3. Results: the correlation with the Schilling test was found excellent: r=0,94 (n=11). The normality for WBC retention (n=7) was define as 53,2 +-12,4% ID (SD). For nine patients studied at the 7th day, the presence of a double peak (hepatic and intestinal peaks) allowed the subtraction by exponential extrapolation; the correction range was 4,4% to 37,2%. With the exception of one observation there was no difference in the measure of vitamin

  10. Vitamin B12 absorption judged by measurement of holotranscobalamin, active vitamin B12: evaluation of a commercially available EIA kit.

    Science.gov (United States)

    Greibe, Eva; Nexo, Ebba

    2011-11-01

    Active vitamin B12 absorption is followed by an increase in holotranscobalamin (holoTC) upon loading with a high physiological dose of the vitamin (the CobaSorb test). This study evaluates the use of a newly launched EIA kit for measurement of holoTC (active B12) in relation to the CobaSorb test. Intra-assay imprecision and linearity of the EIA kit was examined, employing serum pools of increasing holoTC concentrations. For the CobaSorb test, holoTC was measured before and after loading with 3-times 9 μg of vitamin B12 employing both the in-house ELISA and the EIA kit (n=25). The EIA kit showed an intra-assay CV between 2.2% and 5.8% for holoTC values ranging from 21 to 80 pmol/L. Employing diluted serum samples resulted in spurious high values of holoTC. The EIA kit performed well in relation to the CobaSorb test and classified the patients studied as capable of absorbing vitamin B12 (n=10) or not (n=15), as did the in-house ELISA. The Active B12 (holoTC) EIA kit proved suitable for use with the CobaSorb test, but not for analysis of diluted serum samples.

  11. Absorption and transport of radioactive 57Co-vitamin B12 in experimental giardiasis in rats

    International Nuclear Information System (INIS)

    Deka, N.C.; Sehgal, A.K.; Chnuttani, P.N.

    1981-01-01

    Giardiasis was produced in weanling albino rats by feeding suspension of Giardia lamblia cysts isolated from human stool. Experiments were carried out to assess the absorption and transport through intestinal wall of 57 Co-vitamin B 12 in these rats. The results showed a significant impairment of the absorption of the vitamin in the rats with experimental giardiasis. However, the transport of the vitamin B 12 was unimpaired. (author)

  12. Intestinal synthesis and absorption of vitamin B-12 in channel catfish

    International Nuclear Information System (INIS)

    Limsuwan, T.; Lovell, R.T.

    1981-01-01

    A feeding experiment conducted in a controlled environment and using a vitamin B12-deficient, but otherwise nutritionally complete, purified diet revealed that intestinal microorganisms in channel catfish synthesized approximately 1.4 ng of vitamin B12 per gram of bodyweight per day. Removal of cobalt from the diet or supplementation with an antibiotic (succinylsulfathiazole) significantly reduced the rate of intestinal synthesis and liver stores of vitamin B12. Radiolabeled vitamin B12 in the blood, liver, kidneys, and spleen of fish fed 60Co in the diet indicated that the intestinally synthesized vitamin was absorbed by the fish. The primary route of absorption was directly from the digestive tract into the blood because coprophagy was prevented in the rearing aquariums and the amount of vitamin B12 dissolved in the aquarium water was too low for gill absorption. Dietary supplementation of vitamin B12 was not necessary for normal growth and erythrocyte formation in channel catfish in a 24-week feeding period. A longer period, however, may have caused a vitamin deficiency since liver-stored vitamin B 12 decreased between the 2nd and 24th weeks

  13. Dual isotope Schilling test for measuring absorption of food-bound and free vitamin B12 simultaneously

    International Nuclear Information System (INIS)

    Doscherholmen, A.; Silvis, S.; McMahon, J.

    1983-01-01

    A prototype food-bound vitamin B12 (food-B12) absorption test has been developed in which 57 Co-B12 was incorporated in vitro into egg yolk (yolk-B12) and served to volunteers in 50-g cooked portions together with toast and coffee for breakfast. Six hours later, 1 mg nonlabeled B12 was given intramuscularly and 24-hour urine was collected for radioactivity measurement. In separate tests, the absorption of yolk-B12 and crystalline 57 Co-B12 was equally poor in patients with pernicious anemia. However, in patients with simple gastric achlorhydria and those who had undergone gastric surgery, the assimilation of yolk-B12 was impaired greatly, whereas the absorption of crystalline radio-B12 was normal. Egg yolk labeled with 58 Co-B12 was administered together with crystalline 57 Co-B12 in a dual isotope test with results similar to those obtained when the tests were prepared separately. This yolk- 58 Co-B12 test with its ability to detect malabsorption of food-B12 may be considered as an addition to the first part of the Schilling test

  14. Measurement of total-body cobalt-57 vitamin B12 absorption with a gamma camera

    International Nuclear Information System (INIS)

    Cardarelli, J.A.; Slingerland, D.W.; Burrows, B.A.; Miller, A.

    1985-01-01

    Previously described techniques for the measurement of the absorption of [ 57 Co]vitamin B 12 by total-body counting have required an iron room equipped with scanning or multiple detectors. The present study uses simplifying modifications which make the technique more available and include the use of static geometry, the measurement of body thickness to correct for attenuation, a simple formula to convert the capsule-in-air count to a 100% absorption count, and finally the use of an adequately shielded gamma camera obviating the need of an iron room

  15. A review of radioisotope techniques in the study of vitamin B12 absorption

    International Nuclear Information System (INIS)

    Boddy, K.

    1976-01-01

    The five in vivo tests in common use for the study of vitamin B 12 absorption, namely, 1) faecal excretion method, 2) urinary excretion method, 3) plasma radioactivity method, 4) hepatic uptake method, and 5) whole-body counting method, are described. The merits, disadvantages and limitations of each method are considered in a clinical context. Whole-body counting is regarded as the method of choice where appropriate facilities are available and when the delay of about 7 days in obtaining the result is acceptable. The plasma radioactivity method can provide concurrently a rapid assessment. (author)

  16. Human Vitamin B12 Absorption and Metabolism are Measured by Accelerator Mass Spectrometry Using Specifically Labeled 14C-Cobalamin

    International Nuclear Information System (INIS)

    Carkeet, C; Dueker, S R; Lango, J; Buchholz, B A; Miller, J W; Green, R; Hammock, B D; Roth, J R; Anderson, P J

    2006-01-01

    There is need for an improved test of human ability to assimilate dietary vitamin B 12 . Assaying and understanding absorption and uptake of B 12 is important because defects can lead to hematological and neurological complications. Accelerator mass spectrometry (AMS) is uniquely suited for assessing absorption and kinetics of 14 C-labeled substances after oral ingestion because it is more sensitive than decay counting and can measure levels of carbon-14 ( 14 C) in microliter volumes of biological samples, with negligible exposure of subjects to radioactivity. The test we describe employs amounts of B 12 in the range of normal dietary intake. The B 12 used was quantitatively labeled with 14 C at one particular atom of the DMB moiety by exploiting idiosyncrasies of Salmonellametabolism. In order to grow aerobically on ethanolamine, S. entericamust be provided with either pre-formed B 12 or two of its precursors: cobinamide and dimethylbenzimidazole (DMB). When provided with 14 C-DMB specifically labeled in the C2 position, cells produced 14 C-B 12 of high specific activity (2.1 GBq/mmol, 58 mCi/mmol) and no detectable dilution of label from endogenous DMB synthesis. In a human kinetic study, a physiological dose (1.5 mg, 2.2 KBq/59 nCi) of purified 14 C-B 12 was administered and showed plasma appearance and clearance curves consistent with the predicted behavior of the pure vitamin. This method opens new avenues for study of B 12 assimilation

  17. 59Fe and 58Co-vitamin B12 absorptions studies in radiotherapy of collum carcinomas by whole-body radiometry

    International Nuclear Information System (INIS)

    Kaplan, M.A.; Bolovin, L.M.; Verkhovskaya, N.I.; Mel'nikova, L.N.; Yavor, T.; Bero, T.

    1983-01-01

    The results of examination of iron and vitamin B-12 metabolism in the radiotherapy of collum carcinomas are reported. The absorption of iron and vitamin B-12 was found to decrease under the influence of radiotherapy. The degree of the absorption decrease depends on the radiation dose. (author)

  18. Fluorescent carbon dots nanosensor for label-free determination of vitamin B12 based on inner filter effect

    Science.gov (United States)

    Ding, Longhua; Yang, Hongmei; Ge, Shenguang; Yu, Jinghua

    2018-03-01

    A simple and effective fluorescent assay for the determination of vitamin B12 was developed. In this study, carbon dots (CDs) were prepared by one-pot hydrothermal method and directly used as a fluorophore in the inner filter effect (IFE). Both of the maximum absorption peak of vitamin B12 and excitation maxima of CDs are located at 360 nm, hence, the excited light of CDs can be absorbed by vitamin B12, resulting in the fluorescence reduction of CDs. And the fluorescence intensity of CDs decreases with the increasing concentration of vitamin B12. This IFE-based sensing strategy shows a good linear relationship between the normalized fluorescence intensity and the concentration of vitamin B12 ranging from 0 to 60 μM, with a limit of detection (LOD) of 0.1 μM at a signal-to-noise ratio of 3. Furthermore, this proposed approach was successfully applied to vitamin B12 sensing in injections. This IFE sensing platform based on various fluorescent nanomaterials has a high promise for the detection of other biomolecules due to its inherent convenience.

  19. Route and Type of Formulation Administered Influences the Absorption and Disposition of Vitamin B12 Levels in Serum

    Directory of Open Access Journals (Sweden)

    Luis Vitetta

    2018-01-01

    Full Text Available The administration of biological compounds that optimize health benefits is an ever-evolving therapeutic goal. Pharmaceutical and other adjunctive biological compounds have been administered via many different routes in order to produce a systemic pharmacological effect. The article summarizes the findings from an Australian comparative study in adults administered vitamin B12 through different oral delivery platforms. A total of 16 subjects (9 males, 7 females voluntarily partook in a comparative clinical study of five different vitamin B12 formulations across a six-month period, completing 474 person-hours of cumulative contribution, that was equivalent to an n = 60 participation. A nanoparticle delivered vitamin B12 through a NanoCelle platform was observed to be significantly (p < 0.05 better absorbed than all other dose equivalent platforms (i.e., tablets, emulsions, or liposomes from baseline to 1, 3, and 6 h of the study period. The nanoparticle platform delivered vitamin B12 demonstrated an enhanced and significant absorption profile as exemplified by rapid systemic detection (i.e., 1 h from baseline when administered to the oro-buccal mucosa with no reports of any adverse events of toxicity. The nanoparticle formulation of methylcobalamin (1000 µg/dose in 0.3 mL volume showed bioequivalence only with a chewable-dissolvable tablet that administered a five times higher dose of methylcobalamin (5000 µg per tablet. This study has demonstrated that an active metabolite embedded in a functional biomaterial (NanoCelle may constitute a drug delivery method that can better access the circulatory system.

  20. Validity of transcobalamin II-based radioassay for the determination of serum vitamin B12 concentrations

    International Nuclear Information System (INIS)

    Paltridge, G.; Rudzki, Z.; Ryall, R.G.

    1980-01-01

    A valid radioassay for the estimation of serum vitamin B 12 in the presence of naturally occurring vitamin B 12 (= cobalamin) analogues can be operated if serum transcobalamin II (TC II) is used as the binding protein. Serum samples that gave diagnostically discrepant results when their vitamin B 12 content was analysed (i) by a commercial radioassay known to be susceptible to interference from cobalamin analogues, and (ii) by microbiological assay, were further analysed by an alternative radioassay which uses the transcobalamins (principally TC II) of diluted normal serum as the assay binding protein. Concordance between the results from microbiological assay and the TC II-based radioassay was found in all cases. In an extended study over a three-year period, all routine serum samples sent for vitamin B 12 analysis that had a vitamin B 12 content of less than 320 ng/l by the TC II-based radioassay (reference range 200-850 ng/l) were reanalysed using an established microbiological method. Over 1000 samples were thus analysed. The data are presented to demonstrate the validity of the TC II-based radioassay results in this group of patients, serum samples from which are most likely to produce diagnostically erroneous vitamin B 12 results when analysed by a radioassay that is less specific for cobalamins. (author)

  1. Electronically excited states of vitamin B12 and methylcobalamin: theoretical analysis of absorption, CD, and MCD data.

    Science.gov (United States)

    Solheim, Harald; Kornobis, Karina; Ruud, Kenneth; Kozlowski, Pawel M

    2011-02-03

    Linear and quadratic response time-dependent density functional theory (TD-DFT) has been applied to investigate absorption (Abs), circular dichroism (CD), and magnetic CD (MCD) spectra of cyanocobalamin (CNCbl) and methylcobalamin (MeCbl). Although electronically excited states of both cobalamins have been probed by applying different experimental techniques, their exact nature remains poorly understood from an electronic structure point of view. Recent theoretical studies have revealed a lot of relevant information about their properties but also left some unresolved issues related to the nature of individual transitions. In this contribution, not only Abs but also CD and MCD spectra of both cobalamins were computed for direct comparison with experiment. The results were evaluated with respect to the choice of exchange-correlation functional, basis set, and the environment (gas phase or solvent) used in the calculation. Taking into account the complexity of the CNCbl and MeCbl systems, reliable agreement between theory and experiment was achieved based on calculations employing the BP86 functional, particularly for the low-energy α/β bands. This spectral range has been traditionally interpreted as a vibrational progression associated with a single electronic excitation, but according to the present analysis for both cobalamins, these bands are best interpreted as consisting of multiple electronic transitions.

  2. Dipstick based immunochemiluminescence biosensor for the analysis of vitamin B12 in energy drinks: A novel approach

    International Nuclear Information System (INIS)

    Selvakumar, L.S.; Thakur, M.S.

    2012-01-01

    Graphical abstract: (a) Schematic representation of immunochemiluminescence based dipstick technique for detection of vitamin B 12 . (b) Enzymatic dephosphorylation of dioxetane by alkaline phosphatase. Highlights: ► Dipstick based immunochemiluminescence biosensor proposed for vitamin B 12 analysis. ► The limit of detection of vitamin B 12 is 1 ng mL −1 and applied in energy drinks. ► Chemiluminescence generated was inversely proportional to vitamin B 12 concentration. ► Chemiluminescence analytical procedure was compared with ELISA. ► Alkaline phosphatase was stable chemiluminescent enzyme than Horse Radish Peroxidase. - Abstract: In this article, we describe a dipstick based immunochemiluminescence (immuno-CL) biosensor for the detection of vitamin B 12 in energy drinks. The method is a direct competitive type format involving the immobilization of vitamin B 12 antibody on nitrocellulose membrane (NC) followed by treatment with vitamin B 12 and vitamin B 12 –alkaline phosphatase conjugate to facilitate the competitive binding. The dipstick was further treated with substrate disodium 2-chloro-5-(4-methoxyspiro {1,2-dioxetane-3,2¢-(5¢-chloro)tricyclo[3.3.1.13,7]decan}-4-yl)-1-phenyl phosphate (CDP-Star) to generate chemiluminescence (CL). The number of photons generated was inversely proportional to the vitamin B 12 concentration. After systematic optimization, the limit of detection was 1 ng mL −1 . The coefficient of variation was below 0.2% for both intra- and inter-assay precision. Vitamin B 12 was extracted from energy drinks with recovery ranged from 90 to 99.4%. Two different energy drinks samples were analyzed, and a good correlation was observed when the data were compared with a reference enzyme linked immuno sorbent assay (ELISA) method. The developed method is suitable for an accurate, sensitive, and high-throughput screening of vitamin B 12 in energy drinks samples. The dipstick technique based on immuno-CL is suitable for the

  3. Fasting time and vitamin B12 levels in a community-based population.

    Science.gov (United States)

    Orton, Dennis J; Naugler, Christopher; Sadrzadeh, S M Hossein

    2016-07-01

    Vitamin B12, also known as cobalamin (Cbl), is an essential vitamin that manifests with numerous severe but non-specific symptoms in cases of deficiency. Assessing Cbl status often requires fasting, although this requirement is not standard between institutions. This study evaluated the impact of fasting on Cbl levels in a large community-based cohort in an effort to promote standardization of Cbl testing between sites. Laboratory data for Cbl, fasting time, patient age and sex were obtained from laboratory information service from Calgary Laboratory Services (CLS) for the period of April 2011 to June 2015. CLS is the sole supplier of laboratory services in the Southern Alberta region in Canada (population, approximately 1.4 million). To investigate potential sex-specific effects of fasting on Cbl levels, males and females were analyzed separately using linear regression models. A total of 346,957 individual patient results (196,849 females, 146,085 males) were obtained. The mean plasma Cbl level was 386.5 (±195.6) pmol/L and 412.0 (±220.8) pmol/L for males and females, respectively. Linear regression analysis showed fasting had no significant association with Cbl levels in females; however a statistically significant decrease of 0.9pmol/L/hour fasting (pfasting has the potential to contribute to higher rates of Cbl deficiency in men. Together, these data suggest fasting should be excluded as a requirement for evaluating plasma Cbl. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Distinct intestinal adaptation for vitamin B12 and bile acid absorption revealed in a new mouse model of massive ileocecal resection.

    Science.gov (United States)

    Matsumoto, Yuka; Mochizuki, Wakana; Akiyama, Shintaro; Matsumoto, Taichi; Nozaki, Kengo; Watanabe, Mamoru; Nakamura, Tetsuya

    2017-09-15

    Ileocecal resection (ICR), one of several types of intestinal resection that results in short bowel syndrome (SBS), causes severe clinical disease in humans. We here describe a mouse model of massive ICR in which 75% of the distal small intestine is removed. We demonstrate that mice underwent 75% ICR show severe clinical signs and high mortality, which may recapitulate severe forms of human SBS, despite an adaptive response throughout the remnant intestine. By using this model, we also investigated whether the epithelium of the remnant intestine shows enhanced expression of factors involved in region-specific functions of the ileum. Cubn mRNA and its protein product, which play an essential role in vitamin B12 absorption in the ileum, are not compensatory up-regulated in any part of the remnant intestine, demonstrating a clear contrast with post-operative up-regulation of genes involved in bile acid absorption. Our study suggests that functional adaptation by phenotypical changes in the intestinal epithelium is not a general feature for nutrient absorption systems that are confined to the ileum. We also propose that the mouse model developed in this study will become a unique system to facilitate studies on SBS with ICR in humans. © 2017. Published by The Company of Biologists Ltd.

  5. Distinct intestinal adaptation for vitamin B12 and bile acid absorption revealed in a new mouse model of massive ileocecal resection

    Directory of Open Access Journals (Sweden)

    Yuka Matsumoto

    2017-09-01

    Full Text Available Ileocecal resection (ICR, one of several types of intestinal resection that results in short bowel syndrome (SBS, causes severe clinical disease in humans. We here describe a mouse model of massive ICR in which 75% of the distal small intestine is removed. We demonstrate that mice underwent 75% ICR show severe clinical signs and high mortality, which may recapitulate severe forms of human SBS, despite an adaptive response throughout the remnant intestine. By using this model, we also investigated whether the epithelium of the remnant intestine shows enhanced expression of factors involved in region-specific functions of the ileum. Cubn mRNA and its protein product, which play an essential role in vitamin B12 absorption in the ileum, are not compensatory up-regulated in any part of the remnant intestine, demonstrating a clear contrast with post-operative up-regulation of genes involved in bile acid absorption. Our study suggests that functional adaptation by phenotypical changes in the intestinal epithelium is not a general feature for nutrient absorption systems that are confined to the ileum. We also propose that the mouse model developed in this study will become a unique system to facilitate studies on SBS with ICR in humans.

  6. Elevated plasma vitamin B12 levels and risk of venous thromboembolism among cancer patients: A population-based cohort study

    DEFF Research Database (Denmark)

    Arendt, Johan Frederik Håkonsen; Farkas, Dora Kormendine; Pedersen, Lars

    2017-01-01

    INTRODUCTION: Both venous thromboembolism (VTE) and high plasma vitamin B12 levels (cobalamin, Cbl) are markers of occult cancer and aggressive cancer with a poor prognosis. In this population-based cohort study, we assessed VTE risk among cancer patients with high plasma Cbl levels. MATERIALS...

  7. Vitamin B12

    Science.gov (United States)

    ... Consumer Datos en español Health Professional Other Resources Vitamin B12 Fact Sheet for Consumers Have a question? ... out more about vitamin B12? Disclaimer What is vitamin B12 and what does it do? Vitamin B12 ...

  8. EVIDENCE-BASED DATA ON EFFECTIVENESS OF LACTOBACILLUS RHAMNOSUS GG AND BIFIDOBACTERIUM LACTIS ВB-12 IN PEDIATRIC PRACTICE

    Directory of Open Access Journals (Sweden)

    I. V. Andreyeva

    2011-01-01

    Full Text Available Prophylactic and therapeutic administration of prebiotics in treatment of different disorders is used very often nowadays. However, this kind of a treatment confirmed its efficacy in only several diseases. The review presents the data on efficacy of two probiotic microorganisms (L. rhamnosus GG and B. lactis Вb-12 in pediatric practice. Author summarizes and analyzes existing evidence-based data on efficacy of probiotics in treatment of acute diarrhea, prophylaxis of antibiotic-associated diarrhea and nosocomial infections. L. rhamnosus GG and B. lactis Вb-12 have their own place in prophylaxis of infections of airways and gastrointestinal tract. Administration of probiotics for treatment and prophylaxis of allergic and other diseases is reviewed. Safety of probiotics is described as well.

  9. Vitamin B12 deficiency

    Science.gov (United States)

    Vitamin B12 (B12; also known as cobalamin) is a B vitamin that has an important role in cellular metabolism, especially in DNA synthesis, methylation and mitochondrial metabolism. Clinical B12 deficiency with classic haematological and neurological manifestations is relatively uncommon. However, sub...

  10. Functional soy food based on flaxseed and quinoa and enriched with iron and Vitamin B12

    Directory of Open Access Journals (Sweden)

    Ana Carolina Braga

    2015-07-01

    Full Text Available A diet rich in food derived from vegetables reduces the risk of developing chronic and degenerative diseases and provides the essential nutrients for human consumption. Besides soybean, other foods of vegetal origin have been studied and incorporated in healthy formulations, such as quinoa and linseed. Current assay comprises a sensorial analysis of a product of vegetable origin, a soy product, based on quinoa and flaxseed, considered to be functional food, for its organoleptic characteristics acceptable by a sample group of 80 individuals. Several tests were conducted to reach an adequate formulation for the product, characterized by 11.1 g of protein content, 9.6 g of dietary fiber and low levels of lipids, since it had only 1.4 g. The resulting product revealed adequate microbiological conditions when subjected to microbiological analysis (coliforms at 45ºC; coliforms at 35ºC and Staphylococcus aureus. According to scores in the sensory analysis, it may be assumed that the product was accepted by the sample group. The favorable results indicate the possibility of consumers adhering to a processed diet rich in food derived from vegetables, with functional properties, to replace animal-derived food which is rich in saturated fats and low in fiber.

  11. Vitamin B-12

    Science.gov (United States)

    Vitamin B-12 is a cofactor for 2 enzymes. In the cytoplasm, methionine synthase requires vitamin B-12 in the form of methylcobalamin and catalyzes the conversion of homocysteine to methionine by transfer of a methyl group from methyltetrahydrofolate.This enzyme links the methylation pathway through ...

  12. Vitamin B12 deficiency

    DEFF Research Database (Denmark)

    Green, Ralph; Allen, Lindsay H; Bjørke-Monsen, Anne-Lise

    2017-01-01

    , subclinical deficiency affects between 2.5% and 26% of the general population depending on the definition used, although the clinical relevance is unclear. B12 deficiency can affect individuals at all ages, but most particularly elderly individuals. Infants, children, adolescents and women of reproductive age...... remain debated. Management depends on B12 supplementation, either via high-dose oral routes or via parenteral administration. This Primer describes the current knowledge surrounding B12 deficiency, and highlights improvements in diagnostic methods as well as shifting concepts about the prevalence, causes...

  13. Vitamin B12

    Science.gov (United States)

    Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. National Academies Press. Washington, DC, 1998. PMID: 23193625 ...

  14. Applications of the Schilling test and saturation analysis techniques to the investigation of absorption and transport of vitamin B-12 in Ugandans. Part of a coordinated programme on in vitro assay techniques

    International Nuclear Information System (INIS)

    Kajubi, S.K.; Okel, R.M.

    1975-11-01

    The absorption of Vitamin B12 in 21 subjects was investigated, using the Schilling test. One microgramme of radioactive Vitamin B12 followed by a flushing dose of 1000 mcg after 2 hours resulted in very low urinary excrection rates. Different flushing doses were administered to 11 asymptomatic volunteers at different times after the active dose. Adequate excretion was obtained when a flushing dose of 5000 mcg of B12 was given five hours after the active dose. In 23 other subjects this combination was found to give excretion rates comparable to those found in other populations where the usual procedure had been used. Plasma and urine patterns of radioactivity showed that, when the standard method was used, there was no failure of vitamin absorption but flushing from the plasma was poor. Flushing was more effective with the modified procedure. An additional binder in the plasma of Ugandans is likely; its effect may have combined with the previously demonstrated slow rate of absorption of vitamin to make the modified method effective and the standard one ineffective. A new procedure for the Schilling test is therefore proposed for this population since the standard method would be unsuitable

  15. Malabsorption of protein bound vitamin B12.

    OpenAIRE

    Dawson, D W; Sawers, A H; Sharma, R K

    1984-01-01

    Patients with subnormal serum vitamin B12 concentrations were tested for absorption of protein bound vitamin B12 and compared with controls. Absorption of the protein bound vitamin appeared to decrease with increasing age in healthy subjects. Differences between the result of this test and the result of the Schilling test in patients who had undergone gastric surgery were confirmed; such differences were also seen in some patients who had iron deficiency anaemia, an excessive alcohol intake, ...

  16. Amnionless function is required for cubilin brush-border expression and intrinsic factor-cobalamin (vitamin B12) absorption in vivo

    Science.gov (United States)

    He, Qianchuan; Madsen, Mette; Kilkenney, Adam; Gregory, Brittany; Christensen, Erik I.; Vorum, Henrik; Højrup, Peter; Schäffer, Alejandro A.; Kirkness, Ewen F.; Tanner, Stephan M.; de la Chapelle, Albert; Giger, Urs; Moestrup, Søren K.; Fyfe, John C.

    2005-01-01

    Amnionless (AMN) and cubilin gene products appear to be essential functional subunits of an endocytic receptor called cubam. Mutation of either gene causes autosomal recessive Imerslund-Gräsbeck syndrome (I-GS, OMIM no. 261100) in humans, a disorder characterized by selective intestinal malabsorption of cobalamin (vitamin B12) and urinary loss of several specific low-molecular-weight proteins. Vital insight into the molecular pathology of I-GS has been obtained from studies of dogs with a similar syndrome. In this work, we show that I-GS segregates in a large canine kindred due to an in-frame deletion of 33 nucleotides in exon 10 of AMN. In a second, unrelated I-GS kindred, affected dogs exhibit a homozygous substitution in the AMN translation initiation codon. Studies in vivo demonstrated that both mutations abrogate AMN expression and block cubilin processing and targeting to the apical membrane. The essential features of AMN dysfunction observed in vivo are recapitulated in a heterologous cell-transfection system, thus validating the system for analysis of AMN-cubilin interactions. Characterization of canine AMN mutations that cause I-GS establishes the canine model as an ortholog of the human disorder well suited to studies of AMN function and coevolution with cubilin. (Blood. 2005;106:1447-1453) PMID:15845892

  17. Metabolic distress in lipid & one carbon metabolic pathway through low vitamin B-12: a population based study from North India.

    Science.gov (United States)

    Saraswathy, Kallur Nava; Joshi, Shipra; Yadav, Suniti; Garg, Priyanka Rani

    2018-04-25

    Dyslipidemia and hyper-homocysteinemia are the major independent risk factors of cardio vascular disease. Deficiency of folate and vitamin B-12 are associated with both hyper-homocysteinemia and dyslipidemia. The aim of the study is to evaluate the relationship of homocysteine and its associated dietary determinant levels (Folate and Vitamin B-12) with lipids and obesity parameters (WC, BMI, WHR) in North Indian population. The participants were recruited under a major government funded project through household survey covering 15 villages of Haryana, India. Participants were both males and females, between age group 30-65 years, from a north Indian community. Initially 1634 individuals were recruited, of which 1374 were considered for analysis as they were not found to be on any kind of medication for high blood pressure, CAD, diabetes or any other disorder, and had no missing data. 5 mL of intravenous blood sample was collected after obtaining written informed consent from the participants. Homocysteine, folate and vitamin B12 levels were estimated through Immulite 1000 by chemi-luminescence technique. Triglyceride, total cholesterol and HDL-C were estimated by spectrophotometry technique using commercial kits. The values for LDL and VLDL were calculated using Friedwald's equation. Height, weight, waist circumference (WC), hip circumference (HC) was measured over light clothing. Statistical analysis for data was performed using SPSS 16.0 version. All the lipid indices, except HDL, showed a trend of negative correlation with homocysteine after controlling for confounders, though not significant. No association was found between obesity (WC, BMI, WHR) and homocysteine in the present study. Vitamin B-12 deficiency was significantly associated with both hyper-homocysteinemia and low HDL. Folate was found to have significantly reduced risk for high TC & LDL. The "hcy-lipid" hypothesis does not seem to be complementing in the present studied population. The

  18. Radioactively labelled vitamin B12

    International Nuclear Information System (INIS)

    Charlton, J.C.; Hamilton, A.L.

    1978-01-01

    The application concerns the manufacture of radioactive forms of vitamin B-12 in which the cobalt atom present in the vitamin B-12 molecule is replaced with a radioactive isotope of cobalt, usually cobalt-57 or cobalt-58. Such radioactive forms of B-12 are used extensively in the diagnosis of B-12 deficiency states

  19. Organometallic B12-DNA conjugate

    DEFF Research Database (Denmark)

    Hunger, Miriam; Mutti, Elena; Rieder, Alexander

    2014-01-01

    Design, synthesis, and structural characterization of a B12-octadecanucleotide are presented herein, a new organometallic B12-DNA conjugate. In such covalent conjugates, the natural B12 moiety may be a versatile vector for controlled in vivo delivery of oligonucleotides to cellular targets in hum...

  20. Architecture for Absorption Based Heaters

    Science.gov (United States)

    Moghaddam, Saeed; Chugh, Devesh

    2018-04-24

    An absorption based heater is constructed on a fluid barrier heat exchanging plate such that it requires little space in a structure. The absorption based heater has a desorber, heat exchanger, and absorber sequentially placed on the fluid barrier heat exchanging plate. The vapor exchange faces of the desorber and the absorber are covered by a vapor permeable membrane that is permeable to a refrigerant vapor but impermeable to an absorbent. A process fluid flows on the side of the fluid barrier heat exchanging plate opposite the vapor exchange face through the absorber and subsequently through the heat exchanger. The absorption based heater can include a second plate with a condenser situated parallel to the fluid barrier heat exchanging plate and opposing the desorber for condensation of the refrigerant for additional heating of the process fluid.

  1. Contribution of meat to vitamin B-12, iron, and zinc intakes in five ethnic groups in the U.S.: Implications for developing food-based dietary guidelines

    Science.gov (United States)

    Sharma, Sangita; Sheehy, Tony; Kolonel, Laurence N

    2016-01-01

    Background To describe the sources of meat and their contributions to vitamin B-12, iron, and zinc in five ethnic groups in the USA. Methods Dietary data for the Multiethnic Cohort, established in Hawaii and Los Angeles, were collected using a quantitative food frequency questionnaire from more than 215,000 subjects aged 45–75 years at baseline (1993–1996). Participants included African American, Latino, Japanese American (JpAm), Native Hawaiian (NH) and Caucasian men and women. Servings of meat items were calculated based on the USDA recommendations and their contributions to intakes of total meat, red meat, vitamin B-12, iron, and zinc were determined. Results Of all types of meat, poultry contributed the most to meat consumption, followed by red meat and fish among all ethnicities, except for Latino (born in Mexico and Central/South America) men who consumed more beef. Lean beef was the most commonly consumed red meat for all ethnic-sex groups (9.3–14.3%), except for NH and JpAm men, and JpAm women whose top contributor was stew/curry with beef/lamb and stir-fried beef/pork with vegetables respectively. The contribution of meat was most substantial for zinc (11.1–29.3%) and vitamin B-12 (19.7–40%), and to a lesser extent for iron (4.3–14.2%). Conclusions This is the first large multiethnic cohort study to describe meat sources and their contributions to selected nutrients among ethnic minorities in the U.S. These findings may be used to develop ethnic-specific recommendations for meat consumption to improve dietary quality among these groups. PMID:23398393

  2. WE-DE-207B-12: Scatter Correction for Dedicated Cone Beam Breast CT Based On a Forward Projection Model

    Energy Technology Data Exchange (ETDEWEB)

    Shi, L; Zhu, L [Georgia Institute of Technology, Atlanta, GA (Georgia); Vedantham, S; Karellas, A [University of Massachusetts Medical School, Worcester, MA (United States)

    2016-06-15

    Purpose: The image quality of dedicated cone-beam breast CT (CBBCT) is fundamentally limited by substantial x-ray scatter contamination, resulting in cupping artifacts and contrast-loss in reconstructed images. Such effects obscure the visibility of soft-tissue lesions and calcifications, which hinders breast cancer detection and diagnosis. In this work, we propose to suppress x-ray scatter in CBBCT images using a deterministic forward projection model. Method: We first use the 1st-pass FDK-reconstructed CBBCT images to segment fibroglandular and adipose tissue. Attenuation coefficients are assigned to the two tissues based on the x-ray spectrum used for imaging acquisition, and is forward projected to simulate scatter-free primary projections. We estimate the scatter by subtracting the simulated primary projection from the measured projection, and then the resultant scatter map is further refined by a Fourier-domain fitting algorithm after discarding untrusted scatter information. The final scatter estimate is subtracted from the measured projection for effective scatter correction. In our implementation, the proposed scatter correction takes 0.5 seconds for each projection. The method was evaluated using the overall image spatial non-uniformity (SNU) metric and the contrast-to-noise ratio (CNR) with 5 clinical datasets of BI-RADS 4/5 subjects. Results: For the 5 clinical datasets, our method reduced the SNU from 7.79% to 1.68% in coronal view and from 6.71% to 3.20% in sagittal view. The average CNR is improved by a factor of 1.38 in coronal view and 1.26 in sagittal view. Conclusion: The proposed scatter correction approach requires no additional scans or prior images and uses a deterministic model for efficient calculation. Evaluation with clinical datasets demonstrates the feasibility and stability of the method. These features are attractive for clinical CBBCT and make our method distinct from other approaches. Supported partly by NIH R21EB019597, R21CA134128

  3. Vitamin B12 deficiency anemia

    Science.gov (United States)

    ... diet Poor diet in infants Poor nutrition during pregnancy Certain health conditions can make it difficult for your body to absorb enough vitamin B12. They include: Chronic alcoholism Crohn disease, celiac disease, infection with the fish ...

  4. Assay of vitamin B12

    International Nuclear Information System (INIS)

    Tovey, K.C.; Carrick, D.T.

    1982-01-01

    A radioassay is described for vitamin B12 which involves denaturing serum protein binding proteins with alkali. In the denaturation step a dithiopolyol and cyanide are used and in the intrinsic factor assay step a vitamin B12 analogue such as cobinamide is used to bind with any remaining serum proteins. The invention also includes a kit in which the dithiopolyol is provided in admixture with the alkali. The dithiopolyol may be dithiothreitol or dithioerythritol. (author)

  5. [Folate, vitamin B12 and human health].

    Science.gov (United States)

    Brito, Alex; Hertrampf, Eva; Olivares, Manuel; Gaitán, Diego; Sánchez, Hugo; Allen, Lindsay H; Uauy, Ricardo

    2012-11-01

    During the past decade the role of folate and vitamin B12 in human nutrition have been under constant re-examination. Basic knowledge on the metabolism and interactions between these essential nutrients has expanded and multiple complexities have been unraveled. These micronutrients have shared functions and intertwined metabolic pathways that define the size of the "methyl donor" pool utilized in multiple metabolic pathways; these include DNA methylation and synthesis of nucleic acids. In Chile, folate deficiency is virtually nonexistent, while vitamin B12 deficiency affects approximately 8.5-51% depending on the cut-off value used to define deficiency. Folate is found naturally mainly in vegetables or added as folic acid to staple foods. Vitamin B12 in its natural form is present only in foods of animal origin, which is why deficit is more common among strict vegetarians and populations with a low intake of animal foods. Poor folate status in vulnerable women of childbearing age increases the risk of neural tube birth defects, so the critical time for the contribution of folic acid is several months before conception since neural tube closure occurs during the first weeks of life. The absorption of vitamin B12 from food is lower in older adults, who are considered to have higher risk of gastric mucosa atrophy, altered production of intrinsic factor and acid secretion. Deficiency of these vitamins is associated with hematological disorders. Vitamin B12 deficiency can also induce clinical and sub-clinical neurological and of other disorders. The purpose of this review is to provide an update on recent advances in the basic and applied knowledge of these vitamins relative to human health.

  6. Detection of vitamin B12 deficiency in older people by measuring vitamin B12 or the active fraction of vitamin B12, holotranscobalamin

    DEFF Research Database (Denmark)

    Clarke, Robert; Sherliker, Paul; Hin, Harold

    2007-01-01

    BACKGROUND: Impaired vitamin B(12) function and decreased vitamin B(12) status have been associated with neurological and cognitive impairment. Current assays analyze total vitamin B(12) concentration, only a small percentage of which is metabolically active. Concentrations of this active component......, carried on holotranscobalamin (holoTC), may be of greater relevance than total vitamin B(12). METHODS: We compared the utility of serum holoTC with conventional vitamin B(12) for detection of vitamin B(12) deficiency in a population-based study of older people, using increased methylmalonic acid (MMA......) concentrations as a marker of metabolic vitamin B(12) deficiency in the overall population (n = 2403) and in subsets with normal (n = 1651) and abnormal (n = 752) renal function. RESULTS: Among all participants, 6% had definite (MMA >0.75 micromol/L) and 16% had probable (MMA >0.45 micromol/L) metabolic vitamin...

  7. Vitamin B12: unique metalorganic compounds and the most complex vitamins.

    Science.gov (United States)

    Randaccio, Lucio; Geremia, Silvano; Demitri, Nicola; Wuerges, Jochen

    2010-04-30

    The chemistry and biochemistry of the vitamin B(12) compounds (cobalamins, XCbl) are described, with particular emphasis on their structural aspects and their relationships with properties and function. A brief history of B(12), reveals how much the effort of chemists, biochemists and crystallographers have contributed in the past to understand the basic properties of this very complex vitamin. The properties of the two cobalamins, the two important B(12) cofactors Ado- and MeCbl are described, with particular emphasis on how the Co-C bond cleavage is involved in the enzymatic mechanisms. The main structural features of cobalamins are described, with particular reference to the axial fragment. The structure/property relationships in cobalamins are summarized. The recent studies on base-off/base-on equilibrium are emphasized for their relevance to the mode of binding of the cofactor to the protein scaffold. The absorption, transport and cellular uptake of cobalamins and the structure of the B(12) transport proteins, IF and TC, in mammals are reviewed. The B(12) transport in bacteria and the structure of the so far determined proteins are briefly described. The currently accepted mechanisms for the catalytic cycles of the AdoCbl and MeCbl enzymes are reported. The structure and function of B(12) enzymes, particularly the important mammalian enzymes methyltransferase (MetH) and methyl-malonyl-coenzyme A mutase (MMCM), are described and briefly discussed. Since fast proliferating cells require higher amount of vitamin B(12) than that required by normal cells, the study of B(12 )conjugates as targeting agents has recently gained importance. Bioconjugates have been studied as potential agents for delivering radioisotopes and NMR probes or as various cytotoxic agents towards cancer cells in humans and the most recent studies are described. Specifically, functionalized bioconjugates are used as "Trojan horses" to carry into the cell the appropriate antitumour or diagnostic

  8. Vitamin B12: Unique Metalorganic Compounds and the Most Complex Vitamins

    Directory of Open Access Journals (Sweden)

    Lucio Randaccio

    2010-04-01

    Full Text Available The chemistry and biochemistry of the vitamin B12 compounds (cobalamins, XCbl are described, with particular emphasis on their structural aspects and their relationships with properties and function. A brief history of B12, reveals how much the effort of chemists, biochemists and crystallographers have contributed in the past to understand the basic properties of this very complex vitamin. The properties of the two cobalamins, the two important B12 cofactors Ado- and MeCbl are described, with particular emphasis on how the Co-C bond cleavage is involved in the enzymatic mechanisms. The main structural features of cobalamins are described, with particular reference to the axial fragment. The structure/property relationships in cobalamins are summarized. The recent studies on base-off/base-on equilibrium are emphasized for their relevance to the mode of binding of the cofactor to the protein scaffold. The absorption, transport and cellular uptake of cobalamins and the structure of the B12 transport proteins, IF and TC, in mammals are reviewed. The B12 transport in bacteria and the structure of the so far determined proteins are briefly described. The currently accepted mechanisms for the catalytic cycles of the AdoCbl and MeCbl enzymes are reported. The structure and function of B12 enzymes, particularly the important mammalian enzymes methyltransferase (MetH and methyl-malonyl-coenzymeA mutase (MMCM, are described and briefly discussed. Since fast proliferating cells require higher amount of vitamin B12 than that required by normal cells, the study of B12 conjugates as targeting agents has recently gained importance. Bioconjugates have been studied as potential agents for delivering radioisotopes and NMR probes or as various cytotoxic agents towards cancer cells in humans and the most recent studies are described. Specifically, functionalized bioconjugates are used as “Trojan horses” to carry into the cell the appropriate antitumour or

  9. Radioactively labelled vitamin B12

    Energy Technology Data Exchange (ETDEWEB)

    Charlton, J C; Lewis, A

    1976-12-01

    A method is described for preparing radioactively labelled vitamin B 12 (cyanocobalamin) by reacting ..cap alpha..-(5,6-dimethylbenzimidazolyl) hydrogenobamide with active (sup(57,58)Co) cobaltous ion. The latter may be in the form of cobaltous chloride or sulphate in aqueous or aqueous alcoholic medium. The reaction is effected by heating the reactants in darkness at pH 4 to 8. An excess of cyanide is added to convert the hydroxocobalamin formed to cyanocobalamin.

  10. Radioactively labelled vitamin B12

    International Nuclear Information System (INIS)

    Charlton, J.C.; Lewis, A.

    1976-01-01

    A method is described for preparing radioactively labelled vitamin B 12 (cyanocobalamin) by reacting α-(5,6-dimethylbenzimidazolyl) hydrogenobamide with active (sup(57,58)Co) cobaltous ion. The latter may be in the form of cobaltous chloride or sulphate in aqueous or aqueous alcoholic medium. The reaction is effected by heating the reactants in darkness at pH 4 to 8. An excess of cyanide is added to convert the hydroxocobalamin formed to cyanocobalamin. (U.K.)

  11. Investigations with a simplified method for radiometric determination of vitamin B12 in body fluids and feeding stuffs

    International Nuclear Information System (INIS)

    Menke, K.H.; Kohlberger, G.; Koenemund, A.

    1979-01-01

    A modified method for radiometrical determination of vitamin B 12 is described, which in difference to the known methods is based on measurement of free B 12 after absorption to albumin-coated charcoal instead of measurement of intrinsic factor B 12 -complex. The conditions for extraction from serum, milk, rumen-liquor and urine have been investigated and the effect of pH on IF-B 12 -binding in presence of these body fluids examined. Parallel microbiological determinations (O.m.- and L.1.-test) were in good correlation (r = 0,93-0,97) to radiometrically determined B 12 -contents in milk and rumen-liquor, but not to that in serum of dairy cows (r = 0,54-0,82). The analytical procedures are given in detail. (orig.) [de

  12. B-12 vitamin metabolism disorders

    International Nuclear Information System (INIS)

    Fabriciova, K.; Bzduch, V.; Behulova, D.; Skodova, J.; Holesova, D.; Ostrozlikova, M.; Schmidtova, K.; Kozich, V.

    2012-01-01

    Vitamin B-12 – cobalamin (Cbl) is a water soluble vitamin, which is synthesized by lower organisms. It cannot be synthesized by plants and higher organisms. Problem in the metabolic pathway of Cbl can be caused by its deficiency or by the deficiency of its last metabolites – adenosylcobalamin and methylcobalamin. Both reasons are presented by errors in the homocysteine and methylmalonyl-coenzyme A metabolism. Clinical symptoms of the Cbl metabolism disorders are: different neurological disorders, changes in haematological status (megaloblastic anemia, pancytopenia), symptoms of gastrointestinal tract (glossitis, loss of appetite, diarrhea) and changes in the immune system. In the article the authors describe the causes of Cbl metabolism disorders, its different diagnosis and treatment. They introduce the group of patients with these disorders, who were taken care of in the I st Paediatric Department of University Children Hospital for the last 5 years. (author)

  13. Vitamin B12-Containing Plant Food Sources for Vegetarians

    Science.gov (United States)

    Watanabe, Fumio; Yabuta, Yukinori; Bito, Tomohiro; Teng, Fei

    2014-01-01

    The usual dietary sources of Vitamin B12 are animal-derived foods, although a few plant-based foods contain substantial amounts of Vitamin B12. To prevent Vitamin B12 deficiency in high-risk populations such as vegetarians, it is necessary to identify plant-derived foods that contain high levels of Vitamin B12. A survey of naturally occurring plant-derived food sources with high Vitamin B12 contents suggested that dried purple laver (nori) is the most suitable Vitamin B12 source presently available for vegetarians. Furthermore, dried purple laver also contains high levels of other nutrients that are lacking in vegetarian diets, such as iron and n-3 polyunsaturated fatty acids. Dried purple laver is a natural plant product and it is suitable for most people in various vegetarian groups. PMID:24803097

  14. Vitamin B12-Containing Plant Food Sources for Vegetarians

    Directory of Open Access Journals (Sweden)

    Fumio Watanabe

    2014-05-01

    Full Text Available The usual dietary sources of Vitamin B12 are animal-derived foods, although a few plant-based foods contain substantial amounts of Vitamin B12. To prevent Vitamin B12 deficiency in high-risk populations such as vegetarians, it is necessary to identify plant-derived foods that contain high levels of Vitamin B12. A survey of naturally occurring plant-derived food sources with high Vitamin B12 contents suggested that dried purple laver (nori is the most suitable Vitamin B12 source presently available for vegetarians. Furthermore, dried purple laver also contains high levels of other nutrients that are lacking in vegetarian diets, such as iron and n-3 polyunsaturated fatty acids. Dried purple laver is a natural plant product and it is suitable for most people in various vegetarian groups.

  15. Vitamin B-12 and Perinatal Health.

    Science.gov (United States)

    Finkelstein, Julia L; Layden, Alexander J; Stover, Patrick J

    2015-09-01

    Vitamin B-12 deficiency (importance of adequate vitamin B-12 status periconceptionally and during pregnancy cannot be overemphasized, given its fundamental role in neural myelination, brain development, and growth. Infants born to vitamin B-12-deficient women may be at increased risk of neural tube closure defects, and maternal vitamin B-12 insufficiency (pregnancy complications, few prospective studies and, to our knowledge, only 1 randomized trial have examined the effects of vitamin B-12 supplementation during pregnancy. The role of vitamin B-12 in the etiology of adverse perinatal outcomes needs to be elucidated to inform public health interventions. © 2015 American Society for Nutrition.

  16. Simultaneous radiodetermination of folate and vitamin B12

    International Nuclear Information System (INIS)

    Gutcho, S.; Mansbach, L.

    1978-01-01

    The invention concerns a method to simultaneously investigate or determine folate and vitamin B12. The differentiation between both compounds is based on the use of radioactive tracers; a radio-iodized folic acid is used as folate tracer; vitamin B12 can be labelled with 57 Co. (VJ) [de

  17. Metformin increases liver accumulation of vitamin B12 - An experimental study in rats

    DEFF Research Database (Denmark)

    Greibe, E; Miller, J W; Foutouhi, S H

    2013-01-01

    AIMS/HYPOTHESIS: Patients treated with metformin exhibit low levels of plasma vitamin B(12) (B(12)), and are considered at risk for developing B(12) deficiency. In this study, we investigated the effect of metformin treatment on B(12) uptake and distribution in rats. METHODS: Sprague Dawley rats (n...... that metformin has no decreasing effect on the B(12) absorption. CONCLUSIONS/INTERPRETATION: These results show that metformin treatment increases liver accumulation of B(12), thereby resulting in decreases in circulating B(12) and kidney accumulation of the vitamin. Our data questions whether the low plasma B......(12) observed in patients treated with metformin reflects impaired B(12) status, and rather suggests altered tissue distribution and metabolism of the vitamin....

  18. 7 CFR 15b.12 - Discrimination prohibited.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15b.12 Section 15b.12... ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Employment Practices § 15b.12 Discrimination prohibited. (a... discrimination in employment under any program or activity receiving assistance from this Department. (2) A...

  19. Fuzzy modeling for Vitamin B12 deficiency

    NARCIS (Netherlands)

    Wilbik, A.M.; van Loon, S.L.M.; Boer, A.K.; Kaymak, U.; Scharnhorst, V.; Carvalho, J.; Lesot, M.J.; Kaymak, U.; Vieira, S.; Bouchon-Meunier, B.; Yager, R.

    2016-01-01

    Blood vitamin B12 levels are not representative for actual vitamin B12 status in tissue. Instead plasma methylmalonic acid (MMA) levels can be measured because MMA concentrations increase relatively early in the course of vitamin B12 deficiency. However, MMA levels in plasma may also be increased

  20. Tunable electromagnetically induced absorption based on graphene

    Science.gov (United States)

    Cao, Maoyong; Wang, Tongling; Zhang, Huiyun; Zhang, Yuping

    2018-04-01

    In this paper, an electronically induced absorption (EIA) structure based on graphene at the infrared frequency is proposed. A pair of nanorods is coupled to a ring resonator, resulting in electronically induced transparency (EIT), and then, Babinet's principle is applied to transform the EIT structure into an EIA structure. Based on the bright and dark modes of the coupling schemes, the adjustment of the coupling strength between the dark and bright modes can be achieved by changing the asymmetry degree. In addition, the transparency window and the absorption peak can be tuned by changing the Fermi energy of graphene. This graphene-based EIA structure can develop the path in narrow-band filtering and, absorptive switching in the future.

  1. Radioassay of vitamin B-12 employing bentonite

    International Nuclear Information System (INIS)

    Lewin, N.; Fries, J.E.; Richards, C.S.

    1976-01-01

    Radioassay for vitamin B-12 using the unknown quantity of non-radioactive vitamin B-12 released from serum mixed with the radioactivity of a known quantity of radioactive vitamin B-12 tracer. A solution of intrinsic factor having a binding capacity less than the quantity of serum vitamin B-12 and radioactive vitamin B-12 is used to bind a portion of the vitamin B-12 mixture. The vitamin B-12 not bound to intrinsic factor is removed by addition of a bentonite-containing tablet. The quantity of radioactive vitamin B-12 bound to intrinsic factor is compared with standard values and the unknown serum vitamin B-12 obtained. In the steps of the procedure the acid assay medium is pre-combined with the radioactive tracer so that the radioactive vitamin B-12 tracer receives the same treatment as serum vitamin B-12. Certain of the other reagent solutions are pre-combined and the concentration of the components adjusted so that the volume used of each of these other reagent solutions is the same in different assay steps. Thus, fewer pipetting steps are necessary. 7 claims, 1 drawing figure

  2. Forms and Amounts of Vitamin B12 in Infant Formula: A Pilot Study.

    Directory of Open Access Journals (Sweden)

    Eva Greibe

    Full Text Available Infant formula is based on cow's milk and designed to mimic breast milk for substitution. Vitamin B12 (B12 is bound to proteins in both breast milk and cow's milk, and in milk from both species the vitamin occurs mainly in its natural form such as hydroxo-B12 with little or no synthetic B12 (cyano-B12. Here we test commercially available infant formulas.Eleven commercially available infant formulas were measured for content of B12 and analyzed for the presence of B12-binding proteins and forms of B12 using size exclusion chromatography and HPLC.All infant formulas contained B12 by and large in accord with the informations given on the package inserts. None of the formulas contained protein-bound B12, and cyano-B12 accounted for 19-78% of the total amount of B12 present, while hydroxo-B12 constituted more or less the rest.This pilot study shows that infant formula differs from breast milk in providing the infant with free B12, rather than protein-bound B12, and by a relative high content of cyano-B12. The consequence of supplying the infant with synthetic cyano-B12 remains to be elucidated.

  3. Forms and Amounts of Vitamin B12 in Infant Formula: A Pilot Study.

    Science.gov (United States)

    Greibe, Eva; Nexo, Ebba

    2016-01-01

    Infant formula is based on cow's milk and designed to mimic breast milk for substitution. Vitamin B12 (B12) is bound to proteins in both breast milk and cow's milk, and in milk from both species the vitamin occurs mainly in its natural form such as hydroxo-B12 with little or no synthetic B12 (cyano-B12). Here we test commercially available infant formulas. Eleven commercially available infant formulas were measured for content of B12 and analyzed for the presence of B12-binding proteins and forms of B12 using size exclusion chromatography and HPLC. All infant formulas contained B12 by and large in accord with the informations given on the package inserts. None of the formulas contained protein-bound B12, and cyano-B12 accounted for 19-78% of the total amount of B12 present, while hydroxo-B12 constituted more or less the rest. This pilot study shows that infant formula differs from breast milk in providing the infant with free B12, rather than protein-bound B12, and by a relative high content of cyano-B12. The consequence of supplying the infant with synthetic cyano-B12 remains to be elucidated.

  4. Atypical B12 Deficiency with Nonresolving Paraesthesia

    Directory of Open Access Journals (Sweden)

    S. Haider

    2013-01-01

    Full Text Available Vitamin B12 deficiency can present with various hematological, gastrointestinal and neurological manifestations. We report a case of elderly female who presented with neuropathy and vitamin B12 deficiency where the final work-up revealed polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS. This case suggests that, although POEMS syndrome is a rare entity, it can present with vitamin-B12 deficiency and thus specific work up for early diagnosis of POEMS should be considered in patients with B12 deficiency unresponsive to therapy.

  5. Identification of differentially expressed proteins in vitamin B 12

    Directory of Open Access Journals (Sweden)

    Swati Varshney

    2015-01-01

    Full Text Available Background: Vitamin B 12 (cobalamin is a water-soluble vitamin generally synthesized by microorganisms. Mammals cannot synthesize this vitamin but have evolved processes for absorption, transport and cellular uptake of this vitamin. Only about 30% of vitamin B 12 , which is bound to the protein transcobalamin (TC (Holo-TC [HoloTC] enters into the cell and hence is referred to as the biologically active form of vitamin B 12 . Vitamin B 12 deficiency leads to several complex disorders, including neurological disorders and anemia. We had earlier shown that vitamin B 12 deficiency is associated with coronary artery disease (CAD in Indian population. In the current study, using a proteomics approach we identified proteins that are differentially expressed in the plasma of individuals with low HoloTC levels. Materials and Methods: We used isobaric-tagging method of relative and absolute quantitation to identify proteins that are differently expressed in individuals with low HoloTC levels when compared to those with normal HoloTC level. Results: In two replicate isobaric tags for relative and absolute quantitation experiments several proteins involved in lipid metabolism, blood coagulation, cholesterol metabolic process, and lipoprotein metabolic process were found to be altered in individuals having low HoloTC levels. Conclusions: Our study indicates that low HoloTc levels could be a risk factor in the development of CAD.

  6. How common is vitamin B-12 deficiency?

    Science.gov (United States)

    Allen, Lindsay H

    2009-02-01

    In considering the vitamin B-12 fortification of flour, it is important to know who is at risk of vitamin B-12 deficiency and whether those individuals would benefit from flour fortification. This article reviews current knowledge of the prevalence and causes of vitamin B-12 deficiency and considers whether fortification would improve the status of deficient subgroups of the population. In large surveys in the United States and the United Kingdom, approximately 6% of those aged > or =60 y are vitamin B-12 deficient (plasma vitamin B-12 life. In developing countries, deficiency is much more common, starting in early life and persisting across the life span. Inadequate intake, due to low consumption of animal-source foods, is the main cause of low serum vitamin B-12 in younger adults and likely the main cause in poor populations worldwide; in most studies, serum vitamin B-12 concentration is correlated with intake of this vitamin. In older persons, food-bound cobalamin malabsorption becomes the predominant cause of deficiency, at least in part due to gastric atrophy, but it is likely that most elderly can absorb the vitamin from fortified food. Fortification of flour with vitamin B-12 is likely to improve the status of most persons with low stores of this vitamin. However, intervention studies are still needed to assess efficacy and functional benefits of increasing intake of the amounts likely to be consumed in flour, including in elderly persons with varying degrees of gastric atrophy.

  7. Vitamin B12 and Folate Test

    Science.gov (United States)

    ... offer the folate test. Can taking too many vitamin B12 and folic acid supplements hurt me? Not usually. Since B12 and folic acid are water-soluble, the body will rid itself of any excess by excreting it in the urine. However, taking ...

  8. [Vitamin B12 deficiency: what's new?].

    Science.gov (United States)

    Braillard, O; Casini, A; Samii, K; Rufenacht, P; Junod, Perron N

    2012-09-26

    Vitamin B12 screening is only recommended among symptomatic patients or in those with risk factors. The main cause of vitamin B12 deficiency is the food cobalamin malabsorption syndrom. Holotranscobalamin is a more reliable marker than cyanocobalamin to confirm vitamin B12 deficiency, but it has not been validated yet in complex situations. An autoimmune gastritis must be excluded in the absence of risk factors but in the presence of a probable deficiency. Oral substitution treatment is effective but requires excellent therapeutic compliance and close follow-up to monitor the response to treatment. It has not yet been studied among patients suffering from severe symptoms, inflammatory bowel disease and ileal resection.

  9. Vitamin B12 among Vegetarians: Status, Assessment and Supplementation.

    Science.gov (United States)

    Rizzo, Gianluca; Laganà, Antonio Simone; Rapisarda, Agnese Maria Chiara; La Ferrera, Gioacchina Maria Grazia; Buscema, Massimo; Rossetti, Paola; Nigro, Angela; Muscia, Vincenzo; Valenti, Gaetano; Sapia, Fabrizio; Sarpietro, Giuseppe; Zigarelli, Micol; Vitale, Salvatore Giovanni

    2016-11-29

    Cobalamin is an essential molecule for humans. It acts as a cofactor in one-carbon transfers through methylation and molecular rearrangement. These functions take place in fatty acid, amino acid and nucleic acid metabolic pathways. The deficiency of vitamin B12 is clinically manifested in the blood and nervous system where the cobalamin plays a key role in cell replication and in fatty acid metabolism. Hypovitaminosis arises from inadequate absorption, from genetic defects that alter transport through the body, or from inadequate intake as a result of diet. With the growing adoption of vegetarian eating styles in Western countries, there is growing focus on whether diets that exclude animal foods are adequate. Since food availability in these countries is not a problem, and therefore plant foods are sufficiently adequate, the most delicate issue remains the contribution of cobalamin, which is poorly represented in plants. In this review, we will discuss the status of vitamin B12 among vegetarians, the diagnostic markers for the detection of cobalamin deficiency and appropriate sources for sufficient intake, through the description of the features and functions of vitamin B12 and its absorption mechanism.

  10. Vitamin B12 among Vegetarians: Status, Assessment and Supplementation

    Directory of Open Access Journals (Sweden)

    Gianluca Rizzo

    2016-11-01

    Full Text Available Cobalamin is an essential molecule for humans. It acts as a cofactor in one-carbon transfers through methylation and molecular rearrangement. These functions take place in fatty acid, amino acid and nucleic acid metabolic pathways. The deficiency of vitamin B12 is clinically manifested in the blood and nervous system where the cobalamin plays a key role in cell replication and in fatty acid metabolism. Hypovitaminosis arises from inadequate absorption, from genetic defects that alter transport through the body, or from inadequate intake as a result of diet. With the growing adoption of vegetarian eating styles in Western countries, there is growing focus on whether diets that exclude animal foods are adequate. Since food availability in these countries is not a problem, and therefore plant foods are sufficiently adequate, the most delicate issue remains the contribution of cobalamin, which is poorly represented in plants. In this review, we will discuss the status of vitamin B12 among vegetarians, the diagnostic markers for the detection of cobalamin deficiency and appropriate sources for sufficient intake, through the description of the features and functions of vitamin B12 and its absorption mechanism.

  11. Vitamin B12 and Semen Quality.

    Science.gov (United States)

    Banihani, Saleem Ali

    2017-06-09

    Various studies have revealed the effects of vitamin B12, also named cobalamin, on semen quality and sperm physiology; however, these studies collectively are still unsummarized. Here, we systematically discuss and summarize the currently understood role of vitamin B12 on semen quality and sperm physiology. We searched the Web of Science, PubMed, and Scopus databases for only English language articles or abstracts from September 1961 to March 2017 (inclusive) using the key words "vitamin B12" and "cobalamin" versus "sperm". Certain relevant references were included to support the empirical as well as the mechanistic discussions. In conclusion, the mainstream published work demonstrates the positive effects of vitamin B12 on semen quality: first, by increasing sperm count, and by enhancing sperm motility and reducing sperm DNA damage, though there are a few in vivo system studies that have deliberated some adverse effects. The beneficial effects of vitamin B12 on semen quality may be due to increased functionality of reproductive organs, decreased homocysteine toxicity, reduced amounts of generated nitric oxide, decreased levels of oxidative damage to sperm, reduced amount of energy produced by spermatozoa, decreased inflammation-induced semen impairment, and control of nuclear factor-κB activation. However, additional research, mainly clinical, is still needed to confirm these positive effects.

  12. Vitamin B12 and Semen Quality

    Directory of Open Access Journals (Sweden)

    Saleem Ali Banihani

    2017-06-01

    Full Text Available Various studies have revealed the effects of vitamin B12, also named cobalamin, on semen quality and sperm physiology; however, these studies collectively are still unsummarized. Here, we systematically discuss and summarize the currently understood role of vitamin B12 on semen quality and sperm physiology. We searched the Web of Science, PubMed, and Scopus databases for only English language articles or abstracts from September 1961 to March 2017 (inclusive using the key words “vitamin B12” and “cobalamin” versus “sperm”. Certain relevant references were included to support the empirical as well as the mechanistic discussions. In conclusion, the mainstream published work demonstrates the positive effects of vitamin B12 on semen quality: first, by increasing sperm count, and by enhancing sperm motility and reducing sperm DNA damage, though there are a few in vivo system studies that have deliberated some adverse effects. The beneficial effects of vitamin B12 on semen quality may be due to increased functionality of reproductive organs, decreased homocysteine toxicity, reduced amounts of generated nitric oxide, decreased levels of oxidative damage to sperm, reduced amount of energy produced by spermatozoa, decreased inflammation-induced semen impairment, and control of nuclear factor-κB activation. However, additional research, mainly clinical, is still needed to confirm these positive effects.

  13. Interaction of conjugated bile acids and detergents with a radiosorbent assay of vitamin B-12

    International Nuclear Information System (INIS)

    Andersen, K.-J.; Romslo, I.

    1977-01-01

    The effect of conjugated bile acids and detergents on the radiosorbent technique for the determination of vitamin B-12 activity is reported. It is shown that whereas the non-ionic detergent Triton X-100 has no effect on the vitamin B-12-radiosorbent assay, the addition of ionic detergents, e.g. glycocholic acid, taurocholic acid or sodium lauryl sulfate, results in a falsely-elevated vitamin B-12 activity presumably due to the disruption of the binding of vitamin B-12 to the intrinsic factor-Sephadex complex. This effect may be of importance not only to the radiosorbent assaying of vitamin B-12, but to the in vivo intestinal absorption of vitamin B-12 as well

  14. Genetic determinants of serum vitamin B12 and their relation to body mass index

    DEFF Research Database (Denmark)

    Allin, Kristine H.; Friedrich, Nele; Pietzner, Maik

    2017-01-01

    for associations between (1) serum vitamin B12 levels and body mass index (BMI), (2) genetic variants and serum vitamin B12 levels, and (3) genetic variants and BMI. The effect of a genetically determined decrease in serum vitamin B12 on BMI was estimated by instrumental variable regression. Decreased serum......Lower serum vitamin B12 levels have been related to adverse metabolic health profiles, including adiposity. We used a Mendelian randomization design to test whether this relation might be causal. We included two Danish population-based studies (ntotal = 9311). Linear regression was used to test...... vitamin B12 associated with increased BMI (P vitamin B12 associated variants associated strongly with serum vitamin B12 (P vitamin B12...

  15. Woodward's Synthesis of Vitamin B12

    Indian Academy of Sciences (India)

    consistently demonstrating the powerful use of logical reason- ing where it was customary to abandon such approaches. Barton further says, "We were taught to think that mechanism had nothing to do with 'real' Chemistry. With one lecture, Wood- ward showed us the contrary." Vitamin B12 is a large and complex molecule ...

  16. Mendelian randomisation study of the associations of vitamin B12 and folate genetic risk scores with blood pressure and fasting serum lipid levels in three Danish population-based studies

    DEFF Research Database (Denmark)

    Husemoen, L L N; Skaaby, T; Thuesen, B H

    2016-01-01

    BACKGROUND/OBJECTIVES: The aim was to examine the association of genetic risk scores (GRSs) of vitamin B12 and folate-associated variants with blood pressure and lipids. SUBJECTS/METHODS: The study included 12 532 adults from three population-based studies (Inter99, Health2006 and Dan-MONICA10) c...... association between folate and HDL cholesterol exists.European Journal of Clinical Nutrition advance online publication, 24 February 2016; doi:10.1038/ejcn.2016.5....... and lipid-related outcomes in the combined analyses. Increasing number of folate increasing alleles was associated with increased high-density lipoprotein (HDL) cholesterol concentrations (β coefficient (95% CI, P-value) for regression of log-transformed HDL on the weighted GRSs, 0.081 (0.015, 0.148), P=0...

  17. Production of vitamin B12 and labeled vitamin B12 by Streptomyces griseus

    International Nuclear Information System (INIS)

    Mazaheri Tehrani, M.; Ghorbanzadeh Mashkani, S.; Tajer Mohammad Ghazvini, P.; Nazari, A.; Aflakee, F.

    2009-01-01

    In this study, the production of labeled vitamin B 12 with one strain of actinomycet in a novel synthetic medium by batch fermentation method was investigated. After releasing vitamin B 12 from microbial cells, the solution containing cobalamin analogues was fixed on amberlite XAD-4 exchanger and eluted by various solutions. Vitamin B 12 in the collected fractions were measured by HPLC method and also in order to confirm the existence of cobalamin compounds in the samples, TLC technique was used. In the optimal conditions, production of vitamin B 12 by this microorganism was 1456μg/1. The best recoveries of vitamin B 12 from the column were obtained when the column was eluted by ethanol followed by acetone. The R f , values for cyanocobalamin and methylcobalamin, produced by this microorganism were the same as the standard values of R f . The desorption of labeled vitamine B 12 was carried out by different eluants, including acetone, ethanol (absolute), ethanol 25% and deionized water. The activity of labeled vitamin B 12 was 8.55, 6.90, 0.79, 5.75 Bq/ml, respectively. Therefore, the total specific activity of 21.99 Bq/ml was obtained for labeled vitamin B 12 .

  18. The Ligand Substitution Reactions of Hydrophobic Vitamin B12 ...

    African Journals Online (AJOL)

    South African Journal of Chemistry ... The equilibrium constants, K, for the reaction of five-membered heterocyclic nitrogenous bases (the azoles imidazole, pyrazole and 1,2,4-triazole) with displacement of ... Keywords: Hydrophobic vitamin B12, cobalt corrinoids, equilibrium constants, solvent polarity, trans influence.

  19. Maximal load of the vitamin B12 transport system

    DEFF Research Database (Denmark)

    Lildballe, Dorte L; Mutti, Elena; Birn, Henrik

    2012-01-01

    Several studies suggest that the vitamin B12 (B12) transport system can be used for the cellular delivery of B12-conjugated drugs, also in long-term treatment Whether this strategy will affect the endogenous metabolism of B12 is not known. To study the effect of treatment with excess B12...

  20. Vitamin B12 and eicosanoids in insects

    International Nuclear Information System (INIS)

    Wakayama, J.E.

    1985-01-01

    Vitamin B 12 was not detected in the house fly, Musca domestica, which apparently cannot interconvert propionate and succinate. In contrast, the termite readily interconverts succinate and methylmalonate, and contains high amounts of vitamin B 12 . The intestinal bacteria were the major source of vitamin B 12 in the termite, Coptotermes formosanus. The presence of arachidonic acid (20:4) and eicosatrienoic acid (20:3,n-6) at low levels in adult male and female house flies was demonstrated by chemical ionization-gas chromatography-mass spectrometry. After injection, over 80% of 20:4 was rapidly incorporated into the phospholipid (PL) fraction. Over 80% of the sequestered 20:4 was in the 2-position of PLs. The 20:4 was injected into the insect or was included in the diet prior to administration of [ 3 H] 20:4; large amounts of radioactivity were recovered in the triacylglycerol and free fatty acid fractions. Arachidonic acid (20:4) injected into house flies was rapidly converted to prostaglandins, and was also catabolized rapidly. Radiolabeled 20:4 injected into the hemolymph was incorporated into the reproductive tissues of male insects. About 2.1% of the total radioactivity from [ 3 H] 20:4 injected into males just prior to mating was transferred to females during mating

  1. Vitamin B-12 supplementation of rural Mexican women changes biochemical B-12 status indicators but does not affect hematology or a bone turnover marker

    Science.gov (United States)

    Based on the high prevalence of low serum vitamin B-12 concentrations and low dietary intake of the vitamin in Latin American studies including research in Mexico, it appears that vitamin B-12 deficiency is common. Whether this is associated with adverse effects on human function is unknown. To eval...

