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Sample records for naja naja kaouthia

  1. Efficacy of tannins from Mimosa pudica and tannic acid in neutralizing cobra (Naja kaouthia venom

    FY Sia

    2011-01-01

    Full Text Available In the present study, the effectiveness of Mimosa pudica tannins (MPT in neutralizing the lethality of Naja kaouthia venom was compared with commercially derived tannins. Preincubation of MPT with N. kaouthia venom maintained 100% survival of mice after 24 hours. The mouse group in which there was no preincubation, no protection against the effects of the venom was observed. M. pudica tannin was found to be more effective in neutralizing the lethality of N. kaouthia venom when compared to commercial tannic acid. Two protein spots were missing in the two-dimensional gel electrophoresis (2-DE of the MPT treated mouse indicating the down-regulation of venom proteins. The results from this study indicated that tannins obtained from M. pudica are better than tannic acid in neutralizing the lethality of N. kaouthia venom in vitro. However, further investigations are required to establish that M. pudica has potential for treating N. kaouthia snakebites.

  2. Analysis of the efficacy of Taiwanese freeze-dried neurotoxic antivenom against Naja kaouthia, Naja siamensis and Ophiophagus hannah through proteomics and animal model approaches.

    Liu, Chien-Chun; You, Chen-Hsien; Wang, Po-Jung; Yu, Jau-Song; Huang, Guo-Jen; Liu, Chien-Hsin; Hsieh, Wen-Chin; Lin, Chih-Chuan

    2017-12-01

    In Southeast Asia, envenoming resulting from cobra snakebites is an important public health issue in many regions, and antivenom therapy is the standard treatment for the snakebite. Because these cobras share a close evolutionary history, the amino acid sequences of major venom components in different snakes are very similar. Therefore, either monovalent or polyvalent antivenoms may offer paraspecific protection against envenomation of humans by several different snakes. In Taiwan, a bivalent antivenom-freeze-dried neurotoxic antivenom (FNAV)-against Bungarus multicinctus and Naja atra is available. However, whether this antivenom is also capable of neutralizing the venom of other species of snakes is not known. Here, to expand the clinical application of Taiwanese FNAV, we used an animal model to evaluate the neutralizing ability of FNAV against the venoms of three common snakes in Southeast Asia, including two 'true' cobras Naja kaouthia (Thailand) and Naja siamensis (Thailand), and the king cobra Ophiophagus hannah (Indonesia). We further applied mass spectrometry (MS)-based proteomic techniques to characterize venom proteomes and identify FNAV-recognizable antigens in the venoms of these Asian snakes. Neutralization assays in a mouse model showed that FNAV effectively neutralized the lethality of N. kaouthia and N. siamensis venoms, but not O. hannah venom. MS-based venom protein identification results further revealed that FNAV strongly recognized three-finger toxin and phospholipase A2, the major protein components of N. kaouthia and N. siamensis venoms. The characterization of venom proteomes and identification of FNAV-recognizable venom antigens may help researchers to further develop more effective antivenom designed to block the toxicity of dominant toxic proteins, with the ultimate goal of achieving broadly therapeutic effects against these cobra snakebites.

  3. Venomics, lethality and neutralization of Naja kaouthia (monocled cobra) venoms from three different geographical regions of Southeast Asia.

    Tan, Kae Yi; Tan, Choo Hock; Fung, Shin Yee; Tan, Nget Hong

    2015-04-29

    Previous studies showed that venoms of the monocled cobra, Naja kaouthia from Thailand and Malaysia are substantially different in their median lethal doses. The intraspecific venom variations of N. kaouthia, however, have not been fully elucidated. Here we investigated the venom proteomes of N. kaouthia from Malaysia (NK-M), Thailand (NK-T) and Vietnam (NK-V) through reverse-phase HPLC, SDS-PAGE and tandem mass spectrometry. The venom proteins comprise 13 toxin families, with three-finger toxins being the most abundant (63-77%) and the most varied (11-18 isoforms) among the three populations. NK-T has the highest content of neurotoxins (50%, predominantly long neurotoxins), followed by NK-V (29%, predominantly weak neurotoxins and some short neurotoxins), while NK-M has the least (18%, some weak neurotoxins but less short and long neurotoxins). On the other hand, cytotoxins constitute the main bulk of toxins in NK-M and NK-V venoms (up to 45% each), but less in NK-T venom (27%). The three venoms show different lethal potencies that generally reflect the proteomic findings. Despite the proteomic variations, the use of Thai monovalent and Neuro polyvalent antivenoms for N. kaouthia envenomation in the three regions is appropriate as the different venoms were neutralized by the antivenoms albeit at different degrees of effectiveness. Biogeographical variations were observed in the venom proteome of monocled cobra (Naja kaouthia) from Malaysia, Thailand and Vietnam. The Thai N. kaouthia venom is particularly rich in long neurotoxins, while the Malaysian and Vietnamese specimens were predominated with cytotoxins. The differentially expressed toxin profile accounts for the discrepancy in the lethal dose of the venom from different populations. Commercially available Thai antivenoms (monovalent and polyvalent) were able to neutralize the three venoms at different effective doses, hence supporting their uses in the three regions. While dose adjustment according to

  4. Daboia russellii and Naja kaouthia venom neutralization by lupeol acetate isolated from the root extract of Indian sarsaparilla Hemidesmus indicus R.Br.

    Chatterjee, Ipshita; Chakravarty, A K; Gomes, A

    2006-06-15

    The present study reports the isolation and purification of lupeol acetate from the methanolic root extract of Indian medicinal plant Hemidesmus indicus (L.) R.Br. (family: Asclepiadaceae) which could neutralize venom induced action of Daboia russellii and Naja kaouthia on experimental animals. Lupeol acetate could significantly neutralize lethality, haemorrhage, defibrinogenation, edema, PLA(2) activity induced by Daboia russellii venom. It also neutralized Naja kaouthia venom induced lethality, cardiotoxicity, neurotoxicity and respiratory changes in experimental animals. Lupeol acetate potentiated the protection by snake venom antiserum action against Daboia russellii venom induced lethality in male albino mice. Venom induced changes in lipid peroxidation and super oxide dismutase activity was antagonized by lupeol acetate. Snake venom neutralization by lupeol acetate and its possible mechanism of action has been discussed.

  5. (Naja kaouthia) venom

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  6. Ophiophagus hannah Venom: Proteome, Components Bound by Naja kaouthia Antivenin and Neutralization by N. kaouthia Neurotoxin-Specific Human ScFv

    Witchuda Danpaiboon

    2014-05-01

    Full Text Available Venomous snakebites are an important health problem in tropical and subtropical countries. King cobra (Ophiophagus hannah is the largest venomous snake found in South and Southeast Asia. In this study, the O. hannah venom proteome and the venom components cross-reactive to N. kaouthia monospecific antivenin were studied. O. hannah venom consisted of 14 different protein families, including three finger toxins, phospholipases, cysteine-rich secretory proteins, cobra venom factor, muscarinic toxin, L-amino acid oxidase, hypothetical proteins, low cysteine protein, phosphodiesterase, proteases, vespryn toxin, Kunitz, growth factor activators and others (coagulation factor, endonuclease, 5’-nucleotidase. N. kaouthia antivenin recognized several functionally different O. hannah venom proteins and mediated paratherapeutic efficacy by rescuing the O. hannah envenomed mice from lethality. An engineered human ScFv specific to N. kaouthia long neurotoxin (NkLN-HuScFv cross-neutralized the O. hannah venom and extricated the O. hannah envenomed mice from death in a dose escalation manner. Homology modeling and molecular docking revealed that NkLN-HuScFv interacted with residues in loops 2 and 3 of the neurotoxins of both snake species, which are important for neuronal acetylcholine receptor binding. The data of this study are useful for snakebite treatment when and where the polyspecific antivenin is not available. Because the supply of horse-derived antivenin is limited and the preparation may cause some adverse effects in recipients, a cocktail of recombinant human ScFvs for various toxic venom components shared by different venomous snakes, exemplified by the in vitro produced NkLN-HuScFv in this study, should contribute to a possible future route for an improved alternative to the antivenins.

  7. Ophiophagus hannah venom: proteome, components bound by Naja kaouthia antivenin and neutralization by N. kaouthia neurotoxin-specific human ScFv.

    Danpaiboon, Witchuda; Reamtong, Onrapak; Sookrung, Nitat; Seesuay, Watee; Sakolvaree, Yuwaporn; Thanongsaksrikul, Jeeraphong; Dong-din-on, Fonthip; Srimanote, Potjanee; Thueng-in, Kanyarat; Chaicumpa, Wanpen

    2014-05-13

    Venomous snakebites are an important health problem in tropical and subtropical countries. King cobra (Ophiophagus hannah) is the largest venomous snake found in South and Southeast Asia. In this study, the O. hannah venom proteome and the venom components cross-reactive to N. kaouthia monospecific antivenin were studied. O. hannah venom consisted of 14 different protein families, including three finger toxins, phospholipases, cysteine-rich secretory proteins, cobra venom factor, muscarinic toxin, L-amino acid oxidase, hypothetical proteins, low cysteine protein, phosphodiesterase, proteases, vespryn toxin, Kunitz, growth factor activators and others (coagulation factor, endonuclease, 5'-nucleotidase). N. kaouthia antivenin recognized several functionally different O. hannah venom proteins and mediated paratherapeutic efficacy by rescuing the O. hannah envenomed mice from lethality. An engineered human ScFv specific to N. kaouthia long neurotoxin (NkLN-HuScFv) cross-neutralized the O. hannah venom and extricated the O. hannah envenomed mice from death in a dose escalation manner. Homology modeling and molecular docking revealed that NkLN-HuScFv interacted with residues in loops 2 and 3 of the neurotoxins of both snake species, which are important for neuronal acetylcholine receptor binding. The data of this study are useful for snakebite treatment when and where the polyspecific antivenin is not available. Because the supply of horse-derived antivenin is limited and the preparation may cause some adverse effects in recipients, a cocktail of recombinant human ScFvs for various toxic venom components shared by different venomous snakes, exemplified by the in vitro produced NkLN-HuScFv in this study, should contribute to a possible future route for an improved alternative to the antivenins.

  8. Differential Effects of Naja naja atra Venom on Immune Activity

    Jian-Qun Kou

    2014-01-01

    Full Text Available Previous studies reported that Naja naja atra venom (NNAV inhibited inflammation and adjuvant arthritis. Here we investigated the role of NNAV in regulation of immune responses in mice. Oral administration of NNAV to normal mice showed significant increase in natural killer cell activity, B lymphocyte proliferation stimulated by lipopolysaccharides, and antibody production in response to sheep red blood cells. Meanwhile, NNAV markedly decreased T lymphocyte proliferation stimulated by concanavalin A, arrested the cell cycle at G0/G1 phase, and suppressed CD4 and CD8 T cell divisions. Furthermore, NNAV inhibited the dinitrofluorobenzene-induced delayed-type hypersensitivity reaction. This modulation of immune responses may be partly attributed to the selective increase in Th1 and Th2 cytokines (IFN-γ, IL-4 secretion and inhibition of Th17 cytokine (IL-17 production. In dexamethasone-induced immunosuppressed mice, NNAV restored the concentration of serum IgG and IgM, while decreasing the percentage of CD4 and CD8 T-cell subsets. These results indicate that NNAV enhances the innate and humoral immune responses while inhibiting CD4 Th17 and CD8 T cell actions, suggesting that NNAV could be a potential therapeutic agent for autoimmune diseases.

  9. Irradiated cobra (Naja naja) venom for biomedical applications

    Kankonkar, S.R.; Kankonkar, R.C.; Gaitonde, B.B.

    1975-01-01

    Ionizing radiation is known to cause damage to proteins in aqueous solutions in a selective manner, thereby producing remarkable changes in their properties. Since venoms are very rich in proteins, it was felt that they would also show such changes upon irradiation. It was of interest to know if one could get rid of the toxicity and retain the immunogenicity of the venom by suitable choice of radiation dose and strength of venom solution. If so, the method could be profitably exploited for the rapid preparation of venom toxoid and this could be expected to have many applications in the biological sciences. Accordingly, laboratory investigations were undertaken on the effect of gamma radiation on cobra (Naja naja) venom. To avoid drastic changes, solutions of cobra venom having low protein content were irradiated with gamma radiation from a cobalt-60 source. The results obtained with 0.01 to 1.0% venom solutions are found to be encouraging. The solutions did not manifest any toxicity in mice. For the immunogenicity test, guinea pigs were immunized with varying doses of the irradiated cobra venom and the immunized guinea pigs were found to survive when challenged with as big a dose as 10 MLD (i.e. minimum lethal dose, approximately 1 mg). The paper describes the experimental details and the results of the observations. (author)

  10. Antitoxin activity of Mimosa pudica root extracts against Naja naja and Bangarus caerulus venoms

    Subramani Meenatchisundaram

    2009-06-01

    Full Text Available Aqueous extract of dried roots of Mimosa pudica was tested for inhibitory activity on lethality, phospholipase activity, edema forming activity, fibrinolytic activity and hemorrhagic activity of Naja naja and Bangarus caerulus venoms. The aqueous extract displayed a significant inhibitory effect on the lethality, phospholipase activity, edema forming activity, fibrinolytic activity and hemorrhagic activity. About 0.14 mg and 0.16 mg of M. pudica extracts were able to completely neutralize the lethal activity of 2LD50 of Naja naja and Bangarus caerulus venoms respectively. The present finding suggests that aqueous extract of M. pudica root possesses compounds, which inhibit the activity of Naja naja and Bangarus caerulus venoms.

  11. Antitoxin activity of Mimosa pudica root extracts against Naja naja and Bangarus caerulus venoms

    Subramani Meenatchisundaram, Selvin Priyagrace, Ramasamy Vijayaraghavan, Ambikapathi Velmurugan, Govindarajan Parameswari, Antonysamy Michael

    2009-12-01

    Full Text Available Aqueous extract of dried roots of Mimosa pudica was tested for inhibitory activity on lethality, phospholipase activity, edema forming activity, fibrinolytic activity and hemorrhagic activity of Naja naja and Bangarus caerulus venoms. The aqueous extract displayed a significant inhibitory effect on the lethality, phospholipase activity, edema forming activity, fibrinolytic activity and hemorrhagic activity. About 0.14 mg and 0.16 mg of M. pudica extracts were able to completely neutralize the lethal activity of 2LD50 of Naja naja and Bangarus caerulus venoms respectively. The present finding suggests that aqueous extract of M. pudica root possesses compounds, which inhibit the activity of Naja naja and Bangarus caerulus venoms.

  12. Two acidic, anticoagulant PLA2 isoenzymes purified from the venom of monocled cobra Naja kaouthia exhibit different potency to inhibit thrombin and factor Xa via phospholipids independent, non-enzymatic mechanism.

    Ashis K Mukherjee

    Full Text Available The monocled cobra (Naja kaouthia is responsible for snakebite fatality in Indian subcontinent and in south-western China. Phospholipase A2 (PLA2; EC 3.1.1.4 is one of the toxic components of snake venom. The present study explores the mechanism and rationale(s for the differences in anticoagulant potency of two acidic PLA2 isoenzymes, Nk-PLA2α (13463.91 Da and Nk-PLA2β (13282.38 Da purified from the venom of N. kaouthia.By LC-MS/MS analysis, these PLA2s showed highest similarity (23.5% sequence coverage with PLA2 III isolated from monocled cobra venom. The catalytic activity of Nk-PLA2β exceeds that of Nk-PLA2α. Heparin differentially regulated the catalytic and anticoagulant activities of these Nk-PLA2 isoenzymes. The anticoagulant potency of Nk-PLA2α was comparable to commercial anticoagulants warfarin, and heparin/antithrombin-III albeit Nk-PLA2β demonstrated highest anticoagulant activity. The anticoagulant action of these PLA2s was partially contributed by a small but specific hydrolysis of plasma phospholipids. The strong anticoagulant effect of Nk-PLA2α and Nk-PLA2β was achieved via preferential, non-enzymatic inhibition of FXa (Ki = 43 nM and thrombin (Ki = 8.3 nM, respectively. Kinetics study suggests that the Nk-PLA2 isoenzymes inhibit their "pharmacological target(s" by uncompetitive mechanism without the requirement of phospholipids/Ca(2+. The anticoagulant potency of Nk-PLA2β which is higher than that of Nk-PLA2α is corroborated by its superior catalytic activity, its higher capacity for binding to phosphatidylcholine, and its greater strength of thrombin inhibition. These PLA2 isoenzymes thus have evolved to affect haemostasis by different mechanisms. The Nk-PLA2β partially inhibited the thrombin-induced aggregation of mammalian platelets suggesting its therapeutic application in the prevention of unwanted clot formation.In order to develop peptide-based superior anticoagulant therapeutics, future application of Nk-PLA2

  13. Antitoxin activity of aqueous extract of Cyclea peltata root against Naja naja venom

    Sivaraman, Thulasi; Sreedevi, N. S.; Meenatchisundaram, S.; Vadivelan, R.

    2017-01-01

    OBJECTIVES: Snakebites are a significant and severe global health problem. Till date, anti-snake venom serum is the only beneficial remedy existing on treating the snakebite victims. As antivenom was reported to induce early or late adverse reactions to human beings, snake venom neutralizing potential for Cyclea peltata root extract was tested for the present research by ex vivo and in vivo approaches on Naja naja toxin. MATERIALS AND METHODS: Ex vivo evaluation of venom toxicity and neutrali...

  14. Antitoxin activity of aqueous extract of Cyclea peltata root against Naja naja venom.

    Sivaraman, Thulasi; Sreedevi, N S; Meenatchisundaram, S; Vadivelan, R

    2017-01-01

    Snakebites are a significant and severe global health problem. Till date, anti-snake venom serum is the only beneficial remedy existing on treating the snakebite victims. As antivenom was reported to induce early or late adverse reactions to human beings, snake venom neutralizing potential for Cyclea peltata root extract was tested for the present research by ex vivo and in vivo approaches on Naja naja toxin. Ex vivo evaluation of venom toxicity and neutralization assays was carried out. The root extracts from C. peltata were used to evaluate the Ex vivo neutralization tests such as acetylcholinesterase, protease, direct hemolysis assay, phospholipase activity, and procoagulant activity. Gas chromatography-mass spectrometry (GC-MS) analysis from root extracts of C. peltata was done to investigate the bioactive compounds. The in vivo calculation of venom toxicity (LD 50 ) of N. naja venom remained to be 0.301 μg. C. peltata root extracts were efficiently deactivated the venom lethality, and effective dose (ED 50 ) remained to be 7.24 mg/3LD 50 of N. naja venom. C. peltata root extract was found effective in counteracting all the lethal effects of venom. GC-MS analysis of the plant extract revealed the presence of antivenom compounds such as tetradecanoic and octadecadienoic acid which have neutralizing properties on N. naja venom. The result from the ex vivo and in vivo analysis indicates that C. peltata plant root extract possesses significant compounds such as tetradecanoic acid hexadecanoic acid, heptadecanoic acid, and octadecadienoic acid which can counteract the toxins present in N. naja .

  15. Anti-Inflammatory and Immune Regulatory Actions of Naja naja atra Venom

    Shu-Zhi Wang

    2018-02-01

    Full Text Available Naja naja atra venom (NNAV is composed of various proteins, peptides, and enzymes with different biological and pharmacological functions. A number of previous studies have reported that NNAV exerts potent analgesic effects on various animal models of pain. The clinical studies using whole venom or active components have confirmed that NNAV is an effective and safe medicine for treatment of chronic pain. Furthermore, recent studies have demonstrated that NNAV has anti-inflammatory and immune regulatory actions in vitro and in vivo. In this review article, we summarize recent studies of NNAV and its components on inflammation and immunity. The main new findings in NNAV research show that it may enhance innate and humoral immune responses while suppressing T lymphocytes-mediated cellular immunity, thus suggesting that NNAV and its active components may have therapeutic values in the treatment of inflammatory and autoimmune diseases.

  16. Hemolitic action of Naja naja atra cardiotoxin on erythrocytes from different animals

    J. C. Troiano

    2006-01-01

    Full Text Available A comparative study on the sensitivity of erythrocytes from different vertebrate species (avian, mammalian and reptilian to the hemolytic action caused by cardiotoxin isolated from Naja naja atra venom was carried out. Cardiotoxin was able to induce direct hemolysis in washed erythrocytes from several animals, except for llama. The EC50 values from hemolysis of the most sensitive (cat and the most resistant (snake animal varied approximately tenfold. According to the cell behavior, it was possible to characterize four types of behavior: The first was observed in cat, horse and human cells; the second in rat, rabbit and dog erythrocytes; and the third only in llama erythrocytes, which were resistant to cardiotoxin concentrations up to 300 µg/ml. Finally, avian and reptilian erythrocytes were more resistant to cardiotoxin III-induced hemolysis than those of the mammalian species.

  17. Production of effective antivenin to treat cobra snake (Naja naja oxiana envenoming

    Akbari, A.

    2010-01-01

    Full Text Available Conventional treatment of Naja naja oxiana (NNO envenoming requires large volumes of equine antivenin raised against NNO crude venom. The poor efficiency of this antivenin is assumed to be due to the high molecular weight non-toxic proteins, a strong immunogen, present in the crude venom. These proteins cause depression of antibody formation against the low molecular weight toxic components of venom. In the present study the low molecular weight lethal components were isolated from crude venom of NNO venom by sephadex G50 get filtration chromatography. A sera was prepared by immunizing horses with toxic fraction. One milliliter of this serum neutralized 1.8mg of NNO crude venom. This high titer antivenin is thus 2.2 times more potent than the sera obtained against NNO crude venom.

  18. Naja naja atra venom ameliorates pulmonary fibrosis by inhibiting inflammatory response and oxidative stress.

    Cui, Kui; Kou, Jian-Qun; Gu, Jin-Hua; Han, Rong; Wang, Guanghui; Zhen, Xuechu; Qin, Zheng-Hong

    2014-12-02

    Naja naja atra venom (NNAV) displays diverse pharmacological actions including analgesia, anti-inflammation and immune regulation.In this study, we investigated the effects of NNAV on pulmonary fibrosis and its mechanisms of action. To determine if Naja naja atra venom (NNAV) can produce beneficial effects on pulmonary fibrosis, two marine models of pulmonary fibrosis were produced with bleomycin (BLM) and lipopolysaccharide (LPS). NNAV (30, 90, 270 μg/kg) was orally administered once a day started five days before BLM and LPS until to the end of experiment. The effects of NNAV treatment on pulmonary injury were evaluated with arterial blood gas analysis, hydroxyproline (HYP) content assessment and HE/Masson staining. The effects of NNAV treatment on inflammatory related cytokines, fibrosis related TGF-β/Smad signaling pathway and oxidative stress were examined. The results showed that NNAV improved the lung gas-exchange function and attenuated the fibrotic lesions in lung. NNAV decreased IL-1β and TNF-α levels in serum in both pulmonary fibrosis models. NNAV inhibited the activation of NF-κB in LPS-induced and TGF-β/Smad pathway in BLM-induced pulmonary fibrosis. Additionally, NNAV also increased the levels of SOD and GSH and reduced the levels of MDA in BLM-induced pulmonary fibrosis model. The present study indicates that NNAV attenuates LPS- and BLM-induced lung fibrosis. Its mechanisms of action are associated with inhibiting inflammatory response and oxidative stress. The study suggests that NNAV might be a potential therapeutic drug for treatment of pulmonary fibrosis.

  19. Inhibitory potential of important phytochemicals from Pergularia daemia (Forsk. chiov., on snake venom (Naja naja

    S.T.V. Raghavamma

    2016-06-01

    Full Text Available Pergularia daemia (Forsk. chiov., is a milk weed of Asclepiadaceae family. In the present study β-sitosterol, β-amyrin, α-amyrin and lupeol were identified in the leaf by GC–MS. Molecular docking studies were performed to evaluate their activities on phospholipase A2 (PLA2 and l-amino acid oxidase enzymes which constituted a rich source in snake venoms (Naja naja. Snake venom Phospholipase A2 with PDB code 1A3D devoid of co-crystallized ligand was extracted from Protein Data Bank. Using Molegro Virtual Docker two cavities are formed by cocrystallization. l-Amino acid oxidase (PDB code 4E0V was a receptor model with a co-crystallized ligand FAD. Among the phytochemicals analysed, β-sitosterol displayed high affinity of binding to the active site regions of phospholipase A2 and l-amino acid oxidase, respectively. The affinity of binding was −125.939 and −157.521 kcal/mole identified by gold scores. α-Amyrin and β-amyrin had two hydrogen bond interactions with PLA2. Hence this study suggests that β-sitosterol identified in P. daemia can antagonize PLA2 and LAAO activities and forms a theoretical basis for the folk use of the plant against snake venom.