  2. Forms of vitamin B12 in radioisotope dilution assays

    International Nuclear Information System (INIS)

    Begley, J.A.; Hall, C.A.

    1981-01-01

    Since the presence of analogues of vitamin B 12 (B 12 , cobalamin, Cbl) has been postulated as the basis for the high values obtained by some radioisotope dilution assays (RIDA) of serum Cbl, serum was examined for analogues. None could be demonstrated in the extracts of serum prepared for RIDA as sought by both direct and indirect techniques. The natural forms of serum Cbl were converted to cyanocobalamin (CN Cbl) by this process of extraction which included cyanide (CN). The correctly performed RIDA for Cbl based on R binder gave higher values than a RIDA based on intrinsic factor or than by bioassay. By exclusion, the difference appeared to be due to unidentified factors rather than the presence of analogues. (author)

  3. 21 CFR 862.1810 - Vitamin B12 test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vitamin B12 test system. 862.1810 Section 862.1810....1810 Vitamin B12 test system. (a) Identification. A vitamin B12 test system is a device intended to measure vitamin B12 in serum, plasma, and urine. Measurements obtained by this device are used in the...

  4. New method for the radioactive determination of vitamin B12

    International Nuclear Information System (INIS)

    Lewin, Nathan; Fries, J.E.; Richards, C.S.

    1975-01-01

    A description is given of a method for the radioactive determination of vitamin B12 in a sample solution of serum in which a radioactive tracer of vitamin B12 and the vitamin B12 of the serum compete with respect to an intrinsic factor of limited linking capacity. The free radioactive vitamin B12 and the free vitamin B12 of the serum are separated from the intrinsic factor and from the radioactive vitamin B12 and from the serum vitamin B12 linked to this factor, before the radioactivity is measured against standard values. The method consists in separating the free radioactive vitamin B12 and the free serum vitamin B12 of the intrinsic factor and portions of radioactive and serum vitamin B12 linked to this factor, by adding an adequate quantity of bentonite to adsorb the free radioactive vitamin B12 and free serum vitamin B12 so that the intrinsic factor surface floating solution in association with the linked radioactive vitamin B12 and the linked serum vitamin B12 may be physically isolated from the solid bentonite that has adsorbed the free radioactive vitamin B12 and the free serum vitamin B12 [fr

  5. Linear photophysics, two-photon absorption and femtosecond transient absorption spectroscopy of styryl dye bases

    Energy Technology Data Exchange (ETDEWEB)

    Shaydyuk, Ye.O. [Institute of Physics, Prospect Nauki, 46, Kyiv-28 03028 Ukraine (Ukraine); Levchenko, S.M. [Institute of Molecular Biology and Genetics, 150, Akademika Zabolotnoho Str., Kyiv 036803 (Ukraine); Kurhuzenkau, S.A. [Department of Chemistry, University of Parma, Parco Area delle Scienze 17/A, Parma 43124 (Italy); Anderson, D. [NanoScienece Technology Center, University of Central Florida, 12424 Research Parkway, PAV400, Orlando, FL 32826 (United States); Department of Chemistry, University of Central Florida, 4111 Libra Drive, PSB225, Orlando, FL 32816 (United States); Masunov, A.E. [NanoScienece Technology Center, University of Central Florida, 12424 Research Parkway, PAV400, Orlando, FL 32826 (United States); Department of Chemistry, University of Central Florida, 4111 Libra Drive, PSB225, Orlando, FL 32816 (United States); South Ural State University, Lenin pr. 76, Chelyabinsk 454080 (Russian Federation); Department of Condensed Matter Physics, National Research Nuclear University MEPhI, Kashirskoye shosse 31, Moscow 115409 (Russian Federation); Photochemistry Center RAS, ul. Novatorov 7a, Moscow 119421 (Russian Federation); Kachkovsky, O.D.; Slominsky, Yu.L.; Bricks, J.L. [Insitute of Organic Chemistry, Murmanskaya Street, 5, Kyiv 03094 (Ukraine); Belfield, K.D. [College of Science and Liberal Arts, New Jersey Institute of Technology, University Heights, Newark, NJ 07102 (United States); School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, 710062 (China); Bondar, M.V., E-mail: mbondar@mail.ucf.edu [Institute of Physics, Prospect Nauki, 46, Kyiv-28 03028 Ukraine (Ukraine)

    2017-03-15

    The steady-state and time-resolved linear spectral properties, two-photon absorption spectra and fast relaxation processes in the excited states of styryl base-type derivatives were investigated. The nature of linear absorption, fluorescence and excitation anisotropy spectra were analyzed in solvents of different polarity at room temperature and specific dependence of the solvatochromic behavior on the donor-acceptor strength of the terminal substituents was shown. Two-photon absorption (2PA) efficiency of styryl dye bases was determined in a broad spectral range using two-photon induced fluorescence technique, and cross-sections maxima of ~ 100 GM were found. The excited state absorption (ESA) and fast relaxation processes in the molecular structures were investigated by transient absorption femtosecond pump-probe methodology. The role of twisted intramolecular charge transfer (TICT) effect in the excited state of styryl dye base with dimethylamino substituent was shown. The experimental spectroscopic data were also verified by quantum chemical calculations at the Time Dependent Density Functional Theory level, combined with a polarizable continuum model.

  6. TD-DFT Insight into Photodissociation of Co-C Bond in Coenzyme B12

    Directory of Open Access Journals (Sweden)

    Pawel Michal Kozlowski

    2014-02-01

    Full Text Available Coenzyme B12 (AdoCbl is one of the most biologically active forms of vitamin B12, and continues to be a topic of active research interest. The mechanism of Co-C bond cleavage in AdoCbl, and the corresponding enzymatic reactions are however, not well understood at the molecular level. In this work, time-dependent density functional theory (TD-DFT has been applied to investigate the photodissociation of coenzyme B12. To reduce computational cost, while retaining the major spectroscopic features of AdoCbl, a truncated model based on ribosylcobalamin (RibCbl was used to simulate Co-C photodissociation. Equilibrium geometries of RibCbl were obtained by optimization at the DFT/BP86/TZVP level of theory, and low-lying excited states were calculated by TD-DFT using the same functional and basis set. The calculated singlet states, and absorption spectra were simulated in both the gas phase, and water, using the polarizable continuum model (PCM. Both spectra were in reasonable agreement with experimental data, and potential energy curves based on vertical excitations were plotted to explore the nature of Co-C bond dissociation. It was found that a repulsive 3(σCo-C → σ*Co-C triplet state became dissociative at large Co-C bond distance, similar to a previous observation for methylcobalamin (MeCbl. Furthermore, potential energy surfaces (PESs obtained as a function of both Co-CRib and Co-NIm distances, identify the S1 state as a key intermediate generated during photoexcitation of RibCbl, attributed to a mixture of a MLCT (metal-to-ligand charge transfer and a σ bonding-ligand charge transfer (SBLCT states.

  7. Measurements of vitamin B12 in human blood serum using resonance Raman spectroscopy

    Science.gov (United States)

    Tsiminis, G.; Schartner, E. P.; Brooks, J. L.; Hutchinson, M. R.

    2016-12-01

    Vitamin B12 (cobalamin and its derivatives) deficiency has been identified as a potential modifiable risk factor for dementia and Alzheimer's disease. Chronic deficiency of vitamin B12 has been significantly associated with an increased risk of cognitive decline. An effective and efficient method for measuring vitamin B12 concentration in human blood would enable ongoing tracking and assessment of this potential modifiable risk factor. In this work we present an optical sensor based on resonance Raman spectroscopy for rapid measurements of vitamin B12 in human blood serum. The measurement takes less than a minute and requires minimum preparation (centrifuging) of the collected blood samples.

  8. Radiolysis of cyanocobalamin (vitamin B12)

    International Nuclear Information System (INIS)

    Juanchi, X.; Albarran, G.; Negron-Mendoza, A.

    2000-01-01

    Research on the radiolysis of vitamins is of considerable interest since these compounds are important nutritional constituents in foods and in dietetic supplements. In spite of these considerations there are few data and very often difficult to compare for the radiolytic behavior of vitamins. In this work we focused our attention on to the study of the radiolysis of cyanocobalamin (vitamin B 12 ) in solid state and in aqueous solutions. The procedure was followed by HPLC and UV-spectroscopy. The results obtained in aqueous solutions showed a dependence of the decomposition as a linear function of the dose. The G of decomposition for a 1x10 -5 M solution was 3.3. In the solid state the vitamin was very stable towards the irradiation in the conditions used in this study with a G=2.1x10 -3 . A study made with Serratia marcescens as a microbiological contaminant showed that at the sterilization dose there is a destruction of the vitamin in aqueous solution. In the solid state the degree of decomposition was 7%. (author)

  9. Status of Vitamin B12 and Folate among the Urban Adult Population in South India.

    Science.gov (United States)

    Sivaprasad, M; Shalini, T; Balakrishna, N; Sudarshan, M; Lopamudra, P; Suryanarayana, P; Arlappa, N; Ravikumar, B P; Radhika, M S; Reddy, G Bhanuprakash

    2016-01-01

    Deficiency of vitamin B12 (B12) and folate (FA) leads to a wide spectrum of disorders that affect all age groups. However, reports on B12 and FA status in healthy adults in India are limited. Hence, we determined the plasma levels and dietary intake of B12 and FA in the adult population. We conducted a community-based cross-sectional study in an urban setup among 630 apparently healthy adults distributed into 3 age groups: 21-40, 41-60 and >60 years. Plasma concentrations of B12 and FA were analyzed by radio immunoassay and dietary intake by 24-hour recall method. The overall prevalence of FA deficiency was 12%, but there was no significant difference in plasma FA concentrations among the groups. While the overall prevalence of B12 deficiency was 35%, it was significantly higher in the 21-40 (44%) and 41-60 age groups (40%) when compared with the >60 group (30%). B12 deficiency was higher in vegetarians (54%) compared to those consuming mixed diet (31%), and the reverse was the case with FA. However, the dietary intakes of FA and B12 were not significantly different among the groups. These results indicate a higher prevalence of B12 deficiency in apparently healthy adults in an urban setup. © 2015 S. Karger AG, Basel.

  10. Vitamin B12 status and the effects of vitamin B12 supplementation during the first year of life of spring calves from pasture-fed dairy herds.

    Science.gov (United States)

    Grace, N D; Knowles, S O; Nortjé, R

    2014-09-01

    To determine the vitamin B12 status of dairy calves during their first year of life, and to evaluate the benefits of vitamin B12 supplementation. In Experiment I, 20 17-day-old heifer calves from the AgResearch Flock House herd were monitored until 198 days old. On Days 0 and 90 of the study, half of the animals received an injection of microencapsulated vitamin B12 at 0.12 mg/kg bodyweight. All received colostrum, milk replacer and calf meal, with ad libitum access to pasture. At regular intervals the calves were weighed and serum collected for vitamin B12 measurement. In Experiment II at Flock House and the adjacent Landcorp Tangimoana station, 80 150-day-old heifer calves were monitored until 342 days old. On Days 0 and 97, half of the animals received vitamin B12 as per Experiment I. At regular intervals samples were collected from 12 calves per group, to determine concentrations of vitamin B12 in serum. Mean concentration of vitamin B12 in milk replacer was 63 (SE 4) µg/kg dry matter (DM). Cobalt concentrations in calf meal were 0.45-1.58 and 0.07-0.28 mg/kg DM in pastures. From 17 to 198 days of age (Experiment I) mean concentrations of vitamin B12 in serum of the control group decreased from 119 (SE 8) to 57 (SE 5) pmol/L. From 150 to 342 days of age (Experiment II), overall mean concentrations of the control groups at Flock House and Tangimoana were 90 (SE 2) and 96 (SE 3) pmol/L, respectively. Vitamin B12 injections increased (ppasture-based diet. Supplementation increased concentrations of vitamin B12 in serum but did not improve liveweight gains. Under this calf rearing system, vitamin B12 deficiency is unlikely to occur prior to weaning, and vitamin B12 supplementation is unlikely to increase growth rates of grazing calves when concentrations of vitamin B12 in serum are > 90 pmol/L.

  11. Photon absorption of calcium phosphate-based dental biomaterials

    International Nuclear Information System (INIS)

    Singh, V. P.; Badiger, N. M.; Tekin, H. O.; Kara, U.; Vega C, H. R.; Fernandes Z, M. A.

    2017-10-01

    Effective atomic number and mass energy absorption buildup factors for four calcium phosphate-based biomaterials used in dental treatments were calculated for 0.015 to 15 MeV photons. The mass energy absorption coefficients were calculated for 0.5 to 40 mean free paths of photons. In the energy region important for dental radiology the Zeff for all studied biomaterials are larger in comparison to larger energies. In x-rays for dental radiology and the energy absorption buildup factors are low, however CbMDI bio material shows a resonance at 80 keV. (Author)

  12. Vitamin B12 Deficiency in Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Carlos Tavares Bello

    2017-10-01

    Conclusion: Further studies are needed to identify the risk factors for the B12 deficit. The recognition of these variables will contribute to optimize the screening and prevention of the B12 deficiency in type 2 diabetes mellitus.

  13. 21 CFR 184.1945 - Vitamin B12.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vitamin B12. 184.1945 Section 184.1945 Food and... Substances Affirmed as GRAS § 184.1945 Vitamin B12. (a) Vitamin B12, also known as cyanocobalamin (C63H88Co... is used in food at levels not to exceed current good manufacturing practice. Vitamin B12 also may be...

  14. Simultaneous radioassay of folate and vitamin B12

    International Nuclear Information System (INIS)

    1981-01-01

    An improved simultaneous radioassay for folate and vitamin B 12 in biological specimens is described. A sample containing folate and vitamin B 12 is contacted with 125 I-folate and 57 Co-vitamin B 12 and their respective specific binders. After separation of the bound and free portions, the radioactivity in the portions is counted and the amounts of folate and vitamin B 12 then determined from standard curves. (U.K.)

  15. Degradation of vitamin B12 in dietary supplements.

    Science.gov (United States)

    Yamada, Keiko; Shimodaira, Michiko; Chida, Seiko; Yamada, Noriko; Matsushima, Norio; Fukuda, Morimichi; Yamada, Shoji

    2008-01-01

    Beverages and solid dietary supplements rich in various added vitamins and minerals have recently become available. It seems reasonable to consider that the intake of these foods is convenient for easy ingestion of nutrients, but problems caused by blending different nutrients in high concentrations have arisen. We focused on vitamin B12 (B12) among vitamins and determined the B12 contents of beverages and solid dietary supplements purchased from a retail shop. The B12 contents of three of five beverages were less than stated on the labels. On the other hand, certain beverages unexpectedly contained much more B12 than stated on the labels. In these beverages the amount of B12 decreased rapidly with time, whereas B12 content was lower than stated on the label in only one of four solid dietary supplements. The content of B12 was affected by storage time, light exposure, temperature and vitamin C. From experimental analysis with a competitive binding assay method employing a ACS Chemiluminescent B12 kit, examining differential binding by intrinsic factors and spectral analysis of B12, it was determined that some of the B12 might have been converted into B12 analogues or small degradation products by multinutrient interaction during storage.

  16. 21 CFR 582.5945 - Vitamin B12.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Vitamin B12. 582.5945 Section 582.5945 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5945 Vitamin B12. (a) Product. Vitamin B12. (b) Conditions of use. This substance is...

  17. Production Of Vitamin B 12 By Streptomyces Fulvissimus | Atta ...

    African Journals Online (AJOL)

    Fifty five of actinomycete isolates were screened for vitamin B12 production by growing on soybean meal medium fortified with cobalt. Only one AZ-Z-88 among nine actinomycete cultures was found to produce significantly higher yield of the vitamin B12 (64.57 ug/ml). Determination of vitamin B12 production was carried out ...

  18. In Silico Modeling of Gastrointestinal Drug Absorption: Predictive Performance of Three Physiologically Based Absorption Models.

    Science.gov (United States)

    Sjögren, Erik; Thörn, Helena; Tannergren, Christer

    2016-06-06

    Gastrointestinal (GI) drug absorption is a complex process determined by formulation, physicochemical and biopharmaceutical factors, and GI physiology. Physiologically based in silico absorption models have emerged as a widely used and promising supplement to traditional in vitro assays and preclinical in vivo studies. However, there remains a lack of comparative studies between different models. The aim of this study was to explore the strengths and limitations of the in silico absorption models Simcyp 13.1, GastroPlus 8.0, and GI-Sim 4.1, with respect to their performance in predicting human intestinal drug absorption. This was achieved by adopting an a priori modeling approach and using well-defined input data for 12 drugs associated with incomplete GI absorption and related challenges in predicting the extent of absorption. This approach better mimics the real situation during formulation development where predictive in silico models would be beneficial. Plasma concentration-time profiles for 44 oral drug administrations were calculated by convolution of model-predicted absorption-time profiles and reported pharmacokinetic parameters. Model performance was evaluated by comparing the predicted plasma concentration-time profiles, Cmax, tmax, and exposure (AUC) with observations from clinical studies. The overall prediction accuracies for AUC, given as the absolute average fold error (AAFE) values, were 2.2, 1.6, and 1.3 for Simcyp, GastroPlus, and GI-Sim, respectively. The corresponding AAFE values for Cmax were 2.2, 1.6, and 1.3, respectively, and those for tmax were 1.7, 1.5, and 1.4, respectively. Simcyp was associated with underprediction of AUC and Cmax; the accuracy decreased with decreasing predicted fabs. A tendency for underprediction was also observed for GastroPlus, but there was no correlation with predicted fabs. There were no obvious trends for over- or underprediction for GI-Sim. The models performed similarly in capturing dependencies on dose and

  19. Simultaneous radioassay of folate and vitamin B12

    International Nuclear Information System (INIS)

    Gutcho, S.; Mansbach, L.

    1979-01-01

    A serum sample is heated at an alkaline pH to release folate and vitamin B 12 from endogenous binders. A simultaneous radioassay for folate and vitamin B 12 is effected by contacting the sample with binder for folate, binder for vitamin B 12 , folote labeled with one radioactive isotope and vitamin B 12 labeled with another radioacitve isotope, followed by separation of bound and free portions, and determination of the radioactivity of at least one of the portions. The amounts of folate and vitamin B 12 present in the sample may be determined from standard curves

  20. Absorption studies

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Absorption studies were once quite popular but hardly anyone does them these days. It is easier to estimate the blood level of the nutrient directly by radioimmunoassay (RIA). However, the information obtained by estimating the blood levels of the nutrients is not the same that can be obtained from the absorption studies. Absorption studies are primarily done to find out whether some of the essential nutrients are absorbed from the gut or not and if they are absorbed, to determine how much is being absorbed. In the advanced countries, these tests were mostly done to detect pernicious anaemia where vitamin B 12 is not absorbed because of the lack of the intrinsic factor in the stomach. In the tropical countries, ''malabsorption syndrome'' is quire common. In this condition, several nutrients like fat, folic acid and vitamin B 12 are not absorbed. It is possible to study absorption of these nutrients by radioisotopic absorption studies

  1. Vitamin B12 assays compared by use of patients sera with low vitamin B12 content

    International Nuclear Information System (INIS)

    Sheridan, B.L.; Pearce, L.C.

    1985-01-01

    The authors compared four radioisotope dilution (RD) methods and a microbiological assay for measuring concentrations of vitamin B12 in a selected panel of serum samples from patients known to be deficient in the vitamin. Low (less than 100 ng/L) and borderline (100-180 ng/L) results were similar between methods, but use of the manufacturers recommended ranges for borderline results would have changed the diagnostic classifications for 22 of 38 samples. Results of all the RD methods inter-correlated well, but less so with the microbiological assay. Borderline, nondiagnostic results were common to all methods, and no apparent advantage was gained from using the microbiological assay

  2. Vitamin B12 Deficiency in Relation to Functional Disabilities

    Directory of Open Access Journals (Sweden)

    Heather E. Rasmussen

    2013-11-01

    Full Text Available This study was designed to assess whether symptoms, functional measures, and reported disabilities were associated with vitamin B12 (B12 deficiency when defined in three ways. Participants, aged 60 or more years of age, in 1999–2002 National Health and Nutrition Examination Surveys (NHANES were categorized in relation to three previously used definitions of B12 deficiency: (1 serum B12 20 μmol/L; and (3 serum B12 0.21 μmol/L. Functional measures of peripheral neuropathy, balance, cognitive function, gait speed, along with self-reported disability (including activities of daily living were examined with standardized instruments by trained NHANES interviewers and technicians. Individuals identified as B12 deficient by definition 2 were more likely to manifest peripheral neuropathy OR (odds (95% confidence intervals, p value: 9.70 (2.24, 42.07, 0.004 and report greater total disability, 19.61 (6.22, 61.86 0.0001 after adjustments for age, sex, race, serum creatinine, and ferritin concentrations, smoking, diabetes, and peripheral artery disease. Smaller, but significantly increased, odds of peripheral neuropathy and total disability were also observed when definition 3 was applied. Functional measures and reported disabilities were associated with B12 deficiency definitions that include B12 biomarkers (homocysteine or methylmalonic acid. Further study of these definitions is needed to alert clinicians of possible subclinical B12 deficiency because functional decline amongst older adults may be correctable if the individual is B12 replete.

  3. The Folate-Vitamin B12 Interaction, Low Hemoglobin, and the Mortality Risk from Alzheimer's Disease.

    Science.gov (United States)

    Min, Jin-Young; Min, Kyoung-Bok

    2016-03-21

    Abnormal hemoglobin levels are a risk factor for Alzheimer's disease (AD). Although the mechanism underlying these associations is elusive, inadequate micronutrients, particularly folate and vitamin B12, may increase the risk for anemia, cognitive impairment, and AD. In this study, we investigated whether the nutritional status of folate and vitamin B12 is involved in the association between low hemoglobin levels and the risk of AD mortality. Data were obtained from the 1999-2006 National Health and Nutrition Examination Survey (NHANES) and the NHANES (1999-2006) Linked Mortality File. A total of 4,688 participants aged ≥60 years with available baseline data were included in this study. We categorized three groups based on the quartiles of folate and vitamin B12 as follows: Group I (low folate and vitamin B12); Group II (high folate and low vitamin B12 or low folate and high vitamin B12); and Group III (high folate and vitamin B12). Of 4,688 participants, 49 subjects died due to AD. After adjusting for age, sex, ethnicity, education, smoking history, body mass index, the presence of diabetes or hypertension, and dietary intake of iron, significant increases in the AD mortality were observed in Quartile1 for hemoglobin (HR: 8.4, 95% CI: 1.4-50.8), and the overall risk of AD mortality was significantly reduced with increases in the quartile of hemoglobin (p for trend = 0.0200), in subjects with low levels of both folate and vitamin B12 at baseline. This association did not exist in subjects with at least one high level of folate and vitamin B12. Our finding shows the relationship between folate and vitamin B12 levels with respect to the association between hemoglobin levels and AD mortality.

  4. Vitamin B12 intake and status and cognitive function in elderly people.

    Science.gov (United States)

    Doets, Esmée L; van Wijngaarden, Janneke P; Szczecińska, Anna; Dullemeijer, Carla; Souverein, Olga W; Dhonukshe-Rutten, Rosalie A M; Cavelaars, Adrienne E J M; van 't Veer, Pieter; Brzozowska, Anna; de Groot, Lisette C P G M

    2013-01-01

    Current recommendations on vitamin B12 intake vary from 1.4 to 3.0 μg per day and are based on the amount needed for maintenance of hematologic status or on the amount needed to compensate obligatory losses. This systematic review evaluates whether the relation between vitamin B12 intake and cognitive function should be considered for underpinning vitamin B12 recommendations in the future. The authors summarized dose-response evidence from randomized controlled trials and prospective cohort studies on the relation of vitamin B12 intake and status with cognitive function in adults and elderly people. Two randomized controlled trials and 6 cohort studies showed no association or inconsistent associations between vitamin B12 intake and cognitive function. Random-effects meta-analysis showed that serum/plasma vitamin B12 (50 pmol/L) was not associated with risk of dementia (4 cohort studies), global cognition z scores (4 cohort studies), or memory z scores (4 cohort studies). Although dose-response evidence on sensitive markers of vitamin B12 status (methylmalonic acid and holotranscobalamin) was scarce, 4 of 5 cohort studies reported significant associations with risk of dementia, Alzheimer's disease, or global cognition. Current evidence on the relation between vitamin B12 intake or status and cognitive function is not sufficient for consideration in the development of vitamin B12 recommendations. Further studies should consider the selection of sensitive markers of vitamin B12 status. © The Author 2012. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. and Three-Photon Absorption Properties of PRODAN based chemo ...

    Indian Academy of Sciences (India)

    Mehboob

    Solvent dependent One-, Two- and Three-Photon Absorption. Properties of PRODAN based chemo-sensors. Md. Mehboob Alam, Mausumi Chattopadhyaya. Department of Chemistry, University of Calcutta, 92 A.P.C. Road, Kolkata - 700009,. India. CONTENTS. 1) Optimized coordinates of all the systems in Gas phase and ...

  6. Lhermitte's sign and vitamin B12 deficiency: case report

    OpenAIRE

    Teive, Hélio Afonso Ghizoni; Haratz, Salo; Zavala, Jorge; Munhoz, Renato Puppi; Scola, Rosana Hermínia; Werneck, Lineu César

    2009-01-01

    CONTEXT AND OBJECTIVE: Lhermitte's sign, a classical neurological sign, is a rare manifestation of vitamin B12 deficiency. The aim here was to report on a case of an elderly patient with vitamin B12 deficiency whose first clinical manifestation was the presence of Lhermitte's sign. CASE REPORT: We describe an elderly patient with vitamin B12 deficiency who presented cognitive dysfunction, peripheral polyneuropathy and sensory ataxia, and whose first clinical manifestation was the presence of ...

  7. Racial difference in serum Vitamin B12 levels

    International Nuclear Information System (INIS)

    Kwee, H.G.; Bowman, H.S.; Wells, L.W.

    1985-01-01

    Measurements of the serum Vitamin B 12 concentrations of 49 black and 49 white healthy adults demonstrate a significantly higher mean serum Vitamin B 12 level in blacks when compared to whites. The reason for this difference appears to be genetic, although environmental factors may also be involved. It is suggested that clinical laboratories should establish their own separate reference values of serum Vitamin B 12 for blacks and whites in order to prevent misinterpretation of test results

  8. Iron, folacin, vitamin B12 and zinc status and immune response in the elderly

    International Nuclear Information System (INIS)

    Henry-Christian, J.R.; Johnson, A.A.; Walters, C.S.; Greene, E.J.; Lindsey, A.A.

    1986-01-01

    The relationships of iron, folacin, vitamin B 12 and zinc status to cell-mediated immune response were investigated among 125 healthy, elderly persons (60-87 years of age). Plasma ferritin, plasma and red cell folate, and plasma vitamin B 12 levels were assayed immuno-radiometrically. Plasma and hair zinc levels were determined by atomic absorption spectroscopy. Immune response was determined by transformation of peripheral blood lymphocytes after stimulation with phytohemagglutinin (PHA) and concanavalin A (con A), and in mixed lymphocyte reaction. Deficiencies of iron, folacin vitamin B 12 and zinc were each associated (independently) with significantly lower lymphocyte responses to PHA and con A, and mixed lymphocyte reaction (P 12 or zinc. Further, they suggest that deficiencies of these nutrients may play a role in the depression of cell-mediated immunity with age, which in turn may lead to increased susceptibility to infectious diseases and cancer in the elderly

  9. Voltammetry of Vitamin B12 on a thin self-assembled monolayer modified electrode

    International Nuclear Information System (INIS)

    Yang Nianjun; Wan Qijin; Wang, Xiaoxia

    2005-01-01

    Vitamin B 12 showed three reduction waves at a thin self-assembled monolayer of mercaptoacetic acid modified gold electrode at 0.21, 0.16, -0.41 V in a 0.01 mol l -1 HCl solution at a scan rate of 100 mV s -1 . The overall electrode reaction followed an ECE mechanism, leading to a total two-electron exchange. The predominant Co(III) form was reduced directly at 0.21 V by a one-electron transfer accomplished by CN - cleavage into the cyanocob(II)alamin. The latter species then equilibrated with the base-off B 12r , which was immediately reduced into B 12s at 0.16 V. The wave at -0.41 V might be a catalytic hydrogen wave. The cathodic peak currents at 0.21 V were controlled by the diffusion of Vitamin B 12 . On the base of its diffusion behavior, the semi-derivate voltammetric method for the detection of Vitamin B 12 was presented. The semi-derivate voltammetric peak current of the wave at 0.21 V was linear with the content of Vitamin B 12 in the range of 4.0 x 10 -9 to 4.0 x 10 -5 mol l -1 . The detection limit was 1.0 x 10 -9 mol l -1 . The proposed method was applied successfully to determine the content of Vitamin B 12 in pharmaceutical preparations

  10. Terahertz gas sensor based on absorption-induced transparency

    Directory of Open Access Journals (Sweden)

    Rodrigo Sergio G.

    2016-01-01

    Full Text Available A system for the detection of spectral signatures of gases at the Terahertz regime is presented. The system consists in an initially opaque holey metal film whereby the introduction of a gas provokes the appearance of spectral features in transmission and reflection, due to the phenomenom of absorption-induced transparency (AIT. The peaks in transmission and dips in reflection observed in AIT occur close to the absorption energies of the molecules, hence its name. The presence of the gas would be thus revealed as a strong drop in reflectivity measurements at one (or several of the gas absorption resonances. As a proof of principle, we theoretically demonstrate how the AIT-based sensor would serve to detect tiny amounts of hydrocyanic acid.

  11. Prevalence of Vitamin B12 and Folate Deficiencies and ...

    African Journals Online (AJOL)

    ... 2Faculty of Dentistry, International Branch, 3Department of Internal Medicine & Endocrine and ... Keywords: Vitamin B12 deficiency, Folate deficiency, Homocysteinemia, Elderly population ... gastritis, intestinal malabsorption, pancreatic.

  12. Folic acid fortification: why not vitamin B12 also?

    Science.gov (United States)

    Selhub, Jacob; Paul, Ligi

    2011-01-01

    Folic acid fortification of cereal grains was introduced in many countries to prevent neural tube defect occurrence. The metabolism of folic acid and vitamin B12 intersect during the transfer of the methyl group from 5-methyltetrahydrofolate to homocysteine catalyzed by B12-dependent methioine synthase. Regeneration of tetrahydrofolate via this reaction makes it available for synthesis of nucleotide precursors. Thus either folate or vitamin B12 deficiency can result in impaired cell division and anemia. Exposure to extra folic acid through fortification may be detrimental to those with vitamin B12 deficiency. Among participants of National Health And Nutrition Examination Survey with low vitamin B12 status, high serum folate (>59 nmol/L) was associated with higher prevalence of anemia and cognitive impairment when compared with normal serum folate. We also observed an increase in the plasma concentrations of total homocysteine and methylmalonic acid (MMA), two functional indicators of vitamin B12 status, with increase in plasma folate under low vitamin B12 status. These data strongly imply that high plasma folate is associated with the exacerbation of both the biochemical and clinical status of vitamin B12 deficiency. Hence any food fortification policy that includes folic acid should also include vitamin B12. Copyright © 2011 International Union of Biochemistry and Molecular Biology, Inc.

  13. Electron addition to alkyl cobalamins, coenzyme B12 and vitamin B12

    International Nuclear Information System (INIS)

    Rao, D.N.R.; Symons, M.C.R.

    1983-01-01

    Exposure of dilute solutions of methyl and ethyl cobalamins and coenzyme B 12 in dilute solutions (D 2 O+CD 3 OD) to 60 Co #betta#-rays at 77 K gave a single broad feature in the free-spin region assigned to electron-capture species with the excess electron largely confined to a π* corrin orbital. On warming above 77 K the methyl derivative gave a novel species with spectral features characteristic of an unpaired electron in the Co(dsub(x 2 -y 2 )) orbital. The other two substrates gave spectra due to Cosup(II)Bsub(12r) both on warming and after photolyses with visible light. The acetyl derivative gave an electron-capture species whose e.s.r. spectrum was characteristic of an electron in the Co(dsub(z 2 )) orbital, which on warming above 77 K changed to the normal Cosup(II)Bsub(12r) spectrum. The cyano derivative (vitamin B 12 ) gave electron addition into the Co(dsub(z 2 )) orbital, as evidenced by the large hyperfine coupling to 13 C from 13 CN ligands. On annealing, cyanide ions were lost irreversibly, Bsub(12r) being detected by e.s.r. spectroscopy. In contrast, the dicyano derivative on electron addition at 77 K gave a species containing only one 13 CN ligand. Hence in this case one CN - ligand was lost at 77 K, with no return of the dimethylbenzimidazole ligand. These results are discussed in terms of a new mechanism for electron-addition to alkyl cobalamins. (author)

  14. The Relationship of Vitamin B12 Deficiency and Red Cell Distribution Width-Platelet Ratio

    Directory of Open Access Journals (Sweden)

    Nigar Yilmaz

    2016-09-01

    Full Text Available Objective: We aimed to investigate the relationship between vitamin B12 deficiency and red cell distribution widthplatelet ratio (RPR, and the variations in the parameters on vitamin B12 treatment. Methods: One hundred fifty-four patients with untreated vitamin B12 deficiency (56% men, mean age: 50 ± 12.7 years (untreated group, 86 patients with vitamin B12 deficiency (62% men, mean age: 42 ± 20.7 years on vitamin B12 treatment (treated group, and 92 age- and sex-matched control group (54% men, mean age: 45 ± 15.1 years were included in the study. Hematological parameters were evaluated by the method of laser-based flow cytometric impedance, using an automated blood cell counter (ABX Pentra 120 Hematology Blood Analyzer. Results: RPR was significantly reduced in treated group compared with untreated group (4.88 ± 1.06; 6.13 ± 1.27; p0.05. Conclusion: We proposed that vitamin B12 deficiency has effects on RPR and supplementation with vitamin B12 corrects the RPR levels. J Clin Exp Invest 2016; 7 (3: 211-215

  15. A general review on vitamin B12 deficiency with focus on the situation in Jordan

    International Nuclear Information System (INIS)

    Qutob, M. S.; Takruri, H. R.

    2011-01-01

    Vitamin B 12 (cobalamin) is an essential nutrient that is only obtained from foods of animal origin, such as meat, eggs and dairy products. Vitamin B 12 plays an important role in DNA synthesis and neurological function. Thus its deficiency can lead to several neurological symptoms such as memory loss, dizziness and in severe cases may lead to dementia. Many factors can cause or lead to vitamin B-1 2 deficiency. Among these are malabsorption, several gastron intestinal problems (i.e. celiac disease, Crobn's disease) and gastrointestinal surgeries. diagnosis of vitamin B-1 2 status depends commonly on serum vitamin B 12 which is nonspecific tool for the deficiency. Other more specific tests, which reflect true deficiency, include serum and urine methylmalonic aci de, total serum homocysteine and serum holotranscobalamin. Vitamin B 12 deficiency is a worldwide public health problem; epidemiological studies showed that its prevalence in industrialized countries ranges from 5-60% of the population depending on the used cutoff point of cobalamin level. In Jordan, many reports were published on vitamin B 12 deficiency. However, these reports gave different results of its prevalence ranging from 16-48% depending on the serum vitamin B 12 cutoff point used. A recent study showed a prevalence of true deficiency of 32.7% based on measuring both serum vitamin B 12 level and plasma methylmalonic acid. (authors).

  16. Gastric emptying in patients with vitamin B12 deficiency

    International Nuclear Information System (INIS)

    Yagci, Muenci; Yamac, Kadri; Acar, Kadir; Haznedar, Rauf; Cingi, Elif; Kitapci, Mehmet

    2002-01-01

    The clinical presentation of patients with vitamin B 12 deficiency varies in a spectrum ranging from haematological disorders to neuropsychiatric diseases. In rare cases, orthostatic hypotension, impotence, constipation and urinary retention have been attributed to autonomic nervous system dysfunction due to vitamin B 12 deficiency. The aim of this study was to evaluate the effect of vitamin B 12 deficiency on autonomic nervous system function by studying gastric emptying times (T 1/2 ). Twenty patients with newly diagnosed vitamin B 12 deficiency and 12 control patients with gastritis and normal vitamin B 12 levels were enrolled in this study. Gastroduodenoscopy, endoscopic biopsy, histopathological evaluation of the biopsy specimens and radionuclide gastric emptying studies were performed. After vitamin B 12 replacement therapy for 3 months, radionuclide gastric emptying studies were repeated. Mean gastric emptying T 1/2 in patients before and after treatment and in controls were 103.83±48.80 min, 90.00±17.29 min and 74.55±8.52 min, respectively. The difference in mean gastric emptying T 1/2 between patients before treatment and controls was statistically significant (P 12 treatment (P 1/2 was somewhat shorter. There were no positive or negative correlations between gastric emptying T 1/2 and the following parameters: haemoglobin, vitamin B 12 level and Helicobacter pylori positivity. In conclusion, gastric emptying T 1/2 was prolonged in patients with vitamin B 12 deficiency and this prolongation was not corrected after vitamin B 12 replacement therapy. Although autonomic nervous system dysfunction due to vitamin B 12 deficiency rarely gives rise to clinical manifestations, latent dysfunction demonstrated by laboratory tests seems to be a frequent phenomenon. The level of vitamin B 12 does not correlate with the degree of autonomic nervous system dysfunction measured by radionuclide gastric emptying studies. (orig.)

  17. Physiologically Based Pharmacokinetic and Absorption Modeling for Osmotic Pump Products.

    Science.gov (United States)

    Ni, Zhanglin; Talattof, Arjang; Fan, Jianghong; Tsakalozou, Eleftheria; Sharan, Satish; Sun, Dajun; Wen, Hong; Zhao, Liang; Zhang, Xinyuan

    2017-07-01

    Physiologically based pharmacokinetic (PBPK) and absorption modeling approaches were employed for oral extended-release (ER) drug products based on an osmotic drug delivery system (osmotic pumps). The purpose was to systemically evaluate the in vivo relevance of in vitro dissolution for this type of formulation. As expected, in vitro dissolution appeared to be generally predictive of in vivo PK profiles, because of the unique feature of this delivery system that the in vitro and in vivo release of osmotic pump drug products is less susceptible to surrounding environment in the gastrointestinal (GI) tract such as pH, hydrodynamic, and food effects. The present study considered BCS (Biopharmaceutics Classification System) class 1, 2, and 3 drug products with half-lives ranging from 2 to greater than 24 h. In some cases, the colonic absorption models needed to be adjusted to account for absorption in the colon. C max (maximum plasma concentration) and AUCt (area under the concentration curve) of the studied drug products were sensitive to changes in colon permeability and segmental GI transit times in a drug product-dependent manner. While improvement of the methodology is still warranted for more precise prediction (e.g., colonic absorption and dynamic movement in the GI tract), the results from the present study further emphasized the advantage of using PBPK modeling in addressing product-specific questions arising from regulatory review and drug development.

  18. Radioisotope binding capacity of serum for folic acid, vitamin B12 and ferritin in hematologic and rheumatologic patients

    International Nuclear Information System (INIS)

    Ringelhann, B.; Revicky, A.; Arvai, I.; Megyeri, A.; Goemoer, B.; Josfay, L.; Csak, E.

    1980-01-01

    Folic acid, vitamin B 12 and ferritin levels were determined by radioimmunoassay in patients suffering from hemic and rheumatic diseases, resp. Compared to the controls the folic acid levels were lower in some cases, the deficiency of folic acid absorption and distribution possibly being caused by the disease. Vitamin B 12 was only slightly decreased. In ankylosing spondylitis the transferrin level was similar to that of the controls, but in rheumatoid arthritis and in patients suffering from various diseases it was increased

  19. Influence of vitamin b-12 complex injection (eldervit-12) on ...

    African Journals Online (AJOL)

    Objectives: To assess the effect of vitamin B-12 complex injection on the nephrotoxicity of gentamicin. Design: Experimental study using a pre-validated model. Subject: Adult Swiss albino rats weighing 140-214g, Generic gentamicin sulphate injection and Vitamin B-12complex injection containing 2500mcg ...

  20. Vitamin b 12 supplementation: effects on some biochemical and ...

    African Journals Online (AJOL)

    Phenytoin is known to have some toxicological implications. Vitamin B12 supplementation during phenytoin administration was investigated to assess the benefits and risks of single vitamin supplementation. This study evaluated the biochemical and haematological effects of vitamin B12 on phenytoin toxicity. Twenty-four ...

  1. Vegan Diet, Subnormal Vitamin B-12 Status and Cardiovascular Health

    Directory of Open Access Journals (Sweden)

    Kam S. Woo

    2014-08-01

    Full Text Available Vegetarian diets have been associated with atherosclerosis protection, with healthier atherosclerosis risk profiles, as well as lower prevalence of, and mortality from, ischemic heart disease and stroke. However, there are few data concerning the possible cardiovascular effects of a vegan diet (with no meat, dairy or egg products. Vitamin B-12 deficiency is highly prevalent in vegetarians; this can be partially alleviated by taking dairy/egg products in lact-ovo-vegetarians. However, metabolic vitamin B-12 deficiency is highly prevalent in vegetarians in Australia, Germany, Italy and Austria, and in vegans (80% in Hong Kong and India, where vegans rarely take vitamin B-12 fortified food or vitamin B-12 supplements. Similar deficiencies exist in northern Chinese rural communities consuming inadequate meat, egg or dairy products due to poverty or dietary habits. Vascular studies have demonstrated impaired arterial endothelial function and increased carotid intima-media thickness as atherosclerosis surrogates in such metabolic vitamin B-12 deficient populations, but not in lactovegetarians in China. Vitamin B-12 supplementation has a favourable impact on these vascular surrogates in Hong Kong vegans and in underprivileged communities in northern rural China. Regular monitoring of vitamin B-12 status is thus potentially beneficial for early detection and treatment of metabolic vitamin B-12 deficiency in vegans, and possibly for prevention of atherosclerosis-related diseases.

  2. Vegan diet, subnormal vitamin B-12 status and cardiovascular health.

    Science.gov (United States)

    Woo, Kam S; Kwok, Timothy C Y; Celermajer, David S

    2014-08-19

    Vegetarian diets have been associated with atherosclerosis protection, with healthier atherosclerosis risk profiles, as well as lower prevalence of, and mortality from, ischemic heart disease and stroke. However, there are few data concerning the possible cardiovascular effects of a vegan diet (with no meat, dairy or egg products). Vitamin B-12 deficiency is highly prevalent in vegetarians; this can be partially alleviated by taking dairy/egg products in lact-ovo-vegetarians. However, metabolic vitamin B-12 deficiency is highly prevalent in vegetarians in Australia, Germany, Italy and Austria, and in vegans (80%) in Hong Kong and India, where vegans rarely take vitamin B-12 fortified food or vitamin B-12 supplements. Similar deficiencies exist in northern Chinese rural communities consuming inadequate meat, egg or dairy products due to poverty or dietary habits. Vascular studies have demonstrated impaired arterial endothelial function and increased carotid intima-media thickness as atherosclerosis surrogates in such metabolic vitamin B-12 deficient populations, but not in lactovegetarians in China. Vitamin B-12 supplementation has a favourable impact on these vascular surrogates in Hong Kong vegans and in underprivileged communities in northern rural China. Regular monitoring of vitamin B-12 status is thus potentially beneficial for early detection and treatment of metabolic vitamin B-12 deficiency in vegans, and possibly for prevention of atherosclerosis-related diseases.

  3. Hampered Vitamin B12 Metabolism in Gaucher Disease?

    Directory of Open Access Journals (Sweden)

    Luciana Hannibal PhD

    2017-02-01

    Full Text Available Untreated vitamin B 12 deficiency manifests clinically with hematological abnormalities and combined degeneration of the spinal cord and polyneuropathy and biochemically with elevated homocysteine (Hcy and methylmalonic acid (MMA. Vitamin B 12 metabolism involves various cellular compartments including the lysosome, and a disruption in the lysosomal and endocytic pathways induces functional deficiency of this micronutrient. Gaucher disease (GD is characterized by dysfunctional lysosomal metabolism brought about by mutations in the enzyme beta-glucocerebrosidase (Online Mendelian Inheritance in Man (OMIM: 606463; Enzyme Commission (EC 3.2.1.45, gene: GBA1 . In this study, we collected and examined available literature on the associations between GD, the second most prevalent lysosomal storage disorder in humans, and hampered vitamin B 12 metabolism. Results from independent cohorts of patients show elevated circulating holotranscobalamin without changes in vitamin B 12 levels in serum. Gaucher disease patients under enzyme replacement therapy present normal levels of Hcy and MMA. Although within the normal range, a significant increase in Hcy and MMA with normal serum vitamin B 12 was documented in treated GD patients with polyneuropathy versus treated GD patients without polyneuropathy. Thus, a functional deficiency of vitamin B 12 caused by disrupted lysosomal metabolism in GD is a plausible mechanism, contributing to the neurological form of the disorder but this awaits confirmation. Observational studies suggest that an assessment of vitamin B 12 status prior to the initiation of enzyme replacement therapy may shed light on the role of vitamin B 12 in the pathogenesis and progression of GD.

  4. The impact of vegan diet on B-12 status in healthy omnivores: five-year prospective study.

    Science.gov (United States)

    Mądry, Edyta; Lisowska, Aleksandra; Grebowiec, Philip; Walkowiak, Jarosław

    2012-04-02

    There are no long-term prospective studies assessing the impact of the vegan diet on vitamin B-12 (B-12) status. Many vegans take B-12 supplements irregularly or refuse to adopt them at all, considering them to be "unnatural" products. The use of B-12 fortified food may be an alternative. Therefore, we aimed to estimate the long-term effect of a vegan diet on serum B-12 concentrations in healthy omnivore adults, comparing the influence of natural products consumption and B-12 fortified food. A five year prospective study was carried out comprising 20 omnivore healthy adult subjects, who moved to strict vegan diet for 5 years. Ten volunteers followed vegan diet based entirely on natural products, while the remaining ten subjects consumed food fortified in B-12. In all subjects serum vitamin B-12 concentration was determined before and 6, 12, 24 and 60 months after the implementation of the diet. A significant decrease (p vegan diet. However, observed changes were in fact limited to the subgroup consuming exclusively natural products (p vegan diet is associated with the risk of vitamin B-12 deficiency. B-12 fortified products might constitute a valuable alternative in vegans refusing to take vitamin supplements.

  5. Stability and aromaticity of nH2@B12N12 (n=1–12 clusters

    Directory of Open Access Journals (Sweden)

    Pratim K. Chattaraj

    2011-04-01

    Full Text Available Standard ab initio and density functional calculations are carried out to determine the structure, stability, and reactivity of B12N12 clusters with hydrogen doping. To lend additional support, conceptual DFT-based reactivity descriptors and the associated electronic structure principles are also used. Related cage aromaticity of this B12N12 and nH2@B12N12 are analyzed through the nucleus independent chemical shift values.

  6. Vitamin B-12 and Depression: Are They Related?

    Science.gov (United States)

    ... al. Nutritional aspects of depression. Cellular Physiology and Biochemistry. 2015;37:1029. Vitamin B12. Natural Medicines. https:// ... Clinic logo are trademarks of Mayo Foundation for Medical Education and Research. © 1998-2018 Mayo Foundation for ...

  7. Vitamin B12 deficiency: Characterization of psychometrics and MRI morphometrics.

    Science.gov (United States)

    Hsu, Yen-Hsuan; Huang, Ching-Feng; Lo, Chung-Ping; Wang, Tzu-Lan; Tu, Min-Chien

    2016-01-01

    Vitamin B12 is essential for the integrity of the central nervous system. However, performances in different cognitive domains relevant to vitamin B12 deficiency remain to be detailed. To date, there have been limited studies that examined the relationships between cognitions and structural neuroimaging in a single cohort of low-vitamin B12 status. The present study aimed to depict psychometrics and magnetic resonance imaging (MRI) morphometrics among patients with vitamin B12 deficiency, and to examine their inter-relations. We compared 34 consecutive patients with vitamin B12 deficiency (serum level ≤ 250 pg/ml) to 34 demographically matched controls by their cognitive performances and morphometric indices of brain MRI. The correlations between psychometrics and morphometrics were analyzed. The vitamin B12 deficiency group had lower scores than the controls on total scores of Mini-Mental Status Examination (MMSE) and Cognitive Abilities Screening Instrument (CASI) (both P psychometric and morphometric indices, pronounced correlations between bicaudate ratio and long-term memory, mental manipulation, orientation, language, and verbal fluency were noted (all P < 0.01). Vitamin B12 deficiency is associated with a global cognition decline with language, orientation, and mental manipulation selectively impaired. Preferential atrophy in frontal regions is the main neuroimaging feature. Although the frontal ratio highlights the relevant atrophy among patients, the bicaudate ratio might be the best index on the basis of its strong association with global cognition and related cognitive domains, implying dysfunction of fronto-subcortical circuits as the fundamental pathogenesis related to vitamin B12 deficiency.

  8. Malabsorption of vitamin B12 in homozygous β-thalassemia

    International Nuclear Information System (INIS)

    Vlachos, P.; Liakakos, D.

    1976-01-01

    Schilling tests were performed in ten children aged 5-12 years suffering from homozygous β-thalassemia. 57 Co labelled vitamin B 12 values excreted in the urine have been found much lower than normal and remained low when the same procedure was repeated with the addition of intrinsic factor. The possible factors responsible for this malabsorption of vitamin B 12 seemed to be liver damage and folic acid deficiency. (orig.) [de

  9. Synthesis and crystal structure of MgB12

    International Nuclear Information System (INIS)

    Adasch, Volker; Hess, Kai-Uwe; Ludwig, Thilo; Vojteer, Natascha; Hillebrecht, Harald

    2006-01-01

    Single crystals of MgB 12 were synthesized from the elements in a Mg/Cu melt at 1600deg. C. MgB 12 crystallizes orthorhombic in space group Pnma with a=16.632(3)A, b=17.803(4)A and c=10.396(2)A. The crystal structure (Z=30, 5796 reflections, 510 variables, R 1 (F)=0.049, wR 2 (I)=0.134) consists of a three dimensional net of B 12 icosahedra and B 21 units in a ratio 2:1. The B 21 units are observed for the first time in a solid compound. Mg is on positions with partial occupation. The summation reveals the composition MgB 12.35 or Mg 0.97 B 12 , respectively. This is in good agreement with the value of MgB 11.25 as expected by electronic reasons to stabilize the boron polyhedra B 12 2- and B 21 4-

  10. A triple isotope technique for estimation of fat and vitamin B12 malabsorption in Chrohn's disease

    International Nuclear Information System (INIS)

    Pedersen, N.T.; Rannem, T.

    1991-01-01

    A test for simultaneous estimation of vitamin B 12 and fat absorption from stool samples was investigated in 25 patients with severe diarrhoea after operation for Chrohn's disease. 51 CrCl 3 was ingested as a non-absorbable marker, 58 Co-cyanocobalamin as vitamin B 12 tracer, and 14 C-triolein as lipid tracer. Faeces were collected separately for three days. Some stool-to-stool variation in the 58 Co/ 51 Cr and 14 C/ 51 Cr ratios was seen. When the 58 Co-B 12 and 14 C-triolein excretion was estimated in samples of the two stools with the highest activities of 51 Cr, the variations of the estimates were less than ±10% and ±15% of the doses ingested, respectively. 12 of the 25 patients were not able to collect faeces and urine quantitatively and separately. However, in all patients faeces with sufficient radioactivity for simultaneous estimation of faecal 58 Co-B 12 and 14 C-triolein excretion from stool samples were obtained. 16 refs., 3 figs., 1 tab

  11. [Vitamin B12 Deficiency in Type 2 Diabetes Mellitus].

    Science.gov (United States)

    Tavares Bello, Carlos; Capitão, Ricardo Miguel; Sequeira Duarte, João; Azinheira, Jorge; Vasconcelos, Carlos

    2017-10-31

    Type 2 diabetes mellitus is a common disease, affecting up to 13.1% of the Portuguese population. In addition to the known micro and macrovascular complications, drug side effects constitute a major concern, leading to changes in the treatment guidelines, which favor safety over efficacy. Metformin is the first-line pharmacological treatment for most patients with type 2 diabetes mellitus; however, it has been associated with vitamin B12 deficiency in up to 30% of treated patients. The authors describe the prevalence of vitamin B12 deficiency in a diabetic population and explore the possible underlying factors. Retrospective, observational study. Clinical and laboratory data of type 2 diabetes mellitus patients whose vitamin B12 status was evaluated in the last decade (2005 - 2016) were analyzed. Patients with known malabsorptive syndromes or having undergone bariatric surgery were excluded from the study. Statistical analysis of the data was done and the results were considered statistically significant at p values 2.2 years and 11 ± 10.4 years of type 2 diabetes mellitus duration. These patients had a high prevalence of complications: diabetic renal disease 47.7%, neuropathy 9.2%, retinopathy 14.9%, coronary artery disease 8.4%, cerebrovascular disease 10.9%, and peripheral arterial disease 5.5%. Vitamin B12 deficiency (21.4% of the population and this subgroup was older (68.4 vs 65.8 years, p = 0.006), had a longer type 2 diabetes mellitus duration (13.35 vs 10.36 years; p = 0.001), higher prevalence of retinopathy (20.9% vs 13.3%; p = 0.005) and thyroid dysfunction (34% vs 23.7%; p = 0.002). Vitamin B12 deficiency was also more frequent in patients treated with metformin (24.7% vs 15.8%; p = 0.017), antiplatelet agents (25.4% vs 16.2%, p 26.8% vs 18.2%; p = 0.001). After adjustment for possible confounders, the variables associated with B12 deficiency were: metformin, hypothyroidism, age and type 2 diabetes mellitus duration. Despite the retrospective design

  12. β Absorption dust concentration monitor system based on the PLC

    International Nuclear Information System (INIS)

    Lian Dexing; Zhou Xiuliang; Liu Liyan; Li Zonglun; Cao Guanghui; Mao Wanchong

    2011-01-01

    To provide an on-line automatic system for dust concentration monitor is the purpose of this design.The system based on β-ray-absorption-method,employing PLC (Programmable Logic Controller) control technology, is presented. The user input parameter setup,the data acquisition and processing, and the communication with computer can be effectively regulated using the advanced PLC control technology. It has the features of high reliability, easy operation and easy maintenance, and the ability to monitor remotely. Measurement range: 0.1-1500 mg/m 3 , Accuracy: ±9%. The structure,working principle, electric circuit and software development of the system are introduced in detail. (authors)

  13. Vitamin B12 and folate deficiency in chronic heart failure.

    Science.gov (United States)

    van der Wal, Haye H; Comin-Colet, Josep; Klip, Ijsbrand T; Enjuanes, Cristina; Grote Beverborg, Niels; Voors, Adriaan A; Banasiak, Waldemar; van Veldhuisen, Dirk J; Bruguera, Jordi; Ponikowski, Piotr; Jankowska, Ewa A; van der Meer, Peter

    2015-02-01

    To determine the prevalence, clinical correlates and the effects on outcome of vitamin B12 and folic acid levels in patients with chronic heart failure (HF). We studied an international pooled cohort comprising 610 patients with chronic HF. The main outcome measure was all-cause mortality. Mean age of the patients was 68±12 years and median serum N-terminal prohormone brain natriuretic peptide level was 1801 pg/mL (IQR 705-4335). Thirteen per cent of the patients had an LVEF >45%. Vitamin B12 deficiency (serum level <200 pg/mL), folate deficiency (serum level <4.0 ng/mL) and iron deficiency (serum ferritin level <100 µg/L, or 100-299 µg/L with a transferrin saturation <20%) were present in 5%, 4% and 58% of the patients, respectively. No significant correlation between mean corpuscular volume and vitamin B12, folic acid or ferritin levels was observed. Lower folate levels were associated with an impaired health-related quality of life (p=0.029). During a median follow-up of 2.10 years (1.31-3.60 years), 254 subjects died. In multivariable proportional hazard models, vitamin B12 and folic acid levels were not associated with prognosis. Vitamin B12 and folate deficiency are relatively rare in patients with chronic HF. Since no significant association was observed between mean corpuscular volume and neither vitamin B12 nor folic acid levels, this cellular index should be used with caution in the differential diagnosis of anaemia in patients with chronic HF. In contrast to iron deficiency, vitamin B12 and folic acid levels were not related to prognosis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  14. Papel da vitamina B12 na patogenia da mielose funicular

    Directory of Open Access Journals (Sweden)

    Horacio M. Canelas

    1965-12-01

    Full Text Available Foi estudada a absorção da vitamina B12 radioativa em 29 casos de mielose funicular. O diagnóstico baseou-se na clássica sintomatologia neu- rológica e na presença de acloridria gástrica e eventuais alterações hemato-lógicas. As manifestações neurológicas foram avaliadas de modo semiquan-titativo e correlacionadas com os resultados do teste de excreção urinária da vitamina B12. Não foi verificada correlação significante da absorção da vitamina B12, quer com a sintomatologia nuerológica total, quer com as síndromes periférica e funicular dorsal. Contudo, foi encontrada significante correlação negativa entre a síndrome piramidal e a absorção da vitamina B12. Os resultados são confrontados com o papel desempenhado pela vitamina B12 na síntese das bainhas de mielina e do ácido ribonuclêico, sendo salientada a importância dêste último para a vida das células nervosas e dos longos axônios.

  15. All-optical reservoir computer based on saturation of absorption.

    Science.gov (United States)

    Dejonckheere, Antoine; Duport, François; Smerieri, Anteo; Fang, Li; Oudar, Jean-Louis; Haelterman, Marc; Massar, Serge

    2014-05-05

    Reservoir computing is a new bio-inspired computation paradigm. It exploits a dynamical system driven by a time-dependent input to carry out computation. For efficient information processing, only a few parameters of the reservoir needs to be tuned, which makes it a promising framework for hardware implementation. Recently, electronic, opto-electronic and all-optical experimental reservoir computers were reported. In those implementations, the nonlinear response of the reservoir is provided by active devices such as optoelectronic modulators or optical amplifiers. By contrast, we propose here the first reservoir computer based on a fully passive nonlinearity, namely the saturable absorption of a semiconductor mirror. Our experimental setup constitutes an important step towards the development of ultrafast low-consumption analog computers.

  16. Hyperspectral tomography based on multi-mode absorption spectroscopy (MUMAS)

    Science.gov (United States)

    Dai, Jinghang; O'Hagan, Seamus; Liu, Hecong; Cai, Weiwei; Ewart, Paul

    2017-10-01

    This paper demonstrates a hyperspectral tomographic technique that can recover the temperature and concentration field of gas flows based on multi-mode absorption spectroscopy (MUMAS). This method relies on the recently proposed concept of nonlinear tomography, which can take full advantage of the nonlinear dependency of MUMAS signals on temperature and enables 2D spatial resolution of MUMAS which is naturally a line-of-sight technique. The principles of MUMAS and nonlinear tomography, as well as the mathematical formulation of the inversion problem, are introduced. Proof-of-concept numerical demonstrations are presented using representative flame phantoms and assuming typical laser parameters. The results show that faithful reconstruction of temperature distribution is achievable when a signal-to-noise ratio of 20 is assumed. This method can potentially be extended to simultaneously reconstructing distributions of temperature and the concentration of multiple flame species.

  17. Evaluation of vitamin B 12 deficiency in various clinical condition

    International Nuclear Information System (INIS)

    Baig, J.A.; Alam, J.M.; Kazmi, T.; Waseem, S.; Hussain, A.; Arif, S.; Shaheen, R.; Sultana, I.

    2010-01-01

    Low levels of vitamin B 12 have been associated with several clinical conditions. However no single symptom or group of symptoms can be made responsible. Reported causes of deficiency among older population are hematologic or neurological, followed by gastrointestinal and possibly vascular symptoms. The present prospective observational study was, hence, initiated to evaluate the underlying clinical condition or symptoms associated with vitamin B12 deficiency. The study was prospective observational and carried out on 121 patients (males, n=63 and females, n=58) for the period from January 1, 2004 to January 24, 2007. Age ranges were between 16 - 70 years, and categorized as > 60 yrs and < 60 years. All blood parameters were analyzed by standardized methods on automated analyzers. The deficiency was found to be more prevalent in males and increased from 52.06% to 58.10% in individuals with vitamin B12 <150 pg/ml. Mal nourishment was noted among the most subjects and weakness and anemia were frequent clinical findings (35.55%, n=43, 14%, n=51). Other clinical conditions were neuropsychiatric. Whereas less frequent findings were paraesthesia and gastrointestinal symptoms. Hypertension was more prevalent in vitamin B12 deficient individuals followed by diabetes, dementia, stroke, ischemic heart disease and Parkinson's disease. (author)

  18. 32 CFR 806b.12 - Requesting the Social Security Number.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Requesting the Social Security Number. 806b.12... Number. When asking an individual for his or her Social Security Number, always give a Privacy Act... Social Security Number; and whether providing the Social Security Number is voluntary or mandatory. Do...

  19. Investigation of the binding affinity in vitamin B12-Bovine serum albumin system using various spectroscopic methods

    Science.gov (United States)

    Makarska-Bialokoz, Magdalena

    2017-09-01

    The binding affinity between vitamin B12 (VitB12) and bovine serum albumin (BSA) has been investigated in aqueous solution at pH = 7.4, employing UV-vis absorption and steady-state, synchronous and three-dimensional fluorescence spectra techniques. Representative effects noted for BSA intrinsic fluorescence resulting from the interactions with VitB12 confirm the formation of π-π stacked non-covalent and non-fluorescent complexes in the system VitB12-BSA. All the determined parameters, the binding, fluorescence quenching and bimolecular quenching rate constants (of the order of 104 L mol- 1, 103 L mol- 1 and 1011 L mol- 1 s- 1, respectively), as well as Förster resonance energy transfer parameters validate the mechanism of static quenching. The interaction with VitB12 induces folding of the polypeptide chains around Trp residues of BSA, resulting in a more hydrophobic surrounding. Presented outcomes suggest that the addition of VitB12 can lead to the more organized BSA conformation and its more folded tertiary structure, what could influence the physiological functions of bovine serum albumin, notably in case of its overuse or abnormal metabolism.

  20. Dietary sources of vitamin B-12 and their association with vitamin B-12 status markers in healthy older adults in the B-PROOF study

    NARCIS (Netherlands)

    Brouwer-Brolsma, E.M.; Dhonukshe-Rutten, R.A.M.; Wijngaarden, van J.P.; Zwaluw, van der N.L.; Velde, van der N.; Groot, de C.P.G.M.

    2015-01-01

    Low vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations between

  1. Dietary Sources of Vitamin B-12 and Their Association with Vitamin B-12 Status Markers in Healthy Older Adults in the B-PROOF Study

    NARCIS (Netherlands)

    Brouwer-Brolsma, Elske M.; Dhonukshe-Rutten, Rosalie A. M.; van Wijngaarden, Janneke P.; Zwaluw, Nikita L. van der; Velde, Nathalie van der; de Groot, Lisette C. P. G. M.

    2015-01-01

    Low vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations between

  2. Dietary sources of vitamin B-12 and their association with vitamin B-12 status markers in healthy older adults in the B-PROOF study

    NARCIS (Netherlands)

    E.M. Brouwer-Brolsma (Elske); R.A.M. Dhonukshe-Rutten (Rosalie); J.P. van Wijngaarden (Janneke); N.L. van der Zwaluw (N.); N. van der Velde (Nathalie); L.C.P.G.M. de Groot (Lisette)

    2015-01-01

    textabstractLow vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations

  3. Passive ranging using a filter-based non-imaging method based on oxygen absorption.

    Science.gov (United States)

    Yu, Hao; Liu, Bingqi; Yan, Zongqun; Zhang, Yu

    2017-10-01

    To solve the problem of poor real-time measurement caused by a hyperspectral imaging system and to simplify the design in passive ranging technology based on oxygen absorption spectrum, a filter-based non-imaging ranging method is proposed. In this method, three bandpass filters are used to obtain the source radiation intensities that are located in the oxygen absorption band near 762 nm and the band's left and right non-absorption shoulders, and a photomultiplier tube is used as the non-imaging sensor of the passive ranging system. Range is estimated by comparing the calculated values of band-average transmission due to oxygen absorption, τ O 2 , against the predicted curve of τ O 2 versus range. The method is tested under short-range conditions. Accuracy of 6.5% is achieved with the designed experimental ranging system at the range of 400 m.

  4. Vitamin B12, folate, and homocysteine in depression: the Rotterdam Study

    NARCIS (Netherlands)

    H.W. Tiemeier (Henning); H.R. van Tuijl (Ruud); J. Meijer (John); A.J. Kiliaan (Amanda); M.M.B. Breteler (Monique); A. Hofman (Albert)

    2002-01-01

    textabstractOBJECTIVE: The associations of vitamin B(12), folate, and homocysteine with depression were examined in a population-based study. METHOD: The authors screened 3,884 elderly people for depressive symptoms. Subjects with positive screening results had psychiatric workups.

  5. Forms and Amounts of Vitamin B12 in Infant Formula: A Pilot Study

    DEFF Research Database (Denmark)

    Greibe, Eva; Nexø, Ebba

    2016-01-01

    12 (cyano-B12). Here we test commercially available infant formulas. METHODS: Eleven commercially available infant formulas were measured for content of B12 and analyzed for the presence of B12-binding proteins and forms of B12 using size exclusion chromatography and HPLC. RESULTS: All infant...... formulas contained B12 by and large in accord with the informations given on the package inserts. None of the formulas contained protein-bound B12, and cyano-B12 accounted for 19-78% of the total amount of B12 present, while hydroxo-B12 constituted more or less the rest. CONCLUSIONS: This pilot study shows...... that infant formula differs from breast milk in providing the infant with free B12, rather than protein-bound B12, and by a relative high content of cyano-B12. The consequence of supplying the infant with synthetic cyano-B12 remains to be elucidated....

  6. Vegetarer har høj risiko for at få B12-vitaminmangel

    DEFF Research Database (Denmark)

    Javid, Parva; Christensen, Erik

    2016-01-01

    Since vegetarians have a lower intake of vitamin B12 (B12) than non-vegetarians, they are at increased risk of developing B12 deficiency. The less animal products the food contains the worse the B12 status. However, even lacto-ovo-vegetarians run the risk of becoming deficient in B12. Vegetarians...... are recommended regularly to take supplements of B12, and they should be informed of the lacking content of B12 of plant products and the hazards of B12 deficiency. Furthermore, vegetarians should routinely be checked for possible B12 deficiency....

  7. The human serum metabolome of vitamin B-12 deficiency and repletion, and associations with neurological function

    Science.gov (United States)

    We characterize the human serum metabolome in sub-clinical vitamin B-12 (B-12) deficiency and repletion. A pre-post treatment study provided one injection of 10 mg B-12 to 27 community-dwelling elderly Chileans with B-12 deficiency evaluated with serum B-12, plasma homocysteine, methylmalonic acid a...

  8. Modeling the reactions catalyzed by coenzyme B12-dependent enzymes.

    Science.gov (United States)

    Sandala, Gregory M; Smith, David M; Radom, Leo

    2010-05-18

    Enzymes accelerate chemical reactions with an exceptional selectivity that makes life itself possible. Understanding the factors responsible for this efficient catalysis is of utmost importance in our quest to harness the tremendous power of enzymes. Computational chemistry has emerged as an important adjunct to experimental chemistry and biochemistry in this regard, because it provides detailed insights into the relationship between structure and function in a systematic and straightforward manner. In this Account, we highlight our recent high-level theoretical investigations toward this end in studying the radical-based reactions catalyzed by enzymes dependent on coenzyme B(12) (or adenosylcobalamin, AdoCbl). In addition to their fundamental position in biology, the AdoCbl-dependent enzymes represent a valuable framework within which to understand Nature's method of efficiently handling high-energy species to execute very specific reactions. The AdoCbl-mediated reactions are characterized by the interchange of a hydrogen atom and a functional group on adjacent carbon atoms. Our calculations are consistent with the conclusion that the main role of AdoCbl is to provide a source of radicals, thus moving the 1,2-rearrangements onto the radical potential energy surface. Our studies also show that the radical rearrangement step is facilitated by partial proton transfer involving the substrate. Specifically, we observe that the energy requirements for radical rearrangement are reduced dramatically with appropriate partial protonation or partial deprotonation or sometimes (synergistically) both. Such interactions are particularly relevant to enzyme catalysis, because it is likely that the local amino acid environment in the active site of an enzyme can function in this capacity through hydrogen bonding. Finally, our calculations indicate that the intervention of a very stable radical along the reaction pathway may inactivate the enzyme, demonstrating that sustained

  9. [Evaluation of the needs and possibilities of increasing the vitamin B12 content in diet].

    Science.gov (United States)

    Sicińska, Ewa; Cholewa, Małgorzata

    2012-01-01

    Vitamin B12 belongs to the biologically active compounds related to cyanocobalamin group. The bioavailability of B12 from different food products varies considerably, for example from the chicken meat it ranges from 61 to 66%, from fish meat is 42%, and from eggs below 9% only. The deficiency of vitamin B12 could easily be overcame by the appropriate diet or food supplements. The aim of this study was to characterize the fortified with vitamin B12 food products available on the market and to assess the possibilities of increasing the intake of this vitamin by including such products into the daily diet. The study was carried out in winter 2011, at eleven Warsaw supermarkets. Information about food products was based on label declarations. There were 220 products fortified with vitamin B12 from various food categories, like breakfast cereals, fruit juice, non-alcoholic beverages, cereals bars, candies, instant cocoa and tea, margarine, as well as soya products. Breakfast cereals (40%) and juice, non-alcoholic beverages (30%) were the largest groups. RESULTS. The highest amount of vitamin B12 was found in some candies (max. 4,5 microg/100 g) and instant tea (max. 3,75 microg/100g). The lowest amount was found in some fruit beverages (min. 0,12 microg/100 g). There is possibility of increasing the vitamin B12 intake by consuming various fortified products: for instance a glass of soya drink (20,8% RDA), a cup of soya pudding (15%), a glass of instant tea (14%), apple juice (12,5%), a cereal bar (10%), a bowl of corn flakes (9,8%) or a slice of bread with margarine (7,5%). The intake of one average portion of chosen food products fortified with vitamin B12 provides about 0,18-0,5 microg (7,5-20,8% Polish RDA for adults). The wide public education is essential for increasing the role of these products in nutrition, it is especially recommendable to vegetarian and elderly people.

  10. The tinker, tailor, soldier in intracellular B12 trafficking.

    Science.gov (United States)

    Banerjee, Ruma; Gherasim, Carmen; Padovani, Dominique

    2009-10-01

    The recognition of eight discrete genetic complementation groups among patients with inherited cobalamin disorders provided early insights into the complexity of a cofactor-processing pathway that supports only two known B(12)-dependent enzymes in mammals. With the identification of all eight genes now completed, biochemical interrogations of their functions have started and are providing novel insights into a trafficking pathway involving porters that tinker with and tailor the active cofactor forms and editors that ensure the fidelity of the cofactor loading process. The principles of sequestration and escorted delivery of a rare and reactive organometallic cofactor that are emerging from studies on B(12) might be of general relevance to other cofactor trafficking pathways.

  11. Vitamin B12 deficiency presenting as acute ataxia.

    Science.gov (United States)

    Crawford, John Ross; Say, Daphne

    2013-03-26

    A previously healthy 7-year-old Caucasian boy was hospitalised for evaluation of acute ataxia and failure to thrive, initially suspicious for an intracranial mass. Weight and body mass index were below the third percentile and he demonstrated loss of joint position and vibratory sense on examination. Laboratory studies revealed megaloblastic anaemia while an initial MRI of the brain showed no evidence of mass lesions or other abnormalities. A dietary history revealed the child subscribed to a restrictive vegan diet with little to no intake of animal products or other fortified foods. The child was diagnosed with presumed vitamin B12 deficiency and was treated with intramuscular B12 injections. Neurological symptoms resolved promptly within several days after starting therapy. This case underlines the importance of assessing nutritional status in the evaluation of neurological dysfunction in the pediatric patient.

  12. [Neurological signs due to isolated vitamin B12 deficiency].

    Science.gov (United States)

    Martinez Estrada, K M; Cadabal Rodriguez, T; Miguens Blanco, I; García Méndez, L

    2013-01-01

    Isolated vitamin B12 deficiency is a common condition in elderly patients but uncommon in patients younger than 30 years, with an average age of onset between 60 and 70 years. This is because the dietary cobalamin, which is normally split by enzymes in meat in the presence of hydrochloric acid and pepsin in the stomach, is not released in the stomachs of elderly patients, usually due to achlorhydria. Although the body may be unable to release cobalamin it does retain the ability to absorb vitamin B12 in its crystalline form, which is present in multivitamin preparations. Other causes are due to drugs that suppress gastric acid production. Neurological signs of vitamin B12 deficiency can occur in patients with a normal haematocrit and red cell indices. They include paresthesia, loss of sensation and strength in the limbs, and ataxia. Reflexes may be slowed down or increased. Romberg and Babinsky signs may be positive, and vibration and position sensitivity often decreases. Behavoural disorders range from irritability and memory loss to severe dementia. The symptoms often do not fully respond to treatment. A case is presented of an isolated vitamin B12 deficiency in 27 year-old female patient who was seen in primary health care. During anamnesis she mentioned low back pain, to which she attributed the loss of strength and tenderness in the right side of the body, as well as the slow and progressive onset of accompanied headache for the previous 4 days. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

  13. White centered retinal hemorrhages in vitamin b(12) deficiency anemia.

    Science.gov (United States)

    Zehetner, Claus; Bechrakis, Nikolaos E

    2011-05-01

    To report a case of severe vitamin B(12) deficiency anemia presenting with white centered retinal hemorrhages. Interventional case report. A 40-year-old man, general practitioner himself, presented with a 1-day history of diminished left visual acuity and a drop-shaped central scotoma. The corrected visual acuities were 20/20, OD and 20/100, OS. Ophthalmic examination revealed bilaterally pale tarsal conjunctiva, discretely icteric bulbar conjunctiva and disseminated white centered intraretinal hemorrhages with foveal involvement. OCT imaging through these lesions revealed a retinal thickening caused by a sub-ILM accumulation of hyperreflective and inhomogeneous deposits within the nerve fiber layer. Immediate laboratory work-up showed severe megaloblastic anemia caused by vitamin B(12) deficiency requiring erythrocyte transfusions. Most reports of white centered retinal hemorrhages have been described in patients with leukemic retinopathy and bacterial endocarditis. It is interesting that this case of vitamin B(12) deficiency anemia retinopathy has a clinically indistinguishable fundus appearance. This is probably due to the common pathology of capillary disruption and subsequent hemostatic fibrin plug formation. In megaloblastic anemia, direct anoxia results in endothelial dysfunction. The loss of impermeability allows extrusion of whole blood and subsequent diffusion from the disrupted site throughout and above the nerve fiber layer. Therefore the biomicroscopic pattern of white centered hemorrhages observed in anemic retinopathy is most likely due to the clot formation as the reparative sequence after capillary rupture.

  14. White Centered Retinal Hemorrhages in Vitamin B12 Deficiency Anemia

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    Claus Zehetner

    2011-05-01

    Full Text Available Background: To report a case of severe vitamin B12 deficiency anemia presenting with white centered retinal hemorrhages. Methods: Interventional case report. Results: A 40-year-old man, general practitioner himself, presented with a 1-day history of diminished left visual acuity and a drop-shaped central scotoma. The corrected visual acuities were 20/20, OD and 20/100, OS. Ophthalmic examination revealed bilaterally pale tarsal conjunctiva, discretely icteric bulbar conjunctiva and disseminated white centered intraretinal hemorrhages with foveal involvement. OCT imaging through these lesions revealed a retinal thickening caused by a sub-ILM accumulation of hyperreflective and inhomogeneous deposits within the nerve fiber layer. Immediate laboratory work-up showed severe megaloblastic anemia caused by vitamin B12 deficiency requiring erythrocyte transfusions. Discussion: Most reports of white centered retinal hemorrhages have been described in patients with leukemic retinopathy and bacterial endocarditis. It is interesting that this case of vitamin B12 deficiency anemia retinopathy has a clinically indistinguishable fundus appearance. This is probably due to the common pathology of capillary disruption and subsequent hemostatic fibrin plug formation. In megaloblastic anemia, direct anoxia results in endothelial dysfunction. The loss of impermeability allows extrusion of whole blood and subsequent diffusion from the disrupted site throughout and above the nerve fiber layer. Therefore the biomicroscopic pattern of white centered hemorrhages observed in anemic retinopathy is most likely due to the clot formation as the reparative sequence after capillary rupture.

  15. Vitamin B-12 Concentrations in Breast Milk Are Low and Are Not Associated with Reported Household Hunger, Recent Animal-Source Food, or Vitamin B-12 Intake in Women in Rural Kenya.

    Science.gov (United States)

    Williams, Anne M; Chantry, Caroline J; Young, Sera L; Achando, Beryl S; Allen, Lindsay H; Arnold, Benjamin F; Colford, John M; Dentz, Holly N; Hampel, Daniela; Kiprotich, Marion C; Lin, Audrie; Null, Clair A; Nyambane, Geoffrey M; Shahab-Ferdows, Setti; Stewart, Christine P

    2016-05-01

    Breast milk vitamin B-12 concentration may be inadequate in regions in which animal-source food consumption is low or infrequent. Vitamin B-12 deficiency causes megaloblastic anemia and impairs growth and development in children. We measured vitamin B-12 in breast milk and examined its associations with household hunger, recent animal-source food consumption, and vitamin B-12 intake. In a cross-sectional substudy nested within a cluster-randomized trial assessing water, sanitation, hygiene, and nutrition interventions in Kenya, we sampled 286 women 1-6 mo postpartum. Mothers hand-expressed breast milk 1 min into a feeding after 90 min observed nonbreastfeeding. The Household Hunger Scale was used to measure hunger, food intake in the previous week was measured with the use of a food-frequency questionnaire (FFQ), and vitamin B-12 intake was estimated by using 24-h dietary recall. An animal-source food score was based on 10 items from the FFQ (range: 0-70). Breast milk vitamin B-12 concentration was measured with the use of a solid-phase competitive chemiluminescent enzyme immunoassay and was modeled with linear regression. Generalized estimating equations were used to account for correlated observations at the cluster level. Median (IQR) vitamin B-12 intake was 1.5 μg/d (0.3, 9.7 μg/d), and 60% of women consumed hunger prevalence was 27%; the animal-source food score ranged from 0 to 30 item-d/wk. Hunger and recent animal-source food and vitamin B-12 intake were not associated with breast milk vitamin B-12 concentrations. Maternal age was negatively associated with breast milk vitamin B-12 concentrations. Most lactating Kenyan women consumed less than the estimated average requirement of vitamin B-12 and had low breast milk vitamin B-12 concentrations. We recommend interventions that improve vitamin B-12 intake in lactating Kenyan women to foster maternal health and child development. The main trial was registered at clinicaltrials.gov as NCT01704105. © 2016

  16. SELF-ABSORPTION CORRECTIONS BASED ON MONTE CARLO SIMULATIONS

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    Kamila Johnová

    2016-12-01

    Full Text Available The main aim of this article is to demonstrate how Monte Carlo simulations are implemented in our gamma spectrometry laboratory at the Department of Dosimetry and Application of Ionizing Radiation in order to calculate the self-absorption within the samples. A model of real HPGe detector created for MCNP simulations is presented in this paper. All of the possible parameters, which may influence the self-absorption, are at first discussed theoretically and lately described using the calculated results.

  17. Vitamin B12 supplementation and cognitive scores in geriatric patients with Mild Cognitive Impairment

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    Komal Chauhan

    2016-09-01

    Full Text Available Background: The Neurodegenerative diseases are increasingly affecting the elderly with a severe impact on their brain health. There is a wide gap in supplementation based studies for increasing the cognition levels of the geriatric population, especially in developing countries like India which are at extreme risk of developing neurological disorders. And recently Vitamin B12 has drawn considerable attention due to its ability to improve the cognitive status. Current literature has linked the possibility of alleviating neurological disorders in the elderly with effective vitamin B12 management. Abundant animal and human models have proved that supplementation of vitamin B12 is beneficial for the restoration of cognitive functions. Objective: To supplement vitamin B12 deficient mild cognitively impaired geriatric patients with injectable doses of vitamin B12 followed by impact evaluation. Methods: Screening of the mild cognitively impaired patients was carried out using the Mini- Mental State Examination and Yamaguchi Fox Pigeon Imitation test. Baseline information was elicited from the patients residing in urban Vadodara (a district in the state of Gujarat, India. This included socio-demographic, medical and drug history, anthropometric and physical activity pattern, in addition to biochemical parameters comprising of serum vitamin B12 and glycated haemoglobin profile. A sub-sample of 60 patients with mild cognitive impairment (MCI demonstrating severe vitamin B12 deficiency were conveniently enrolled for injectable doses of Vitamin B 12 in the dosage of 1,000 µg every day for one week, followed by 1,000 µg every week for 4 weeks & finishing with 1,000 µg for the remaining 4 months. An intervention six- month after the experiment with all the parameters were elicited. Results: Vitamin B12 supplementation resulted in a significant (p<0.001 improvement in the MMSE scores of the patients with a rise of 9.63% in the total patients. Gender

  18. Low-temperature heat capacity and thermodynamic functions of vitamin B12

    International Nuclear Information System (INIS)

    Knyazev, A.V.; Smirnova, N.N.; Plesovskikh, A.S.; Shushunov, A.N.; Knyazeva, S.S.

    2014-01-01

    Graphical abstract: - Highlights: • Temperature dependence of heat capacity of vitamin B 12 has been measured by precision adiabatic vacuum calorimetry. • The thermodynamic functions of the vitamin B 12 have been determined for the range from T → 0 to 343 K. • The character of heterodynamics of structure was detected. • The thermal stability of cyanocobalamin was studied by differential scanning calorimetry. - Abstract: In the present work temperature dependence of heat capacity of vitamin B 12 (cyanocobalamin) has been measured for the first time in the range from 6 to 343 K by precision adiabatic vacuum calorimetry. Based on the experimental data, the thermodynamic functions of the vitamin B 12 , namely, the heat capacity, enthalpy H°(T) − H°(0), entropy S°(T) − S°(0) and Gibbs function G°(T) − H°(0) have been determined for the range from T → 0 to 343 K. The value of the fractal dimension D in the function of multifractal generalization of Debye's theory of the heat capacity of solids was estimated and the character of heterodynamics of structure was detected. The thermal stability of cyanocobalamin was also studied by differential scanning calorimetry

  19. Dietary Sources of Vitamin B-12 and Their Association with Vitamin B-12 Status Markers in Healthy Older Adults in the B-PROOF Study

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    Elske M. Brouwer-Brolsma

    2015-09-01

    Full Text Available Low vitamin B-12 concentrations are frequently observed among older adults. Malabsorption is hypothesized to be an important cause of vitamin B-12 inadequacy, but serum vitamin B-12 may also be differently affected by vitamin B-12 intake depending on food source. We examined associations between dietary sources of vitamin B-12 (meat, fish and shellfish, eggs, dairy and serum vitamin B-12, using cross-sectional data of 600 Dutch community-dwelling adults (≥65 years. Dietary intake was assessed with a validated food frequency questionnaire. Vitamin B-12 concentrations were measured in serum. Associations were studied over tertiles of vitamin B-12 intake using P for trend, by calculating prevalence ratios (PRs, and splines. Whereas men had significantly higher vitamin B-12 intakes than women (median (25th–75th percentile: 4.18 (3.29–5.38 versus 3.47 (2.64–4.40 μg/day, serum vitamin B-12 did not differ between the two sexes (mean ± standard deviation (SD: 275 ± 104 pmol/L versus 290 ± 113 pmol/L. Higher intakes of dairy, meat, and fish and shellfish were significantly associated with higher serum vitamin B-12 concentrations, where meat and dairy—predominantly milk were the most potent sources. Egg intake did not significantly contribute to higher serum vitamin B-12 concentrations. Thus, dairy and meat were the most important contributors to serum vitamin B-12, followed by fish and shellfish.

  20. Investigation for preparation and production of radio-kit Vitamin B12 with med-grade (part 1)

    International Nuclear Information System (INIS)

    Ghafourian, H.; Mazaheri Tehrani, M.; Ezadyar, A.; Shams Rafiee, M.; Nazari, A.

    2005-01-01

    Labelled vitamins B 12 with 58 Co is one of the important ingredients of the diagnostic Kits for diagnosis of patients affected by anemia. The insufficient absorption of vitamin B 12 is one of the causes of anemia in humans and one of the accurate methods for measurement of the absorbed vitamin B 12 is application of labelled vitamin B 12 with the cobalt-58 radioisotope.The isolation and purifications of the labelled vitamin B 12 from fermentation medium of streptomyces olivaceus is an essential process for kit preparation. The first experiment in this research was isolation and purification of B 12 using different resins with the solution of cyanocobalamin containing cobalt-59, produced by this bacterium. After investigation and pre-feasibility experiments two non-polar resins XAD-4 and XAD-7 were selected. The results that obtained from different experiments on XAD-4 and XAD-7 showed that XAD-4 is much better than the latter one due to immobilization of cobalamin. The isolation of vitamin B1 2 on XAD-4 column was achieved by different solvents such as methanol, ethanol and isopropanol in different concentration ratios. The results of Thin Layer Chromatography showed that the best eluant solutions for desorbtion of cobalamin from XAD-4 column are solvents such as methanol,ethanol and isopropanol with the maximum concentration of vitamin B 12 in the concentration ranges of 25 up to 50 per-cent, 30 up to 40 per-cent and 10 per-cent, respectively. Cobalamin was collected in aceton and crystallized in low temperature

  1. Recreational Nitrous Oxide Abuse-Induced Vitamin B12 Deficiency in a Patient Presenting with Hyperpigmentation of the Skin

    Directory of Open Access Journals (Sweden)

    Tsung-Ta Chiang

    2013-06-01

    Full Text Available Vitamin B12 deficiency causes skin hyperpigmentation, subacute combined degeneration of the spinal cord, and megaloblastic anemia. Although vitamin B12 deficiency rarely occurs in well-nourished, healthy, young people, nitrous oxide (N2O intoxication is an important cause of vitamin B12 deficiency in this cohort. N2O, a colorless gas used as an anesthetic since the late 19th century because of its euphoric and analgesic qualities, is now used as a recreational drug and is available via the Internet and at clubs. Here, we describe the case of a 29-year-old woman presenting with skin hyperpigmentation as her only initial symptom after N2O abuse for approximately 2 years. N2O intoxication-induced vitamin B12 deficiency was diagnosed based on the skin pigmentation that had manifested over the dorsa of her fingers, toes, and trunk, coupled with myeloneuropathy of the posterior and lateral columns, a low serum vitamin B12 level, an elevated serum homocysteine level, and the N2O exposure revealed while establishing the patient's history. Symptoms improved significantly with vitamin B12 treatment. We recommend that dermatologists consider N2O intoxication-induced vitamin B12 deficiency as a potential cause of skin hyperpigmentation and myeloneuropathy of the posterior and lateral columns in young, otherwise healthy patients. Failure to recognize this presentation may result in inappropriate treatment, thus affecting patients' clinical outcomes.

  2. Vitamin B12 deficiency - a major cause of megaloblastic anaemia in patients attending a tertiary care hospital

    International Nuclear Information System (INIS)

    Iqbal, S.P.; Kakepoto, G.N.; Iqbal, S.P.

    2009-01-01

    Folate and vitamin B12 deficiencies have been known to cause megaloblastic anaemia. Since the deficiencies of these two vitamins are very common in Pakistani population, it would be imperative to investigate their role in causing megaloblastic anaemia. The objective of this study was to find out the contribution of folate and vitamin B12 deficiencies in causing megaloblastic anaemia in our patient population. Methods: In this retrospective cohort study, clinical records of 220 patients (101 females and 119 males with an age range of 1 - 80 years) who presented themselves with macrocytic anaemia at the Aga Khan University Hospital were collected. Data pertaining to complete blood count and serum levels of folate and vitamin B12 were analysed. Results: The mean haemoglobin (Hb) level was 6.8 +- 0.2 gm/dl. Sixty-nine percent of the patients had severe anaemia (Hb<8 gm/dl). Mean +- SEM values of haemoglobin, serum folate and serum B12 were not significantly different between males and females (Hb 6.4 +- 0.3 gm/dl vs 6.3 +- 0.3 gm/dl; folate 6.9 +- 0.8 mu g/ml vs 7.8 +- 1 mu g/ml; B12 259 +- 65 mu g/ml vs 225 +- 45 mu g/ml, respectively). Linear regression analysis showed that serum folate was inversely related with the mean corpuscular volume (MCV, p=0.04). Spearman's correlation analysis indicated an inverse mild association between MCV and serum folate (correlation coefficient= -0.18). Folate deficiency was 43.4%, while vitamin B12 deficiency was 78.5% in these patients. Seventy-one percent of folate-deficient patients had vitamin B12 deficiency as well, while 26.1% of patients with B12 deficiency had a co-occurrence of folate deficiency. Conclusion: Vitamin B12 deficiency appears to be the major factor leading to megaloblastic anaemia in our study population. Inadequate dietary intake, over-cooking of our food and poor absorption might be contributing to high prevalence of vitamin B12 deficiency in this population. (author)

  3. [Stability of folic acid and vitamin B12 in TPN].

    Science.gov (United States)

    Almodóvar, M J; Hernández Jaras, M V; León-Sanz, M; Ortuño, B; Estenoz, J; Negro Vega, E; Marfagón, N; Herreros de Tejada, A

    1991-01-01

    The stability of folic acid (FA) in mixtures of Total Parenteral Nutrition has been and is a controversial subject, with discussion concerning the influence of factors such as temperature, light and storage time. As regards the stability of the vitamin B12, there are few studies in scientific literature. For all those reasons, we consider it necessary to make a proper study to evaluate the influence of different factors in the stability of both vitamins. The study was made on 3 liter TPN bags of the EVA type, the composition of which was as follows: AA (85g), glucosa (225g), fat (50g), Na (86mEq), K (60 mEq), Ca (15 mEq), Cl (90 mEq), P (17 mmol) acetate (149 mEq) and 10 ml of MVI-12 which contain 400 micrograms of PA and 5 micrograms of Vitamin B 12. Consideration was also given to the stability of these two vitamins in the same diet, to which were added 10 ml of a commercial preparation of oligo-elements. Six TPN bags were prepared (without oligo-elements); two of them were kept in a fridge and protected from the light, two were kept at room temperature and protected from the light and the other two at room temperature without protection from the light. Samples were taken from all the bags immediately after their preparation and after 24, 48, 72 and 96 hours. The same process was carried with other TPN bags which did contain oligo-elements. The method for determining FA and Vitamin B12 was by radioassay.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Preparation and Characterization of Cyanocobalamin (Vit B12 Microemulsion Properties and Structure for Topical and Transdermal Application

    Directory of Open Access Journals (Sweden)

    Anayatollah Salimi

    2013-07-01

    This study showed that both microemulsions provided good solubility of Vit B12 with a wide range of internal structure. Low water solubilization capacity is a common property of microemulsions that can affect drug release and permeability through the skin. Based on Vit B12 properties, specially, intermediate oil and water solubility, better drug partitioning into the skin may be obtained by traditional formulations with wide range of structure and high amount of free and bounded water.

  5. Vitamin B-12 supplementation during pregnancy and early lactation increases maternal, breast milk, and infant measures of vitamin B-12 status.

    Science.gov (United States)

    Duggan, Christopher; Srinivasan, Krishnamachari; Thomas, Tinku; Samuel, Tinu; Rajendran, Ramya; Muthayya, Sumithra; Finkelstein, Julia L; Lukose, Ammu; Fawzi, Wafaie; Allen, Lindsay H; Bosch, Ronald J; Kurpad, Anura V

    2014-05-01

    Pregnant women in resource-poor areas are at risk of multiple micronutrient deficiencies, and indicators of low vitamin B-12 status have been associated with adverse pregnancy outcomes, including anemia, low birth weight, and intrauterine growth retardation. To evaluate whether daily oral vitamin B-12 supplementation during pregnancy increases maternal and infant measures of vitamin B-12 status, we performed a randomized, placebo-controlled clinical trial. Pregnant women vitamin B-12 (50 μg) or placebo through 6 wk postpartum. All women were administered iron and folic acid supplements throughout pregnancy. One hundred eighty-three women were randomly assigned to receive vitamin B-12 and 183 to receive placebo. Compared with placebo recipients, vitamin B-12-supplemented women had significantly higher plasma vitamin B-12 concentrations at both the second (median vitamin B-12 concentration: 216 vs. 111 pmol/L, P vitamin B-12 concentration was 136 pmol/L in vitamin B-12-supplemented women vs. 87 pmol/L in the placebo group (P vitamin B-12-supplemented women, the incidence of delivering an infant with intrauterine growth retardation was 33 of 131 (25%) vs. 43 of 125 (34%) in those administered placebo (P = 0.11). In a subset of infants tested at 6 wk of age, median plasma vitamin B-12 concentration was 199 pmol/L in those born to supplemented women vs. 139 pmol/L in the placebo group (P = 0.01). Infant plasma methylmalonic acid and homocysteine concentrations were significantly lower in the vitamin B-12 group as well. Oral supplementation of urban Indian women with vitamin B-12 throughout pregnancy and early lactation significantly increases vitamin B-12 status of mothers and infants. It is important to determine whether there are correlations between these findings and neurologic and metabolic functions. This trial was registered at clinicaltrials.gov as NCT00641862.

  6. Direct Rehydrogenation of LiBH4 from H-Deficient Li2B12H12−x

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    Yigang Yan

    2018-03-01

    Full Text Available Li2B12H12 is commonly considered as a boron sink hindering the reversible hydrogen sorption of LiBH4. Recently, in the dehydrogenation process of LiBH4 an amorphous H-deficient Li2B12H12−x phase was observed. In the present study, we investigate the rehydrogenation properties of Li2B12H12−x to form LiBH4. With addition of nanostructured cobalt boride in a 1:1 mass ratio, the rehydrogenation properties of Li2B12H12−x are improved, where LiBH4 forms under milder conditions (e.g., 400 °C, 100 bar H2 with a yield of 68%. The active catalytic species in the reversible sorption reaction is suggested to be nonmetallic CoxB (x = 1 based on 11B MAS NMR experiments and its role has been discussed.

  7. Severe but Not Moderate Vitamin B12 Deficiency Impairs Lipid Profile, Induces Adiposity, and Leads to Adverse Gestational Outcome in Female C57BL/6 Mice.

    Science.gov (United States)

    Ghosh, Shampa; Sinha, Jitendra Kumar; Putcha, Uday Kumar; Raghunath, Manchala

    2016-01-01

    Vitamin B12 deficiency is widely prevalent in women of childbearing age, especially in developing countries. In the present study, through dietary restriction, we have established mouse models of severe and moderate vitamin B12 deficiencies to elucidate the impact on body composition, biochemical parameters, and reproductive performance. Female weanling C57BL/6 mice were fed for 4 weeks: (a) control AIN-76A diet, (b) vitamin B12-restricted AIN-76A diet with pectin as dietary fiber (severe deficiency group, as pectin inhibits vitamin B12 absorption), or (c) vitamin B12-restricted AIN-76A diet with cellulose as dietary fiber (moderate deficiency group as cellulose does not interfere with vitamin B12 absorption). After confirming deficiency, the mice were mated with male colony mice and maintained on their respective diets throughout pregnancy, lactation, and thereafter till 12 weeks. Severe vitamin B12 deficiency increased body fat% significantly, induced adiposity and altered lipid profile. Pregnant dams of both the deficient groups developed anemia. Severe vitamin B12 deficiency decreased the percentage of conception and litter size, pups were small-for-gestational-age and had significantly lower body weight at birth as well as weaning. Most of the offspring born to severely deficient dams died within 24 h of birth. Stress markers and adipocytokines were elevated in severe deficiency with concomitant decrease in antioxidant defense. The results show that severe but not moderate vitamin B12 restriction had profound impact on the physiology of C57BL/6 mice. Oxidative and corticosteroid stress, inflammation and poor antioxidant defense seem to be the probable underlying mechanisms mediating the deleterious effects.

  8. Severe but not moderate vitamin B12 deficiency impairs lipid profile, induces adiposity and leads to adverse gestational outcome in female C57BL/6 mice

    Directory of Open Access Journals (Sweden)

    Shampa eGhosh

    2016-01-01

    Full Text Available Vitamin B12 deficiency is widely prevalent in women of childbearing age especially in developing countries. In the present study, through dietary restriction, we have established mouse models of severe and moderate vitamin B12 deficiencies to elucidate the impact on body composition, biochemical parameters and reproductive performance. Female weanling C57BL/6 mice were fed for four weeks, (a control AIN-76A diet, (b vitamin B12 restricted AIN-76A diet with pectin as dietary fiber (severe deficiency group, as pectin inhibits vitamin B12 absorption or (c vitamin B12 restricted AIN-76A diet with cellulose as dietary fiber (moderate deficiency group as cellulose does not interfere with vitamin B12 absorption. After confirming deficiency, the mice were mated with male colony mice and maintained on their respective diets throughout pregnancy, lactation and thereafter till 12 weeks. Severe vitamin B12 deficiency increased body fat % significantly, induced adiposity and altered lipid profile. Pregnant dams of both the deficient groups developed anemia. Severe vitamin B12 deficiency decreased the percentage of conception and litter size, pups were small-for-gestational-age and had significantly lower body weight at birth as well as weaning. Most of the offspring born to severely deficient dams died within 24 hours of birth. Stress markers and adipocytokines were elevated in severe deficiency with concomitant decrease in antioxidant defense. The results show that severe but not moderate vitamin B12 restriction had profound impact on the physiology of C57BL/6 mice. Oxidative and corticosteroid stress, inflammation and poor antioxidant defense seem to be the probable underlying mechanisms mediating the deleterious effects.

  9. Wideband absorption in one dimensional photonic crystal with graphene-based hyperbolic metamaterials

    Science.gov (United States)

    Kang, Yongqiang; Liu, Hongmei

    2018-02-01

    A broadband absorber which was proposed by one dimensional photonic crystal (1DPC) containing graphene-based hyperbolic metamaterials (GHMM) is theoretically investigated. For TM mode, it was demonstrated to absorb roughly 90% of all available electromagnetic waves at a 14 THz absorption bandwidth at normal incidence. The absorption bandwidth was affected by Fermi energy and thickness of dielectric layer. When the incident angle was increased, the absorption value decreased, and the absorption band had a gradual blue shift. These findings have potential applications for designing broadband optoelectronic devices at mid-infrared and THz frequency range.

  10. Rapidly reconfigurable slow-light system based on off-resonant Raman absorption

    International Nuclear Information System (INIS)

    Vudyasetu, Praveen K.; Howell, John C.; Camacho, Ryan M.

    2010-01-01

    We present a slow-light system based on dual Raman absorption resonances in warm rubidium vapor. Each Raman absorption resonance is produced by a control beam in an off-resonant Λ system. This system combines all optical control of the Raman absorption and the low-dispersion broadening properties of the double Lorentzian absorption slow light. The bandwidth, group delay, and central frequency of the slow-light system can all be tuned dynamically by changing the properties of the control beam. We demonstrate multiple pulse delays with low distortion and show that such a system has fast switching dynamics and thus fast reconfiguration rates.

  11. Improvement of intestinal absorption of forsythoside A in weeping forsythia extract by various absorption enhancers based on tight junctions.

    Science.gov (United States)

    Zhou, Wei; Qin, Kun Ming; Shan, Jin Jun; Ju, Wen Zheng; Liu, Shi Jia; Cai, Bao Chang; Di, Liu Qing

    2012-12-15

    Forsythoside A (FTA), one of the main active ingredients in weeping forsythia extract, possesses strong antibacterial, antioxidant and antiviral effects, and its content was about 8% of totally, higher largely than that of other ingredients, but the absolute bioavailability orally was approximately 0.5%, which is significant low influencing clinical efficacies of its oral preparations. In the present study, in vitro Caco-2 cell, in situ single-pass intestinal perfusion and in vivo pharmacokinetics study were performed to investigate the effects of absorption enhancers based on tight junctions: sodium caprate and water-soluble chitosan on the intestinal absorption of FTA, and the eventual mucosal epithelial damage resulted from absorption enhancers was evaluated by MTT test, measurement of total amount of protein and the activity of LDH and morphology observation, respectively. The pharmacological effects such as antioxidant activity improvement by absorption enhancers were verified by PC12 cell damage inhibition rate after H₂O₂ insults. The observations from in vitro Caco-2 cell showed that the absorption of FTA in weeping forsythia extract could be improved by absorption enhancers. Meanwhile, the absorption enhancing effect of water-soluble chitosan may be almost saturable up to 0.0032% (w/v), and sodium caprate at concentrations up to 0.64 mg/ml was safe for the Caco-2 cells, but water-soluble chitosan at different concentrations was all safe for these cells. The observations from single-pass intestinal perfusion in situ model showed that duodenum, jejunum, ileum and colon showed significantly concentration-dependent increase in P(eff)-value, and that P(eff)-value in the ileum and colon groups, where sodium caprate was added, was higher than that of duodenum and jejunum groups, but P(eff)-value in the jejunum group was higher than that of duodenum, ileum and colon groups where water-soluble chitosan was added. Intestinal mucosal toxicity studies showed no

  12. Diffusion of Vitamin B12 Across a Mesoporous Metal Organic Framework

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    Veronica Valencia

    2013-01-01

    Full Text Available We measure the rate of uptake and the rate of release of a Vitamin B12 solution (dissolved in water at 2 different temperatures (room temperature and 37°C by the mesoporous metal organic framework TbMOF-100 at 1-hour intervals using a spectrophotometer. Using the Beer-Lambert law, we calculate the concentration of the stock solution based on the absorbance values obtained with the spectrophotometer. These values allow for the quantification of the initial rate of uptake and the rate of uptake at a random incubation time of the Vitamin B12 by the TbMOF-100. We also calculate the value of the coefficient of diffusion for this 2-phase system using Fick’s laws of diffusion.

  13. Tunable THz perfect absorber with two absorption peaks based on graphene microribbons

    DEFF Research Database (Denmark)

    Gu, Mingyue; Xiao, Binggang; Xiao, Sanshui

    2018-01-01

    Perfect absorption is characterised by the complete suppression of incident and reflected electromagnetic wave, and complete dissipation of the incident energy. A tunable perfect terahertz (THz) absorber with two absorption peaks based on graphene is presented. The proposed structure consists of ...

  14. Tissue distribution of oral vitamin B12 is influenced by B12 status and B12 form: an experimental study in rats

    DEFF Research Database (Denmark)

    Kornerup, Linda Skibsted; Fedosov, Sergey; Juul, Christian Bredgaard

    2017-01-01

     k in/k out) in all organs except for the kidney, where the ratio decreased considerably. Twenty-four-hour accumulation of labelled Cbl showed that HOCbl > CNCbl (liver) and CNCbl > HOCbl (brain, muscle and plasma). CONCLUSIONS......PURPOSE: Hydroxocobalamin (HOCbl) is the dominating Cbl form in food, whereas cyanocobalamin (CNCbl) is common in vitamin pills and oral supplements. This study compares single-dose absorption and distribution of oral HO[57Co]Cbl and CN[57Co]Cbl in Cbl-deficient and normal rats. METHODS: Male......, heart, spleen, intestines, skeletal muscle, 24-h urine and faeces were collected, and the content of [57Co]Cbl was measured. Endogenous Cbl in tissues and plasma was analysed by routine methods. RESULTS: Mean endogenous plasma-Cbl was sevenfold lower in deficient vs. normal rats (190 vs. 1330 pmol/L, p...

  15. Effects of Chemical and Physical Enhancement Techniques on Transdermal Delivery of Cyanocobalamin (Vitamin B12 In Vitro

    Directory of Open Access Journals (Sweden)

    Ajay K. Banga

    2011-08-01

    Full Text Available Vitamin B12 deficiency, which may result in anemia and nerve damage if left untreated, is currently treated by administration of cyanocobalamin via oral or intramuscular routes. However, these routes are associated with absorption and compliance issues which have prompted us to investigate skin as an alternative site of administration. Delivery through skin, however, is restricted to small and moderately lipophilic molecules due to the outermost barrier, the stratum corneum (SC. In this study, we have investigated the effect of different enhancement techniques, chemical enhancers (ethanol, oleic acid, propylene glycol, iontophoresis (anodal iontophoresis and microneedles (soluble maltose microneedles, which may overcome this barrier and improve cyanocobalamin delivery. Studies with different chemical enhancer formulations indicated that ethanol and oleic acid decreased the lag time while propylene glycol based formulations increased the lag time. The formulation with ethanol (50%, oleic acid (10% and propylene glycol (40% showed the maximum improvement in delivery. Iontophoresis and microneedle treatments resulted in enhanced permeation levels compared to passive controls. These enhancement approaches can be explored further to develop alternative treatment regimens.

  16. Vitamin B12 transport from food to the body's cells--a sophisticated, multistep pathway

    DEFF Research Database (Denmark)

    Nielsen, Marianne J; Rasmussen, Mie R; Andersen, Christian B F

    2012-01-01

    Vitamin B(12) (B(12); also known as cobalamin) is a cofactor in many metabolic processes; deficiency of this vitamin is associated with megaloblastic anaemia and various neurological disorders. In contrast to many prokaryotes, humans and other mammals are unable to synthesize B(12). Instead...... in the transport pathway are also known culprits of functional B(12) deficiency. Biochemical and genetic approaches have identified novel proteins in the B(12) transport pathway--now known to involve more than 15 gene products--delineating a coherent pathway for B(12) trafficking from food to the body's cells...

  17. Simultaneous radioassay of serum vitamin B12 and folic acid

    International Nuclear Information System (INIS)

    Gutcho, S.; Mansbach, L.

    1977-01-01

    The radioassays of vitamin B 12 and folic acid can be carried out in a single tube to give the simultaneous assay of both vitamins in 100 μl of serum. Release of bound vitamins from their endogenous binders and the destruction of these binders are effected by a heating step at pH 9.3. The subsequent binding reactions with hog intrinsic factor and milk binder protein proceed advantageously and simultaneously in the same tube at pH 9.3. A single set of dual reagents replaces two sets of reagents that would normally be used for separate radioassays. Complete separation of bound radioactivities, [ 57 Co] cyanocobalamin and 125 I-labeled folate derivative, is obtained in a dual-channel gamma counter with no requirement for any correction for spill-over of counting data. Analytical results are comparable to those found for previously developed individual radioassays. The simultaneous assay has decreased technical time of analysis for these interrelated vitamins by about 50%

  18. Multivitamin Use and Serum Vitamin B12 Concentrations in Older-Adult Metformin Users in REGARDS, 2003-2007.

    Science.gov (United States)

    Kancherla, Vijaya; Garn, Joshua V; Zakai, Neil A; Williamson, Rebecca S; Cashion, Winn T; Odewole, Oluwaseun; Judd, Suzanne E; Oakley, Godfrey P

    2016-01-01

    Metformin, an insulin-sensitizing drug, is a first line treatment for type 2 diabetes. Long-term use of metformin has been associated with subsequent reductions in vitamin B12 concentrations. The objective of our study was to determine whether metformin use is associated with lower serum vitamin B12 concentrations in older adults, and whether concurrent use of multivitamins modifies this association. We examined 2,510 participants aged 50 years and over, participating in the national population-based Reasons for Geographic And Racial Differences in Stroke (REGARDS) Study. Multivariable linear and logistic regression models were used to assess associations between multivitamin use and serum vitamin B12 concentrations. We estimated adjusted odds ratios (aOR)s and confidence intervals (CI)s. Results were stratified by three metformin/diabetes sub-groups: 1) participants with diabetes who were metformin users; 2) participants with diabetes who were not metformin users; and 3) participants without diabetes. We found that diabetic metformin users had significantly lower geometric mean serum B12 concentrations (409 pmol/L) than the group with diabetes not taking metformin (485 pmol/L; PL; P = 0.02). The geometric mean serum B12 concentrations were greater for multivitamin users (509 pmol/L) compared to those who did not use multivitamins (376 pmol/L; pvitamin B12 concentrations that were 50% (or 161 pmol/L) higher, compared to those not using multivitamins. Among metformin users, multivitamin use was associated with lower prevalence of combined low and borderline vitamin B12 concentrations (aOR = 0.14; 95% CI = 0.04, 0.54) compared to those not using multivitamins. In conclusion, metformin use was associated with lower geometric mean serum vitamin B12 concentrations among diabetic older adults compared to their counterparts. Concurrent multivitamin use may potentially protect against low or borderline vitamin B12 concentrations in long-term metformin users. Additional

  19. Spectroscopic investigations of the B12-binding subunit of glutamate mutase: refined solution structure of the complex with the B12-nucleotide, dynamics and binding studies with two corrinoid cofactors

    International Nuclear Information System (INIS)

    Eichmueller, C.

    2002-06-01

    Glutamate mutase is an enzyme isolated from Clostridium tetanomorphum and Clostridium cochlearum. It catalyses the reversible rearrangement of (2S)-glutamate to (2S,3S)-3-methylaspartate. Coenzyme B12 is required as cofactor for an active enzyme, as the first step of the catalytic cycle is the homolytic cleavage of the cobalt-carbon bond. The rearrangement itself follows a radical mechanism. The holoenzyme is an alpha2beta2 heterotetramer containing two identical catalytic and two B12 binding domains, as well as two coenzyme B12 molecules. The smaller B12 binding domain from Clostridium tetanomorphum, MutS, is known to bind coenzyme B12 in its unusual 'base-off' form. A conserved histidine residue coordinates to the cobalt atom instead of the normally coordinated dimethlybenzimidole in free coenzyme B12. In the present work a refined solution structure of the B12 binding subunit from Clostridium tetanomorphum (MutS) in complex with the detached nucleotide loop of coenzyme B12 has been determined using nuclear magnetic resonance. The found topology is almost identical to the crystal structure of glutamate mutase from C.cochlearum [Reitzer et al., 1999], in contrast to the solution structures obtained for apo-MutS [Hoffmann et al., 2001; Tollinger et al., 1998] and apo-GlmS [Hoffmann et al., 1999]. In these two structures a helix at one side of the B12 nucleotide loop binding pocket is mostly unstructured and shows motions on a microsecond to millisecond timescale. The previously found stabilization of this helix upon B12-nucleotide binding [Tollinger et al., 2001] was confirmed using 13C and 15N labeled MutS. Some differences are found in the structure of the binding pocket and the bound nucleotide loop compared to the crystal structure. This indicates that additional conformational changes occur upon binding of the corrin ring of coenzyme B12. NMR-relaxation measurements performed on apo-MutS showed interesting slow molecular motions not only in the mainly

  20. Homocysteine, vitamin B12 and folate levels in premature coronary artery disease

    Directory of Open Access Journals (Sweden)

    Fallah Nader

    2006-09-01

    Full Text Available Abstract Background Hyperhomocysteinemia is known as an independent risk factor of atherosclerosis, but the probable role of hyperhomocysteinemia in premature Coronary Artery Disease (CAD is not well studied. The aim of this study was to assess the role of hyperhomocysteinemia, folate and Vitamin B12 deficiency in the development of premature CAD. Methods We performed an analytical case-control study on 294 individuals under 45 years (225 males and 69 females who were admitted for selective coronary angiography to two centers in Tehran. Results After considering the exclusion criteria, a total number of 225 individuals were enrolled of which 43.1% had CAD. The mean age of participants was 39.9 +/- 4.3 years (40.1 +/- 4.2 years in males and 39.4 +/- 4.8 years in females. Compared to the control group, the level of homocysteine measured in the plasma of the male participants was significantly high (14.9 +/- 1.2 versus 20.3 +/- 1.9 micromol/lit, P = 0.01. However there was no significant difference in homocysteine level of females with and without CAD (11.8 +/- 1.3 versus 11.5 ± 1.1 micromol/lit, P = 0.87. Mean plasma level of folic acid and vitamin B12 in the study group were 6.3 +/- 0.2 and 282.5 +/- 9.1 respectively. Based on these findings, 10.7% of the study group had folate deficiency while 26.6% had Vitamin B12 deficiency. Logistic regression analysis for evaluating independent CAD risk factors showed hyperhomocysteinemia as an independent risk factor for premature CAD in males (OR = 2.54 0.95% CI 1.23 to 5.22, P = 0.01. Study for the underlying causes of hyperhomocysteinemia showed that male gender and Vitamin B12 deficiency had significant influence on incidence of hyperhomocysteinemia. Conclusion We may conclude that hyperhomocysteinemia is an independent risk factor for CAD in young patients (bellow 45 years old – especially in men -and vitamin B12 deficiency is a preventable cause of hyperhomocysteinemia.

  1. Vitamin B12 deficiency presenting as an acute confusional state: a ...

    African Journals Online (AJOL)

    EB

    2013-09-03

    Sep 3, 2013 ... occurred following parenteral vitamin B12 replacement therapy. Conclusion: This case report highlights one of the neuro-psychiatric presentations of vitamin B12 deficiency .... and Occupational Health Abstract No:.

  2. Evaluation of serum Vitamin B12 level and related nutritional status ...

    African Journals Online (AJOL)

    2016-03-29

    Mar 29, 2016 ... This study was aimed to investigate the association between serum. Vitamin B12 ... Consumption of certain types of food contributes to increase vitB12 level. Key words: ... nutritional status among apparently healthy obese.

  3. vitamin b12 levels in patients with type 2 diabetes mellitus

    African Journals Online (AJOL)

    is involved in DNA synthesis, fatty acid metabolism. VITAMIN B12 ..... concentrations of homocysteine, folate and vitamin B12 in ... and folic acid: a cross-sectional study in patients with type 2 ... pregnant women with polycystic ovary syndrome.

  4. 4-ethylphenyl-cobalamin impairs tissue uptake of vitamin B12 and causes vitamin B12 deficiency in mice

    DEFF Research Database (Denmark)

    Mutti, Elena; Ruetz, Markus; Birn, Henrik

    2013-01-01

    Coβ-4-ethylphenyl-cob(III) alamin (EtPhCbl) is an organometallic analogue of vitamin B12 (CNCbl) which binds to transcobalamin (TC), a plasma protein that facilitates the cellular uptake of cobalamin (Cbl). In vitro assays with key enzymes do not convert EtPhCbl to the active coenzyme forms of Cbl...... treated with EtPhCbl (1.01±0.12 µmol/L) compared to controls (0.30±0.02 µmol/L) and CNCbl (0.29±0.01 µmol/L) treated animals. The same pattern was observed for tHcy. Plasma total Cbl concentration was higher in animals treated with EtPhCbl (128.82±1.87 nmol/L) than in CNCbl treated animals (87.......64±0.93 nmol/L). However, the organ levels of total Cbl were significantly lower in animals treated with EtPhCbl compared to CNCbl treated animals or controls, notably in the liver (157.07±8.56 pmol/g vs. 603.85±20.02 pmol/g, and 443.09±12.32 pmol/g, respectively). Differences between the three groups...

  5. Efeito da corticotropina sobre a absorção de vitamina B12 na mielose funicular

    Directory of Open Access Journals (Sweden)

    Horacio M. Canelas

    1965-06-01

    Full Text Available Foi estudada a absorção de vitamina B12 em 9 casos de mielose funicular antes e após a administração de ACTH por via intravenosa em um esquema terapêutico com duração variável entre 19 e 43 dias. Em 7 casos foi verificado aumento da absorção. A diferença média de modificação no teste de excreção urinaria de vitamina B12 radioativa situou-se próximo do nível de significancia estatística. Este resultado reforça a indicação do emprego de corticotropina na mielose funicular, pois o hormônio irá atuar tanto sobre o componente alérgico do prccesso desmielinizante, quanto sobre a carência de vitamina B12 resultante do déficit de absorção. Embora o material aqui analisado seja muito pequeno para garantir uma conclusão definitiva, nossos resultados demonstram que, provavelmente, o ACTH age sobre a absorção da vitamina B12 através da mucosa intestinal, e não mediante o aumento de secreção do fator intrínseco ou a mobilização dos depósitos dessa vitamina. In order to study a possible mobilizing effect of ACTH on the radioactive vitamin B12 stores, the intervals between the last urinary excretion test and the test after completion of treatment were analyzed (Table 1. It is easily noticed that in the 7 cases with increase of vitamin B12 absorption these periods were the most varied, lasting from 9 to 62 days. And also in the 2 cases with decrease of absorption the intervals were very dissimilar, namely 15 and 56 days. So, it seems that this effect of ACTH did not play a significant role in the results. Likewise, the time elapsed between the completion of treatment and the repetition of the Schilling's test had no apparent relationship with the results.

  6. The distribution of total vitamin b12 holotranscobalamin and the active vitamin b12 fraction in the first 5 weeks postpartum

    NARCIS (Netherlands)

    van der Woude, D.A.A.; Pijnenborg, J.M.A.; de Vries, J.; van Wijk, E.M.

    2018-01-01

    Introduction Total vitamin B12 levels decrease significantly during pregnancy and recover to normal values within 8-week postpartum. Holotranscobalamin (holoTC) reflects the active part of vitamin B12 and has been shown to remain constant during pregnancy and postpartum. A mechanism of

  7. Assessment of Serum Vitamin B12 Concentrations in Patients with a ...

    African Journals Online (AJOL)

    Serum vitamin B12 levels were obtained preoperatively and every 6 months postoperatively. All patients received 100 microgram of vitamin B-12 twice yearly. Follow up ranged from 3-10 years. Results All 16 patients included in the study had a normal concentration of serum vitamin B12 preoperatively with a range of ...

  8. Prevalence of Vitamin B12 deficiency in patients of type 2 diabetes ...

    African Journals Online (AJOL)

    Conclusion: Our study demonstrated significantly high prevalence of vitamin B12 deficiency in patients treated with metformin with significant effect of dose and duration of metformin use on B12 levels. Physicians must recognize this important fact and screen diabetics on metformin therapy for underlying B12 deficiency.

  9. High intersubband absorption in long-wave quantum well infrared photodetector based on waveguide resonance

    Science.gov (United States)

    Zheng, Yuanliao; Chen, Pingping; Ding, Jiayi; Yang, Heming; Nie, Xiaofei; Zhou, Xiaohao; Chen, Xiaoshuang; Lu, Wei

    2018-06-01

    A hybrid structure consisting of periodic gold stripes and an overlaying gold film has been proposed as the optical coupler of a long-wave quantum well infrared photodetector. Absorption spectra and field distributions of the structure at back-side normal incidence are calculated by the finite difference time-domain method. The results indicate that the intersubband absorption can be greatly enhanced based on the waveguide resonance as well as the surface plasmon polariton (SPP) mode. With the optimized structural parameters of the periodic gold stripes, the maximal intersubband absorption can exceed 80%, which is much higher than the SPP-enhanced intersubband absorption (the one of the standard device. The relationship between the structural parameters and the waveguide resonant wavelength is derived. Other advantages of the efficient optical coupling based on waveguide resonance are also discussed.

  10. Solid-phase radioimmunoassay for vitamin B12 in serum, with use of radioiodinated tyrosine methyl ester of vitamin B12

    International Nuclear Information System (INIS)

    Endres, D.B.; Painter, K.; Niswender, G.D.

    1978-01-01

    Although radioassays for vitamin B 12 with use of any of several binding proteins have been available for many years, a radioimmunoassay for B 12 has not been reported. We describe here such a radioimmunoassay, incorporating, for the first time, a radioiodinated tyrosine methyl ester of B 12 as the radioactive tracer. Polypropylene tubes are coated with antiserum raised in a rabbit against B 12 /bovine serum albumin to simplify the separation of bound and free radioactivity. Factors affecting the preparation of coated tubes are described. The assay is accurate, sensitive, precise, and specific for vitamin B 12 . Accuracy of the assay is unaffected by the presence of denatured protein. The advantages of this radioimmunoassay over conventional radioassays are discussed

  11. Vitamin B12 deficiency in diabetic subjects taking metformin: A cross sectional study in a Lebanese cohort

    Directory of Open Access Journals (Sweden)

    Joyce Zalaket

    2018-03-01

    Based on our results, we strongly recommend the routine screening of subjects with T2D on metformin for vitamin B12 deficiency due to its high prevalence and the significant clinical effects it may result in. Furthermore, we recommend, based on our data, to start treating those subjects once a borderline or low level is detected.

  12. Brucella melitensis VirB12 recombinant protein is a potential marker for serodiagnosis of human brucellosis.

    Science.gov (United States)

    Mirkalantari, Shiva; Zarnani, Amir-Hassan; Nazari, Mahboobeh; Irajian, Gholam Reza; Amirmozafari, Nour

    2017-03-03

    The numerous drawbacks of current serological tests for diagnosis of brucellosis which mainly results from cross reactivity with LPS from other gram-negative bacteria have generated an increasing interest to find more specific non-LPS antigens. Previous studies had indicated that Brucella VirB12 protein, a cell surface protein and component of type IV secretion system, induces antibody response during animal infection. However, this protein has not yet been tested as a serological diagnostic marker in human brucellosis. Recombinant VirB12 protein was prepared and evaluated the efficacy of it in an indirect enzyme-linked immunosorbent assay (ELISA) for brucellosis with sera collected from different region of Iran and the results were compared with a commercial ELISA kit. Sera from human brucellosis patients strongly reacted to the purified recombinant VirB12. The sensitivity, specificity, accuracy, negative predictive value and positive predictive value of recombinant VirB12-based ELISA related to the commercial-ELISA method were 87.8, 94, 90, 80 and 96.6% respectively. We concluded that antigenic VirB12 have a property value that can be considered as a candidate for using in serodiagnostic tests for human brucellosis.

  13. [Extracting THz absorption coefficient spectrum based on accurate determination of sample thickness].

    Science.gov (United States)

    Li, Zhi; Zhang, Zhao-hui; Zhao, Xiao-yan; Su, Hai-xia; Yan, Fang

    2012-04-01

    Extracting absorption spectrum in THz band is one of the important aspects in THz applications. Sample's absorption coefficient has a complex nonlinear relationship with its thickness. However, as it is not convenient to measure the thickness directly, absorption spectrum is usually determined incorrectly. Based on the method proposed by Duvillaret which was used to precisely determine the thickness of LiNbO3, the approach to measuring the absorption coefficient spectra of glutamine and histidine in frequency range from 0.3 to 2.6 THz(1 THz = 10(12) Hz) was improved in this paper. In order to validate the correctness of this absorption spectrum, we designed a series of experiments to compare the linearity of absorption coefficient belonging to one kind amino acid in different concentrations. The results indicate that as agreed by Lambert-Beer's Law, absorption coefficient spectrum of amino acid from the improved algorithm performs better linearity with its concentration than that from the common algorithm, which can be the basis of quantitative analysis in further researches.

  14. A comparative investigation on absorption performances of three expanded graphite-based complex materials for toluene

    International Nuclear Information System (INIS)

    Li Shande; Tian Shuanghong; Feng Yunfeng; Lei Jiajia; Wang, Piaopiao; Xiong Ya

    2010-01-01

    Three kinds of expanded graphite-based complex materials were prepared to absorb toluene by dispersing plant oil, animal oil and mineral oil on the surface of expanded graphite, respectively. These complex materials were characterized by scanning electronic micrograph, contact angle meter and Brunauer-Emmett-Teller surface area. And their absorption capacities for toluene were comparatively investigated. The results showed that the surfaces of the three types of sorbents were very hydrophobic and nonporous, but they all had excellent absorption capacities for toluene. And their absorption capacities were proportional to the toluene concentration in streams and decreased differently with increasing the absorption temperature. It was noteworthy that the absorption capacities varied with the unsaturated degree of the complex materials and kept unchanged under different relative humidities of streams. Moreover, the regeneration experiments showed that after 15-run regeneration the absorption capacities of expanded graphite modified by mineral oil almost kept unchanged, while that of expanded graphite loaded plant oil and animal oil dropped by 157 and 93.6 mg g -1 , respectively. The losses of their absorption capacities were ascribed to the destruction of their unsaturated carbon bounds.

  15. Clinical value of serum vitamin B12 and folate in cerebrovascular disease

    International Nuclear Information System (INIS)

    Zhan Hao; Zhang Yongxue

    2002-01-01

    To study the clinical value of serum vitamin B 12 and folate in cerebrovascular disease, the concentration of serum vitamin B 12 and folate in 32 patients with cerebrovascular disease was measured by radioimmunoassay. The results showed that the changes in folate in all groups were not significant. The content of vitamin B 12 in multi-infarct dementia was markedly lower than that in cerebral infarction and cerebral hemorrhage. Moreover, the level of vitamin B 12 was lower in paralytic patients with muscular strength of grade 0-III. It can be concluded that serum vitamin B 12 level had association with intelligent disorder and paralytic degree

  16. Tunable THz wave absorption by graphene-assisted plasmonic metasurfaces based on metallic split ring resonators

    International Nuclear Information System (INIS)

    Ahmadivand, Arash; Sinha, Raju; Karabiyik, Mustafa; Vabbina, Phani Kiran; Gerislioglu, Burak; Kaya, Serkan; Pala, Nezih

    2017-01-01

    Graphene plasmonics has been introduced as a novel platform to design various nano- and microstructures to function in a wide range of spectrum from optical to THz frequencies. Herein, we propose a tunable plasmonic metamaterial in the THz regime by using metallic (silver) concentric microscale split ring resonator arrays on a multilayer metasurface composed of silica and silicon layers. We obtained an absorption percentage of 47.9% including two strong Fano resonant dips in THz regime for the purely plasmonic metamaterial without graphene layer. Considering the data of an atomic graphene sheet (with the thickness of ~0.35 nm) in both analytical and experimental regimes obtained by prior works, we employed a graphene layer under concentric split ring resonator arrays and above the multilayer metasurface to enhance the absorption ratio in THz bandwidth. Our numerical and analytical results proved that the presence of a thin graphene layer enhances the absorption coefficient of MM to 64.35%, at the highest peak in absorption profile that corresponds to the Fano dip position. We also have shown that changing the intrinsic characteristics of graphene sheet leads to shifts in the position of Fano dips and variations in the absorption efficiency. The maximum percentage of absorption (~67%) was obtained for graphene-based MM with graphene layer with dissipative loss factor of 1477 Ω. Employing the antisymmetric feature of the split ring resonators, the proposed graphene-based metamaterial with strong polarization dependency is highly sensitive to the polarization angle of the incident THz beam.

  17. Electronic properties and bulk moduli of novel boron nitride polymorphs: hyperdiamond B12N12 and the simple cubic B24N24, B12N12 fulborenites

    International Nuclear Information System (INIS)

    Pokrivnyj, V.V.; Bekenev, V.L.

    2006-01-01

    Equation of states, energy band structure, electronic density of states, and bulk moduli of the boron nitride fulborenite crystals: B 12 N 12 with a diamond lattice and B 24 N 24 , B 12 N 12 with a simple cubic lattice have been calculated for the first time by FLAPW method. Calculated parameters of these compounds are as follows: equilibrium lattice parameter, the length of B-N bond, the number of atoms per conventional cell, density, bulk modulus, band gap. Hyperdiamond B 12 N 12 is shown to have the record bulk modulus B 0 = 658 GPa [ru

  18. Folato, vitamina B12 e ferritina sérica e defeitos do tubo neural Folate, vitamin B12, serum ferritin and defects of the neural tube

    Directory of Open Access Journals (Sweden)

    Gizele Thame

    1998-09-01

    Full Text Available Objetivo: verificar os níveis de folatos, vitamina B12 e ferritina em pacientes cujos fetos apresentaram defeitos de tubo neural (DTN. O folato sangüíneo e a vitamina B12 atuam como cofatores para as enzimas envolvidas na biossíntese do DNA. A interrupção deste processo pode impedir o fechamento do tubo neural. A suplementação vitamínica contendo folato pode reduzir as taxas de ocorrência de defeitos de tubo neural, embora exista a preocupação de que esta prevenção possa mascarar a deficiência de vitamina B12. Métodos: dosagens de vitamina B12 e ferritina pelo método de enzimaimunoensaio com micropartículas e a dosagens de ácido fólico pelo método de captura iônica (IMx ABBOTT. Resultados: a porcentagem de gestantes com deficiência de vitamina B12 (níveis séricos Purpose: to determine folate, vitamin B12 and ferritin levels in patients whose fetuses presented neural-tube defects (NTD. Blood folate and vitamin B12 act as cofactors of enzymes involved in DNA biosynthesis. Interruption of this process may block neural-tube closing. Vitamin supplementation with folate may reduce occurrence rates and recurrence of NTD, although there is concern about the fact that this prevention may mask vitamin B12 deficiency. Methods: vitamin B12 and ferritin determinations by enzyme immunoassay with microparticles and folic acid determination using the ion capture method (IMx ABBOTT. Results: the percentage of pregnant women with vitamin B12 deficirncy (serum levels < 150 pg/ml was 11.8%. There was no case of folate deficiency (serum levels < 3.0 ng/ml and prevalence of pregnant women with iron store deficiency was 47.1% (serum levels < ng/mg. Conclusions: occording to the results obtained in this study (prevalence of 11.8% of vitamin B12 and 0% of folate deficient pregnant women we suggest that supplementation should be administered after serum vitamin B12 determination.

  19. Vitamin B12 supplementation during pregnancy and postpartum improves B12 status of both mothers and infants but vaccine response in mothers only: a randomized clinical trial in Bangladesh

    Science.gov (United States)

    Purpose Poor vitamin B12 (B12) status is associated with adverse outcomes in pregnancy and infancy. Little is known about effects of B12 supplementation on immune function. The present study aimed to evaluate effects of pre- and postnatal B12 supplementation on biomarkers of B12 status and vaccine-s...

  20. Correlation between serum vitamin B12 level and peripheral neuropathy in atrophic gastritis.

    Science.gov (United States)

    Yang, Guo-Tao; Zhao, Hong-Ying; Kong, Yu; Sun, Ning-Ning; Dong, Ai-Qin

    2018-03-28

    To explore the correlation between serum vitamin B12 level and peripheral neuropathy in patients with chronic atrophic gastritis (CAG). A total of 593 patients diagnosed with chronic gastritis by gastroscopy and pathological examination from September 2013 to September 2016 were selected for this study. The age of these patients ranged within 18- to 75-years-old. Blood pressure, height and weight were measured in each patient, and the body mass index value was calculated. Furthermore, gastric acid, serum gastrin, serum vitamin and serum creatinine tests were performed, and peripheral nerve conduction velocity and Helicobacter pylori ( H. pylori ) were detected. In addition, the type of gastritis was determined by gastroscopy. The above factors were used as independent variables to analyze chronic gastritis with peripheral neuropathy and vitamin B12 deficiency risk factors, and to analyze the relationship between vitamin B12 levels and peripheral nerve conduction velocity. In addition, in the treatment of CAG on the basis of vitamin B12, patients with peripheral neuropathy were observed. Age, H. pylori infection, CAG, vitamin B9 and vitamin B12 were risk factors for the occurrence of peripheral nerve degeneration. Furthermore, CAG and H. pylori infection were risk factors for chronic gastritis associated with vitamin B12 deficiency. Serum vitamin B12 level was positively correlated with sensory nerve conduction velocity in the tibial nerve ( R = 0.463). After vitamin B12 supplementation, patients with peripheral neuropathy improved. Serum vitamin B12 levels in patients with chronic gastritis significantly decreased, and the occurrence of peripheral neuropathy had a certain correlation. CAG and H. pylori infection are risk factors for vitamin B12 deficiency and peripheral neuropathy. When treating CAG, vitamin B12 supplementation can significantly reduce peripheral nervous system lesions. Therefore, the occurrence of peripheral neuropathy associated with vitamin B12

  1. Genetic Variation in Vitamin B-12 Content of Bovine Milk and Its Association with SNP along the Bovine Genome

    NARCIS (Netherlands)

    Rutten, M.J.M.; Bouwman, A.C.; Sprong, R.C.; Arendonk, van J.A.M.; Visker, M.H.P.W.

    2013-01-01

    Vitamin B-12 (also called cobalamin) is essential for human health and current intake levels of vitamin B-12 are considered to be too low. Natural enrichment of the vitamin B-12 content in milk, an important dietary source of vitamin B-12, may help to increase vitamin B-12 intake. Natural enrichment

  2. Pengaruh asupan Fe, vitamin A, vitamin B12, dan vitamin C terhadap kadar hemoglobin pada remaja vegan

    Directory of Open Access Journals (Sweden)

    Damayanti Siallagan

    2016-10-01

    Full Text Available Background: Vegan has become a diet that started to be many people's choice. Low intake of iron and vitamin B12 is factors that can cause anemia in vegan. On the other side vegans often consume vegetables and fruits that contained high of vitamin A and vitamin C which helps the absorption of iron, that can help prevent anemia. Objective: The purpose of the research know the effect of the intake of iron, vitamin A, vitamin B12, vitamin C on hemoglobin (Hblevels in young Buddhist vegan Pusdiklat Maitreyawira. Method: This research uses cross-sectional design. The population in this study are all adolescent vegan in the Buddhist Pusdiklat Maitreyawira. Samples in this study were 31 peoples. Independent variable is an intake of iron, vitamin A, vitamin B12, and vitamin C was obtained by SQ-FFQ, while the dependent variable was Hb with hemoglobin testing system quick-check set. Analysis of the data in this study using Pearson correlation and multiple linear regression. Results: There is a relationship intake of iron (p=0,000, vitamin B12 (p=0,037, and vitamin C (p=0,000 to Hb level of adolescent vegan in Buddhist Pusdiklat Maitreyawira, there is no relationship intake of vitamin A with a Hb level of adolescent vegan (p=0,220. The result of multivariate analysis using multiple regression analysis of the variables that most influence haemoglobin levels of adolescent vegan are the intake of iron and vitamin C. Each increase of 1 mg Fe intake will increase the Hb concentration as much as 0.013 g/dl and increase of 1 mg of vitamin C intake will increase Hb levels as much as 0.002 g/dl. Conclusion: Iron and vitamin C intake is the most influence factors to hemoglobin levels of adolescent vegan in Buddhist Pusdiklat Maitreyawira.

  3. Genetic disorders of vitamin B12 metabolism: eight complementation groups – eight genes

    Science.gov (United States)

    Froese, D. Sean; Gravel, Roy A.

    2010-01-01

    Vitamin B12 (cobalamin, Cbl) is an essential nutrient in human metabolism. Genetic diseases of vitamin B12 utilisation constitute an important fraction of inherited newborn disease. Functionally, B12 is the cofactor for methionine synthase and methylmalonyl CoA mutase. To function as a cofactor, B12 must be metabolised through a complex pathway that modifies its structure and takes it through subcellular compartments of the cell. Through the study of inherited disorders of vitamin B12 utilisation, the genes for eight complementation groups have been identified, leading to the determination of the general structure of vitamin B12 processing and providing methods for carrier testing, prenatal diagnosis and approaches to treatment. PMID:21114891

  4. Design and synthesis of hyperstructured molecules based on cyclophosphazene core for multiphoton absorption

    International Nuclear Information System (INIS)

    Naik, K. Praveen Kumar; Sreeramulu, V.; Ramya, E.; Muralidharan, K.; Rao, D. Narayana

    2016-01-01

    Cyclophosphazene based hyperstructured molecules were synthesized through simple nucleophilic substitution reactions. All these molecules were characterized by multinuclear NMR, MALDI and HRMS spectral data. Third order nonlinear optical properties of the hyperstructured molecules were measured using Z-scan technique with 532 nm, picosecond (ps) laser and 800 nm, femtosecond (fs) laser pulses. The molecules showed reverse saturable absorption on excitation at both 532 nm and 800 nm, which could be attributed to the two-photon absorption (2 PA) and three-photon absorption (3 PA), respectively. The 2 PA and 3 PA cross section values exhibited by the molecules based on cyclophosphazene are as high as 527 GM and 1.86 × 10"−"7"6 cm"−"6 s"2 photon"−"1, respectively. The 2PA, 3PA coefficients and optical limiting properties make them suitable candidates for nonlinear optical devices in the visible and near IR range. - Graphical abstract: The hyperstructured molecules based on cyclophosphazene core were synthesized and used for multiphoton absorption. Open aperture Z-scan curves of hyper structured molecules at the excitation of (a) picosecond laser and (b) femtosecond laser representing multiphoton absorption properties are reported. - Highlights: • Two hyperstructured molecules based on cyclophosphazene core are designed for multiphoton absorption. • NLO properties are measured using Z-scan technique at 532 nm and 800 nm wavelengths. • The molecules were tested for the optical limiting applications at 532 nm and 800 nm laser pulses.

  5. Design and synthesis of hyperstructured molecules based on cyclophosphazene core for multiphoton absorption

    Energy Technology Data Exchange (ETDEWEB)

    Naik, K. Praveen Kumar [School of Chemistry, University of Hyderabad, Hyderabad 500046 India (India); Sreeramulu, V. [School of Physics, University of Hyderabad, Hyderabad 500046 India (India); CNR-IFN CSMFO Laboratory, Via alla Cascata, 56/C Povo, Trento (Italy); Ramya, E. [School of Physics, University of Hyderabad, Hyderabad 500046 India (India); Muralidharan, K., E-mail: murali@uohyd.ac.in [School of Chemistry, University of Hyderabad, Hyderabad 500046 India (India); Rao, D. Narayana [School of Physics, University of Hyderabad, Hyderabad 500046 India (India)

    2016-09-01

    Cyclophosphazene based hyperstructured molecules were synthesized through simple nucleophilic substitution reactions. All these molecules were characterized by multinuclear NMR, MALDI and HRMS spectral data. Third order nonlinear optical properties of the hyperstructured molecules were measured using Z-scan technique with 532 nm, picosecond (ps) laser and 800 nm, femtosecond (fs) laser pulses. The molecules showed reverse saturable absorption on excitation at both 532 nm and 800 nm, which could be attributed to the two-photon absorption (2 PA) and three-photon absorption (3 PA), respectively. The 2 PA and 3 PA cross section values exhibited by the molecules based on cyclophosphazene are as high as 527 GM and 1.86 × 10{sup −76} cm{sup −6} s{sup 2} photon{sup −1}, respectively. The 2PA, 3PA coefficients and optical limiting properties make them suitable candidates for nonlinear optical devices in the visible and near IR range. - Graphical abstract: The hyperstructured molecules based on cyclophosphazene core were synthesized and used for multiphoton absorption. Open aperture Z-scan curves of hyper structured molecules at the excitation of (a) picosecond laser and (b) femtosecond laser representing multiphoton absorption properties are reported. - Highlights: • Two hyperstructured molecules based on cyclophosphazene core are designed for multiphoton absorption. • NLO properties are measured using Z-scan technique at 532 nm and 800 nm wavelengths. • The molecules were tested for the optical limiting applications at 532 nm and 800 nm laser pulses.