  20. Suppression of Inflammation and Arthritis by Orally Administrated Cardiotoxin from Naja naja atra

    Cao-Xin Chen

    2015-01-01

    Full Text Available Cardiotoxin (CTX from Naja naja atra venom (NNAV reportedly had analgesic effect in animal models but its role in inflammation and arthritis was unknown. In this study, we investigated the analgesic, anti-inflammatory, and antiarthritic actions of orally administered CTX-IV isolated from NNAV on rodent models of inflammation and adjuvant arthritis. CTX had significant anti-inflammatory effects in models of egg white induced nonspecific inflammation, filter paper induced rat granuloma formation, and capillary osmosis tests. CTX significantly reduced the swelling of paw induced by egg white, the inflammatory exudation, and the formation of granulomas. CTX reduced the swelling of paw, the AA clinical scores, and pathological alterations of joint. CTX significantly decreased the number of the CD4 T cells and inhibited the expression of relevant proinflammatory cytokines IL-17 and IL-6. CTX significantly inhibited the secretion of proinflammatory cytokine IL-6 and reduced the level of p-STAT3 in FLS. These results suggest that CTX inhibits inflammation and inflammatory pain and adjuvant-induced arthritis. CTX may be a novel therapeutic drug for treatment of arthritis.

  1. Culturable Aerobic and Facultative Anaerobic Intestinal Bacterial Flora of Black Cobra (Naja naja karachiensis) in Southern Pakistan

    Iqbal, Junaid; Sagheer, Mehwish; Tabassum, Nazneen; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2014-01-01

    Using morphological analysis and biochemical testing, here for the first time, we determined the culturable gut bacterial flora (aerobes and facultative anaerobes) in the venomous Black Cobra (Naja naja karachiensis) from South Asia. The findings revealed that these snakes inhabit potentially pathogenic bacteria including Serratia marcescens, Pseudomonas aeruginosa, Shewanella putrefaciens, Aeromonas hydrophila, Salmonella sp., Moraxella sp., Bacillus sp., Ochrobactrum anthropi, and Providencia rettgeri. These findings are of concern, as injury from snake bite can result in wound infections and tissue necrosis leading to sepsis/necrotizing fasciitis and/or expose consumers of snake meat/medicine in the community to infections. PMID:25002979

  2. Isolation of a cytolytic component from naja nigricollis nigricollis ...

    It is partially pure as indicated by SDS-PAGE, with molecular weight approximately 10 kDa. It has no protease or phospholipase activity. It is a ... Small doses of VIb induced lysis in breast, colon and hepatocellular carcinomas cell lines in tissue culture plates. Keywords: Naja cytotoxin, Hemolytic, Cytolysis, malignant cells ...

  3. Antivenom potential of ethanolic extract of Cordia macleodii bark against Naja venom

    Pranay Soni; Surendra H. Bodakhe

    2014-01-01

    Objective: To evaluate the antivenom potential of ethanolic extract of bark of Cordia macleodii against Naja venom induced pharmacological effects such as lethality, hemorrhagic lesion, necrotizing lesion, edema, cardiotoxicity and neurotoxicity. Methods: Wistar strain rats were challenged with Naja venom and treated with the ethanolic extract of Cordia macleodii bark. The effectiveness of the extract to neutralize the lethalities of Naja venom was investigated as recommended by WHO. Re...

  4. In vivo studies on detoxifying actions of aqueous bark extract of Prosopis cineraria against crude venom from Indian cobra (Naja naja)

    Thirunavukkarasu Sivaraman; Sivarathri Siva Rajesh; Veerayan Elango

    2013-01-01

    Detoxification effect of aqueous, methanol and petroleum ether extracts of medicinal plants such as Aristolochia bracteolata, Mucuna pruriens, Prosopis cineraria and Rauvolfia tetraphylla was systematically screened against lethality of crude venom of Naja naja using Swiss albino mice as animal models. We have herein demonstrated that aqueous bark extract of P. cineraria has substantial anti-venom potential vis-à-vis other extracts used in the present study. The aqueous extract at the dose of...

  5. Assessment of the toxicity level of gamma-irradiated snake (Naja naja oxiana) venom by photoacoustic spectroscopy

    Vidyasagar, P.B.; Pal, Saumen

    1991-01-01

    Immunization is the only answer to the challenge of the diseases for which it is extremely difficult to institute timely and proper treatment following the inset. Various antigenic agents responsible for such diseases are used for the purpose of immunization to overcome this difficulty. To make safe use of the antigens it is required to reduce their toxicity level keeping the antigenicity intact and develop a suitable way to detect it. To ensure this, toxoids are produced from the toxic antigens by using different physical and chemical methods. Snake venoms are some important antigens which deserve more attention to be used for immunization because bites by poisonous snakes require instant treatment which is difficult to install. Toxoids used in the present study were produced by irradiating oxus cobra (Naja naja oxiana) venom under cobalt-60 gamma-ray source. The toxocity level of thus produced venom toxoid was assessed by photoacoustic (PA) spectroscopy. In support of the PA observations, optical absorption and fluorescence spectra of the venom in solution were also studied. Percentile change in PA signal intensity was taken as the parameter for toxocity level which was then correlated to the percentile residual toxocity of the venom obtained by direct method of injecting the venom in mice. Efforts were also made to find out the possible effects of the radiation on the venom. (author). 29 refs., 7 figs

  6. Antivenom potential of ethanolic extract of Cordia macleodii bark against Naja venom.

    Soni, Pranay; Bodakhe, Surendra H

    2014-05-01

    To evaluate the antivenom potential of ethanolic extract of bark of Cordia macleodii against Naja venom induced pharmacological effects such as lethality, hemorrhagic lesion, necrotizing lesion, edema, cardiotoxicity and neurotoxicity. Wistar strain rats were challenged with Naja venom and treated with the ethanolic extract of Cordia macleodii bark. The effectiveness of the extract to neutralize the lethalities of Naja venom was investigated as recommended by WHO. At the dose of 400 and 800 mg/kg ethanolic extract of Cordia macleodii bark significantly inhibited the Naja venom induced lethality, hemorrhagic lesion, necrotizing lesion and edema in rats. Ethanolic extract of Cordia macleodii bark was effective in neutralizing the coagulant and defibrinogenating activity of Naja venom. The cardiotoxic effects in isolated frog heart and neurotoxic activity studies on frog rectus abdominus muscle were also antagonized by ethanolic extract of Cordia macleodii bark. It is concluded that the protective effect of extract of Cordia macleodii against Naja venom poisoning may be mediated by the cardiotonic, proteolysin neutralization, anti-inflammatory, antiserotonic and antihistaminic activity. It is possible that the protective effect may also be due to precipitation of active venom constituents.

  7. Phospholipases A2: enzymatic assay for snake venom (Naja naja karachiensis) with their neutralization by medicinal plants of Pakistan.

    Asad, Muhammad H H B; Durr-E-Sabih; Yaqab, Tahir; Murtaza, Ghulam; Hussain, Muhammad S; Hussain, Muhammad S; Nasir, Muhammad T; Azhar, Saira; Khan, Shujaat A; Hussain, Izhar

    2014-01-01

    Phospholipases A2 (PLA2) are the most lethal and noxious component of Naja naja karachiensis venom. They are engaged to induce severe toxicities after their penetration in victims. Present study was designed to highlight hydrolytic actions of PLA. in an egg yolk mixture and to encounter their deleterious effects via medicinal plants of Pakistan. PLA2 were found to produce free fatty acids in a dose dependent manner. Venom at concentration of 0.1 mg was found to liberate 26.6 pmoles of fatty acids with a decline in pH1 of 0.2 owing to the presence of PLA2 (133 Unit/mg). When quantity of venom was increased up to 8 mg, it caused to release 133 pmoles of free fatty acids with a decrease in 1.0 pH due to abundance in PLA, (665 Unit/mg). The rest of other doses of venom (0.3-4.0 mg) was found to liberate fatty acids between these two upper and lower limits. Twenty eight medicinal plants (0.1-0.6 mg) were tried to abort PLA, hydrolytic action, however, all were found useful (50-100%) against PLA,. Bauhinia variegate L., Citrus limon (L.). Burm.f. Enicostemnma hyssopifolium (Willd.) Verdoorn, Ocimum sanctum. Psoralea corylifolia L. and Stenolobium stans (L.) D. Don were found excellent in switching off 100% phospholipases A, at their lowest concentration (0.1 mg). Three plants extract were found useful only at lower concentration (0.1 mg), however, their higher doses were seemed to aggravate venom response. Eight medicinal plants failed to neutralize PLA, rather their higher doses were found effective. Standard antidote and rest of other plants extract were able to show maximum of 50% efficiencies. Therefore, it is necessary to identify and isolate bioactive constituent(s) from above cited six medicinal plants to eradicate the problem of snake bite in the future.

  8. Delineating residues for haemolytic activities of snake venom cardiotoxin 1 from Naja naja as probed by molecular dynamics simulations and in vitro validations.

    Gorai, Biswajit; Sivaraman, Thirunavukkarasu

    2017-02-01

    Cardiotoxins (CTXs) are single polypeptide chain consisting of 59-62 amino acids with four disulfide bridges and globular proteins of simple β-sheet folds. The CTXs are one of principal toxic components causing haemolysis and damaging various cells and belong to three-finger toxin (TFT) superfamily of snake venoms. However, there is no natural or synthetic small molecular inhibitor to the protein toxins to date. In the present study, modes of interaction of cardiotoxin 1 (CTX1) from Indian cobra (Naja naja) with heterogeneous erythrocyte membrane (EM) model system have been extensively examined by using all-atom molecular dynamics (MD) simulations in near physiological conditions and comprehensive analyses of the MD data revealed two distinct principal regions ('head groove' and 'loop groove') of the protein toxin for establishing structural interactions with the EM system. Moreover, combined analyses of data from high-throughput virtual screening of NCI small molecular database, in vitro haemolytic assays for top-hits of the chemical compounds against crude venom of Naja naja and as well CTXs purified from the venom and pharmacokinetic examinations on the chemical compounds retarding haemolytic activities of CTXs suggested that Etidronic acid and Zoledronic acid are promising prototypic chemical inhibitors to CTXs of snake venoms. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Experimental weed control of Najas marina ssp. intermedia and Elodea nuttallii in lakes using biodegradable jute matting

    Markus A. Hoffmann

    2013-10-01

    Full Text Available The use of jute matting in managing the invasive aquatic macrophyte species Elodea nuttallii (Planch. H. St. John and Najas marina ssp. intermedia (Wolfg. ex Gorski Casper (Najas intermedia was studied in laboratory experiments and field trials. Four German lakes with predominant population of Najas intermedia or Elodea nuttalli were chosen for the experiment and areas between 150 and 300 m² were covered with jute textile. The effect of the matting on the growth of invasive and non-invasive macrophytes was determined through comparison with control transects. Biodegradable jute matting successfully suppressed the invasive macrophyte Najas intermedia and significantly reduced the growth of Elodea nuttalli in lakes. The results indicate that the capability of the matting to inhibit the growth of Elodea nuttallii and Najas intermedia depends on the mesh size of the jute weaving and that environmental conditions can affect its efficiency. Various indigenous species like Charales or Potamogeton pusillus L. were able to grow through the jute fabric and populate the treated areas. Until the end of the vegetation period, none of the invasive species were able to penetrate the covering and establish a stable population; in fact, in the subsequent year the jute matting affected only the spread of Najas intermedia. Jute matting proved to be an easy-to-use and cheap method to control the growth of Elodea nuttallii and Najas intermedia.

  10. Antivenom potential of ethanolic extract of Cordia macleodii bark against Naja venom

    Pranay Soni

    2014-05-01

    Conclusions: It is concluded that the protective effect of extract of Cordia macleodii against Naja venom poisoning may be mediated by the cardiotonic, proteolysin neutralization, anti-inflammatory, antiserotonic and antihistaminic activity. It is possible that the protective effect may also be due to precipitation of active venom constituents.

  11. Effects of light on the growth and photosynthesis of Egeria najas planchon

    Tavechio Washington Luiz Gomes

    2003-01-01

    Full Text Available Photosynthesis and growth of Egeria najas (Hydrocharitaceae from a subtropical reservoir (Itaipu Reservoir, Brazil-Paraguay were measured in response to low light intensities (0-124 µM m-2 s-1 PAR in the laboratory. Photosynthesis approached saturation in the range of light intensities used and light compensation point was reached at ca. 6-22 µM m-2 s-1 PAR, indicating that this species had a low light requirement for growth. Light stimulated shoot and root relative growth rates (RGR but it was not related to ratios between root:shoot RGR. Laboratory observations indicated that (i both shoot and root growth were simultaneously stimulated by light and (ii the low light requirements of E. najas may explain its incidence in the Itaipu Reservoir, where biogenic as well as abiogenic turbidity is high.

  12. In vivo studies on detoxifying actions of aqueous bark extract of Prosopis cineraria against crude venom from Indian cobra (Naja naja

    Thirunavukkarasu Sivaraman

    2013-12-01

    Full Text Available Detoxification effect of aqueous, methanol and petroleum ether extracts of medicinal plants such as Aristolochia bracteolata, Mucuna pruriens, Prosopis cineraria and Rauvolfia tetraphylla was systematically screened against lethality of crude venom of Naja naja using Swiss albino mice as animal models. We have herein demonstrated that aqueous bark extract of P. cineraria has substantial anti-venom potential vis-à-vis other extracts used in the present study. The aqueous extract at the dose of 14 mg/kg b.w. was able to almost completely neutralize the lethal activity of 3LD50 (1.12 mg/kg b.w. of the cobra venom and the extract did not cause any types of adverse side-effects to the animal models. The investigation justifies not only the veraciousness of the extract used by traditional healers of Asian subcontinent as antidotes to snake venoms and also suggests that the aqueous extract should contain specific inhibitors to most principle toxic components of the crude venom.

  13. Estudo do potencial do pacu (Piaractus mesopotamicus como agente de controle biológico de Egeria densa, E. najas e Ceratophyllum demersum Evaluation of the biocontrol potential of pacu (Piaractus mesopotamicus for Egeria densa, E. najas and Ceratophyllum demersum

    D.M.Y. Miyazaki

    2003-01-01

    Full Text Available Visando fornecer subsídios para elaboração de sistema de manejo integrado das grandes massas de plantas daninhas aquáticas submersas em lagos e represas, o presente trabalho teve como objetivo verificar a eficiência do pacu (Piaractus mesopotamicus como agente de controle biológico de Egeria densa, E. najas e Ceratophyllum demersum. As espécies de plantas daninhas foram oferecidas individualmente, duas a duas e as três espécies juntas. Verificou-se que este peixe tem uma eficiência média de controle dessas plantas daninhas variando entre 28 e 100%, podendo eliminar uma massa verde dessas plantas, com a mesma quantidade de seu peso, em sete dias. A eficiência de controle diária aumentou com o tempo de predação. O pacu é mais seletivo para E. densa ou E. najas quando na presença de C. demersum. Não ocorreu alteração na eficiência de controle do pacu sobre E. densa ou E. najas em todos os tratamentos e nos três períodos estudados (três, cinco e sete dias.In order to provide basic information for the establishment of integrated management systems for submersed aquatic weeds in lakes and reservoirs, this research evaluated the efficiency of pacu (Piaractus mesopotamicus as a biocontrol agent of Egeria densa, E. najas and Ceratophyllum demersum. One, two and the three plant species together were offered to the fish. The average efficacy of this fish to control these plants ranged between 28 and 100%. The fish could eliminate a fresh mass of these plants, equivalent to its body weight, in seven days of predation period. Control efficiency increased with increasing duration of the trials. Pacu is more selective in controlling E. densa or E. najas when in the presence of C. demersum. No decreased efficacy was observed in the control of E. densa or E. najas in any of the treatments nor in any of three time periods studied (3, 5, and 7 days.

  14. Novel Naja atra cardiotoxin 1 (CTX-1 derived antimicrobial peptides with broad spectrum activity.

    Andrea Sala

    Full Text Available Naja atra subsp. atra cardiotoxin 1 (CTX-1, produced by Chinese cobra snakes, belonging to Elapidae family, is included in the three-finger toxin family and exerts high cytotoxicity and antimicrobial activity too. Using as template mainly the tip and the subsequent β-strand of the first "finger" of this toxin, different sequences of 20 amino acids linear peptides have been designed in order to avoid toxic effects but to maintain or even strengthen the partial antimicrobial activity already seen for the complete toxin. As a result, the sequence NCP-0 (Naja Cardiotoxin Peptide-0 was designed as ancestor and subsequently 4 other variant sequences of NCP-0 were developed. These synthesized variant sequences have shown microbicidal activity towards a panel of reference and field strains of Gram-positive and Gram-negative bacteria. The sequence named NCP-3, and its variants NCP-3a and NCP-3b, have shown the best antimicrobial activity, together with low cytotoxicity against eukaryotic cells and low hemolytic activity. Bactericidal activity has been demonstrated by minimum bactericidal concentration (MBC assay at values below 10 μg/ml for most of the tested bacterial strains. This potent antimicrobial activity was confirmed even for unicellular fungi Candida albicans, Candida glabrata and Malassezia pachydermatis (MBC 50-6.3 μg/ml, and against the fast-growing mycobacteria Mycobacterium smegmatis and Mycobacterium fortuitum. Moreover, NCP-3 has shown virucidal activity on Bovine Herpesvirus 1 (BoHV1 belonging to Herpesviridae family. The bactericidal activity is maintained even in a high salt concentration medium (125 and 250 mM NaCl and phosphate buffer with 20% Mueller Hinton (MH medium against E. coli, methicillin resistant Staphylococcus aureus (MRSA and Pseudomonas aeruginosa reference strains. Considering these in vitro obtained data, the search for active sequences within proteins presenting an intrinsic microbicidal activity could provide a

  15. Weak toxin WTX from Naja kaouthia cobra venom interacts with both nicotinic and muscarinic acetylcholine receptors

    Mordvintsev, D.Y.; Polyak, Y.L.; Rodionov, D.I.; Jakubík, Jan; Doležal, Vladimír; Karlsson, E.; Tsetlin, V.I.; Utkin, Y.N.

    2009-01-01

    Roč. 276, č. 18 (2009), s. 5065-5075 ISSN 1742-464X R&D Projects: GA MŠk(CZ) LC554; GA AV ČR(CZ) IAA500110703 Institutional research plan: CEZ:AV0Z50110509 Keywords : acetylcholine receptors * allosteric interaction * toxins Subject RIV: ED - Physiology Impact factor: 3.042, year: 2009

  16. Elapid Snake Venom Analyses Show the Specificity of the Peptide Composition at the Level of Genera Naja and Notechis

    Aisha Munawar

    2014-02-01

    Full Text Available Elapid snake venom is a highly valuable, but till now mainly unexplored, source of pharmacologically important peptides. We analyzed the peptide fractions with molecular masses up to 10 kDa of two elapid snake venoms—that of the African cobra, N. m. mossambica (genus Naja, and the Peninsula tiger snake, N. scutatus, from Kangaroo Island (genus Notechis. A combination of chromatographic methods was used to isolate the peptides, which were characterized by combining complimentary mass spectrometric techniques. Comparative analysis of the peptide compositions of two venoms showed specificity at the genus level. Three-finger (3-F cytotoxins, bradykinin-potentiating peptides (BPPs and a bradykinin inhibitor were isolated from the Naja venom. 3-F neurotoxins, Kunitz/basic pancreatic trypsin inhibitor (BPTI-type inhibitors and a natriuretic peptide were identified in the N. venom. The inhibiting activity of the peptides was confirmed in vitro with a selected array of proteases. Cytotoxin 1 (P01467 from the Naja venom might be involved in the disturbance of cellular processes by inhibiting the cell 20S-proteasome. A high degree of similarity between BPPs from elapid and viperid snake venoms was observed, suggesting that these molecules play a key role in snake venoms and also indicating that these peptides were recruited into the snake venom prior to the evolutionary divergence of the snakes.

  17. Comparison of proteomic profiles of the venoms of two of the 'Big Four' snakes of India, the Indian cobra (Naja naja) and the common krait (Bungarus caeruleus), and analyses of their toxins.

    Choudhury, Manisha; McCleary, Ryan J R; Kesherwani, Manish; Kini, R Manjunatha; Velmurugan, Devadasan

    2017-09-01

    Snake venoms are mixtures of biologically-active proteins and peptides, and several studies have described the characteristics of some of these toxins. However, complete proteomic profiling of the venoms of many snake species has not yet been done. The Indian cobra (Naja naja) and common krait (Bungarus caeruleus) are elapid snake species that are among the 'Big Four' responsible for the majority of human snake envenomation cases in India. As understanding the composition and complexity of venoms is necessary for successful treatment of envenomation in humans, we utilized three different proteomic profiling approaches to characterize these venoms: i) one-dimensional SDS-PAGE coupled with in-gel tryptic digestion and electrospray tandem mass spectrometry (ESI-LC-MS/MS) of individual protein bands; ii) in-solution tryptic digestion of crude venoms coupled with ESI-LC-MS/MS; and iii) separation by gel-filtration chromatography coupled with tryptic digestion and ESI-LC-MS/MS of separated fractions. From the generated data, 81 and 46 different proteins were identified from N. naja and B. caeruleus venoms, respectively, belonging to fifteen different protein families. Venoms from both species were found to contain a variety of phospholipases A 2 and three-finger toxins, whereas relatively higher numbers of snake venom metalloproteinases were found in N. naja compared to B. caeruleus venom. The analyses also identified less represented venom proteins including L-amino acid oxidases, cysteine-rich secretory proteins, 5'-nucleotidases and venom nerve growth factors. Further, Kunitz-type serine protease inhibitors, cobra venom factors, phosphodiesterases, vespryns and aminopeptidases were identified in the N. naja venom, while acetylcholinesterases and hyaluronidases were found in the B. caeruleus venom. We further analyzed protein coverage (Lys/Arg rich and poor regions as well as potential glycosylation sites) using in-house software. These studies expand our

  18. Ophidascaris wangi sp. n. and O. najae (Gedoelst, 1916) (Ascaridida: Ascaridoidea) from snakes in China.

    Li, Liang; Guo, Yan-Ning; Li, Jian; Zhang, Lu-Ping

    2014-12-01

    Ophidascaris wangi sp. n. collected from the king rat snake Elaphe carinata (Günther) (Serpentes: Colubridae) in China is described using both light and scanning electron microscopy. The new species differs from its congeners in the presence of narrow lateral alae originating a short distance posterior to the base of the ventrolateral lips, its relatively long oesophagus (3.57-4.54 mm long, representing 6.6-7.6% of body length), its short spicules (1.89-2.14 mm long, representing 3.9-4.3% of body length), the number and arrangement of caudal papillae (49-57 pairs in total, arranged as follows: 43-51 pairs precloacal, 2 pairs joined paracloacal and 4 pairs postcloacal), the presence of a particular papilliform medioventral, postcloacal ornamentation and the morphology of the eggs and tip of the female tail. In addition, Ophidascaris najae (Gedoelst, 1916), collected from the king cobra Ophiophagus hannah Cantor (Serpentes: Elapidae) in China, is also redescribed. The morphology of the cervical papillae, labial denticles and phasmids of the female is described for the first time.

  19. Biological effects of Naja haje crude venom on the hepatic and renal tissues of mice

    Amany A. Tohamy

    2014-07-01

    Full Text Available Snake venoms are known to cause different metabolic disorders, altering cellular and enzymatic activities in animals and releasing pharmacological substances. In this study, the lethality as well as biochemical and histopathological effect of Egyptian cobra (Naja haje; N. haje crude venom at a sublethal dose have been investigated on liver and kidney of male mice. Venom injected intramuscularly in mice with 1/2 LD50 (approximately 0.0115 μg/g body weight of mice and the animals were sacrificed 6 days post injection. Results indicated that the injection of crude venom of the N. haje induced a significant disturbance in liver and kidney functions. In addition, results revealed that N. haje venom has a potent oxidative activity by increasing the level of reactive oxygen species with concomitant significant increase in hydrogen peroxide, lipid peroxidation, carbonyl protein and nitric oxide levels in hepatic and renal tissues. This activity was extended to decrease non-enzymatic and enzymatic antioxidant defense components such as glutathione, superoxide dismutase and catalase. Additionally, the biochemical alternations induced in hepatic and renal tissues were associated with significant alternations in the histological architecture of liver and kidney of injected mice. From this study, we can conclude that such injury could be considered among the factors that lead to death caused by N. haje venom.