  6. Purification of rat intestinal receptor for intrinsic factor-vitamin B12 complex

    International Nuclear Information System (INIS)

    Yamada, Shoji; Itaya, Harutaka; Nakazawa, Osamu; Fukuda, Morimichi.

    1977-01-01

    The intrinsic factor (IF) in a rat gastric mucosal extract was bound efficiently to vitamin B 12 -sepharose without significant change in its nature to produce IF-vitamin B 12 -sepharose. The purification of the intestinal receptor for the IF-vitamin B 12 complex was performed by the affinity chromatography using the IF-vitamin B 12 -sepharose as the affinity adsorbent. As a result of admixing the gastric mucosal extract sample with B 12 -sepharose while stirring for 4 hours, the adsorption was performed without any break through. Further, it was recognized that the B 12 -bound protein purified by the affinity chromatography using B 12 -sepharose was not much changed as compared with that before purification. Furthermore, it was recognized that IF-B 12 -sepharose was able to be made by binding IF with B 12 -sepharose which was made by coupling B 12 with the market-available AH-sepharose. The IF-B 12 -sepharose was washed with buffer solution, and then was loaded with the small intestine mucosal extract. Thereafter, the receptor was eluted by making di-valent cation inert with the buffer solution. After the removal of EDTA in the eluted solution by dialysis, the activity of the receptor was measured. 48.5% of the receptor activity loaded was recovered by the elution with EDTA. The specific activity of the receptor represented by the final amount of B 12 (pg)/the amount of protein (mg) in the purified substance was 335 folds of the original activity. (Iwakiri, K.)

  7. Atopy, asthma, and lung function in relation to folate and vitamin B(12) in adults

    DEFF Research Database (Denmark)

    Thuesen, B H; Husemoen, L L N; Ovesen, L

    2010-01-01

    Recent studies suggested low serum folate and impaired folate metabolism as potential risk factors for development of asthma and atopic disease, but the results are inconsistent. The aim of this study was to investigate the relations of markers of folate and vitamin B12 (B12) deficiency with diff......Recent studies suggested low serum folate and impaired folate metabolism as potential risk factors for development of asthma and atopic disease, but the results are inconsistent. The aim of this study was to investigate the relations of markers of folate and vitamin B12 (B12) deficiency...

  8. Synchrotron radiation based Mössbauer absorption spectroscopy of various nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Ryo, E-mail: masudar@rri.kyoto-u.ac.jp; Kobayashi, Yasuhiro; Kitao, Shinji; Kurokuzu, Masayuki; Saito, Makina [Kyoto University, Research Reactor Institute (Japan); Yoda, Yoshitaka [Japan Synchrotron Radiation Research Institute, Resarch and Utilization Division (Japan); Mitsui, Takaya [Japan Atomic Energy Agency, Condensed Matter Science Division, Sector of Nuclear Science Research (Japan); Seto, Makoto [Kyoto University, Research Reactor Institute (Japan)

    2016-12-15

    Synchrotron-radiation (SR) based Mössbauer absorption spectroscopy of various nuclides is reviewed. The details of the measuring system and analysis method are described. Especially, the following two advantages of the current system are described: the detection of internal conversion electrons and the close distance between the energy standard scatterer and the detector. Both of these advantages yield the enhancement of the counting rate and reduction of the measuring time. Furthermore, SR-based Mössbauer absorption spectroscopy of {sup 40}K, {sup 151}Eu, and {sup 174}Yb is introduced to show the wide applicability of this method. In addition to these three nuclides, SR-based Mössbauer absorption spectroscopy of {sup 61}Ni, {sup 73}Ge, {sup 119}Sn, {sup 125}Te, {sup 127}I, {sup 149}Sm, and {sup 189}Os has been performed. We continue to develop the method to increase available nuclides and to increase its ease of use. The complementary relation between the time-domain method using SR, such as nuclear forward scattering and the energy-domain methods such as SR-based Mössbauer absorption spectroscopy is also noted.

  9. Diffuse reflectance relations based on diffusion dipole theory for large absorption and reduced scattering

    NARCIS (Netherlands)

    Bremmer, Rolf H.; van Gemert, Martin J. C.; Faber, Dirk J.; van Leeuwen, Ton G.; Aalders, Maurice C. G.

    2013-01-01

    Diffuse reflectance spectra are used to determine the optical properties of biological samples. In medicine and forensic science, the turbid objects under study often possess large absorption and/or scattering properties. However, data analysis is frequently based on the diffusion approximation to

  10. Tungsten determination in heat resistant nickel-base-alloys by the method of atomic absorption

    International Nuclear Information System (INIS)

    Gregorczyk, S.; Wycislik, A.

    1980-01-01

    A method of atomic absorption was developed. It allows for the tungsten to be determined in heatresistant nickel-base-alloys within the range 0.01 to 7%. It consists in precipitating tungsten acid in the presence of alkaloids with its following decomposition by hydrofluoric acid in the teflon bomb. (author)

  11. A new in vitro lipid digestion - in vivo absorption model to evaluate the mechanisms of drug absorption from lipid-based formulations.

    Science.gov (United States)

    Crum, Matthew F; Trevaskis, Natalie L; Williams, Hywel D; Pouton, Colin W; Porter, Christopher J H

    2016-04-01

    In vitro lipid digestion models are commonly used to screen lipid-based formulations (LBF), but in vitro-in vivo correlations are in some cases unsuccessful. Here we enhance the scope of the lipid digestion test by incorporating an absorption 'sink' into the experimental model. An in vitro model of lipid digestion was coupled directly to a single pass in situ intestinal perfusion experiment in an anaesthetised rat. The model allowed simultaneous real-time analysis of the digestion and absorption of LBFs of fenofibrate and was employed to evaluate the influence of formulation digestion, supersaturation and precipitation on drug absorption. Formulations containing higher quantities of co-solvent and surfactant resulted in higher supersaturation and more rapid drug precipitation in vitro when compared to those containing higher quantities of lipid. In contrast, when the same formulations were examined using the coupled in vitro lipid digestion - in vivo absorption model, drug flux into the mesenteric vein was similar regardless of in vitro formulation performance. For some drugs, simple in vitro lipid digestion models may underestimate the potential for absorption from LBFs. Consistent with recent in vivo studies, drug absorption for rapidly absorbed drugs such as fenofibrate may occur even when drug precipitation is apparent during in vitro digestion.

  12. Vitamin B(12) Immunoassay on Roche Elecsys 2010: Effects of High Excess Concentration of Serum Vitamin B(12) in CKD Patients on Parenteral Administration.

    Science.gov (United States)

    Basu, Surupa; Chaudhuri, Subimal

    2011-10-01

    Vitamin B(12) being water soluble is excreted in the urine when administered in excess. The probability of finding an abnormally excess serum concentration would be almost surreal. We report a peculiar clinical situation that may impact the vitamin B(12) immunoassay on the Roche Elecsys 2010 due to excess analyte concentration. In separate episodes (Feb and June 2010), the Biochemistry laboratory of a tertiary-care hospital, Kolkata, India, encountered two critically ill patients with background chronic kidney disease (CKD), low urine output, and on cyanocoabalamin supplementation, who had serum vitamin B(12) concentrations far exceeding expected values; even post dialysis. The B(12) assays (pmol/l) were performed using electrochemiluminiscence immunoassay on Roche Elecsys 2010, the assay validity confirmed by concomitant quality control runs. The immunoassays failed to deliver results, flagged with "signal level below limit". Biotin therapy was ruled out as a possible interferent. In the first episode, re-assay of a repeat draw yielded same outcome; outsourcing on Immulite provided concentration of >738 pmol/l. Serial dilution gave result of >29520 pmol/l on Elecsys 2010. In the second, we gained from past experience. Vitamin B(12) concentration >59040 pmol/l was conveyed to the treating nephrologist the very day. The B(12) immunoassay on the Elecsys 2010 employs sequential incubation steps for competitive binding that is compromised in the event of abnormally excess B(12) concentration in patient sera akin to the prozone effect. This knowledge may be beneficial while assaying sera of CKD patients to avoid financial loss due unnecessary repeats and delay in turnaround time.

  13. Effect of various absorption enhancers based on tight junctions on the intestinal absorption of forsythoside A in Shuang-Huang-Lian, application to its antivirus activity.

    Science.gov (United States)

    Zhou, Wei; Zhu, Xuan Xuan; Yin, Ai Ling; Cai, Bao Chang; Wang, Hai Dan; Di, Liuqing; Shan, Jin Jun

    2014-01-01

    Forsythoside A (FTA), one of the main active ingredients in Shuang-Huang-Lian (SHL), possesses strong antibacterial, antioxidant and antiviral effects, and its pharmacological effects was higher than that of other ingredients, but the absolute bioavailability orally was approximately 0.72%, which was significantly low, influencing clinical efficacies of its oral preparations seriously. In vitro Caco-2 cell and in vivo pharmacokinetics study were simultaneously performed to investigate the effects of absorption enhancers based on tight junctions: sodium caprate and water-soluble chitosan on the intestinal absorption of FTA, and the eventual mucosal epithelial damage resulted from absorption enhancers was evaluated by MTT test and morphology observation, respectively. The pharmacological effects such as antivirus activity improvement by absorption enhancers were verified by MDCK damage inhibition rate after influenza virus propagation. The observations from in vitro Caco-2 cell showed that the absorption of FTA in SHL could be improved by absorption enhancers. Meanwhile, the absorption enhancing effect of water-soluble chitosan may be almost saturable up to 0.0032% (w/v), and sodium caprate at concentrations up to 0.64 mg/mL was safe, but water-soluble chitosan at different concentrations was all safe for these cells. In pharmacokinetics study, water-soluble chitosan at dosage of 50 mg/kg improved the bioavailability of FTA in SHL to the greatest extent, and was safe for gastrointestine from morphological observation. Besides, treatment with SHL with water-soluble chitosan at dosage of 50 mg/kg prevented MDCK damage after influenza virus propagation better significantly than that of control. Water-soluble chitosan at dosage of 50 mg/kg might be safe and effective absorption enhancer for improving the bioavailability of FTA and the antivirus activity in vitro in SHL.

  14. Study of plasma-based stable and ultra-wideband electromagnetic wave absorption for stealth application

    Science.gov (United States)

    Xuyang, CHEN; Fangfang, SHEN; Yanming, LIU; Wei, AI; Xiaoping, LI

    2018-06-01

    A plasma-based stable, ultra-wideband electromagnetic (EM) wave absorber structure is studied in this paper for stealth applications. The stability is maintained by a multi-layer structure with several plasma layers and dielectric layers distributed alternately. The plasma in each plasma layer is designed to be uniform, whereas it has a discrete nonuniform distribution from the overall view of the structure. The nonuniform distribution of the plasma is the key to obtaining ultra-wideband wave absorption. A discrete Epstein distribution model is put forward to constrain the nonuniform electron density of the plasma layers, by which the wave absorption range is extended to the ultra-wideband. Then, the scattering matrix method (SMM) is employed to analyze the electromagnetic reflection and absorption of the absorber structure. In the simulation, the validation of the proposed structure and model in ultra-wideband EM wave absorption is first illustrated by comparing the nonuniform plasma model with the uniform case. Then, the influence of various parameters on the EM wave reflection of the plasma are simulated and analyzed in detail, verifying the EM wave absorption performance of the absorber. The proposed structure and model are expected to be superior in some realistic applications, such as supersonic aircraft.

  15. Note: A flexible light emitting diode-based broadband transient-absorption spectrometer

    Science.gov (United States)

    Gottlieb, Sean M.; Corley, Scott C.; Madsen, Dorte; Larsen, Delmar S.

    2012-05-01

    This Note presents a simple and flexible ns-to-ms transient absorption spectrometer based on pulsed light emitting diode (LED) technology that can be incorporated into existing ultrafast transient absorption spectrometers or operate as a stand-alone instrument with fixed-wavelength laser sources. The LED probe pulses from this instrument exhibit excellent stability (˜0.5%) and are capable of producing high signal-to-noise long-time (>100 ns) transient absorption signals either in a broadband multiplexed (spanning 250 nm) or in tunable narrowband (20 ns) operation. The utility of the instrument is demonstrated by measuring the photoinduced ns-to-ms photodynamics of the red/green absorbing fourth GMP phosphodiesterase/adenylyl cyclase/FhlA domain of the NpR6012 locus of the nitrogen-fixing cyanobacterium Nostoc punctiforme.

  16. The Singer's and the Clinician's Perspective on Vitamin B12 Treatment for Vocal Benefits.

    Science.gov (United States)

    Shoffel-Havakuk, Hagit; Lava, Christian X; Hapner, Edie R; O'Dell, Karla; Reder, Lindsay; Johns, Michael M

    2018-01-03

    There is a belief among vocalists that there are voice benefits from vitamin B 12 treatment. Yet there are no previous reports regarding vitamin B 12 effects on voice. To assess the prevalence of vitamin B 12 use among singers and their beliefs regarding vitamin B 12 therapy. Anonymous online survey administered to singers, singing-teachers, speech-language pathologists, and laryngologists. A total of 192 participants completed the surveys; 128 singers (68 singing-teachers, 30 speech-language pathologists) and 64 laryngologists. Among singers, 12% have perceived voice benefits from vitamin B 12 treatment taken for any reason. Four percent used vitamin B 12 for voice benefits; all perceived voice benefits as a result. The leading voice benefits were improved stamina, reduced effort, confidence, and control. Nineteen percent of the singers would recommend vitamin B 12 treatment to a friend; 15% of the singing-teachers would recommend it to a student. Among laryngologists, 33% been asked by a singer to prescribe vitamin B 12 for voice benefits; 9% have prescribed it in the past. Yet only 3% would you recommend it to a patient. When asked "Do you believe vitamin B 12 therapy improves vocal performance?" 31% of the singers responded "Yes," compared with none in the laryngologists. When asked "Do you think the singing community believes vitamin B 12 therapy improves vocal performance?" 26% of the singers responded "Yes," compared with 53% of the laryngologists (P = 0.0002). There is a discrepancy between the singers' and the laryngologists' beliefs regarding vocal benefits perceived by vitamin B 12 . Blinded randomized trials are required to verify or refute this belief. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  17. Elevated Plasma Vitamin B12 Levels as a Marker for Cancer

    DEFF Research Database (Denmark)

    Arendt, Johan Frederik Berg; Pedersen, Lars; Nexo, Ebba

    2013-01-01

    ) with 95% confidence intervals (CIs), stratified by plasma Cbl levels. All statistical tests were two-sided. RESULTS: We identified 333 667 persons without prevalent cancer and not receiving Cbl treatment. Six percent had Cbl levels greater than the upper reference limit (≥601 pmol/L). Cancer risk......BACKGROUND: A substantial proportion of patients referred for plasma vitamin B12 (cobalamin [Cbl]) measurement present with high Cbl levels, which have been reported in patients with different cancer types. However, the cancer risk among patients with newly diagnosed high Cbl levels has not been...... adequately examined. METHODS: We conducted this cohort study using population-based Danish medical registries. Patients referred for Cbl measurement with levels greater than the lower reference limit (≥200 pmol/L) were identified from the population of Northern Denmark during the period of 1998 to 2009 using...

  18. Structural and magnetic characterization of Co67Fe4Ni2Si15B12

    International Nuclear Information System (INIS)

    Manjura Hoque, S.; Khan, F.A.; Hakim, M.A.

    2007-01-01

    Soft magnetic properties of Co-based amorphous alloy of the composition Co 67 Fe 4 Ni 2 Si 15 B 12 have been investigated by isothermal heat treatment up to the conventional crystallization temperature. In the as-cast condition the Curie temperature of the sample is 272 deg. C and saturation magnetization is 74 emu/g. Magnetic properties undergo variation depending on the heat treatment temperature. For the heat treatment temperatures of around 420 and 490 deg. C, superior soft magnetic properties are obtained. For both the temperatures initial permeability, μ' reaches value up to ten times the value of permeability in the as-received samples. Annealing effect on giant magneto-impedance has been observed for the current-driving frequencies of 4.5 and 6 MHz. Field dependence of magneto-impedance shows hysteresis at low field, which is related to the changes in the magnetization process of the sample

  19. Prototype explosives detection system based on nuclear resonance absorption in nitrogen

    International Nuclear Information System (INIS)

    Morgado, R.E.; Arnone, G.J.; Cappiello, C.C.

    1996-01-01

    A laboratory prototype system has been developed for the experimental evaluation of an explosives detection technique based on nuclear resonance absorption of gamma rays in nitrogen. Major subsystems include a radiofrequency quadrupole proton accelerator and associated beam transport system, a high-power gamma-ray production target, an airline-luggage tomographic inspection system, and an image- processing/detection-alarm subsystem. The detection system performance, based on a limited experimental test, is reported

  20. Smoking Discriminately Changes the Serum Active and Non-Active Forms of Vitamin B12.

    Science.gov (United States)

    Shekoohi, Niloofar; Javanbakht, Mohammad Hassan; Sohrabi, Marjan; Zarei, Mahnaz; Mohammadi, Hamed; Djalali, Mahmoud

    2017-06-01

    Smoking may modify the appetite, and consequently affect nutrient intake and serum micronutrients. The effect of smoking on vitamin B12 status has been considered in several studies. The research proposed that organic nitrites, nitro oxide, cyanides, and isocyanides of cigarette smoke interfere with vitamin B12 metabolism, and convert it to inactive forms. This research was carried out to determine the serum level of active and inactive forms of vitamin B12 in male smokers in comparison with male nonsmokers. This is a case-control study, in which the participants were 85 male smokers and 85 male nonsmokers. The serum levels of total and active form of vitamin B12 were measured. Dietary intake was recorded by a quantitative food frequency questionnaire and one-day 24-hour dietary recall method. Independent two sample T test was used to compare quantitative variables between the case and control groups. The serum level of total vitamin B12 was not significantly different between two groups, but serum level of active form of vitamin B12 in the smoking group was significantly lower than non-smoking group (Psmokers in the Iranian community. The results of this study identified that serum level of total vitamin B12 might be not different between smoking and non-smoking people, but the function of this vitamin is disturbed in the body of smokers through the reduction of serum level of active form of vitamin B12.

  1. Inhibition of the vitamin B12 binding capacity of proteins by the hydrolysis product of cyclophosphamide

    International Nuclear Information System (INIS)

    Fenrych, W.; Ignatowicz, E.; Szczodrowska, E.

    1993-01-01

    The inhibitory effect of cyclophosphamide hydrolysis product (CPHP) on vitamin B 12 binding ability to proteins has been established. The ester N-(2-chloroethyl)-N'-(3-phosphopropyl)-etheylenediamine hydrochloride is probably responsible, in vitro, for blocking the protein binding sites. Preincubation of proteins with vitamin B 12 prevents the inhibitory effect of CPHP. (au)

  2. The complete coenzyme B12 biosynthesis gene cluster of Lactobacillus reuteri CRL 1098

    NARCIS (Netherlands)

    Santos, dos F.; Vera, J.L.; Heijden, van der R.; Valdez, G.F.; Vos, de W.M.; Sesma, F.; Hugenholtz, J.

    2008-01-01

    The coenzyme B12 production pathway in Lactobacillus reuteri has been deduced using a combination of genetic, biochemical and bioinformatics approaches. The coenzyme B12 gene cluster of Lb. reuteri CRL1098 has the unique feature of clustering together the cbi, cob and hem genes. It consists of 29

  3. Vitamin B12 status and its association with Helicobacter pylori infection in alcohol dependent patients

    NARCIS (Netherlands)

    van Oijen, Martijn G. H.; Laheij, Robert J. F.; de Jong, Cor A. J.; Peters, Wilbert H. M.; Jansen, Jan B. M. J.

    2004-01-01

    Both infection with Helicobacter pylori and alcohol abuse have been associated with low vitamin B12 serum levels. The interaction between both risk factors is unknown. The aim of this study was to determine whether Helicobacter pylori infection is associated with low vitamin B12 levels in alcohol

  4. Low vitamin B-12 status and risk of cognitive decline in older adults

    DEFF Research Database (Denmark)

    Clarke, Robert; Birks, Jacqueline; Nexo, Ebba

    2007-01-01

    BACKGROUND: Elevated total homocysteine (tHcy) concentrations have been associated with cognitive impairment, but it is unclear whether low vitamin B-12 or folate status is responsible for cognitive decline. OBJECTIVE: We examined the associations of cognitive decline with vitamin B-12 and folate...

  5. Vitamin B12 deficiency presenting as an acute confusional state: A ...

    African Journals Online (AJOL)

    Results: We report a case of a 44 year old female patient referred to the haematology unit with vitamin B12 deficiency presenting as an acute confusional state or delirium. Total resolution of the psychiatric symptoms occurred following parenteral vitamin B12 replacement therapy. Conclusion: This case report highlights one ...

  6. Loss of vitamin B(12) in fish (round herring) meats during various cooking treatments.

    Science.gov (United States)

    Nishioka, Michiko; Kanosue, Fuki; Yabuta, Yukinori; Watanabe, Fumio

    2011-01-01

    The loss of vitamin B(12) in round herring meats during various cooking treatments was evaluated. Although amounts of vitamin B(12) were three times greater in the viscera (37.5 ± 10.6 µg/100 g fresh weight) than in the meats, about 73% of total vitamin B(12) found in the whole fish body (except for head and bones) were recovered in the meats (5.1 ± 1.0 µg of vitamin B(12)). The vitamin B(12) contents of the round herring's meats were significantly decreased up to ~62% during cooking by grilling, boiling, frying, steaming, and microwaving. There was, however, no loss of vitamin B(12) during vacuum-packed pouch cooking. Model experiment using hydroxocobalamin suggest that loss of vitamin B(12) is dependent on the degree of temperature and time used in conventional cooking, and is further affected by the concomitant ingredients of food. Retention of vitamin B(12) was not dependent on vacuum or temperature (or both) used in the vacuum-packed pouch cooking.

  7. Genetic determinants of serum vitamin B12 and their relation to body mass index

    DEFF Research Database (Denmark)

    Allin, Kristine H.; Friedrich, Nele; Pietzner, Maik

    2017-01-01

    (-4)). We found no support for a causal role of decreased serum vitamin B12 levels in obesity. However, our study suggests that FUT2, through its regulation of the cross-talk between gut microbes and the human host, might explain a part of the observational association between serum vitamin B12 and BMI....

  8. Vitamin B 12 levels in patients with type 2 diabetes mellitus on ...

    African Journals Online (AJOL)

    Methods: Serum vitamin B12 level was determined using high performance liquid chromatography (HPLC) in 81 T2DM patients who have been on metformin for 5 years or more. Vitamin B12 deficiency was defined as serum concentration of 300 pg/dl as normal.

  9. Diffuse reflectance relations based on diffusion dipole theory for large absorption and reduced scattering.

    Science.gov (United States)

    Bremmer, Rolf H; van Gemert, Martin J C; Faber, Dirk J; van Leeuwen, Ton G; Aalders, Maurice C G

    2013-08-01

    Diffuse reflectance spectra are used to determine the optical properties of biological samples. In medicine and forensic science, the turbid objects under study often possess large absorption and/or scattering properties. However, data analysis is frequently based on the diffusion approximation to the radiative transfer equation, implying that it is limited to tissues where the reduced scattering coefficient dominates over the absorption coefficient. Nevertheless, up to absorption coefficients of 20  mm-1 at reduced scattering coefficients of 1 and 11.5  mm-1, we observed excellent agreement (r2=0.994) between reflectance measurements of phantoms and the diffuse reflectance equation proposed by Zonios et al. [Appl. Opt.38, 6628-6637 (1999)], derived as an approximation to one of the diffusion dipole equations of Farrell et al. [Med. Phys.19, 879-888 (1992)]. However, two parameters were fitted to all phantom experiments, including strongly absorbing samples, implying that the reflectance equation differs from diffusion theory. Yet, the exact diffusion dipole approximation at high reduced scattering and absorption also showed agreement with the phantom measurements. The mathematical structure of the diffuse reflectance relation used, derived by Zonios et al. [Appl. Opt.38, 6628-6637 (1999)], explains this observation. In conclusion, diffuse reflectance relations derived as an approximation to the diffusion dipole theory of Farrell et al. can analyze reflectance ratios accurately, even for much larger absorption than reduced scattering coefficients. This allows calibration of fiber-probe set-ups so that the object's diffuse reflectance can be related to its absorption even when large. These findings will greatly expand the application of diffuse reflection spectroscopy. In medicine, it may allow the use of blue/green wavelengths and measurements on whole blood, and in forensic science, it may allow inclusion of objects such as blood stains and cloth at crime

  10. Water-based metamaterial absorbers for optical transparency and broadband microwave absorption

    Science.gov (United States)

    Pang, Yongqiang; Shen, Yang; Li, Yongfeng; Wang, Jiafu; Xu, Zhuo; Qu, Shaobo

    2018-04-01

    Naturally occurring water is a promising candidate for achieving broadband absorption. In this work, by virtue of the optically transparent character of the water, the water-based metamaterial absorbers (MAs) are proposed to achieve the broadband absorption at microwave frequencies and optical transparence simultaneously. For this purpose, the transparent indium tin oxide (ITO) and polymethyl methacrylate (PMMA) are chosen as the constitutive materials. The water is encapsulated between the ITO backed plate and PMMA, serving as the microwave loss as well as optically transparent material. Numerical simulations show that the broadband absorption with the efficiency over 90% in the frequency band of 6.4-30 GHz and highly optical transparency of about 85% in the visible region can be achieved and have been well demonstrated experimentally. Additionally, the proposed water-based MA displays a wide-angle absorption performance for both TE and TM waves and is also robust to the variations of the structure parameters, which is much desired in a practical application.

  11. Transition between laser absorption dominated regimes in carbon-based plasma

    Directory of Open Access Journals (Sweden)

    K. Hajisharifi

    2017-09-01

    Full Text Available In this work, we investigate the energy absorption enhancement of a laser by adding a variety of light ion species to a primarily carbon-based plasma during the high-power laser interaction with the finite size targets. A developed Particle-In-Cell simulation code is used to study the reduction of laser reflectivity (stimulated backward scatterings in both Brillouin- and Raman-dominated regimes. The simulation is performed in various Carbon-light ion plasmas such as Carbon-Hydrogen, Carbon-Helium, Carbon-Deuterium, and Carbon-Tritium. The results show that, in the optimized condition, the inclusion of light Hydrogen ions into the Carbon-based plasma up to 50%-50% mixture enhances the laser absorption exceeding 20% in the Brillouin regime due to the suppression of laser reflectivity in contract to 4% in the Raman-dominated regime. Moreover, the absorption dominated regime switches from Raman to Brillouin regime by adding 50% of Hydrogen ions to a purely carbon target. The results of this investigation will be applicable to the laser-plasma experiments so long as the laser energy absorption in the Carbon plasma target, the most readily available material in laboratory, is concerned.

  12. Reposição de vitamina B12 reduz comportamento depressivo induzido em ratos jovens = Vitamin B12 replacement therapy reduces induced depressive behavior in young rats

    Directory of Open Access Journals (Sweden)

    Brito, Adriana Maria de Oliveira

    2016-01-01

    Conclusões: A depleção suave de vitamina B12 na dieta, em nível não indutor de anemia, favoreceu o estado depressivo em ratos jovens, enquanto a sua suplementação na situação de depleção reverteu esse quadro. Em condições de nutrição adequada, entretanto, a suplementação dessa vitamina não exerceu efeito sobre o estado depressivo. Estes resultados estimulam a realização de mais estudos que aprofundem a avaliação das relações entre vitamina B12 e depressão em jovens. Além disso, este estudo também abre perspectivas para um novo modelo experimental de depressão, induzida por depleção de vitamina B12

  13. Low vitamin B-12 status and risk of cognitive decline in older adults

    DEFF Research Database (Denmark)

    Clarke, Robert; Birks, Jacqueline; Nexo, Ebba

    2007-01-01

    remained significant. CONCLUSIONS: Low vitamin B-12 status was associated with more rapid cognitive decline. Randomized trials are required to determine the relevance of vitamin B-12 supplementation for prevention of dementia. Udgivelsesdato: 2007-Nov......BACKGROUND: Elevated total homocysteine (tHcy) concentrations have been associated with cognitive impairment, but it is unclear whether low vitamin B-12 or folate status is responsible for cognitive decline. OBJECTIVE: We examined the associations of cognitive decline with vitamin B-12 and folate...... status in a longitudinal cohort study performed from 1993 to 2003 in Oxford, United Kingdom. DESIGN: Cognitive function was assessed with the Mini-Mental State Examination on >/=3 occasions during 10 y and related to serum concentrations of vitamin B-12, holotranscobalamin (holoTC), tHcy, methylmalonic...

  14. Determination of absorption cross-section of Si nanocrystals by two independent methods based on either absorption or luminescence

    Czech Academy of Sciences Publication Activity Database

    Valenta, J.; Greben, M.; Remeš, Zdeněk; Gutsch, S.; Hiller, D.; Zacharias, M.

    2016-01-01

    Roč. 102, č. 2 (2016), 1-5, č. článku 023102. ISSN 0003-6951 R&D Projects: GA ČR(CZ) GA14-05053S; GA MŠk(CZ) LD14011 Institutional support: RVO:68378271 Keywords : photoluminescence * absorption spectroscopy * photothermal spectroscopy * semiconductors * nanocrystals Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.411, year: 2016

  15. B12 deficiency increases with age in hospitalized patients: a study on 14,904 samples.

    Science.gov (United States)

    Mézière, Anthony; Audureau, Etienne; Vairelles, Stéphane; Krypciak, Sébastien; Dicko, Michèle; Monié, Marguerite; Giraudier, Stéphane

    2014-12-01

    Cobalamin deficiency is responsible for hematological, neurological, neurocognitive, and neuropsychiatric impairments and is a risk factor for cardiovascular diseases, particularly in the elderly people. In order to determine B12 status in old inpatients, a total number of 14,904 hospitalized patients in whom B12 measurements were performed in five hospitals in the Paris metropolitan area were included from January 1, 2011 to December 31, 2011. The aims of the study were to determine whether age had an impact on B12 and folate deficiencies and to evaluate correlations between B12 and biological parameters-folate, hemoglobin, mean cell volume, homocystein (tHcy)-and age. Patients were aged 70.3±19.5 years. Low B12 concentration ( 17 µmol/L), 20.4% had low folate concentration (folate 17 µmol/L), and 4.7% of patients were both functional B12 and folate deficient. The B12 or folate deficient patients had lower mean cell volume level than nondeficient patients. Increase in mean cell volume and tHcy concentrations with age and decrease in B12, folate, and hemoglobin levels with age were observed. Frequency of functional B12 deficiency was 9.6% in patients aged 30-60 years and 14.2% in patients over 90 years. Frequency of functional folate deficiency was 9.5% in 30-60 years and 12.1% in >90 years. In inpatients, functional B12 deficiency and functional folate deficiency increase with age and are not associated with anemia or macrocytosis. False vitamin B deficiencies are frequent. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Vitamin B12 supplement alleviates N'-nitrosodimethylamine-induced hepatic fibrosis in rats.

    Science.gov (United States)

    Ahmad, Areeba; Afroz, Nishat; Gupta, Umesh D; Ahmad, Riaz

    2014-01-10

    Abstract Context: Altered vitamin B 12 levels have been correlated with hepatotoxicity; however, further evidence is required to establish its protective role. Objective: To evaluate the effects of vitamin B 12 supplement in protecting N'-nitrosodimethylamine (NDMA)-induced hepatic fibrosis in Wistar rats. Materials and methods: Hepatic fibrosis was induced by administering NDMA in doses of 10 mg/kg body weight thrice a week for 21 days. Another group received equal doses (10 mg/kg body weight) of vitamin B 12 subsequent to NDMA treatment. Animals from either group were sacrificed weekly from the start of the treatment along with their respective controls. Progression of hepatic fibrosis, in addition to the effect of vitamin B 12 , was assessed biochemically for liver function biomarkers, liver glycogen, hydroxyproline (HP) and B 12 reserves along with histopathologically by hematoxylin and eosin (H & E) as well immunohistochemical staining for α-SMA expression. Results and discussion: Elevation in the levels of aminotransferases, SALP, total bilirubin and HP was observed in NDMA treated rats, which was concomitant with remarkable depletion in liver glycogen and B 12 reserves (p < 0.05). Liver biopsies also demonstrated disrupted lobular architecture, collagen amassing and intense fibrosis by NDMA treatment. Immunohistochemical staining showed the presence of activated stellate cells that was dramatically increased up to day 21 in fibrotic rats. Following vitamin B 12 treatment, liver function biomarkers, glycogen contents and hepatic vitamin B 12 reserves were restored in fibrotic rats, significantly. Vitamin B 12 administration also facilitated restoration of normal liver architecture. Conclusion: These findings provide interesting new evidence in favor of protective role for vitamin B 12 against NDMA-induced hepatic fibrosis in rats.

  17. Hybrid Microfluidic Platform for Multifactorial Analysis Based on Electrical Impedance, Refractometry, Optical Absorption and Fluorescence

    Directory of Open Access Journals (Sweden)

    Fábio M. Pereira

    2016-10-01

    Full Text Available This paper describes the development of a novel microfluidic platform for multifactorial analysis integrating four label-free detection methods: electrical impedance, refractometry, optical absorption and fluorescence. We present the rationale for the design and the details of the microfabrication of this multifactorial hybrid microfluidic chip. The structure of the platform consists of a three-dimensionally patterned polydimethylsiloxane top part attached to a bottom SU-8 epoxy-based negative photoresist part, where microelectrodes and optical fibers are incorporated to enable impedance and optical analysis. As a proof of concept, the chip functions have been tested and explored, enabling a diversity of applications: (i impedance-based identification of the size of micro beads, as well as counting and distinguishing of erythrocytes by their volume or membrane properties; (ii simultaneous determination of the refractive index and optical absorption properties of solutions; and (iii fluorescence-based bead counting.

  18. Tailored Algorithm for Sensitivity Enhancement of Gas Concentration Sensors Based on Tunable Laser Absorption Spectroscopy.

    Science.gov (United States)

    Vargas-Rodriguez, Everardo; Guzman-Chavez, Ana Dinora; Baeza-Serrato, Roberto

    2018-06-04

    In this work, a novel tailored algorithm to enhance the overall sensitivity of gas concentration sensors based on the Direct Absorption Tunable Laser Absorption Spectroscopy (DA-ATLAS) method is presented. By using this algorithm, the sensor sensitivity can be custom-designed to be quasi constant over a much larger dynamic range compared with that obtained by typical methods based on a single statistics feature of the sensor signal output (peak amplitude, area under the curve, mean or RMS). Additionally, it is shown that with our algorithm, an optimal function can be tailored to get a quasi linear relationship between the concentration and some specific statistics features over a wider dynamic range. In order to test the viability of our algorithm, a basic C 2 H 2 sensor based on DA-ATLAS was implemented, and its experimental measurements support the simulated results provided by our algorithm.

  19. Optical Absorption and Electron Injection of 4-(Cyanomethylbenzoic Acid Based Dyes: A DFT Study

    Directory of Open Access Journals (Sweden)

    Yuehua Zhang

    2015-01-01

    Full Text Available Density functional theory (DFT and time-dependent density functional theory (TDDFT calculations were carried out to study the ground state geometries, electronic structures, and absorption spectra of 4-(cyanomethylbenzoic acid based dyes (AG1 and AG2 used for dye-sensitized solar cells (DSSCs. The excited states properties and the thermodynamical parameters of electron injection were studied. The results showed that (a two dyes have uncoplanar structures along the donor unit and conjugated bridge space, (b two sensitizers exhibited intense absorption in the UV-Vis region, and (c the excited state oxidation potential was higher than the conduction band edge of TiO2 photoanode. As a result, a solar cell based on the 4-(cyanomethylbenzoic acid based dyes exhibited well photovoltaic performance. Furthermore, nine dyes were designed on the basis of AG1 and AG2 to improve optical response and electron injection.

  20. Identification of ABC transporters acting in vitamin B12 metabolism in Caenorhabditis elegans.

    Science.gov (United States)

    McDonald, Megan K; Fritz, Julie-Anne; Jia, Dongxin; Scheuchner, Deborah; Snyder, Floyd F; Stanislaus, Avalyn; Curle, Jared; Li, Liang; Stabler, Sally P; Allen, Robert H; Mains, Paul E; Gravel, Roy A

    2017-12-01

    Vitamin B 12 (cobalamin, Cbl) is a micronutrient essential to human health. Cbl is not utilized as is but must go through complex subcellular and metabolic processing to generate two cofactor forms: methyl-Cbl for methionine synthase, a cytosolic enzyme; and adenosyl-Cbl for methylmalonyl-CoA mutase, a mitochondrial enzyme. Some 10-12 human genes have been identified responsible for the intracellular conversion of Cbl to cofactor forms, including genes that code for ATP-binding cassette (ABC) transporters acting at the lysosomal and plasma membranes. However, the gene for mitochondrial uptake is not known. We hypothesized that ABC transporters should be candidates for other uptake and efflux functions, including mitochondrial transport, and set out to screen ABC transporter mutants for blocks in Cbl utilization using the nematode roundworm Caenorhabditis elegans. Thirty-seven mutant ABC transporters were screened for the excretion of methylmalonic acid (MMA), which should result from loss of Cbl transport into the mitochondria. One mutant, wht-6, showed elevated MMA excretion and reduced [ 14 C]-propionate incorporation, pointing to a functional block in methylmalonyl-CoA mutase. In contrast, the wht-6 mutant appeared to have a normal cytosolic pathway based on analysis of cystathionine excretion, suggesting that cytosolic methionine synthase was functioning properly. Further, the MMA excretion in wht-6 could be partially reversed by including vitamin B 12 in the assay medium. The human ortholog of wht-6 is a member of the G family of ABC transporters. We propose wht-6 as a candidate for the transport of Cbl into mitochondria and suggest that a member of the corresponding ABCG family of ABC transporters has this role in humans. Our ABC transporter screen also revealed that mrp-1 and mrp-2 mutants excreted lower MMA than wild type, suggesting they were concentrating intracellular Cbl, consistent with the cellular efflux defect proposed for the mammalian MRP1 ABC

  1. Ultrasonographic evaluation to diagnose hepatic lipidosis in Egyptian Zaraibi goats with vitamin B12 deficiency

    Directory of Open Access Journals (Sweden)

    Sabry A. El-Khodery

    2011-01-01

    Full Text Available As little is known about the ultrasonographic features of hepatic lipidosis (white liver disease in goats, this study was undertaken to evaluate the use of ultrasound for the diagnosis of hepatic lipidosis associated with vitamin B12 (cyanocobalamin deficiency in Egyptian Zaraibi goats. A total of 38 goats (28 with weight loss, diarrhoea and anaemia and 10 clinically healthy were studied. Twenty-one goats were demonstrated to have cobalt and cyanocobalamin deficiency (0.33 ± 0.12 μmol/l and 0.17 ± 0.10 μg/l, respectively. Goats were examined with a real-time ultrasound system using a 5-MHz convex transducer. Ultrasound-guided liver biopsies and blood samples were obtained from each animal at examination. Based on the histopathological findings, diseased goats were classified as having mild (n = 6, moderate (n = 6 or severe lipidosis (n = 9. Ultrasonographic-hepatic changes were recorded in 19 (90.4% out of 21 goats. Severe lipidosis showed diffuse hyper-echogenicity of hepatic parenchyma. However, focal hyper-echoic lesions with various shapes, sizes and positions were visualized in mild and moderate lipidosis. Liver size increased significantly (P < 0.05 in severely affected goats compared with the controls. Histopathologically, macrovacuolations, congestion of hepatic sinusoids and infiltration of the portal area with inflammatory cells and connective tissues were evident in moderate and severely affected cases. There were varying degrees of anaemia, hypoglycemia and hypoproteinemia with significant increases (P < 0.05 of aspartate aminotransferase (AST and alkaline phosphatase (ALP in diseased animals compared with the controls. In conclusion, ultrasound may be a useful diagnostic tool in goats with suspected hepatic lipidosis associated with vitamin B12 deficiency.

  2. Correlation between serum vitamin B12 level and peripheral neuropathy in atrophic gastritis

    Science.gov (United States)

    Yang, Guo-Tao; Zhao, Hong-Ying; Kong, Yu; Sun, Ning-Ning; Dong, Ai-Qin

    2018-01-01

    AIM To explore the correlation between serum vitamin B12 level and peripheral neuropathy in patients with chronic atrophic gastritis (CAG). METHODS A total of 593 patients diagnosed with chronic gastritis by gastroscopy and pathological examination from September 2013 to September 2016 were selected for this study. The age of these patients ranged within 18- to 75-years-old. Blood pressure, height and weight were measured in each patient, and the body mass index value was calculated. Furthermore, gastric acid, serum gastrin, serum vitamin and serum creatinine tests were performed, and peripheral nerve conduction velocity and Helicobacter pylori (H. pylori) were detected. In addition, the type of gastritis was determined by gastroscopy. The above factors were used as independent variables to analyze chronic gastritis with peripheral neuropathy and vitamin B12 deficiency risk factors, and to analyze the relationship between vitamin B12 levels and peripheral nerve conduction velocity. In addition, in the treatment of CAG on the basis of vitamin B12, patients with peripheral neuropathy were observed. RESULTS Age, H. pylori infection, CAG, vitamin B9 and vitamin B12 were risk factors for the occurrence of peripheral nerve degeneration. Furthermore, CAG and H. pylori infection were risk factors for chronic gastritis associated with vitamin B12 deficiency. Serum vitamin B12 level was positively correlated with sensory nerve conduction velocity in the tibial nerve (R = 0.463). After vitamin B12 supplementation, patients with peripheral neuropathy improved. CONCLUSION Serum vitamin B12 levels in patients with chronic gastritis significantly decreased, and the occurrence of peripheral neuropathy had a certain correlation. CAG and H. pylori infection are risk factors for vitamin B12 deficiency and peripheral neuropathy. When treating CAG, vitamin B12 supplementation can significantly reduce peripheral nervous system lesions. Therefore, the occurrence of peripheral neuropathy

  3. Investigation of clinical pharmacokinetic variability of an opioid antagonist through physiologically based absorption modeling.

    Science.gov (United States)

    Ding, Xuan; He, Minxia; Kulkarni, Rajesh; Patel, Nita; Zhang, Xiaoyu

    2013-08-01

    Identifying the source of inter- and/or intrasubject variability in pharmacokinetics (PK) provides fundamental information in understanding the pharmacokinetics-pharmacodynamics relationship of a drug and project its efficacy and safety in clinical populations. This identification process can be challenging given that a large number of potential causes could lead to PK variability. Here we present an integrated approach of physiologically based absorption modeling to investigate the root cause of unexpectedly high PK variability of a Phase I clinical trial drug. LY2196044 exhibited high intersubject variability in the absorption phase of plasma concentration-time profiles in humans. This could not be explained by in vitro measurements of drug properties and excellent bioavailability with low variability observed in preclinical species. GastroPlus™ modeling suggested that the compound's optimal solubility and permeability characteristics would enable rapid and complete absorption in preclinical species and in humans. However, simulations of human plasma concentration-time profiles indicated that despite sufficient solubility and rapid dissolution of LY2196044 in humans, permeability and/or transit in the gastrointestinal (GI) tract may have been negatively affected. It was concluded that clinical PK variability was potentially due to the drug's antagonism on opioid receptors that affected its transit and absorption in the GI tract. Copyright © 2013 Wiley Periodicals, Inc.

  4. A radioisotope dilution assay for unlabelled vitamin B12-intrinsic factor complex employing the binding intrinsic factor antibody: probable evidence for two types of binding antibody

    International Nuclear Information System (INIS)

    Jacob, E.; O'Brien, H.A.W.; Mollin, D.L.

    1977-01-01

    A new radioisotope dilution assay for vitamin B 12 -intrinsic factor complex is described. The method is based on the use of the binding type intrinsic antibody (the binding reagent), which when combined with the intrinsic factor-vitamin B 12 complex (labelled ligand), is quantitatively adsorbed onto zirconium phosphate gel pH 6.25. The new assay has been shown to provide a measure of intrinsic factor comparable with other intrinsic factor assays, but it has the important advantage of being able to measure the unlabelled vitamin B 12 -intrinsic factor complex (unlabelled ligand), and will, therefore, be valuable in the study of physiological events in the gastrointestinal tract. During the study, it was found that there is some evidence for at least two types of binding intrinsic factor antibody: One which combines preferentially with the intrinsic factor-vitamin B 12 complex and one which combines equally well with this complex or with free intrinsic factor. (author)

  5. Vitamin B-12 treatment of asymptomatic, deficient, elderly Chileans improves conductivity in myelinated periphreal nerves, but high serum folate impairs vitamin B-12 status response assessed by the combined indicator of..

    Science.gov (United States)

    Since 2005 the National Feeding Program for the Elderly (PACAM) in Chile has provided a B12 fortified milk drink (1.7 µg B12/d) which is insufficient to ensure B12 adequacy in many individuals. The objective was to evaluate effects of adding 1 mg B12/d to PACAM vs 1 mg B12/d as a pill with PACAM on ...

  6. Space Launch System Base Heating Test: Tunable Diode Laser Absorption Spectroscopy

    Science.gov (United States)

    Parker, Ron; Carr, Zak; MacLean, Mathew; Dufrene, Aaron; Mehta, Manish

    2016-01-01

    This paper describes the Tunable Diode Laser Absorption Spectroscopy (TDLAS) measurement of several water transitions that were interrogated during a hot-fire testing of the Space Launch Systems (SLS) sub-scale vehicle installed in LENS II. The temperature of the recirculating gas flow over the base plate was found to increase with altitude and is consistent with CFD results. It was also observed that the gas above the base plate has significant velocity along the optical path of the sensor at the higher altitudes. The line-by-line analysis of the H2O absorption features must include the effects of the Doppler shift phenomena particularly at high altitude. The TDLAS experimental measurements and the analysis procedure which incorporates the velocity dependent flow will be described.

  7. Is vitamin B12 deficiency a risk factor for cardiovascular disease in vegetarians?

    Science.gov (United States)

    Pawlak, Roman

    2015-06-01

    The goal of this paper is to describe the role of vitamin B12 deficiency in cardiovascular disease development among vegetarians. Vegetarians have a high prevalence of vitamin B12 deficiency. Deficiency of this vitamin is associated with a variety of atherogenic processes that are mainly, but not exclusively, due to vitamin B12 deficiency-induced hyperhomocysteinemia. Each 5-μmol/L increase above 10 μmol/L of serum homocysteine is associated with a 20% increased risk of circulatory health problems. Mean homocysteine concentration >10 μmol/L among vegetarians was reported in 32 of 34 reports. Macrocytosis associated with vitamin B12 deficiency is also associated with fatal and non-fatal coronary disease, myocardial infarction, stroke, and other circulatory health problems. Compared with non-vegetarians, vegetarians have an improved profile of the traditional cardiovascular disease risk factors, including serum lipids, blood pressure, serum glucose concentration, and weight status. However, not all studies that assessed cardiovascular disease incidence among vegetarians reported a protective effect. Among studies that did show a lower prevalence of circulatory health problems, the effect was not as pronounced as expected, which may be a result of poor vitamin B12 status due to a vegetarian diet. Vitamin B12 deficiency may negate the cardiovascular disease prevention benefits of vegetarian diets. In order to further reduce the risk of cardiovascular disease, vegetarians should be advised to use vitamin B12 supplements. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  8. Mathematical modeling of glutathione status in type 2 diabetics with vitamin B12 deficiency

    Directory of Open Access Journals (Sweden)

    Varun eKaramshetty

    2016-03-01

    Full Text Available Deficiencies in vitamin B12 and glutathione (GSH are associated with anumber of diseases including type 2 diabetes mellitus. We tested newly diag-nosed Indian diabetic patients for correlation between their vitamin B12 andGSH, and found it to be weak. Here we seek to examine the theoreticaldependence of GSH on vitamin B12 with a mathematical model of 1-carbonmetabolism due to Reed and co-workers. We study the methionine cycleof the Reed-Nijhout model by developing a simple ‘stylized model’ that cap-tures its essential topology and whose kinetics are analytically tractable. Theanalysis shows – somewhat counter-intuitively – that the flux responsible forthe homeostasis of homocysteine is, in fact, peripheral to the methioninecycle. Elevation of homocysteine arises from reduced activity of methioninesynthase, a vitamin B12-dependent enzyme, however, this does not increaseGSH biosynthesis. The model suggests that the lack of vitamin B12–GSHcorrelation is explained by suppression of activity in the trans-sulfurationpathway that limits the synthesis of cysteine and GSH from homocysteine.We hypothesize this ‘cysteine-block’ is an essential consequence of vitaminB12 deficiency. It can be clinically relevant to appreciate that these secondaryeffects of vitamin B12 deficiency could be central to its pathophysiology.

  9. Measurement of FA and VitB12 in serum by TRFIA and its clinical application

    International Nuclear Information System (INIS)

    Zhou Jinhong; Wang Huimin

    2006-01-01

    To investigate the correlation between diseases and the quantity of folic acid(FA) and vitamine B 12 (VitB 12 ) in serum, the quantity of FA and VitB 12 in serum was measured by TR- FIA. The results showed that the levels of FA and VitB 12 in 68 controlled subjects were 20.13±5.72 nmol/L and 240.45±58.23 pmol/L respectively. The levels of FA and VitB 12 in 6 patients with megaloblastic anemia, 26 with medium-terminal gestation femineity, 7 with liver cirrhosis, 10 with gastric ulcerand 31 with cerebral infarction were significant lower than those in the control group. The level of FA in 24 with malignant hematopathy and 57 with malignant tumor was significantly lower but VitB 12 between the 31 patients with iron deficiency anemia and 12 with CAA and the control group. The amount of the FA in 9 patients with chronic atrophic gastritis and 42 blood donors were lower than that in the control. The determination of FA and VitB 12 levels may be quite significant in the diagnosis, therapy and prognosis of diseases. Laboratories should establish the reference values which fit the locals specifically. (authors)

  10. High vitamin B12 level and good treatment outcome may be associated in major depressive disorder

    Directory of Open Access Journals (Sweden)

    Tanskanen Antti

    2003-12-01

    Full Text Available Abstract Background Despite of an increasing body of research the associations between vitamin B12 and folate levels and the treatment outcome in depressive disorders are still unsolved. We therefore conducted this naturalistic prospective follow-up study. Our aim was to determine whether there were any associations between the vitamin B12 and folate level and the six-month treatment outcome in patients with major depressive disorder. Because vitamin B12 and folate deficiency may result in changes in haematological indices, including mean corpuscular volume, red blood cell count and hematocrit, we also examined whether these indices were associated with the treatment outcome. Methods Haematological indices, erythrocyte folate and serum vitamin B12 levels were determined in 115 outpatients with DSM-III-R major depressive disorder at baseline and serum vitamin B12 level again on six-month follow-up. The 17-item Hamilton Depression Rating Scale was also compiled, respectively. In the statistical analysis we used chi-squared test, Pearson's correlation coefficient, the Student's t-test, analysis of variance (ANOVA, and univariate and multivariate linear regression analysis. Results Higher vitamin B12 levels significantly associated with a better outcome. The association between the folate level and treatment outcome was weak and probably not independent. No relationship was found between haematological indices and the six-month outcome. Conclusion The vitamin B12 level and the probability of recovery from major depression may be positively associated. Nevertheless, further studies are suggested to confirm this finding.

  11. Combined vitamin B-12 and balanced protein-energy supplementation affect homocysteine remethylation in the methionine cycle in pregnant south Indian women of low vitamin B-12 status

    Science.gov (United States)

    Low-quality dietary protein intake and vitamin B-12 deficiency could interact to decrease methionine transmethylation and remethylation rates during pregnancy, and may affect epigenetic modifications of the fetal genome. The objective of this randomized, partially open-labeled intervention trial was...

  12. Bread cofortified with folic acid and vitamin B-12 improves the folate and vitamin B-12 status of healthy older people: a randomized controlled trial

    NARCIS (Netherlands)

    Winkels, R.M.; Brouwer, I.A.; Clarke, R.; Katan, M.B.; Verhoef, P.

    2008-01-01

    Background: Mandatory fortification of flour with folic acid has reduced the number of neural tube defects in North America. Concerns that high intakes of folic acid might mask vitamin B-12 deficiency in older persons have delayed the introduction of fortification in many European countries.

  13. Vitamin B(12) dependent changes in mouse spinal cord expression of vitamin B(12) related proteins and the epidermal growth factor system

    DEFF Research Database (Denmark)

    Mutti, Elena; Lildballe, Dorte L; Kristensen, Lise

    2013-01-01

    Chronic vitamin B(12) (cobalamin) deficiency in the mammalian central nervous system causes degenerative damage, especially in the spinal cord. Previous studies have shown that cobalamin status alters spinal cord expression of epidermal growth factor (EGF) and its receptor in rats. Employing...

  14. Smoking Discriminately Changes the Serum Active and Non-Active Forms of Vitamin B12

    Directory of Open Access Journals (Sweden)

    Niloofar Shekoohi

    2017-08-01

    Full Text Available Smoking may modify the appetite, and consequently affect nutrient intake and serum micronutrients. The effect of smoking on vitamin B12 status has been considered in several studies. The research proposed that organic nitrites, nitro oxide, cyanides, and isocyanides of cigarette smoke interfere with vitamin B12 metabolism, and convert it to inactive forms. This research was carried out to determine the serum level of active and inactive forms of vitamin B12 in male smokers in comparison with male nonsmokers. This is a case-control study, in which the participants were 85 male smokers and 85 male nonsmokers. The serum levels of total and active form of vitamin B12 were measured. Dietary intake was recorded by a quantitative food frequency questionnaire and one-day 24-hour dietary recall method. Independent two sample T test was used to compare quantitative variables between the case and control groups. The serum level of total vitamin B12 was not significantly different between two groups, but serum level of active form of vitamin B12 in the smoking group was significantly lower than non-smoking group (P<0.001. This is one of the first studies that evaluated the serum level of active form of vitamin B12 in smokers in the Iranian community. The results of this study identified that serum level of total vitamin B12 might be not different between smoking and non-smoking people, but the function of this vitamin is disturbed in the body of smokers through the reduction of serum level of active form of vitamin B12.

  15. High Prevalence of Vitamin B12 Deficiency and No Folate Deficiency in Young Children in Nepal

    Directory of Open Access Journals (Sweden)

    Bernadette N. Ng’eno

    2017-01-01

    Full Text Available Many children in low- and middle-income countries may have inadequate intake of vitamin B12 and folate; data confirming these inadequacies are limited. We used biochemical, demographic, behavioral and anthropometric data to describe the folate and vitamin B12 concentrations among six- to 23-month-old Nepalese children. Vitamin B12 (serum B12 < 150 pmol/L and folate deficiencies (red blood cell (RBC folate < 226.5 nmol/L were assessed. We used logistic regression to identify predictors of vitamin B12 deficiency. The vitamin B12 geometric mean was 186 pmol/L; 30.2% of children were deficient. The mean RBC folate concentration was 13,612 nmol/L; there was no deficiency. Factors associated with vitamin B12 deficiency included: (a age six to 11 months (adjusted odds ratio (aOR 1.51; 95% confidence interval (CI: 1.18, 1.92 or 12–17 months (aOR 1.38; 95% CI: 1.10, 1.72 compared to 18–23 months; (b being stunted (aOR 1.24; 95% CI: 1.03, 1.50 compared to not being stunted; (c and not eating animal-source foods (aOR 1.85; 95% CI: 1.42, 2.41 compared to eating animal-source foods the previous day. There was a high prevalence of vitamin B12 deficiency, but no folate deficiency. Improving early feeding practices, including the consumption of rich sources of vitamin B12, such as animal-source foods and fortified foods, may help decrease deficiency.

  16. Therapeutic role of Vitamin B12 in patients of chronic tinnitus: A pilot study

    Directory of Open Access Journals (Sweden)

    Charu Singh

    2016-01-01

    Full Text Available True tinnitus is a phantom auditory perception arising from a source or trigger in the cochlea, brainstem, or at higher centers and has no detectable acoustic generator. The most accepted is the famous neurophysiologic model of Jastreboff, which stresses that tinnitus, is a subcortical perception and results from the processing of weak neural activity in the periphery. The aim of this study is to determine the role of Vitamin B12 in treatment of chronic tinnitus. In this randomized, double-blind pilot study, total 40 patients were enrolled, of which 20 in Group A (cases received intramuscular therapy of 1 ml Vitamin B12 (2500 mcg weekly for a period of 6 weeks and Group B (20 patients received placebo isotonic saline 01 ml intramuscular. The patients were subjected to Vitamin B12 assay and audiometry pre- and post-therapy. Of the total patients of tinnitus, 17 were Vitamin B12 deficient that is 42.5% showed deficiency when the normal levels were considered to be 250 pg/ml. A paired t-test showed that in Group A, patients with Vitamin B12 deficiency showed significant improvement in mean tinnitus severity index score and visual analog scale (VAS after Vitamin B12 therapy. This pilot study highlights the significant prevalence of Vitamin B12 deficiency in North Indian population and improvement in tinnitus severity scores and VAS in cobalamin-deficient patients receiving intramuscular Vitamin B12 weekly for 6 weeks further provides a link between cobalamin deficiency and tinnitus thereby suggestive of a therapeutic role of B12 in cobalamin-deficient patients of tinnitus.

  17. Therapeutic role of Vitamin B12 in patients of chronic tinnitus: A pilot study.

    Science.gov (United States)

    Singh, Charu; Kawatra, Rahul; Gupta, Jaya; Awasthi, Vishnu; Dungana, Homnath

    2016-01-01

    True tinnitus is a phantom auditory perception arising from a source or trigger in the cochlea, brainstem, or at higher centers and has no detectable acoustic generator. The most accepted is the famous neurophysiologic model of Jastreboff, which stresses that tinnitus, is a subcortical perception and results from the processing of weak neural activity in the periphery. The aim of this study is to determine the role of Vitamin B12 in treatment of chronic tinnitus. In this randomized, double-blind pilot study, total 40 patients were enrolled, of which 20 in Group A (cases) received intramuscular therapy of 1 ml Vitamin B12 (2500 mcg) weekly for a period of 6 weeks and Group B (20) patients received placebo isotonic saline 01 ml intramuscular. The patients were subjected to Vitamin B12 assay and audiometry pre- and post-therapy. Of the total patients of tinnitus, 17 were Vitamin B12 deficient that is 42.5% showed deficiency when the normal levels were considered to be 250 pg/ml. A paired t-test showed that in Group A, patients with Vitamin B12 deficiency showed significant improvement in mean tinnitus severity index score and visual analog scale (VAS) after Vitamin B12 therapy. This pilot study highlights the significant prevalence of Vitamin B12 deficiency in North Indian population and improvement in tinnitus severity scores and VAS in cobalamin-deficient patients receiving intramuscular Vitamin B12 weekly for 6 weeks further provides a link between cobalamin deficiency and tinnitus thereby suggestive of a therapeutic role of B12 in cobalamin-deficient patients of tinnitus.

  18. Subacute combined spinal cord degeneration and pancytopenia secondary to severe vitamin B12 deficiency

    Directory of Open Access Journals (Sweden)

    José Luis Cabrerizo-García

    Full Text Available CONTEXT: Decreased vitamin B12 concentration does not usually result in clinical or hematological abnormalities. Subacute combined spinal cord degeneration and pancytopenia are two serious and rarely displayed consequences that appear in severe deficits. CASE REPORT: We present the case of a patient with subacute combined spinal cord degeneration and pancytopenia secondary to severe and sustained vitamin B12 deficiency. Such cases are rare nowadays and have potentially fatal consequences. CONCLUSIONS: Vitamin B12 deficiency should be taken into consideration in the differential diagnosis in cases of blood disorders or severe neurological symptoms. Early diagnosis and treatment can avoid irreversible consequences.

  19. Vitamin B-12 concentration, memory performance, and hippocampal structure in patients with mild cognitive impairment.

    Science.gov (United States)

    Köbe, Theresa; Witte, A Veronica; Schnelle, Ariane; Grittner, Ulrike; Tesky, Valentina A; Pantel, Johannes; Schuchardt, Jan Philipp; Hahn, Andreas; Bohlken, Jens; Rujescu, Dan; Flöel, Agnes

    2016-04-01

    Low-normal concentrations of vitamin B-12 (VitB12) may be associated with worse cognition. However, previous evidence has been mixed, and the underlying mechanisms remain unclear. We determined whether serum VitB12 concentrations within the normal range were linked to memory functions and related neuronal structures in patients with mild cognitive impairment (MCI). In a cross-sectional design, we assessed 100 amnestic MCI patients (52 women; age range: 50-80 y) with low- and high-normal VitB12 concentration (median split: 304 pmol/L) for memory functions with the use of the Auditory Verbal Learning Test. MRI was performed at 3 tesla (n= 86) for the estimation of the volume and microstructure of the hippocampus and its subfields as indicated by the mean diffusivity on diffusion-weighted images. With the use of a mediation analysis, we examined whether the relation between VitB12 and memory performance was partially explained by volume or microstructure. MCI patients with low-normal VitB12 showed a significantly poorer learning ability (P= 0.014) and recognition performance (P= 0.008) than did patients with high-normal VitB12. Also, the microstructure integrity of the hippocampus was lower in patients with low-normal VitB12, mainly in the cornu ammonis 4 and dentate gyrus region (P= 0.029), which partially mediated the effect of VitB12 on memory performance (32-48%). Adjustments for age, sex, education, apolipoprotein E e4 status, and total homocysteine, folate, and creatinine did not attenuate the effects. Low VitB12 concentrations within the normal range are associated with poorer memory performance, which is an effect that is partially mediated by the reduced microstructural integrity of the hippocampus. Future interventional trials are needed to assess whether supplementation of VitB12 may improve cognition in MCI patients even in the absence of clinically manifested VitB12 deficiency. This trial was registered at clinicaltrials.gov as NCT01219244. © 2016

  20. Genetic architecture of vitamin B12 and folate levels uncovered applying deeply sequenced large datasets

    DEFF Research Database (Denmark)

    Grarup, Niels; Sulem, Patrick; Sandholt, Camilla H

    2013-01-01

    of the underlying biology of human traits and diseases. Here, we used a large Icelandic whole genome sequence dataset combined with Danish exome sequence data to gain insight into the genetic architecture of serum levels of vitamin B12 (B12) and folate. Up to 22.9 million sequence variants were analyzed in combined...... in serum B12 or folate levels do not modify the risk of developing these conditions. Yet, the study demonstrates the value of combining whole genome and exome sequencing approaches to ascertain the genetic and molecular architectures underlying quantitative trait associations....

  1. Demencia por déficit de vitamina B12: reporte de caso

    OpenAIRE

    Junco Bonet, Miguel Damián

    2014-01-01

    Fundamento: la deficiencia de vitamina B12 (cianocobalamina) puede producir varios desórdenes neurológicos, incluida la neuropatía periférica, degeneración subaguda combinada de la médula espinal, neuropatía óptica y alteraciones cognitivas que van desde la confusión leve hasta la demencia o la psicosis. La causa más frecuente de deficiencia de vitamina B12 es la anemia perniciosa. Objetivo: presentar un caso clínico de demencia por déficit de vitamina B12. Caso clínico: paciente masculino de...

  2. Absence of a weight gain response to Vitamin B12 supplementation in weaned dairy heifers grazing pastures of marginal cobalt content.

    Science.gov (United States)

    Clark, R G; Ellison, R S; Mortleman, L; Kirk, J A; Henderson, H V

    1999-08-01

    To obtain information on serum and liver vitamin B12 and urinary methylmalonic acid concentrations as diagnostic tests to predict a weight gain response to supplementation with vitamin B12 in young dairy cattle when grazing pasture of low cobalt content. Methodology. Forty dairy cattle (12 Friesian, 14 Friesian x Jersey and 14 Jersey) were allocated to two equal sized groups, treated and untreated, based on liveweight. At monthly intervals for 14 months, all animals were weighed, their serum and urine sampled, their liver biopsied and the pasture sampled from the paddocks they were grazing and going to graze. Serum and liver were assayed for vitamin B12 concentrations. For the first 5 months of the trial, urine was assayed for methylmalonic acid concentrations. Both washed and unwashed pasture samples were assayed for cobalt concentrations. No weight gain response occurred vitamin B12 supplementation in young growing cattle grazing pasture with a cobalt concentration of 0.04-0.06 mg/kg DM. For 5 months of the trial, liver vitamin B12 concentrations from untreated calves were in the range 75-220 nmol/kg and serum vitamin B12 concentrations were as low as 72 pmol/1. There was no associated growth response to supplementation. Further trials involving young cattle grazing pastures with cobalt concentrations less than 0.04 mg/kg DM are required to reliably determine liver and serum vitamin B12 concentrations at which growth responses to vitamin B12 or cobalt supplementation are likely under New Zealand pastoral grazing conditions.

  3. [Open-path online monitoring of ambient atmospheric CO2 based on laser absorption spectrum].

    Science.gov (United States)

    He, Ying; Zhang, Yu-Jun; Kan, Rui-Feng; Xia, Hui; Geng, Hui; Ruan, Jun; Wang, Min; Cui, Xiao-Juan; Liu, Wen-Qing

    2009-01-01

    With the conjunction of tunable diode laser absorption spectroscopy technology (TDLAS) and the open long optical path technology, the system designing scheme of CO2 on-line monitoring based on near infrared tunable diode laser absorption spectroscopy technology was discussed in detail, and the instrument for large-range measurement was set up. By choosing the infrared absorption line of CO2 at 1.57 microm whose line strength is strong and suitable for measurement, the ambient atmospheric CO2 was measured continuously with a 30 s temporal resolution at an suburb site in the autumn of 2007. The diurnal atmospheric variations of CO2 and continuous monitoring results were presented. The results show that the variation in CO2 concentration has an obvious diurnal periodicity in suburb where the air is free of interference and contamination. The general characteristic of diurnal variation is that the concentration is low in the daytime and high at night, so it matches the photosynthesis trend. The instrument can detect gas concentration online with high resolution, high sensitivity, high precision, short response time and many other advantages, the monitoring requires no gas sampling, the calibration is easy, and the detection limit is about 4.2 x 10(-7). It has been proved that the system and measurement project are feasible, so it is an effective method for gas flux continuous online monitoring of large range in ecosystem based on TDLAS technology.

  4. Evanescent Wave Absorption Based Fiber Sensor for Measuring Glucose Solution Concentration

    Science.gov (United States)

    Marzuki, Ahmad; Candra Pratiwi, Arni; Suryanti, Venty

    2018-03-01

    An optical fiber sensor based on evanescent wave absorption designed for measuring glucose solution consentration was proposed. The sensor was made to detect absorbance of various wavelength in the glucose solution. The sensing element was fabricated by side polishing of multimode polymer optical fiber to form a D-shape. The sensing element was immersed in different concentration of glucoce solution. As light propagated through the optical fiber, the evanescent wave interacted with the glucose solution. Light was absorbed by the glucose solution. The larger concentration the glucose solution has, the more the evanescent wave was absorbed in particular wavelenght. Here in this paper, light absorbtion as function of glucose concentration was measured as function of wavelength (the color of LED). We have shown that the proposed sensor can demonstrated an increase of light absorption as function of glucose concentration.

  5. Molecular detection with terahertz waves based on absorption-induced transparency metamaterials

    Science.gov (United States)

    G. Rodrigo, Sergio; Martín-Moreno, L.

    2016-10-01

    A system for the detection of spectral signatures of chemical compounds at the Terahertz regime is presented. The system consists on a holey metal film whereby the presence of a given substance provokes the appearance of spectral features in transmission and reflection induced by the molecular specimen. These induced effects can be regarded as an extraordinary optical transmission phenomenon called absorption-induced transparency (AIT). The phenomenon consist precisely in the appearance of peaks in transmission and dips in reflection after sputtering of a chemical compound onto an initially opaque holey metal film. The spectral signatures due to AIT occur unexpectedly close to the absorption energies of the molecules. The presence of a target, a chemical compound, would be thus revealed as a strong drop in reflectivity measurements. We theoretically predict the AIT based system would serve to detect amounts of hydrocyanic acid (HCN) at low rate concentrations.

  6. Relationship between soil cobalt and vitamin B12 levels in the liver ...

    African Journals Online (AJOL)

    Materlais and methods: Liver and muscle tissues of livestock grazing on the selected areas were analyzed for the content ... Keywords: Soil, vitamin B12, cobalt, cattle, uptake, transfer ..... Krajcovicova-Kudlackova M, Blazicek P, Babinska K,.

  7. Svaer vitamin B12-mangel hos spaedbørn brysternaeret af veganere

    DEFF Research Database (Denmark)

    Roed, Casper; Skovby, Flemming; Lund, Allan Meldgaard

    2009-01-01

    Weight loss and reduction of motor skills resulted in paediatric evaluation of a 10-month-old girl and a 12-month-old boy. Both children suffered form anaemia and delayed development due to vitamin B12 deficiency caused by strict maternal vegan diet during pregnancy and nursing. Therapy with cyan......Weight loss and reduction of motor skills resulted in paediatric evaluation of a 10-month-old girl and a 12-month-old boy. Both children suffered form anaemia and delayed development due to vitamin B12 deficiency caused by strict maternal vegan diet during pregnancy and nursing. Therapy...... with cyanocobalamin was instituted with remission of symptoms. Since infants risk irreversible neurologic damage following severe vitamin B12 deficiency, early diagnosis and treatment are mandatory. Vegan and vegetarian women should take vitamin B12 supplementation during the pregnancy and nursing period...