  20. Adjuvantes e herbicidas e a infectividade de Fusarium graminearum, agente potencial de biocontrole de Egeria densa e Egeria najas Adjuvants and herbicides and the infectivity of Fusarium graminearum, a potential biocontrol agent of Egeria densa and Egeria najas

    C.R. Borges Neto

    2004-03-01

    Full Text Available Foram estudados os efeitos da adição de adjuvantes e a associação com herbicidas na infectividade do fungo dentro do patossistema Fusarium graminearum x Egeria spp. Foram utilizadas plantas sadias de Egeria densa e E. najas inoculadas com uma suspensão de arroz moído colonizado por F. graminearum, na concentração de 0,7 g L-1. Os tubos de ensaio contendo as plantas imersas na referida suspensão foram mantidos em incubadora à temperatura de 25 ºC e fotoperíodo de 12 horas diárias de luz, por oito dias, durante os quais foram avaliados os sintomas nas plantas a cada dois dias e o crescimento destas através do incremento de matéria fresca ao final do experimento. O efeito de 14 adjuvantes e 6 herbicidas, adicionados à suspensão de inóculo, sobre a ação de F. graminearum em E. densa e E. najas foi avaliado. De modo geral, os adjuvantes melhoraram a eficiência do bioerbicida e a associação herbicida + fungo proporcionou maior severidade de doença e controle do crescimento das plantas.The effects of adding adjuvants and their association with herbicides on fungus infectivity were studied in the Fusarium graminearum x Egeria spp. pathosystem. Healthy Egeria densa and E. naja plants were inoculated with suspension of ground rice with F. graminearum, at a concentration of 0.7 g L-1. The assay tubes with the plants immersed in the suspension were kept in the incubator at the temperature of 25 ºC and photoperiod of 12 hours daily, with plant symptoms being evaluated every two hours and plant growth monitored based on fresh matter increase at the end of the experiment. The effect of 14 adjuvants and 6 herbicides added to the inoculum on the action of F. graminearum against E. densa and E. najas was evaluated. In general, the adjuvants improved bioherbicide efficiency and the herbicide + fungus association increased disease severity and plant growth control.

  1. Studies on Impact of Irradiation Treatment on Certain Pharmacological and Biochemical Responses of Naja nigricollis Snake Venom

    Abd El Hamid, F.Y.A.

    2015-01-01

    Snakebite is a serious medical problem worldwide, especially in the tropics. In Egypt, the Black-neck Spitting Cobra; Naja nigricollis is one of the most venomous snakes distributed in the south part of Egypt. The lethality as well as the immunological, biochemical and histological effects of Naja nigricollis venom at a sublethal dose has been investigated before and after exposure to gamma radiation (1.5 KGy and 3 KGy). The toxicity of irradiated venom decreased as compared to that of the native one. There was no change in the antigenic reactivity between both native and irradiated venom. The effect of ½ LD 50 of native or irradiated (1.5 KGy) was studied on the activities of heart enzymes: CPK, CK-MB, LDH and AST after (1, 2, 4, 24 hours) of envenomation. The present study showed that snake venom envenomation caused significant (p ≤ 0.05) elevation in serum CPK, CK-MB, LDH and AST levels. In contrast, the 1.5 KGy gamma-irradiated venom recorded no significant changes compared to that of normal rats. Histopathological study of heart confirmed these findings. The 1.5 KGy and 3 KGy gamma irradiation decrease the phospholipase activity of the venom. Anticoagulant activity was prominent when re calcification time was tested on human plasma using each venom (native, γ- irradiated venoms) as a test solution. Naja nigricollis venom detoxified by gamma irradiation (1.5 KGy or 3 KGy) was used as toxoid for active immunization of rabbits following a short schedule of immunization with complete Freund's adjuvant. Effective neutralization of venom toxin by immune sera of rabbits was observed.

  2. Pharmacokinetics of Naja sumatrana (equatorial spitting cobra venom and its major toxins in experimentally envenomed rabbits.

    Michelle Khai Khun Yap

    2014-06-01

    Full Text Available The optimization of snakebite management and the use of antivenom depend greatly on the knowledge of the venom's composition as well as its pharmacokinetics. To date, however, pharmacokinetic reports on cobra venoms and their toxins are still relatively limited. In the present study, we investigated the pharmacokinetics of Naja sumatrana (Equatorial spitting cobra venom and its major toxins (phospholipase A2, neurotoxin and cardiotoxin, following intravenous and intramuscular administration into rabbits.The serum antigen concentration-time profile of the N. sumatrana venom and its major toxins injected intravenously fitted a two-compartment model of pharmacokinetics. The systemic clearance (91.3 ml/h, terminal phase half-life (13.6 h and systemic bioavailability (41.9% of N. sumatrana venom injected intramuscularly were similar to those of N. sputatrix venom determined in an earlier study. The venom neurotoxin and cardiotoxin reached their peak concentrations within 30 min following intramuscular injection, relatively faster than the phospholipase A2 and whole venom (Tmax=2 h and 1 h, respectively. Rapid absorption of the neurotoxin and cardiotoxin from the injection site into systemic circulation indicates fast onsets of action of these principal toxins that are responsible for the early systemic manifestation of envenoming. The more prominent role of the neurotoxin in N. sumatrana systemic envenoming is further supported by its significantly higher intramuscular bioavailability (Fi.m.=81.5% compared to that of the phospholipase A2 (Fi.m.=68.6% or cardiotoxin (Fi.m.=45.6%. The incomplete absorption of the phospholipase A2 and cardiotoxin may infer the toxins' affinities for tissues at the injection site and their pathological roles in local tissue damages through synergistic interactions.Our results suggest that the venom neurotoxin is absorbed very rapidly and has the highest bioavailability following intramuscular injection, supporting its

  3. Detection of Naja atra Cardiotoxin Using Adenosine-Based Molecular Beacon.

    Shi, Yi-Jun; Chen, Ying-Jung; Hu, Wan-Ping; Chang, Long-Sen

    2017-01-07

    This study presents an adenosine (A)-based molecular beacon (MB) for selective detection of Naja atra cardiotoxin (CTX) that functions by utilizing the competitive binding between CTX and the poly(A) stem of MB to coralyne. The 5'- and 3'-end of MB were labeled with a reporter fluorophore and a non-fluorescent quencher, respectively. Coralyne induced formation of the stem-loop MB structure through A₂-coralyne-A₂ coordination, causing fluorescence signal turn-off due to fluorescence resonance energy transfer between the fluorophore and quencher. CTX3 could bind to coralyne. Moreover, CTX3 alone induced the folding of MB structure and quenching of MB fluorescence. Unlike that of snake venom α-neurotoxins, the fluorescence signal of coralyne-MB complexes produced a bell-shaped concentration-dependent curve in the presence of CTX3 and CTX isotoxins; a turn-on fluorescence signal was noted when CTX concentration was ≤80 nM, while a turn-off fluorescence signal was noted with a further increase in toxin concentrations. The fluorescence signal of coralyne-MB complexes yielded a bell-shaped curve in response to varying concentrations of N. atra crude venom but not those of Bungarus multicinctus and Protobothrops mucrosquamatus venoms. Moreover, N. nigricollis venom also functioned as N. atra venom to yield a bell-shaped concentration-dependent curve of MB fluorescence signal, again supporting that the hairpin-shaped MB could detect crude venoms containing CTXs. Taken together, our data validate that a platform composed of coralyne-induced stem-loop MB structure selectively detects CTXs.

  4. Proteomic characterization of venom of the medically important Southeast Asian Naja sumatrana (Equatorial spitting cobra).

    Yap, Michelle Khai Khun; Fung, Shin Yee; Tan, Kae Yi; Tan, Nget Hong

    2014-05-01

    The proteome of Naja sumatrana (Equatorial spitting cobra) venom was investigated by shotgun analysis and a combination of ion-exchange chromatography and reverse phase HPLC. Shotgun analysis revealed the presence of 39 proteins in the venom while the chromatographic approach identified 37 venom proteins. The results indicated that, like other Asiatic cobra venoms, N. sumatrana contains large number of three finger toxins and phospholipases A2, which together constitute 92.1% by weight of venom protein. However, only eight of the toxins can be considered as major venom toxins. These include two phospholipases A2, three neurotoxins (two long neurotoxins and a short neurotoxin) and three cardiotoxins. The eight major toxins have relative abundance of 1.6-27.2% venom proteins and together account for 89.8% (by weight) of total venom protein. Other venom proteins identified include Zn-metalloproteinase-disintegrin, Thaicobrin, CRISP, natriuretic peptide, complement depleting factors, cobra venom factors, venom nerve growth factor and cobra serum albumin. The proteome of N. sumatrana venom is similar to proteome of other Asiatic cobra venoms but differs from that of African spitting cobra venom. Our results confirm that the main toxic action of N. sumatrana venom is neurotoxic but the large amount of cardiotoxins and phospholipases A2 are likely to contribute significantly to the overall pathophysiological action of the venom. The differences in toxin distribution between N. sumatrana venom and African spitting cobra venoms suggest possible differences in the pathophysiological actions of N. sumatrana venom and the African spitting cobra venoms, and explain why antivenom raised against Asiatic cobra venom is not effective against African spitting cobra venoms. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Antisnake Venom Activity of Hibiscus aethiopicus L. against Echis ocellatus and Naja n. nigricollis

    S. S. Hasson

    2010-01-01

    Full Text Available The objective of the study is to investigate whether the Hibiscus aethiopicus L. plant has neutralization activity against venoms of two clinically important snakes. The H. aethiopicus was dried and extracted with water. Different assays were performed to evaluate the plant's acute toxicity and its anti-snake venom activities. The results showed that H. aethiopicus extract alone had no effect on the viability of C2C12 muscle cells, but significantly (P<.05 protected muscle cells against the toxic effects of E. ocellatus venom at 55, 150, and 300 μg/mL. The maximum protective effect of the extract was exhibited at 75 μg/mL. The extract significantly (P<.001 inhibited the cytotoxic effects of E. ocellatus venom at 300 μg/mL. All rabbits (n=10 and guinea pigs (n=10 were alive after the two weeks of given the lethal dosage 16 g/Kg of the H. aethiopicus extract herbal solution. No abnormal behaviour was observed of both groups of animals. All guinea pigs (n=3 treated with venoms alone (5 mg/kg died. However, all guinea pigs (n=21 treated with venom (5 mg/kg and the extract (400 to 1000 mg/kg survived. Guinea pigs (n=3 treated with Naja n. nigricollis venom alone (2.5 mg/kg and guinea pigs (n=21 venom with the extract (400 to 1000 mg/kg died. The H. aethiopicus completely (100% blocked the haemorrhagic activity of E. ocellatus in the egg embryo at 3.3 mg/mL of extract. These findings suggest that H. aethiopicus may contain an endogenous inhibitor of venom-induced haemorrhage.

  6. Anti snake Venom Activity of Hibiscus aethiopicus L. against Echis ocellatus and Naja n. nigricollis

    Hasson, S.S.; Al-Jabri, A.A.; Al-Balushi, M.S.; Hasson, S.S.; Sallam, T.A.; Mothana, R.A.A.

    2010-01-01

    The objective of the study is to investigate whether the Hibiscus aethiopicus L. plant has neutralization activity against venoms of two clinically important snakes. The H. aethiopicus was dried and extracted with water. Different assays were performed to evaluate the plant's acute toxicity and its anti-snake venom activities. The results showed that H. aethiopicus extract alone had no effect on the viability of C 2 C 12 muscle cells, but significantly (P<.05) protected muscle cells against the toxic effects of E. ocellatus venom at 55, 150, and 300 μg/ mL. The maximum protective effect of the extract was exhibited at 75μg/mL. The extract significantly (P<.001) inhibited the cytotoxic effects of E. ocellatus venom at 300?μg/mL. All rabbits (n=10) and guinea pigs (n=10) were alive after the two weeks of given the lethal dosage 16g/Kg of the H. aethiopicus extract herbal solution. No abnormal behaviour was observed of both groups of animals. All guinea pigs (n=3) treated with venoms alone (5 mg/kg) died. However, all guinea pigs (n=21) treated with venom (5 mg/kg) and the extract (400 to 1000 mg/kg) survived. Guinea pigs (n=3) treated with Naja n. nigricollis venom alone (2.5 mg/kg) and guinea pigs (n=21) venom with the extract (400 to 1000 mg/kg) died. The H. aethiopicus completely (100%) blocked the haemorrhagic activity of E. ocellatus in the egg embryo at 3.3mg/ mL of extract. These findings suggest that H. aethiopicus may contain an endogenous inhibitor of venom-induced haemorrhage.

  7. Structure of N-Terminal Sequence Asp-Ala-Glu-Phe-Arg-His-Asp-Ser of Aβ-Peptide with Phospholipase A2 from Venom of Andaman Cobra Sub-Species Naja naja sagittifera at 2.0 Å Resolution

    Zeenat Mirza

    2014-03-01

    Full Text Available Alzheimer’s disease (AD is one of the most significant social and health burdens of the present century. Plaques formed by extracellular deposits of amyloid β (Aβ are the prime player of AD’s neuropathology. Studies have implicated the varied role of phospholipase A2 (PLA2 in brain where it contributes to neuronal growth and inflammatory response. Overall contour and chemical nature of the substrate-binding channel in the low molecular weight PLA2s are similar. This study involves the reductionist fragment-based approach to understand the structure adopted by N-terminal fragment of Alzheimer’s Aβ peptide in its complex with PLA2. In the current communication, we report the structure determined by X-ray crystallography of N-terminal sequence Asp-Ala-Glu-Phe-Arg-His-Asp-Ser (DAEFRHDS of Aβ-peptide with a Group I PLA2 purified from venom of Andaman Cobra sub-species Naja naja sagittifera at 2.0 Å resolution (Protein Data Bank (PDB Code: 3JQ5. This is probably the first attempt to structurally establish interaction between amyloid-β peptide fragment and hydrophobic substrate binding site of PLA2 involving H bond and van der Waals interactions. We speculate that higher affinity between Aβ and PLA2 has the therapeutic potential of decreasing the Aβ–Aβ interaction, thereby reducing the amyloid aggregation and plaque formation in AD.

  8. Hierarchical structure and mechanical properties of snake (Naja atra) and turtle (Ocadia sinensis) eggshells.

    Chang, Yin; Chen, Po-Yu

    2016-02-01

    After hundreds of million years of evolution, natural armors have evolved in various organisms, and has manifested in diverse forms such as eggshells, abalone shells, alligator osteoderms, turtle shells, and fish scales. Eggshells serve as multifunctional shields for successful embryogenesis, such as protection, moisture control and thermal regulation. Unlike calcareous avian eggshells which are brittle and hard, reptilians have leathery eggshells that are tough and flexible. Reptilian eggshells can withstand collision damages when laid in holes and dropped onto each other, and reduce abrasion caused by buried sand. In this study, we investigate structure and mechanical properties of eggshells of Taiwan cobra snake (Naja atra) and Chinese striped-neck turtle (Ocadia sinensis). From Acid Fuchsin Orange G (AFOG) staining and ATR-FTIR examination, we found that both eggshells are mainly composed of keratin. The mechanical properties of demineralized snake and turtle eggshells were evaluated by tensile and fracture tests and show distinctly difference. Turtle eggshells are relatively stiff and rigid, while snake eggshells behave as elastomers, which are highly extensible and reversible. The exceptional deformability (110-230% tensile strain) and toughness of snake eggshells are contributed by the wavy and random arrangement of keratin fibers as well as collagen layers. Multi-scale toughening mechanisms of snake eggshells were observed and elucidated, including crack deflection and twisting, fibers reorientation, sliding and bridging, inter-laminar shear effect, as well as the α-β phase transition of keratin. Inspirations from the structural and mechanical designs of reptilian eggshells may lead to the synthesis of tough, extensible, lightweight composites which could be further applied in the flexible devices, packaging and bio-medical fields. Amniotic eggshells serve as multifunctional shields for successful embryogenesis. The avian eggshells have been extensively

  9. The protective effects of Mucuna pruriens seed extract against histopathological changes induced by Malayan cobra (Naja sputatrix) venom in rats.

    Fung, S Y; Tan, N H; Liew, S H; Sim, S M; Aguiyi, J C

    2009-04-01

    Seed of Mucuna pruriens (Velvet beans) has been prescribed by traditional medicine practitioners in Nigeria as a prophylactic oral antisnake remedy. In the present studies, we investigated the protective effects of M. pruriens seed extract (MPE) against histopathological changes induced by intravenous injection of Naja sputatrix (Malayan cobra) venom in rats pretreated with the seed extract. Examination by light microscope revealed that the venom induced histopathological changes in heart and blood vessels in liver, but no effect on brain, lung, kidney and spleen. The induced changes were prevented by pretreatment of the rats with MPE. Our results suggest that MPE pretreatment protects rat heart and liver blood vessels against cobra venom-induced damages.

  10. In situ experiments to determine the uptake of copper by the aquatic macrophyte Najas tenuifolia R.Br

    Hart, B.T.; Jones, M.J.; Breen, P.

    1984-01-01

    In situ experiments, in which ionic copper was added to an enclosed area of the aquatic macrophyte Najas tenuifolia R.Br., showed that this plant can rapidly (in around six hours) take up considerable amounts of the added copper. Epiphytes (and their associated microfauna) present on this macrophyte took up the added copper even more rapidly, but also seemed to release the copper equally fast. At the end of the three day experiment 30% to 60% of the added copper was associated with the macrophytes and 15% to 20% was still in the water column. The remainder of the copper was associated with the 'epiphyte component', the sediments and probably also the walls of the plastic enclosure

  11. Exploring the venom of the forest cobra snake: Toxicovenomics and antivenom profiling of Naja melanoleuca.

    Lauridsen, Line P; Laustsen, Andreas H; Lomonte, Bruno; Gutiérrez, José María

    2017-01-06

    A toxicovenomic analysis of the venom of the forest cobra, N. melanoleuca, was performed, revealing the presence of a total of 52 proteins by proteomics analysis. The most abundant proteins belong to the three-finger toxins (3FTx) (57.1wt%), which includes post-synaptically acting α-neurotoxins. Phospholipases A 2 (PLA 2 ) were the second most abundant group of proteins (12.9wt%), followed by metalloproteinases (SVMPs) (9.7wt%), cysteine-rich secretory proteins (CRISPs) (7.6wt%), and Kunitz-type serine proteinase inhibitors (3.8wt%). A number of additional protein families comprised each <3wt% of venom proteins. A toxicity screening of the fractions, using the mouse lethality test, identified toxicity in RP-HPLC peaks 3, 4, 5 and 8, all of them containing α-neurotoxins of the 3FTx family, whereas the rest of the fractions did not show toxicity at a dose of 0.53mg/kg. Three polyspecific antivenoms manufactured in South Africa and India were tested for their immunoreactivity against crude venom and fractions of N. melanoleuca. Overall, antivenoms immunorecognized all fractions in the venom, the South African antivenom showing a higher titer against the neurotoxin-containing fractions. This toxicovenomic study identified the 3FTx group of α-neurotoxins in the venom of N. melanoleuca as the relevant targets to be neutralized. A toxicovenomic analysis of the venom of the forest cobra, also known as black cobra, Naja melanoleuca, was performed. Envenomings by this elapid species are characterized by a progressive descending paralysis which starts with palpebral ptosis and, in severe cases, ends up with respiratory arrest and death. A total of 52 different proteins were identified in this venom. The most abundant protein family was the three-finger toxin (3FTx) family, which comprises almost 57.1wt% of the venom, followed by phospholipases A 2 (PLA 2 ) (12.9wt%). In addition, several other protein families were identified in a much lower percentage in the venom. A

  12. Diferenciação entre Egeria densa e Egeria najas pelos caracteres anatômicos foliares Differentiation between Egeria densa and Egeria najas by leaf anatomic characters

    R.A. Rodella

    2006-06-01

    Full Text Available Dentre as plantas daninhas aquáticas imersas de maior importância nos reservatórios de usinas hidrelétricas e em represas de pequeno porte no Brasil, destacam-se as espécies Egeria densa e Egeria najas, cuja identificação pode ser difícil na fase vegetativa. O objetivo deste trabalho foi diferenciar cinco acessos de E. densa e três de E. najas, coletados nos reservatórios de Jupiá, Salto Grande, Três Irmãos, Promissão, Nova Avanhandava e Ibitinga, do complexo da Companhia Energética de São Paulo (CESP do Estado de São Paulo, quanto às características anatômicas descritivas e quantitativas do limbo foliar, procurando-se obter melhor entendimento sobre as relações dessas estruturas anatômicas com a penetração e translocação de herbicidas, além de auxiliar na identificação de acessos suscetíveis e resistentes a determinado produto químico. Amostras do terço médio do limbo foram fixadas em FAA 50, cortadas transversalmente em micrótomo rotatório com 8 mm de espessura e coradas com azul-de-toluidina. Foi analisada a estrutura foliar e foram quantificados os caracteres anatômicos da nervura central (% epiderme das faces adaxial e abaxial, % feixe vascular e % parênquima e da região situada entre a nervura e o bordo do limbo (% epiderme das faces adaxial e abaxial e espessura da folha. Os dados das variáveis quantitativas foram submetidos aos testes estatísticos multivariados de Análise de Agrupamento e Análise de Componentes Principais. Houve formação de três grupos principais: o primeiro foi constituído pelos três acessos de E. najas; o segundo, por quatro acessos de E. densa; e o terceiro, por apenas um acesso de E. densa. O caráter que mais contribuiu para a diferenciação entre os acessos foi a % feixe vascular da nervura central, seguido da % epiderme da face abaxial da nervura central e % epiderme das faces adaxial e abaxial da região entre a nervura e o bordo foliar. Concluiu-se que a utiliza

  13. Snake venomics of monocled cobra (Naja kaouthia) and investigation of human IgG response against venom toxins

    Laustsen, Andreas Hougaard; Gutiérrez, José María; Lohse, Brian

    2015-01-01

    /cardiotoxins. IgGs isolated from a person who had repeatedly self-immunized with a variety of snake venoms were immunoprofiled by ELISA against all venom fractions. Stronger responses against larger toxins, but lower against the most critical α-neurotoxins were obtained. As expected, no neutralization potential...

  14. IN VITRO INHIBITORY EFFECTS OF GAMMA RADIATION ON NAJA NIGRICOLLIS SNAKE VENOM INDUCED HEP-2 CELL INJURY

    ABOUELELLA, A.M.

    2008-01-01

    Naja nigricollis venom was irradiated with four different doses of gamma rays; 1, 5, 20 and 50 kGy, from 6 0C o source. The ability of gamma rays to attenuate the cytotoxic effects of N. nigricollis venom was investigated on HEp-2 cell line. The cell necrosis was measured by lactate dehydrogenase (LDH) and malondialdehyde (MDA) while cell apoptosis was measured by DNA fragmentation, nitric oxide (NO) synthesis, mitochondrial cytochrome-C release and cleavage of both caspase-3 and PARP-1. The results showed that gamma irradiation reduced significantly the necrotic effects of N. nigricollis venom in almost all irradiation doses of venom, especially at 1 and 50 kGy. DNA fragmentation showed decreased apoptotic effects after exposing of snake venom to gamma radiation. Venom exposed to 1 kGy showed the highest decrease in the NO (47.5±2.4 M) while the 50kGy showed the highest decrease in the MDA release (11.75 ±0.6 nmol/ml). The mitochondrial cytochrome-C was released after treatment with all radiation doses while caspase-3 was cleaved in only the cells incubated with radiated venom of 5 and 20 kGy which were consistent with the results of PARP-1 cleavage at the same radiation doses

  15. Prophylactic effect of Mucuna pruriens Linn (velvet bean) seed extract against experimental Naja sputatrix envenomation: gene expression studies.