  8. Relation between serum vitamin B12 level and duration of treatment with carbamazepine in epilepsy patients

    Directory of Open Access Journals (Sweden)

    Mohammad Tariqul Islam

    2016-12-01

    Full Text Available Vitamin B12 levels in the serum of 58 epileptic patients receiving only carbamazepine for at least 6 months were measured. Same number of epilepsy patients with no history of taking antiepileptic medicine were taken as control. The mean level of vitamin B12 in carbamazepine-treated epileptic patients was 265.5 pg/mL whereas it was 478.3 pg/mL in control. Increased duration of treatment of carbamazepine in epilepsy caused significantly decreased level of serum vitamin B12 (Pearson correlation coefficient, r = -0.9, p<0.0001. In conclusion, serum vitamin B12 level significantly decreased in relation to duration of carbamazepine treatment in epileptic patients.

  9. Vitamin B12 Deficiency in Persons with Intellectual Disability in a Vegetarian Residential Care Community

    Directory of Open Access Journals (Sweden)

    Mohammed Morad

    2005-01-01

    Full Text Available The goal of this study was to determine the prevalence of vitamin B12 deficiency among intellectually disabled persons in a vegetarian remedial community in Israel. In this community, 47 individuals with intellectual disability (ID live in 7 enlarged families in a kibbutz style agricultural setting. These 47 individuals and 17 of their caregivers were screened for vitamin B12 deficiency. There were 25.5% of the disabled vs. 11.8% of the caregivers found to have levels of vitamin B12 lower than 157 pg/ml. It is concluded that persons with ID in this vegetarian residential care community seemed to be at a higher risk for vitamin B12 deficiency.

  10. Study of Methionine, Vitamin B12, and Folic Acid Status in Coronary Atherosclerotic Male Patients

    OpenAIRE

    M Djalali; SR A Hoseiny; F Siassi; N Fardad; R Ghiasvand; TR Neyestani

    2007-01-01

    Background: Increased level of serum homocysteine is one of the risk factor of atherosclerosis. Its production related in some sulfur amino acids such as methionine. Some important cofactors that are involved in metabolic pathways of this amino acid are folate and vitamin B12. We have assessed the status of methionine, folic acid, and vitamin B12 in some coronary atherosclerotic male patients.Methods: In this case-control study, 46 cases of coronary atherosclerosis were selected from male pat...

  11. Development of a mechanistically based computer simulation of nitrogen oxide absorption in packed towers

    International Nuclear Information System (INIS)

    Counce, R.M.

    1981-01-01

    A computer simulation for nitrogen oxide (NO/sub x/) scrubbing in packed towers was developed for use in process design and process control. This simulation implements a mechanistically based mathematical model, which was formulated from (1) an exhaustive literature review; (2) previous NO/sub x/ scrubbing experience with sieve-plate towers; and (3) comparisons of sequential sets of experiments. Nitrogen oxide scrubbing is characterized by simultaneous absorption and desorption phenomena: the model development is based on experiments designed to feature these two phenomena. The model was then successfully tested in experiments designed to put it in jeopardy

  12. Vitamin B12 deficiency is associated with geographical latitude and solar radiation in the older population.

    Science.gov (United States)

    Cabrera, Sebastián; Benavente, David; Alvo, Miriam; de Pablo, Paola; Ferro, Charles J

    2014-11-01

    Vitamin B12 and folic acid deficiency are common in the older and are associated with several conditions including anaemia, cardiovascular disease, cognitive impairment and cancer. Evidence from in vitro studies suggests that solar radiation can degrade both vitamins in the skin. Chile is the longest country in the world running perfectly North-South making it an ideal place to study potential associations of latitude and solar radiation on vitamin B12 and folic acid deficiency. The objective was to examine the association between vitamin B12 and folic acid deficiencies and latitude. Plasma samples were collected from Chileans aged 65+ years (n=1013) living across the whole country and assayed for vitamin B12 and folic acid concentrations as part of the Chilean Health Survey 2009-2010, which is a national representative sample study. Overall, the prevalence of vitamin B12 deficiency was 11.3%, with the prevalence in the North of the country being significantly greater than in the Central and South zones (19.1%,10.5%, and 5.7%, respectively; Psolar radiation (OR 1.203 [95% confidence intervals 1.119-1.294], Psolar radiation. Although degradation by solar radiation might explain this observation, further work is required to establish the potential mechanisms. In countries that routinely fortify food with folic acid, efforts to identify vitamin B12 deficiency might be more cost-efficiently targeted in areas closest to the Equator. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Serum Homocysteine, Vitamin B12, Folic Acid Levels and Methylenetetrahydrofolate Reductase (MTHFR) Gene Polymorphism in Vitiligo

    Science.gov (United States)

    Yasar, Ali; Gunduz, Kamer; Onur, Ece; Calkan, Mehmet

    2012-01-01

    The aim of this study was to determine serum vitamin B12, folic acid and homocysteine (Hcy) levels as well as MTHFR (C677, A1298C) gene polymorphisms in patients with vitiligo, and to compare the results with healthy controls. Forty patients with vitiligo and 40 age and sex matched healthy subjects were studied. Serum vitamin B12 and folate levels were determined by enzyme-linked immunosorbent assay. Plasma Hcy levels and MTHFR polymorphisms were determined by chemiluminescence and real time PCR methods, respectively. Mean serum vitamin B12 and Hcy levels were not significantly different while folic acid levels were significantly lower in the control group. There was no significant relationship between disease activity and vitamin B12, folic acid and homocystein levels. No significant difference in C677T gene polymorphism was detected. Heterozygote A1298C gene polymorphism in the patient group was statistically higher than the control group. There was no significant relationship between MTHFR gene polymorphisms and vitamin B12, folic acid and homocysteine levels. In conclusion, vitamin B12, folate and Hcy levels are not altered in vitiligo and MTHFR gene mutations (C677T and A1298C) do not seem to create susceptibility for vitiligo. PMID:22846211

  14. Serum Homocysteine, Vitamin B12, Folic Acid Levels and Methylenetetrahydrofolate Reductase (MTHFR Gene Polymorphism in Vitiligo

    Directory of Open Access Journals (Sweden)

    Ali Yasar

    2012-01-01

    Full Text Available The aim of this study was to determine serum vitamin B12, folic acid and homocysteine (Hcy levels as well as MTHFR (C677, A1298C gene polymorphisms in patients with vitiligo, and to compare the results with healthy controls. Forty patients with vitiligo and 40 age and sex matched healthy subjects were studied. Serum vitamin B12 and folate levels were determined by enzyme-linked immunosorbent assay. Plasma Hcy levels and MTHFR polymorphisms were determined by chemiluminescence and real time PCR methods, respectively. Mean serum vitamin B12 and Hcy levels were not significantly different while folic acid levels were significantly lower in the control group. There was no significant relationship between disease activity and vitamin B12, folic acid and homocystein levels. No significant difference in C677T gene polymorphism was detected. Heterozygote A1298C gene polymorphism in the patient group was statistically higher than the control group. There was no significant relationship between MTHFR gene polymorphisms and vitamin B12, folic acid and homocysteine levels. In conclusion, vitamin B12, folate and Hcy levels are not altered in vitiligo and MTHFR gene mutations (C677T and A1298C do not seem to create susceptibility for vitiligo.

  15. Vitamin B12 deficiency is associated with cardiovascular autonomic neuropathy in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Hansen, Christian S; Jensen, Jan S; Ridderstråle, Martin

    2017-01-01

    .01; 0.43, p=0.038), and a decrease in 5min RHR of 0.25 beats per minute (95% CI -0.47; -0.03, p=0.025). CONCLUSION: Vitamin B12 may be inversely associated with CAN in patients with type 2 diabetes. Confirmatory studies investigating a causal role of vitamin B12 for the development of diabetic CAN......AIMS: Vitamin B12 deficiency could be associated with cardiovascular autonomic neuropathy (CAN) in diabetes patients. We aim to investigate the association between serum levels of vitamin B12 and CAN in type 2 diabetes patients. METHODS: 469 ambulatory type 2 diabetes patients (mean diabetes...... duration 10.0years (IQR 5.0;17.0), mean age 59.0years (SD 11.6), 63% men, mean B12 289.0pmol/l (IQR 217;390)) were screened for CAN using three cardiovascular reflex tests, five minute resting heart rate (5min RHR) and heart rate variability indices. RESULTS: Serum levels of vitamin B12 were significantly...

  16. Iron, folacin, vitamin B12 and zinc status and immune response in elderly subjects in the Washington D.C. metropolitan area

    International Nuclear Information System (INIS)

    Henry-Christian, J.R.

    1986-01-01

    The iron, folacin, vitamin B 12 , and zinc status of a group of economically and socially disadvantaged elderly persons in the Washington Metropolitan Area was evaluated. Factors related to deficiencies of these nutrients, the relationships between the status of these nutrients and cell-mediated immunity, and the relationships of iron, folacin and vitamin B 12 status to hemoglobin levels in the subjects were also examined. It was also determined whether there were any interactions among iron, folacin, vitamin B 12 and zinc status in their relationships to cell-mediated immunity. Socio-demographic and nutritional data on the subjects were obtained using a questionnaire. Dietary data were obtained using a dietary record. A fasting blood sample was drawn and the levels of ferritin, folate and vitamin B 12 , and the erythrocyte levels of folate were determined by radioassay. Plasma and hair zinc levels were determined by atomic absorption spectrophotometry. Cell-mediated immune response was determined by transformation of peripheral blood lymphocytes after stimulation by mitogens, and by allogenic lymphocytes in the mixed lymphocyte reaction

  17. Vitamin B12 Phosphate Conjugation and Its Effect on Binding to the Human B12 -Binding Proteins Intrinsic Factor and Haptocorrin

    DEFF Research Database (Denmark)

    Ó Proinsias, Keith; Ociepa, Michał; Pluta, Katarzyna

    2016-01-01

    The binding of vitamin B12 derivatives to human B12 transporter proteins is strongly influenced by the type and site of modification of the cobalamin original structure. We have prepared the first cobalamin derivative modified at the phosphate moiety. The reaction conditions were fully optimized...... and its limitations examined. The resulting derivatives, particularly those bearing terminal alkyne and azide groups, were isolated and used in copper-catalyzed alkyne-azide cycloaddition reactions (CuAAC). Their sensitivity towards light revealed their potential as photocleavable molecules. The binding...... abilities of selected derivatives were examined and compared with cyanocobalamin. The interaction of the alkylated derivatives with haptocorrin was less affected than the interaction with intrinsic factor. Furthermore, the configuration of the phosphate moiety was irrelevant to the binding process....

  18. Hydrogen absorption/desorption properties in the TiCrV based alloys

    Directory of Open Access Journals (Sweden)

    A. Martínez

    2012-10-01

    Full Text Available Three different Ti-based alloys with bcc structure and Laves phase were studied. The TiCr1.1V0.9, TiCr1.1V0.45Nb0.45 and TiCr1.1V0.9 + 4%Zr7Ni10 alloys were melted in arc furnace under argon atmosphere. The hydrogen absorption capacity was measured by using aparatus type Sievert's. Crystal structures, and the lattice parameters were determined by using X-ray diffraction, XRD. Microestructural analysis was performed by scanning electron microscope, SEM and electron dispersive X-ray, EDS. The hydrogen storage capacity attained a value of 3.6 wt. (% for TiCr1.1V0.9 alloy in a time of 9 minutes, 3.3 wt. (% for TiCr1.1V0.45Nb0.45 alloy in a time of 7 minutes and 3.6 wt. (% TiCr1.1V0.9 + 4%Zr7Ni10 with an increase of the hydrogen absorption kinetics attained in 2 minutes. This indicates that the addition of Nb and 4%Zr7Ni10 to the TiCrV alloy acts as catalysts to accelerate the hydrogen absorption kinetics.

  19. Automation of cell-based drug absorption assays in 96-well format using permeable support systems.

    Science.gov (United States)

    Larson, Brad; Banks, Peter; Sherman, Hilary; Rothenberg, Mark

    2012-06-01

    Cell-based drug absorption assays, such as Caco-2 and MDCK-MDR1, are an essential component of lead compound ADME/Tox testing. The permeability and transport data they provide can determine whether a compound continues in the drug discovery process. Current methods typically incorporate 24-well microplates and are performed manually. Yet the need to generate absorption data earlier in the drug discovery process, on an increasing number of compounds, is driving the use of higher density plates. A simple, more efficient process that incorporates 96-well permeable supports and proper instrumentation in an automated process provides more reproducible data compared to manual methods. Here we demonstrate the ability to perform drug permeability and transport assays using Caco-2 or MDCKII-MDR1 cells. The assay procedure was automated in a 96-well format, including cell seeding, media and buffer exchanges, compound dispense, and sample removal using simple robotic instrumentation. Cell monolayer integrity was confirmed via transepithelial electrical resistance and Lucifer yellow measurements. Proper cell function was validated by analyzing apical-to-basolateral and basolateral-to-apical movement of rhodamine 123, a known P-glycoprotein substrate. Apparent permeability and efflux data demonstrate how the automated procedure provides a less variable method than manual processing, and delivers a more accurate assessment of a compound's absorption characteristics.

  20. A CCD-based system for the detection of DNA in electrophoresis gels by UV absorption

    International Nuclear Information System (INIS)

    Mahon, A.R.; MacDonald, J.H.; Mainwood, A.; Ott, R.J.

    1999-01-01

    A method and apparatus for the detection and quantification of large fragments of unlabelled nucleic acids in agarose gels is presented. The technique is based on ultraviolet (UV) absorption by nucleotides. A deuterium source illuminates individual sample lanes of an electrophoresis gel via an array of optical fibres. As DNA bands pass through the illuminated region of the gel the amount of UV light transmitted is reduced because of absorption by the DNA. During electrophoresis the regions of DNA are detected on-line using a UV-sensitive charge coupled device (CCD). As the absorption coefficient is proportional to the mass of DNA the technique is inherently quantitative. The mass of DNA in a region of the gel is approximately proportional to the integrated signal in the corresponding section of the CCD image. This system currently has a detection limit of less than 1.25 ng compared with 2-10 ng for the most popular conventional technique, ethidium bromide (EtBr) staining. In addition the DNA sample remains in its native state. The removal of the carcinogenic dye from the detection procedure greatly reduces associated biological hazards. (author)

  1. Tunable Absorption System based on magnetorheological elastomers and Halbach array: design and testing

    Energy Technology Data Exchange (ETDEWEB)

    Bocian, Mirosław; Kaleta, Jerzy; Lewandowski, Daniel, E-mail: daniel.lewandowski@pwr.edu.pl; Przybylski, Michał

    2017-08-01

    Highlights: • Construction of a Tunable Absorption System incorporating MRE has been done. • For system control by magnetic field a double circular Halbach array has been used. • Significant changes of the TSAs natural frequency and damping has been obtained. - Abstract: In this paper, the systematic design, construction and testing of a Tunable Absorption System (TAS) incorporating magnetorheological elastomer (MRE) has been investigated. The TAS has been designed for energy absorption and mitigation of vibratory motions from an impact excitation. The main advantage of the designed TAS is that it has the ability to change and adapt to working conditions. Tunability can be realised through a change in the magnetic field caused by the change of an internal arrangement of permanent magnets within a double dipolar circular Halbach array. To show the capabilities of the tested system, experiments based on an impulse excitation have been performed. Significant changes of the TASs natural frequency and damping characteristics have been obtained. By incorporating magnetic tunability within the TAS a significant qualitative and quantitative change in the devices mechanical properties and performance were obtained.

  2. Photocatalytic characteristics of single phase Fe-doped anatase TiO2 nanoparticles sensitized with vitamin B12

    International Nuclear Information System (INIS)

    Gharagozlou, Mehrnaz; Bayati, R.

    2015-01-01

    Highlights: • Anatase TiO 2 /B 12 hybrid nanostructured catalyst was successfully synthesized by sol–gel technique. • The nanoparticle catalyst was doped with iron at several concentrations. • Nanoparticles were characterized in detail by XRD, Raman, TEM, EDS, and spectroscopy techniques. • The formation mechanism and role of point defects on photocatalytic properties were discussed. • A structure-property-processing correlation was established. - Abstract: We report a processing-structure-property correlation in B 12 -anatase titania hybrid catalysts doped with several concentrations of iron. Our results clearly show that low-level iron doping alters structure, defect content, and photocatalytic characteristics of TiO 2 . XRD and Raman studies revealed formation of a single-phase anatase TiO 2 where no iron based segregation in particular iron oxide, was detected. FT-IR spectra clearly confirmed sensitization of TiO 2 nanoparticles with vitamin B 12 . TEM micrographs and diffraction patterns confirmed crystallization of anatase nanoparticles with a radius of 15–20 nm. Both XRD and Raman signals showed a peak shift and a peak broadening which are surmised to originate from creation of point defects, namely oxygen vacancy and titanium interstitial. The doped samples revealed a narrower band gap as compared to undoped samples. Photocatalytic activity of the samples was assessed through measuring the decomposition rate of rhodamine B. It was found that sensitization with vitamin B 12 and Fe-doping significantly enhances the photocatalytic efficiency of the anatase nanoparticles. We also showed that there is an optimum Fe-doping level where the maximum photocatalytic activity is achieved. The boost of photocatalytic activity was qualitatively understood to originate from a more effective use of the light photons, formation of point defects, which enhance the charge separation, higher carrier mobility

  3. Satellite- and ground-based observations of atmospheric water vapor absorption in the 940 nm region

    International Nuclear Information System (INIS)

    Albert, P.; Smith, K.M.; Bennartz, R.; Newnham, D.A.; Fischer, J.

    2004-01-01

    Ground-based measurements of direct absorption of solar radiation between 9000 and 13,000 cm -1 (770-1100 nm) with a spectral resolution of 0.05 cm -1 are compared with line-by-line simulations of atmospheric absorption based on different molecular databases (HITRAN 2000, HITRAN 99, HITRAN 96 and ESA-WVR). Differences between measurements and simulations can be reduced to a great amount by scaling the individual line intensities with spectral and database dependent scaling factors. Scaling factors are calculated for the selected databases using a Marquardt non-linear least-squares fit together with a forward model for 100 cm -1 wide intervals between 10,150 and 11,250 cm -1 as well as for the water vapor absorption channels of the Medium Resolution Imaging Spectrometer (MERIS) onboard the European Space Agency's (ESA) ENVISAT platform and the Modular Optoelectronic Scanner (MOS) on the Indian IRSP-3 platform, developed by the German Aerospace Centre (DLR). For the latter, the scaling coefficients are converted into correction factors for retrieved total columnar water vapor content and used for a comparison of MOS-based retrievals of total columnar atmospheric water vapor above cloud-free land surfaces with radio soundings. The scaling factors determined for 100 cm -1 wide intervals range from 0.85 for the ESA-WVR molecular database to 1.15 for HITRAN 96. The best agreement between measurements and simulations is achieved with HITRAN 99 and HITRAN 2000, respectively, using scaling factors between 0.9 and 1. The effects on the satellite-based retrievals of columnar atmospheric water vapor range from 2% (HITRAN 2000) to 12% (ESA-WVR)

  4. Supplementing lactating dairy cows with a vitamin B12 precursor, 5,6-dimethylbenzimidazole, increases the apparent ruminal synthesis of vitamin B12.

    Science.gov (United States)

    Brito, A; Chiquette, J; Stabler, S P; Allen, R H; Girard, C L

    2015-01-01

    Cobalamin (CBL), the biologically active form of vitamin B12, and its analogs, are produced by bacteria only if cobalt supply is adequate. The analogs differ generally by the nucleotide moiety of the molecule. In CBL, 5,6-dimethylbenzimidazole (5,6-DMB) is the base in the nucleotide moiety. The present study aimed to determine if a supplement of 5,6-DMB could increase utilization of dietary cobalt for synthesis of CBL and change ruminal fermentation, nutrient digestibility, omasal flow of nutrients and ruminal protozoa counts. Eight ruminally cannulated multiparous Holstein cows (mean±standard deviation=238±21 days in milk and 736±47 kg of BW) were used in a crossover design. Cows were randomly assigned to a daily supplement of a gelatin capsule containing 1.5 g of 5,6-DMB via the rumen cannula or no supplement. Each period lasted 29 days and consisted of 21 days for treatment adaptation and 8 days for data and samples collection. Five corrinoids, CBL and four cobamides were detected in the total mixed ration and the omasal digesta from both treatments. The dietary supplement of 5,6-DMB increased (P=0.02) apparent ruminal synthesis of CBL from 14.6 to 19.6 (s.e.m. 0.8) mg/day but had no effect (P>0.1) on apparent ruminal synthesis of the four analogs. The supplement of 5,6-DMB had no effect (P>0.1) on milk production and composition, or on protozoal count, ruminal pH and concentrations of volatile fatty acids and ammonia nitrogen in rumen content. The supplement had also no effect (P>0.1) on intake, omasal flow and apparent ruminal digestibility of dry matter, organic matter, NDF, ADF and nitrogenous fractions. Plasma concentration of CBL was not affected by treatments (P=0.98). Providing a preformed part of the CBL molecule, that is, 5,6-DMB, increased by 34% the apparent ruminal synthesis of CBL by ruminal bacteria but had no effect on ruminal fermentation or protozoa count and it was not sufficient to increase plasma concentrations of the vitamin. Even though

  5. Relationship among plasma vitamin B12 and folic acid levels and coronary artery disease

    Directory of Open Access Journals (Sweden)

    Masoomeh Tohidhi

    2012-04-01

    Full Text Available Background: Hyperhomocysteinemia is a new risk factor for cardiovascular disease. It is a sensitive marker of the vitamin B12 and folate insufficiency. Folate and vitamin B12 may be a protective effect on cardiovascular disease. According to limited data about role of vitamin B12 and folate in coronary artery disease (CAD, we conducted this study to measure these factors in patients with coronary artery disease and in control subjects. Methods: This case-control study was performed on 139 subjects who underwent coronary angiography in Shiraz. Plasma vitamin B12 and folate level were measured and compared between patients with CAD and control subjects. Results: 139 individuals with a mean age 56.99±11.93 were enrolled in this study. 31.2% of them had a normal coronary angiography. Mean plasma level of folate in patients with CAD was lower than control subjects (4.46±1.28 ng/ml versus 5.00±1.81 ng/ml, P = 0.04. Also mean plasma level of vitamin B12 in patients CAD and control subjects were 451.43±138.90 and 503.60±199.35 pg/ml respectively. Although mean level of vitamin B12 in patients with CAD was lower than control group, but it was not statistically significant (P = 0.07. Conclusion: Mean plasma level of vitamin B12 and folate were lower in patients with CAD than control group. It seems that supplementation with this vitamins may be useful in patients with CAD.

  6. Efficacy of folate and vitamin B12 in lowering homocysteine concentrations in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Azadibakhsh Nassim

    2009-01-01

    Full Text Available To evaluate the efficacy of supplementation with high dose folic acid with and with-out vitamin B 12 in lowering plasma total homocysteine (tHcy concentrations in hemodialysis (HD patients, we studied 36 HD patients randomized into four groups according to the received thera-peutic regimen: group I (only folic acid (FA, 5 mg/day, group II (FA, 5 mg/day + vitamin B 12 , 1 mg/day group III (only FA, 15 mg/day, group IV (FA, 15 mg/day, vitamin B 12 , 1 mg/day for a period of 8 weeks. Plasma tHcy and serum FA and vitamin B 12 levels were measured at baseline and after the supplementation period. Dietary intakes were assessed during the study period. At baseline, 27.8% of the patients had normal levels of tHcy and 72.2% had hyperhomocysteinemia. After supplementation, plasma tHcy increased by 1.35% in group I and decreased by 6.99%, 14.54% and 30.09% in groups II, III and IV respectively, which was only significant in group IV (P= 0.014. The patients did not show any significant changes in serum folic acid, but a significant change in serum vitamin B 12 in group IV (P= 0.006. Percentage of patients reaching normal levels of plasma tHcy was 5.6 fold higher in group IV than in the reference group (group I. No corre-lations were found between changes of plasma tHcy levels and dietary intakes. We conclude that oral supplementation with 15 mg/day folic acid together with 1 mg/day of vitamin B 12 is effective in reducing tHcy levels in HD patients. These supplements also have a desirable effect on serum folic acid and vitamin B12.

  7. Trigeneration System Based on Municipal Waste Gasification, Fuel Cell and an Absorption Chiller

    DEFF Research Database (Denmark)

    Katsaros, Giannis; Nguyen, Tuong-Van; Rokni, Masoud

    2016-01-01

    of a specific building is also investigated and the system can fully meet the electricity and cooling demands, whereas the heat needs can be satisfied only up to 55%. Moreover, assuming 20 years of operation, the payback period is 4.3 years and the net present value exceeds 5 MEUR.......The present work focuses on the design of a novel tri-generation system based on municipal solid wastes gasification, solid oxide fuel cell and an ammonia-water absorption chiller. Trigeneration systems can be implemented in buildings such as hospitals, where there is a continuous and large demand...

  8. Si Substrate-Based Meta materials for Ultra broadband Perfect Absorption in Visible Regime

    International Nuclear Information System (INIS)

    Han, Q.; Jin, L.; Fu, Y.; Yu, W.; Yu, W.

    2014-01-01

    We report the broadband efficient light absorbing property of a structure of quadrangular frustum pyramid array in visible regime. The structure can absorb light efficiently with an average absorptivity of 0.98 over the whole visible waveband. In addition, it is found that this kind of super light absorbing can maintain an average of 0.9 for a wide incident angle range. The perfect absorbing property of the meta material-based nano ring array is attributed to the effect of the Fabry-Perot resonance. The structure is possible to be used as a type of Si photonics devices in future photonic circuits

  9. Study Of Soot Growth And Nucleation By A Time-Resolved Synchrotron Radiation Based X-Ray Absorption Method

    National Research Council Canada - National Science Library

    Mitchell, Judith I

    2001-01-01

    This report results from a contract tasking University of Rennes I as follows: The contractor will perform a study of soot growth and nucleation by a time-resolved synchrotron radiation based x-ray absorption method...

  10. Studies on the biosynthesis of vitamin B2 and vitamin B12

    International Nuclear Information System (INIS)

    Chen, H.C.

    1988-01-01

    Feeding experiments with Ashbya gossypii followed by NMR analysis of the resulting riboflavin showed incorporation of deuterium from D-[2- 2 H]ribose at C-2' and from D-[1- 2 H]ribose in the pro-R position at C-1' of the ribityl side chain. The results rule out an Amadori rearrangement mechanism for the reduction of the ribosylamino to the ribitylamino linkage and point to formation of a Schiff base that is reduced stereospecifically opposite to the face from which the oxygen has departed. As prerequisite for the analysis, the 1 H NMR signals for the pro-R and pro-S hydrogens at C-1' of riboflavin and its tetraacetate were assigned with the aid of synthetic stereospecifically deuteriated samples. Feeding experiments with Propionibacterium shermianii followed by NMR analysis of the resulting vitamin B 12 showed: (1) 5-methylbenzimidazole (5MBI) incorporated and only one regioisomer (B6-demethylcyanocobalamin)formed. (2) 8-demethylriboflavin incorporated and the same regioisomer was obtained as 5MBI experiment. (3) [1'- 13 C, 5- 15 N]riboflavin incorporated and 13 C-NMR showed that 13 C at the B2 position of cyanocobalamin coupled to both adjacent nitrogen-15 atoms at about the same ratio

  11. Plasma Folate and Vitamin B12 Levels in Patients with Hepatocellular Carcinoma

    Directory of Open Access Journals (Sweden)

    Lian-Hua Cui

    2016-06-01

    Full Text Available Folate and vitamin B12 involved in the one-carbon metabolism may play a key role in carcinogenesis and progression of hepatocellular carcinoma (HCC through influencing DNA integrity. The purpose of this study is to evaluate the association of plasma folate and vitamin B12 levels with HCC in a case-control study on 312 HCC patients and 325 cancer-free controls. Plasma concentrations of folate and vitamin B12 in all the subjects were measured by electrochemiluminescence immunoassay. Meanwhile, the information of HCC patients’ clinical characteristics including tumor-node-metastasis (TNM stage, tumor size and tumor markers were collected. The patients of HCC had significantly lower folate levels than those of controls; there was no significant difference in the mean of plasma vitamin B12 levels. We also observed an inverse association between the levels of plasma folate and HCC: the adjusted odds ratios (OR (95% confidence intervals (CI of HCC from the highest to lowest quartile of folate were 0.30 (0.15–0.60, 0.33 (0.17–0.65, and 0.19 (0.09–0.38. Compared to the subjects in the lowest quartile of plasma vitamin B12, only the subjects in the highest quartile of vitamin B12 exhibited a significant positive relationship with HCC, the adjusted OR was 2.01 (95% CI, 1.02–3.98. HCC patients with Stage III and IV or bigger tumor size had lower folate and higher vitamin B12 levels. There was no significant difference in the mean plasma folate levels of the HCC cases in tumor markers status (AFP, CEA and CA19-9 levels, whereas patients with higher CEA or CA19-9 levels retained significantly more plasma vitamin B12 than those with normal-CEA or CA19-9 level. In conclusion, plasma folate and vitamin B12 levels could be associated with HCC, and might be used as predictors of clinical characteristics of HCC patients. However, further prospective studies are essential to confirm the observed results.

  12. Serum vitamin B12, folic acid and ferritin levels in patients with migraine

    Directory of Open Access Journals (Sweden)

    Abdullah Acar

    2011-06-01

    Full Text Available OBJECTIVE: It has been reported that disability due to migraine may be reduced with homocysteine-lowering treatment including folic acid and vitamin B12. In addition, recently the periaqueductal gray matter iron deposits have been found to be increased in migraine patients. There are few studies regarding vitamin B12, folic acid, ferritin and transferrin levels in patients with migraine. The aims of this study was to measure vitamin B12, folic acid, ferritin and transferrin levels in patients with migraine and compare them with the control group. METHODS: Fifty-one consecutive newly diagnosed migraine patients who did not receive any vitamin supplement medication were enrolled. The study group consisted of 51 patients, suffering from migraine with aura (n= 23 and migraine without aura (n= 28. The control group consisted of 28 healthy participants without history of headache, anemia and vitamin supplement. Serum vitamin B12, folic acid, ferritin and transferin levels were measured using a chemiluminescence method. RESULTS: Migraine patients had significantly lower concentrations of vitamin B12 and folic acid compared with the healthy controls (for vitamin B12; 215.6±133.7 pg/ml vs. 289.9±12 pg/ml, respectively, p=0.005; for folic acid; 6.74 ± 4.31 pg/ml vs. 8.47 ± 1.85 pg/ml, respectively, p=0.048. The vitamin B12 levels were found to be significantly lower during attacks in migraine patients than in interictal periods (177.3 ± 139.2 pg/ml vs 252.5 ± 119.5 pg/ml, p=0.043. There were no differences in folic acid, ferritin, and transferritin levels between during attacks and in interictal period of patients with migraine (p>0.05. The ferritin levels were found to be significantly lower during attacks in migraine patients than in interictal periods (43.4 ± 41.1 mg/ml, vs 75.4 ± 51.7, mg/ml, p=0.018. CONCLUSION: Migraine patients had lower serum vitamin B12 and folic acid levels than healthy subjects. These findings supported that vitamin B12

  13. Advanced cogeneration and absorption chillers potential for service to Navy bases. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, J.W.; Butcher, T.A.; Leigh, R.W.; McDonald, R.J.; Pierce, B.L.

    1996-04-01

    The US military uses millions of Btu`s of thermal energy to heat, cool and deliver process thermal energy to buildings on military bases, much of which is transmitted through a pipeline system incorporating thousands of miles of pipe. Much of this pipeline system is in disrepair and is nearing the end of its useful life, and the boilers which supply it are old and often inefficient. In 1993, Brookhaven National Laboratory (BNL) proposed to SERDP a three-year effort to develop advanced systems of coupled diesel cogenerators and absorption chillers which would be particularly useful in providing a continuation of the services now provided by increasingly antiquated district systems. In mid-February, 1995, BNL learned that all subsequent funding for our program had been canceled. BNL staff continued to develop the Program Plan and to adhere to the requirements of the Execution Plan, but began to look for ways in which the work could be made relevant to Navy and DoD energy needs even without the extensive development plan formerly envisioned. The entire program was therefore re-oriented to look for ways in which small scale cogeneration and absorption chilling technologies, available through procurement rather than development, could provide some solutions to the problem of deteriorated district heating systems. The result is, we believe, a striking new approach to the provision of building services on military bases: in many cases, serious study should be made of the possibility that the old district heating system should be removed or abandoned, and small-scale cogenerators and absorption chillers should be installed in each building. In the remainder of this Summary, we develop the rationale behind this concept and summarize our findings concerning the conditions under which this course of action would be advisable and the economic benefits which will accrue if it is followed. The details are developed in the succeeding sections of the report.

  14. Combined indicator of vitamin B 12 status: modification for missing biomarkers and folate status and recommendations for revised cut-points

    Science.gov (United States)

    Background: A novel approach to determine vitamin B 12 status is to combine four blood markers: total B 12 (B 12 ), holotranscobalamin (holoTC), methylmalonic acid (MMA) and total homocysteine (tHcy). This combined indicator of B 12 status is expressed as cB 12 = log 10 [(holoTC · B 12 )/ (MMA · Hcy...

  15. Effects of folate and vitamin B12 deficiencies during pregnancy on fetal, infant, and child development.

    Science.gov (United States)

    Molloy, Anne M; Kirke, Peadar N; Brody, Lawrence C; Scott, John M; Mills, James L

    2008-06-01

    The importance of folate in reproduction can be appreciated by considering that the existence of the vitamin was first suspected from efforts to explain a potentially fatal megaloblastic anemia in young pregnant women in India. Today, low maternal folate status during pregnancy and lactation remains a significant cause of maternal morbidity in some communities. The folate status of the neonate tends to be protected at the expense of maternal stores; nevertheless, there is mounting evidence that inadequate maternal folate status during pregnancy may lead to low infant birthweight, thereby conferring risk of developmental and long-term adverse health outcomes. Moreover, folate-related anemia during childhood and adolescence might predispose children to further infections and disease. The role of folic acid in prevention of neural tube defects (NTD) is now established, and several studies suggest that this protection may extend to some other birth defects. In terms of maternal health, clinical vitamin B12 deficiency may be a cause of infertility or recurrent spontaneous abortion. Starting pregnancy with an inadequate vitamin B12 status may increase risk of birth defects such as NTD, and may contribute to preterm delivery, although this needs further evaluation. Furthermore, inadequate vitamin B12 status in the mother may lead to frank deficiency in the infant if sufficient fetal stores of vitamin B12 are not laid down during pregnancy or are not available in breastmilk. However, the implications of starting pregnancy and lactation with low vitamin B12 status have not been sufficiently researched.

  16. [Vitamin B12 levels in the patient population attending an urban health centre in Madrid].

    Science.gov (United States)

    Camarero-Shelly, M

    2018-04-01

    Vitamin B 12 levels are usually measured in Primary Care when the patients have symptoms or risk factors associated with its deficiency, mostly in the elderly. However, no evidence has been found to support the recommendation of screening in the general population. The aim of this study is to assess the relevance of having extended the screening of vitamin B 12 deficiency to a younger population, after observing an increase in the prescription of this injected vitamin in a population under 65 years, by analysing the vitamin B 12 values obtained. A descriptive, retrospective, observational study was conducted on a sample consisting of 5,531 patients from Barajas Health Primary Centre, Madrid, between 2008 and 2012, and on whom a blood test was performed for any reason, with values of vitamin B 12 . A deficiency was found in 9.1% (SD 2.3) of the patients, of whom 49.4% were less than 65 years. The deficiencies were associated (P<.001, 95% CI) with age, dementia, changes in blood red cell counts, memory, and with the taking of metformin and proton pump inhibitors (P=.007). The prevalence of vitamin B 12 deficiency in our served population is similar in patients older and younger than 65 years. The extended screening was relevant. Copyright © 2017 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Intergenotypic variation of Vitamin B12 and Folate in AD: In north Indian population

    Directory of Open Access Journals (Sweden)

    Neelam Chhillar

    2014-01-01

    Full Text Available Objectives: Changes in lifestyle habits such as diet modification or supplementation have been indicated as probable protective factors for a number of chronic conditions including Alzheimer′s disease (AD. With this background, we aim to hypothesize that whether C677T polymorphism of methylenetetrahydrofolate reductase (MTHFR gene contributes towards the risk of developing AD and its association with vitamin B12 and folate levels. Materials and Methods: A case-control study comprising of total 200 subjects, within the age group of 50-85 years. Their blood samples were analyzed for serum folate, vitamin B12 levels, and MTHFR C677T polymorphism by restriction fragment length polymorphism (RFLP. Results: The mean plasma levels of vitamin B12 and folate were significantly lower in study group when compared to the control group (P < 0.001. Genotypic and allelic frequency of MTHFR gene in both groups was found to be significant (P < 0.05. The intergenotypic variations of vitamin B12 and folate were found to be significant (P < 0.001. Conclusion: We concluded that the subjects with homozygous mutated alleles are more prone to AD and also pointed out the influence of presence/absence of MTHFR T allelic variants on serum folate and vitamin B12 levels.

  18. Analytical electrochemistry of vitamin B12 on a bismuth-film electrode surface

    International Nuclear Information System (INIS)

    Kreft, Gabriel L.; Braga, Otoniel C. de; Spinelli, Almir

    2012-01-01

    Cyclic voltammetry (CV) and square wave adsorptive stripping voltammetry (SWAdSV) were used to investigate the performance of an ex situ plated bismuth-film electrode (BiFE) employed to study the electrochemical behavior and the electroanalytical determination of vitamin B 12 . Two pH-dependent reversible peaks were observed for the B 12r –B 12s (Co(II)–Co(I)) couple after pre-concentration of vitamin B 12 at −1.2 V for 30 s. An adsorption-controlled reaction rate with one electron involved in the electrochemical step was observed for the mechanism implicated. The calibration curve obtained in a Britton–Robinson solution at pH 12.0 was linear in the concentration range of 0.100–1.000 μmol L −1 (r = 0.9980). The detection limit was found to be 33.1 nmol L −1 . The electrode was successfully employed for the determination of vitamin B 12 in two pharmaceutical products. The electrode performance was compared with those of modified and unmodified electrodes as well as with the UV–vis spectrophotometric method.

  19. Treatment of radiation skin lesions in various stages with different preparations of vitamin B12

    International Nuclear Information System (INIS)

    Ji Hui; Chen Qiang; Yang Xiaohong

    1989-01-01

    Since the aqueous solution of Vit. B 12 was firstly used to treat efficaciously the acute radiation injury of skin and superficial second-degree skin burn, we have successfully treated radiation skin lesions in acute, chronic and recovering stages with the cream or oil preparation of Vit. B 12 . In the period of ten years (1979-1988), altogether 418 cases of radiation or non-radiation skin injury were observed and 48 out of 49 cases with acute radiation skin ulcer treated with aqueous solution of Vit. B 12 were healed with an effective rate of 97.95% and average healing time of 12.6 days. All of 37 cases with chronic radiation skin injury treated with oil preparation of Vit. B 12 were healed or improved with an effective rate of 100% and average healing time of 21.49 days. However, in the control group, of 18 cases treated with conventional drugs only 13 were healed, the effective rate being 72.22% and healing time 63.5 days, and both of these indices were of significant difference, as compared with those treated with Vit. B 12

  20. Use of vitamin B12 radioassay in the analysis of biological materials, mainly of foods

    International Nuclear Information System (INIS)

    Kralova, B.; Rauch, P.; Cerna, J.

    1982-01-01

    Vitamin B 12 was determined in biological materials by three basically different methods: microbiological assay with Lactobacillus leichmannii, microbiological assay with Escherichia coli and radioassay. The method with E. coli has a relatively low sensitivity to vitamin B 12 and in some cases of vitamin B 12 determination in microbial materials it can be used only after a separation of the interfering substances by gel chromatography. The procedure is suitable for orientational determinations of vitamin B 12 because it is very little affected by external factors. The assay with L. leichmannii is universal owing to its high specifity and sensitivity to vitamin B 12 . The main disadvantage of the latter procedure depends on the high requirements for a clean atmosphere which can be maintained in laboratories in industrial areas only with difficulties. These limitations do not apply to the quick and sensitive radioassay. The radioassay can be used after a suitable adjustment of the working procedure for large series of analyses of biological materials without any preliminary separational techniques. (author)

  1. Characterization of extracellular vitamin B12 producing Lactobacillus plantarum strains and assessment of the probiotic potentials.

    Science.gov (United States)

    Li, Ping; Gu, Qing; Yang, Lanlan; Yu, Yue; Wang, Yuejiao

    2017-11-01

    We investigated extracellular vitamin B 12 -producing Lactobacillus strains and their characteristics in tolerance to environmental stresses, gastric acid and bile salts. Two isolates, Lactobacillus plantarum LZ95 and CY2, showed high extracellular B 12 production, 98±15μg/L and 60±9μg/L respectively. Extracellular B 12 from LZ95 were identified as adenosylcobalamin and methylcobalamin using a combination of solid phase extraction and reverse-phase HPLC, while that from CY2 was adenosylcobalamin. Both strains grew under environmental stresses, and LZ95 exhibited better tolerance to low temperature and high ethanol concentration. LZ95 also showed good viability when exposed to gastric acid (pH 2.0 and 3.0) and bile salts (0.3%) as well as good adhesion to Caco-2 cells. The viability of CY2 was significantly reduced under low pH and exposure to bile salt. Together, extracellular B 12 producer LZ95 with good probiotic properties might be a candidate for in situ B 12 fortification in the food industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Vitamin B12–dependent taurine synthesis regulates growth and bone mass

    Science.gov (United States)

    Roman-Garcia, Pablo; Quiros-Gonzalez, Isabel; Mottram, Lynda; Lieben, Liesbet; Sharan, Kunal; Wangwiwatsin, Arporn; Tubio, Jose; Lewis, Kirsty; Wilkinson, Debbie; Santhanam, Balaji; Sarper, Nazan; Clare, Simon; Vassiliou, George S.; Velagapudi, Vidya R.; Dougan, Gordon; Yadav, Vijay K.

    2014-01-01

    Both maternal and offspring-derived factors contribute to lifelong growth and bone mass accrual, although the specific role of maternal deficiencies in the growth and bone mass of offspring is poorly understood. In the present study, we have shown that vitamin B12 (B12) deficiency in a murine genetic model results in severe postweaning growth retardation and osteoporosis, and the severity and time of onset of this phenotype in the offspring depends on the maternal genotype. Using integrated physiological and metabolomic analysis, we determined that B12 deficiency in the offspring decreases liver taurine production and associates with abrogation of a growth hormone/insulin-like growth factor 1 (GH/IGF1) axis. Taurine increased GH-dependent IGF1 synthesis in the liver, which subsequently enhanced osteoblast function, and in B12-deficient offspring, oral administration of taurine rescued their growth retardation and osteoporosis phenotypes. These results identify B12 as an essential vitamin that positively regulates postweaning growth and bone formation through taurine synthesis and suggests potential therapies to increase bone mass. PMID:24911144

  3. Stability of added and in situ-produced vitamin B12 in breadmaking.

    Science.gov (United States)

    Edelmann, Minnamari; Chamlagain, Bhawani; Santin, Marco; Kariluoto, Susanna; Piironen, Vieno

    2016-08-01

    Vitamin B12 exists naturally in foods of animal origin and is synthesised only by certain bacteria. New food sources are needed to ensure vitamin B12 intake in risk groups. This study aimed to investigate the stability of added cyanocobalamin (CNCbl, chemically modified form) and hydroxocobalamin (OHCbl, natural form) and in situ-synthesised vitamin B12 in breadmaking. Samples were analysed both with a microbiological (MBA) and a liquid chromatographic (UHPLC) method to test applicability of these two methods. Proofing did not affect CNCbl and OHCbl levels. By contrast, 21% and 31% of OHCbl was lost in oven-baking steps in straight- and sponge-dough processes, respectively, whereas CNCbl remained almost stable. In sourdough baking, 23% of CNCbl and 44% of OHCbl were lost. In situ-produced vitamin B12 was almost as stable as added CNCbl and more stable than OHCbl. The UHPLC method showed its superiority to the MBA in determining the active vitamin B12. Copyright © 2016. Published by Elsevier Ltd.

  4. Associations between Vitamin B-12 Status and Oxidative Stress and Inflammation in Diabetic Vegetarians and Omnivores.

    Science.gov (United States)

    Lee, Yau-Jiunn; Wang, Ming-Yang; Lin, Mon-Chiou; Lin, Ping-Ting

    2016-02-26

    Diabetes is considered an oxidative stress and a chronic inflammatory disease. The purpose of this study was to investigate the correlations between vitamin B-12 status and oxidative stress and inflammation in diabetic vegetarians and omnivores. We enrolled 154 patients with type 2 diabetes (54 vegetarians and 100 omnivores). Levels of fasting glucose, glycohemoglobin (HbA1c), lipid profiles, oxidative stress, antioxidant enzymes activity, and inflammatory makers were measured. Diabetic vegetarians with higher levels of vitamin B-12 (>250 pmol/L) had significantly lower levels of fasting glucose, HbA1c and higher antioxidant enzyme activity (catalase) than those with lower levels of vitamin B-12 (≤ 250 pmol/L). A significant association was found between vitamin B-12 status and fasting glucose (r = -0.17, p = 0.03), HbA1c (r = -0.33, p = 0.02), oxidative stress (oxidized low density lipoprotein-cholesterol, r = -0.19, p = 0.03), and antioxidant enzyme activity (catalase, r = 0.28, p = 0.01) in the diabetic vegetarians; vitamin B-12 status was significantly correlated with inflammatory markers (interleukin-6, r = -0.33, p vegetarian diet.

  5. Purification and characterization of nattokinase from Bacillus subtilis natto B-12.

    Science.gov (United States)

    Wang, Cong; Du, Ming; Zheng, Dongmei; Kong, Fandong; Zu, Guoren; Feng, Yibing

    2009-10-28

    Bacillus subtilis natto B-12 was isolated from natto, a traditional fermented soybean food in Japan. A fibrinolytic enzyme (B-12 nattokinase) was purified from the supernatant of B. subtilis natto B-12 culture broth and showed strong fibrinolytic activity. The enzyme was homogenously purified to 56.1-fold, with a recovery of 43.2% of the initial activity. B-12 nattokinase was demonstrated to be homogeneous by SDS-PAGE and was identified as a monomer of 29000 +/- 300 Da in its native state by SDS-PAGE and size exclusion methods. The optimal pH value and temperature were 8.0 and 40 degrees C, respectively. Purified nattokinase showed high thermostability at temperatures from 30 to 50 degrees C and alkaline stability within the range of pH 6.0-9.0. The enzyme activity was activated by Zn(2+) and obviously inhibited by Fe(3+) and Al(3+). This study provides some important information for the effect factors of fibrinolytic activity, the purification methods, and characterization of nattokinase from B. subtilis natto B-12, which enriches the theoretical information of nattokinase for the research and development of nattokinase as a functional additive of food.

  6. Vitamin B12 Deficiency Presenting as Pancytopenia in Pregnancy: A Case Report

    Directory of Open Access Journals (Sweden)

    Idris N

    2012-12-01

    Full Text Available Vitamin B12 deficiency is a well-known cause of megaloblastic anaemia and pancytopenia. However, the incidence in pregnancy is rarely reported. We present a case of a 32-year old multigravid woman who was diagnosed with megaloblastic anaemia since 22 weeks gestation and progressed to develop severe pancytopenia at 30 weeks gestation. she was also diagnosed with vitamin B12 deficiency related to dietary and sociocultural habits. Folate and iron levels were normal throughout pregnancy. treatment with parenteral cyano-cobalamin resulted in sustained improvement of haematological parameters. the pregnancy was carried to term and the baby was born weighing 2,050gm but otherwise well at birth and had normal developmental milestones thereafter. this case illustrates the clinical presentation of maternal vitamin B12 deficiency and demonstrates the importance of detecting and treating maternal vitamin B12 deficiency during pregnancy in at-risk patients. Failure to diagnose and institute treatment carries significant risks to both mother and child. oral vitamin B12 supplementation should be considered for patients who are strict vegetarians or consume very little animal products.

  7. Clinical Significances of Serum Vitamin B12, Folate and Ferritin Levels in Patients with Malignant Tumors

    International Nuclear Information System (INIS)

    Monn, Youn Sung; Soung, In Whan; Kim, Sam Yong; Ro, Heung Kyu; Lee, Bok Hee

    1987-01-01

    In order to evaluate the clinical significances of the serum vitamin B 12 , folate and ferritin levels in patients with malignant tumors, the levels were measured in 10 normal control subjects, 70 patients with malignant tumors, 7 patients with liver cirrhosis and 25 patients with other benign diseases. The results are as follows: 1) In normal control subjects, mean serum values for vitamin B 12 , folate and ferritin level were 588.80±131.58 pg/ml, 5.59±1.52 ng/ml and 89.22±42.78 ng/ml retrospectively. 2) There was no significant difference in serum levels between patients with benign diseases and normal control subjects. 3) The serum vitamin B 12 and ferritin levels in patients with liver cirrhosis were significantly higher than in normal control, and the serum folate levels in these patients were lower than in normal control subjects. 4) The serum vitamin B 12 and ferritin levels in patients with malignant tumors were significantly higher than in normal control subjects, and the serum folate levels in these patients were significantly lower than in normal control subjects. The above results suggest that the serum vitamin B 12 and ferritin may be useful as tumor markers in patients with malignant tumors.

  8. Vitamin B-12 concentrations in breast milk are low and are not associated with reported household hunger, recent animal source food or vitamin B-12 intake among women in rural Kenya

    Science.gov (United States)

    Background: Breastmilk vitamin B-12 concentration may be inadequate in mothers living in regions where animal source food consumption is low or infrequent. Vitamin B-12 deficiency causes megaloglastic anemia and impairs growth and development in children. Objective: To measure vitamin B-12 in breast...

  9. Sensory Neuronopathy Revealing Severe Vitamin B12 Deficiency in a Patient with Anorexia Nervosa: An Often-Forgotten Reversible Cause

    Directory of Open Access Journals (Sweden)

    Jérôme Franques

    2017-03-01

    Full Text Available Vitamin B12 (B12 deficiency is known to be associated with various neurological manifestations. Although central manifestations such as dementia or subacute combined degeneration are the most classic, neurological manifestations also include sensory neuropathies. However, B12 deficiency is still rarely integrated as a potential cause of sensory neuronopathy. Moreover, as many medical conditions can falsely normalize serum B12 levels even in the context of a real B12 deficiency, some cases may easily remain underdiagnosed. We report the illustrating case of an anorexic patient with sensory neuronopathy and consistently normal serum B12 levels. After all classical causes of sensory neuronopathy were ruled out, her clinical and electrophysiological conditions first worsened after folate administration, but finally improved dramatically after B12 administration. B12 deficiency should be systematically part of the etiologic workup of sensory neuronopathy, especially in a high risk context such as anorexia nervosa.

  10. A first-principles study on the adsorption behavior of amphetamine on pristine, P- and Al-doped B12N12 nano-cages

    Science.gov (United States)

    Bahrami, Aidin; Seidi, Shahram; Baheri, Tahmineh; Aghamohammadi, Mohammad

    2013-12-01

    The first-principles computations using density functional theory (DFT) calculations at the M062X/6-311++G** level have been applied to scrutinize the adsorption behavior of amphetamine (AMP) molecule on the external surface of pristine, P- and Al-doped B12N12 nano-cages. In order to gain insight into the binding features of pristine and doped B12N12 complexes as adsorbent with AMP, the structural and electronic parameters as well as the Atoms in Molecules (AIM) properties were examined. The results showed that AMP prefers to adsorb via its nitrogen atom on the Lewis acid sites of B and Al atoms of the nano-cages. On the basis of calculated density of states, the interaction of AMP with the external wall of B12N12 leads to the remarkable differences in their conductivities. Presence of polar solvent increases the AMP adsorption on the nano-cage. In addition, AIM based analyses indicated an electrostatic nature for N-B interaction in Amph-B12N12 and partial covalent for N-Al in AMP-B11AlN12. Based on calculated results, the B12N12 and B11AlN12 nano-cages are expected to be a potential efficient adsorbent as well as sensors for adsorption of AMP in environmental systems.

  11. Optimization study of distillation column based on Type I absorption heat pump

    International Nuclear Information System (INIS)

    Li, Yan; Wang, Lu; Zhu, Meng; Wang, Weiqin

    2017-01-01

    Highlights: • Propose a new distillation system based on Type I absorption heat pump. • The optimum condition of the system is obtained. • The energy consumption of the system is reduced by 23.3% significantly. • The benefits of economy and energy-saving for the new distillation system are distinct. - Abstract: Due to the thermodynamic deficiencies in general pressurized distillation process, a new distillation system based on Type I AHP (absorption heat pump) is proposed in this paper. The proposed system uses AHP to recover the waste heat from column condenser and reheat the feed materials of column; meanwhile, the cooling capacity of column condenser can be increased, which leads to the decrease of the pressure in distillation column. With general distillation system of depropanizing column (C-101) as an example, using numerical simulation software Aspen Plus, the effect of inner parameters on the energy consumption has been conducted to approach the general rules of energy saving in distillation. Then the new distillation system is adopted and the optimization of its energy consumption is conducted to determine the optimum operating condition. The numerical simulation results show that the steam consumption can be decreased by 23.3% compared with general C-101 system, reaching the minimum. Moreover, the extra heat output of AHP is treated as the heat source for the reboilers of deethanization column (C-102) and refined propylene column (C-103), which reduces the total steam consumption of three-column processes by 22.1%.

  12. Quantitative materials analysis of micro devices using absorption-based thickness measurements

    International Nuclear Information System (INIS)

    Sim, L M; Wog, B S; Spowage, A C

    2006-01-01

    Preliminary work in designing an X-ray inspection machine with the capability of providing quantitative thickness analysis based on absorption measurements has been demonstrated. This study attempts to use the gray levels data to investigate the nature and thickness of occluded features and materials within devices. The investigation focused on metallic materials essential to semiconductor and MEMS technologies such as tin, aluminium, copper, silver, iron and zinc. The materials were arranged to simulate different feature thicknesses and sample geometries. The X-ray parameters were varied in-order to modify the X-ray energy spectrum with the aim of optimising the measurement conditions for each sample. The capability of the method to resolve differences in thicknesses was found to be highly dependent on the material. The thickness resolution with aluminium was the poorest due to its low radiographic density. The thickness resolutions achievable for silver and tin were significantly better and of the order of 0.015 mm and 0.025 mm respectively. From the linear relationship between the X-ray attenuation and sample thickness established, the energy dependent linear attenuation coefficient for each material was determined for a series of specific energy spectra. A decrease in the linear attenuation coefficient was observed as the applied voltage and thickness of the material increased. The results provide a platform for the development of a novel absorption-based thickness measurement system that can be optimised for a range of industrial applications

  13. The relationship between cerebrovascular disease and homocysteine, folate and vitamin B12 in serum

    International Nuclear Information System (INIS)

    Wang Wei; Yang Chen; Shi Yizhen; Liu Zengli

    2005-01-01

    To investigate the relationship between cerebrovascular disease and the serum levels of homocysteine(Hcy), folate and vitamin B 12 , the serum levels of Hcy, folate and vitamin B 12 in 148 patients with cerebrovascular disease were measured by fluorescence polarization immuno- assay and chemiluminescence and were compared with those in healthy controls. The result showed that the serum Hcy levels in patients with cerebral infarction, cerebral hemorrhage and vertebrobasilar ischemiay were significantly higher than those in healthy controls (P 12 levels were signifieantly lower (P 0.05). No significantly higher ratio of increased Hcy levels was observed in patient with complications (P> 0.05). Our conclusion is that hyperhomocysteinemia may be a new and an independent risk factor for cerebrovascular disease. The serum Hcy level is correlated with decreased levels of folate and vitamin B 12 but not obviously correlated with hypertension, diabetes and coronary heart disease. (authors)

  14. Clinical observation of vitamin B12 eye drops for vision fatigue caused by visual display terminals

    Directory of Open Access Journals (Sweden)

    Qiang Guo

    2016-07-01

    Full Text Available AIM: To investigate the clinical effect of vitamin B12 eye drops for vision fatigue caused by visual display terminals(VDT. METHODS: Totally 50 patients(100 eyeswith vision fatigue caused by VDT were averagely divided into two groups. The control group were treated with normal saline,the treatment group were treated with vitamin B12 eye drops,3 times per day, one drop each time, continuous for 60d. Accommodative parameters and Schirmer Ⅰtest were measured and analyzed before and after treatment. RESULTS:After treatment, the results of Schirmer Ⅰtest, accommodative amplitude and accommodative facility of the treatment group were higher than those of the control group(all PPCONCLUSION: Vitamin B12 eye drops can lessen symptoms of dry eye, improve accommodative function and treat vision fatigue caused by VDT.

  15. Vitamin B12 and folate levels in normal population of northern Pakistan

    International Nuclear Information System (INIS)

    Madood-ul-mannan; Anwar, M.; Saleem, M.; Waqar, A.; Ahmad, M.

    1990-01-01

    Diagnosis of vitamin B12 or folate deficiency can not be made unless reference ranges of these vitamins in a given population are known. These serum levels depend upon the dietary intake of these vitamins which in turn depends upon the availability of foods containing these vitamins and the methods of cooking/processing. The latter vary in different populations. Therefore serum level of these vitamins would vary in different populations. Serum levels of vitamin B12 and folate were estimated by radioimmunoassay technique in 30 normal subjects of different age groups. The levels of vitamin B12 were found to be 215.2 pg/ml and that of folate 3.9 ng/ml. These values are much lower than those described for European population. It is therefore concluded that the cut off point of the levels of these vitamins should be different than the European figures. (author)

  16. Vitamin B12-catalyzed synthesis of some peracetylated alkyl b-D-xylopyranosides

    Directory of Open Access Journals (Sweden)

    LJILJANA STEVANOVIC

    2003-10-01

    Full Text Available The vitamin B12-catalyzed glycosylation reaction of brominated b-D-xylose peracetate with alkanols ROH (C1-C8 has been studied. The catalytically active species in this reaction was cob(Ialamin, obtained by chemical reduction of Vitamin B12 with NaBH4 (Co(III to Co(I. The reaction was carried out with 2 mol% of vitamin B12, with respect to xylosyl bromide 1, under argon at room temperature. Under these conditions, peracetylated C1-C8-alkyl b-D-xylopyranosides (3a–3f were obtained in moderate yield (55–70 %. In all cases 3,4-di-O-acetyl-D-xylal (4 was obtained, as the product of reductive elimination of peracetylated xylosyl bromide (15–25 %.

  17. Perspective of Chinese Forest Carbon Absorption Trade Based on Low-Carbon Economy

    OpenAIRE

    Wang, Ming-gang

    2011-01-01

    The paper analyzes the basis of forest carbon trade including me feasibility of carbon absorption trade, main body, platform and standard. The purposes of capital of carbon absorption trade is introduced. Caron absorption trade capital can be used to resettle ecological migrants, absorb employment, build forest and increase fund, increase local income, enhance forest science and technology development and launch environmental proportion. The perspective of developing forest carbon absorption ...

  18. NutriPhone: vitamin B12 testing on your smartphone (Conference Presentation)

    Science.gov (United States)

    Lee, Seoho; O'Dell, Dakota; Hohenstein, Jessica; Colt, Susannah; Mehta, Saurabh; Erickson, David

    2016-03-01

    Vitamin B12 deficiency is the leading cause of cognitive decline in the elderly and is associated with increased risks of several acute and chronic conditions including anemia. The deficiency is prevalent among the world population, most of whom are unaware of their condition due to the lack of a simple diagnostics system. Recent advancements in the smartphone-enabled mobile health can help address this problem by making the deficiency tests more accessible. Previously, our group has demonstrated the NutriPhone, a smartphone platform for the accurate quantification of vitamin D levels. The NutriPhone technology comprises of a disposable test strip that performs a colorimetric reaction upon collecting a sample, a reusable accessory that interfaces with the smartphone camera, and a smartphone app that stores the algorithm for analyzing the test-strip reaction. In this work, we show that the NutriPhone can be expanded to measure vitamin B12 concentrations by developing a lateral flow assay for B12 that is compatible with our NutriPhone system. Our novel vitamin B12 assay incorporates blood sample processing and key reagent storage on-chip, which advances it into a sample-in-answer-out format that is suitable for point-of-care diagnostic applications. In order to enable the detection of pM levels of vitamin B12 levels, silver amplification of the initial signal is used within the total assay time of less than 15 minutes. We demonstrate the effectiveness of our NutriPhone system by deploying it in a resource-limited clinical setting in India where it is used to test tens of participants for vitamin B12 deficiency.

  19. Vitamin B12 deficiency evaluation and treatment in severe dry eye disease with neuropathic ocular pain.

    Science.gov (United States)

    Ozen, Serkan; Ozer, Murat Atabey; Akdemir, Mehmet Orçun

    2017-06-01

    This study aims to understand the effect of vitamin B12 deficiency on neuropathic ocular pain (NOP) and symptoms in patients with dry eye disease (DED). Patients with severe DED (without receiving topical artificial tears treatment) and ocular pain were enrolled (n = 90). Patients with severe DED and vitamin B12 deficiency (group 1, n = 45) received parenteral vitamin B12 supplement + topical treatment (artificial tears treatment + cyclosporine), and patients with severe DED and normal serum vitamin B12 level (group 2, n = 45) received only topical treatment (artificial tears treatment + cyclosporine). Patients were evaluated by the ocular surface disease index (OSDI) questionnaire, 3rd question (have you experienced painful or sore eyes during last week?) score of OSDI as a pain determiner and pain frequency measure), tear break up time (TBUT), and Schirmer's type 1 test. We compared the groups' OSDI, TBUT, and Schirmer's test recordings at the first visit and after 12 weeks retrospectively. The OSDI score, 3rd OSDI question score, TBUT, and Schirmer's test results improved after 12 weeks (p treatment. The mean score changes between the groups were not statistically significant; however, the decrease in the OSDI questionnaire score (-30.80 ±5.24) and 3rd OSDI question score (-2.82 ±0.53) were remarkable in group 1 (Table 2). The mean TBUT increase was +7.98 ±2.90 s and Schirmer's test result increase was +12.16 ±2.01 mm in group 1. The mean TBUT increase was +6.18 ±1.49 s and Schirmer's test result increase was +6.71 ±1.47 mm in group 2. These findings indicate that vitamin B12 deficiency is related with NOP. It may be important to consider measuring the serum vitamin B12 level in patients with severe DED presenting with resistant ocular pain despite taking topical treatment.

  20. Serum homocysteine, folate, vitamin B12 and total antioxidant status in vegetarian children.

    Science.gov (United States)

    Ambroszkiewicz, J; Klemarczyk, W; Chełchowska, M; Gajewska, J; Laskowska-Klita, T

    2006-01-01

    The results of several studies point to the positive role of vegetarian diets in reducing the risk of diabetes, some cancers and cardiovascular diseases. However, exclusion of animal products in vegetarian diets may affect the cobalamin status and cause an elevation of the plasma homocysteine level. The aim of this study was to assess the effect of vegetarian diets on serum concentrations of homocysteine, folate, vitamin B12 and total antioxidant status (TAS) in children. The study included 32 vegetarians (including 5 vegans), age 2-10 years. Dietary constituents were analyzed using a local nutritional programme. Serum homocysteine, folate and vitamin B12 were determined with fluorescence and chemiluminescence immunoassays. The concentration of TAS was measured by a colorimetric method. Average daily energy intake and the percentage of energy from protein, fat and carbohydrates in the diets of the studied children were just above or similar to the recommended amounts. It could be shown that vegetarian diets contain high concentrations of folate. In vegan diets it even exceeds the recommended dietary allowance. Mean daily intake of vitamin B12 in the studied diets was adequate but in vegans was below the recommended range. The serum concentrations of homocysteine, folate, vitamin B12 and TAS in vegetarian children remained within the physiological range. The presented data indicate that vegetarian children, contrary to adults, have enough vitamin B12 in their diet (excluding vegans) and normal serum concentrations of homocysteine, folate and vitamin B12. Therefore, in order to prevent deficiencies in the future, close monitoring of vegetarian children (especially on a vegan diet) is important to make sure that they receive adequate quantities of nutrients needed for healthy growth.

  1. A Computational Tale of Two Enzymes: Glycerol Dehydration With or Without B12.

    Science.gov (United States)

    Kovačević, Borislav; Barić, Danijela; Babic, Darko; Bilić, Luka; Hanževački, Marko; Sandala, Gregory M; Radom, Leo; Smith, David M

    2018-06-12

    We present a series of QM/MM calculations aimed at understanding the mechanism of the biological dehydration of glycerol. Strikingly and unusually, this process is catalyzed by two different radical enzymes, one of which is a coenzyme-B 12 - dependent enzyme and the other which is a coenzyme-B 12 - independent enzyme. We show that glycerol dehydration in the presence of the coenzyme-B 12 -dependent enzyme proceeds via a 1,2-OH shift, which benefits from a significant catalytic reduction in the barrier. In contrast, the same reaction in the presence of the coenzyme-B 12 -independent enzyme is unlikely to involve the 1,2-OH shift; instead, a strong preference for direct loss of water from a radical intermediate is indicated. We show that this preference and, ultimately the evolution of such enzymes, is strongly linked with the reactivities of the species responsible for abstracting a hydrogen atom from the substrate. It appears that the hydrogen re-abstraction step involving the product-related radical is fundamental to the mechanistic preference. The unconventional 1,2-OH shift seems to be required to generate a product-related radical of sufficient reactivity to cleave the relatively inactive C-H bond arising from the B 12 cofactor. In the absence of B 12 , it is the relatively weak S-H bond of a cysteine residue that must be homolyzed. Such a transformation is much less demanding and its inclusion apparently enables a simpler overall dehydration mechanism.

  2. Double tungsten coil atomic absorption spectrometer based on an acousto-optic tunable filter

    International Nuclear Information System (INIS)

    Jora, M.Z.; Nóbrega, J.A.; Rohwedder, J.J.R.; Pasquini, C.

    2015-01-01

    An atomic absorption spectrometer based on a quartz acousto-optic tunable filter (AOTF) monochromator operating in the 271–453 nm range, is described. The instrument was tailored to study the formation and evolution of electrothermal atomic cloud induced either by one or two tungsten coils. The spectrometer also includes a fast response programmable photomultiplier module for data acquisition, and a power supply capable of driving two parallel tungsten coils independently. The atomization cell herein described was manufactured in PTFE and presents a new design with reduced size. Synchronization between the instant of power delivering to start the atomization process and the detection was achieved, allowing for monitoring the atomization and thermal events synchronously and in real time. Absorption signals can be sampled at a rate of a few milliseconds, compatible with the fast phenomena that occur with electrothermal metallic atomizers. The instrument performance was preliminarily evaluated by monitoring the absorption of radiation of atomic clouds produced by standard solutions containing chromium or lead. Its quantitative performance was evaluated by using Cr aqueous solutions, resulting in detection limits as low as 0.24 μg L −1 , and a relative standard deviation of 3%. - Highlights: • The use of an Acousto-Optic Tunable Filter (AOTF) as monochromator element in WC AAS is presented for the first time. • The system includes the possibility of using one or two parallel coils. • We propose a new atomization cell design, manufactured on PTFE with reduced size. • The temperature of the coils and the atomic clouds of Pb and Cr were observed synchronously with high temporal resolution

  3. NLP model based thermoeconomic optimization of vapor compression–absorption cascaded refrigeration system

    International Nuclear Information System (INIS)

    Jain, Vaibhav; Sachdeva, Gulshan; Kachhwaha, S.S.

    2015-01-01

    Highlights: • It addresses the size and cost estimation of cascaded refrigeration system. • Cascaded system is a promising decarburizing and energy efficient technology. • Second law analysis is carried out with modified Gouy-Stodola equation. • The total annual cost of plant operation is optimized in present work. - Abstract: This paper addresses the size and cost estimation of vapor compression–absorption cascaded refrigeration system (VCACRS) for water chilling application taking R410a and water–LiBr as refrigerants in compression and absorption section respectively which can help the design engineers in manufacturing and experimenting on such kind of systems. The main limitation in the practical implementation of VCACRS is its size and cost which are optimized in the present work by implementing Direct Search Method in non-linear programming (NLP) mathematical model of VCACRS. The main objective of optimization is to minimize the total annual cost of system which comprises of costs of exergy input and capital costs in monetary units. The appropriate set of decision variables (temperature of evaporator, condenser, generator, absorber, cascade condenser, degree of overlap and effectiveness of solution heat exchanger) minimizes the total annual cost of VCACRS by 11.9% with 22.4% reduction in investment cost at the base case whereas the same is reduced by 7.5% with 11.7% reduction in investment cost with reduced rate of interest and increased life span and period of operation. Optimization results show that the more investment cost in later case is well compensated through the performance and operational cost of the system. In the present analysis, optimum cascade condensing temperature is a strong function of period of operation and capital recovery factor. The cascading of compression and absorption systems becomes attractive for lower rate of interest and increase life span and operational period

  4. [Measurement of atomic number of alkali vapor and pressure of buffer gas based on atomic absorption].

    Science.gov (United States)

    Zheng, Hui-jie; Quan, Wei; Liu, Xiang; Chen, Yao; Lu, Ji-xi

    2015-02-01

    High sensitivitymagnetic measurementscanbe achieved by utilizing atomic spinmanipulation in the spin-exchange-relaxation-free (SERF) regime, which uses an alkali cell as a sensing element. The atomic number density of the alkali vapor and the pressure of the buffer gasare among the most important parameters of the cell andrequire accurate measurement. A method has been proposed and developedto measure the atomic number density and the pressure based on absorption spectroscopy, by sweeping the absorption line and fittingthe experiment data with a Lorentzian profile to obtainboth parameters. Due to Doppler broadening and pressure broadening, which is mainly dominated by the temperature of the cell and the pressure of buffer gas respectively, this work demonstrates a simulation of the errorbetween the peaks of the Lorentzian profile and the Voigt profile caused by bothfactors. The results indicates that the Doppler broadening contribution is insignificant with an error less than 0.015% at 313-513 K for a 4He density of 2 amg, and an error of 0.1% in the presence of 0.6-5 amg at 393 K. We conclude that the Doppler broadening could be ignored under above conditions, and that the Lorentzianprofile is suitably applied to fit the absorption spectrumobtainingboth parameters simultaneously. In addition we discuss the resolution and the instability due to thelight source, wavelength and the temperature of the cell. We find that the cell temperature, whose uncertainty is two orders of magnitude larger than the instability of the light source and the wavelength, is one of the main factors which contributes to the error.

  5. Transcobalamin C776G genotype modifies the association between vitamin B12 and homocysteine in older hispanics

    Science.gov (United States)

    Background: A common polymorphism, C776G, in the plasma B12 transport protein transcobalamin (TC), encodes for either proline or arginine at codon 259. This polymorphism may affect the affinity of TC for B12 and subsequent delivery of B12 to tissues. Methods: TC genotype and its associations with i...

  6. Fisiopatologia da deficiência de vitamina B12 e seu diagnóstico laboratorial

    OpenAIRE

    Paniz,Clóvis; Grotto,Denise; Schmitt,Gabriela Cristina; Valentini,Juliana; Schott,Karen Lílian; Pomblum,Valdeci Juarez; Garcia,Solange Cristina

    2005-01-01

    INTRODUÇÃO: A vitamina B12 é hidrossolúvel, não-sintetizada pelo organismo humano, presente em alimentos de origem animal. Sua deficiência é muito freqüente entre idosos, vegetarianos e indivíduos que adotam baixa dieta protéica ou apresentam problemas de absorção gastrintestinal. FISIOPATOLOGIA: A deficiência de vitamina B12 leva a transtornos hematológicos, neurológicos e cardiovasculares, principalmente, por interferir no metabolismo da homocisteína (Hcy) e nas reações de metilação do orga...

  7. Biosynthesis of vitamin B12: concerning the origin of the methine protons of the corrin nucleus

    International Nuclear Information System (INIS)

    Scott, A.I.; Kajiwara, M.; Santander, P.J.

    1987-01-01

    13C NMR spectroscopy has been used to locate six deuterium atoms incorporated biosynthetically on the periphery of the corrin nucleus of vitamin B12 (cyanocobalamin) derived from cells of Propionibacterium shermanii grown in a medium containing 50% 2 H 2 O and 13 C-enriched delta-aminolevulinic acid. The implications of these results for the mechanism of vitamin B12 biosynthesis are discussed, and it is concluded that the same oxidation level of the intermediates is maintained throughout the biosynthetic pathway, from delta-aminolevulinic acid to corrin

  8. CA 15-3 predicting breast cancer relapse: beware of vitamin B12 deficiency.

    Science.gov (United States)

    Rassy, Elie El; Ghor, Maya Al; Kattan, Joseph

    2018-05-10

    A sustained increase of cancer antigen 15-3 serum levels was found in a 54-year-old woman treated 2 years ago for early stage breast cancer, without any evidence of cancer recurrence. The patient thereafter developed severe megaloblastic anemia secondary to vitamin B12 deficiency. Supplementation with B12 to reverse the anemia led to the normalization of the cancer antigen 15-3 serum levels. As such, with the limited understanding of molecular biology, the integrative approach of clinical history, physical examination, and diagnostic imaging remain pivotal in the management of cancer patients.

  9. Reversible Vitamin B12 Deficiency Presenting with Acute Dementia, Paraparesis, and Normal Hemoglobin

    Directory of Open Access Journals (Sweden)

    Hani Almoallim

    2016-01-01

    Full Text Available Vitamin B12 is essential for neurological function and its deficiency is associated with many neuropsychiatric disorders. We report the case of a previously healthy 53-year-old male patient presenting with delirium and multiple neurological findings. Complete blood analysis indicated megaloblastic anemia. All infectious causes were excluded owing to negative cultures (blood and urine. Tests for human immunodeficiency virus, syphilis, and toxoplasma were also negative. Metabolic workup showed severe vitamin B12 deficiency, decreased reticulocyte count, and increased direct bilirubin and lactate dehydrogenase. Intramuscular injection of cobalamin was started, and the patient showed significant improvement.

  10. Lessons to be learned: a case study approach. Vitamin B12 deficiency of nutritional origin.

    Science.gov (United States)

    Donaldson, D

    1997-10-01

    The case is presented of a 14 year old boy who developed severe anaemia at the onset of puberty caused by nutritional deficiency of vitamin B12 of about 10 years duration. The dietary intake comprised mainly chips, ice-cream, fruit and Coca-Cola--with small amounts of vitamin B12 from occasional slices of chicken meat. His denial of abnormal nutritional intake, supported by his mother, delayed confirmation of the correct diagnosis. However, the true situation was eventually confessed--and following implementation of a normal diet he rapidly improved clinically, the haemoglobin value rose to normal and he subsequently remained well.

  11. Density Transition Based Self-Focusing of cosh-Gaussian Laser Beam in Plasma with Linear Absorption

    International Nuclear Information System (INIS)

    Kant, Niti; Wani, Manzoor Ahmad

    2015-01-01

    Density transition based self-focusing of cosh-Gaussian laser beam in plasma with linear absorption has been studied. The field distribution in the plasma is expressed in terms of beam width parameter, decentered parameter, and linear absorption coefficient. The differential equation for the beam width parameter is solved by following Wentzel–Kramers–Brillouin (WKB) and paraxial approximation through parabolic wave equation approach. The behaviour of beam width parameter with dimensionless distance of propagation is studied at optimum values of plasma density, decentered parameter and with different absorption levels in the medium. The results reveal that these parameters can affect the self-focusing significantly. (paper)

  12. The effect of vitamin B12 supplementation in Nepalese infants on growth and development: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Strand, Tor A; Ulak, Manjeswori; Chandyo, Ram K; Kvestad, Ingrid; Hysing, Mari; Shrestha, Merina; Basnet, Sudha; Ranjitkar, Suman; Shrestha, Laxman; Shrestha, Prakash S

    2017-04-21

    Vitamin B 12 deficiency is one of the most common micronutrient deficiencies and is associated with poor cognitive development and growth. Vitamin B 12 is crucial for normal cell division and differentiation, and it is necessary for the development and myelination of the central nervous system. The aim of the present study is to measure the effect of daily supplementation of vitamin B 12 on the neurodevelopment and growth of young children in Nepal. We are conducting an individually randomized, double-blind, placebo-controlled trial with 600 marginally stunted children 6-11 months old (length for age less than -1 z-score). Children are randomized to receive a lipid-based paste containing vitamin B 12 or placebo daily for 12 months. The main outcomes are changes in growth (z-scores) and in neurodevelopment measured by the Bayley Scales of Infant and Toddler Development, Third Edition, from baseline until the end of the study. If vitamin B 12 supplementation benefits early child development and growth, this will have consequences for dietary recommendations for malnourished children worldwide. ClinicalTrials.gov Identifier: NCT02272842 . Registered on 21 October 2014. Universal Trial Number: U1111-1161-5187. Registered on 8 September 2014.

  13. Performance Evaluation of a Nanofluid-Based Direct Absorption Solar Collector with Parabolic Trough Concentrator

    Directory of Open Access Journals (Sweden)

    Guoying Xu

    2015-12-01

    Full Text Available Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the coating can lead to an increased manufacturing cost and unreliability for a solar collector operated at a higher temperature. Therefore, a novel nanofluid-based direct absorption solar collector (NDASC employing uncoated collector tubes has been proposed, and its operating characteristics for medium-temperature solar collection were theoretically and experimentally studied in this paper. CuO/oil nanofluid was prepared and used as working fluid of the NDASC. The heat-transfer mechanism of the NDASC with parabolic trough concentrator was theoretically evaluated and compared with a conventional indirect absorption solar collector (IASC. The theoretical analysis results suggested that the fluid’s temperature distribution in the NDASC was much more uniform than that in the IASC, and an enhanced collection efficiency could be achieved for the NDASC operated within a preferred working temperature range. To demonstrate the feasibility of the proposed NDASC, experimental performances of an NDASC and an IASC with the same parabolic trough concentrator were furthermore evaluated and comparatively discussed.

  14. Wideband RCS Reduction of Microstrip Array Antenna Based on Absorptive Frequency Selective Surface and Microstrip Resonators

    Directory of Open Access Journals (Sweden)

    Jingjing Xue

    2017-01-01

    Full Text Available An approach for wideband radar cross section (RCS reduction of a microstrip array antenna is presented and discussed. The scheme is based on the microstrip resonators and absorptive frequency selective surface (AFSS with a wideband absorptive property over the low band 1.9–7.5 GHz and a transmission characteristic at high frequency 11.05 GHz. The AFSS is designed to realize the out-of-band RCS reduction and preserve the radiation performance simultaneously, and it is placed above the antenna with the operating frequency of 11.05 GHz. Moreover, the microstrip resonators are loaded to obtain the in-band RCS reduction. As a result, a significant RCS reduction from 1.5 GHz to 13 GHz for both types of polarization has been accomplished. Compared with the reference antenna, the simulated results exhibit that the monostatic RCS of the proposed array antenna in x- and y-polarization can be reduced as much as 17.6 dB and 21.5 dB, respectively. And the measured results agree well with the simulated ones.

  15. Performance Evaluation of a Nanofluid-Based Direct Absorption Solar Collector with Parabolic Trough Concentrator

    Science.gov (United States)

    Xu, Guoying; Chen, Wei; Deng, Shiming; Zhang, Xiaosong; Zhao, Sainan

    2015-01-01

    Application of solar collectors for hot water supply, space heating, and cooling plays a significant role in reducing building energy consumption. For conventional solar collectors, solar radiation is absorbed by spectral selective coating on the collectors’ tube/plate wall. The poor durability of the coating can lead to an increased manufacturing cost and unreliability for a solar collector operated at a higher temperature. Therefore, a novel nanofluid-based direct absorption solar collector (NDASC) employing uncoated collector tubes has been proposed, and its operating characteristics for medium-temperature solar collection were theoretically and experimentally studied in this paper. CuO/oil nanofluid was prepared and used as working fluid of the NDASC. The heat-transfer mechanism of the NDASC with parabolic trough concentrator was theoretically evaluated and compared with a conventional indirect absorption solar collector (IASC). The theoretical analysis results suggested that the fluid’s temperature distribution in the NDASC was much more uniform than that in the IASC, and an enhanced collection efficiency could be achieved for the NDASC operated within a preferred working temperature range. To demonstrate the feasibility of the proposed NDASC, experimental performances of an NDASC and an IASC with the same parabolic trough concentrator were furthermore evaluated and comparatively discussed. PMID:28347112

  16. Homocisteína, folato e vitamina B12 em pacientes colombianos portadores de coronariopatia Homocysteine, folate and vitamin B12 in colombian patients with coronary disease

    Directory of Open Access Journals (Sweden)

    Gilberto Garcia

    2007-08-01

    Full Text Available OBJETIVO: Determinar a existência de associação entre os níveis plasmáticos de homocisteína, folato ou vitamina B12 e síndrome coronariana aguda em pacientes colombianos. MÉTODOS: Estudo caso-controle: foram 50 pacientes portadores de síndrome coronariana aguda e 50 pacientes ambulatoriais sem síndrome coronariana. Foram medidos os níveis de homocisteína, folato e vitamina B12 por meio de imunoensaio por quimioluminescência. Foram também medidos os níveis de colesterol e frações, triglicérides, uréia, creatinina, hemoglobina e hematócrito. RESULTADOS: As concentrações plasmáticas médias de homocisteína foram significativamente diferentes entre os casos (12,4 µmol/l ± 6,0 e os controles (9,7 µmol/l ± 2,4, p=0,01. Os níveis de ácido fólico dos casos foram menores que os dos controles (respectivamente 10,5 ng/ml ± 3,5 x 12,6 ng/ml ± 3,6; p=0,01. Foi observada relação inversa entre os níveis de folato e os de homocisteína. Não houve relação entre os níveis de vitamina B12 e os de homocisteína. Houve diferença significativa nos níveis de triglicérides entre os grupos caso e controle (respectivamente 136,91 ± 67,27 x 174,3 ± 77,6; p=0,01. A razão das chances para hiper-homocisteinemia na síndrome coronariana aguda foi de 4,45 (intervalo de confiança de 95%: 1,5 - 13,3. CONCLUSÃO: O presente estudo demonstrou associação significativa entre os níveis de homocisteína e síndrome coronariana aguda em pacientes colombianos semelhante à encontrada em populações européias e norte-americanas. Houve correlação negativa entre os níveis plasmáticos de homocisteína e os de folato. Não houve associação entre os níveis plasmáticos de homocisteína e os de vitamina B12.OBJECTIVE: To determine the occurrence of association between homocysteine, folate, or vitamin B12 plasma levels and acute coronary syndrome in Colombian patients. METHODS: Case control study: cases were 50 patients with acute

  17. Semi-empirical γ-ray peak efficiency determination including self-absorption correction based on numerical integration

    International Nuclear Information System (INIS)

    Noguchi, M.; Takeda, K.; Higuchi, H.

    1981-01-01

    A method of γ-ray efficiency determination for extended (plane or bulk) samples based on numerical integration of point source efficiency is studied. The proposed method is widely applicable to samples of various shapes and materials. The geometrical factor in the peak efficiency can easily be corrected for by simply changing the integration region, and γ-ray self-absorption is also corrected by the absorption coefficients for the sample matrix. (author)

  18. Mechanistic understanding of the effect of PPIs and acidic carbonated beverages on the oral absorption of itraconazole based on absorption modeling with appropriate in vitro data.

    Science.gov (United States)

    Fotaki, Nikoletta; Klein, Sandra

    2013-11-04

    Proton pump inhibitors (PPIs) are potent gastric acid suppressing agents and are among the most widely sold drugs in the world. However, even though these antisecretory agents are regarded as safe, they can alter the pharmacokinetics of coadministered drugs. Due to the suppression of gastric acid secretion, they can significantly alter the intragastric pH conditions and are thus likely to affect the bioavailability of coadministered drugs requiring an acidic gastric environment for dissolution and subsequent absorption. Among these drugs can be found itraconazole, a poorly soluble triazole-type antifungal compound. Based on observations reported in the literature, gastric pH alterations due to the coadministration of PPIs or acidic beverages can significantly decrease (PPI) or increase (e.g., Coca-Cola) the bioavailability of this compound. In the present work we estimated the fraction of itraconazole that can be absorbed (fabs) from Sporanox capsules or an itraconazole-HBenBCD complex formulation after oral administration with and without coadministration of a PPI or an acidic (carbonated) beverage. For this purpose, the sensitivity of the two formulations toward the impact of various gastric variations (pH, volume, and emptying rate) as they can result from such administration conditions was studied using solubility and dissolution experiments and a physiologically based absorption model. Simulating coadministration of the two formulations with a PPI resulted in a significant (∼ 10-fold) decrease in itraconazole fabs, indicating the pH to be essential for in vivo dissolution and subsequent absorption. The fabs of itraconazole after coadministration of an acidic beverage (Coca-Cola) was far lower than the fabs obtained for itraconazole alone and did not support the observations reported in the literature. These results clearly indicate that in contrast to PPIs, which seem to affect itraconazole bioavailability mainly via intragastric pH changes, coadministered

  19. Phylogenetic analysis of vitamin B12-related metabolism in Mycobacterium tuberculosis

    OpenAIRE

    Young, Douglas B.; Comas, I?aki; de Carvalho, Luiz P. S.

    2015-01-01

    Comparison of genome sequences from clinical isolates of Mycobacterium tuberculosis with phylogenetically-related pathogens Mycobacterium marinum, Mycobacterium kansasii, and Mycobacterium leprae reveals diversity amongst genes associated with vitamin B12-related metabolism. Diversity is generated by gene deletion events, differential acquisition of genes by horizontal transfer, and single nucleotide polymorphisms (SNPs) with predicted impact on protein function and transcriptional regulation...

  20. Vitamin B12 deficiency might be related to sarcopenia in older adults.

    Science.gov (United States)

    Bulut, Esra Ates; Soysal, Pinar; Aydin, Ali Ekrem; Dokuzlar, Ozge; Kocyigit, Suleyman Emre; Isik, Ahmet Turan

    2017-09-01

    Sarcopenia and dynapenia are related to repeated falls, mobility restriction, depression, frailty, increased mortality and morbidity. The aim of this study is to evaluate the relationship between vitamin B12 deficiency and sarcopenia in older adults. 403 patients, who attended to outpatient clinic and underwent comprehensive geriatric assessment, were included study. All cases' skeletal muscle mass (SMM), walking speed and hand grip strength were recorded by bioimpedance, 4meter walking test and hand dynamometer respectively. The diagnosis of sarcopenia was defined according to the criteria of the European Working Group on Sarcopenia in Older People. Sarcopenia was accepted low SMM with low handgrip strength or low physical performance. Dynapenia was defined as handgrip strength sarcopenia and dynapenia was 24.8% and 32.0%, respectively. In the patients with sarcopenia, mean age, osteoporosis and frailty were higher, and MMSE, and instrumental ADL scores were lower than the patients without sarcopenia (psarcopenia and dynapenia were 31.6% and 35.4%, respectively, in patients with vitamin B12 levels Sarcopenia, which results in lots of negative clinical outcomes in older adults, might be related to vitamin B12 deficiency. Therefore, these patients should be periodically examined for vitamin B12 deficiency due to the potential negative clinical outcomes such as sarcopenia in older adults. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Lifestyle and genetic determinants of folate and vitamin B12 levels in a general adult population

    DEFF Research Database (Denmark)

    Thuesen, Betina H; Husemoen, Lise Lotte N; Ovesen, Lars

    2009-01-01

    and the prevalence was lower with increasing age. Low serum folate was associated with smoking, low alcohol intake, high coffee intake, unhealthy diet, and the TT genotype of the methylenetetrahydrofolate reductase (MTHFR)-C677T polymorphism. The overall prevalence of low serum vitamin B12 (

  2. Serum folate, vitamin B-12 and cognitive function in middle and older age: The HAPIEE study.

    Science.gov (United States)

    Horvat, Pia; Gardiner, Julian; Kubinova, Ruzena; Pajak, Andrzej; Tamosiunas, Abdonas; Schöttker, Ben; Pikhart, Hynek; Peasey, Anne; Jansen, Eugene; Bobak, Martin

    2016-04-01

    Nutrient status of B vitamins, particularly folate and vitamin B-12, may be related to cognitive ageing but epidemiological evidence remains inconclusive. The aim of this study was to estimate the association of serum folate and vitamin B-12 concentrations with cognitive function in middle-aged and older adults from three Central and Eastern European populations. Men and women aged 45-69 at baseline participating in the Health, Alcohol and Psychosocial factors in Eastern Europe (HAPIEE) study were recruited in Krakow (Poland), Kaunas (Lithuania) and six urban centres in the Czech Republic. Tests of immediate and delayed recall, verbal fluency and letter search were administered at baseline and repeated in 2006-2008. Serum concentrations of biomarkers at baseline were measured in a sub-sample of participants. Associations of vitamin quartiles with baseline (n=4166) and follow-up (n=2739) cognitive domain-specific z-scores were estimated using multiple linear regression. After adjusting for confounders, folate was positively associated with letter search and vitamin B-12 with word recall in cross-sectional analyses. In prospective analyses, participants in the highest quartile of folate had higher verbal fluency (pcognitive domains in older Central and Eastern Europeans. These findings do not lend unequivocal support to potential importance of folate and vitamin B-12 status for cognitive function in older age. Long-term longitudinal studies and randomised trials are required before drawing conclusions on the role of these vitamins in cognitive decline. Copyright © 2016. Published by Elsevier Inc.

  3. Brief Report: Childhood Disintegrative Disorder as a Likely Manifestation of Vitamin B12 Deficiency

    Science.gov (United States)

    Malhotra, Savita; Subodh, B. N.; Parakh, Preeti; Lahariya, Sanjay

    2013-01-01

    Childhood disintegrative disorder is a rare disorder, characterized by regression of acquired skills after a period of normal development. The case of childhood disintegrative disorder presented here was found to have vitamin B12 deficiency and hyperhomocysteinemia on extensive evaluation to find a probable cause for regression. This case…

  4. Effects of divalent cations on vitamin B12 adsorption to brush borders of rat intestine

    International Nuclear Information System (INIS)

    Miyata, Satoru; Inada, Masami

    1976-01-01

    A brush border preparation from rat intestine was incubated with rat intrinsic factor-vitamin B 12 complex in 0.01M Tris-HCl buffer, pH 7.4. The 57 Co-B 12 uptake to brush borders was proportional to the amount of protein or to alkaline phosphatase activity in the preparations. The uptake increased with time of incubation. At 37 0 C, the uptake after incubation for 15 min. was 80-85% of that for one hr. The uptake at 4 0 C was approximately 70% of that at 37 0 C. There was no difference as a result of adding glucose to the incubation medium. The uptake was observed in the alkaline environment above pH 6.3. Maximum uptake occurred at pH 8.0. Brush borders washed with Krebs-Ringer bicarbonate buffer (pH 7.4) exhibited no difference in B 12 uptake, whether in the presence of absence of calcium ion. But brush borders washed with ethylenediaminetetraacetate exhibited no uptake when incubated in calcium-free medium. The uptake reached a maximum by addition of calcium ion at a concentration of 0.3 mM, and was not alter up to 10 mM. Addition of magnesium ion exhibited no uptake. Calcium-dependent B 12 uptake was markedly inhibited by manganese ion. Magnesium ion seemed to slightly inhibit the calcium-dependent uptake. (auth.)

  5. Expeditious synthesis of noble metal nanoparticles using Vitamin B12 under microwave irradiation

    Science.gov (United States)

    A greener synthesis protocol for noble nanometals is developed using vitamin B12 as a reducing and capping agent in conjunction with the use of microwaves. Successful assembly of nanoparticles or microparticles with varied shapes and sizes have been demonstrated. The synthesized ...

  6. Dual pathology as a result of spinal stenosis and vitamin B12 deficiency.

    Science.gov (United States)

    Patel, Mohammed Shakil; Rasul, Zurqa; Sell, Philip

    2011-12-01

    Vitamin B12 deficiency can confound the clinical assessment of patients presenting with features of spinal disorders. Speciality practice within spinal surgery may lead the clinician to a focus upon spinal explanations for symptoms and that belief may be reinforced by supporting imaging. In the presence of mainly sensory symptoms consideration and exclusion of non surgical causes needs to occur. This study aimed at identifying the prevalence of vitamin B12 deficiency; the presence of dual pathology on imaging performed; the implementation of replacement therapy and their subsequent clinical response as perceived by patients. This was performed through a retrospective review of patients presenting to specialist spine out-patient clinics over a 4-year period via access to pathology reports followed by a telephone survey. 457 patients were investigated of which 8.5% were vitamin B12 deficient. 70% of patients had repeat levels and 31% continued to be deficient. 26% of these patients were not placed on any supplemental therapy. 72% of patients on treatment had self perceived improved outcomes as compared with 55% not on treatment. 73% of patients underwent MRI/CT imaging. 59% of which had evidence of spinal stenosis. In older patients with sensory symptoms, the coexistence of B12 deficiency should be considered. Detection of deficiency with consequent treatment results in better global outcomes than no treatment. Unless the correct blood test is done, the pathology will remain undetected, and patients may continue with their primary symptoms despite high-risk spinal surgical procedures.

  7. Total serum homocysteine as an indicator of vitamin B12 and folate status

    International Nuclear Information System (INIS)

    Chu, R.C.; Hall, C.A.

    1988-01-01

    Presented is a modification of an assay for total serum homocysteine (Hcy) in which the Hcy plus radioactive adenosine is converted enzymatically to labeled S-adenosylhomocysteine (AdoHcy). The modifications included a commerical source for the AdoHcy hydrolase, adenosine labeled with either 14 C or 3 H, and separation of the AdoHcy by thin layer chromatography. The assay was sensitive to 25 pmol. Hcy levels in sera from 18 controls ranged from 6.9 to 12.1 mumol/L with a mean of 9.1 and a SD of 1.5 mumol/L. The total serum Hcy was increased in vitamin B12 and folate deficiency. The level was high in congenital defects of vitamin B12 metabolism, blocking the methylation of Hcy regardless of the serum vitamin B12 levels, but was normal in the absence of tissue deficiency even if the serum vitamin B12 levels were low. The procedure has been found practical in two years of use and requires only 0.1 mL of serum

  8. Coenzyme B12 model studies: Equilibrium constants for the pH ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 114; Issue 1. Coenzyme B12 model studies: Equilibrium constants for the H-dependent axial ligation of benzyl(aquo)cobaloxime by various N- and S-donor ligands. D Sudarshan Reddy N Ravi Kumar Reddy V Sridhar S Satyanarayana. Inorganic and Analytical ...

  9. 17 CFR 240.3b-12 - Definition of OTC derivatives dealer.

    Science.gov (United States)

    2010-04-01

    ... to options, forwards, futures, swap agreements, or collars involving currencies, interest or other... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Definition of OTC derivatives... Securities Exchange Act of 1934 Definitions § 240.3b-12 Definition of OTC derivatives dealer. The term OTC...

  10. [Vitamin B12-independent strains of Methylophaga marina isolated from Red Sea algae].

    Science.gov (United States)

    Li, Ts D; Doronina, N V; Ivanova, E G; Trotsenko, Iu A

    2007-01-01

    Two strains (KM3 and KM5) of halophilic methylobacteria isolated from Red Sea algae do not require vitamin B12 for growth and can use methanol, methylamine, dimethylamine, trimethylamine, dimethyl sulfide, and fructose as sources of carbon and energy. The cells of these strains are gram-negative motile monotrichous (strain KM3) or peritrichous (strain KM5) rods. The strains are strictly aerobic and require Na+ ions but not growth factors for growth. They are oxidase- and catalase-positive and reduce nitrates to nitrites. Both strains can grow in a temperature range of 4 to 37 degrees C (with optimal growth at 29-34 degrees C), at pH between 5.5 and 8.5 (with optimal growth at pH 7.5-8.0), and in a range of salt concentrations between 0.5 and 15% NaCl (with optimal growth at 5-9% NaCl). The phospholipids of these strains are dominated by phosphatidylethanolamine and phosphatidylglycerol and also include phosphatidylcholine, phosphatidylserine, and cardiolipin. The dominant fatty acids are C(16:1omega7c) and C(16:0). The major ubiquinone is Q8. The cells accumulate ectoin, glutamate, and sucrose as intracellular osmoprotectants. The strains implement the 2-keto-3-deoxy-6-phosphogluconate-dependent variant of the ribulose monophosphate pathway. The G+C content of the DNA is 44.4-44.7 mol %. Analysis of the 16S rRNA genes showed that both strains belong to Gammaproteobacteria and have a high degree of homology (99.4%) to Methylophaga marina ATCC 35842T . Based on the data of polyphasic taxonomy, strains KM3 and KM5 are identified as new strains M. marina KM3 (VKM B-2386) and M. marina KM5 (VKM B-2387). The ability of these strains to produce auxins (indole-3-acetic acid) suggests their metabolic association with marine algae.

  11. Engineering a vitamin B12 high-throughput screening system by riboswitch sensor in Sinorhizobium meliloti.

    Science.gov (United States)

    Cai, Yingying; Xia, Miaomiao; Dong, Huina; Qian, Yuan; Zhang, Tongcun; Zhu, Beiwei; Wu, Jinchuan; Zhang, Dawei

    2018-05-11

    As a very important coenzyme in the cell metabolism, Vitamin B 12 (cobalamin, VB 12 ) has been widely used in food and medicine fields. The complete biosynthesis of VB 12 requires approximately 30 genes, but overexpression of these genes did not result in expected increase of VB 12 production. High-yield VB 12 -producing strains are usually obtained by mutagenesis treatments, thus developing an efficient screening approach is urgently needed. By the help of engineered strains with varied capacities of VB 12 production, a riboswitch library was constructed and screened, and the btuB element from Salmonella typhimurium was identified as the best regulatory device. A flow cytometry high-throughput screening system was developed based on the btuB riboswitch with high efficiency to identify positive mutants. Mutation of Sinorhizobium meliloti (S. meliloti) was optimized using the novel mutation technique of atmospheric and room temperature plasma (ARTP). Finally, the mutant S. meliloti MC5-2 was obtained and considered as a candidate for industrial applications. After 7 d's cultivation on a rotary shaker at 30 °C, the VB 12 titer of S. meliloti MC5-2 reached 156 ± 4.2 mg/L, which was 21.9% higher than that of the wild type strain S. meliloti 320 (128 ± 3.2 mg/L). The genome of S. meliloti MC5-2 was sequenced, and gene mutations were identified and analyzed. To our knowledge, it is the first time that a riboswitch element was used in S. meliloti. The flow cytometry high-throughput screening system was successfully developed and a high-yield VB 12 producing strain was obtained. The identified and analyzed gene mutations gave useful information for developing high-yield strains by metabolic engineering. Overall, this work provides a useful high-throughput screening method for developing high VB 12 -yield strains.

  12. High prevalence of suboptimal vitamin B12 status in young adult women of South Asian and European ethnicity.

    Science.gov (United States)

    Quay, Teo A W; Schroder, Theresa H; Jeruszka-Bielak, Marta; Li, Wangyang; Devlin, Angela M; Barr, Susan I; Lamers, Yvonne

    2015-12-01

    Suboptimal vitamin B12 (B12) status has been associated with an increased risk of congenital anomalies, preterm birth, and childhood insulin resistance. South Asians - Canada's largest minority group - and women of reproductive age are vulnerable to B12 deficiency. This study aimed to assess the prevalence of and factors associated with B12 deficiency and suboptimal B12 status in a convenience sample of young adult women of South Asian and European descent in Metro Vancouver. We measured serum B12, holotranscobalamin, plasma methylmalonic acid, red blood cell and plasma folate, and hematologic parameters in 206 nonpregnant, healthy women aged 19-35 years. Categorization for B12 status adhered to serum B12 cutoffs for deficiency (women is higher than in the general Canadian population. In light of maternal and fetal health risks associated with B12 inadequacy in early-pregnancy, practitioners should consider monitoring B12 status before and during early pregnancy, especially in immigrants and women with low dietary B12 intakes including non-users of vitamin supplements.

  13. Low levels of vitamin B12 can persist in the early resettlement of refugees: symptoms, screening and monitoring.

    Science.gov (United States)

    Benson, Jill; Phillips, Christine; Kay, Margaret; Hanifi, Hoda; Giri, Gauri; Leahy, Catherine; Lorimer, Michelle

    2015-09-01

    Many refugees have vitamin B12 (B12) deficiency. It has been assumed that deficiency would be predictable from macrocytosis or symptoms, and borderline levels would improve after a period of resettlement in countries rich with animal-source foods. We explored B12 levels and symptoms soon after the refugees' arrival and 4-8 months after settlement in Australia. Newly arrived refugees aged >18 years (n = 136) were tested for vitamin B12 and haematological indices. They also completed a language-validated questionnaire, which they repeated 4-8 months after arrival. B12 levels were reassessed in patients with levels ≤240 pmol at baseline. We found that 21 participants (15%) had low levels of B12 
(≤150 pmol/L) and 65 (48%) had borderline B12 levels 
(151-240 pmol/L). There was no relationship between B12 level and mean corpuscular volume, ferritin or symptoms. Borderline B12 levels persisted in 64% of participants at follow-up and deficiency developed in 11%. B12 levels cannot be predicted from macrocytosis or symptoms, and may not 'self-correct' after resettlement. Health assessments for newly arrived refugees should include B12 measurement and those with borderline levels should be followed up.

  14. Treatment of depression: time to consider folic acid and vitamin B12.

    Science.gov (United States)

    Coppen, Alec; Bolander-Gouaille, Christina

    2005-01-01

    We review the findings in major depression of a low plasma and particularly red cell folate, but also of low vitamin B12 status. Both low folate and low vitamin B12 status have been found in studies of depressive patients, and an association between depression and low levels of the two vitamins is found in studies of the general population. Low plasma or serum folate has also been found in patients with recurrent mood disorders treated by lithium. A link between depression and low folate has similarly been found in patients with alcoholism. It is interesting to note that Hong Kong and Taiwan populations with traditional Chinese diets (rich in folate), including patients with major depression, have high serum folate concentrations. However, these countries have very low life time rates of major depression. Low folate levels are furthermore linked to a poor response to antidepressants, and treatment with folic acid is shown to improve response to antidepressants. A recent study also suggests that high vitamin B12 status may be associated with better treatment outcome. Folate and vitamin B12 are major determinants of one-carbon metabolism, in which S-adenosylmethionine (SAM) is formed. SAM donates methyl groups that are crucial for neurological function. Increased plasma homocysteine is a functional marker of both folate and vitamin B12 deficiency. Increased homocysteine levels are found in depressive patients. In a large population study from Norway increased plasma homocysteine was associated with increased risk of depression but not anxiety. There is now substantial evidence of a common decrease in serum/red blood cell folate, serum vitamin B12 and an increase in plasma homocysteine in depression. Furthermore, the MTHFR C677T polymorphism that impairs the homocysteine metabolism is shown to be overrepresented among depressive patients, which strengthens the association. On the basis of current data, we suggest that oral doses of both folic acid (800 microg daily

  15. Absorptive Capacity, Alliance Portfolios and Innovation Performance: an Analytical Model Based on Bibliographic Research

    Directory of Open Access Journals (Sweden)

    Teresia Diana Lewe van Aduard de Macedo-Soares

    2016-10-01

    Full Text Available The objective of this article is to present a model for analysing the role of absorptive capacity in the relationship between strategic alliance portfolios and innovation performance based on the results of bibliographic research on the subject published between 2000 and 2015. The research was carried out in three stages, involving both quantitative - bibliometric and bibliographic coupling - and qualitative content analyses.  AP management capabilities were found to have a fundamental moderating role in the AP–IP relationship, and amongst these capabilities AC was highlighted by several authors. However, its role was found to vary according to AP characteristics, notably AP diversity – functional, geographic and institutional, but also centrality, size, stability and volume of resources, alliance and partner types as well as country type: emerging versus developed economies. This research formed the basis for the development of the model and the formulation of some propositions that focused on emerging countries.

  16. Generation of ultra-wide and flat optical frequency comb based on electro absorption modulator

    Science.gov (United States)

    Ujjwal; Thangaraj, Jaisingh

    2018-05-01

    A novel technique is proposed for the generation of ultra-wide and flat optical frequency comb (OFC) based on serially cascading three stages of electro absorption modulators (EAMs) through sinusoidal radio frequency (RF) signals by setting frequencies at f GHz, f/2 GHz and f/4 GHz. Here, the first stage acts as subcarrier generator, the second stage acts as subcarrier doubler, and the third stage acts as subcarrier quadrupler. In addition, a higher number of subcarriers can easily be generated by adjusting the driving sinusoidal RF signal. In this paper, cascading three stages of EAMs driven by 50 GHz, 25 GHz and 12.5 GHz clock sources, we obtain 272 subcarriers with spacing of 2.5 GHz and power deviation within 1 dB. Theoretical analysis of serially cascaded EAMs for subcarrier generation is also investigated. Principal analysis and simulation of this technique are demonstrated.

  17. Sub-parts-per-quadrillion-level graphite furnace atomic absorption spectrophotometry based on laser wave mixing.

    Science.gov (United States)

    Mickadeit, Fritz K; Berniolles, Sandrine; Kemp, Helen R; Tong, William G

    2004-03-15

    Nonlinear laser wave mixing in a common graphite furnace atomizer is presented as a zeptomole-level, sub-Doppler, high-resolution atomic absorption spectrophotometric method. A nonplanar three-dimensional wave-mixing optical setup is used to generate the signal beam in its own space. Signal collection is efficient and convenient using a template-based optical alignment. The graphite furnace atomizer offers advantages including fast and convenient introduction of solid, liquid, or gas analytes, clean atomization environment, and minimum background noise. Taking advantage of the unique features of the wave-mixing optical method and those of the graphite furnace atomizer, one can obtain both excellent spectral resolution and detection sensitivity. A preliminary concentration detection limit of 0.07 parts-per-quadrillion and a preliminary mass detection limit of 0.7 ag or 8 zmol are determined for rubidium using a compact laser diode as the excitation source.

  18. Natural gas pipeline leak detector based on NIR diode laser absorption spectroscopy.

    Science.gov (United States)

    Gao, Xiaoming; Fan, Hong; Huang, Teng; Wang, Xia; Bao, Jian; Li, Xiaoyun; Huang, Wei; Zhang, Weijun

    2006-09-01

    The paper reports on the development of an integrated natural gas pipeline leak detector based on diode laser absorption spectroscopy. The detector transmits a 1.653 microm DFB diode laser with 10 mW and detects a fraction of the backscatter reflected from the topographic targets. To eliminate the effect of topographic scatter targets, a ratio detection technique was used. Wavelength modulation and harmonic detection were used to improve the detection sensitivity. The experimental detection limit is 50 ppmm, remote detection for a distance up to 20 m away topographic scatter target is demonstrated. Using a known simulative leak pipe, minimum detectable pipe leak flux is less than 10 ml/min.

  19. Energy and Exergy Based Optimization of Licl-Water Absorption Cooling System

    Directory of Open Access Journals (Sweden)

    Bhargav Pandya

    2017-06-01

    Full Text Available This study presents thermodynamic analysis and optimization of single effect LiCl-H2O absorption cooling system. Thermodynamic models are employed in engineering equation solver to compute the optimum performance parameters. In this study, cut off temperature to operate system has been obtained at various operating temperatures. Analysis depicts that on 3.59 % rise in evaporator temperature, the required cut-off temperature decreased by 12.51%. By realistic comparison between thermodynamic first and second law analysis, optimum generator temperature relative to energy and exergy based prospective has been evaluated. It is found that optimum generator temperature is strong function of evaporator and condenser temperature. Thus, it is feasible to find out optimum generator temperature for various combinations of evaporator and condenser temperatures. Contour plots of optimum generator temperature for several combinations of condenser and absorber temperatures have been also depicted.

  20. Comparative genomic analyses of nickel, cobalt and vitamin B12 utilization

    Directory of Open Access Journals (Sweden)

    Gelfand Mikhail S

    2009-02-01

    Full Text Available Abstract Background Nickel (Ni and cobalt (Co are trace elements required for a variety of biological processes. Ni is directly coordinated by proteins, whereas Co is mainly used as a component of vitamin B12. Although a number of Ni and Co-dependent enzymes have been characterized, systematic evolutionary analyses of utilization of these metals are limited. Results We carried out comparative genomic analyses to examine occurrence and evolutionary dynamics of the use of Ni and Co at the level of (i transport systems, and (ii metalloproteomes. Our data show that both metals are widely used in bacteria and archaea. Cbi/NikMNQO is the most common prokaryotic Ni/Co transporter, while Ni-dependent urease and Ni-Fe hydrogenase, and B12-dependent methionine synthase (MetH, ribonucleotide reductase and methylmalonyl-CoA mutase are the most widespread metalloproteins for Ni and Co, respectively. Occurrence of other metalloenzymes showed a mosaic distribution and a new B12-dependent protein family was predicted. Deltaproteobacteria and Methanosarcina generally have larger Ni- and Co-dependent proteomes. On the other hand, utilization of these two metals is limited in eukaryotes, and very few of these organisms utilize both of them. The Ni-utilizing eukaryotes are mostly fungi (except saccharomycotina and plants, whereas most B12-utilizing organisms are animals. The NiCoT transporter family is the most widespread eukaryotic Ni transporter, and eukaryotic urease and MetH are the most common Ni- and B12-dependent enzymes, respectively. Finally, investigation of environmental and other conditions and identity of organisms that show dependence on Ni or Co revealed that host-associated organisms (particularly obligate intracellular parasites and endosymbionts have a tendency for loss of Ni/Co utilization. Conclusion Our data provide information on the evolutionary dynamics of Ni and Co utilization and highlight widespread use of these metals in the three

  1. Changes in water absorptivity of slag based cement mortars exposed to sulphur-oxidising A. thiooxidans bacteria

    Science.gov (United States)

    Estokova, A.; Smolakova, M.; Luptakova, A.; Strigac, J.

    2017-10-01

    Water absorptivity is heavily influenced by the volume and connectivity of pores in the pore network of cement composites and has been used as an important parameter for quantifying their durability. To improve the durability and permeability of mortars, various mineral admixtures such as furnace slag, silica fume or fly ash are added into the mortar and concrete mixtures. These admixtures provide numerous important advantages such as corrosion control, improvement of mechanical and physical properties and better workability. This study investigated the changes in absorptivity of cement mortars with different amounts of mineral admixture, represented by granulated blast furnace slag, under aggressive bacterial influence. The water absorptivity of mortars specimens exposed to sulphur-oxidising bacteria A. thiooxidans for the period of 3 and 6 months has changed due to bio-corrosion-based degradation process. The differences in water absorptivity in dependence on the mortars composition have been observed.

  2. Site- and phase-selective x-ray absorption spectroscopy based on phase-retrieval calculation

    International Nuclear Information System (INIS)

    Kawaguchi, Tomoya; Fukuda, Katsutoshi; Matsubara, Eiichiro

    2017-01-01

    Understanding the chemical state of a particular element with multiple crystallographic sites and/or phases is essential to unlocking the origin of material properties. To this end, resonant x-ray diffraction spectroscopy (RXDS) achieved through a combination of x-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) techniques can allow for the measurement of diffraction anomalous fine structure (DAFS). This is expected to provide a peerless tool for electronic/local structural analyses of materials with complicated structures thanks to its capability to extract spectroscopic information about a given element at each crystallographic site and/or phase. At present, one of the major challenges for the practical application of RXDS is the rigorous determination of resonant terms from observed DAFS, as this requires somehow determining the phase change in the elastic scattering around the absorption edge from the scattering intensity. This is widely known in the field of XRD as the phase problem. The present review describes the basics of this problem, including the relevant background and theory for DAFS and a guide to a newly-developed phase-retrieval method based on the logarithmic dispersion relation that makes it possible to analyze DAFS without suffering from the intrinsic ambiguities of conventional iterative-fitting. Several matters relating to data collection and correction of RXDS are also covered, with a final emphasis on the great potential of powder-sample-based RXDS (P-RXDS) to be used in various applications relevant to practical materials, including antisite-defect-type electrode materials for lithium-ion batteries. (topical review)

  3. Combined tunable diode laser absorption spectroscopy and monochromatic radiation thermometry in ammonium dinitramide-based thruster

    Science.gov (United States)

    Zeng, Hui; Ou, Dongbin; Chen, Lianzhong; Li, Fei; Yu, Xilong

    2018-02-01

    Nonintrusive temperature measurements for a real ammonium dinitramide (ADN)-based thruster by using tunable diode laser absorption spectroscopy and monochromatic radiation thermometry are proposed. The ADN-based thruster represents a promising future space propulsion employing green, nontoxic propellant. Temperature measurements in the chamber enable quantitative thermal analysis for the thruster, providing access to evaluate thermal properties of the thruster and optimize thruster design. A laser-based sensor measures temperature of combustion gas in the chamber, while a monochromatic thermometry system based on thermal radiation is utilized to monitor inner wall temperature in the chamber. Additional temperature measurements of the outer wall temperature are conducted on the injector, catalyst bed, and combustion chamber of the thruster by using thermocouple, respectively. An experimental ADN thruster is redesigned with optimizing catalyst bed length of 14 mm and steady-state firing tests are conducted under various feed pressures over the range from 5 to 12 bar at a typical ignition temperature of 200°C. A threshold of feed pressure higher than 8 bar is required for the thruster's normal operation and upstream movement of the heat release zone is revealed in the combustion chamber out of temperature evolution in the chamber.

  4. Cone-beam x-ray luminescence computed tomography based on x-ray absorption dosage

    Science.gov (United States)

    Liu, Tianshuai; Rong, Junyan; Gao, Peng; Zhang, Wenli; Liu, Wenlei; Zhang, Yuanke; Lu, Hongbing

    2018-02-01

    With the advances of x-ray excitable nanophosphors, x-ray luminescence computed tomography (XLCT) has become a promising hybrid imaging modality. In particular, a cone-beam XLCT (CB-XLCT) system has demonstrated its potential in in vivo imaging with the advantage of fast imaging speed over other XLCT systems. Currently, the imaging models of most XLCT systems assume that nanophosphors emit light based on the intensity distribution of x-ray within the object, not completely reflecting the nature of the x-ray excitation process. To improve the imaging quality of CB-XLCT, an imaging model that adopts an excitation model of nanophosphors based on x-ray absorption dosage is proposed in this study. To solve the ill-posed inverse problem, a reconstruction algorithm that combines the adaptive Tikhonov regularization method with the imaging model is implemented for CB-XLCT reconstruction. Numerical simulations and phantom experiments indicate that compared with the traditional forward model based on x-ray intensity, the proposed dose-based model could improve the image quality of CB-XLCT significantly in terms of target shape, localization accuracy, and image contrast. In addition, the proposed model behaves better in distinguishing closer targets, demonstrating its advantage in improving spatial resolution.

  5. Functional identification in Lactobacillus reuteri of a PocR-like transcription factor regulating glycerol utilization and vitamin B12 synthesis.

    NARCIS (Netherlands)

    Santos, F.; Spinler, J.K.; Saulnier, D.M.; Molenaar, D.; Teusink, B.; de Vos, W.M.; Versalovic, J.; Hugenholtz, J.

    2011-01-01

    BACKGROUND: Lactobacillus reuteri harbors the genes responsible for glycerol utilization and vitamin B12 synthesis within a genetic island phylogenetically related to gamma-Proteobacteria. Within this island, resides a gene (lreu_1750) that based on its genomic context has been suggested to encode

  6. Functional identification in Lactobacillus reuteri of a PocR-like transcription factor regulating glycerol utilization and vitamin B12 synthesis

    NARCIS (Netherlands)

    Santos, dos F.; Molenaar, D.; Teusink, B.; Vos, de W.M.

    2011-01-01

    BACKGROUND: Lactobacillus reuteri harbors the genes responsible for glycerol utilization and vitamin B12 synthesis within a genetic island phylogenetically related to gamma-Proteobacteria. Within this island, resides a gene (lreu_1750) that based on its genomic context has been suggested to encode

  7. A blue corrinoid from partial degradation of vitamin B12 in aqueous bicarbonate: spectra, structure, and interaction with proteins of B12 transport.

    Science.gov (United States)

    Fedosov, Sergey N; Ruetz, Markus; Gruber, Karl; Fedosova, Natalya U; Kräutler, Bernhard

    2011-09-20

    Cobalamin (Cbl) is a complex cofactor produced only by bacteria but used by all animals and humans. Cyanocobalamin (vitamin B(12), CNCbl) is one commonly isolated form of cobalamin. B(12) belongs to a large group of corrinoids, which are characterized by a distinct red color conferred by the system of conjugated double bonds of the corrin ring retaining a Co(III) ion. A unique blue Cbl derivative was produced by hydrolysis of CNCbl in a weakly alkaline aqueous solution of bicarbonate. This corrinoid was purified and isolated as dark blue crystals. Its spectroscopic analysis and X-ray crystallography revealed B-ring opening with formation of 7,8-seco-cyanocobalamin (7,8-sCNCbl). The unprecedented structural change was caused by cleavage of the peripheral C-C bond between saturated carbons 7 and 8 of the corrin macrocycle accompanied by formation of a C═C bond at C7 and a carbonyl group at C8. Additionally, the C-amide was hydrolyzed to a carboxylic acid. The extended conjugation of the π-system caused a considerable red shift of the absorbance spectrum. Formation and degradation of 7,8-sCNCbl were analyzed qualitatively. Its interaction with the proteins of mammalian Cbl transport revealed both a slow binding kinetics and a low overall affinity. The binding data were compared to those of other monocarboxylic derivatives and agreed with the earlier proposed scheme for two-step ligand recognition. The obtained results are consistent with the structural models of 7,8-sCNCbl and the transport proteins intrinsic factor and transcobalamin. Potential applications of the novel derivative for drug conjugation are discussed. © 2011 American Chemical Society

  8. High circulating folate and vitamin B-12 concentrations in women during pregnancy are associated with increased prevalence of atopic dermatitis in their offspring.

    Science.gov (United States)

    Kiefte-de Jong, Jessica C; Timmermans, Sarah; Jaddoe, Vincent W V; Hofman, Albert; Tiemeier, Henning; Steegers, Eric A; de Jongste, Johan C; Moll, Henriette A

    2012-04-01

    Recent studies suggest that in utero exposure of methyl donors influences programming of the fetal immune system in favor of development of allergic disease. The aim of this study was to assess whether the MTHFR C677T polymorphism, folic acid supplementation, and circulating folate and vitamin B-12 concentrations during pregnancy were associated with wheezing, shortness of breath, and atopic dermatitis in offspring. The study was a population-based birth cohort from fetal life until 48 mo (n = 8742). The use of folic acid supplementation during pregnancy was assessed by questionnaire. Plasma folate and serum vitamin B-12 concentrations and the MTHFR C677T polymorphism were available from blood collected in early pregnancy. Atopic dermatitis, wheezing, and shortness of breath in the offspring were assessed by parental-derived questionnaires at 12, 24, 36, and 48 mo. Maternal folate >16.2 nmol/L and vitamin B-12 >178 pmol/L were positively associated with the development of atopic dermatitis [adjusted OR: 1.18 (95% CI: 1.05-1.33) and adjusted OR: 1.30 (95% CI: 1.06-1.60) for the highest quartiles of folate and vitamin B-12 concentrations, respectively] but not with wheezing and shortness of breath. Maternal MTHFR C677T polymorphism and folic acid supplementation were not associated with wheezing, shortness of breath, and atopic dermatitis. No interactions were found by age, family history of atopy, folic acid supplementation, MTHFR C677T polymorphism, or maternal smoking (P-interaction > 0.10). High folate and vitamin B-12 levels during pregnancy are associated with increased prevalence of atopic dermatitis in the offspring. Potential risks of high folate and vitamin B-12 concentrations on allergic outcomes should be evaluated when discussing mandatory fortification programs.

  9. Assessment of transpulmonary absorption of ethanol from alcohol-based hand rub.

    Science.gov (United States)

    Hautemanière, Alexis; Ahmed-Lecheheb, Djihane; Cunat, Lisiane; Hartemann, Philippe

    2013-03-01

    Alcohol-based hand rubs (ABHRs) have been associated with a reduction of nosocomial infections. Despite the worldwide introduction of these products in health care settings, the aim of this study was to assess the transpulmonary absorption of ethanol contains in ABHRs used by health care workers (HCWs) in real conditions of work shift. Twenty-six HCWs of Nancy University Hospital were included. Research consisted in monitoring participants during 4 hours of work shift to assess their exposure to ethanol. The measurement of ethanol vapors in exhaled breath was performed using a class B ethylometer (Alco-Sensor FST). Ethanol concentration in inhaled breath was measured using Gilian pump LFS-113. Concentration of ethanol, acetaldehyde, and acetate in blood and urine samples were determined using gas chromatography with flame ionization detector. Participants were 12% male and 88% female. The mean age was 40 ± 8 years. None of the employees included in the study presented any traces of ethanol or its metabolites in the blood or urine. Ethanol (0.08 ± 0.07 mg/L) was detected in the breath of 10 HCWs at 1 to 2 minutes postexposure. The mean concentration of ethanol in the inhaled air was 46.2 mg/m. Absorption of ethanol vapor from ABHRs among HCWs during their care activities was not detected. Quantification of ethanol fumes inhaled during 4 hours of work shift was below the regulatory limitations of exposure to ethanol. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  10. Severe vitamin B12 deficiency in an exclusively breastfed 5-month-old Italian infant born to a mother receiving multivitamin supplementation during pregnancy

    Directory of Open Access Journals (Sweden)

    Guez Sophie

    2012-06-01

    Full Text Available Abstract Background In infants, vitamin B12 deficiency may be due to an inborn error of absorption and metabolism, or nutritional problems. Case presentation An exclusively breastfed 5-month-old Italian male infant, who was born after a normal full-term pregnancy to a vegan mother who was apparently daily treated with a multivitamin oral preparation during the second and third trimester, was hospitalised because of poor weight gain, feeding difficulties, severe pallor, muscle hypotonia and somnolence. Upon admission, his weight, length and head circumference were below the third percentile, he had an enlarged liver and spleen, and showed a significant delay in developmental milestones and communicative reactions. He had a hemoglobin level of 4.7 g/dL with an MCV of 84.2 fL, a white blood cell count of 4,680/mm3, and a platelet count of 45,000/mm3. His serum vitamin B12 level was 57 pg/mL (normal value 180–500 pg/mL and serum folate level 12.8 ng/mL (normal value >3 ng/mL. The results of metabolic examinations excluded a cobalamin C disorder, whereas nutritional screening showed a serum iron concentration of 9 μg/dL and serum ferritin of 4 ng/mL. Magnetic resonance imaging of the brain showed mild dilatation of the lateral ventricles with diffuse delayed myelination. The child was diagnosed as having vitamin B12 and iron deficiency due to nutritional inadequacy and was immediately treated with packed red blood cells, intramuscular vitamin B12 injections, and iron supplementation. A few days after the start of therapy, his hemoglobin levels and other hematological parameters rapidly improved, and a clinical improvement was observed within few weeks. There was an increase in his achievement of developmental milestones, but his development was still retarded seven months after the start of therapy. Conclusion This case underlines the importance of adequately controlling maternal vitamin B12 intake during pregnancy by means of

  11. Evaluation of ionic liquids as absorbents for ammonia absorption refrigeration cycles using COSMO-based process simulations

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, E.; Ferro, V.R., E-mail: victor.ferro@uam.es; Riva, J. de; Moreno, D.; Palomar, J.

    2014-06-01

    Highlights: • NH{sub 3}–IL absorption cycles are modeled by COSMO-based Aspen simulations. • Proposed a priori computational approach is validated using experimental data. • Cycle performance was analyzed for conventional and task-specific ILs. • IL solvents with high NH{sub 3} absorption capacity improve the cycle performance. • Using IL mixtures is revealed as promising alternative in NH{sub 3} absorption applications. - Abstract: COSMO-based process simulations with Aspen Plus/Aspen HYSYS are used, for the first time, to a priori estimate the thermodynamic performance of ammonia absorption refrigeration cycles using ionic liquids as absorbents. This allows not only broadening the criteria set used to select/design ionic liquids with optimized properties to be used in that role, but also evaluating innovative strategies to improve the cycle’s performances. COSMO-RS method provides the information required for both creating the ionic liquid non-database components and specifying the COSMOSAC property model to perform Aspen Plus calculations. The computational procedure used here gives at the same time reasonable good property predictions of the vapor (refrigerant) and the condensed (ammonia + ionic liquid) phases as well as physically consistent estimations of the cycle’s performance under different conditions. Current results agree with those previously reported in the literature for several ionic liquid-based systems taken for comparison. In addition, task-specific ionic liquids, with improved properties for ammonia absorption, and also binary ionic liquid mixtures are considered in the analysis. It is obtained that ionic liquids showing higher ammonia absorption capacity among the considered absorbents simultaneously provide the best cycle’s performances. The cycle performances vary in relatively wide intervals depending on the ammonia concentration in the (refrigerant + absorbent) solutions. This behavior is strongly modulated by the ammonia

  12. Evaluation of ionic liquids as absorbents for ammonia absorption refrigeration cycles using COSMO-based process simulations

    International Nuclear Information System (INIS)

    Ruiz, E.; Ferro, V.R.; Riva, J. de; Moreno, D.; Palomar, J.

    2014-01-01

    Highlights: • NH 3 –IL absorption cycles are modeled by COSMO-based Aspen simulations. • Proposed a priori computational approach is validated using experimental data. • Cycle performance was analyzed for conventional and task-specific ILs. • IL solvents with high NH 3 absorption capacity improve the cycle performance. • Using IL mixtures is revealed as promising alternative in NH 3 absorption applications. - Abstract: COSMO-based process simulations with Aspen Plus/Aspen HYSYS are used, for the first time, to a priori estimate the thermodynamic performance of ammonia absorption refrigeration cycles using ionic liquids as absorbents. This allows not only broadening the criteria set used to select/design ionic liquids with optimized properties to be used in that role, but also evaluating innovative strategies to improve the cycle’s performances. COSMO-RS method provides the information required for both creating the ionic liquid non-database components and specifying the COSMOSAC property model to perform Aspen Plus calculations. The computational procedure used here gives at the same time reasonable good property predictions of the vapor (refrigerant) and the condensed (ammonia + ionic liquid) phases as well as physically consistent estimations of the cycle’s performance under different conditions. Current results agree with those previously reported in the literature for several ionic liquid-based systems taken for comparison. In addition, task-specific ionic liquids, with improved properties for ammonia absorption, and also binary ionic liquid mixtures are considered in the analysis. It is obtained that ionic liquids showing higher ammonia absorption capacity among the considered absorbents simultaneously provide the best cycle’s performances. The cycle performances vary in relatively wide intervals depending on the ammonia concentration in the (refrigerant + absorbent) solutions. This behavior is strongly modulated by the ammonia absorption

  13. Mechanistic understanding of time-dependent oral absorption based on gastric motor activity in humans.

    Science.gov (United States)

    Higaki, Kazutaka; Choe, Sally Y; Löbenberg, Raimar; Welage, Lynda S; Amidon, Gordon L

    2008-09-01

    The relationship of gastric motor activity and gastric emptying of 0.7 mm caffeine pellets with their absorption was investigated in the fed state in healthy human subjects by simultaneous monitoring of antral motility and plasma concentrations. A kinetic model for gastric emptying-dependent absorption yielded multiple phases of gastric emptying and rate constants (k(g)) with large inter-individual differences and large variability in onset of gastric emptying (50-175 min). The model suggests that 50% of the dose is emptied in 1-2h and over 90% emptied by 3.5h following dosing, in all subjects. The maximum values of k(g) (k(g)(max)) were much greater than those reported for emptying of liquids in the fasted state and were comparable to k(g) values in the late Phase II/III of the migrating motor complex (MMC). The model described the observed irregular absorption rate-time and plasma concentration-time profiles adequately but not in detail. The model was more successful at simulating double-peak phenomena in absorption rate profiles and onset of caffeine absorption. The results suggest that gastric emptying regulates drug absorption of small particles in the fed state. Further, estimates of k(a) derived using the time-dependent absorption model were closer to the intrinsic absorption rate constant for caffeine.

  14. Vitamina B12, Acido Fólico y Función Mental en Adultos Mayores

    OpenAIRE

    Meertens-R, Lesbia; Solano-R, Liseti

    2005-01-01

    Los adultos mayores constituyen un grupo de población vulnerable a cuadros de deficiencias de nutrientes específicos como la vitamina B12 y el ácido fólico, íntimamente ligados al deterioro de las funciones mentales, en especial, del área cognitiva. El objetivo de este estudio fue determinar indicadores del estado de vitamina B12 y ácido fólico y asociarlos a la evaluación de la función mental de 53 adultos mayores de 60 años de edad, residenciados en un hogar geriátrico. Se evaluó consumo di...

  15. Radioisotope dilution technique for determination of vitamin B12 in foods

    International Nuclear Information System (INIS)

    Casey, P.J.; Speckman, K.R.; Ebert, F.J.; Hobbs, W.E.

    1982-01-01

    A radioisotope dilution (RID) method for the determination of vitamin B 12 is presented. The method combines a standard extraction procedure (AOAC 43.108, 12th ed.) with a commercially available RID assay kit. The method was evaluated on a wide range of fortified and unfortified food products. Recovery studies on both groups yielded average recoveries of 98.1 and 95.8%, respectively. Reproducibility data generated from replicate analysis on both groups gave a relative standard deviation of 6.9% for the fortified group and 9.2% for the unfortified group. For the samples studied, the mean vitamin B 12 content determined by the RID method was 8.01 μ/100 g vs a mean of 7.54 μg/100 g by the AOAC microbiological method; the correlation coefficient was r = 0.983

  16. An evaluation of commercial radioisotope methods for the determination of folate and vitamin B12

    International Nuclear Information System (INIS)

    Dawson, D.W.

    1980-01-01

    Five commercial kits for the determination of folate and six kits for the determination of vitamin B 12 were investigated. Their performance has been compared with microbiological methods for the two vitamins and with a non-commercial radioisotopic method for B 12 . The results show the importance of the determination of the reference range for an individual laboratory for each method. The precision of the kits varied appreciably, as did their performance using specimens from patients with different haematological disorders. In particular, certain kits failed to detect all patients with pernicious anaemia. The relative accuracy of the kits was assessed. Various factors which should be taken into account in the final selection of a satisfactory kit are discussed. (author)

  17. Phylogenetic analysis of vitamin B12-related metabolism in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Douglas B. Young

    2015-03-01

    Full Text Available Comparison of genome sequences from clinical isolates of Mycobacterium tuberculosis with phylogenetically-related pathogens Mycobacterium marinum, Mycobacterium kansasii and Mycobacterium leprae reveals diversity amongst genes associated with vitamin B12-related metabolism. Diversity is generated by gene deletion events, differential acquisition of genes by horizontal transfer, and single nucleotide polymorphisms with predicted impact on protein function and transcriptional regulation. Differences in the B12 synthesis pathway, methionine biosynthesis, fatty acid catabolism, and DNA repair and replication are consistent with adaptations to different environmental niches and pathogenic lifestyles. While there is no evidence of further gene acquisition during expansion of the M. tuberculosis complex, the emergence of other forms of genetic diversity provides insights into continuing host-pathogen co-evolution and has the potential to identify novel targets for disease intervention.

  18. Synthesis and crystal structure of Pb(Bipy)(DMFA)B12H12

    International Nuclear Information System (INIS)

    Lagun, V.L.; Solntsev, K.A.; Katser, S.B.; Orlova, A.M.; Kuznetsov, N.T.

    1994-01-01

    Lead complex with B 12 H 12 2- anion and neutral ligands -2,2' -bipyridine (Bipy) and dimethylformamide (DMFA) has been prepared by Pb(Bipy) B 12 H 12 recrystallization from mixed solvent DMFA - benzene (1:1). The complex prepared has been studied by the methods of IR spectroscopy, element and X-ray diffraction analyses. Parameters of monoclinic cell are as follows: 1 = 9.583(2), b = 16.958 (4), c = 18.685 (3) A; β = 105.65 (2), V = 2924 (1) A 3 , Z =4; sp.gr. P2 1 /c. The structure consists of dimer units. Pb-B distance is within 3.23-3.71 (3) A. 5 refs.; 2 figs.; 2 tabs

  19. Synthesis and crystal structure of Pb(Bipy)2B12H12

    International Nuclear Information System (INIS)

    Lagun, V.L.; Orlova, A.M.; Katser, S.B.; Solntsev, K.A.; Kuznetsov, N.T.

    1994-01-01

    Lead complex with B 12 H 12 2- anion and 2,2' bipyridine-lead(2) dodecahydro-closo-dodecaborate di(2,2' bipyridine) is synthesized and characterized by IF, UV and NMR spectrography methods. According to roentgen-structural analysis the crystals belong to monoclinic syngony, sp.gr. C2/m,a=17.872(4), b=18.672(5), c=9.228(7)A, β=109.11(4), V=2910(2)A 3 , Z=4. The structure consists of Pb 2 (Bipy) 4 (B 12 H 12 ) 2 dimeric units. The Pb-B distances are within the limits of 3.313-3.514A. 11 refs.; 2 figs.; 2 tabs

  20. Vitamin B12 in metformin-treated diabetic patients: a cross-sectional study in Brazil Vitamina B12 em pacientes diabéticos usando metformina: um corte transversal no Brasil

    OpenAIRE

    Monique Nervo; Adriano Lubini; Fabiana Viegas Raimundo; Gustavo Adolpho Moreira Faulhaber; Carine Leite; Leonardo Moura Fischer; Tania Weber Furlanetto

    2011-01-01

    OBJECTIVE: The objective of this study was to evaluate the presence of vitamin B12 deficiency and the factors associated with serum vitamin B12 levels in a sample of metformin-treated Brazilian diabetic patients. METHOD: Cross-sectional study. RESULTS: 144 patients were included. Serum vitamin B12 levels were low (< 125 pmol/L) in 10 patients (6.9%) and possibly low (125 - 250 pmol/L) in 53 patients (36.8%). Serum vitamin B12 levels were negatively associated with age (B = -3.17; β= -0.1...

  1. Ultrafast electronic relaxation of excited state vitamin B12 in the gas phase

    International Nuclear Information System (INIS)

    Shafizadeh, Niloufar; Poisson, Lionel; Soep, Benoit

    2008-01-01

    The time evolution of electronically excited vitamin B 12 (cyanocobalamin) has been observed for the first time in the gas phase. It reveals an ultrafast decay to a state corresponding to metal excitation. This decay is interpreted as resulting from a ring to metal electron transfer. This opens the observation of the excited state of other complex biomimetic systems in the gas phase, the key to the characterisation of their complex evolution through excited electronic states

  2. Quantifying the Electrocatalytic Turnover of Vitamin B12-Mediated Dehalogenation on Single Soft Nanoparticles.

    Science.gov (United States)

    Cheng, Wei; Compton, Richard G

    2016-02-12

    We report the electrocatalytic dehalogenation of trichloroethylene (TCE) by single soft nanoparticles in the form of Vitamin B12 -containing droplets. We quantify the turnover number of the catalytic reaction at the single soft nanoparticle level. The kinetic data shows that the binding of TCE with the electro-reduced vitamin in the Co(I) oxidation state is chemically reversible. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Long term treatment with metformin in patients with type 2 diabetes and vitamin B 12

    Directory of Open Access Journals (Sweden)

    Yu V Pankratova

    2012-12-01

    Full Text Available Реферат по статье: De Jager J, Kooy A, Lehert P, Wulffelé MG, van der Kolk J, Bets D, Verburg J, Donker AJ, Stehouwer CD. Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: randomised placebo controlled trial. BMJ. 2010 May 20;340:c2181.

  4. C. elegans MRP-5 Exports Vitamin B12 from Mother to Offspring to Support Embryonic Development.

    Science.gov (United States)

    Na, Huimin; Ponomarova, Olga; Giese, Gabrielle E; Walhout, Albertha J M

    2018-03-20

    Vitamin B12 functions as a cofactor for methionine synthase to produce the anabolic methyl donor S-adenosylmethionine (SAM) and for methylmalonyl-CoA mutase to catabolize the short-chain fatty acid propionate. In the nematode Caenorhabditis elegans, maternally supplied vitamin B12 is required for the development of offspring. However, the mechanism for exporting vitamin B12 from the mother to the offspring is not yet known. Here, we use RNAi of more than 200 transporters with a vitamin B12-sensor transgene to identify the ABC transporter MRP-5 as a candidate vitamin B12 exporter. We show that the injection of vitamin B12 into the gonad of mrp-5 deficient mothers rescues embryonic lethality in the offspring. Altogether, our findings identify a maternal mechanism for the transit of an essential vitamin to support the development of the next generation. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  5. [Determination of soil exchangeable base cations by using atomic absorption spectrophotometer and extraction with ammonium acetate].

    Science.gov (United States)

    Zhang, Yu-ge; Xiao, Min; Dong, Yi-hua; Jiang, Yong

    2012-08-01

    A method to determine soil exchangeable calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) by using atomic absorption spectrophotometer (AAS) and extraction with ammonium acetate was developed. Results showed that the accuracy of exchangeable base cation data with AAS method fits well with the national standard referential soil data. The relative errors for parallel samples of exchangeable Ca and Mg with 66 pair samples ranged from 0.02%-3.14% and 0.06%-4.06%, and averaged to be 1.22% and 1.25%, respectively. The relative errors for exchangeable K and Na with AAS and flame photometer (FP) ranged from 0.06%-8.39% and 0.06-1.54, and averaged to be 3.72% and 0.56%, respectively. A case study showed that the determination method for exchangeable base cations by using AAS was proven to be reliable and trustable, which could reflect the real situation of soil cation exchange properties in farmlands.

  6. Light Absorption Enhancement of Silicon-Based Photovoltaic Devices with Multiple Bandgap Structures of Porous Silicon

    Directory of Open Access Journals (Sweden)

    Kuen-Hsien Wu

    2015-09-01

    Full Text Available Porous-silicon (PS multi-layered structures with three stacked PS layers of different porosity were prepared on silicon (Si substrates by successively tuning the electrochemical-etching parameters in an anodization process. The three PS layers have different optical bandgap energy and construct a triple-layered PS (TLPS structure with multiple bandgap energy. Photovoltaic devices were fabricated by depositing aluminum electrodes of Schottky contacts on the surfaces of the developed TLPS structures. The TLPS-based devices exhibit broadband photoresponses within the spectrum of the solar irradiation and get high photocurrent for the incident light of a tungsten lamp. The improved spectral responses of devices are owing to the multi-bandgap structures of TLPS, which are designed with a layered configuration analog to a tandem cell for absorbing a wider energy range of the incidental sun light. The large photocurrent is mainly ascribed to an enhanced light-absorption ability as a result of applying nanoporous-Si thin films as the surface layers to absorb the short-wavelength light and to improve the Schottky contacts of devices. Experimental results reveal that the multi-bandgap PS structures produced from electrochemical-etching of Si wafers are potentially promising for development of highly efficient Si-based solar cells.