    Fung, Shin Yee; Sim, Si Mui; Kandiah; Jeyaseelan; Armugam, Arunmozhiarasi; Aguiyi, John Chinyere; Tan, Nget Hong

    2014-09-01

    Mucuna pruriens is widely used in traditional medicine for treatments of various diseases. In certain region of Nigeria, the seed is used as oral prophylactics for snakebite. Rats pretreated with the aqueous extract from M. pruriens seed (MPE) were protected against the lethal effects of Naja sputatrix (Javan spitting cobra) venom [Tan et al., J Ethnopharmacol, 123 (2009) 356]. The pretreatment also protected against venom-induced histopathological changes in rat heart. To contribute to the understanding of the mechanism of cardio-protective action, the present study examined the effects of MPE-pretreatment on gene expression profile of rat heart as well as effect of MPE-pretreatment on N. sputatrix venom-induced gene expression alterations in rat heart. The gene expression profiles were examined by microarray analysis and verified by real time PCR. The results showed that pretreatment with MPE caused 50 genes in the rat heart substantially up-regulated of which 19 were related to immune responses, 7 were related to energy production and metabolism. The up-regulation of genes related to energy metabolism probably plays a role in maintaining the viability of the heart. Four other genes that were up-regulated (alpha synuclein, natriuretic peptide precursor, calsequestrin and triadin) were involved in the maintenance of homeostasis of the heart or maintaining its viability, thereby contributing to the direct protective action. The results demonstrated that protective effect of MPE pretreatment against snake venom poisoning may involve a direct action on the heart.

  16. The plastid genome of Najas flexilis: adaptation to submersed environments is accompanied by the complete loss of the NDH complex in an aquatic angiosperm.

    Elena L Peredo

    Full Text Available The re-colonization of aquatic habitats by angiosperms has presented a difficult challenge to plants whose long evolutionary history primarily reflects adaptations to terrestrial conditions. Many aquatics must complete vital stages of their life cycle on the water surface by means of floating or emergent leaves and flowers. Only a few species, mainly within the order Alismatales, are able to complete all aspects of their life cycle including pollination, entirely underwater. Water-pollinated Alismatales include seagrasses and water nymphs (Najas, the latter being the only freshwater genus in the family Hydrocharitaceae with subsurface water-pollination. We have determined the complete nucleotide sequence of the plastid genome of Najas flexilis. The plastid genome of N. flexilis is a circular AT-rich DNA molecule of 156 kb, which displays a quadripartite structure with two inverted repeats (IR separating the large single copy (LSC from the small single copy (SSC regions. In N. flexilis, as in other Alismatales, the rps19 and trnH genes are localized in the LSC region instead of within the IR regions as in other monocots. However, the N. flexilis plastid genome presents some anomalous modifications. The size of the SSC region is only one third of that reported for closely related species. The number of genes in the plastid is considerably less. Both features are due to loss of the eleven ndh genes in the Najas flexilis plastid. In angiosperms, the absence of ndh genes has been related mainly to the loss of photosynthetic function in parasitic plants. The ndh genes encode the NAD(PH dehydrogenase complex, believed essential in terrestrial environments, where it increases photosynthetic efficiency in variable light intensities. The modified structure of the N. flexilis plastid genome suggests that adaptation to submersed environments, where light is scarce, has involved the loss of the NDH complex in at least some photosynthetic angiosperms.

  17. Effect of Mucuna pruriens Seed Extract Pretreatment on the Responses of Spontaneously Beating Rat Atria and Aortic Ring to Naja sputatrix (Javan Spitting Cobra) Venom

    Fung, Shin Yee; Tan, Nget Hong; Sim, Si Mui; Aguiyi, John C.

    2012-01-01

    Mucuna pruriens Linn. (velvet bean) has been used by native Nigerians as a prophylactic for snakebite. Rats pretreated with M. pruriens seed extract (MPE) have been shown to protect against the lethal and cardiovascular depressant effects of Naja sputatrix (Javan spitting cobra) venoms, and the protective effect involved immunological neutralization of the venom toxins. To investigate further the mechanism of the protective effect of MPE pretreatment against cobra venom toxicity, the actions of Naja sputatrix venom on spontaneously beating rat atria and aortic rings isolated from both MPE pretreated and untreated rats were studied. Our results showed that the MPE pretreatment conferred protection against cobra venom-induced depression of atrial contractility and atrial rate in the isolated atrial preparations, but it had no effect on the venom-induced contractile response of aortic ring preparation. These observations suggested that the protective effect of MPE pretreatment against cobra venom toxicity involves a direct protective action of MPE on the heart function, in addition to the known immunological neutralization mechanism, and that the protective effect does not involve action on blood vessel contraction. The results also suggest that M. pruriens seed may contain novel cardioprotective agent with potential therapeutic value. PMID:21785646

  18. Effect of Mucuna pruriens Seed Extract Pretreatment on the Responses of Spontaneously Beating Rat Atria and Aortic Ring to Naja sputatrix (Javan Spitting Cobra Venom

    Shin Yee Fung

    2012-01-01

    Full Text Available Mucuna pruriens Linn. (velvet bean has been used by native Nigerians as a prophylactic for snakebite. Rats pretreated with M. pruriens seed extract (MPE have been shown to protect against the lethal and cardiovascular depressant effects of Naja sputatrix (Javan spitting cobra venoms, and the protective effect involved immunological neutralization of the venom toxins. To investigate further the mechanism of the protective effect of MPE pretreatment against cobra venom toxicity, the actions of Naja sputatrix venom on spontaneously beating rat atria and aortic rings isolated from both MPE pretreated and untreated rats were studied. Our results showed that the MPE pretreatment conferred protection against cobra venom-induced depression of atrial contractility and atrial rate in the isolated atrial preparations, but it had no effect on the venom-induced contractile response of aortic ring preparation. These observations suggested that the protective effect of MPE pretreatment against cobra venom toxicity involves a direct protective action of MPE on the heart function, in addition to the known immunological neutralization mechanism, and that the protective effect does not involve action on blood vessel contraction. The results also suggest that M. pruriens seed may contain novel cardioprotective agent with potential therapeutic value.

  19. Naja nigricollis CMS-9 enhances the mitochondria-mediated death pathway in adaphostin-treated human leukaemia U937 cells.

    Chen, Ying-Jung; Wang, Jeh-Jeng; Chang, Long-Sen

    2011-11-01

    1. The aim of the present study was to explore the effect of the Naja nigricollis phospholipase A(2) CMS-9 on adaphostin-induced death of human leukaemia U937 cells. 2. Leukaemia U937 cells (Bcr/Abl-negative cells) were treated with adaphostin (0-10 μmol/L) and CMS-9 (0-1 μmol/L). The effects of CMS-9, adaphostin and their combination on cell viability, the generation reactive oxygen species (ROS), [Ca(2+) ](i) , p38 mitogen-activated protein kinase (MAPK) activation, Akt and extracellular signal-regulated kinase (ERK) inactivation, mitochondrial membrane potential (ΔΨ(m) ) and Bcl-2 family proteins were analysed. 3. Both adaphostin and CMS-9 induced U937 cell apoptosis, characterized by dissipation of ΔΨ(m) and ROS generation. Combined treatment further increased ΔΨ(m) loss and reduced the viability of adaphostin-treated cells. Unlike in CMS-9-treated cells, in adaphostin-treated cells ROS-induced increases in [Ca(2+) ](i) were observed. CMS-9-induced ROS generation resulted in p38 MAPK activation, whereas adaphostin treatment elicited ROS/Ca(2+) -mediated inactivation of Akt and ERK. Moreover, Akt was found to be involved in ERK phosphorylation. Suppression of p38 MAPK activation blocked CMS-9-induced ΔΨ(m) loss and Bcl-xL downregulation. Overexpression of constitutively active Akt and mitogen-activated protein kinase kinase (MEK) 1 rescued adaphostin-induced ΔΨ(m) loss and Bcl-2 downregulation. Similarly, CMS-9 augmented adaphostin toxicity in human leukaemia K562 cells via increased mitochondrial alterations. 4. The results suggest that two distinct pathways mediate adaphostin- and CMS-9-induced mitochondrial damage (i.e. the ROS-Ca(2+) -Akt-ERK and ROS-p38 MAPK pathways, respectively). These distinct pathway explain the augmentation by CMS-9 of ΔΨ(m) loss and apoptosis in adaphostin-treated U937 cells. © 2011 The Authors. Clinical and Experimental Pharmacology and Physiology © 2011 Blackwell Publishing Asia Pty Ltd.

  20. Efeito do período de exposição a concentrações de diquat no controle de plantas de Egeria densa, Egeria najas e Ceratophyllum demersum Effect of the period of exposure to diquat concentrations on the control of Egeria densa, Egeria najas and Ceratophyllum demersum

    D. Martins

    2008-01-01

    Full Text Available O período de permanência do herbicida na água pode ser influenciado pelo fluxo da água nos reservatórios e pela adsorção a partículas de argilas em suspensão, bem como pela degradação luminosa e por microrganismos. Objetivou-se com este trabalho avaliar diferentes períodos de exposição a concentrações do herbicida diquat no controle de Egeria densa, Egeria najas e Ceratophyllum demersum. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições, em esquema fatorial 6 x 5, mais uma testemunha. Foram testados seis períodos de exposição das plantas (30, 60, 120, 240, 480 e 960 minutos a cinco concentrações do herbicida diquat (0,075; 0,15; 0,3; 0,6; e 1,2 ppm produto comercial Reward 240 g L ¹. As avaliações de controle das plantas daninhas imersas foram visuais e, no final do experimento, foi avaliada a massa seca das plantas, para determinar a porcentagem de redução da biomassa. Observou-se que apenas 30 minutos de exposição das espécies imersas E. densa e C. demersum à concentração de 0,075 ppm foi suficiente para proporcionar redução da massa seca em ambas as espécies. Para controle de E. najas aos 7 DAA houve necessidade de um período maior que 120 minutos de exposição, considerando a mesma concentração do herbicida. Esses resultados evidenciam o potencial de uso do diquat no controle de plantas daninhas aquáticas imersas em locais que apresentam rápida renovação de água.The period of herbicide permanence in water can be influenced by the water flow in the reservoirs and the adsorption of clay particles in suspension, as well as by luminous degradation and microorganisms. Thus, the objective of this work was to evaluate the effect of different exposure periods to diquat concentrations on the control of Egeria densa, Egeria najas and Ceratophyllum demersum. The experimental design used was completely randomized, with four replicates, in a factorial scheme 6 x 5

  1. Involvement of p38 MAPK- and JNK-modulated expression of Bcl-2 and Bax in Naja nigricollis CMS-9-induced apoptosis of human leukemia K562 cells.

    Chen, Ying-Jung; Liu, Wen-Hsin; Kao, Pei-Hsiu; Wang, Jeh-Jeng; Chang, Long-Sen

    2010-06-15

    CMS-9, a phospholipase A(2) (PLA(2)) isolated from Naja nigricollis venom, induced apoptosis of human leukemia K562 cells, characterized by mitochondrial depolarization, modulation of Bcl-2 family members, cytochrome c release and activation of caspases 9 and 3. Moreover, an increase in intracellular Ca2+ concentration and the production of reactive oxygen species (ROS) was noted. Pretreatment with BAPTA-AM (Ca2+ chelator) and N-acetylcysteine (NAC, ROS scavenger) proved that Ca2+ was an upstream event in inducing ROS generation. Upon exposure to CMS-9, activation of p38 MAPK and JNK was observed in K562 cells. BAPTA-AM or NAC abrogated CMS-9-elicited p38 MAPK and JNK activation, and rescued viability of CMS-9-treated K562 cells. SB202190 (p38 MAPK inhibitor) and SP600125 (JNK inhibitor) suppressed CMS-9-induced dissipation of mitochondrial membrane potential, Bcl-2 down-regulation, Bax up-regulation and increased mitochondrial translocation of Bax. Inactivation of PLA(2) activity reduced drastically the cytotoxicity of CMS-9, and a combination of lysophosphatidylcholine and stearic acid mimicked the cytotoxic effects of CMS-9. Taken together, our data suggest that CMS-9-induced apoptosis of K562 cells is catalytic activity-dependent and is mediated through mitochondria-mediated death pathway triggered by Ca2+/ROS-evoked p38 MAPK and JNK activation. 2010 Elsevier Ltd. All rights reserved.

  2. Phospholipase A2 activity-dependent and -independent fusogenic activity of Naja nigricollis CMS-9 on zwitterionic and anionic phospholipid vesicles.

    Chiou, Yi-Ling; Chen, Ying-Jung; Lin, Shinne-Ren; Chang, Long-Sen

    2011-11-01

    CMS-9, a phospholipase A(2) (PLA(2)) from Naja nigricollis venom, induced the death of human breast cancer MCF-7 cells accompanied with the formation of cell clumps without clear boundaries between cells. Annexin V-FITC staining indicated that abundant phosphatidylserine appeared on the outer membrane of MCF-7 cell clumps, implying the possibility that CMS-9 may promote membrane fusion via anionic phospholipids. To validate this proposition, fusogenic activity of CMS-9 on vesicles composed of zwitterionic phospholipid alone or a combination of zwitterionic and anionic phospholipids was examined. Although CMS-9-induced fusion of zwitterionic phospholipid vesicles depended on PLA(2) activity, CMS-9-induced fusion of vesicles containing anionic phospholipids could occur without the involvement of PLA(2) activity. Membrane-damaging activity of CMS-9 was associated with its fusogenicity. Moreover, CMS-9 induced differently membrane leakage and membrane fusion of vesicles with different compositions. Membrane fluidity and binding capability with phospholipid vesicles were not related to the fusogenicity of CMS-9. However, membrane-bound conformation and mode of CMS-9 depended on phospholipid compositions. Collectively, our data suggest that PLA(2) activity-dependent and -independent fusogenicity of CMS-9 are closely related to its membrane-bound modes and targeted membrane compositions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Structural Insight into Specificity of Interactions between Nonconventional Three-finger Weak Toxin from Naja kaouthia (WTX) and Muscarinic Acetylcholine Receptors

    Lyukmanova, E. N.; Shenkarev, Z. O.; Shulepko, M. A.; Paramonov, A. S.; Chugunov, A. O.; Janíčková, Helena; Dolejší, Eva; Doležal, Vladimír; Utkin, Y.N.; Tsetlin, V.I.; Arseniev, A. S.; Efremov, R. G.; Dolgikh, D. A.; Kirpichnikov, M. P.

    2015-01-01

    Roč. 290, č. 39 (2015), s. 23616-23630 ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA14-05696S Institutional support: RVO:67985823 Keywords : computer modeling * G protein-coupled receptor (GPCR) * site-directed mutagenesis Subject RIV: ED - Physiology Impact factor: 4.258, year: 2015

  4. Eficácia do diquat no controle de Hydrilla verticillata, Egeria densa e Egeria najas e toxicidade aguda para o Guaru (Phallocerus caudimaculatus, em condições de laboratório Efficacy of diquat in the control of Hydrylla verticillata, Egeria densa and Egeria najas and its acute toxicity to Phallocerus caudimaculatus, under laboratory conditions

    M.N.P. Henares

    2011-06-01

    Full Text Available No Brasil, as macrófitas aquáticas submersas, Egeria densa e Egeria najas, têm causado prejuízos aos usos múltiplos da água. Hydrilla verticillata foi recentemente introduzida, mas tem histórico como planta problemática nos EUA, no México e na Austrália. O objetivo deste trabalho foi avaliar as suscetibilidades relativas dessas três macrófitas aquáticas ao diquat e os riscos da utilização desse herbicida para o guaru (Phallocerus caudimaculatus. Para isso, foram instalados ensaios em condições de laboratório, a fim de avaliar a suscetibilidade relativa das três macrófitas por meio da manutenção de ponteiros dessas plantas em soluções contendo 0,0; 0,2; 0,4; 0,8; e 1,6 mg L-1 de diquat (Reward® por 14 dias. A avaliação foi realizada pela variação do acúmulo de matéria fresca e do comprimento dos ponteiros no período de exposição ao herbicida. H. verticillata mostrou maior sensibilidade ao diquat em comparação com as duas macrófitas do gênero Egeria, mesmo em baixas concentrações do herbicida. Nas maiores concentrações, E. densa mostrou maior sensibilidade que E. najas. O risco da aplicação do diquat para P. caudimaculatus foi estimado pela toxicidade aguda. Alevinos de P. caudimaculatus de 0,4 ± 0,2 mg foram expostos a soluções de 0,0; 1,0; 5,0; 10,0; 15,0; 20,0; 25,0; e 30,0 mg L-1 de diquat. A concentração letal de 50% (CL(I (50;96h do diquat estimada para P. caudimaculatus foi de 7,17 mg L-1. Para P. caudimaculatus, a toxicidade aguda foi superior à concentração recomendada para o controle de macrófitas aquáticas submersas, indicando risco muito baixo para esse peixe.In Brazil, the submerged plants Egeria densa and Egeria najas have caused damage to multiple uses of water. Hydrilla verticillata has been recently introduced, but it has a history as a problem plant in the U.S., Mexico and Australia. The objectives of this work were to assess the relative susceptibilities of these three

  5. Cardiotoxin of the Indian cobra (Naja naja) is a pyrophosphatase

    Administrator

    and sugar phosphates at much lower rates. ... known to contain many other enzymes (Jimenez Porras, 1970). .... and the corresponding Vmax was only a third. ... far as heat stability is concerned, Fraction X shares this property with the pyro-.

  6. GC-MS and NMR analysis of the bioactive compounds from the crude extracts of Waltheria indica and the histopathological changes induced in albino rats challenged with Naja nigricollis venom

    Philip Ilani

    2016-05-01

    Full Text Available Objective: To develop a characteristic fingerprint of the different chemical compounds of plant by gas chromatography-mass spectrometer (GC-MS and nuclear magnetic resonance (NMR analysis and assess the effect of the crude extract on histological changes induced in Naja nigricollis (N. nigricollis envenomed albino rats. Methods: The coarsely powdered Waltheria indica (W. indica whole plant material was extracted using 70% methanol. GC-MS analysis was carried out using a Shimadzu GC-MS QP 2010 plus system of gas chromatography interfaced to a mass spectrometer. The identification of components was based on National Institute of Standard and Technology-08 and Willey-8 libraries. Hydrogen-NMR spectra of the extracts was performed using Bruker Biospin Avance 400-MHz NMR spectrophotometer with a 5 mm broad inverse probe head, equipped with shielded z-gradient accessories and C-13 NMR hetero-nuclear single quantum correction was carried out using the Brucker’s standard pulse library. The efficacy of the crude extract of W. indica whole plant was tested and the lesions induced in the liver, brain and kidney of albino rats challenged with N. nigricollis were analyzed by light microscopy. Results: The identification of the bioactive compounds from W. indica by GC-MS analysis revealed 41 peaks. A total of 38 compounds were identified with majority having important pharmacological activities that included anti-microbial, anti-cancer, anti-oxidant antiinflammatory, anti-allergenic, anti-ageing, anti-arthritic, larvicidal, anti-convulsant and herbicidal activities. C-13 and hydrogen-NMR analysis of W. indica elucidated key bioactive compounds in the whole plant that were consistent with the classes of bioactive compounds detected by GC-MS analysis. The efficacy of the crude extract of W. indica whole plant in ameliorating histopathological lesions induced in the liver, brain and kidney of albino rats challenged with N. nigricollis venom revealed the

  7. GC-MS and NMR analysis of the bioactive compounds from the crude extracts ofWaltheria indica and the histopathological changes induced in albino rats challenged withNaja nigricollis venom

    Philip Ilani; Nicholas Ajodo; Folashade Adewusi; Samirat Yakubu; Victor Yakubu Cosmos; Ache Eunice; Atonila Kayode Ezekiel; Oshiedu Sarah; Emmanuel Amlabu

    2016-01-01

    Objective:To develop a characteristic fingerprint of the different chemical compounds of plant by gas chromatography-mass spectrometer (GC-MS) and nuclear magnetic resonance (NMR) analysis and assess the effect of the crude extract on histological changes induced inNaja nigricollis(N. nigricollis)envenomed albino rats. Methods: The coarsely powderedWaltheria indica (W. indica) whole plant material was extracted using 70% methanol.GC-MS analysis was carried out using a ShimadzuGC-MS QP 2010 plus system of gas chromatography interfaced to a mass spectrometer. The identification of components was based on National Institute of Standard and Technology-08 and Willey-8 libraries. Hydrogen-NMR spectra of the extracts was performed using Bruker Biospin Avance 400-MHzNMR spectrophotometer with a 5 mm broad inverse probe head, equipped with shielded z-gradient accessories andC-13 NMR hetero-nuclear single quantum correction was carried out using the Brucker’s standard pulse library. The efficacy of the crude extract ofW. indica whole plant was tested and the lesions induced in the liver, brain and kidney of albino rats challenged withN. nigricollis were analyzed by light microscopy. Results:The identification of the bioactive compounds fromW. indica byGC-MS analysis revealed 41 peaks. A total of 38 compounds were identified with majority having important pharmacological activities that included anti-microbial, anti-cancer, anti-oxidant anti-inflammatory, anti-allergenic, anti-ageing, anti-arthritic, larvicidal, anti-convulsant and herbicidal activities.C-13 and hydrogen-NMR analysis ofW. indica elucidated key bioactive compounds in the whole plant that were consistent with the classes of bioactive compounds detected byGC-MS analysis. The efficacy of the crude extract ofW. indica whole plant in ameliorating histopathological lesions induced in the liver, brain and kidney of albino rats challenged withN. nigricollis venom revealed the abrogation of tissue degeneration when

  8. Preparation of cobra (Naja naja) venom toxoid using gamma-radiations. Part I

    Gaitonde, B.B.; Kankonkar, S.R.

    1975-01-01

    Detoxification of venom by radiation was investigated. Two concentrations i.e. 0.01% of venom solution were irradiated with different doses of gamma-radiations from cobalt-60 source. The results obtained indicate that the toxicity of venom is markedly attenuated by gamma-radiation. (author)

  9. Cobrotoxin from Naja naja atra Venom Ameliorates Adriamycin Nephropathy in Rats

    Shu-Zhi Wang

    2015-01-01

    Full Text Available Chronic kidney disease (CKD becomes a global health problem with high morbidity and mortality. Adriamycin- (ADR- induced rodent chronic nephropathy is a classic experimental model of human minimal lesion nephrotic syndrome. The present study investigated the effect of cobrotoxin (CTX on ADR-induced nephropathy. Rats were given 6 mg/kg ADR once through the tail vein to replicate ADR nephropathy model. CTX was administered to rats daily by placing a fast dissolving CTX membrane strip under the tongue starting from 5 days prior to ADR administration until the end of experiment. The results showed that CTX ameliorated the symptoms of ADR nephropathy syndrome with reduced body weight loss, proteinuria, hypoalbuminemia, dyslipidemia, serum electrolyte imbalance, oxidative stress, renal function abnormities, and kidney pathological lesions. Anti-inflammatory cytokine IL-10 expression was elevated after CTX administration in ADR nephropathy model. CTX inhibited the phosphorylation of IκB-α and NF-κB p65 nuclear translocation. Meanwhile, CTX upregulated the protein level of podocyte-specific nephrin and downregulated the level of fibrosis-related TGF-β. These findings suggest that CTX may be a potential drug for chronic kidney diseases.

  10. In vitro screening of snake venom against multidrug-resistant tuberculosis

    Sujay Kumar Bhunia

    2015-12-01

    Full Text Available The re-emergence of multidrug-resistant tuberculosis (MDR-TB has brought to light the importance of screening effective novel drugs. In the present study, in vitro activities of different snake (Naja naja, Bungarus fasciatus, Daboia russelli russelli, Naja kaouthia venoms have been investigated against clinical isolate of MDR-TB strains. The treatment with all the venoms inhibited the mycobacterial growth for at least a week in common and two of them (Naja naja and Naja kaouthia showed significantly longer inhibition up to two weeks against the MDR-TB strain with single dose and a repetition of those two venoms exhibited inhibition up to more than four weeks.

  11. A tropical tale: how Naja nigricollis venom beats Trypanosoma brucei

    Martos Esteban, Andrea; Laustsen, Andreas Hougaard; Carrington, Mark

    Trypanosoma brucei is a parasitic protozoan species capable to infecting insect vectors whose bite further produces African sleeping sickness inhuman beings [1]. During the parasite’s extracellular life in the mammalian host,its outer coat, mainly composed of Variable Surface Glycoproteins (VSGs)...

  12. Transnacional'naja territorial'naja transportnaja sistema Baltijskogo regiona [The transnational territorial transport system of the Baltic Region

    Gumenyuk Ivan

    2012-01-01

    Full Text Available In this paper we focus on the structure and territorial borders of the Baltic Sea region, and examine the key structural elements of the transnational territorial transport system. In this respect, we clarify some terms used in transport geography. For the first time the transport system gets territorially localized, which allows for a broad range of new studies of transnational transportation in the Baltic Sea area. We also identify the main principles of development and operation of international territorial transport systems and present them taking the Baltic Sea region as an example. Our findings, we hope, will have a great practical application for researchers of transport geography, especially those studying international logistics.

  13. Institucional'naja podgotovka Pol'shi k vstupleniju v Evropejskij sojuz

    Tomaszewski W.

    2015-05-01

    Full Text Available In May 2014 it was aready ten years since Poland’s accession to the European Union. The accession was preceded by a long period of political action and negotiations between the Polish and the EU institutions. The process of integration was extremely complex. It covered almost all areas of economic, legal and civil aspects of the aspiring country’s economy, in which all necessary requirements had to be met. The aim of the article was to present the institutional framework created for efficient implementation of the process of accession. The considerations involved especially an institutional method. The research resulted in poining out both the actually efficient and less efficient bodies participating in the process of integration.

  14. Protein Characterization of Javan Cobra (Naja sputatrix) Venom Following Sun Exposure and Photo-Oxidation Treatment

    Sulistiyani; Biki, R. S.; Andrianto, D.

    2017-03-01

    Snake venom has always been known for its toxicity that can cause fatality, however, it is also one of the important biological resources to be used for disease treatment. In Indonesia, snake venom previously expose under the sun has been used for alternative treatment of some diseases such as dengue fever, atherosclerosis, cancer, and diabetes. There has been very little scientific evidence on the use of snake venom of Indonesia origin as well as its protein characteristic. Thus, the objective of this research is to characterize the protein content and the specific activity of the venom of Javan Cobra (N.sputatrix) when treated with sun exposure in comparison with photo-oxidation by ultraviolet. Qualitative analysis of protein contents was determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). The L-amino acid oxidase activity (LAAO) and the phospholipase A2 (PLA2) activities were determined using spectrophotometry. The venom’s protein was separated into 5 main protein bands with molecular weight ranging from 14 to 108 kDa. A time course study showed that the venom lost 91% of its LAAO activity and 96% of PLA2 activity after 6 hours of sun exposure. UV photo-oxidation carried out for 3 hours decreased 91% of LAAO activity, and almost diminished all of PLA2 activity (99.8%). These findings suggest that the exposure of N. sputatrix venom under the sun and UV photo-oxidation decreased its toxicity as shown by the significant reduction of the enzymes activity, but did not affect the protein’s integrity. Therefore, these approaches produced N.sputatrix venom with less toxicity but still withheld other characters of intact proteins.

  15. Protein profile analysis of Malaysian snake venoms by two-dimensional gel electrophoresis

    J Vejayan

    2010-01-01

    Full Text Available Snake venoms comprise a highly complex mixture of proteins, which requires for their characterization the use of versatile two-dimensional electrophoresis techniques. In the present study, venoms obtained from eight snakes (Ophiophagus hannah, Naja kaouthia, Naja sumatrana, Bungarus fasciatus, Trimeresurus sumatranus, Tropidolaemus wagleri, Enhydrina schistosa and Calloselasma rhodostoma commonly found in Malaysia were separated based on two independent properties, isoelectric point (pI and molecular weight (MW. Many differences in snake venoms at the inter-family, inter-subfamily, inter-genus and inter-species levels were revealed. Notably, proteins from individuals of the Viperidae family - Trimeresurus sumatranus, Tropidolaemus wagleri and Calloselasma rhodostoma - were found to be numerous and scattered by the two-dimensional gel electrophoresis (2DE specifically in regions between 37 and 100 kDa compared to the Elapidae venom proteins. The latter were clustered at the basic and lower molecular mass region (less than 20 kDa. Trains of spots were commonly observed, indicating that these proteins may be derived from post-translational modifications. Ophiophagus hannah (Elapidae revealed a great amount of protein spots in the higher molecular mass range when compared to Enhydrina schistosa, Naja kaouthia, Naja sumatrana and Bungarus fasciatus. Overall 2DE showed large differences in the venom profile of each species, which might be employed as an ancillary tool to the identification of venomous snake species.

  16. Analisis Cemaran Staphylococcus aureus pada Gelas, Darah Segar, dan Jamu dengan Ramuan Darah Ular Kobra Jawa (Naja sputatrix

    Roza Azizah Primatika

    2017-01-01

    rerata cemaran Staphylococcus aureus menunjukkan tidak ada perbedaan antara swab gelas, darah dan ramuan darah ular kobra. Walaupun demikian, jamu yang mengandung darah ular kobra berpotensi mengandung Staphylococcus aureus yang membahayakan konsumen.

  17. Zimnij put’ u Puškina. (Nacional’naja priroda kuchnja istorii kak kul’tury)

    Ivanickij, Aleksandr

    1998-01-01

    In The Snowstorm, Captain's daughter and Eugene Onegin (chapter V, The dream of Tatyana) Pushkin's heroes of adventurous or sentimental novels are becoming partly fairy tales heroes and their roads in lives are receiving national and historical meaning. First, the adventurous way for the hero is laid by the fairy nature. Acting like a storm reforming the world, nature is continued in history (the 1812 war), or tallies with history (Pugachev's rebellion). The storm joins a...

  18. Gumanitaristika i socialnyje nauki v Češskoj respublike: transformacija i sovremennaja naučnaja politika

    Filáček, Adolf

    -, č. 8 (2008), s. 37-57 ISSN 1997-2806 Institutional research plan: CEZ:AV0Z90090514 Keywords : science policy * R&D transformation * European research area Subject RIV: AA - Philosophy ; Religion http://www.vei-21.ru/archiv/viss08.pdf

  19. Exploring the venom of the forest cobra snake: Toxicovenomics and antivenom profiling of Naja melanoleuca

    Lauridsen, Line P.; Laustsen, Andreas Hougaard; Lomonte, Bruno

    2017-01-01

    A toxicovenomic analysis of the venom of the forest cobra, N. melanoleuca, was performed, revealing the presence of a total of 52 proteins by proteomics analysis. The most abundant proteins belong to the three-finger toxins (3FTx) (57.1 wt%), which includes post-synaptically acting α-neurotoxins........ This toxicovenomic study identified the 3FTx group of α-neurotoxins in the venom of N. melanoleuca as the relevant targets to be neutralized....

  20. Snake venom neutralization by Indian medicinal plants (Vitex negundo and Emblica officinalis) root extracts.

    Alam, M I; Gomes, A

    2003-05-01

    The methanolic root extracts of Vitex negundo Linn. and Emblica officinalis Gaertn. were explored for the first time for antisnake venom activity. The plant (V. negundo and E. officinalis) extracts significantly antagonized the Vipera russellii and Naja kaouthia venom induced lethal activity both in in vitro and in vivo studies. V. russellii venom-induced haemorrhage, coagulant, defibrinogenating and inflammatory activity was significantly neutralized by both plant extracts. No precipitating bands were observed between the plant extract and snake venom. The above observations confirmed that the plant extracts possess potent snake venom neutralizing capacity and need further investigation.

  1. Discovery and optimization of peptide-based anti-cobratoxins

    Sola, M.; Laustsen, Andreas Hougaard; Johannesen, J.

    More than 5.5 million people per year are victims of snake envenomation, resulting in 125,000 deaths and 400,000amputations worldwide. Antivenoms are still produced by animal immunization procedures, and they areassociated with a high risk of severe adverse reactions. Alternatively, synthetic pep...... peptides may open the possibility for newtherapies with better efficacy and safety. Here, we report the discovery and optimization of a synthetic peptide directedagainst α-cobratoxin (α-CTX), the most toxic component of Monocled cobra (Naja kaouthia)....

  2. Mucuna pruriens Linn. seed extract pretreatment protects against cardiorespiratory and neuromuscular depressant effects of Naja sputatrix (Javan spitting cobra) venom in rats.

    Fung, Shin Yee; Tan, Nget Hong; Sim, Si Mui; Marinello, Enrico; Guerranti, Roberto; Aguiyi, John Chinyere

    2011-04-01

    Mucuna pruriens has been used by native Nigerians as a prophylactic for snakebite. The protective effects of M. pruriens seed extract (MPE) were investigated against the pharmacological actions of N. sputatrix (Javan spitting cobra) venom in rats. The results showed that MPE-pretreatment protected against cardiorespiratory and, to a lesser extent, neuromuscular depressant effects of N. sputatrix venom. These may be explained at least in part by the neutralisation of the cobra venom toxins by anti-MPE antibodies elicited by the MPE pretreatment.

  3. Demograficheskie izmenenija v Germanii i novaja territorial'naja struktura starenija [Demographic change in Germany and reversal of spatial ageing patterns

    Swiaczny Frank

    2010-01-01

    Full Text Available The paper presents the result of a spatial analysis considering the effect of demographic ageing and ageing-in-place processes in Germany according to spatially differentiated ageing patterns among urban, sub-urban and rural counties up to 2025. As to the latest official population forecast counties of urban core regions will undergo a slower ageing process than other types of counties, resulting in a reversal of ageing patterns. Urban core areas in this analysis will gain demographically from their net migration surplus while suburban housing locations of the past will be no longer able to attract enough young migrants to compensate for their now rapidly ageing baby boomer generation. The process presented is typical for the fate of (suburban housing areas with homogenous populations under conditions of ageing and shrinking if spatial mobility in ageing population groups is declining.

  4. Inhibition of the nicotinic acetylcholine receptors by cobra venom α-neurotoxins: is there a perspective in lung cancer treatment?

    Angela Alama

    Full Text Available Nicotine exerts its oncogenic effects through the binding to nicotinic acetylcholine receptors (nAChRs and the activation of downstream pathways that block apoptosis and promote neo-angiogenesis. The nAChRs of the α7 subtype are present on a wide variety of cancer cells and their inhibition by cobra venom neurotoxins has been proposed in several articles and reviews as a potential innovative lung cancer therapy. However, since part of the published results was recently retracted, we believe that the antitumoral activity of cobra venom neurotoxins needs to be independently re-evaluated.We determined the activity of α-neurotoxins from Naja atra (short-chain neurotoxin, α-cobrotoxin and Naja kaouthia (long-chain neurotoxin, α-cobratoxin in vitro by cytotoxicity measurements in 5 lung cancer cell lines, by colony formation assay with α7nAChRs expressing and non-expressing cell lines and in vivo by assessing tumor growth in an orthotopic Non-Obese Diabetic/Severe Combined Immunodeficient (NOD/SCID mouse model system utilizing different treatment schedules and dosages.No statistically significant reduction in tumor growth was observed in the treatment arms in comparison to the control for both toxins. Paradoxically α-cobrotoxin from Naja atra showed the tendency to enhance tumor growth although, even in this case, the statistical significance was not reached.In conclusion our results show that, in contrast with other reports, the nAChR inhibitors α-cobratoxin from N. kaouthia and α-cobrotoxin from N. atra neither suppressed tumor growth nor prolonged the survival of the treated animals.

  5. Hyaluronidase and protease activities from Indian snake venoms: neutralization by Mimosa pudica root extract.

    Girish, K S; Mohanakumari, H P; Nagaraju, S; Vishwanath, B S; Kemparaju, K

    2004-06-01

    The aqueous root extract of Mimosa pudica dose dependently inhibited the hyaluronidase and protease activities of Indian snakes (Naja naja, Vipera russelii and Echis carinatus) venom. Copyright 2004 Elsevier B.V.

  6. Quantifying Demyelination in NK venom treated nerve using its electric circuit model.

    Das, H K; Das, D; Doley, R; Sahu, P P

    2016-03-02

    Reduction of myelin in peripheral nerve causes critical demyelinating diseases such as chronic inflammatory demyelinating polyneuropathy, Guillain-Barre syndrome, etc. Clinical monitoring of these diseases requires rapid and non-invasive quantification of demyelination. Here we have developed formulation of nerve conduction velocity (NCV) in terms of demyelination considering electric circuit model of a nerve having bundle of axons for its quantification from NCV measurements. This approach has been validated and demonstrated with toad nerve model treated with crude Naja kaouthia (NK) venom and also shows the effect of Phospholipase A2 and three finger neurotoxin from NK-venom on peripheral nerve. This opens future scope for non-invasive clinical measurement of demyelination.

  7. Quantifying Demyelination in NK venom treated nerve using its electric circuit model

    Das, H. K.; Das, D.; Doley, R.; Sahu, P. P.

    2016-03-01

    Reduction of myelin in peripheral nerve causes critical demyelinating diseases such as chronic inflammatory demyelinating polyneuropathy, Guillain-Barre syndrome, etc. Clinical monitoring of these diseases requires rapid and non-invasive quantification of demyelination. Here we have developed formulation of nerve conduction velocity (NCV) in terms of demyelination considering electric circuit model of a nerve having bundle of axons for its quantification from NCV measurements. This approach has been validated and demonstrated with toad nerve model treated with crude Naja kaouthia (NK) venom and also shows the effect of Phospholipase A2 and three finger neurotoxin from NK-venom on peripheral nerve. This opens future scope for non-invasive clinical measurement of demyelination.

  8. Naučnaja korrespondencija v istorii češskoj slavistiki kak evrističeskaja problema (I. Polivka i F. Vollman v dialoge učitelja i učenika o metodologii specializacii)

    Zelenková, Anna

    2012-01-01

    Roč. 15, Supplementum 2 (2012), s. 223-235 ISSN 1212-1509 Institutional support: RVO:68378017 Keywords : Polívka, Jiří * Wollman, Frank * correspondence * Comenius University in Bratislava * comparative studies * literary history Subject RIV: AJ - Letters, Mass-media, Audiovision

  9. Blindness from spitting cobra venom: Case report | Atipo-Tsiba | East ...

    Spitting cobra is the name given to some snakes of the family of Elapidae, belonging to the genus Naja or Hemachatus that have the ability to spitt heir venom (up to 3m) to blind their predators. Naja mossambica is the most answered species in Africa.The precise statistics of attacks due to this snake are available, let alone ...

  10. BISA ULAR MENINGKATKAN DAYA FAGOSITOSIS MAKROFAG PERITONEUM MENCIT TERHADAP KUMAN STREPTOKOKUS GRUP B SNAKE VENOM ENHANCES THE PHAGOCYTIC CAPABILITY OF PERITONEAL MACROPHAGES OF MICE AGAINST THE GROUP B STREPTOCOCCUS

    Chandramaya Siska Damayanti

    2007-06-01

    Full Text Available Penelitian ini bertujuan mengetahui efek pemberian bisa ular tanah (Calloselasma rhodostoma, ular kobra (Naja naja sputatrix, dan ular welang Bungarus fasciatus pada daya fagositosis makrofag peritoneal mencit terhadap kuman streptokokus grup B. Mencit diberi berbagai dosis bisa ular secara peroral selama 7 hari atau secara intravena sebanyak 3 kali dengan selang waktu penyuntikan 3 hari sekali. Di akhir percobaan

  11. Venom-gland transcriptome and venom proteome of the Malaysian king cobra (Ophiophagus hannah).

    Tan, Choo Hock; Tan, Kae Yi; Fung, Shin Yee; Tan, Nget Hong

    2015-09-10

    The king cobra (Ophiophagus hannah) is widely distributed throughout many parts of Asia. This study aims to investigate the complexity of Malaysian Ophiophagus hannah (MOh) venom for a better understanding of king cobra venom variation and its envenoming pathophysiology. The venom gland transcriptome was investigated using the Illumina HiSeq™ platform, while the venom proteome was profiled by 1D-SDS-PAGE-nano-ESI-LCMS/MS. Transcriptomic results reveal high redundancy of toxin transcripts (3357.36 FPKM/transcript) despite small cluster numbers, implying gene duplication and diversification within restricted protein families. Among the 23 toxin families identified, three-finger toxins (3FTxs) and snake-venom metalloproteases (SVMPs) have the most diverse isoforms. These 2 toxin families are also the most abundantly transcribed, followed in descending order by phospholipases A2 (PLA2s), cysteine-rich secretory proteins (CRISPs), Kunitz-type inhibitors (KUNs), and L-amino acid oxidases (LAAOs). Seventeen toxin families exhibited low mRNA expression, including hyaluronidase, DPP-IV and 5'-nucleotidase that were not previously reported in the venom-gland transcriptome of a Balinese O. hannah. On the other hand, the MOh proteome includes 3FTxs, the most abundantly expressed proteins in the venom (43 % toxin sbundance). Within this toxin family, there are 6 long-chain, 5 short-chain and 2 non-conventional 3FTx. Neurotoxins comprise the major 3FTxs in the MOh venom, consistent with rapid neuromuscular paralysis reported in systemic envenoming. The presence of toxic enzymes such as LAAOs, SVMPs and PLA2 would explain tissue inflammation and necrotising destruction in local envenoming. Dissimilarities in the subtypes and sequences between the neurotoxins of MOh and Naja kaouthia (monocled cobra) are in agreement with the poor cross-neutralization activity of N. kaouthia antivenom used against MOh venom. Besides, the presence of cobra venom factor, nerve growth factors

  12. Evaluation of the mechanism of skin enhancing surfactants on the biomembrane of shed snake skin.

    Wonglertnirant, Nanthida; Ngawhirunpat, Tanasait; Kumpugdee-Vollrath, Mont

    2012-01-01

    The aim of the present work was to investigate the effects of different surfactants at various concentrations as a skin penetration enhancer through the biomembrane of the shed skin of Naja kaouthia. Additionally, the enhancer mechanism(s) of each class of surfactants were evaluated using physical characterization techniques, such as scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and small and wide angle X-ray scattering (SWAXS). Our results showed that skin permeability increased with increasing concentrations of surfactants and the degree of increase was higher for the model hydrophilic permeant, deuterium dioxide (D(2)O), than the lipophilic permeant, ketoprofen (KP). Ionic surfactants, sodium lauryl sulfate (SLS) and cetyl trimethyl ammonium bromide (CTAB), demonstrated higher enhancement ability than the polyoxyethylene (20) sorbitan mono-oleate (Tween 80) non-ionic surfactant, which was consistent with the results from physical characterization studies. Increasing amounts of permeated drug resulted in an increase in membrane interactions. From our observations, it can be assumed that SLS and CTAB can be localized inside the biomembrane and thereby enhance drug permeation mainly through interactions with intercellular lipids in the stratum corneum (SC) and the creation of a perturbed microenvironment among lipid alkyl chains and polar head groups.

  13. Nõukogude Liidu kõige kaunimad näitlejannad : Kümme portreed ja lühikest biograafiat = Самые красивые актрисы Советского Союза : Десять портретов и кратких биографий

    2009-01-01

    Vene näitlejannade Irina Alferova, Anastassia Vertinskaja, Tatjana Doronina, Irina Mirošnitšenko, Ljubov Orlova, Tatjana Samoilova, Anna Samohhina, Svetlana Svetlitšnaja, Margarita Terehhova ja Natalja Fatejeva lühibiograafiad

  14. Zone Denmark - gasell Taanist / Reet Krause

    Krause, Reet, 1967-

    2006-01-01

    Taanis Viborgis asuva firma Zone Company Denmark, kaubamärgi Zone Denmark ja firma disainerite tutvustus. Ettevõte valmistab disainitooteid roostevabast terasest, klaasist, puidust, kummist jm. Disainer Naja Utzon Popov endast, oma loomingust

  15. SNAKE BITE WITH TOXIC DEMYELINATION – A CASE REPORT

    Justin

    2016-02-01

    Full Text Available INTRODUCTION Snakebite is an important cause of mortality and morbidity in India. India has the highest number of deaths due to snake bite1 Neurotoxicity due to snakebite is well-known with varied presentation.2 Common cases of snakebites are of saw-scaled viper (Echis carinatus, Russell’s viper (a viperidae, krait (Bungarus caeruleus, common cobra (Naja naja king cobra (Ophiophagus hannah.3

  16. Influence of aquatic plants on the predation of Piaractus mesopotamicus larvae by Pantala flavescens - doi: 10.4025/actascibiolsci.v32i2.5167 Influence of aquatic plants on the predation of Piaractus mesopotamicus larvae by Pantala flavescens - doi: 10.4025/actascibiolsci.v32i2.5167

    Carlos Eduardo Bento Fernandes

    2010-05-01

    Full Text Available The experiment aimed to study the influence of the aquatic plants E. najas, P. stratiotes and S. auriculata on the predation of P. mesopotamicus larvae by P. flavescens. One hundred and twenty larvae of P. mesopotamicus and 24 larvae of P. flavescens were placed in 24 aquariums with capacity of 12 L, with one Odonate per aquarium. Treatments were different regarding the species of aquatic plants E. najas, S. auriculata and P. stratiotes, with one control treatment without aquatic plants. One aquarium (12 L containing one Odonate and 30 P. mesopotamicus larvae was considered one experimental unit. After 18 hours, the Odonates were removed from the aquariums and fish larvae left (alive were counted in each experimental unit. The survival rate of P. mesopotamicus larvae in the treatment without aquatic plants (control was significantly lower than in the treatment with E. najas. However, the survival rates in the aquariums with floating aquatic plants did not differ from the control. The morphological characteristics of E. najas promoted higher structural complexity in the environment, offering more protection to the fish larvae, and increasing their survival. We concluded that the presence of the submerged aquatic plant E. najas promoted the reduction of predation of P. mesopotamicus larvae by Pantala flavescens. Larvae; Piaractus mesopotamicus; Pantala flavescens; predation; aquatic plantsThe experiment aimed to study the influence of the aquatic plants E. najas, P. stratiotes and S. auriculata on the predation of P. mesopotamicus larvae by P. flavescens. One hundred and twenty larvae of P. mesopotamicus and 24 larvae of P. flavescens were placed in 24 aquariums with capacity of 12 L, with one Odonate per aquarium. Treatments were different regarding the species of aquatic plants E. najas, S. auriculata and P. stratiotes, with one control treatment without aquatic plants. One aquarium (12 L containing one Odonate and 30 P. mesopotamicus larvae was

  17. In Vivo Neutralization of α-Cobratoxin with High-Affinity Llama Single-Domain Antibodies (VHHs) and a VHH-Fc Antibody

    Richard, Gabrielle; Meyers, Ashley J.; McLean, Michael D.; Arbabi-Ghahroudi, Mehdi; MacKenzie, Roger; Hall, J. Christopher

    2013-01-01

    Small recombinant antibody fragments (e.g. scFvs and VHHs), which are highly tissue permeable, are being investigated for antivenom production as conventional antivenoms consisting of IgG or F(ab’)2 antibody fragments do not effectively neutralize venom toxins located in deep tissues. However, antivenoms composed entirely of small antibody fragments may have poor therapeutic efficacy due to their short serum half-lives. To increase serum persistence and maintain tissue penetration, we prepared low and high molecular mass antivenom antibodies. Four llama VHHs were isolated from an immune VHH-displayed phage library and were shown to have high affinity, in the low nM range, for α-cobratoxin (α–Cbtx), the most lethal component of Naja kaouthia venom. Subsequently, our highest affinity VHH (C2) was fused to a human Fc fragment to create a VHH2-Fc antibody that would offer prolonged serum persistence. After in planta (Nicotiana benthamiana) expression and purification, we show that our VHH2-Fc antibody retained high affinity binding to α–Cbtx. Mouse α–Cbtx challenge studies showed that our highest affinity VHHs (C2 and C20) and the VHH2-Fc antibody effectively neutralized lethality induced by α–Cbtx at an antibody:toxin molar ratio as low as ca. 0.75×:1. Further research towards the development of an antivenom therapeutic involving these anti-α-Cbtx VHHs and VHH2-Fc antibody molecules should involve testing them as a combination, to determine whether they maintain tissue penetration capability and low immunogenicity, and whether they exhibit improved serum persistence and therapeutic efficacy. PMID:23894495

  18. Snake cytotoxins bind to membranes via interactions with phosphatidylserine head groups of lipids.

    Anastasia G Konshina

    Full Text Available The major representatives of Elapidae snake venom, cytotoxins (CTs, share similar three-fingered fold and exert diverse range of biological activities against various cell types. CT-induced cell death starts from the membrane recognition process, whose molecular details remain unclear. It is known, however, that the presence of anionic lipids in cell membranes is one of the important factors determining CT-membrane binding. In this work, we therefore investigated specific interactions between one of the most abundant of such lipids, phosphatidylserine (PS, and CT 4 of Naja kaouthia using a combined, experimental and modeling, approach. It was shown that incorporation of PS into zwitterionic liposomes greatly increased the membrane-damaging activity of CT 4 measured by the release of the liposome-entrapped calcein fluorescent dye. The CT-induced leakage rate depends on the PS concentration with a maximum at approximately 20% PS. Interestingly, the effects observed for PS were much more pronounced than those measured for another anionic lipid, sulfatide. To delineate the potential PS binding sites on CT 4 and estimate their relative affinities, a series of computer simulations was performed for the systems containing the head group of PS and different spatial models of CT 4 in aqueous solution and in an implicit membrane. This was done using an original hybrid computational protocol implementing docking, Monte Carlo and molecular dynamics simulations. As a result, at least three putative PS-binding sites with different affinities to PS molecule were delineated. Being located in different parts of the CT molecule, these anion-binding sites can potentially facilitate and modulate the multi-step process of the toxin insertion into lipid bilayers. This feature together with the diverse binding affinities of the sites to a wide variety of anionic targets on the membrane surface appears to be functionally meaningful and may adjust CT action against

  19. Assessment of macro and microelement accumulation capability of two aquatic plants

    Baldantoni, Daniela; Alfani, Anna; Di Tommasi, Paul; Bartoli, Giovanni; De Santo, Amalia Virzo

    2004-01-01

    The concentrations of four macroelements (C, N, P, S) and eight trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) were measured in the leaves and roots of the emergent plant, Phragmites communis Trin., and in the shoots and roots of the submersed Najas marina L., taken from Lake Averno (Naples, Italy). Phragmites communis leaves showed higher concentrations of carbon, nitrogen and phosphorus than roots, while the roots exhibited significantly higher concentrations of sulphur and trace metals. Najas marina roots also showed higher concentrations of sulphur and trace metals than shoots, but these differences were less marked than in Phragmites communis except for sulphur. Sulphur was the only macronutrient to show the highest concentrations in the roots. Phragmites communis roots had higher values of Cr, Cu, Fe, Mn and Ni than Najas marina roots. By contrast, Cd, Cr, Fe, Ni, Pb and Zn concentrations were higher in Najas marina shoots than in Phragmites communis leaves. Phragmites communis, available through the year, showing high capability to accumulate trace metals in the roots, appears a good monitor of lake contamination, better than Najas marina. - Element accumulation in roots and shoots of aquatic plants was used as a criteria for selecting useful biomonitors

  20. Evaluation of butachlor for control of some submerged macrophytes along with its impact on biotic components of freshwater system

    A. Chattopadhyay, S. Adhikari, S. P. Adhikary, S. Ayyappan

    2006-04-01

    Full Text Available In this investigation, the efficacy of the herbicide butachlor, (N-butoxymethyl-2 chloro-21, 61 diethyl acetanilide was tested against few common submerged macrophytes namely Hydrilla (Hydrilla verticillata (L. Royale, Najas (Najas minor All., Nechamandra (Nechamandra alternifolia (Roxb. Thwaites and Ottelia (Ottelia alismoides (L. Pers. of freshwater fish ponds. Almost complete decay of Hydrilla, Nechamandra and Ottelia was achieved at 7.5 L of active ingredient/ha/m butachlor within 15 days while the herbicide showed no negative effect on Najas. However at the same concentration of butachlor, total mortality of zooplankton and water fern Azolla (Azolla caroliniana Lamarck occurred within seven days. In case of few freshwater fish species like Rohu (Labeo rohita, Channa (Channa punctatus, Anabas (Anabas testitudineus and Heteropneustes (Heteropneustes fossilis, total mortality occurred upto 90 days after application of the same dose of butachlor but fish survived beyond 120 days of herbicide application indicating degradation of the herbicides.