  7. Ultrafast Transient Absorption Spectroscopy of Polymer-Based Organophotoredox Catalysts Mimicking Transition-Metal Complexes

    Science.gov (United States)

    Jamhawi, Abdelqader; Paul, Anam C.; Smith, Justin D.; Handa, Sachin; Liu, Jinjun

    2017-06-01

    Transition-metal complexes of rare earth metals including ruthenium and iridium are most commonly employed as visible-light photocatalysts. Despite their highly important and broad applications, they have many disadvantages including high cost associated with low abundance in earth crust, potential toxicity, requirement of specialized ligands for desired activity, and difficulty in recycling of metal contents as well as associated ligands. Polymer-based organophotoredox catalysts are promising alternatives and possess unique advantages such as easier synthesis from inexpensive starting material, longer excited state life time, broad range of activity, sustainability, and recyclability. In this research talk, time-resolved photoluminescence and femtosecond transient absorption (TA) spectroscopy measurements of three novel polymer-based organophotoredox catalysts will be presented. By our synthetic team, their catalytic activity has been proven in some highly valuable chemical transformations, that otherwise require transition metal complexes. Time-resolved spectroscopic investigations have demonstrated that photoinduced processes in these catalysts are similar to the transition metal complexes. Especially, intramolecular vibrational relaxation, internal conversion, and intersystem crossing from the S1 state to the T1 state all occur on a sub-picosecond timescale. The long lifetime of the T1 state ( 2-3 microsecond) renders these polymers potent oxidizing and reducing agents. A spectroscopic and kinetic model has been developed for global fitting of TA spectra in both the frequency and time domains. Implication of the current ultrafast spectroscopy studies of these novel molecules to their roles in photocatalysis will be discussed.

  8. Mielopatia por deficiência de vitamina B12 apresentando-se como mielite transversa

    Directory of Open Access Journals (Sweden)

    Vasconcellos Luiz Felipe Rocha

    2002-01-01

    Full Text Available As manifestações neurológicas associadas à deficiência de vitamina B12 incluem polineuropatia, mielopatia, demência e neuropatia óptica. O diagnóstico laboratorial é feito através da dosagem sérica de cianocobalamina ou homocisteína e da excreção urinária de ácido metilmalônico. No estudo anatomopatológico observa-se na microscopia a destruição da mielina e de axônios vistos na substância branca. A região mais comumente afetada é o cordão posterior cervical e/ou torácico. O acometimento da coluna lateral é raro, ocorrendo em casos graves e avançados. O tratamento consiste na reposição de vitamina B12 e a resposta depende da gravidade do quadro e do tempo transcorrido entre o inicio dos sintomas e inicio do tratamento. Relatamos o caso de um paciente que apresentou, como manifestação de deficiência de vitamina B12, mielite transversa. O estudo morfológico da medula demonstrou comprometimento dos tractos cortico-espinhais lateral e anterior, da coluna dorsal e ainda do tracto espino-talâmico.

  9. Coenzyme B12 synthesis as a baseline to study metabolite contribution of animal microbiota.

    Science.gov (United States)

    Danchin, Antoine; Braham, Sherazade

    2017-07-01

    Microbial communities thrive in a number of environments. Exploration of their microbiomes - their global genome - may reveal metabolic features that contribute to the development and welfare of their hosts, or chemical cleansing of environments. Yet we often lack final demonstration of their causal role in features of interest. The reason is that we do not have proper baselines that we could use to monitor how microbiota cope with key metabolites in the hosting environment. Here, focusing on animal gut microbiota, we describe the fate of cobalamins - metabolites of the B12 coenzyme family - that are essential for animals but synthesized only by prokaryotes. Microbiota produce the vitamin used in a variety of animals (and in algae). Coprophagy plays a role in its management. For coprophobic man, preliminary observations suggest that the gut microbial production of vitamin B12 plays only a limited role. By contrast, the vitamin is key for structuring microbiota. This implies that it is freely available in the environment. This can only result from lysis of the microbes that make it. A consequence for biotechnology applications is that, if valuable for their host, B12-producing microbes should be sensitive to bacteriophages and colicins, or make spores. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  10. Possible Involvement of Hydrosulfide in B12-Dependent Methyl Group Transfer

    Directory of Open Access Journals (Sweden)

    John I. Toohey

    2017-04-01

    Full Text Available Evidence from several fields of investigation lead to the hypothesis that the sulfur atom is involved in vitamin B12-dependent methyl group transfer. To compile the evidence, it is necessary to briefly review the following fields: methylation, the new field of sulfane sulfur/hydrogen sulfide (S°/H2S, hydrosulfide derivatives of cobalamins, autoxidation of hydrosulfide radical, radical S-adenosylmethionine methyl transfer (RSMT, and methionine synthase (MS. Then, new reaction mechanisms for B12-dependent methyl group transfer are proposed; the mechanisms are facile and overcome difficulties that existed in previously-accepted mechanisms. Finally, the theory is applied to the effect of S°/H2S in nerve tissue involving the “hypomethylation theory” that was proposed 50 years ago to explain the neuropathology resulting from deficiency of vitamin B12 or folic acid. The conclusions are consistent with emerging evidence that sulfane sulfur/hydrogen sulfide may be beneficial in treating Alzheimer’s disease.

  11. Crosstalk between Vitamins A, B12, D, K, C, and E Status and Arterial Stiffness

    Science.gov (United States)

    Luca, Constantin Tudor

    2017-01-01

    Arterial stiffness is associated with cardiovascular risk, morbidity, and mortality. The present paper reviews the main vitamins related to arterial stiffness and enabling destiffening, their mechanisms of action, providing a brief description of the latest studies in the area, and their implications for primary cardiovascular prevention, clinical practice, and therapy. Despite inconsistent evidence for destiffening induced by vitamin supplementation in several randomized clinical trials, positive results were obtained in specific populations. The main mechanisms are related to antiatherogenic effects, improvement of endothelial function (vitamins A, C, D, and E) and metabolic profile (vitamins A, B12, C, D, and K), inhibition of the renin-angiotensin-aldosterone system (vitamin D), anti-inflammatory (vitamins A, D, E, and K) and antioxidant effects (vitamins A, C, and E), decrease of homocysteine level (vitamin B12), and reversing calcification of arteries (vitamin K). Vitamins A, B12, C, D, E, and K status is important in evaluating cardiovascular risk, and vitamin supplementation may be an effective, individualized, and inexpensive destiffening therapy. PMID:28167849

  12. Disposable pencil graphite electrode modified with peptide nanotubes for Vitamin B12 analysis

    International Nuclear Information System (INIS)

    Pala, Betül Bozdoğan; Vural, Tayfun; Kuralay, Filiz; Çırak, Tamer; Bolat, Gülçin; Abacı, Serdar; Denkbaş, Emir Baki

    2014-01-01

    In this study, peptide nanostructures from diphenylalanine were synthesized in various solvents with various polarities and characterized with Scanning Electron Microscopy (SEM) and Powder X-ray Diffraction (PXRD) techniques. Formation of peptide nanofibrils, nanovesicles, nanoribbons, and nanotubes was observed in different solvent mediums. In order to investigate the effects of peptide nanotubes (PNT) on electrochemical behavior of disposable pencil graphite electrodes (PGE), electrode surfaces were modified with fabricated peptide nanotubes. Electrochemical activity of the pencil graphite electrode was increased with the deposition of PNTs on the surface. The effects of the solvent type, the peptide nanotube concentration, and the passive adsorption time of peptide nanotubes on pencil graphite electrode were studied. For further electrochemical studies, electrodes were modified for 30 min by immobilizing PNTs, which were prepared in water at 6 mg/mL concentration. Vitamin B 12 analyses were performed by the Square Wave (SW) voltammetry method using modified PGEs. The obtained data showed linearity over the range of 0.2 μM and 9.50 μM Vitamin B 12 concentration with high sensitivity. Results showed that PNT modified PGEs were highly simple, fast, cost effective, and feasible for the electro-analytical determination of Vitamin B 12 in real samples.

  13. Transport Measurements and Synchrotron-Based X-Ray Absorption Spectroscopy of Iron Silicon Germanide Grown by Molecular Beam Epitaxy

    Science.gov (United States)

    Elmarhoumi, Nader; Cottier, Ryan; Merchan, Greg; Roy, Amitava; Lohn, Chris; Geisler, Heike; Ventrice, Carl, Jr.; Golding, Terry

    2009-03-01

    Some of the iron-based metal silicide and germanide phases have been predicted to be direct band gap semiconductors. Therefore, they show promise for use as optoelectronic materials. We have used synchrotron-based x-ray absorption spectroscopy to study the structure of iron silicon germanide films grown by molecular beam epitaxy. A series of Fe(Si1-xGex)2 thin films (2000 -- 8000å) with a nominal Ge concentration of up to x = 0.04 have been grown. X-ray absorption near edge structure (XANES) and extended x-ray absorption fine structure (EXAFS) measurements have been performed on the films. The nearest neighbor co-ordination corresponding to the β-FeSi2 phase of iron silicide provides the best fit with the EXAFS data. Temperature dependent (20 coefficient was calculated. Results suggest semiconducting behavior of the films which is consistent with the EXAFS results.

  14. Low vitamin B12 levels among newly-arrived refugees from Bhutan, Iran and Afghanistan: a multicentre Australian study.

    Directory of Open Access Journals (Sweden)

    Jill Benson

    Full Text Available BACKGROUND: Vitamin B12 deficiency is prevalent in many countries of origin of refugees. Using a threshold of 5% above which a prevalence of low Vitamin B12 is indicative of a population health problem, we hypothesised that Vitamin B12 deficiency exceeds this threshold among newly-arrived refugees resettling in Australia, and is higher among women due to their increased risk of food insecurity. This paper reports Vitamin B12 levels in a large cohort of newly arrived refugees in five Australian states and territories. METHODS: In a cross-sectional descriptive study, we collected Vitamin B12, folate and haematological indices on all refugees (n = 916; response rate 94% of eligible population who had been in Australia for less than one year, and attended one of the collaborating health services between July 2010 and July 2011. RESULTS: 16.5% of participants had Vitamin B12 deficiency (<150 pmol/L. One-third of participants from Iran and Bhutan, and one-quarter of participants from Afghanistan had Vitamin B12 deficiency. Contrary to our hypothesis, low Vitamin B12 levels were more prevalent in males than females. A higher prevalence of low Vitamin B12 was also reported in older age groups in some countries. The sensitivity of macrocytosis in detecting Vitamin B12 deficiency was only 4.6%. CONCLUSION: Vitamin B12 deficiency is an important population health issue in newly-arrived refugees from many countries. All newly-arrived refugees should be tested for Vitamin B12 deficiency. Ongoing research should investigate causes, treatment, and ways to mitigate food insecurity, and the contribution of such measures to enhancing the health of the refugee communities.

  15. Imerslund-Grasbeck syndrome in a Chinese family with distinct skin lesions refractory to vitamin B12.

    OpenAIRE

    Lin, S H; Sourial, N A; Lu, K C; Hsueh, E J

    1994-01-01

    Two brothers in a Chinese family with selective malabsorption of vitamin B12 associated with proteinuria (Imerslund-Grasbeck syndrome) presented with widespread mottled skin pigmentation, termed poikiloderma. In contrast to anaemia, this pigmentary disturbance remained unresponsive to vitamin B12 replacement. This is different from the reported hyperpigmentation sometimes seen in vitamin B12 deficiency which is reversible following treatment. As far as is known, an irreversible and persistent...

  16. A combined supplementation of vitamin B12 and omega-3 fatty acids across two generations improves cardiometabolic variables in rats.

    Science.gov (United States)

    Khaire, Amrita; Rathod, Richa; Randhir, Karuna; Kale, Anvita; Joshi, Sadhana

    2016-09-14

    Our earlier studies indicate that micronutrients (vitamin B12, folic acid) and omega-3 fatty acids especially docosahexaenoic acid (DHA) are interlinked in one carbon cycle. The present study examines the effects of a sustained vitamin B12 deficiency/supplementation in the presence of omega-3 fatty acids across two generations on the pregnancy outcome and cardiometabolic profile [blood pressure, plasma lipid profile (cholesterol and triglycerides), plasma/liver fatty acid profile and hepatic lipid metabolism] in the second generation adult Wistar rat offspring. Two generations of animals were fed the following diets: control; vitamin B12 deficient; vitamin B12 supplemented; vitamin B12 deficient diet supplemented with omega-3 fatty acids; vitamin B12 and omega-3 fatty acid supplemented diets. Male offspring were sacrificed at 3 months of age. Vitamin B12 deficiency lowered the weight gain (p blood pressure, and lowered the levels of plasma/liver DHA (p lipid profile. Vitamin B12 supplementation showed weight gain, blood pressure and the fatty acid profile similar to the control. However, it increased (p acid supplementation to the vitamin B12 deficient group lowered the weight gain although the levels of cardiometabolic variables were comparable to the control. Omega-3 fatty acid supplementation in the presence of vitamin B12 improved the pregnancy outcome and all cardio-metabolic variables. Our study highlights the adverse effects of sustained vitamin B12 deficiency across two generations on the pregnancy outcome, fatty acid profile and blood pressure while a combined supplementation of vitamin B12 and omega-3 fatty acids is beneficial.

  17. Techno-functional differentiation of two vitamin B12 producing Lactobacillus plantarum strains: an elucidation for diverse future use.

    Science.gov (United States)

    Bhushan, Bharat; Tomar, S K; Chauhan, Arun

    2017-01-01

    An appropriate selection of Lactobacillus strain (probiotic/starter/functional) on the basis of its techno-functional characteristics is required before developing a novel fermented functional food. We compared vitamin B 12 (B 12 , cobalamin) producing Lactobacillus plantarum isolates, BHM10 and BCF20, for functional (vitamin over-production, genomic insight to B 12 structural genes, and probiotic attributes) and technological [milks (skim and soy) fermentation and B 12 bio-fortification] characteristics. Addition of B 12 precursors (5-amonolevulinate and dimethylbenzimidazole) to cobalamin-free fermentation medium increased vitamin production in BHM10, BCF20, and DSM20016 (a positive standard) by 3.4-, 4.4-, and 3.86-folds, respectively. Three important B 12 structural genes were detected in L. plantarum species (strains BHM10 and BCF20) by PCR for the first time. The gene sequences were submitted to NCBI GenBank and found phylogenetically closer to respective sequences in B 12 producing Lactobacillus reuteri strains. During comparative probiotic testing, BCF20 showed significantly higher (p < 0.05 to p < 0.001) gastrointestinal tolerance and cell surface hydrophobicity (p < 0.05) than BHM10. Moreover, only BCF20 was found positive for BSH activity and also exhibited comparatively better antagonistic potential against potent pathogens. Conversely, high acid and bile susceptible strain BHM10 displayed significantly higher soy milk fermentation and resultant B 12 bio-fortification abilities during technological testing. Two B 12 quantification techniques, UFLC and competitive immunoassay, confirmed the in vitro and in situ bio-production of bio-available form of B 12 after BHM10 fermentation. Conclusively, techno-functional differentiation of two B 12 producing strains elucidates their diverse future use; BCF20 either for B 12 over-production (in vitro) or as a probiotic candidate, while BHM10 for cobalamin bio-fortification (in situ) in soy milk.

  18. Mammographic x-ray unit kilovoltage test tool based on k-edge absorption effect.

    Science.gov (United States)

    Napolitano, Mary E; Trueblood, Jon H; Hertel, Nolan E; David, George

    2002-09-01

    A simple tool to determine the peak kilovoltage (kVp) of a mammographic x-ray unit has been designed. Tool design is based on comparing the effect of k-edge discontinuity of the attenuation coefficient for a series of element filters. Compatibility with the mammography accreditation phantom (MAP) to obtain a single quality control film is a second design objective. When the attenuation of a series of sequential elements is studied simultaneously, differences in the absorption characteristics due to the k-edge discontinuities are more evident. Specifically, when the incident photon energy is higher than the k-edge energy of a number of the elements and lower than the remainder, an inflection may be seen in the resulting attenuation data. The maximum energy of the incident photon spectra may be determined based on this inflection point for a series of element filters. Monte Carlo photon transport analysis was used to estimate the photon transmission probabilities for each of the sequential k-edge filter elements. The photon transmission corresponds directly to optical density recorded on mammographic x-ray film. To observe the inflection, the element filters chosen must have k-edge energies that span a range greater than the expected range of the end point energies to be determined. For the design, incident x-ray spectra ranging from 25 to 40 kVp were assumed to be from a molybdenum target. Over this range, the k-edge energy changes by approximately 1.5 keV between sequential elements. For this design 21 elements spanning an energy range from 20 to 50 keV were chosen. Optimum filter element thicknesses were calculated to maximize attenuation differences at the k-edge while maintaining optical densities between 0.10 and 3.00. Calculated relative transmission data show that the kVp could be determined to within +/-1 kV. To obtain experimental data, a phantom was constructed containing 21 different elements placed in an acrylic holder. MAP images were used to determine

  19. Neural network based control of an absorption column in the process of bioethanol production

    Directory of Open Access Journals (Sweden)

    Eduardo Eyng

    2009-08-01

    Full Text Available Gaseous ethanol may be recovered from the effluent gas mixture of the sugar cane fermentation process using a staged absorption column. In the present work, the development of a nonlinear controller, based on a neural network inverse model (ANN controller, was proposed and tested to manipulate the absorbent flow rate in order to control the residual ethanol concentration in the effluent gas phase. Simulation studies were carried out, in which a noise was applied to the ethanol concentration signals from the rigorous model. The ANN controller outperformed the dynamic matrix control (DMC when step disturbances were imposed to the gas mixture composition. A security device, based on a conventional feedback algorithm, and a digital filter were added to the proposed strategy to improve the system robustness when unforeseen operating and environmental conditions occured. The results demonstrated that ANN controller was a robust and reliable tool to control the absorption column.Deseja-se recuperar o etanol perdido por evaporação durante o processo de fermentação da cana-de-açúcar. Para tanto, faz-se uso de uma coluna de absorção. O controle da concentração de etanol no efluente gasoso da coluna é realizado pela manipulação da vazão de solvente, sendo esta determinada pelo controlador não linear proposto, baseado em um modelo inverso de redes neurais (controlador ANN. Foram feitas simulações adicionando-se um sinal de ruído a medida de concentração de etanol na fase gasosa. Quando perturbações degrau foram inseridas na mistura gasosa afluente, o controlador ANN demonstrou desempenho superior ao controle por matriz dinâmica (DMC. Um dispositivo de segurança, baseado em um controlador feedback convencional, e um filtro digital foram implementados à estratégia de controle proposta para agregar robustez no tratamento de distúrbios ocorridos no ambiente operacional. Os resultados demonstraram que o controlador ANN é uma

  20. Mammographic x-ray unit kilovoltage test tool based on k-edge absorption effect

    International Nuclear Information System (INIS)

    Napolitano, Mary E.; Trueblood, Jon H.; Hertel, Nolan E.; David, George

    2002-01-01

    A simple tool to determine the peak kilovoltage (kVp) of a mammographic x-ray unit has been designed. Tool design is based on comparing the effect of k-edge discontinuity of the attenuation coefficient for a series of element filters. Compatibility with the mammography accreditation phantom (MAP) to obtain a single quality control film is a second design objective. When the attenuation of a series of sequential elements is studied simultaneously, differences in the absorption characteristics due to the k-edge discontinuities are more evident. Specifically, when the incident photon energy is higher than the k-edge energy of a number of the elements and lower than the remainder, an inflection may be seen in the resulting attenuation data. The maximum energy of the incident photon spectra may be determined based on this inflection point for a series of element filters. Monte Carlo photon transport analysis was used to estimate the photon transmission probabilities for each of the sequential k-edge filter elements. The photon transmission corresponds directly to optical density recorded on mammographic x-ray film. To observe the inflection, the element filters chosen must have k-edge energies that span a range greater than the expected range of the end point energies to be determined. For the design, incident x-ray spectra ranging from 25 to 40 kVp were assumed to be from a molybdenum target. Over this range, the k-edge energy changes by approximately 1.5 keV between sequential elements. For this design 21 elements spanning an energy range from 20 to 50 keV were chosen. Optimum filter element thicknesses were calculated to maximize attenuation differences at the k-edge while maintaining optical densities between 0.10 and 3.00. Calculated relative transmission data show that the kVp could be determined to within ±1 kV. To obtain experimental data, a phantom was constructed containing 21 different elements placed in an acrylic holder. MAP images were used to determine

  1. Management of light absorption in extraordinary optical transmission based ultra-thin-film tandem solar cells

    International Nuclear Information System (INIS)

    Mashooq, Kishwar; Talukder, Muhammad Anisuzzaman

    2016-01-01

    Although ultra-thin-film solar cells can be attractive in reducing the cost, they suffer from low absorption as the thickness of the active layer is usually much smaller than the wavelength of incident light. Different nano-photonic techniques, including plasmonic structures, are being explored to increase the light absorption in ultra-thin-film solar cells. More than one layer of active materials with different energy bandgaps can be used in tandem to increase the light absorption as well. However, due to different amount of light absorption in different active layers, photo-generated currents in different active layers will not be the same. The current mismatch between the tandem layers makes them ineffective in increasing the efficiency. In this work, we investigate the light absorption properties of tandem solar cells with two ultra-thin active layers working as two subcells and a metal layer with periodically perforated holes in-between the two subcells. While the metal layer helps to overcome the current mismatch, the periodic holes increase the absorption of incident light by helping extraordinary optical transmission of the incident light from the top to the bottom subcell, and by coupling the incident light to plasmonic and photonic modes within ultra-thin active layers. We extensively study the effects of the geometry of holes in the intermediate metal layer on the light absorption properties of tandem solar cells with ultra-thin active layers. We also study how different metals in the intermediate layer affect the light absorption; how the geometry of holes in the intermediate layer affects the absorption when the active layer materials are changed; and how the intermediate metal layer affects the collection of photo-generated electron-hole pairs at the terminals. We find that in a solar cell with 6,6-phenyl C61-butyric acid methyl ester top subcell and copper indium gallium selenide bottom subcell, if the periodic holes in the metal layer are square or

  2. Management of light absorption in extraordinary optical transmission based ultra-thin-film tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Mashooq, Kishwar; Talukder, Muhammad Anisuzzaman, E-mail: anis@eee.buet.ac.bd [Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1205 (Bangladesh)

    2016-05-21

    Although ultra-thin-film solar cells can be attractive in reducing the cost, they suffer from low absorption as the thickness of the active layer is usually much smaller than the wavelength of incident light. Different nano-photonic techniques, including plasmonic structures, are being explored to increase the light absorption in ultra-thin-film solar cells. More than one layer of active materials with different energy bandgaps can be used in tandem to increase the light absorption as well. However, due to different amount of light absorption in different active layers, photo-generated currents in different active layers will not be the same. The current mismatch between the tandem layers makes them ineffective in increasing the efficiency. In this work, we investigate the light absorption properties of tandem solar cells with two ultra-thin active layers working as two subcells and a metal layer with periodically perforated holes in-between the two subcells. While the metal layer helps to overcome the current mismatch, the periodic holes increase the absorption of incident light by helping extraordinary optical transmission of the incident light from the top to the bottom subcell, and by coupling the incident light to plasmonic and photonic modes within ultra-thin active layers. We extensively study the effects of the geometry of holes in the intermediate metal layer on the light absorption properties of tandem solar cells with ultra-thin active layers. We also study how different metals in the intermediate layer affect the light absorption; how the geometry of holes in the intermediate layer affects the absorption when the active layer materials are changed; and how the intermediate metal layer affects the collection of photo-generated electron-hole pairs at the terminals. We find that in a solar cell with 6,6-phenyl C61-butyric acid methyl ester top subcell and copper indium gallium selenide bottom subcell, if the periodic holes in the metal layer are square or

  3. Development of gamma-ray absorption and scattering simulation platform based on MCNP

    International Nuclear Information System (INIS)

    Lai Wanchang; Chen Henggui; Zhang Zhen; Chen Xiaoqiang

    2010-01-01

    It describes a γ-ray absorption and scattering simulation platform centering on MCNP, and developed corresponding accessories on the basis of the MCNP. Simulation of this simulation platform can be 93 kinds of single-quality materials and 2-3 kinds of multi-element mixture absorption experiment, simulating the absorption thickness of 0-100cm, and the thickness increment in 0.001cm. The media of Scattering Simulation is from the Li to the Am, the angle between the simulation measuring degree and incident ray direction is from-90 to 90, the angle in increments in 1 degree. (authors)

  4. EVALUATION OF SERUM VITAMIN B12 LEVELS IN TYPE 2 DIABETES PATIENTS ON METFORMIN THERAPY ATTENDING A TERTIARY CARE HOSPITAL

    Directory of Open Access Journals (Sweden)

    Anand Kalakappa Koppad

    2017-11-01

    Full Text Available BACKGROUND Type 2 Diabetes Mellitus (T2DM is an endocrine disorder and a heterogeneous group of syndromes characterised by an elevation of fasting blood glucose that is caused by a relative or absolute deficiency in insulin. Serum vitamin B12 levels have been reported to be inversely associated with the dose and duration of metformin use. Vitamin B12 deficiency is a treatable condition. However, there is insufficient data regarding prevalence of vitamin B12 deficiency in the South Indian population. Hence, the study was undertaken to evaluate serum vitamin B12 levels in T2DM on metformin therapy. MATERIALS AND METHODS A total of 100 T2DM patients attending Outpatient Department (OPD or admitted under Department of General Medicine of KIMS, Hubli, during the time period of 2 years were taken for study considering the inclusion and exclusion criteria. Qualifying patients underwent detailed history, clinical examination, routine investigation and vitamin B12 estimation. RESULTS Majority were in the age group of 45-59 years making 42% of the total. The age group in most patients having vitamin B12 deficiency was >60 years. Males had more vitamin B12 deficiency forming 54.5%. Vitamin B12 deficiency was more in hypertensive group accounting for 71.4%, which was statistically significant. Most of the vitamin B12 deficiency patients had diabetes duration >10 years. Most of the vitamin B12 deficient patients were taking metformin therapy for longer years (≥10 years and in higher dose (>2 g/day. Most of the vitamin B12 deficient diabetes patients were overweight forming 52.5% of the total. CONCLUSION Longer duration of diabetes increases the risk of developing vitamin B12 deficiency on metformin therapy. The higher dose of metformin intake had inverse relation with vitamin B12 levels. Longer duration of metformin intake causes vitamin B12 deficiency and hence should be screened for vitamin B12 deficiency and can be supplemented with vitamin B12.

  5. Association of Helicobacter pylori infection with serum vitamin B12 level in women of gestational age in Khorram Abad

    Directory of Open Access Journals (Sweden)

    fatemeh Yari

    2006-02-01

    Findings: There was no significant difference between mean age of HP positive and HP negative participants. 76 out of 110 (72.2% samples were HP positive. The rate of HP seropositivity was significantly higher in patients with serum vitamin B12 level less than 12 pg/ml. who had lower and moderate vitamin B12 levels (145-180 pg/ml, that is 94% vs 64.5%, P<0.013. Conclusion: High HP seropositivity rate among patients with low-normal less serum vitamin B12 levels than normal indicates that there may be an association between HP infection and serum vitamin B12 levels.

  6. Tri-generation System based on Municipal Waste Gasification, Fuel Cell and an Absorption Chiller

    Directory of Open Access Journals (Sweden)

    Giannis Katsaros

    2018-03-01

    Full Text Available The present work focuses on the design of a novel tri-generation system based on gasification of municipal solid wastes, a solid oxide fuel cell and an ammonia-water absorption chiller. Tri-generation systems can be implemented in buildings such as hospitals and hotels, where there is a continuous and large demand for electricity, heating and cooling. The system is modelled in Aspen Plus and the influence of different operating parameters on the system performance was studied. The findings suggest that low air equivalent ratios and high gasification temperatures enhance the overall system performance. Syngas cleaning with metal sorbents zinc oxide and sodium bicarbonate for the removal of hydrogen sulfide and hydrogen chloride concentrations proved to be very effective, reducing the concentration of contaminants to < 1 ppm (part per million levels. The possibility of covering the demand profiles of a specific building was also investigated: the system could fully meet the electricity and cooling demands, whereas the heat requirements could be satisfied only up to 55%. Moreover, assuming 20 years of operation, the payback period was 4.5 years and the net present value exceeded 5 million euros.

  7. Second law-based thermodynamic analysis of water-lithium bromide absorption refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Muhsin [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Uludag University, TR 16059, Bursa (Turkey)]. E-mail: mkilic@uludag.edu.tr; Kaynakli, Omer [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Uludag University, TR 16059, Bursa (Turkey)

    2007-08-15

    In this study, the first and the second law of thermodynamics are used to analyze the performance of a single-stage water-lithium bromide absorption refrigeration system (ARS) when some working parameters are varied. A mathematical model based on the exergy method is introduced to evaluate the system performance, exergy loss of each component and total exergy loss of all the system components. Parameters connected with performance of the cycle-circulation ratio (CR), coefficient of performance (COP), Carnot coefficient of performance (COP{sub c} ), exergetic efficiency ({xi}) and efficiency ratio ({tau})-are calculated from the thermodynamic properties of the working fluids at various operating conditions. Using the developed model, the effect of main system temperatures on the performance parameters of the system, irreversibilities in the thermal process and non-dimensional exergy loss of each component are analyzed in detail. The results show that the performance of the ARS increases with increasing generator and evaporator temperatures, but decreases with increasing condenser and absorber temperatures. Exergy losses in the expansion valves, pump and heat exchangers, especially refrigerant heat exchanger, are small compared to other components. The highest exergy loss occurs in the generator regardless of operating conditions, which therefore makes the generator the most important component of the cycle.

  8. Second law-based thermodynamic analysis of water-lithium bromide absorption refrigeration system

    International Nuclear Information System (INIS)

    Kilic, Muhsin; Kaynakli, Omer

    2007-01-01

    In this study, the first and the second law of thermodynamics are used to analyze the performance of a single-stage water-lithium bromide absorption refrigeration system (ARS) when some working parameters are varied. A mathematical model based on the exergy method is introduced to evaluate the system performance, exergy loss of each component and total exergy loss of all the system components. Parameters connected with performance of the cycle-circulation ratio (CR), coefficient of performance (COP), Carnot coefficient of performance (COP c ), exergetic efficiency (ξ) and efficiency ratio (τ)-are calculated from the thermodynamic properties of the working fluids at various operating conditions. Using the developed model, the effect of main system temperatures on the performance parameters of the system, irreversibilities in the thermal process and non-dimensional exergy loss of each component are analyzed in detail. The results show that the performance of the ARS increases with increasing generator and evaporator temperatures, but decreases with increasing condenser and absorber temperatures. Exergy losses in the expansion valves, pump and heat exchangers, especially refrigerant heat exchanger, are small compared to other components. The highest exergy loss occurs in the generator regardless of operating conditions, which therefore makes the generator the most important component of the cycle

  9. Influence of hydrogen absorption on magnetic ordering in some zirconium-based Laves phase compounds

    International Nuclear Information System (INIS)

    Fujii, H.; Pourarian, F.; Wallace, W.E.

    1982-01-01

    Magnetization measurements were carried out on several zirconium-based hexagonal Laves phase compounds, i.e. the ZrMnsub(2+delta), (Zr,Ti)Mn 2 , Zr(Mn,Fe) 2 and Zr(Fe,Al) 2 systems and their hydrides. The absorbed hydrogen leads to a large increase (20%-30%) in volume without a change in the crystal structure. ZrMnsub(2+delta) is a weak Pauli paramagnet but becomes a spin glass near-ferromagnet by hydriding, indicating that the manganese moments are subjected to competing ferromagnetic and antiferromagnetic coupling tendencies. In the (Zrsub(1-x)Tisub(x))Mn 2 hydrides, ferromagnetic, spin-glass-like, ferromagnetic and antiferromagnetic behaviors appear at 4.2 K in the sequence of increasing x and/or decrease in hydrogen concentration. In the Zr(Mn,Fe) 2 system, the hydrogen absorption increases both the magnetic moments and the magnetic transition temperatures, while absorbed hydrogen leads to suppression of ferromagnetism in the Zr(Fe,Al) 2 system. These varied and complex magnetic behaviors are attributed to the effects of (1) variations in the interatomic distances, (2) changes in the 3d electron concentration and (3) varying local hydrogen concentrations occurring as a result of statistical fluctuations. (Auth.)

  10. Optical resonance-enhanced absorption-based near-field immunochip biosensor for allergen detection.

    Science.gov (United States)

    Maier, Irene; Morgan, Michael R A; Lindner, Wolfgang; Pittner, Fritz

    2008-04-15

    An optical immunochip biosensor has been developed as a rapid method for allergen detection in complex food matrixes, and its application evaluated for the detection of the egg white allergens, ovalbumin and ovomucoid. The optical near-field phenomenon underlying the basic principle of the sensor design is called resonance-enhanced absorption (REA), which utilizes gold nanoparticles (Au NPs) as signal transducers in a highly sensitive interferometric setup. Using this approach, a novel, simple, and rapid colorimetric solid-phase immunoassay on a planar chip substrate was realized in direct and sandwich assay formats, with a detection system that does not require any instrumentation for readout. Semiquantitative immunochemical responses are directly visible to the naked eye of the analyst. The biosensor shows concentration-dependent color development by capturing antibody-functionalized Au NPs on allergen-coated chips and has a detection limit of 1 ng/mL. To establish a rapid method, we took advantage of the physicochemical microenvironment of the Au NP-antibody bioconjugate to be bound directly over an interacting poly(styrene-methyl methacrylate) interlayer by an immobilized antigen. In the direct assay format, a coating time with allergen of only 5 min under "soft" nondenaturing conditions was sufficient for accurate reproducibility and sensitivity. In conclusion, the REA-based immunochip sensor is easy to fabricate, is reproducible and selective in its performance, has minimal technical requirements, and will enable high-throughput screening of affinity binding interactions in technological and medical applications.

  11. Deciphering complex, functional structures with synchrotron-based absorption and phase contrast tomographic microscopy

    Science.gov (United States)

    Stampanoni, M.; Reichold, J.; Weber, B.; Haberthür, D.; Schittny, J.; Eller, J.; Büchi, F. N.; Marone, F.

    2010-09-01

    Nowadays, thanks to the high brilliance available at modern, third generation synchrotron facilities and recent developments in detector technology, it is possible to record volumetric information at the micrometer scale within few minutes. High signal-to-noise ratio, quantitative information on very complex structures like the brain micro vessel architecture, lung airways or fuel cells can be obtained thanks to the combination of dedicated sample preparation protocols, in-situ acquisition schemes and cutting-edge imaging analysis instruments. In this work we report on recent experiments carried out at the TOMCAT beamline of the Swiss Light Source [1] where synchrotron-based tomographic microscopy has been successfully used to obtain fundamental information on preliminary models for cerebral fluid flow [2], to provide an accurate mesh for 3D finite-element simulation of the alveolar structure of the pulmonary acinus [3] and to investigate the complex functional mechanism of fuel cells [4]. Further, we introduce preliminary results on the combination of absorption and phase contrast microscopy for the visualization of high-Z nanoparticles in soft tissues, a fundamental information when designing modern drug delivery systems [5]. As an outlook we briefly discuss the new possibilities offered by high sensitivity, high resolution grating interferomtery as well as Zernike Phase contrast nanotomography [6].

  12. Analysis of urinary stone based on a spectrum absorption FTIR-ATR

    International Nuclear Information System (INIS)

    Asyana, V; Haryanto, F; Fitri, L A; Ridwan, T; Anwary, F; Soekersi, H

    2016-01-01

    This research analysed the urinary stone by measuring samples using Fourier transform infrared-attenuated total reflection spectroscopy and black box analysis. The main objective of this study is to find kinds of urinary stone and determine a total spectrum, which is a simple model of the chemical and mineral composition urinary stone through black box analysis using convolution method. The measurements result showed that kinds of urinary stone were pure calcium oxalate monohydrate, ion amino acid calcium oxalate monohydrate, a mixture of calcium oxalate monohydrate with calcium phosphate, a mixture of ion amino acid calcium oxalate monohydrate and calcium phosphate,pure uric acid, ion amino acid uric acid, and a mixture of calcium oxalate monohydrate with ion amino acid uric acid. The results of analysis of black box showed characteristics as the most accurate and precise to confirm the type of urinary stones based on theregion absorption peak on a graph, the results of the convolution, and the shape of the total spectrum on each urinary stones. (paper)

  13. Development of a portable heavy-water leak sensor based on laser absorption spectroscopy

    International Nuclear Information System (INIS)

    Lee, Lim; Park, Hyunmin; Kim, Taek-Soo; Kim, Minho; Jeong, Do-Young

    2016-01-01

    Highlights: • We developed a compact and portable laser sensor for a detection of heavy water leakage. • The sensor is wearable and also easy to use to search for the leak point. • It is sensitive enough to find invisible very tiny leaks. - Abstract: A compact and portable leak sensor based on cavity enhanced absorption spectroscopy has been newly developed for a detection of heavy water leakage which may happen in the facilities using heavy water such as pressurized heavy water reactor (PHWR). The developed portable sensor is suitable as an individual instrument for the measuring leak rate and finding the leak location because it is sufficiently compact in size and weight and operated by using an internal battery. In the performance test, the minimum detectable leak rate was estimated as 0.05 g/day from the calibration curve. This new sensor is expected to be a reliable and promising device for the detection of heavy water leakage since it has advantages on real-time monitoring and early detection for nuclear safety.

  14. [Efficiency of hemoperfusion on clearing thallium based on atomic absorption spectrometry].

    Science.gov (United States)

    Tian, Tian; Wang, Yongan; Nie, Zhiyong; Wang, Jiao; Peng, Xiaobo; Yuan, Ye; Li, Wanhua; Qiu, Zewu; Xue, Yanping; Xiong, Yiru

    2015-04-01

    To determine thallium in whole blood by atomic absorption detection method, and to investigate the eliminating effect of hemoperfusion (HP) for thallium in blood. The blood of Beagle dogs which had not exposed to thallium before were obtained for preparation of thallium nitrate ( TlNO3 )-containing solution in three concentrations according to the conversion formula based on animal weight and volume of blood. HP was performed in the simulated in vivo environment. The content of TlNO3 in blood of the next group was determined on the amount of TlNO3 for the last HP of the former dose group. Thallium quantity in different samples was measured with atomic absorption spectrometer blood samples before and after HP. Finally, the thallium concentration in blood was analyzed statistically. Thallium concentrations showed a good linear relationship in the range of 0-200 μg/L (r = 0.998 4). The intra-day precision (RSD) was lower than 4.913%, the intra-day recovery rate was 96.2%-111.9%; the inter-day precision (RSD) was lower than 7.502%, the inter-day recovery rate was 89.6%-105.2%. The concentration of thallium in blood was significantly reduced after HP per time in high, middle, and low dose groups [(453.43 ± 27.80) mg/L to (56.09 ± 14.44) mg/L in high dose group, F = 8.820, P = 0.003; (64.51 ± 13.60) mg/L to (3.19 ± 0.23) mg/L in middle dose group, F = 36.312, P = 0.000; (5.40 ± 0.98) mg/L to (0.38 ± 0.25) mg/L in low dose group, F = 46.240, P = 0.000 ]. The adsorption rate of four times of HP in high, middle and low dose group were (87.63 ± 2.48 )%, (95.06 ± 1.54 )% and (92.76 ± 4.87)%, respectively, without significant difference (F = 4.231, P = 0.070). The method for measuring thallium was established, and it shows a very stable, simple, sensitive for determination of thallium. HP can effectively remove thallium from blood. Thallium concentration can be reduced by 90% after four times of HP. HP is also effective even when thallium concentration is not high.

  15. Improved water and sodium absorption from oral rehydration solutions based on rice syrup in a rat model of osmotic diarrhea.

    Science.gov (United States)

    Wapnir, R A; Litov, R E; Zdanowicz, M M; Lifshitz, F

    1991-04-01

    Rice syrup solids, rice protein, and casein hydrolysate were added to experimental oral rehydration solutions in various combinations and tested in a rat intestinal perfusion system. Chronic osmotic diarrhea was induced in juvenile rats by supplying the cathartic agents, magnesium citrate and phenolphthalein, in their drinking water for 1 week. The experimental oral rehydration solutions were compared with standard oral rehydration solutions containing 20 gm/L or 30 gm/L of glucose and with each other to determine if there were significant differences in net water, sodium, or potassium absorption. An oral rehydration solution containing 30 gm/L of rice syrup solids had a net water absorption rate significantly higher than that of the standard 20 gm/L glucose-based oral rehydration solution (2.1 +/- 0.62 versus 1.5 +/- 0.48 microliters/[min x cm], p less than 0.05). Casein hydrolysate did not significantly affect net water absorption. However, combinations of 30 gm/L rice syrup solids and 5 gm/L casein hydrolysate significantly increased (p less than 0.05) net sodium and potassium absorption compared with the 20 gm/L glucose-based oral rehydration solution but not versus rice syrup solids alone. Oral rehydration solutions containing 30 gm/L rice syrup solids plus 5 gm/L rice protein, and 30 gm/L rice syrup solids plus 5 gm/L casein hydrolysate, had net water absorption rates significantly higher than the rate of a 30 gm/L glucose-based oral rehydration solution (2.5 +/- 0.36 and 2.4 +/- 0.38, respectively, versus 0.87 +/- 0.40 microliters/[min x cm], p less than 0.05). Rice protein and casein hydrolysate, however, did not significantly affect net water, sodium, or potassium absorption when added to rice protein glucose-based oral rehydration solutions. An inverse correlation between osmolality and net water absorption was observed (r = -0.653, p less than 0.02). The data suggest that substitution of rice syrup solids for glucose in oral rehydration solutions will

  16. Emergency membrane contactor based absorption system for ammonia leaks in water treatment plants.

    Science.gov (United States)

    Shao, Jiahui; Fang, Xuliang; He, Yiliang; Jin, Qiang

    2008-01-01

    Abstract Because of the suspected health risks of trihalomethanes (THMs), more and more water treatment plants have replaced traditional chlorine disinfection process with chloramines but often without the proper absorption system installed in the case of ammonia leaks in the storage room. A pilot plant membrane absorption system was developed and installed in a water treatment plant for this purpose. Experimentally determined contact angle, surface tension, and corrosion tests indicated that the sulfuric acid was the proper choice as the absorbent for leaking ammonia using polypropylene hollow fiber membrane contactor. Effects of several operating conditions on the mass transfer coefficient, ammonia absorption, and removal efficiency were examined, including the liquid concentration, liquid velocity, and feed gas concentration. Under the operation conditions investigated, the gas absorption efficiency over 99.9% was achieved. This indicated that the designed pilot plant membrane absorption system was effective to absorb the leaking ammonia in the model storage room. The removal rate of the ammonia in the model storage room was also experimentally and theoretically found to be primarily determined by the ammonia suction flow rate from the ammonia storage room to the membrane contactor. The ammonia removal rate of 99.9% was expected to be achieved within 1.3 h at the ammonia gas flow rate of 500 m3/h. The success of the pilot plant membrane absorption system developed in this study illustrated the potential of this technology for ammonia leaks in water treatment plant, also paved the way towards a larger scale application.

  17. Enantiopure distorted ribbon-shaped nanographene combining two-photon absorption-based upconversion and circularly polarized luminescence.

    Science.gov (United States)

    Cruz, Carlos M; Márquez, Irene R; Mariz, Inês F A; Blanco, Victor; Sánchez-Sánchez, Carlos; Sobrado, Jesús M; Martín-Gago, José A; Cuerva, Juan M; Maçôas, Ermelinda; Campaña, Araceli G

    2018-04-28

    Herein we describe a distorted ribbon-shaped nanographene exhibiting unprecedented combination of optical properties in graphene-related materials, namely upconversion based on two-photon absorption (TPA-UC) together with circularly polarized luminescence (CPL). The compound is a graphene molecule of ca. 2 nm length and 1 nm width with edge defects that promote the distortion of the otherwise planar lattice. The edge defects are an aromatic saddle-shaped ketone unit and a [5]carbohelicene moiety. This system is shown to combine two-photon absorption and circularly polarized luminescence and a remarkably long emission lifetime of 21.5 ns. The [5]helicene is responsible for the chiroptical activity while the push-pull geometry and the extended network of sp 2 carbons are factors favoring the nonlinear absorption. Electronic structure theoretical calculations support the interpretation of the results.

  18. The Research on Programmable Control System of Lithium-Bromide Absorption Refrigerating Air Conditioner Based on the Network

    Directory of Open Access Journals (Sweden)

    Sun Lunan

    2016-01-01

    Full Text Available This article regard the solar lithium-bromide absorption refrigerating air conditioning system as the research object, and it was conducting adequate research of the working principle of lithium bromide absorption refrigerating machine, also it was analyzing the requirements of control system about solar energy air conditioning. Then the solar energy air conditioning control system was designed based on PLC, this system was given priority to field bus control system, and the remote monitoring is complementary, which was combining the network remote monitoring technology. So that it realized the automatic control and intelligent control of new lithium bromide absorption refrigerating air conditioning system with solar energy, also, it ensured the control system can automatically detect and adjust when the external conditions was random changing, to make air conditioning work effectively and steadily, ultimately ,it has great research significance to research the air conditioning control system with solar energy.

  19. Short communication: Factors affecting vitamin B12 concentration in milk of commercial dairy herds: An exploratory study.

    Science.gov (United States)

    Duplessis, M; Pellerin, D; Cue, R I; Girard, C L

    2016-06-01

    Only bacteria can synthesize vitamin B12, and this requires adequate Co supply. The natural source of vitamin B12 in human diets comes from animal products, especially those from ruminants. This study aimed to describe variability regarding vitamin B12 concentration in milk among and within commercial dairy herds in early lactation. A secondary objective was to explore potential causes for this variability such as genetic variation and diet characteristics. In total, 399 dairy cows (135 primiparous and 264 multiparous; 386 Holstein and 13 Jersey cows) in 15 commercial herds were involved. Milk samples were taken at 27.4±4.1 and 55.4±4.1d in milk. Neither parity (primiparous vs. multiparous) nor sampling time affected milk concentrations of vitamin B12. Nevertheless, vitamin B12 concentration in milk was highly variable among and within dairy herds. The lowest vitamin B12 concentration in milk of cows was observed in the Jersey herd. Among herds, vitamin B12 concentration in milk ranged from 2,309 to 3,878 pg/mL; one glass (250mL) of milk from those herds would provide between 23 and 40% of the vitamin B12 recommended daily allowance. Among individual cows, however, this provision varied between 16 and 57% of the recommendation. In spite of the limited size of the studied population, the heritability value was 0.23, suggesting that genetic selection could modify milk vitamin B12 concentration. We observed a positive relationship between milk vitamin B12 concentration and dietary acid detergent fiber content and a negative relationship between milk concentration of vitamin B12 and dietary crude protein content. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  20. An Optical Biosensing Strategy Based on Selective Light Absorption and Wavelength Filtering from Chromogenic Reaction

    Directory of Open Access Journals (Sweden)

    Hyeong Jin Chun

    2018-03-01

    Full Text Available To overcome the time and space constraints in disease diagnosis via the biosensing approach, we developed a new signal-transducing strategy that can be applied to colorimetric optical biosensors. Our study is focused on implementation of a signal transduction technology that can directly translate the color intensity signals—that require complicated optical equipment for the analysis—into signals that can be easily counted with the naked eye. Based on the selective light absorption and wavelength-filtering principles, our new optical signaling transducer was built from a common computer monitor and a smartphone. In this signal transducer, the liquid crystal display (LCD panel of the computer monitor served as a light source and a signal guide generator. In addition, the smartphone was used as an optical receiver and signal display. As a biorecognition layer, a transparent and soft material-based biosensing channel was employed generating blue output via a target-specific bienzymatic chromogenic reaction. Using graphics editor software, we displayed the optical signal guide patterns containing multiple polygons (a triangle, circle, pentagon, heptagon, and 3/4 circle, each associated with a specified color ratio on the LCD monitor panel. During observation of signal guide patterns displayed on the LCD monitor panel using a smartphone camera via the target analyte-loaded biosensing channel as a color-filtering layer, the number of observed polygons changed according to the concentration of the target analyte via the spectral correlation between absorbance changes in a solution of the biosensing channel and color emission properties of each type of polygon. By simple counting of the changes in the number of polygons registered by the smartphone camera, we could efficiently measure the concentration of a target analyte in a sample without complicated and expensive optical instruments. In a demonstration test on glucose as a model analyte, we

  1. An Optical Biosensing Strategy Based on Selective Light Absorption and Wavelength Filtering from Chromogenic Reaction.

    Science.gov (United States)

    Chun, Hyeong Jin; Han, Yong Duk; Park, Yoo Min; Kim, Ka Ram; Lee, Seok Jae; Yoon, Hyun C

    2018-03-06

    To overcome the time and space constraints in disease diagnosis via the biosensing approach, we developed a new signal-transducing strategy that can be applied to colorimetric optical biosensors. Our study is focused on implementation of a signal transduction technology that can directly translate the color intensity signals-that require complicated optical equipment for the analysis-into signals that can be easily counted with the naked eye. Based on the selective light absorption and wavelength-filtering principles, our new optical signaling transducer was built from a common computer monitor and a smartphone. In this signal transducer, the liquid crystal display (LCD) panel of the computer monitor served as a light source and a signal guide generator. In addition, the smartphone was used as an optical receiver and signal display. As a biorecognition layer, a transparent and soft material-based biosensing channel was employed generating blue output via a target-specific bienzymatic chromogenic reaction. Using graphics editor software, we displayed the optical signal guide patterns containing multiple polygons (a triangle, circle, pentagon, heptagon, and 3/4 circle, each associated with a specified color ratio) on the LCD monitor panel. During observation of signal guide patterns displayed on the LCD monitor panel using a smartphone camera via the target analyte-loaded biosensing channel as a color-filtering layer, the number of observed polygons changed according to the concentration of the target analyte via the spectral correlation between absorbance changes in a solution of the biosensing channel and color emission properties of each type of polygon. By simple counting of the changes in the number of polygons registered by the smartphone camera, we could efficiently measure the concentration of a target analyte in a sample without complicated and expensive optical instruments. In a demonstration test on glucose as a model analyte, we could easily measure the

  2. Vitamin B12 in metformin-treated diabetic patients: a cross-sectional study in Brazil Vitamina B12 em pacientes diabéticos usando metformina: um corte transversal no Brasil

    Directory of Open Access Journals (Sweden)

    Monique Nervo

    2011-02-01

    Full Text Available OBJECTIVE: The objective of this study was to evaluate the presence of vitamin B12 deficiency and the factors associated with serum vitamin B12 levels in a sample of metformin-treated Brazilian diabetic patients. METHOD: Cross-sectional study. RESULTS: 144 patients were included. Serum vitamin B12 levels were low (OBJETIVO: O objetivo deste estudo foi avaliar a prevalência de deficiência de vitamina B12 em pacientes diabéticos brasileiros tratados com metformina e os fatores associados aos níveis séricos de vitamina B12. MÉTODO: Corte transversal. RESULTADOS: 144 pacientes foram incluídos. Os níveis séricos de vitamina B12 foram baixos (< 125 pmol/L em 10 pacientes (6,9% e possivelmente baixos (125 - 250pmol/L em 53 pacientes (36,8%. Os níveis séricos de vitamina B12 foram associados negativamente à idade (B = -3,17; β = -0,171; p = 0,037 e à duração do uso de metformina (B = -33,36; β= -0,161; p = 0,048 e positivamente com a ingestão estimada de vitamina B12 (B = 67,96; β = 0,249; p = 0,002. CONCLUSÃO: Estes resultados sugerem alta prevalência de deficiência de vitamina B12 em pacientes diabéticos tratados com metformina. Pacientes mais velhos, em uso de metformina há muito tempo e com ingestão baixa de vitamina B12 estão provavelmente mais predispostos a essa deficiência.

  3. Genetic and non-genetic influences during pregnancy on infant global and site specific DNA methylation: role for folate gene variants and vitamin B12.

    Directory of Open Access Journals (Sweden)

    Jill A McKay

    Full Text Available Inter-individual variation in patterns of DNA methylation at birth can be explained by the influence of environmental, genetic and stochastic factors. This study investigates the genetic and non-genetic determinants of variation in DNA methylation in human infants. Given its central role in provision of methyl groups for DNA methylation, this study focuses on aspects of folate metabolism. Global (LUMA and gene specific (IGF2, ZNT5, IGFBP3 DNA methylation were quantified in 430 infants by Pyrosequencing®. Seven polymorphisms in 6 genes (MTHFR, MTRR, FOLH1, CβS, RFC1, SHMT involved in folate absorption and metabolism were analysed in DNA from both infants and mothers. Red blood cell folate and serum vitamin B(12 concentrations were measured as indices of vitamin status. Relationships between DNA methylation patterns and several covariates viz. sex, gestation length, maternal and infant red cell folate, maternal and infant serum vitamin B(12, maternal age, smoking and genotype were tested. Length of gestation correlated positively with IGF2 methylation (rho = 0.11, p = 0.032 and inversely with ZNT5 methylation (rho = -0.13, p = 0.017. Methylation of the IGFBP3 locus correlated inversely with infant vitamin B(12 concentration (rho = -0.16, p = 0.007, whilst global DNA methylation correlated inversely with maternal vitamin B(12 concentrations (rho = 0.18, p = 0.044. Analysis of common genetic variants in folate pathway genes highlighted several associations including infant MTRR 66G>A genotype with DNA methylation (χ(2 = 8.82, p = 0.003 and maternal MTHFR 677C>T genotype with IGF2 methylation (χ(2 = 2.77, p = 0.006. These data support the hypothesis that both environmental and genetic factors involved in one-carbon metabolism influence DNA methylation in infants. Specifically, the findings highlight the importance of vitamin B(12 status, infant MTRR genotype and maternal MTHFR genotype, all of which may influence the supply of methyl groups for

  4. Acquired thermotolerance and heat shock in the extremely thermophilic archaebacterium Sulfolobus sp. strain B12.

    OpenAIRE

    Trent, J D; Osipiuk, J; Pinkau, T

    1990-01-01

    The extreme thermophile Sulfolobus sp. strain B12 exhibits an acquired thermotolerance response. Thus, survival of cells from a 70 degrees C culture at the lethal temperature of 92 degrees C was enhanced by as much as 6 orders of magnitude over a 2-h period if the culture was preheated to 88 degrees C for 60 min or longer before being exposed to the lethal temperature. In eubacteria and eucaryotes, acquired thermotolerance correlates with the induced synthesis of a dozen or so proteins known ...

  5. Ultrasonographic evaluation to diagnose hepatic lipidosis in Egyptian Zaraibi goats with vitamin B12 deficiency

    OpenAIRE

    Sabry A. El-Khodery; Hussein S. Hussein; Mohamed E. El-Boshy; Medhat N. Nassif

    2011-01-01

    As little is known about the ultrasonographic features of hepatic lipidosis (white liver disease) in goats, this study was undertaken to evaluate the use of ultrasound for the diagnosis of hepatic lipidosis associated with vitamin B12 (cyanocobalamin) deficiency in Egyptian Zaraibi goats. A total of 38 goats (28 with weight loss, diarrhoea and anaemia and 10 clinically healthy) were studied. Twenty-one goats were demonstrated to have cobalt and cyanocobalamin deficiency (0.33 ± 0.12 μmol/l an...

  6. Blood homocysteine, folic acid, vitamin B12 and vitamin B6 levels in psoriasis patients

    Directory of Open Access Journals (Sweden)

    Meltem Uslu

    2017-09-01

    Full Text Available Background and Design: Homocysteine, a sulfur-containing amino acid, is known to be related with autoimmunity-inflammation, cardiovascular disease and DNA methylation. In this case-control study, we aimed to determine plasma homocysteine, folic acid, vitamin B12 and vitamin B6 levels in patients with psoriasis. Materials and Methods: Smoking, alcohol and coffee consumption habits were recorded in adult patients with plaque-type psoriasis and age- and sex-matched controls. Height and weight measurements were performed and Psoriasis Area and Severity Index (PASI scores were calculated. Fasting venous blood samples were collected to determine homocysteine, folic acid, vitamin B12, vitamin B6, glucose, total cholesterol, triglyceride, high density lipoprotein (HDL, erythrocyte sedimentation rate (ESR, and C-reactive protein (CRP levels. Results: There was no significant difference between psoriasis patients (n=43 and controls (n=47 in body mass index and alcohol and coffee consumption. Smoking rate was significantly high in psoriasis patients. The median PASI score was 10.0 (8.3-12.8. Plasma homocysteine, folic acid, vitamin B12, vitamin B6, total cholesterol, triglyseride, ESR and CRP values were not significantly different between patients and the controls. HDL level was low in psoriasis patients (p=0.001. Plasma homocysteine level was higher in males than in females. There was no relationship of homocysteine levels with patient’s age, PASI scores, ESR, CRP values and lipids. Homocysteine levels were inversely related with folic acid and vitamin B12 (p=0.000, r=-0.436, p=0.047, r=-0.204, respectively. We did not find any relationship between homocysteine and vitamin B6 levels. Conclusion: There was no increase in plasma homocysteine levels in psoriasis patients we followed up. Homocysteine level increases in inflammatory disorders and this increase is accepted as a cardiovascular disease marker. Homocysteine homeostasis may be balanced in our

  7. Expeditious Synthesis of Noble Metal Nanoparticles Using Vitamin B12 under Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Changseok Han

    2015-08-01

    Full Text Available A greener synthesis protocol for noble nanometals is developed using vitamin B12 as a reducing and capping agent in conjunction with the use of microwaves. Successful assembly of nanoparticles or microparticles with varied shapes and sizes have been demonstrated. The synthesized Ag, Au, and Pd samples were thoroughly characterized with X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high resolution transmission microscopy, and UV-visible spectrophotometry, confirming that metallic Ag, Au, and Pd were synthesized by the green chemistry method.

  8. Rapid microbiological assay of serum vitamin B 12 by electronic counter.

    Science.gov (United States)

    Stuart, J; Sklaroff, S A

    1966-01-01

    A new method of measuring the growth of Lactobacillus leichmannii is reported. Its adoption for the estimation of serum vitamin B(12) levels shortens the incubation period required to five hours at 45 degrees C. The method is compared statistically with a standard method of estimation, requiring incubation at 37 degrees C., by duplicate determinations on 106 hospital patients. The significance of the apparently decreased accuracy of the new method at low serum levels is discussed, and a re-appraisal of the optimum growth temperature of Lactobacillus leichmannii suggested.

  9. Polarized-neutron study of spin dynamics in the Kondo insulator YbB12.

    Science.gov (United States)

    Nemkovski, K S; Mignot, J-M; Alekseev, P A; Ivanov, A S; Nefeodova, E V; Rybina, A V; Regnault, L-P; Iga, F; Takabatake, T

    2007-09-28

    Inelastic neutron scattering experiments have been performed on the archetype compound YbB(12), using neutron polarization analysis to separate the magnetic signal from the phonon background. With decreasing temperature, components characteristic for a single-site spin-fluctuation dynamics are suppressed, giving place to specific, strongly Q-dependent, low-energy excitations near the spin-gap edge. This crossover is discussed in terms of a simple crystal-field description of the incoherent high-temperature state and a predominantly local mechanism for the formation of the low-temperature singlet ground state.

  10. High-level folate production in fermented foods by the B12 producer Lactobacillus reuteri JCM1112

    NARCIS (Netherlands)

    Santos, F.; Wegkamp, A.; de Vos, W.M.; Smid, E.J.; Hugenholtz, J.

    2008-01-01

    We observed that Lactobacillus reuteri JCM1112 produces B12 and folate. However, the folate/B12 mass ratio found was far below that desired for human consumption (~170:1). We used metabolic engineering applying genetic and physiological approaches to improve this ratio and developed a generic and

  11. Optimization of folic acid, vitamin B-12, and vitamin B-6 supplements in pediatric patients with sickle cell disease

    NARCIS (Netherlands)

    van der Dijs, Fey P L; Fokkema, M Rebecca; Dijck-Brouwer, D A Janneke; Niessink, Bram; van der Wal, Thaliet I C; Schnog, John-John B; Duits, Ashley J; Muskiet, Fred D; Muskiet, Frits A J

    Using homocysteine as a functional marker, we determined optimal folic acid, vitamin B-12, and vitamin B-6 dosages in 21 pediatric sickle cell disease (SCD) patients (11 HbSS, 10 HbSC; 7-16 years). Daily supplements of folic acid (400, 700, or 1,000 mug), vitamin B-12 (1, 3, or 5 U.S. 1989 RDA), and

  12. Effect of vitamin B12 pulse addition on the performance of cobalt deprived anaerobic granular sludge bioreactors

    KAUST Repository

    Fermoso, Fernando G.; Bartacek, Jan; Lens, Piet N.L.

    2010-01-01

    The effect of a pulse addition of vitamin B12 as cobalt source to restore the performance of cobalt depleted methanol-fed bioreactors was investigated. One upflow anaerobic sludge bed (UASB) reactor was supplied with a pulse of vitamin B12, and its

  13. Vitamin B-12 deficiency and the lack of its consequences in type 2 diabetes patients using metformin

    NARCIS (Netherlands)

    de Groot-Kamphuis, D. M.; van Dijk, P. R.; Groenier, K. H.; Houweling, Sebastiaan; Bilo, H. J. G.; Kleefstra, N.

    Objectives: To study vitamin B-12 concentrations in patients with type 2 diabetes with and without metformin use and to identify risk factors and consequences of low vitamin B-12 concentrations. Research design and methods: This study had a cross-sectional design. During eight weeks all patients

  14. Vitamin B12 deficiency and the lack of its consequences in type 2 diabetes patients using metformin

    NARCIS (Netherlands)

    de Groot-Kamphuis, D M; van Dijk, P R; Groenier, K H; Houweling, S T; Bilo, H J G; Kleefstra, N

    OBJECTIVES: To study vitamin B12 concentrations in patients with type 2 diabetes with and without metformin use and to identify risk factors and consequences of low vitamin B12 concentrations. RESEARCH DESIGN AND METHODS: This study had a cross-sectional design. During eight weeks all patients with

  15. Associations of genetic determinants of serum vitamin B12 and folate concentrations with hay fever and asthma

    DEFF Research Database (Denmark)

    Skaaby, Tea; Taylor, Amy E; Jacobsen, Rikke K

    2017-01-01

    Background/objectives: Studies of the effect of vitamin B12 and folate on the risk of asthma and hay fever have shown inconsistent results that may be biased by reverse causation and confounding. We used a Mendelian randomization approach to examine a potential causal effect of vitamin B12 and fo...

  16. Laser frequency locking based on the normal and abnormal saturated absorption spectroscopy of 87Rb

    International Nuclear Information System (INIS)

    Wan Jian-Hong; Liu Chang; Wang Yan-Hui

    2016-01-01

    We present a practical method to avoid the mis-locking phenomenon in the saturated-absorption-spectrum laser-frequency-locking system and set up a simple theoretical model to explain the abnormal saturated absorption spectrum. The method uses the normal and abnormal saturated absorption spectra of the same transition 5 2 S 1/2 , F = 2–5 2 P 3/2 , F′ = 3 saturated absorption of the 87 Rb D 2 resonance line. After subtracting these two signals with the help of electronics, we can obtain a spectrum with a single peak to lock the laser. In our experiment, we use the normal and inverse signals of the transitions 5 2 S 1/2 , F = 2–5 2 P 3/2 , F′ = 3 saturated absorption of the 87 Rb D 2 resonance line to lock a 780-nm distributed feedback (DFB) diode laser. This method improves the long-term locking performance and is suitable for other kinds of diode lasers. (paper)

  17. Satellite-based evidence of wavelength-dependent aerosol absorption in biomass burning smoke inferred from Ozone Monitoring Instrument

    Directory of Open Access Journals (Sweden)

    H. Jethva

    2011-10-01

    Full Text Available We provide satellite-based evidence of the spectral dependence of absorption in biomass burning aerosols over South America using near-UV measurements made by the Ozone Monitoring Instrument (OMI during 2005–2007. In the current near-UV OMI aerosol algorithm (OMAERUV, it is implicitly assumed that the only absorbing component in carbonaceous aerosols is black carbon whose imaginary component of the refractive index is wavelength independent. With this assumption, OMI-derived aerosol optical depth (AOD is found to be significantly over-estimated compared to that of AERONET at several sites during intense biomass burning events (August-September. Other well-known sources of error affecting the near-UV method of aerosol retrieval do not explain the large observed AOD discrepancies between the satellite and the ground-based observations. A number of studies have revealed strong spectral dependence in carbonaceous aerosol absorption in the near-UV region suggesting the presence of organic carbon in biomass burning generated aerosols. A sensitivity analysis examining the importance of accounting for the presence of wavelength-dependent aerosol absorption in carbonaceous particles in satellite-based remote sensing was carried out in this work. The results convincingly show that the inclusion of spectrally-dependent aerosol absorption in the radiative transfer calculations leads to a more accurate characterization of the atmospheric load of carbonaceous aerosols. The use of a new set of aerosol models assuming wavelength-dependent aerosol absorption in the near-UV region (Absorption Angstrom Exponent λ−2.5 to −3.0 improved the OMAERUV retrieval results by significantly reducing the AOD bias observed when gray aerosols were assumed. In addition, the new retrieval of single-scattering albedo is in better agreement with those of AERONET within the uncertainties (ΔSSA = ±0.03. The new colored carbonaceous aerosol model was also found to

  18. Diode-laser-based water vapor differential absorption lidar (DIAL) profiler evaluation

    Science.gov (United States)

    Spuler, S.; Weckwerth, T.; Repasky, K. S.; Nehrir, A. R.; Carbone, R.

    2012-12-01

    We are in the process of evaluating the performance of an eye-safe, low-cost, diode-laser-based, water vapor differential absorption lidar (DIAL) profiler. This class of instrument may be capable of providing continuous water vapor and aerosol backscatter profiles at high vertical resolution in the atmospheric boundary layer (ABL) for periods of months to years. The technology potentially fills a national long term observing facility gap and could greatly benefit micro- and meso-meteorology, water cycle, carbon cycle and, more generally, biosphere-hydrosphere-atmosphere interaction research at both weather and climate variability time scales. For the evaluation, the Montana State University 3rd generation water vapor DIAL was modified to enable unattended operation for a period of several weeks. The performance of this V3.5 version DIAL was tested at MSU and NCAR in June and July of 2012. Further tests are currently in progress with Howard University at Beltsville, Maryland; and with the National Weather Service and Oklahoma University at Dallas/Fort Worth, Texas. The presentation will include a comparison of DIAL profiles against meteorological "truth" at the aforementioned locations including: radiosondes, Raman lidars, microwave and IR radiometers, AERONET and SUOMINET systems. Instrument reliability, uncertainty, systematic biases, detection height statistics, and environmental complications will be evaluated. Performance will be judged in the context of diverse scientific applications that range from operational weather prediction and seasonal climate variability, to more demanding climate system process studies at the land-canopy-ABL interface. Estimating the extent to which such research and operational applications can be satisfied with a low cost autonomous network of similar instruments is our principal objective.

  19. Estimating Snow Water Equivalent with Backscattering at X and Ku Band Based on Absorption Loss

    Directory of Open Access Journals (Sweden)

    Yurong Cui

    2016-06-01

    Full Text Available Snow water equivalent (SWE is a key parameter in the Earth’s energy budget and water cycle. It has been demonstrated that SWE can be retrieved using active microwave remote sensing from space. This necessitates the development of forward models that are capable of simulating the interactions of microwaves and the snow medium. Several proposed models have described snow as a collection of sphere- or ellipsoid-shaped ice particles embedded in air, while the microstructure of snow is, in reality, more complex. Natural snow usually forms a sintered structure following mechanical and thermal metamorphism processes. In this research, the bi-continuous vector radiative transfer (bi-continuous-VRT model, which firstly constructs snow microstructure more similar to real snow and then simulates the snow backscattering signal, is used as the forward model for SWE estimation. Based on this forward model, a parameterization scheme of snow volume backscattering is proposed. A relationship between snow optical thickness and single scattering albedo at X and Ku bands is established by analyzing the database generated from the bi-continuous-VRT model. A cost function with constraints is used to solve effective albedo and optical thickness, while the absorption part of optical thickness is obtained from these two parameters. SWE is estimated after a correction for physical temperature. The estimated SWE is correlated with the measured SWE with an acceptable accuracy. Validation against two-year measurements, using the SnowScat instrument from the Nordic Snow Radar Experiment (NoSREx, shows that the estimated SWE using the presented algorithm has a root mean square error (RMSE of 16.59 mm for the winter of 2009–2010 and 19.70 mm for the winter of 2010–2011.

  20. New waste heat district heating system with combined heat and power based on absorption heat exchange cycle in China

    International Nuclear Information System (INIS)

    Sun Fangtian; Fu Lin; Zhang Shigang; Sun Jian

    2012-01-01

    A new waste heat district heating system with combined heat and power based on absorption heat exchange cycle (DHAC) was developed to increase the heating capacity of combined heat and power (CHP) through waste heat recovery, and enhance heat transmission capacity of the existing primary side district heating network through decreasing return water temperature by new type absorption heat exchanger (AHE). The DHAC system and a conventional district heating system based on CHP (CDH) were analyzed in terms of both thermodynamics and economics. Compared to CDH, the DHAC increased heating capacity by 31% and increased heat transmission capacity of the existing primary side district heating network by 75%. The results showed that the exergetic efficiency of DHAC was 10.41% higher and the product exergy monetary cost was 36.6¥/GJ less than a CHD. DHAC is an effective way to increase thermal utilization factor of CHP, and to reduce district heating cost. - Highlights: ► Absorption heat pumps are used to recover waste heat in CHP. ► Absorption heat exchanger can reduce exergy loss in the heat transfer process. ► New waste heat heating system (DHAC) can increase heating capacity of CHP by 31%. ► DHAC can enhance heat transmission capacity of the primary pipe network by 75%. ► DHAC system has the higher exergetic efficiency and the better economic benefit.

  1. Elevated plasma vitamin B12 levels and cancer prognosis: A population-based cohort study

    DEFF Research Database (Denmark)

    Arendt, Johan Frederik Håkonsen; Farkas, Dora Kormendine; Pedersen, Lars

    2015-01-01

    patients without a plasma Cbl measurement. Patients treated with Cbl were excluded. Survival probability was assessed using Kaplan-Meier curves. Mortality risk ratios (MRR) were computed using Cox proportional hazard regression, adjusted for age, sex, calendar year, cancer stage and comorbidity, scored...

  2. Probing Reversible Chemistry in Coenzyme B12-Dependent Ethanolamine Ammonia Lyase with Kinetic Isotope Effects

    Science.gov (United States)

    Jones, Alex R; Rentergent, Julius; Scrutton, Nigel S; Hay, Sam

    2015-01-01

    Coenzyme B12-dependent enzymes such as ethanolamine ammonia lyase have remarkable catalytic power and some unique properties that enable detailed analysis of the reaction chemistry and associated dynamics. By selectively deuterating the substrate (ethanolamine) and/or the β-carbon of the 5′-deoxyadenosyl moiety of the intrinsic coenzyme B12, it was possible to experimentally probe both the forward and reverse hydrogen atom transfers between the 5′-deoxyadenosyl radical and substrate during single-turnover stopped-flow measurements. These data are interpreted within the context of a kinetic model where the 5′-deoxyadenosyl radical intermediate may be quasi-stable and rearrangement of the substrate radical is essentially irreversible. Global fitting of these data allows estimation of the intrinsic rate constants associated with CoC homolysis and initial H-abstraction steps. In contrast to previous stopped-flow studies, the apparent kinetic isotope effects are found to be relatively small. PMID:25950663

  3. Fast and effective transformation of toxaphene by superreduced vitamin B12 and dicyanocobalamin

    Energy Technology Data Exchange (ETDEWEB)

    Recke, R. von der; Gaul, S. [Inst. of Food Chemistry, Univ. of Hohenheim, Stuttgart (Germany); Ruppe, S.; Vetter, W. [Inst. of Food and Nutrition, Friedrich-Schiller-Univ. Jena (Germany); Neumann, A. [Dept. of Technical Biology, Univ. of Karlsruhe (Germany)

    2004-09-15

    The chloropesticide toxaphene (Camphechlor, Melipax) has been used in high quantities since 1945. Toxaphene has been classified as a persistent organohalogen pollutant (POP) and belongs to the ''dirty dozen''. Due to its heavy use in the 1960s and 1970s, several environmental compartments were significantly contaminated with toxaphene. For instance, concentrations in polluted areas could exceed 1 mg/kg sediment. Recently, it was shown that cultures of the isolated bacterium Dehalospirillum multivorans transformed toxaphene in a similar way as anaerobic sediment and soil samples. The potential of D. multivorans for the anaerobic transformation of organohalogens was previously demonstrated for chloroethenes (PCE and TCE) 6. The reactive dehalogenase of D. multivorans contains a corrinoide co-factor. In this study two corrinoids cyanocobalamin (vitamin B12, CCA) and dicyanocobinamide (DCC) were used in their superreduced forms (i. e. those having the central atom Co in the oxidation state +I). Interestingly, a very fast transformation of toxaphene was observed with superreduced DCC. Unfortunately, the transformation occurred so fast that no transformation products could be identified. For this reason, we performed further experiments with the less reactive superreduced vitamin B12 (CCA{sub s}). CCA{sub s} has previously been used for the transformation of PCBs, hexachlorobenzene, chloroform, and chloroethanes.

  4. Physiological role of vitamin B12 in a methanol-utilizing bacterium, Protaminobacter ruber

    International Nuclear Information System (INIS)

    Shimizu, S.; Ueda, S.; Sato, K.

    1984-01-01

    The methanol-utilizing bacterium Protaminobacter ruber is able to produce a relatively large amount of vitamin B 12 . The present study aims at the physiological role of vitamin B 12 in P. ruber. P. ruber was found to contain the two sequential reactions of glutamate mutase with β-methylaspartase and propionyl-CoA carboxylase with methylmalonyl-CoA mutase. Considering the presence of these enzyme systems and the reaction from mesaconyl-CoA to glyoxylate and propionyl-CoA, it could be considered that the formation of glutamate from α-ketoglutarate, the conversion of glutamate to mesaconate via β-methylaspartate, the activation of mesaconate with CoA to form mesaconyl-CoA, the cleavage of mesaconyl-CoA to glyoxylate and propionyl-CoA, the carboxylation of propionyl-CoA to methylmalonyl-CoA, and the isomerization of methylmalonyl-CoA to succinyl-CoA require cobalamine as a cofactor. 29 refs., 2 figs., 2 tabs

  5. Conformational cycle of the vitamin B12 ABC importer in liposomes detected by double electron-electron resonance (DEER).

    Science.gov (United States)

    Joseph, Benesh; Korkhov, Vladimir M; Yulikov, Maxim; Jeschke, Gunnar; Bordignon, Enrica

    2014-02-07

    Double electron-electron resonance is used here to investigate intermediates of the transport cycle of the Escherichia coli vitamin B12 ATP-binding cassette importer BtuCD-F. Previously, we showed the ATP-induced opening of the cytoplasmic gate I in TM5 helices, later confirmed by the AMP-PNP-bound BtuCD-F crystal structure. Here, other key residues are analyzed in TM10 helices (positions 307 and 322) and in the cytoplasmic gate II, i.e. the loop between TM2 and TM3 (positions 82 and 85). Without BtuF, binding of ATP induces detectable changes at positions 307 and 85 in BtuCD in liposomes. Together with BtuF, ATP triggers the closure of the cytoplasmic gate II in liposomes (reported by both positions 82 and 85). This forms a sealed cavity in the translocation channel in agreement with the AMP-PNP·BtuCD-F x-ray structure. When vitamin B12 and AMP-PNP are simultaneously present, the extent of complex formation is reduced, but the short 82-82 interspin distance detected indicates that the substrate does not affect the closed conformation of this gate. The existence of the BtuCD-F complex under these conditions is verified with spectroscopically orthogonal nitroxide and Gd(III)-based labels. The cytoplasmic gate II remains closed also in the vanadate-trapped state, but it reopens in the ADP-bound state of the complex. Therefore, we suggest that the substrate likely trapped in ATP·BtuCD-F can be released after ATP hydrolysis but before the occluded ADP-bound conformation is reached.

  6. Enhanced high-frequency microwave absorption of Fe3O4 architectures based on porous nanoflake

    DEFF Research Database (Denmark)

    Wang, Xiaoliang; Liu, Yanguo; Han, Hongyan

    2017-01-01

    Hierarchical Fe3O4 architectures assembled with porous nanoplates (p-Fe3O4) were synthesized. Due to the strong shape anisotropy of the nanoplates, the p-Fe3O4 exhibits increased microwave resonance towards high frequency range. The improved microwave absorption properties of the p-Fe3O4, includi...

  7. Enhanced high-frequency microwave absorption of Fe3O4 architectures based on porous nanoflake

    DEFF Research Database (Denmark)

    Wang, Xiaoliang; Liu, Yanguo; Han, Hongyan

    2017-01-01

    Hierarchical Fe3O4 architectures assembled with porous nanoplates (p-Fe3O4) were synthesized. Due to the strong shape anisotropy of the nanoplates, the p-Fe3O4 exhibits increased microwave resonance towards high frequency range. The improved microwave absorption properties of the p-Fe3O4, including...

  8. Moisture movement in cement-based repair systems monitored by X-ray absorption

    NARCIS (Netherlands)

    Lukovic, M.; Ye, G.; Schlangen, H.E.J.G.; van Breugel, K.

    2017-01-01

    In concrete repair systems, material properties in the repair material and interface are greatly influenced by the initial moisture content of the concrete (or mortar) substrate. In order to quantify moisture profiles inside the repair system, X-ray absorption was used. Preliminary studies are

  9. Self-assembly based plasmonic arrays tuned by atomic layer deposition for extreme visible light absorption.

    Science.gov (United States)

    Hägglund, Carl; Zeltzer, Gabriel; Ruiz, Ricardo; Thomann, Isabell; Lee, Han-Bo-Ram; Brongersma, Mark L; Bent, Stacey F

    2013-07-10

    Achieving complete absorption of visible light with a minimal amount of material is highly desirable for many applications, including solar energy conversion to fuel and electricity, where benefits in conversion efficiency and economy can be obtained. On a fundamental level, it is of great interest to explore whether the ultimate limits in light absorption per unit volume can be achieved by capitalizing on the advances in metamaterial science and nanosynthesis. Here, we combine block copolymer lithography and atomic layer deposition to tune the effective optical properties of a plasmonic array at the atomic scale. Critical coupling to the resulting nanocomposite layer is accomplished through guidance by a simple analytical model and measurements by spectroscopic ellipsometry. Thereby, a maximized absorption of light exceeding 99% is accomplished, of which up to about 93% occurs in a volume-equivalent thickness of gold of only 1.6 nm. This corresponds to a record effective absorption coefficient of 1.7 × 10(7) cm(-1) in the visible region, far exceeding those of solid metals, graphene, dye monolayers, and thin film solar cell materials. It is more than a factor of 2 higher than that previously obtained using a critically coupled dye J-aggregate, with a peak width exceeding the latter by 1 order of magnitude. These results thereby substantially push the limits for light harvesting in ultrathin, nanoengineered systems.

  10. Resonant Absorption in GaAs-Based Nanowires by Means of Photo-Acoustic Spectroscopy

    Science.gov (United States)

    Petronijevic, E.; Leahu, G.; Belardini, A.; Centini, M.; Li Voti, R.; Hakkarainen, T.; Koivusalo, E.; Guina, M.; Sibilia, C.

    2018-03-01

    Semiconductor nanowires made of high refractive index materials can couple the incoming light to specific waveguide modes that offer resonant absorption enhancement under the bandgap wavelength, essential for light harvesting, lasing and detection applications. Moreover, the non-trivial ellipticity of such modes can offer near field interactions with chiral molecules, governed by near chiral field. These modes are therefore very important to detect. Here, we present the photo-acoustic spectroscopy as a low-cost, reliable, sensitive and scattering-free tool to measure the spectral position and absorption efficiency of these modes. The investigated samples are hexagonal nanowires with GaAs core; the fabrication by means of lithography-free molecular beam epitaxy provides controllable and uniform dimensions that allow for the excitation of the fundamental resonant mode around 800 nm. We show that the modulation frequency increase leads to the discrimination of the resonant mode absorption from the overall absorption of the substrate. As the experimental data are in great agreement with numerical simulations, the design can be optimized and followed by photo-acoustic characterization for a specific application.

  11. Analysis of Different Methods for Wave Generation and Absorption in a CFD-Based Numerical Wave Tank

    Directory of Open Access Journals (Sweden)

    Adria Moreno Miquel

    2018-06-01

    Full Text Available In this paper, the performance of different wave generation and absorption methods in computational fluid dynamics (CFD-based numerical wave tanks (NWTs is analyzed. The open-source CFD code REEF3D is used, which solves the Reynolds-averaged Navier–Stokes (RANS equations to simulate two-phase flow problems. The water surface is computed with the level set method (LSM, and turbulence is modeled with the k-ω model. The NWT includes different methods to generate and absorb waves: the relaxation method, the Dirichlet-type method and active wave absorption. A sensitivity analysis has been conducted in order to quantify and compare the differences in terms of absorption quality between these methods. A reflection analysis based on an arbitrary number of wave gauges has been adopted to conduct the study. Tests include reflection analysis of linear, second- and fifth-order Stokes waves, solitary waves, cnoidal waves and irregular waves generated in an NWT. Wave breaking over a sloping bed and wave forces on a vertical cylinder are calculated, and the influence of the reflections on the wave breaking location and the wave forces on the cylinder is investigated. In addition, a comparison with another open-source CFD code, OpenFOAM, has been carried out based on published results. Some differences in the calculated quantities depending on the wave generation and absorption method have been observed. The active wave absorption method is seen to be more efficient for long waves, whereas the relaxation method performs better for shorter waves. The relaxation method-based numerical beach generally results in lower reflected waves in the wave tank for most of the cases simulated in this study. The comparably better performance of the relaxation method comes at the cost of larger computational requirements due to the relaxation zones that have to be included in the domain. The reflections in the NWT in REEF3D are generally lower than the published results for

  12. GIS based approach for atmospheric carbon absorption strategies through forests development in Indian situations

    International Nuclear Information System (INIS)

    Yadav, Surendra Kumar

    2013-01-01

    Geographical information system (GIS) play important role in forest management. An effective strategy for enhancement of atmospheric carbon absorption productivity is through forests development in degraded forest areas and waste lands. Forestry sector has significant emissions removal capability which can further be enhanced by operationalizing major afforestation and reforestation initiatives like National Mission for a Green India besides continued strengthening of the present protection regime of forests. Secondary data was collected and analyzed. Different types of waste lands require different strategies for their development into forest areas; but few waste lands like rocky regions, glacier regions etc. cannot be developed into forest areas. Atmospheric carbon management is major problem before world community in present circumstances to control environmental pollution. Various forest ecosystems play significant role in carbon absorption. The diffusional net absorption rate of anthropogenic carbon to the biosphere is some unknown function of the atmospheric partial pressure of carbon dioxide. Estimations reveal that the average carbon absorption of the forests was around 1,240 grams (1.240 Kg) of carbon per square meter of canopy area. To stabilize atmospheric CO 2 , role of forestry depends on harvesting and disturbance rates, expectations of future forest productivity, and the ability to deploy technology and forest practices to increase the retention of sequestered CO 2 . There is a considerable self-damping effect that will moderate the future increase of the atmospheric carbon dioxide concentration. Capacity of the ocean to absorb carbon dioxide is limited; but atmospheric carbon absorption potentiality of India forests can be increased tremendously through reforestation, afforestation and development of degraded forest areas and waste lands. About 60 % of Indian waste lands can be developed to increase forest cover with reasonable efforts. When

  13. GIS based approach for atmospheric carbon absorption strategies through forests development in Indian situations

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Surendra Kumar [CCS Univ., Meerut (India). SCRIET

    2013-07-01

    Geographical information system (GIS) play important role in forest management. An effective strategy for enhancement of atmospheric carbon absorption productivity is through forests development in degraded forest areas and waste lands. Forestry sector has significant emissions removal capability which can further be enhanced by operationalizing major afforestation and reforestation initiatives like National Mission for a Green India besides continued strengthening of the present protection regime of forests. Secondary data was collected and analyzed. Different types of waste lands require different strategies for their development into forest areas; but few waste lands like rocky regions, glacier regions etc. cannot be developed into forest areas. Atmospheric carbon management is major problem before world community in present circumstances to control environmental pollution. Various forest ecosystems play significant role in carbon absorption. The diffusional net absorption rate of anthropogenic carbon to the biosphere is some unknown function of the atmospheric partial pressure of carbon dioxide. Estimations reveal that the average carbon absorption of the forests was around 1,240 grams (1.240 Kg) of carbon per square meter of canopy area. To stabilize atmospheric CO{sub 2}, role of forestry depends on harvesting and disturbance rates, expectations of future forest productivity, and the ability to deploy technology and forest practices to increase the retention of sequestered CO{sub 2}. There is a considerable self-damping effect that will moderate the future increase of the atmospheric carbon dioxide concentration. Capacity of the ocean to absorb carbon dioxide is limited; but atmospheric carbon absorption potentiality of India forests can be increased tremendously through reforestation, afforestation and development of degraded forest areas and waste lands. About 60 % of Indian waste lands can be developed to increase forest cover with reasonable efforts. When

  14. NutriPhone: a mobile platform for low-cost point-of-care quantification of vitamin B12 concentrations.

    Science.gov (United States)

    Lee, Seoho; O'Dell, Dakota; Hohenstein, Jess; Colt, Susannah; Mehta, Saurabh; Erickson, David

    2016-06-15

    Vitamin B12 is necessary for formation of red blood cells, DNA synthesis, neural myelination, brain development, and growth. Vitamin B12 deficiency is often asymptomatic early in its course; however, once it manifests, particularly with neurological symptoms, reversal by dietary changes or supplementation becomes less effective. Access to easy, low cost, and personalized nutritional diagnostics could enable individuals to better understand their own deficiencies as well as track the effects of dietary changes. In this work, we present the NutriPhone, a mobile platform for the analysis of blood vitamin B12 levels in 15 minutes. The NutriPhone technology comprises of a smartphone accessory, an app, and a competitive-type lateral flow test strip that quantifies vitamin B12 levels. To achieve the detection of sub-nmol/L physiological levels of vitamin B12, our assay incorporates an innovative "spacer pad" for increasing the duration of the key competitive binding reaction and uses silver amplification of the initial signal. We demonstrate the efficacy of our NutriPhone system by quantifying physiologically relevant levels of vitamin B12 and performing human trials where it was used to accurately evaluate blood vitamin B12 status of 12 participants from just a drop (~40 μl) of finger prick blood.

  15. Vitamin B12 and folate during pregnancy and offspring motor, mental and social development at 2 years of age.

    Science.gov (United States)

    Bhate, V K; Joshi, S M; Ladkat, R S; Deshmukh, U S; Lubree, H G; Katre, P A; Bhat, D S; Rush, E C; Yajnik, C S

    2012-04-01

    Insufficiency of vitamin B12 (B12) and folate during pregnancy can result in low concentrations in the fetus and have adverse effects on brain development. We investigated the relationship between maternal B12 and folate nutrition during pregnancy and offspring motor, mental and social development at two years of age (2 y). Mothers (n = 123) and their offspring (62 girls, 61 boys) from rural and middle-class urban communities in and around Pune city were followed through pregnancy up to 2 y. Maternal B12 and folate concentrations were measured at 28 and 34 weeks of gestation. At 2 y, the Developmental Assessment Scale for Indian Infants was used to determine motor and mental developmental quotients and the Vineland Social Maturity Scale for the social developmental quotient. Overall, 62% of the mothers had low B12 levels (development was associated with maternal folate at 28 and 34 weeks of gestation. Mental and social development quotients were associated positively with head circumference and negatively with birth weight. In addition, pregnancy B12 and folate were positively associated with mental and social development quotients. Maternal B12 and folate during intrauterine life may favorably influence brain development and function. Pregnancy provides a window of opportunity to enhance fetal psychomotor (motor and mental) development.

  16. Efficacy of vitamin B12 combined with metformin in treating type 2 diabetes and its effect on homocysteine

    Directory of Open Access Journals (Sweden)

    Na Geng

    2016-03-01

    Full Text Available Objective: To observe and analyze Vitamin B12 combined with metformin treat for the type 2 diabetes, which affect the homocysteine. Methods: 92 cases of type 2 diabetes were selected in our hospital for treatment and study from October 2014 to April 2014. All patients were randomly divided into control group (46 cases and observation group (46 cases. Treatment of patients in the control group: patients were treated by metformin; observation group patients: Take vitamin B12 to patients treated with metformin. Finally, patient outcomes, as well as vitamin B12 and homocysteine in patients before and after treatment were analyzed. Results: Before treatment, all patients vitamin B12 content difference comparisons were no significant differences (P>0.05. Patients were treated in January, June and 1 year after the vitamin B12 content of the observation group were significantly higher in patients with vitamin B12 levels of data compared to each other there was a significant difference (P0.05. Patients were treated in January, June and 1 year after the homocysteine content of the observation group were not significantly reduced, the control group of patients with homocysteine increased significantly (P<0.000 1. Conclusions: Vitamin B12 combined with metformin in type 2 diabetes treatment, can significantly increase a patient's body to control homocysteine, while the treatment effect is obvious, clinical recommendations widely implemented.

  17. Vitamin B12 deficiency results in severe oxidative stress, leading to memory retention impairment in Caenorhabditis elegans.

    Science.gov (United States)

    Bito, Tomohiro; Misaki, Taihei; Yabuta, Yukinori; Ishikawa, Takahiro; Kawano, Tsuyoshi; Watanabe, Fumio

    2017-04-01

    Oxidative stress is implicated in various human diseases and conditions, such as a neurodegeneration, which is the major symptom of vitamin B 12 deficiency, although the underlying disease mechanisms associated with vitamin B 12 deficiency are poorly understood. Vitamin B 12 deficiency was found to significantly increase cellular H 2 O 2 and NO content in Caenorhabditis elegans and significantly decrease low molecular antioxidant [reduced glutathione (GSH) and L-ascorbic acid] levels and antioxidant enzyme (superoxide dismutase and catalase) activities, indicating that vitamin B 12 deficiency induces severe oxidative stress leading to oxidative damage of various cellular components in worms. An NaCl chemotaxis associative learning assay indicated that vitamin B 12 deficiency did not affect learning ability but impaired memory retention ability, which decreased to approximately 58% of the control value. When worms were treated with 1mmol/L GSH, L-ascorbic acid, or vitamin E for three generations during vitamin B 12 deficiency, cellular malondialdehyde content as an index of oxidative stress decreased to the control level, but the impairment of memory retention ability was not completely reversed (up to approximately 50%). These results suggest that memory retention impairment formed during vitamin B 12 deficiency is partially attributable to oxidative stress. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Non-Darcy flow of water-based carbon nanotubes with nonlinear radiation and heat generation/absorption

    Directory of Open Access Journals (Sweden)

    T. Hayat

    2018-03-01

    Full Text Available Here modeling and computations are presented to introduce the novel concept of Darcy-Forchheimer three-dimensional flow of water-based carbon nanotubes with nonlinear thermal radiation and heat generation/absorption. Bidirectional stretching surface induces the flow. Darcy’s law is commonly replace by Forchheimer relation. Xue model is implemented for nonliquid transport mechanism. Nonlinear formulation based upon conservation laws of mass, momentum and energy is first modeled and then solved by optimal homotopy analysis technique. Optimal estimations of auxiliary variables are obtained. Importance of influential variables on the velocity and thermal fields is interpreted graphically. Moreover velocity and temperature gradients are discussed and analyzed. Physical interpretation of influential variables is examined. Keywords: Porous medium, Heat generation/absorption, SWCNTs and MWCNTs, Nonlinear radiation

  19. Nitrous Oxide Abuse and Vitamin B12 Action in a 20-Year-Old Woman: A Case Report.

    Science.gov (United States)

    Duque, Miriam Andrea; Kresak, Jesse L; Falchook, Adam; Harris, Neil S

    2015-01-01

    Herein, we report a case of a 20-year-old (ethnicity not reported) woman with a history of nitrous oxide abuse and clinical symptoms consistent with spinal cord subacute combined degeneration with associated low serum concentrations of vitamin B12, elevated methylmalonic acid levels, and radiologic evidence of demyelination of the dorsal region of the spinal column. The health of the patient improved dramatically with B12 supplementation. In this case, we discuss the interaction of nitrous oxide with the enzymatic pathways involved in the biochemistry of vitamin B12. Copyright© by the American Society for Clinical Pathology (ASCP).

  20. The need for a sufficient number of low level sera in comparisons of different serum vitamin B12 assays

    International Nuclear Information System (INIS)

    Gijzen, A.H.J.; Kock, H.W. de; Meulendijk, P.N.; Schmidt, N.A.; Schopman, W.; Tertoolen, J.F.W.; Voogd, C.E.

    1983-01-01

    Eight radiochemical methods for the assay of vitamin B 12 in serum were compared with the microbiological assay with Lactobacillus leichmannii ATCC 7830 using 198 individual sera of patients. There was a good agreement between the results of most samples with some kits and the microbiological assay. However, especially in the sera of vitamin B 12 -deficient patients large discrepancies between the results could occur. These variations were due to both the kits used and the performance of the assays in different laboratories. A sufficient number of non-pooled sera of vitamin B 12 -deficient patients should be included in investigations to validate radiochemical methods. (Auth.)

  1. TOTAL PARENTERAL NUTRITION (TPN: ROLE OF RIBOFLAVIN (VITAMIN B2 AND CYANOCOBALAMIN (VITAMIN B12

    Directory of Open Access Journals (Sweden)

    Samina Shiekh

    2015-06-01

    Full Text Available Total parenteral nutrition (TPN replaces and maintains essential nutrients in patients in whom oral or tube feedings are contraindicated or inadequate. A nutritional assessment must be carried out before initiating TPN in order to determine nutritional needs and any metabolic changes due to the patient’s underlying condition, medications or concurrent therapies. In addition to carbohydrates, proteins and fats, certain amounts of micronutirents are also added to TPN solutions. These micronutrients include electrolytes, vitamins, and trace minerals. This review highlights some basic concepts regarding the use and formulation of TPNs along with their advantages and disadvantages and the importance of water soluble vitamins B2 and B12 in human nutrition.

  2. Structural basis for receptor recognition of vitamin-B(12)-intrinsic factor complexes

    DEFF Research Database (Denmark)

    Andersen, Christian Brix Folsted; Madsen, Mette; Storm, Tina

    2010-01-01

    Cobalamin (Cbl, vitamin B(12)) is a bacterial organic compound and an essential coenzyme in mammals, which take it up from the diet. This occurs by the combined action of the gastric intrinsic factor (IF) and the ileal endocytic cubam receptor formed by the 460-kilodalton (kDa) protein cubilin...... and the 45-kDa transmembrane protein amnionless. Loss of function of any of these proteins ultimately leads to Cbl deficiency in man. Here we present the crystal structure of the complex between IF-Cbl and the cubilin IF-Cbl-binding-region (CUB(5-8)) determined at 3.3 A resolution. The structure provides...... of how Cbl indirectly induces ligand-receptor coupling. Finally, the comparison of Ca(2+)-binding CUB domains and the low-density lipoprotein (LDL) receptor-type A modules suggests that the electrostatic pairing of a basic ligand arginine/lysine residue with Ca(2+)-coordinating acidic aspartates...

  3. Vitamin B12 Metabolism during Pregnancy and in Embryonic Mouse Models

    Directory of Open Access Journals (Sweden)

    Maira A. Moreno-Garcia

    2013-09-01

    Full Text Available Vitamin B12 (cobalamin, Cbl is required for cellular metabolism. It is an essential coenzyme in mammals for two reactions: the conversion of homocysteine to methionine by the enzyme methionine synthase and the conversion of methylmalonyl-CoA to succinyl-CoA by the enzyme methylmalonyl-CoA mutase. Symptoms of Cbl deficiency are hematological, neurological and cognitive, including megaloblastic anaemia, tingling and numbness of the extremities, gait abnormalities, visual disturbances, memory loss and dementia. During pregnancy Cbl is essential, presumably because of its role in DNA synthesis and methionine synthesis; however, there are conflicting studies regarding an association between early pregnancy loss and Cbl deficiency. We here review the literature about the requirement for Cbl during pregnancy, and summarized what is known of the expression pattern and function of genes required for Cbl metabolism in embryonic mouse models.

  4. Designing learning curves for carbon capture based on chemical absorption according to the minimum work of separation

    International Nuclear Information System (INIS)

    Rochedo, Pedro R.R.; Szklo, Alexandre

    2013-01-01

    Highlights: • This work defines the minimum work of separation (MWS) for a capture process. • Findings of the analysis indicated a MWS of 0.158 GJ/t for post-combustion. • A review of commercially available processes based on chemical absorption was made. • A review of learning models was conducted, with the addition on a novel model. • A learning curve for post-combustion carbon capture was successfully designed. - Abstract: Carbon capture is one of the most important alternatives for mitigating greenhouse gas emissions in energy facilities. The post-combustion route based on chemical absorption with amine solvents is the most feasible alternative for the short term. However, this route implies in huge energy penalties, mainly related to the solvent regeneration. By defining the minimum work of separation (MWS), this study estimated the minimum energy required to capture the CO 2 emitted by coal-fired thermal power plants. Then, by evaluating solvents and processes and comparing it to the MWS, it proposes the learning model with the best fit for the post-combustion chemical absorption of CO 2 . Learning models are based on earnings from experience, which can include the intensity of research and development. In this study, three models are tested: Wright, DeJong and D and L. Findings of the thermochemical analysis indicated a MWS of 0.158 GJ/t for post-combustion. Conventional solvents currently present an energy penalty eight times the MWS. By using the MWS as a constraint, this study found that the D and L provided the best fit to the available data of chemical solvents and absorption plants. The learning rate determined through this model is very similar to the ones found in the literature

  5. Determination of absorption coefficient based on laser beam thermal blooming in gas-filled tube.

    Science.gov (United States)

    Hafizi, B; Peñano, J; Fischer, R; DiComo, G; Ting, A

    2014-08-01

    Thermal blooming of a laser beam propagating in a gas-filled tube is investigated both analytically and experimentally. A self-consistent formulation taking into account heating of the gas and the resultant laser beam spreading (including diffraction) is presented. The heat equation is used to determine the temperature variation while the paraxial wave equation is solved in the eikonal approximation to determine the temporal and spatial variation of the Gaussian laser spot radius, Gouy phase (longitudinal phase delay), and wavefront curvature. The analysis is benchmarked against a thermal blooming experiment in the literature using a CO₂ laser beam propagating in a tube filled with air and propane. New experimental results are presented in which a CW fiber laser (1 μm) propagates in a tube filled with nitrogen and water vapor. By matching laboratory and theoretical results, the absorption coefficient of water vapor is found to agree with calculations using MODTRAN (the MODerate-resolution atmospheric TRANsmission molecular absorption database) and HITRAN (the HIgh-resolution atmospheric TRANsmission molecular absorption database).

  6. Energy and exergy analysis of a double effect absorption refrigeration system based on different heat sources

    International Nuclear Information System (INIS)

    Kaynakli, Omer; Saka, Kenan; Kaynakli, Faruk

    2015-01-01

    Highlights: • Energy and exergy analysis was performed on double effect series flow absorption refrigeration system. • The refrigeration system runs on various heat sources such as hot water, hot air and steam. • A comparative analysis was carried out on these heat sources in terms of exergy destruction and mass flow rate of heat source. • The effect of heat sources on the exergy destruction of high pressure generator was investigated. - Abstract: Absorption refrigeration systems are environmental friendly since they can utilize industrial waste heat and/or solar energy. In terms of heat source of the systems, researchers prefer one type heat source usually such as hot water or steam. Some studies can be free from environment. In this study, energy and exergy analysis is performed on a double effect series flow absorption refrigeration system with water/lithium bromide as working fluid pair. The refrigeration system runs on various heat sources such as hot water, hot air and steam via High Pressure Generator (HPG) because of hot water/steam and hot air are the most common available heat source for absorption applications but the first law of thermodynamics may not be sufficient analyze the absorption refrigeration system and to show the difference of utilize for different type heat source. On the other hand operation temperatures of the overall system and its components have a major effect on their performance and functionality. In this regard, a parametric study conducted here to investigate this effect on heat capacity and exergy destruction of the HPG, coefficient of performance (COP) of the system, and mass flow rate of heat sources. Also, a comparative analysis is carried out on several heat sources (e.g. hot water, hot air and steam) in terms of exergy destruction and mass flow rate of heat source. From the analyses it is observed that exergy destruction of the HPG increases at higher temperature of the heat sources, condenser and absorber, and lower

  7. The clinical observation on the treatment of irradiated injuries of the skin and mucosa by using vitamin B12

    International Nuclear Information System (INIS)

    Ji, Hui; Li, Jianchao; Xie, Xiuzhen; Chen, Quiang; Yang, Yongguang

    1987-01-01

    A clinical study of the treatment of irradiated skin and mucosa injuries (40 cases). This paper introduces two methods of treating irradiated injuries of the skin and mucosa. By using Vitamin B 12 both externaly and applying in the mouth, we can stop the pain promptly, reduce the exudation, improve the growth of granulation and the healing of the ulcer especialy in the early acute stage. In addition Vitamin B 12 produces good effects on other kinds of skin injuries. Shu BaiKe considered that the skin had the same function as the liver, which includes various kinds of enzymes. We thought that using Vitamin B 12 externaly on skin injuries, it would be absorbed and join the RNA synthesizing process in the liver and skin. After applying Vitamin B 12 , the RNA content rose. The results of animal experiments coincided with clinial treatment. It clarified the mechanisms needed to treat the third degree acute irradiated skin injuries. (author)

  8. Cobalamin (Vitamin B12) Role on the Biochemical, Histological and Teratological Changes Induced in Diabetic Irradiated Pregnant Rats

    International Nuclear Information System (INIS)

    Ramadan, F.L.

    2013-01-01

    Vitamin B 12 called Cobalamin, is a water soluble vitamin with a key role in the normal function of the brain, nervous system, cell division and for the formation of blood. It is normally involved in the metabolism of every cell of the human body especially affecting DNA synthesis and regulation, fatty acid synthesis and energy production.The aim of the present study was to evaluate the role of vitamin B 12 intake on radiation induced damage in diabetic mothers.Diabetes was induced in female rats by intra-peritoneal injection of alloxan 150 mg/kg b.wt. dissolved in saline. Pregnant diabetic mothers were received vitamin B 12 0.1 mg/100 g b.wt. from the 1st up to 19th day of gestation. Meanwhile, pregnant diabetic rats were exposed to 0.6 Gy on the 7th and the 14th days of gestation. The increased incidence of malformations in diabetic pregnancy with an excess of free oxygen radicals in the embryos was recorded .Vitamin B12 supplementation to diabetic mother ameliorated radiation-induced damage which was obvious by diminishing the increase in glucose level, improving serum insulin level, glycogen content in the liver and ameliorating the decrease in glutathione (GSH) content in the liver of pregnant rats and their fetuses.In addition, vitamin B 12 treatment improved the decrease in red blood cells (RBCs), white blood cells (WBCs) and hemoglobin (Hb) of fetuses and DNA content in the liver tissues. Moreover, vitamin B 12 treatment lead to the regeneration of normal architecture of maternal and fetuses hepatic cells and blood vessels. It could be concluded that vitamin B 12 supplementation to diabetic mothers ameliorated the radiation effect which induced biochemical, histochemical, histological and teratological disorders.Furthermore, the results obtained showed that vitamin B 12 administration caused a protection to diabetic pregnant rats against embryo malformations induced by gamma rays

  9. Effects of γ-irradiation and cooking on vitamins B6 and B12 in grass prawns (Penaeus monodon)

    International Nuclear Information System (INIS)

    Hau, L.-B.; Liew, M.-S.

    1993-01-01

    The effects of radiation doses, irradiation temperature and a combined treatment of irradiation and cooking on the vitamin B 6 and B 12 contents of grass prawns have been studied. Grass prawns were irradiated at refrigerated (4 o C) or frozen (-20 o C) temperatures with different doses. A domestic cooling procedure was followed after irradiation. The changes in vitamins B 6 and B 12 of both raw and cooked grass prawns were evaluated. Results showed no significant changes of vitamin B 6 and B 12 in grass prawns with a radiation dose up to 7 kGy at either 4 o C or -20 o C. Irradiation at 4 o C caused more destruction of vitamin B 12 but not vitamin B 6 than did irradiation at -20 o C in grass prawns. There was significant destruction of both vitamins B 6 and B 12 in unirradiated samples during cooking. The introduction of the irradiation process before cooking had no effect on either vitamin. These results indicate that the loss of vitamins B 6 and B 12 in the combined treatments was caused mainly by thermal destruction. (author)

  10. Determination of water pH using absorption-based optical sensors: evaluation of different calculation methods

    Science.gov (United States)

    Wang, Hongliang; Liu, Baohua; Ding, Zhongjun; Wang, Xiangxin

    2017-02-01

    Absorption-based optical sensors have been developed for the determination of water pH. In this paper, based on the preparation of a transparent sol-gel thin film with a phenol red (PR) indicator, several calculation methods, including simple linear regression analysis, quadratic regression analysis and dual-wavelength absorbance ratio analysis, were used to calculate water pH. Results of MSSRR show that dual-wavelength absorbance ratio analysis can improve the calculation accuracy of water pH in long-term measurement.

  11. Exceptional Structural Compliance of the B12F122- Superweak Anion.

    Science.gov (United States)

    Peryshkov, Dmitry V; Strauss, Steven H

    2017-04-03

    The single-crystal X-ray structures, thermogravimetric analyses, and/or FTIR spectra of a series of salts of the B 12 F 12 2- anion and homoleptic Ag(L) n + cations are reported (L = CH 2 Cl 2 , n = 2; L = PhCH 3 , n = 3; L = CH 3 CN; n = 2-4; L = CO, n = 1, 2). The superweak-anion nature of B 12 F 12 2- (Y 2- ) was demonstrated by the rapid reaction of microcrystalline Ag 2 (Y) with 1 atm of CO to form a nonclassical silver(I) carbonyl compound with an FTIR ν(CO) band at 2198 cm -1 (and with the proposed formula [Ag(CO) n ] 2 [Y]). In contrast, microcrystalline Ag 2 (B 12 Cl 12 ) did not exhibit ν(CO) bands and therefore did not form Ag(CO) + species, even after 32 h under 24 atm of CO. When Ag 2 (Y) was treated with carbon monoxide pressures higher than 1 atm, a new ν(CO) band at 2190 cm -1 appeared, which is characteristic of a Ag(CO) 2 + dicarbonyl cation. Both Ag 2 (CH 3 CN) 8 (Y) and Ag 2 (CH 3 CN) 5 (Y) rapidly lost coordinated CH 3 CN at 25 °C to form Ag 2 (CH 3 CN) 4 (Y), which formed solvent-free Ag 2 (Y) only after heating above 100 °C. Similarly, Ag 2 (PhCH 3 ) 6 (Y) rapidly lost coordinated PhCH 3 at 25 °C to form Ag 2 (PhCH 3 ) 2 (Y), which formed Ag 2 (Y) after heating above 150 °C, and Ag 2 (CH 2 Cl 2 ) 4 (Y) rapidly lost three of the four coordinated CH 2 Cl 2 ligands between 25 and 100 °C and formed Ag 2 (Y) when it was heated above 200 °C. Solvent-free Ag 2 (Y) was stable until it was heated above 380 °C. The rapid evaporative loss of coordinated ligands at 25 °C from nonporous crystalline solids requires equally rapid structural reorganization of the lattice and is one of three manifestations of the structural compliance of the Y 2- anion reported in this work. The second, more quantitative, manifestation is that Ag + bond-valence sums for Ag 2 (CH 3 CN) n (Y) are virtually constant, 1.20 ± 0.03, for n = 8, 5, 4, because the Y 2- anion precisely compensated for the lost CH 3 CN ligands by readily forming the necessary number of weak

  12. Efficient, Absorption-Powered Artificial Muscles Based on Carbon Nanotube Hybrid Yarns.

    Science.gov (United States)

    Lima, Márcio Dias; Hussain, Mohammad W; Spinks, Geoffrey M; Naficy, Sina; Hagenasr, Daniela; Bykova, Julia S; Tolly, Derrick; Baughman, Ray H

    2015-07-01

    A new type of absorption-powered artificial muscle provides high performance without needing a temperature change. These muscles, comprising coiled carbon nanotube fibers infiltrated with silicone rubber, can contract up to 50% to generate up to 1.2 kJ kg(-1) . The drive mechanism for actuation is the rubber swelling during exposure to a nonpolar solvent. Theoretical energy efficiency conversion can be as high as 16%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Magnetic dependence of cyclotron transition absorption in piezoelectric materials based on the quantum transport theory

    International Nuclear Information System (INIS)

    Lee, S.H.; Lee, J.T.; Sug, J.Y.; Lee, J.H.; Sa-Gong, G.

    2011-01-01

    We investigated theoretically the magnetic field dependence of the quantum optical transition of quasi 2-Dimensional Landau splitting system, in CdS and ZnO. Through the analysis of the current work, we found the increasing properties of the optical Quantum Transition Line Shapes (QTLSs) which show the absorption power and the Quantum Transition Line Widths(QTLWs) with the magnetic-field in CdS and ZnO. We also found that QTLW, γ(B) total of CdS total of ZnO in the magnetic field region B < 25 Tesla.

  14. A neural network based approach for determination of optical scattering and absorption coefficients of biological tissue

    International Nuclear Information System (INIS)

    Warncke, D; Lewis, E; Leahy, M; Lochmann, S

    2009-01-01

    The propagation of light in biological tissue depends on the absorption and reduced scattering coefficient. The aim of this project is the determination of these two optical properties using spatially resolved reflectance measurements. The sensor system consists of five laser sources at different wavelengths, an optical fibre probe and five photodiodes. For these kinds of measurements it has been shown that an often used solution of the diffusion equation can not be applied. Therefore a neural network is being developed to extract the needed optical properties out of the reflectance data. Data sets for the training, validation and testing process are provided by Monte Carlo Simulations.

  15. Absolute frequency atlas from 915 nm to 985 nm based on laser absorption spectroscopy of iodine

    Science.gov (United States)

    Nölleke, Christian; Raab, Christoph; Neuhaus, Rudolf; Falke, Stephan

    2018-04-01

    This article reports on laser absorption spectroscopy of iodine gas between 915 nm and 985 nm. This wavelength range is scanned utilizing a narrow linewidth and mode-hop-free tunable diode-laser whose frequency is actively controlled using a calibrated wavelength meter. This allows us to provide an iodine atlas that contains almost 10,000 experimentally observed reference lines with an uncertainty of 50 MHz. For common lines, good agreement is found with a publication by Gerstenkorn and Luc (1978). The new rich dataset allows existing models of the iodine molecule to be refined and can serve as a reference for laser frequency calibration and stabilization.

  16. [Gas pipeline leak detection based on tunable diode laser absorption spectroscopy].

    Science.gov (United States)

    Zhang, Qi-Xing; Wang, Jin-Jun; Liu, Bing-Hai; Cai, Ting-Li; Qiao, Li-Feng; Zhang, Yong-Ming

    2009-08-01

    The principle of tunable diode laser absorption spectroscopy and harmonic detection technique was introduced. An experimental device was developed by point sampling through small multi-reflection gas cell. A specific line near 1 653. 7 nm was targeted for methane measurement using a distributed feedback diode laser as tunable light source. The linearity between the intensity of second harmonic signal and the concentration of methane was determined. The background content of methane in air was measured. The results show that gas sensors using tunable diode lasers provide a high sensitivity and high selectivity method for city gas pipeline leak detection.

  17. Wavelength modulation spectroscopy--digital detection of gas absorption harmonics based on Fourier analysis.

    Science.gov (United States)

    Mei, Liang; Svanberg, Sune

    2015-03-20

    This work presents a detailed study of the theoretical aspects of the Fourier analysis method, which has been utilized for gas absorption harmonic detection in wavelength modulation spectroscopy (WMS). The lock-in detection of the harmonic signal is accomplished by studying the phase term of the inverse Fourier transform of the Fourier spectrum that corresponds to the harmonic signal. The mathematics and the corresponding simulation results are given for each procedure when applying the Fourier analysis method. The present work provides a detailed view of the WMS technique when applying the Fourier analysis method.

  18. Functional identification in Lactobacillus reuteri of a PocR-like transcription factor regulating glycerol utilization and vitamin B12 synthesis

    Directory of Open Access Journals (Sweden)

    Saulnier Delphine MA

    2011-07-01

    Full Text Available Abstract Background Lactobacillus reuteri harbors the genes responsible for glycerol utilization and vitamin B12 synthesis within a genetic island phylogenetically related to gamma-Proteobacteria. Within this island, resides a gene (lreu_1750 that based on its genomic context has been suggested to encode the regulatory protein PocR and presumably control the expression of the neighboring loci. However, this functional assignment is not fully supported by sequence homology, and hitherto, completely lacks experimental confirmation. Results In this contribution, we have overexpressed and inactivated the gene encoding the putative PocR in L. reuteri. The comparison of these strains provided metabolic and transcriptional evidence that this regulatory protein controls the expression of the operons encoding glycerol utilization and vitamin B12 synthesis. Conclusions We provide clear experimental evidence for assigning Lreu_1750 as PocR in Lactobacillus reuteri. Our genome-wide transcriptional analysis further identifies the loci contained in the PocR regulon. The findings reported here could be used to improve the production-yield of vitamin B12, 1,3-propanediol and reuterin, all industrially relevant compounds.

  19. Unified picture of the photoexcitations in phenylene-based conjugated polymers: Universal spectral and dynamical features in subpicosecond transient absorption

    International Nuclear Information System (INIS)

    Kraabel, B.; Klimov, V. I.; Kohlman, R.; Xu, S.; Wang, H-L.; McBranch, D. W.

    2000-01-01

    Using subpicosecond transient absorption spectroscopy, we investigate the primary photoexcitations in thin films and solutions of several phenylene-based conjugated polymers and an oligomer. We identify several features in the transient absorption spectra and dynamics that are common to all of the materials which we studied from this family. The first spectral feature is a photoinduced absorption (PA) band peaking near 1 eV that has intensity-dependent dynamics that match the stimulated emission dynamics exactly over two orders of magnitude in excitation density. This band is associated with singlet intrachain excitons. The second spectral feature (observed only in thin films and aggregated solutions) is a PA band peaking near 1.8 eV, that is longer lived than the 1 eV exciton PA band, and that has dynamics that are independent (or weakly dependent) on excitation density. This feature is attributed to polarons, generated through a mechanism that is sample dependent. In pristine samples, polarons are generated via a mechanism that is quadratic in exciton density, whereas in photodegraded samples or samples doped with electron acceptors, the generation mechanism becomes linear in exciton density. (c) 2000 The American Physical Society

  20. Screening of the vitamin B12 status in an urban population sample from Romania: a pilot study

    Directory of Open Access Journals (Sweden)

    Crăciun Elena C.

    2014-06-01

    Full Text Available Scopul acestui studiu a fost evaluarea statusului vitaminei B12 într-un eşantion al populaţiei urbane adulte din România. În studiu au fost incluşi 80 de subiecţi non-vegetarieni, cu vârste cuprinse între 19 şi 74,6 ani, care nu au utilizat suplimente de vitamina B12 sau alimente fortificate cu vitamina B12. Dozarea vitaminei B12 serice s-a realizat prin metoda imunochimică cu detecţie prin chemiluminiscenţă pe analizor Elecsys 2010 (Roche. Concentraţia serică a vitaminei B12 s-a încadrat în intervalul de referinţă (191-663 pg/ml la 93,75% (95% CI 86,2-97,3% din subiecţi. La aceşti subiecţi nu s-au evidenţiat corelaţii seminificative statistic între concentraţia serică a vitaminei B12 şi vârsta subiecţilor sau concentraţia hemoglobinei. Nu s-au găsit nici diferenţe semnificative (p>0.05 ale statusului vitaminic la femei faţă de bărbaţi. Concentraţia serică a vitaminei B12 s-a situat sub limita inferioară a intervalului de referinţă la 5% (95%CI 1,96-12,16% din subiecţii investigaţi, fiind asociată tratamentului cu contraceptive orale, inhibitori ai pompei de protoni (IPP respectiv sindromului de colon iritabil. La un număr mare de subiecţi cu vârsta sub 50 de ani, concentraţia serică a vitaminei B12 s-a încadrat în limitele corespunzătoare statusului marginal. Rezultatele studiului sugerează necesitatea efectuării screeningului statusului vitaminei B12 la întreaga populaţie, importanţa identificării factorilor responsabili de prevalenţa crescută a statusului marginal şi importanţa monitorizării statusului vitaminei B12 la subiecţii care fac tratament îndelungat cu unele medicamente.

  1. Nutrition and magnesium absorption

    NARCIS (Netherlands)

    Brink, E.J.

    1992-01-01

    The influence of various nutrients present in dairy products and soybean-based products on absorption of magnesium has been investigated. The studies demonstrate that soybean protein versus casein lowers apparent magnesium absorption in rats through its phytate component. However, true

  2. Zeeman atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Loos-Vollebregt, M.T.C. de.

    1980-01-01

    A new method of background correction in atomic absorption spectroscopy has recently been introduced, based on the Zeeman splitting of spectral lines in a magnetic field. A theoretical analysis of the background correction capability observed in such instruments is presented. A Zeeman atomic absorption spectrometer utilizing a 50 Hz sine wave modulated magnetic field is described. (Auth.)

  3. The effect of a nanofilled resin-based coating on water absorption by teeth restored with glass ionomer.

    Science.gov (United States)

    Hankins, Amanda D; Hatch, Robert H; Benson, Jarred H; Blen, Bernard J; Tantbirojn, Daranee; Versluis, Antheunis

    2014-04-01

    A nanofilled, resin-based light-cured coating (G-Coat Plus, GC America, Alsip, Ill.) may reduce water absorption by glass ionomers. The authors investigated this possibility by measuring cuspal flexure caused by swelling of glass ionomer-restored teeth. The authors cut large mesio-occlusodistal slots (4-millimeter wide, 4-mm deep) in 12 extracted premolars and restored them with a glass ionomer cement (Fuji IX GP Extra, GC America). Six teeth were coated, and the other six were uncoated controls. The authors digitized the teeth in three dimensions by using an optical scanner after preparation and restoration and during an eight-week storage in water. They calculated cuspal flexure and analyzed the results by using an analysis of variance and Student-Newman-Keuls post hoc tests (significance level .05). They used dye penetration along the interface to verify bonding. Inward cuspal flexure indicated restoration shrinkage. Coated restorations had significantly higher flexure (mean [standard deviation], -11.9 [3.5] micrometers) than did restorations without coating (-7.3 [1.5] μm). Flexure in both groups decreased significantly (P < .05) during water storage and, after eight weeks, it changed to expansion for uncoated control restorations. Dye penetration along the interfaces was not significant, which ruled out debonding as the cause of cuspal relaxation. Teeth restored with glass ionomer cement exhibited shrinkage, as seen by inward cuspal flexure. The effect of the protective coating on water absorption was evident in the slower shrinkage compensation. The study results show that teeth restored with glass ionomers exhibited setting shrinkage that deformed tooth cusps. Water absorption compensated for the shrinkage. Although the coating may be beneficial for reducing water absorption, it also slows the shrinkage compensation rate (that is, the rate that hygroscopic expansion compensates for cuspal flexure from shrinkage).

  4. Design and implementation of a laser-based absorption spectroscopy sensor for in situ monitoring of biomass gasification

    Science.gov (United States)

    Viveros Salazar, David; Goldenstein, Christopher S.; Jeffries, Jay B.; Seiser, Reinhard; Cattolica, Robert J.; Hanson, Ronald K.

    2017-12-01

    Research to demonstrate in situ laser-absorption-based sensing of H2O, CH4, CO2, and CO mole fraction is reported for the product gas line of a biomass gasifier. Spectral simulations were used to select candidate sensor wavelengths that optimize sensitive monitoring of the target species while minimizing interference from other species in the gas stream. A prototype sensor was constructed and measurements performed in the laboratory at Stanford to validate performance. Field measurements then were demonstrated in a pilot scale biomass gasifier at West Biofuels in Woodland, CA. The performance of a prototype sensor was compared for two sensor strategies: wavelength-scanned direct absorption (DA) and wavelength-scanned wavelength modulation spectroscopy (WMS). The lasers used had markedly different wavelength tuning response to injection current, and modern distributed feedback lasers (DFB) with nearly linear tuning response to injection current were shown to be superior, leading to guidelines for laser selection for sensor fabrication. Non-absorption loss in the transmitted laser intensity from particulate scattering and window fouling encouraged the use of normalized WMS measurement schemes. The complications of using normalized WMS for relatively large values of absorbance and its mitigation are discussed. A method for reducing adverse sensor performance effects of a time-varying WMS background signal is also presented. The laser absorption sensor provided measurements with the sub-second time resolution needed for gasifier control and more importantly provided precise measurements of H2O in the gasification products, which can be problematic for the typical gas chromatography sensors used by industry.

  5. Improved hydrogen absorption and desorption kinetics of magnesium-based alloy via addition of yttrium

    Science.gov (United States)

    Yang, Tai; Li, Qiang; Liu, Ning; Liang, Chunyong; Yin, Fuxing; Zhang, Yanghuan

    2018-02-01

    Yttrium (Y) is selected to modify the microstructure of magnesium (Mg) to improve the hydrogen storage performance. Thereby, binary alloys with the nominal compositions of Mg24Yx (x = 1-5) are fabricated by inexpensive casting technique. Their microstructure and phase transformation during hydriding and dehydriding process are characterized by using X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy analysis. The isothermal hydrogen absorption and desorption kinetics are also measured by a Sievert's-type apparatus at various temperatures. Typical multiphase structures of binary alloy can be clearly observed. All of these alloys can reversibly absorb and desorb large amount of hydrogen at proper temperatures. The addition of Y markedly promotes the hydrogen absorption kinetics. However, it results in a reduction of reversible hydrogen storage capacity. A maximum value of dehydrogenation rate is observed with the increase of Y content. The Mg24Y3 alloy has the optimal desorption kinetic performance, and it can desorb about 5.4 wt% of hydrogen at 380 °C within 12 min. Combining Johnson-Mehl-Avrami kinetic model and Arrhenius equation, the dehydrogenation activation energy of the alloys are evaluated. The Mg24Y3 alloy also has the lowest dehydrogenation activation energy (119 kJ mol-1).

  6. In situ measurements of the optical absorption of dioxythiophene-based conjugated polymers

    Science.gov (United States)

    Hwang, J.; Schwendeman, I.; Ihas, B. C.; Clark, R. J.; Cornick, M.; Nikolou, M.; Argun, A.; Reynolds, J. R.; Tanner, D. B.

    2011-05-01

    Conjugated polymers can be reversibly doped by electrochemical means. This doping introduces new subband-gap optical absorption bands in the polymer while decreasing the band-gap absorption. To study this behavior, we have prepared an electrochemical cell allowing in situ measurements of the optical properties of the polymer. The cell consists of a thin polymer film deposited on gold-coated Mylar behind which is another polymer that serves as a counterelectrode. An infrared transparent window protects the upper polymer from ambient air. By adding a gel electrolyte and making electrical connections to the polymer-on-gold films, one may study electrochromism in a wide spectral range. As the cell voltage (the potential difference between the two electrodes) changes, the doping level of the conjugated polymer films is changed reversibly. Our experiments address electrochromism in poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-dimethylpropylenedioxythiophene) (PProDOT-Me2). This closed electrochemical cell allows the study of the doping induced subband-gap features (polaronic and bipolaronic modes) in these easily oxidized and highly redox switchable polymers. We also study the changes in cell spectra as a function of polymer thickness and investigate strategies to obtain cleaner spectra, minimizing the contributions of water and gel electrolyte features.

  7. Acquired thermotolerance and heat shock in the extremely thermophilic archaebacterium Sulfolobus sp. strain B12.

    Science.gov (United States)

    Trent, J D; Osipiuk, J; Pinkau, T

    1990-03-01

    The extreme thermophile Sulfolobus sp. strain B12 exhibits an acquired thermotolerance response. Thus, survival of cells from a 70 degrees C culture at the lethal temperature of 92 degrees C was enhanced by as much as 6 orders of magnitude over a 2-h period if the culture was preheated to 88 degrees C for 60 min or longer before being exposed to the lethal temperature. In eubacteria and eucaryotes, acquired thermotolerance correlates with the induced synthesis of a dozen or so proteins known as heat shock proteins. In this Sulfolobus species, it correlates with the preferential synthesis of primarily one major protein (55 kilodaltons) and, to a much lesser extent, two minor proteins (28 and 35 kilodaltons). Since the synthesis of all other proteins was radically reduced and these proteins were apparently not degraded or exported, their relative abundance within the cell increased during the time the cells were becoming thermotolerant. They could not yet be related to known heat shock proteins. In immunoassays, they were not cross-reactive with antibodies against heat shock proteins from Escherichia coli (DnaK and GroE), which are highly conserved between eubacteria and eucaryotes. However, it appears that if acquired thermotolerance depends on the synthesis of protective proteins, then in this extremely thermophilic archaebacterium it depends primarily on one protein.

  8. Reductive dehalogenase structure suggests a mechanism for B12-dependent dehalogenation.

    Science.gov (United States)

    Payne, Karl Ap; Quezada, Carolina P; Fisher, Karl; Dunstan, Mark S; Collins, Fraser A; Sjuts, Hanno; Levy, Colin; Hay, Sam; Rigby, Stephen Ej; Leys, David

    2015-01-22

    Organohalide chemistry underpins many industrial and agricultural processes, and a large proportion of environmental pollutants are organohalides. Nevertheless, organohalide chemistry is not exclusively of anthropogenic origin, with natural abiotic and biological processes contributing to the global halide cycle. Reductive dehalogenases are responsible for biological dehalogenation in organohalide respiring bacteria, with substrates including polychlorinated biphenyls or dioxins. Reductive dehalogenases form a distinct subfamily of cobalamin (B12)-dependent enzymes that are usually membrane associated and oxygen sensitive, hindering detailed studies. Here we report the characterization of a soluble, oxygen-tolerant reductive dehalogenase and, by combining structure determination with EPR (electron paramagnetic resonance) spectroscopy and simulation, show that a direct interaction between the cobalamin cobalt and the substrate halogen underpins catalysis. In contrast to the carbon-cobalt bond chemistry catalysed by the other cobalamin-dependent subfamilies, we propose that reductive dehalogenases achieve reduction of the organohalide substrate via halogen-cobalt bond formation. This presents a new model in both organohalide and cobalamin (bio)chemistry that will guide future exploitation of these enzymes in bioremediation or biocatalysis.

  9. Development of an electrochemical biosensor for vitamin B12 using D-phenylalanine nanotubes

    Science.gov (United States)

    Moazeni, Maryam; Karimzadeh, Fathallah; Kermanpur, Ahmad; Allafchian, Alireza

    2018-01-01

    In the past decades, biosensors are one of the most interesting topics among researchers and scientist. The biosensors are used in several applications such as determining food quality, control and diagnose clinical problems and metabolic control. Therefore, many efforts have been carried out to design and develop a new generation of these systems. On the other hand nanotechnology by improving the performance of sensors has created an excellent outlook. Using nanomaterials such as nanoparticles, nanotubes, nanowires, and nanorods in diagnostic tools has been significantly increased accuracy, sensitivity and improved detection limits in sensors. In this study, the one-dimensional morphology of the D-phenylalanine was assembled on the surface of the gold electrode. In the next step electrochemical performance of the modified electrode was investigated by Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and Differential Pals Voltammograms (DPV). Finally, by measuring the different concentrations of vitamin B12, the detection limit of the biosensor was obtained 1.6 µM.

  10. Synthesis, solution and crystal structure of the coenzyme B(12) analogue Co(β)-2'-fluoro-2',5'-dideoxyadenosylcobalamin.

    Science.gov (United States)

    Hunger, Miriam; Wurst, Klaus; Kräutler, Bernhard

    2015-07-01

    Crystal structure analyses have helped to decipher the mode of binding of coenzyme B12 (AdoCbl) in the active site of AdoCbl-dependent enzymes. However, the question of how such enzymes perform their radical reactions is still incompletely answered. A pioneering study by Gruber and Kratky of AdoCbl-dependent glutamate mutase (GLM) laid out a path for the movement of the catalytically active 5'-deoxyadenosyl radical, in which H-bonds between the protein and the 2'- and 3'-OH groups of the protein bound AdoCbl would play a decisive role. Studies with correspondingly modified coenzyme B12-analogues are of interest to gain insights into cofactor binding and enzyme mechanism. Here we report the preparation of Coβ-2'-fluoro-2',5'-dideoxyadenosylcobalamin (2'FAdoCbl), which lacks the 2'-OH group critical for the interaction in enzymes. 2'FAdoCbl was prepared by alkylation of cob(I)alamin, obtained from the electrochemical reduction of aquocobalamin. Spectroscopic data and a single crystal X-ray analysis of 2'FAdoCbl established its structure, which was very similar to that one of coenzyme B12. 2'FAdoCbl is a (19)F NMR active mimic of coenzyme B12 that may help to gain insights into binding interactions of coenzyme B12 with AdoCbl-dependent enzymes, proteins of B12 transport and of AdoCbl-biosynthesis, as well as with B12-riboswitches. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Chronic transgenerational vitamin B12 deficiency of severe and moderate magnitudes modulates adiposity-probable underlying mechanisms.

    Science.gov (United States)

    Ghosh, Shampa; Sinha, Jitendra Kumar; Muralikrishna, Bojanapalli; Putcha, Uday Kumar; Raghunath, Manchala

    2017-05-06

    We have demonstrated previously that severe but not moderate vitamin B12 deficiency altered body composition and induced adiposity in female C57BL/6 mice. This study aims to elucidate the effects of chronic transgenerational dietary vitamin B12 restriction on body composition and various biochemical parameters in the F1 generation offspring of our mouse models of severe and moderate vitamin B12 deficiency established earlier. Female weanling C57BL/6 mice received, ad libitum, for 4 weeks a (i) control diet, (ii) vitamin B12-restricted diet with pectin as dietary fiber (severely deficient diet), or (iii) vitamin B12-restricted diet with cellulose as dietary fiber (moderately deficient diet) and then mated with control males. The offspring of control and severely deficient dams continued on the respective diets of their mothers. Few moderately deficient dams were rehabilitated to control diet from parturition and their pups were weaned to control diet. Also, some offspring born to moderately B12 deficient dams were weaned to control diet, while others continued on the same diet as their mothers. Various parameters were determined in the F1 offspring after 12 and 36 weeks of feeding. The results indicate that both severe and moderate maternal vitamin B12 restrictions were associated with accelerated catch-up growth, increased body fat percentage, visceral adiposity, dyslipidemia, fasting hyperglycemia and insulin resistance in the F1 offspring. Inflammation, increased glucocorticoid and oxidative stress and poor antioxidant defence probably underlie these adverse effects. Rehabilitation from parturition but not weaning was beneficial in delaying the onset of the adverse outcomes in the offspring. © 2016 BioFactors, 43(3):400-414, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

  12. EFICIENTIZAREA OBŢINERII SEDIMENTELOR FURAJERE B12 -VITAMINIZATE DIN APE REZIDUALE AGROINDUSTRIALE: 2. MODIFICĂRI ALE UTILAJULUI

    Directory of Open Access Journals (Sweden)

    Victor COVALIOV

    2017-03-01

    Full Text Available Prin modificări constructive ale dispozitivelor bioreactorului şi soluţii noi: separarea zonelor acetogenă şi meta­no­genă în interiorul bioreactorului, recircularea CO2 şi suplimentarea acestuia cu H2 exogen, adsorbţia vitaminei B12 din lichidul postfermentare cu diatomită s-a obţinut ridicarea conţinutului de vitamina B12 în sedimentele epurării fermentativ–metanogene (anaerobe a borhotului postalcoolic până la calitatea de con­centrat furajer B12-vitaminizat, concomitent cu intensificarea producerii biometanului, ca elemente ale ridicării eficienţei ecologo-economice a epurării anaerobe a borhotului.MORE EFFICIENT PRODUCITON OF VITAMINIZED FORAGE SLUDGE CONTAINING B12 FROM AGRO-INDUSTRIAL WASTES: 2. EQUIPMENT MODIFICAITON The increase in vitamin B12 contents in the sludge was obtained resulted from the methanogenic (anaerobic digestion of post-distillery vinasse, through the design modifications of bioreactor interiour, CO2 re-circulation and its interaction with additionally dosed exogenic hydrogen. Vitamin B12 was further adsorbed on diatomite surface from the post-digestion liquid, which made it possible to produce the cattle forage concentrate enriched with vitamin B12. At the same time, biomethane production was intensified, being the element of ecologically-economic efficiency of anaerobic treatment of vinasse (agro-industrial waste.

  13. Calcium absorption

    International Nuclear Information System (INIS)

    Carlmark, B.; Reizenstein, P.; Dudley, R.A.

    1976-01-01

    The methods most commonly used to measure the absorption and retention of orally administered calcium are reviewed. Nearly all make use of calcium radioisotopes. The magnitude of calcium absorption and retention depends upon the chemical form and amount of calcium administered, and the clinical and nutritional status of the subject; these influences are briefly surveyed. (author)

  14. Simulation of a combined heating, cooling and domestic hot water system based on ground source absorption heat pump

    International Nuclear Information System (INIS)

    Wu, Wei; You, Tian; Wang, Baolong; Shi, Wenxing; Li, Xianting

    2014-01-01

    Highlights: • A combined heating/cooling/DHW system based on GSAHP is proposed in cold regions. • The soil imbalance is effectively reduced and soil temperature can be kept stable. • 20% and 15% of condensation/absorption heat is recovered by GSAHP to produce DHW. • The combined system can improve the primary energy efficiency by 23.6% and 44.4%. - Abstract: The amount of energy used for heating and domestic hot water (DHW) is very high and will keep increasing. The conventional ground source electrical heat pump used in heating-dominated buildings has the problems of thermal imbalance, decrease of soil temperature, and deterioration of heating performance. Ground source absorption heat pump (GSAHP) is advantageous in both imbalance reduction and primary energy efficiency (PEE) improvement; however, the imbalance is still unacceptable in the warmer parts of cold regions. A combined heating/cooling/DHW (HCD) system based on GSAHP is proposed to overcome this problem. The GSAHPs using generator absorber heat exchange (GAX) and single-effect (SE) cycles are simulated to obtain the performance under various working conditions. Different HCD systems in Beijing and Shenyang are simulated comparatively in TRNSYS, based on which the thermal imbalance, soil temperature, heat recovery, and energy efficiency are analyzed. Results show that GSAHP–GAX–HCD is suitable for Beijing and GSAHP–SE–HCD is suitable for Shenyang. The imbalance ratio can be reduced to −14.8% in Beijing and to 6.0% in Shenyang with an annual soil temperature variation of only 0.5 °C and 0.1 °C. Furthermore, about 20% and 15% of the total condensation/absorption heat is recovered to produce DHW, and the PEE can reach 1.516 in Beijing and 1.163 in Shenyang. The combined HCD systems can achieve a PEE improvement of 23.6% and 44.4% compared with the normal heating/cooling systems

  15. Optical components based on two-photon absorption process in functionalized polymers

    International Nuclear Information System (INIS)

    Klein, S.; Barsella, A.; Taupier, G.; Stortz, V.; Fort, A.; Dorkenoo, K.D.

    2006-01-01

    We report on the fabrication of basic elements needed in optical circuits in a photopolymerizable resin, using a two-photon absorption (TPA) process to perform a selective polymerization. By taking advantage of the high spatial selectivity of the TPA approach, we can control the value of the local index of refraction in the material and realize permanent optical pathways in the bulk of photopolymerizable matrices. The computer-controlled design of such pathways allows creating optical circuits. As an example of application, optical fibers separated by millimetric distances and placed in arbitrary positions have been connected with moderate losses. Moreover, active components, such as electro-optical Mach-Zehnder interferometers, can be fabricated using photopolymers functionalized with non-linear optical chromophores, in order to be integrated in micro-optical circuits

  16. Hydrogen absorption study of Ti-based alloys performed by melt-spinning

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, R.M.; Lemus, L.F.; Santos, D.S. dos, E-mail: rafaella@metalmat.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEMM/COPPEP/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Metalurgica e de Materiais

    2013-11-01

    The hydrogen absorption and desorption of Ti{sub 53}Zr{sub 27}Ni{sub 20} icosahedral quasicrystal (ICQ) and Ti{sub 50}Ni{sub 50} shape memory alloy (SMA) melt-spun ribbons was studied. Samples were exposed to hydrogen gas at 623 K and 4 MPa for 1000 minutes. The total capacity of hydrogen obtained for Ti{sub 53}Zr{sub 27}Ni{sub 20} and Ti{sub 50}Ni{sub 50} was 3.2 and 2.4 wt. % respectively. The Thermal Desorption Spectrometry (TDS) of the hydrogenated alloys shows that both alloys start to desorb hydrogen around 750 K. X-ray diffraction (XRD) patterns, performed after hydrogenation, indicate a complete amorphization of the Ti{sub 53}Zr{sub 27}Ni{sub 20} i-phase alloy, while the Ti{sub 50}Ni{sub 50} alloy remained crystalline after hydride formation. (author)

  17. Comparison of directly compressed vitamin B12 tablets prepared from micronized rotary-spun microfibers and cast films.

    Science.gov (United States)

    Sebe, István; Bodai, Zsolt; Eke, Zsuzsanna; Kállai-Szabó, Barnabás; Szabó, Péter; Zelkó, Romána

    2015-01-01

    Fiber-based dosage forms are potential alternatives of conventional dosage forms from the point of the improved extent and rate of drug dissolution. Rotary-spun polymer fibers and cast films were prepared and micronized in order to direct compress after homogenization with tabletting excipients. Particle size distribution of powder mixtures of micronized fibers and films homogenized with tabletting excipients were determined by laser scattering particle size distribution analyzer. Powder rheological behavior of the mixtures containing micronized fibers and cast films was also compared. Positron annihilation lifetime spectroscopy was applied for the microstructural characterization of micronized fibers and films. The water-soluble vitamin B12 release from the compressed tablets was determined. It was confirmed that the rotary spinning method resulted in homogeneous supramolecularly ordered powder mixture, which was successfully compressed after ho