  1. An Experimental Study for Improving Snake Antivenin Production Using Gamma Radiation and a Biotechnological Technique

    Mohamed, H.K.

    2015-01-01

    Snake-bite is considered a neglected tropical disease that affects thousands of people worldwide. Administration of antivenom is the corner stone in the therapy of snake-bite. The study aimed to improve the production of antivenom using gamma irradiation to detoxify venom and calcium phosphate nanoparticles as alternative adjuvant. This was carried out by studying the toxicological and immunological properties of the Naja haje venom before and after exposure to 2 KGy gamma radiation. Calcium phosphate nanoparticles were selected to be used as adjuvant as they showed better entrapment efficacy than Alum or chitosan nanoparticles. In order to achieve the goal of the present study, the native, γ irradiated and nanoparticles loaded venom as well nanoparticles loaded irradiated venom were used for preparation of their specific antivenom using rabbits. Data revealed that gamma irradiation of Naja haje venom reduced its lethality to one sixth as compared to its native venom. There was no change in the antigenic reactivity between both native and γ irradiated Naja haje venoms. Inhibition in the phospholipase and proteolytic activities after gamma irradiation were shown. Furthermore, injection of γ irradiated Naja haje venom did not significantly change activities of serum LDH, CPK, CK-MB, ALT and AST as well as urea and creatinine levels compared to the normal group. In addition, the immune response of immunized rabbits was evaluated through determination of antibody titer using ELISA technique, serum titer produced with γ irradiated venom loaded on CPN showed highest titer as compared to other sera. Results indicated that the sooner antivenom was injected the higher the neutralizing capacity obtained. All the prepared antivenoms were able to neutralize the toxicological activities of Naja haje snake venom to same extent. Thus, gamma radiation is a reliable tool for detoxification of Naja haje venom without affecting its immunogenicity. Furthermore. Calcium phosphate

  2. Analyses of venom spitting in African cobras (Elapidae: Serpentes ...

    ... all four species. The low levels of variation in venom volume, coupled with the variation in venom dispersal pattern, suggests a complexity to the regulation of venom flow in spitting cobras beyond simply neuromuscular control of the extrinsic venom gland. Keywords: defensive behaviour, snake, teeth, Naja, Hemachatus ...

  3. The Antinociceptive Effects of Iranian Cobra Snake Venom using Formalin Test

    Zahra Hadi Chegeni

    2015-06-01

    Full Text Available Abstract Background: There have been numerous reports of snake venoms being employed as analgesics in attempts to relieve severe pain associated with cancer, immune dysfunction and viral infections. This study investigates the antinociceptive effects of iranian cobra snake venom (Naja naja oxiana in comparison with morphine and lidocain on laboratorial femal mice. Materials and Methods: This study has been done on 48 NMRI female mice of 18-20 g in weight. Antinociceptive activeity of snake venom was evaluated by formalin test. In this test, the animals were divided into 6 groups (each group consisting of 8 mice: Sham, positive Control (receiving morphine at dose of 5 mg/kg, and receiving lidocain at dose of 20 mg/kg, and experimental groups receiving venom at doses of 1, 3 and 4/5 µg/mice. In all groups, the formalin test was recorded for 60 min after administration of venom and drugs in mice. Data were analyzed using one-way ANOVA and Tukey test. Results: The results showed that the venom of Naja naja oxiana decreased nociception meaningfully in both acute and chronic phases. We also showed that this venom revealed even a better analgesic activity in comparison with morphine and lidocain. Conclusion: This study showed that the antinociceptive effect of the venom was mediated through central nervous system and peripheral mechanisms. Although details of the mechanism remain unclear, and further studies should be considered to demonstrate its therapeutic effects.

  4. Use of Pavo cristatus feather extract for the better management of snakebites: neutralization of inflammatory reactions.

    Murari, Satish K; Frey, Felix J; Frey, Brigitte M; Gowda, There V; Vishwanath, Bannikuppe S

    2005-06-03

    In Indian traditional medicine, peacock feather in the form of ash (Bhasma) or water extract are used against snakebite and to treat various problems associated with lungs. This study was aimed to evaluate the water extract of peacock feather (PCF) against the local tissue damage caused due to snakebite. PCF water extract showed inhibition towards phospholipase A2 enzyme activity from snake venom (Naja naja and Vipera russelii), inflammatory fluids (synovial, pleural, ascites) and normal serum in a dose-dependent manner. Hyaluronidase and proteases are other major enzymes in snake venoms responsible for local tissue damage. PCF water extract inhibited hyaluronidase and proteolytic enzyme activities from Vipera russelii, Naja naja and Trimeresurus malabaricus venom. The active principle is a hydrophilic molecule easily extractable in water or polar solvents. PCF water extract gave positive results for the presence of protein and secondary metabolites like carotenoids and steroids. Analysis of metal ions revealed that iron is the major ion (> 20-fold). Other metal ions detected in smaller amount are copper, chromium, zinc and nickel. The least amount of ion detected is gold. Co-injection of PCF water extract with snake venom and inflammatory PLA2 enzymes neutralize the edema inducing activity of all the PLA2 enzymes studied. Since it inhibits hyaluronidase and proteases enzyme activity from snake venom PCF water extract is a powerful neutralizing agent, which has therapeutic application against venom toxicity.

  5. Snake venom instability | Willemse | African Zoology

    Egyptian cobra Naja haje haje) and puffadder (Bills arietans). Considerable differences in electrophoretic characteristics were found between fresh venom and commercial venom samples from the same species of snake. These differences could be attributed partly to the instability of snake venom under conditions of drying ...

  6. Nieuwe vondsten van zeldzame planten in 1991 en 1992

    Meijden, van der R.; Holverda, W.J.; Vermeulen, J.J.; Weeda, E.J.

    1994-01-01

    Najas minor was found again after 85 years of absence. Four species have for the first time crossed the border of the Netherlands, while extending their range: Bidens radiata, Bupleurum falcatum, Callitriche brutia, and Scirpus holoschoenus. Possible recent immigrants are Hypericum androsaemum,

  7. Effect of quarrying activity on biodiversity: Case study of Ogbere site ...

    These range from families like Veranidae: black cobra Naja melanloeuca, Elaphidae, Agama agama and Python with 1.8/km each. A total number of thirty two species of avi-fauna varieties were sampled at the site, ranging from different families and species mostly fund are the clusters of villageweavers Ploceus cucullatus ...

  8. Classifying snakebite in South Africa: Validating a scoring system

    There are some 38 venomous snake species in South Africa (SA), of which approximately half are dangerous to humans.[1] Snake species and density vary across the regions of SA.[2] Prevalent species include the Mozambique spitting cobra (Naja mossambica) and puff adder. (Bitis arietans), an elapid and viperid ...

  9. Hemostatic interference of Indian king cobra (Ophiophagus hannah) Venom. Comparison with three other snake venoms of the subcontinent.

    Gowtham, Yashonandana J; Kumar, M S; Girish, K S; Kemparaju, K

    2012-06-01

    Unlike Naja naja, Bungarus caeruleus, Echis carinatus, and Daboia/Vipera russellii venoms, Ophiophagus hannah venom is medically ignored in the Indian subcontinent. Being the biggest poisonous snake, O. hannah has been presumed to inject several lethal doses of venom in a single bite. Lack of therapeutic antivenom to O. hannah bite in India makes any attempt to save the victim a difficult exercise. This study was initiated to compare O. hannah venom with the above said venoms for possible interference in hemostasis. Ophiophagus hannah venom was found to actively interfere in hemostatic stages such as fibrin clot formation, platelet activation/aggregation, and fibrin clot dissolution. It decreased partial thromboplastin time (aPTT), prothrombin time (PT), and thrombin clotting time (TCT). These activities are similar to that shown by E. carinatus and D. russellii venoms, and thus O. hannah venom was found to exert procoagulant activity through the common pathway of blood coagulation, while N. naja venom increased aPTT and TCT but not PT, and hence it was found to exert anticoagulant activity through the intrinsic pathway. Venoms of O. hannah, E. carinatus, and D. russellii lack plasminogen activation property as they do not hydrolyze azocasein, while they all show plasmin-like activity by degrading the fibrin clot. Although N. naja venom did not degrade azocasein, unlike other venoms, it showed feeble plasmin-like activity on fibrin clot. Venom of E. carinatus induced clotting of human platelet rich plasma (PRP), while the other three venoms interfered in agonist-induced platelet aggregation in PRP. Venom of O. hannah least inhibited the ADP induced platelet aggregation as compared to D. russellii and N. naja venoms. All these three venoms showed complete inhibition of epinephrine-induced aggregation at varied doses. However, O. hannah venom was unique in inhibiting thrombin induced aggregation.

  10. Iodine and tritium labelling of curarizing and cardiotoxic agents. Study of the conformation of toxic polypeptides extracted from snake venom

    Menez, Andre.

    1977-01-01

    A short review of present-day knowledge on the action mechanism of toxic snake venom polypeptides is followed by a study of the radioactive labelling of some toxic compounds. Those dealt with more especially are Naja nigricollis α toxin and Laticauda semifasciata b erabutoxin, then (+) tubocurarin, a non-peptidic curarizing alkaloid, and two cardiotoxic polypeptides: cytotoxin II and cardiotoxin γ extracted from the venom of Naja naja and Naja nigricollis respectively. The labelling principle is based on the specific fixation of one or more iodine atoms then tritium substitution of the halogen by catalytic hydrogenolysis. As predicted from titration of the aromatic groups the halogenation process, obtained by addition of iodine monochloride, takes place sometimes on the phenolic nuclei and sometimes on the imidazole nuclei, the position of which targets within each sequence has been identified. From results of the study of reactivity towards iodine combined with those of basic titration, the accessibility of several aromatic nuclei has also been defined. Each iodinated polypeptide is then hydrogenolysed in the presence of tritium gas giving a specific activity between 4 and 27 Ci/mmole according to the compound treated. In all cases the biological potential and physical properties of the radioactive material obtained by the above titration process remained intact. An example of the bonding kinetics of short toxins with the partially purified choligenic receptor is given in the special case of tritiated b erabutoxin. The affinity of this toxin for its receptor target is strong, though slightly less so than that of tritiated Naja nigricollis α toxin [fr

  11. Isolation and characterization of bioactive compounds of Clematis gouriana Roxb. ex DC against snake venom phospholipase A2 (PLA2) computational and in vitro insights.

    Muthusamy, Karthikeyan; Chinnasamy, Sathishkumar; Nagarajan, Subbiah; Sivaraman, Thirunavukkarasu; Chinnasamy, Selvakumar

    2017-07-01

    Bioactive compounds were isolated from Clematis gouriana Roxb. ex DC. The compounds were separated, characterized, the structures elucidated and submitted to the PubChem Database. The PubChem Ids SID 249494134 and SID 249494135 were tested against phospholipases A 2 (PLA 2 ) of Naja naja (Indian cobra) venom for PLA 2 activity. Both the compounds showed promising inhibitory activity; computational data also substantiated the results. The two compounds underwent density functional theory calculation to observe the chemical stability and electrostatic potential profile. Molecular interactions between the compounds and PLA 2 were observed at the binding pocket of the PLA 2 protein. Further, this protein-ligand complexes were simulated for a timescale of 100 ns of molecular dynamics simulation. Experimental and computational results showed significant PLA 2 inhibition activity.

  12. Prevalence of snake bites in Kangar District Hospital, Perlis, west Malaysia: a retrospective study (January 1999-December 2000).

    Jamaiah, I; Rohela, M; Roshalina, R; Undan, R C

    2004-12-01

    The records of 284 snake bite cases presenting to the Kangar District Hospital, Perlis, west Malaysia, from January 1999 till December 2000 were carefully reviewed. Data on prevalence and types of snake bites, were recorded. The majority of the cases were among Malays (60.2%), followed by Chinese (16.9%), Indians (13%), and others which include Thai nationals, army personnel from Sabah and Sarawak, and foreign tourists (9.8%). A higher incidence was found in males (60.2%) and most cases were seen in the age group of 10-19 years (33%). Snake bites were more common between 2 PM and 9 PM (47.6%) and from 7 AM to 2 PM (33.4%). The snakes were positively identified in 68 cases, of which 50 were common cobras (Naja naja) (73%), 16 were Malayan pit vipers (Agkistrodon rhodostoma) (24%) and two were sea-snakes (3%).

  13. Alum application to improve water quality in a municipal wastewater treatment wetland: Effects on macrophyte growth and nutrient uptake

    Malecki-Brown, Lynette M.; White, John R.; Brix, Hans

    2010-01-01

    Application of low doses of alum to treatment wetlands to reduce elevated outflow winter phosphorus concentrations were tested in mesocosms vegetated with either Typha domingensis, Schoenoplectus californicus, or submerged aquatic vegetation (SAV) (Najas guadalupensis-dominated). Alum was pumped......-treated SAV as compared to the control, and in Typha and Schoenoplectus the concentrations were 4- and 2-fold, higher, respectively. The N/P ratios in the plant tissues were low (

  14. Public health aspects of snakebite care in West Africa: perspectives from Nigeria

    Habib, Abdulrazaq G

    2013-01-01

    Snakebite envenoming is a major public health problem among rural communities of the Nigerian savanna. The saw-scaled or carpet viper (Echis ocellatus) and, to a lesser extent, the African cobras (Naja spp.) and puff adders (Bitis arietans) have proved to be the most important cause of mortality and morbidity. The main clinical features of E. ocellatus envenoming are systemic hemorrhage, incoagulable blood, shock, local swelling, bleeding and, occasionally, necrosis. Bites may be complicated ...

  15. Les morsures de serpent en milieux pédiatriques à l'hôpital de l ...

    FAV-Afrique) actif sur les espèces Bitis, Echis, Naja et Dendroaspis de Sanofi Pasteur couplé au besoin d'un traitement symptomatique. Résultats: Un total de 56 dossiers de patients (sex-ratio 1,6; âge moyen = 9,36 ± 3,66 ans) ont été colligés ...

  16. The protective effect of Mucuna pruriens seeds against snake venom poisoning.

    Tan, Nget Hong; Fung, Shin Yee; Sim, Si Mui; Marinello, Enrico; Guerranti, Roberto; Aguiyi, John C

    2009-06-22

    The seed, leaf and root of Mucuna pruriens have been used in traditional medicine for treatments of various diseases. In Nigeria, the seed is used as oral prophylactics for snakebite. To study the protective effects of Mucuna pruriens seed extract against the lethalities of various snake venoms. Rats were pre-treated with Mucuna pruriens seed extract and challenged with various snake venoms. The effectiveness of anti-Mucuna pruriens (anti-MPE) antibody to neutralize the lethalities of snake venoms was investigated by in vitro neutralization. In rats, MPE pre-treatment conferred effective protection against lethality of Naja sputatrix venom and moderate protection against Calloselasma rhodostoma venom. Indirect ELISA and immunoblotting studies showed that there were extensive cross-reactions between anti-MPE IgG and venoms from many different genera of poisonous snakes, suggesting the involvement of immunological neutralization in the protective effect of MPE pre-treatment against snake venom poisoning. In vitro neutralization experiments showed that the anti-MPE antibodies effectively neutralized the lethalities of Asiatic cobra (Naja) venoms, but were not very effective against other venoms tested. The anti-MPE antibodies could be used in the antiserum therapy of Asiatic cobra (Naja) bites.

  17. How the Cobra Got Its Flesh-Eating Venom: Cytotoxicity as a Defensive Innovation and Its Co-Evolution with Hooding, Aposematic Marking, and Spitting.

    Panagides, Nadya; Jackson, Timothy N W; Ikonomopoulou, Maria P; Arbuckle, Kevin; Pretzler, Rudolf; Yang, Daryl C; Ali, Syed A; Koludarov, Ivan; Dobson, James; Sanker, Brittany; Asselin, Angelique; Santana, Renan C; Hendrikx, Iwan; van der Ploeg, Harold; Tai-A-Pin, Jeremie; van den Bergh, Romilly; Kerkkamp, Harald M I; Vonk, Freek J; Naude, Arno; Strydom, Morné A; Jacobsz, Louis; Dunstan, Nathan; Jaeger, Marc; Hodgson, Wayne C; Miles, John; Fry, Bryan G

    2017-03-13

    The cytotoxicity of the venom of 25 species of Old World elapid snake was tested and compared with the morphological and behavioural adaptations of hooding and spitting. We determined that, contrary to previous assumptions, the venoms of spitting species are not consistently more cytotoxic than those of closely related non-spitting species. While this correlation between spitting and non-spitting was found among African cobras, it was not present among Asian cobras. On the other hand, a consistent positive correlation was observed between cytotoxicity and utilisation of the defensive hooding display that cobras are famous for. Hooding and spitting are widely regarded as defensive adaptations, but it has hitherto been uncertain whether cytotoxicity serves a defensive purpose or is somehow useful in prey subjugation. The results of this study suggest that cytotoxicity evolved primarily as a defensive innovation and that it has co-evolved twice alongside hooding behavior: once in the Hemachatus + Naja and again independently in the king cobras ( Ophiophagus ). There was a significant increase of cytotoxicity in the Asian Naja linked to the evolution of bold aposematic hood markings, reinforcing the link between hooding and the evolution of defensive cytotoxic venoms. In parallel, lineages with increased cytotoxicity but lacking bold hood patterns evolved aposematic markers in the form of high contrast body banding. The results also indicate that, secondary to the evolution of venom rich in cytotoxins, spitting has evolved three times independently: once within the African Naja , once within the Asian Naja , and once in the Hemachatus genus. The evolution of cytotoxic venom thus appears to facilitate the evolution of defensive spitting behaviour. In contrast, a secondary loss of cytotoxicity and reduction of the hood occurred in the water cobra Naja annulata , which possesses streamlined neurotoxic venom similar to that of other aquatic elapid snakes (e.g., hydrophiine

  18. How the Cobra Got Its Flesh-Eating Venom: Cytotoxicity as a Defensive Innovation and Its Co-Evolution with Hooding, Aposematic Marking, and Spitting

    Nadya Panagides

    2017-03-01

    Full Text Available The cytotoxicity of the venom of 25 species of Old World elapid snake was tested and compared with the morphological and behavioural adaptations of hooding and spitting. We determined that, contrary to previous assumptions, the venoms of spitting species are not consistently more cytotoxic than those of closely related non-spitting species. While this correlation between spitting and non-spitting was found among African cobras, it was not present among Asian cobras. On the other hand, a consistent positive correlation was observed between cytotoxicity and utilisation of the defensive hooding display that cobras are famous for. Hooding and spitting are widely regarded as defensive adaptations, but it has hitherto been uncertain whether cytotoxicity serves a defensive purpose or is somehow useful in prey subjugation. The results of this study suggest that cytotoxicity evolved primarily as a defensive innovation and that it has co-evolved twice alongside hooding behavior: once in the Hemachatus + Naja and again independently in the king cobras (Ophiophagus. There was a significant increase of cytotoxicity in the Asian Naja linked to the evolution of bold aposematic hood markings, reinforcing the link between hooding and the evolution of defensive cytotoxic venoms. In parallel, lineages with increased cytotoxicity but lacking bold hood patterns evolved aposematic markers in the form of high contrast body banding. The results also indicate that, secondary to the evolution of venom rich in cytotoxins, spitting has evolved three times independently: once within the African Naja, once within the Asian Naja, and once in the Hemachatus genus. The evolution of cytotoxic venom thus appears to facilitate the evolution of defensive spitting behaviour. In contrast, a secondary loss of cytotoxicity and reduction of the hood occurred in the water cobra Naja annulata, which possesses streamlined neurotoxic venom similar to that of other aquatic elapid snakes (e

  19. Enhanced recovery after surgery and video-assisted thoracic surgery lobectomy: the Italian VATS Group**List of collaborators of the Italian ERAS Group: Jacopo Vannucci, MD (University of Perugia); Antonio D’Andrilli, MD (S. Andrea Hospital, Roma); Majed Refai, MD (Ospedali Riuniti, Ancona); Guendalina Graffigna, MD (Università Cattolica del Sacro Cuore, Milano); Stefano Lovadina, MD (Ospedali Riuniti, Trieste); Marzia Umari (Ospedali Riuniti, Trieste), Paolo Ferrari, MD (IRCCS ISMETT-UPMC, University of Pittsburgh, Palermo); Michele Zuliani, MD (Ospedali Riuniti, Trieste); Marco Taurchini, MD (Casa Sollievo della Sofferenza, San Giovanni Rotondo); Carlo Del Naja, MD (Casa Sollievo della Sofferenza, San Giovanni Rotondo); Domenico Massullo, MD (S. Andrea Hospital, Roma), Olha Putina, MD (ASST Mantova), Nicoletta Pia Ardò (University of Foggia). surgical protocol

    Viggiano, Domenico; Voltolini, Luca; Bertani, Alessandro; Bertolaccini, Luca; Crisci, Roberto; Droghetti, Andrea

    2018-01-01

    Enhanced recovery after surgery (ERAS®) is a strategy that seeks to reduce patients’ perioperative stress response, thereby reducing potential complications, decreasing hospital length of stay and enabling patients to return more quickly to their baseline functional status. The concept was introduced in the late 1990s and was first adopted in patients undergoing open colorectal surgery. Since then, the concept of ERAS has been adopted by multiple surgical specialties. The diffusion of video-assisted thoracic surgery lobectomy (VATS-L) sets also the surgical treatment of lung cancer as a new area for ERAS development. In this paper, we present the Italian VATS Group (www.vatsgroup.org) surgical protocol as part of the ERAS clinical pathway belonging to the VATS-L national database. PMID:29629203

  20. Eficiência de fluridone no controle de plantas aquáticas submersas no reservatório de Jupiá Fluridone efficacy for control of submersed aquatic weeds in the Jupiá reservoir

    D.A.S. Marcondes

    2003-01-01

    Full Text Available O objetivo deste estudo foi avaliar a eficiência do herbicida fluridone no controle de plantas aquáticas submersas (Egeria densa, Egeria najas e Ceratophyllum demersum que ocorrem no reservatório da Usina Hidrelétrica Eng. Souza Dias (Jupiá, região noroeste do Estado de São Paulo. A pesquisa, que consistiu de aplicações de fluridone, foi conduzida em lagoas marginais do rio Tietê, denominadas Flórida e Barrenta. As lagoas foram divididas em faixas, cada uma delas representando um tratamento. As faixas das lagoas receberam uma aplicação inicial de fluridone, procurando-se atingir a concentração de 20 ppb. As aplicações subseqüentes foram dimensionadas para recompor e/ou manter esta concentração, sendo realizadas sempre com o auxílio de uma barra de aplicação munida de três mangueiras, com pontas injetoras submersas na água, em três profundidades (0,2, 0,6 e 1,2 m. O volume de aplicação foi mantido próximo a 54 l ha-1 de calda. Foram feitas avaliações visuais dos sintomas de fitointoxicação nas três espécies estudadas, assim como avaliação da biomassa. Nas condições da pesquisa, o fluridone controlou as macrófitas submersas Egeria najas e Egeria densa; quando cessou o efeito do fluridone, aconteceu a reinfestação de Egeria densa e Egeria najas; e não houve controle de Ceratophyllum demersum nem das espécies não-alvo, como Salvinia auriculata, Ipomoea spp., Merremia sp., Typha latifolia e Cyperus spp.The objective of this study was to evaluate the efficacy of the herbicide fluridone on the control of submersed aquatic weeds (Egeria densa Planch., Egeria najas Planch. and Ceratophyllum demersum, the major aquatic weeds in the reservoir of Engº Souza Dias (Jupiá Hydroelecric Power Plant, Itapura, São Paulo. The experiment, consisted of fluridone applications and was carried out in bays of the Tietê River, called Flórida and Barrenta. The lakes were divided into zones, each considered a treatment. All

  1. A review of neogene and quaternary snakes of Central and Eastern Europe. Part 11: natricinae, elapidae, viperidae

    Szyndlar, Z.

    1991-08-01

    Full Text Available Remains of Neogene and Quaternary "natricine" colubrids, elapids and viperids, including snakes previously described and those undescribed yet, coming from Poland, Ukraine, Moldavia, Czechoslovakia, Austria, Hungary, Romania, Bulgaria, and Greece are discussed. The following taxa, including 11 extinct species, were recognized: "Natricinae": Neonatrix nova, Neonatrix sp., Palaeonatrix silesiaca, Palaeonatrix lehmani, Natrix longivertebrata, Natrix cf. N. longivertebrata, Natrix natrix, Natrix tesselata, Natrix cf. N. tesselata, Natrix sp., "Natricinae" indet.; Elapidae: Naja romani, Naja sp., cf. Naja sp.; Viperidae: Vipera platyspondyla, Vipera sarmatica, Vipera burgenlandica, Vipera gedulyi, Vipera kuchurganica, Vipera antiqua, Vipera cf. V. ammodytes, Vipera berus, Vipera sp ('Oriental vipers' group, Vipera sp. ('aspis' group, Vipera sp. ('berus' group, Vipera sp. . (status unknown. Taxonomic status of two other extinct species, Natrix parva and Laophis crotaloides, is uncertain. Modern species appeared fírst in Central and East Europe in the middle Pliocene (MN 15. Older snakes belonged to extinct species of either extinct or extant genera; taxonomic distinction of most extinct genera is, however, not fully demonstrated. Best recognized oldest snakes from the area (Elapidae, Viperidae, and sorne Colubridae are clearly referable to modern genera and intrageneric subdivisions occurring today are observed in oldest (Iower Miocene remains; closest living relatives of these fossils are presently distributed in the Oriental Realm.Se revisan y estudian los restos neógenos y cuaternarios de colúbridos «natricinos», elápidos y vipéridos, incluyendo tanto serpientes previamente descritas como- otras inéditas. Los materiales analizados proceden de Polonia, Ukrania, Moldavia, Checoslovaquia, Austria, Hungría, Rumania, Bulgaria y Grecia. Se reconocen los siguientes taxones, incluyendo 11 especies extinguidas: Natricinae: Neonatrix nova

  2. Eficiência de fluridone no controle de plantas aquáticas submersas e efeitos sobre algumas características ambientais Fluridone efficacy in controling submersed aquatic weeds and its effects on some environmental characteristics

    D.A.S. Marcondes

    2002-01-01

    Full Text Available O objetivo deste estudo foi avaliar a eficiência do herbicida fluridone no controle de plantas aquáticas submersas (Egeria densa, Egeria najas e Ceratophyllum demersum, assim como seus efeitos sobre algumas características ambientais. A pesquisa foi conduzida no reservatório da Usina Hidrelétrica Eng. Souza Dias (Jupiá, região noroeste do Estado de São Paulo, em uma reentrância denominada lagoa Vírgula. A lagoa foi dividida em nove faixas e seis delas receberam uma aplicação inicial de fluridone para se obter uma concentração de 20 ppb. As aplicações subseqüentes foram dimensionadas para recompor esta concentração. Para o estudo do carreamento do herbicida pelo fluxo de água, foi efetuado o monitoramento das suas concentrações nas nove faixas da lagoa (com e sem aplicação e em áreas a jusante e a montante. Foram analisados os efeitos do fluridone sobre características ambientais como: turbidez, temperatura da água, condutividade elétrica, concentração de oxigênio, pH e resíduos de fluridone. A eficácia do controle foi avaliada visualmente (pelos sintomas de fitointoxicação nas três espécies estudadas e pela amostragem de biomassa. Observou-se que o fluridone controlou de forma satisfatória E. najas e E. densa. Quando cessou o efeito do fluridone, aconteceu a reinfestação de E. densa e E. najas. Não houve controle de C. demersum. O fluridone não produziu efeitos adversos sobre as características de qualidade ambiental estudadas.This study aimed to evaluate the efficacy of the herbicide fluridone to control submersed aquatic weeds (Egeria densa, Egeria najas and Ceratophyllum demersum, as well as its effects on some environmental characteristics. The research was carried out in the reservoir of Eng. Souza Dias (Jupiá Hydro-elecric plant power, Station in northwestern São Paulo, Brazil, in Lagoa Vírgula bay. The bay was divided in nine zones and six of them received an initial application of fluridone

  3. Avaliação de herbicidas para o controle de egéria em laboratório, caixa d'água e represa sem fluxo de água Efficacy of fluridone in controlling Egeria spp. in tanks and in a small pond without water flow

    R.H. Tanaka

    2002-01-01

    Full Text Available Este projeto teve por objetivo avaliar a eficácia de herbicidas para controle de plantas aquáticas submersas das espécies Egeria densa e Egeria najas. O estudo foi realizado em três etapas consecutivas: em laboratório, em caixas d'água e numa represa de pequeno porte, sem fluxo de água. Na primeira etapa, avaliou-se a eficiência de 23 herbicidas utilizados em áreas agrícolas e disponíveis no mercado brasileiro. As elevadas concentrações em que os herbicidas foram efetivos inviabilizam programas de controle fundamentados em uma única aplicação. No experimento em caixas d'água, foram avaliados os efeitos de doses crescentes de fluridone, nas formulações líquida e granulada, no controle de Egeria densa e Egeria najas. Foram testadas as concentrações de 10, 20, 40, 80 e 150 ppb de fluridone na formulação líquida e 20, 40, 80 e 150 ppb na granulada. Após uma única aplicação, os resultados indicaram que o fluridone, nas concentrações de 80 e 150 ppb, em ambas as formulações, foi eficaz no controle dessas duas espécies. No experimento em represa de pequeno porte sem fluxo de água, avaliou-se o efeito da manutenção das concentrações de fluridone no controle de Egeria najas. Uma represa de 1.980 m² foi tratada com sete aplicações de fluridone, na formulação líquida, visando a manutenção das concentrações do ingrediente ativo na água entre 10 e 20 ppb. Os resultados indicaram que o controle proporcionado pelo herbicida foi superior a 99%. Não houve modificação significativa nas características relacionadas à qualidade da água.The objective of this research was to evaluate the efficacy of herbicides in controlling the submerged aquatic weeds Egeria densa and Egeria najas. The study was carried out in three consecutive stages: in the laboratory, in tanks and in a small pond without water flow. In the first stage, the efficacy of 23 herbicides used in agriculture and available in Brazil was evaluated

  4. Enzymatic hydrolysis of short-chain lecithin/long-chain phospholipid unilamellar vesicles: sensitivity of phospholipases to matrix phase state.

    Gabriel, N E; Agman, N V; Roberts, M F

    1987-11-17

    Short-chain lecithin/long-chain phospholipid unilamellar vesicles (SLUVs), unlike pure long-chain lecithin vesicles, are excellent substrates for water-soluble phospholipases. Hemolysis assays show that greater than 99.5% of the short-chain lecithin is partitioned in the bilayer. In these binary component vesicles, the short-chain species is the preferred substrate, while the long-chain phospholipid can be treated as an inhibitor (phospholipase C) or poor substrate (phospholipase A2). For phospholipase C Bacillus cereus, apparent Km and Vmax values show that bilayer-solubilized diheptanoylphosphatidylcholine (diheptanoyl-PC) is nearly as good a substrate as pure micellar diheptanoyl-PC, although the extent of short-chain lecithin hydrolysis depends on the phase state of the long-chain lipid. For phospholipase A2 Naja naja naja, both Km and Vmax values show a greater range: in a gel-state matrix, diheptanoyl-PC is hydrolyzed with micellelike kinetic parameters; in a liquid-crystalline matrix, the short-chain lecithin becomes comparable to the long-chain component. Both enzymes also show an anomalous increase in specific activity toward diheptanoyl-PC around the phase transition temperature of the long-chain phospholipid. Since the short-chain lecithin does not exhibit a phase transition, this must reflect fluctuations in head-group area or vertical motions of the short-chain lecithin caused by surrounding long-chain lecithin molecules. These results are discussed in terms of a specific model for SLUV hydrolysis and a general explanation for the "interfacial activation" observed with water-soluble phospholipases.

  5. Macrophytes of the Grlište reservoir (Serbia: Fifteen years after its establishment

    Stanković Ž.

    2009-01-01

    Full Text Available A large number of macrophytes, often in dense populations, have developed on the Grlište Reservoir, Serbia over a period of 15 years. Fast development of vegetation is a consequence of anthropogenic impact in lake management. The methodology used in this research covered 100% of the water body, including all areas with or without aquatic plants. The results indicate that plant communities are still in the early phase of development. This leaves space for future development of competitor macrophyte species (Najas marina, Eleocharis palustris, Typha latifolia, Typha angustifolia, Phragmites australis, etc. capable of endangering stability of the lake, which will tend toward eutrophication.

  6. Discovery Of Human Antibodies Against Spitting Cobra Toxins

    Bojsen-Møller, Laura; Lohse, Brian; Harrison, Robert

    Current snakebite envenoming treatment options consist of animal-derived antisera and are associated with severe adverse reactions due to the heterologous nature of the animal-derived antibodies present in these antisera, and the presence of therapeutically irrelevant antibodies. The African...... spitting cobras are among the most medically important snakes in sub-Saharan regions due to the severity of the clinical outcomes caused by their cytotoxic venom, which is derived from cytotoxins of the 3FTx toxin family and PLA2. Here we report the results of our progress in identifying human antibodies...... targeting relevant toxins from the venom of the black necked spitting cobra (Naja nigricolis)....

  7. A comparative study on the distribution of non-specific esterase amongst the various constituents of retinas of some vertebrates.

    Tyagi, H R; Tewari, H B

    1979-01-01

    A wide coverage of the retinae of a large number of animals (Calotes, Varanus, Naja, Athene, Passer, Streptopelia, Psittacula and Funambulus) from the point of view of the histoenzymological distribution of non-specific esterase amongst the various constituents reveals mostly identical patterns. They are as follows: 1. Outer segments - positive in all cases. 2. Outer plexiform layer - equipped with enzymatic activity in all the instances. 3. Inner nuclear layer - thin cytoplasmic rim of the neurons characterized by positive activity; the nuclei of the neurons are completely negative. 4. Inner plexiform layer - this layer is endowed with the enzymatic activity. 5. Ganglion cells - negative in all cases. 6. Nerve fibres of the layer of nerve fibres, situated adjasent to ganglion cells are positive in all the animals; in case of squirrel oligodandroglial cells present in the region have demonstrated activity of a high order. On of the high-lights of the present contribution is demarcation of the inner plexiform layer into three stratified zones, equipped with enzymatic activity in Calotes, Streptopelia, Naja and Funambulus. Such stratifications are not seen in Varanus, Passer and Psittacula. The significance of the various patterns and the equipment of the enzyme in various constituents at various locals have been discussed in relation to the metabolic functions, zone-wise and interzone-wise in visual processes of various animals.

  8. A Turn-on Fluorescence Sensor for Heparin Detection Based on a Release of Taiwan Cobra Cardiotoxin from a DNA Aptamer or Adenosine-Based Molecular Beacon.

    Shi, Yi-Jun; Wang, Liang-Jun; Lee, Yuan-Chin; Huang, Chia-Hui; Hu, Wan-Ping; Chang, Long-Sen

    2018-02-19

    This study presents two sensitive fluorescent assays for sensing heparin on the basis of the electrostatic interaction between heparin and Naja naja atra cardiotoxin 3 (CTX3). Owing to CTX3-induced folded structure of an adenosine-based molecular beacon (MB) or a DNA aptamer against CTX3, a reduction in the fluorescent signal of the aptamer or MB 5'-end labeled with carboxyfluorescein (FAM) and 3'-end labeled with 4-([4-(dimethylamino)phenyl]azo)-benzoic acid (DABCYL) was observed upon the addition of CTX3. The presence of heparin and formation of the CTX3-heparin complex caused CTX3 detachment from the MB or aptamer, and restoration of FAM fluorescence of the 5'-FAM-and-3'-DABCYL-labeled MB and aptamer was subsequently noted. Moreover, the detection of heparin with these CTX3-aptamer and CTX3-MB sensors showed high sensitivity and selectivity toward heparin over chondroitin sulfate and hyaluronic acid regardless of the presence of plasma. The limit of detection for heparin in plasma was determined to be 16 ng/mL and 15 ng/mL, respectively, at a signal-to-noise ratio of 3. This study validates the practical utility of the CTX3-aptamer and CTX3-MB systems for determining the concentration of heparin in a biological matrix.

  9. The Crystal Structure of Cobra Venom Factor, a Cofactor for C3- and C5-Convertase CVFBb

    Krishnan, Vengadesan; Ponnuraj, Karthe; Xu, Yuanyuan; Macon, Kevin; Volanakis, John E.; Narayana, Sthanam V.L.; (Madras); (UAB)

    2009-05-26

    Cobra venom factor (CVF) is a functional analog of human complement component C3b, the active fragment of C3. Similar to C3b, in human and mammalian serum, CVF binds factor B, which is then cleaved by factor D, giving rise to the CVFBb complex that targets the same scissile bond in C3 as the authentic complement convertases C4bC2a and C3bBb. Unlike the latter, CVFBb is a stable complex and an efficient C5 convertase. We solved the crystal structure of CVF, isolated from Naja naja kouthia venom, at 2.6 {angstrom} resolution. The CVF crystal structure, an intermediate between C3b and C3c, lacks the TED domain and has the CUB domain in an identical position to that seen in C3b. The similarly positioned CUB and slightly displaced C345c domains of CVF could play a vital role in the formation of C3 convertases by providing important primary binding sites for factor B.

  10. Syndromic approach to treatment of snake bite in Sri Lanka based on results of a prospective national hospital-based survey of patients envenomed by identified snakes.

    Ariaratnam, Christeine A; Sheriff, Mohamed H Rezvi; Arambepola, Carukshi; Theakston, R David G; Warrell, David A

    2009-10-01

    Of 860 snakes brought to 10 hospitals in Sri Lanka with the patients they had bitten, 762 (89%) were venomous. Russell's vipers (Daboia russelii) and hump-nosed pit vipers (Hypnale hypnale) were the most numerous and H. hypnale was the most widely distributed. Fifty-one (6%) were misidentified by hospital staff, causing inappropriate antivenom treatment of 13 patients. Distinctive clinical syndromes were identified to aid species diagnosis in most cases of snake bite in Sri Lanka where the biting species is unknown. Diagnostic sensitivities and specificities of these syndromes for envenoming were 78% and 96% by Naja naja, 66% and 100% by Bungarus caeruleus, 14% and 100% by Daboia russelii, and 10% and 97% by Hypnale hypnale, respectively. Although only polyspecific antivenoms are used in Sri Lanka, species diagnosis remains important to anticipate life-threatening complications such as local necrosis, hemorrhage and renal and respiratory failure and to identify likely victims of envenoming by H. hypnale who will not benefit from existing antivenoms. The technique of hospital-based collection, labeling and preservation of dead snakes brought by bitten patients is recommended for rapid assessment of a country's medically-important herpetofauna.

  11. Activity evaluation from different native or irradiated with {sup 60} Co gamma rays snake venoms and their inhibitory effect on Leishmania (Leishmania) amazonensis; Avaliacao da atividade de diferentes venenos de serpentes, nativos ou irradiados, com radiacao gama de {sup 60} Co, quanto ao poder inibitorio do crescimento de Leishmania (Leishmania) amazonensis

    Lourenco, Cecilia de Oliveira

    2000-07-01

    Cutaneous leishmaniasis is a disease, caused by Leishmania parasites, that occurs frequently in tropical and sub-tropical regions of the world. Skin lesions that could results in disfiguring aspect characterize it. The treatment is based on few drugs as antimony salts or pentamidine that are toxic with increasing resistance by the parasite. Alternative forms of disease treatment are in constant search, including natural components as snake venoms. Previous studies demonstrate that some components of snake venoms have an inhibitory effect against those parasites, including Leishmania species. Although snake venoms presented high toxicity, several methods have been described to detoxify most or some of their toxic components, with favorable results by the use of gamma irradiation. In this report we tested several native and irradiated snake venoms for inhibitory effect against Leishmania (Leishmania) amazonensis parasite and LLCMK{sub 2} mammalian cells, with enzymatic tests and electrophoresis. There are significant activity in Acanthophis antarcticus, Agkistrodon bilineatus, Bothrops moojeni, Bothrops jararaca, Hoplocephalus stephensi, Naja melanoleuca, Naja mossambica, Pseudechis australis, Pseudechis colletti, Pseudechis guttatus and Pseudechis porphyriacus, venom being inactive Pseudonaja textilis, Notechis ater niger, Notechis scutatus. Oxyuranus microlepidotus and Oxyuranus scutellatus venoms. After 2 KGy of {sup 60}Co irradiation most venom loses significantly their activity. Venoms with antileishmanial activity presented L-amino acid oxidase (L-AO) activity and showed common protein with a molecular weight about 60kDa in SDS-PAGE. These results indicate that L-AO activity in those venoms are probably related with antileishmanial effect. (author)

  12. Computational and in vitro insights on snake venom phospholipase A2 inhibitor of phytocompound ikshusterol3-O-glucoside of Clematis gouriana Roxb. ex DC.

    Muthusamy, Karthikeyan; Chinnasamy, Sathishkumar; Nagarajan, Subbiah; Sivaraman, Thirunavukkarasu

    2017-12-14

    Ikshusterol3-O-glucoside was isolated from Clematis gouriana Roxb. ex DC. root. A structure of the isolated compound was determined on the basis of various spectroscopic interpretations (UV, NMR, FTIR, and GC-MS-EI). This structure was submitted in the PubChem compound database (SID 249494133). SID 249494133 was carried out by density functional theory calculation to observe the chemical stability and electrostatic potential of this compound. The absorption, distribution, metabolism, and excretion property of this compound was predicted to evaluate the drug likeness and toxicity. In addition, molecular docking, quantum polarized ligand docking, prime MMGBSA calculation, and induced fit docking were performed to predict the binding status of SID 249494133 with the active site of phospholipase A 2 (PLA 2 ) (PDB ID: 1A3D). The stability of the compound in the active site of PLA 2 was carried out using molecular dynamics simulation. Further, the anti-venom activity of the compound was assessed using the PLA 2 assay against Naja naja (Indian cobra) crude venom. The results strongly show that Ikshusterol3-O-glucoside has a potent snake-venom neutralizing capacity and it might be a potential molecule for the therapeutic treatment for snakebites.

  13. In Vitro and In Vivo Evaluation of Polyherbal Formulation against Russell's Viper and Cobra Venom and Screening of Bioactive Components by Docking Studies

    Sakthivel, G.; Dey, Amitabha; Nongalleima, Kh.; Chavali, Murthy; Rimal Isaac, R. S.; Singh, N. Surjit; Deb, Lokesh

    2013-01-01

    The present study emphasizes to reveal the antivenom activity of Aristolochia bracteolata Lam., Tylophora indica (Burm.f.) Merrill, and Leucas aspera S. which were evaluated against venoms of Daboia russelli russelli (Russell's viper) and Naja naja (Indian cobra). The aqueous extracts of leaves and roots of the above-mentioned plants and their polyherbal (1 : 1 : 1) formulation at a dose of 200 mg/kg showed protection against envenomed mice with LD50 doses of 0.44 mg/kg and 0.28 mg/kg against Russell's viper and cobra venom, respectively. In in vitro antioxidant activities sample extracts showed free radical scavenging effects in dose dependent manner. Computational drug design and docking studies were carried out to predict the neutralizing principles of type I phospholipase A2 (PLA2) from Indian common krait venom. This confirmed that aristolochic acid and leucasin can neutralize type I PLA2 enzyme. Results suggest that these plants could serve as a source of natural antioxidants and common antidote for snake bite. However, further studies are needed to identify the lead molecule responsible for antidote activity. PMID:23533518

  14. Activity evaluation from different native or irradiated with 60 Co gamma rays snake venoms and their inhibitory effect on Leishmania (Leishmania) amazonensis

    Lourenco, Cecilia de Oliveira

    2000-01-01

    Cutaneous leishmaniasis is a disease, caused by Leishmania parasites, that occurs frequently in tropical and sub-tropical regions of the world. Skin lesions that could results in disfiguring aspect characterize it. The treatment is based on few drugs as antimony salts or pentamidine that are toxic with increasing resistance by the parasite. Alternative forms of disease treatment are in constant search, including natural components as snake venoms. Previous studies demonstrate that some components of snake venoms have an inhibitory effect against those parasites, including Leishmania species. Although snake venoms presented high toxicity, several methods have been described to detoxify most or some of their toxic components, with favorable results by the use of gamma irradiation. In this report we tested several native and irradiated snake venoms for inhibitory effect against Leishmania (Leishmania) amazonensis parasite and LLCMK 2 mammalian cells, with enzymatic tests and electrophoresis. There are significant activity in Acanthophis antarcticus, Agkistrodon bilineatus, Bothrops moojeni, Bothrops jararaca, Hoplocephalus stephensi, Naja melanoleuca, Naja mossambica, Pseudechis australis, Pseudechis colletti, Pseudechis guttatus and Pseudechis porphyriacus, venom being inactive Pseudonaja textilis, Notechis ater niger, Notechis scutatus. Oxyuranus microlepidotus and Oxyuranus scutellatus venoms. After 2 KGy of 60 Co irradiation most venom loses significantly their activity. Venoms with antileishmanial activity presented L-amino acid oxidase (L-AO) activity and showed common protein with a molecular weight about 60kDa in SDS-PAGE. These results indicate that L-AO activity in those venoms are probably related with antileishmanial effect. (author)

  15. Prevalence of Amblyomma gervaisi ticks on captive snakes in Tamil Nadu.

    Catherine, B R; Jayathangaraj, M G; Soundararajan, C; Bala Guru, C; Yogaraj, D

    2017-12-01

    Ticks are the important ectoparasites that occur on snakes and transmit rickettsiosis, anaplasmosis and ehrlichiosis. A total of 62 snakes (Reticulated python, Indian Rock Python, Rat snakes and Spectacled cobra) were examined for tick infestation at Chennai Snake Park Trust (Guindy), Arignar Anna Zoological Park (Vandalur) and Rescue centre (Velachery) in Tamil Nadu from September, 2015 to June, 2016. Ticks from infested snakes were collected and were identified as Amblyomma gervaisi (previously known as Aponomma gervaisi ). Overall occurrence of tick infestation on snakes was 66.13%. Highest prevalence of tick infestation was observed more on Reticulated Python ( Python reticulatus , 90.91%) followed by Indian Rock Python ( Python molurus , 88.89%), Spectacled cobra ( Naja naja, 33.33%) and Rat snake ( Ptyas mucosa, 21.05%). Highest prevalence of ticks were observed on snakes reared at Chennai Snake Park Trust, Guindy (83.33%), followed by Arignar Anna Zoological Park, Vandalur (60.00%) and low level prevalence of 37.50% on snakes at Rescue centre, Velachery. Among the system of management, the prevalence of ticks were more on captive snakes (70.37%) than the free ranging snakes (37.5%). The presences of ticks were more on the first quarter when compared to other three quarters and were highly significant ( P  ≤ 0.01).

  16. Tick infestation on wild snakes in northern part of western Ghats of India.

    Pandit, Pranav; Bandivdekar, Ruta; Geevarghese, G; Pande, Satish; Mandke, Omkar

    2011-05-01

    In total, 167 individuals of 30 species of snakes belonging to 22 genera and five families were examined for tick infestation from November 2008 to March 2010. Only two species of snakes, Ptyas mucosa (L., 1758) (Indian rat snake) and Naja naja (L., 1758) (spectacled cobra), were found infested by ticks. All ticks collected were identified to be Amblyomma gervaisi [previously Aponomma gervaisi (Lucas, 1847) 1. The average prevalence of these ticks on Indian rat snakes (n=48) was 29.16%, with abundance of 7.02 ticks per individual; on spectacled cobras (n=20), average prevalence was 30.00%, with abundance of 6.9 ticks per individual. The nymphs and males were predominant. All the ticks were found on the dorsal aspect of the body of the snake, and no ticks were recorded on the head, tail, or ventral body. The rate of tick infestation was highest in scrubland and was lowest in evergreen forests. Female Indian rat snakes showed higher tick infestation rates than male Indian rat snakes. Using Mann-Whitney U test, we found that longer snakes of both species had significantly higher rate of tick infestation in both the species of snakes.

  17. Lactadherin inhibits secretory phospholipase A2 activity on pre-apoptotic leukemia cells.

    Steffen Nyegaard

    Full Text Available Secretory phospholipase A2 (sPLA2 is a critical component of insect and snake venoms and is secreted by mammalian leukocytes during inflammation. Elevated secretory PLA2 concentrations are associated with autoimmune diseases and septic shock. Many sPLA2's do not bind to plasma membranes of quiescent cells but bind and digest phospholipids on the membranes of stimulated or apoptotic cells. The capacity of these phospholipases to digest membranes of stimulated or apoptotic cells correlates to the exposure of phosphatidylserine. In the present study, the ability of the phosphatidyl-L-serine-binding protein, lactadherin to inhibit phospholipase enzyme activity has been assessed. Inhibition of human secretory phospholipase A2-V on phospholipid vesicles exceeded 90%, whereas inhibition of Naja mossambica sPLA2 plateaued at 50-60%. Lactadherin inhibited 45% of activity of Naja mossambica sPLA2 and >70% of human secretory phospholipase A2-V on the membranes of human NB4 leukemia cells treated with calcium ionophore A23187. The data indicate that lactadherin may decrease inflammation by inhibiting sPLA2.

  18. Parasitic fauna of captive snakes in Tamilnadu, India

    Nakulan Valsala Rajesh

    2015-07-01

    Full Text Available Objective: To study the parasitic fauna on serpentines under captive condition in zoological park of Tamilnadu, India. Methods: Fecal samples were collected from (n = 247 serpentines, Arignar Anna Zoological Park (n = 22, Vandalur, Tamilnadu, India and Snake Park (n = 27, Guindy, Tamilnadu, India and screened for endoparasites using sedimentation techniques. Ectoparasites were also reported in this study. Results: Coprological examination (n = 247 from captive snakes (n = 49 on random analysis revealed strongyles were predominant in Arignar Anna Zoological Park, Vandalur and Snake Park, Guindy, however the parasites were absent in king cobras (Ophiophagus hannah. Eggs of Capillaria sp. showed less predominance in Vandalur and Gunidy. Rat snakes [Ptyas mucosus (P. mucosus] showed higher prevalence of strongyle infection in Vandalur, and Russell’s viper (Daboia russelii showed higher prevalence in Guindy. Study on ectoparasites revealed Aponomma gerviasii ticks in P. mucosus, Indian cobras (Naja naja, king cobras (Ophiophagus hannah, reticulated pythons (Python reticulates and Indian rock pythons (Python molurus, among them, the most heavy infestation was documented in P. mucosus (n = 9. Conclusions: Confinement favour stress and dysecdysis in captive condition affect the health status of snakes in zoological park.

  19. Phospholipase a properties of several snake venom preparations.

    Nutter, L J; Privett, O S

    1966-07-01

    The hydrolytic properties of the venoms of seven species of snakes,Crotalus adamanteus, Ancistrodon contortrix, Naja naja, Bothrops atrox, Ophiophagus hannah, Crotalus atrox andVipera russeli, were studied with purified lecithins and mixtures of lecithins of known fatty acid and class composition as substrates.The relative rates of hydrolysis of the fatty acids by the above venoms were studied by analysis of the products of the reaction at intervals during the course of the reaction. Of the seven venoms studied, that ofOphiophagus hannah was the only one which did not give some degree of preferential rate of hydrolysis of individual fatty acids.In general, saturated fatty acids were liberated faster than unsaturated fatty acids; differences in the rates of the hydrolysis of individual saturate and unsaturated fatty acids were also observed. Individual classes of lecithin were also hydrolyzed at different rates. For the determination of the distribution of the fatty acids between the alpha- and beta-position of lecithin, the reaction should be carried to completion. If the reaction requires a prolonged time to go to completion, it should be carried out under nitrogen to prevent autoxidation.

  20. Ethnozoological study of traditional medicinal appreciation of animals and their products among the indigenous people of Metema Woreda, North-Western Ethiopia.

    Kendie, Fasil Adugna; Mekuriaw, Sileshi Andualem; Dagnew, Melkamu Andargie

    2018-05-23

    Using animals for different purposes goes back to the dawn of mankind. Animals served as a source of food, medicine, and clothing for humans and provided other services. This study was designed to undertake a cross-sectional ethnozoological field survey among the residents of Metema Woreda from November 2015 to May 2016. Data were collected through studied questionnaires, interviews, and focus group discussions with 36 purposively selected respondents. Ethnozoological data were collected of the local name of the animals, part of the animal used, mode of preparation and administration, and of additional information deemed useful. A total of 51 animal species were identified to treat around 36 different ailments. Of the animals used therapeutically, 27 species were mammals, 9 were birds, 7 arthropods, 6 reptiles, and 1 species each represented fish and annelids. Furthermore, the honey of the bee Apis mellifera was used to relieve many ailments and scored the highest fidelity value (n = 35.97%). The snake (Naja naja) and the teeth of crocodiles (Crocodylus spp.) had the lowest fidelity value (n = 2.56%). The results show that there is a wealth of ethnozoological knowledge to be documented which could be of use in developing new drugs. Hence, it is hoped that the information contained in this paper will be useful in future ethnozoological, ethnopharmacological, and conservation-related research of the region.

  1. Cardiotoxin III Inhibits Proliferation and Migration of Oral Cancer Cells through MAPK and MMP Signaling

    Ching-Yu Yen

    2013-01-01

    Full Text Available Cardiotoxin III (CTXIII, isolated from the snake venom of Formosan cobra Naja naja atra, has previously been found to induce apoptosis in many types of cancer. Early metastasis is typical for the progression of oral cancer. To modulate the cell migration behavior of oral cancer is one of the oral cancer therapies. In this study, the possible modulating effect of CTXIII on oral cancer migration is addressed. In the example of oral squamous carcinoma Ca9-22 cells, the cell viability was decreased by CTXIII treatment in a dose-responsive manner. In wound-healing assay, the cell migration of Ca9-22 cells was attenuated by CTXIII in a dose- and time-responsive manner. After CTXIII treatment, the MMP-2 and MMP-9 protein expressions were downregulated, and the phosphorylation of JNK and p38-MAPK was increased independent of ERK phosphorylation. In conclusion, CTXIII has antiproliferative and -migrating effects on oral cancer cells involving the p38-MAPK and MMP-2/-9 pathways.

  2. Use of immunoturbidimetry to detect venom-antivenom binding using snake venoms.

    O'Leary, M A; Maduwage, K; Isbister, G K

    2013-01-01

    Immunoturbidimetry studies the phenomenon of immunoprecipitation of antigens and antibodies in solution, where there is the formation of large, polymeric insoluble immunocomplexes that increase the turbidity of the solution. We used immunoturbidimetry to investigate the interaction between commercial snake antivenoms and snake venoms, as well as cross-reactivity between different snake venoms. Serial dilutions of commercial snake antivenoms (100μl) in water were placed in the wells of a microtitre plate and 100μl of a venom solution (50μg/ml in water) was added. Absorbance readings were taken at 340nm every minute on a BioTek ELx808 plate reader at 37°C. Limits imposed were a 30minute cut-off and 0.004 as the lowest significant maximum increase. Reactions with rabbit antibodies were carried out similarly, except that antibody dilutions were in PBS. Mixing venom and antivenom/antibodies resulted in an immediate increase in turbidity, which either reached a maximum or continued to increase until a 30minute cut-off. There was a peak in absorbance readings for most Australian snake venoms mixed with the corresponding commercial antivenom, except for Pseudonaja textilis venom and brown snake antivenom. There was cross-reactivity between Naja naja venom from Sri Lanka and tiger snake antivenom indicated by turbidity when they were mixed. Mixing rabbit anti-snake antibodies with snake venoms resulted in increasing turbidity, but there was not a peak suggesting the antibodies were not sufficiently concentrated. The absorbance reading at pre-determined concentrations of rabbit antibodies mixed with different venoms was able to quantify the cross-reactivity between venoms. Indian antivenoms from two manufacturers were tested against four Sri Lankan snake venoms (Daboia russelli, N. naja, Echis carinatus and Bungarus caeruleus) and showed limited formation of immunocomplexes with antivenom from one manufacturer. The turbidity test provides an easy and rapid way to compare

  3. Maintaining the competitiveness of the American fisheries society journals: an assessment based on influence and cost-effectiveness

    Hewitt, David A.; Link, Jason S.; Steinich, Dave R.; Wahl, David H.; Mather, Martha E.

    2009-01-01

    Recent changes in the landscape of scientific publishing prompted the Publications Overview Committee of the American Fisheries Society (AFS) to review the Society's portfolio of scientific journals. We evaluated journals based on metrics in two categories: (1) citation-based measures of the influence of a journal on the scientific literature, and (2) measures of the cost-effectiveness of a journal (citation rate adjusted for subscription cost). Over the long-term, we found that ecology journals had far stronger citation-based influence than fisheries and aquatic sciences journals, and that journals publishing primarily basic research had stronger influence than journals publishing applied research (including four AFS journals and Fisheries magazine). In evaluating the current status of fisheries and aquatic sciences journals, we found that metrics of influence and cost-effectiveness provided considerably different portrayals of journals relative to their peers. In terms of citation-based influence, we found that the AFS journal Transactions of the American Fisheries Society (TAFS) and Fisheries magazine were competitive with highly regarded peer fisheries journals, but that North American Journal of Aquaculture (NAJA) and Journal of Aquatic Animal Health (JAAH) were less influential than their peers. The citation-based influence of North American Journal of Fisheries Management (NAJFM) was intermediate between TAFS/Fisheries and NAJA/JAAH. For journals like NAJFM and NAJA, we expect that much of the scientific influence on policy and management is not captured by citations in the primary literature, and alternative methods of evaluation may be needed. All of the AFS journals ranked highly with regard to cost-effectiveness because their subscription costs are low, and these rankings are in accordance with membership needs and the strategic mission of AFS to provide broad and timely dissemination of scientific information. We conclude by suggesting

  4. High-throughput immuno-profiling of mamba (Dendroaspis) venom toxin epitopes using high-density peptide microarrays

    Engmark, Mikael; Andersen, Mikael Rørdam; Laustsen, Andreas Hougaard

    2016-01-01

    Snakebite envenoming is a serious condition requiring medical attention and administration of antivenom. Current antivenoms are antibody preparations obtained from the plasma of animals immunised with whole venom(s) and contain antibodies against snake venom toxins, but also against other antigens....... In order to better understand the molecular interactions between antivenom antibodies and epitopes on snake venom toxins, a high-throughput immuno-profiling study on all manually curated toxins from Dendroaspis species and selected African Naja species was performed based on custom-made high......-density peptide microarrays displaying linear toxin fragments. By detection of binding for three different antivenoms and performing an alanine scan, linear elements of epitopes and the positions important for binding were identified. A strong tendency of antivenom antibodies recognizing and binding to epitopes...

  5. Productividad primaria y sustancias húmicas en la ciénaga El Eneal, San Onofre Sucre-Colombia

    Elkin Libardo Ríos

    2009-01-01

    Full Text Available Entre mayo de 2003 y abril de 2004, se determinó la productividad primaria y el contenido de sustancias húmicas en la ciénaga El Eneal. En la zona pelágica se dispusieron los ensayos de medición de la productividad y se tomaron muestras de agua para el análisis de las sustancias húmicas. El sistema cenagoso del Eneal, presentó un estado oligotrófico, con una reducida producción en la época de lluvia. En contraste en época seca, cuando disminuye el nivel de agua, la producción aumentó y los niveles de oxígeno se incrementaron, debido a la presencia de la macrófita sumergida Najas guadalupensis. Esto, se asoció a la baja presencia de plancton y de nutrientes biodisponibles.

  6. Crystal structure of a snake venom cardiotoxin

    Rees, B.; Samama, J.P.; Thierry, J.C.; Gilibert, M.; Fischer, J.; Schweitz, H.; Lazdunski, M.; Moras, D.

    1987-01-01

    Cardiotoxin V/sup II/4 from Naja mossambica crystallizes in space group P6 1 (a = b = 73.9 A; c = 59.0 A) with two molecules of toxin (molecular mass = 6715 Da) in the asymmetric unit. The structure was solved by using a combination of multiple isomorphous replacement and density modification methods. Model building and least-squares refinement led to an agreement factor of 27% for a data set to 3-A resolution prior to any inclusion of solvent molecules. The topology of the molecule is similar to that found in short and long snake neurotoxins, which block the nicotinic acetylcholine receptor. Major differences occur in the conformation of the central loop, resulting in a change in the concavity of the molecule. Hydrophobic residues are clustered in two distinct areas. The existence of stable dimeric entities in the crystalline state, with the formation of a six-stranded antiparallel β sheet, may be functionally relevant

  7. [Herpetological data and management of ophidian envenomation at university hospitals in Abidjan, Côte d'Ivoire].

    Djohan, V; Menan, E I H; Yavo, W; Barro, P C K; Vanga, H; Dempah, J A; N'Dri, D K; Mignonsin, D; Akaffou, M H; Koné, K

    2010-02-01

    This study was carried in the intensive care units of Abidjan university hospitals and in the herpetology department of Pasteur Institute between January 2001 and April 2003. The purpose was to identify ophidian species that were dangerous for man and to document cases of snakebite in Abidjan. The study was carried out in two phases, i.e., collection and identification of snake species followed by review of case records involving snake envenomation at Cocody and Treichville university hospitals. A total of 5 snake families, 14 genera and 17 species including some that were dangerous for man were identified. All species except Naja nigricollis live in forest areas. Most snakebites led to simple clinical signs that regressed within 72 hours with only symptomatic treatment. However, a few cases required immunotherapy. Traditional methods of snakebite treatment were used for first line treatment in 50% of cases.

  8. Aquatic weeds: their implications in Indian nuclear industry

    Rao, T.S.; Anup Kumar, B.; Aruna Jyothi, K.; Satpathy, K.K.

    2000-01-01

    The aquatic weed infestation of KAPS cooling water system, MAPS open reservoir, and the growth of filamentous algae and bacteria in the feed water unit of HWP (Kota), was investigated. The aquatic weeds identified were: Ceratophyllum, Elodea, Hydrilla verticillata, Najas and Vallisneria species. However, at HWP (Kota) filamentous alga (Nostoc punchiformis) and bacteria (Sphaerotilus natans) were found in plenty. The metabolic products when assayed in the form of total carbohydrate content released by weeds was 3.7 mg gm -1 biomass. The metabolic products adsorb on to the resin matrix and impaired its performance at HWP (K), enhanced bacterial growth on the resin beads and furthered resin deterioration. Besides, the growth of aquatic weeds also influenced the pH of the cooling water, thereby vitiating the water treatment programme. (author)

  9. Fate of psychoactive compounds in wastewater treatment plant and the possibility of their degradation using aquatic plants.

    Mackuľak, Tomáš; Mosný, Michal; Škubák, Jaroslav; Grabic, Roman; Birošová, Lucia

    2015-03-01

    In this study we analyzed and characterized 29 psychoactive remedies, illicit drugs and their metabolites in single stages of wastewater treatment plants in the capital city of Slovakia. Psychoactive compounds were present within all stages, and tramadol was detected at a very high concentration (706 ng/L). Significant decreases of codeine, THC-COOH, cocaine and buprenorphine concentration were observed in the biological stage. Consequently, we were interested in the possibility of alternative tertiary post-treatment of effluent water with the following aquatic plants: Cabomba caroliniana, Limnophila sessiliflora, Egeria najas and Iris pseudacorus. The most effective plant for tertiary cleansing was I. pseudacorus which demonstrated the best pharmaceutical removal capacity. After 48 h codeine and citalopram was removed with 87% efficiency. After 96 h were all analyzed compounds were eliminated with efficiencies above 58%. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. The Need Of A Phenological Spectral Library Of Submersed Macrophytes For Lake Monitoring

    Wolf, Patrick; Robler, Sebastian; Schneider, Thomas; Melzer, Arnulf

    2013-12-01

    Submersed macrophytes are bio-indicators for water quality. For plant monitoring by remote sensing, in-situ reflectance measurements are necessary. Hence, systematic measurements were carried out at Lake Starnberg and Lake Tegernsee (Germany) in the year 2011. Besides two wide-spread species (Chara spp. and Potamogeton perfoliatus), the invasive species Elodea nuttallii and Najas marina were investigated. Remote sensing reflectances were calculated from downwelling irradiance and upwelling radiance. Those were collected with RAMSES spectroradiometers (320nm-950nm, 3.3nm step). As data collection took place several times, changes in the spectral responses within the growing season were detected and could be linked to population density, growing height, biomass and pigmentation. Additionally, a stable sampling method and a processing chain for the in-situ reflectance measurements were developed. Part of the processing was a water column correction, including WASI (water colour simulator). Principal component analysis showed separability of sediment from vegetation and species differentiation.

  11. Using Multispectral Sentinel-2 Data to Monitor Submerse Macrophytes

    Wolf, Patrick; Roessler, Sebastian; Schneider, Thomas; Melzer, Arnulf

    2012-04-01

    Due to climate change and the involved temperatures of Bavarian freshwater lakes, the invasive submerse macrophytes Elodea nuttallii and Najas marina exhibit a massive expansion. To map these processes, a monitoring system based on remote sensing methods is under development. The main part of the monitoring system is a coupled reflection-/growth-model, which derives biometrical parameters for the EU water framework directive (WFD) by inversion of the reflectance spectra. For operational monitoring tasks a high revisiting time is necessary. Hence, the Sentinel-2 sensor might be very promising, as filling the gap between RapidEye and WorldView2 and between hyperspectral an aerial images. This paper outlines principles, methods and first results of the project.

  12. Metal accumulation by submerged macrophytes in eutrophic lakes at the watershed scale.

    Xing, Wei; Wu, Haoping; Hao, Beibei; Liu, Guihua

    2013-10-01

    Metal concentrations (Al, Ba, Ca, K, Li, Mg, Na, Se, Sr and Ti) in submerged macrophytes and corresponding water and sediments were studied in 24 eutrophic lakes along the middle and lower reaches of the Yangtze River (China). Results showed that these eutrophic lakes have high metal concentrations in both water and sediments because of human activities. Average concentrations of Al and Na in tissues of submerged macrophytes were very high in sampled eutrophic lakes. By comparison, Ceratophyllum demersum and Najas marina accumulated more metals (e.g. Ba, Ca, K, Mg, Na, Sr and Ti). Strong positive correlations were found between metal concentrations in tissues of submerged macrophytes, probably because of co-accumulation of metals. The concentrations of Li, Mg, Na and Sr in tissues of submerged macrophytes significantly correlated with their corresponding water values, but not sediment values.

  13. AnAnalytical Study of Chinese Salt (MSG: Is it Halal or Haram (Urdu

    Dr. Junaid Akbar

    2017-01-01

    Full Text Available Monosodium Glutamate is the scientific name of Chinese salt, which also called Ajinomoto. Monosodium Glutamate was first discovered by the Japanese chemist Ikeda Kibunae in 1908. The MSG was firstly derived from seaweed. Later on MSG was got from meat, gluten,and vegetables etc. It can be derived from Najasul‘ain and GherNajasul‘ain things. If it was got from Najasul ‘ain, then there is a question about MSG that is it Halal(permissible/ lawful or Haram(non-permissible/unlawful. This research in this article is concluded that if the culture of MSG is Halal or the properIsti Halah has been done in Najas; MSG will be Halal(permissible/ lawful. However, where no such details are available about the culture of MSG, it should be avoid, although it cannot be declared Haram as per Islamic Jurisprudence rules

  14. Contribution of alginate and levan production to biofilm formation by Pseudomonas syringae

    Laue, H.; Schenk, A.; Li, H.

    2006-01-01

    formation, biofilms of Pseudomonas syringae strains with different EPS patterns were compared. The mucoid strain PG4180.muc, which produces levan and alginate, and its levan- and/or alginate-deficient derivatives all formed biofilms in the wells of microtitre plates and in flow chambers. Confocal laser...... by binding of the lectin from Naja mossambica to a fibrous structure in biofilms of all P. syringae derivatives. Production of the as yet uncharacterized additional EPS might be more important for biofilm formation than the syntheses of levan and alginate.......Exopolysaccharides (EPSs) play important roles in the attachment of bacterial cells to a surface and/or in building and maintaining the three-dimensional, complex structure of bacterial biofilms. To elucidate the spatial distribution and function of the EPSs levan and alginate during biofilm...

  15. Commented list of rare and protected vascular plants of inland water bodies of Estonia

    Helle Mäemets

    2016-10-01

    Full Text Available This presented overview of rare and protected hydrophytes, emergent plants and hygrophytes of inland water bodies of Estonia includes 60 species. In the commented list are indicated their position in the state protection categories I–III (last version in 2014, and under the Red List of Estonia (last version in 2008; marked are Natura 2000 species of the European Union. Most typical habitats for these rare species are: I. soft-water oligotrophic and semidystrophic lakes; II. mesotrophic lakes with Najas (Caulinia flexilis and Potamogeton rutilus; III. alkaline fens and wet meadows; IV. brackish or freshwater coastal lagoons; V. undamaged river stretches; VI. open shallow littoral of the largest lakes of Peipsi (Pskovsko-Chudskoe and of Võrtsjärv. Main threats of these habitats are briefly concerned, as well as the problem of conservation value of hybrids, based on the example of Sparganium species.

  16. Characterization of spent fuel assemblies for storage facilities using non destructive assay

    Lebrun, A.; Bignan, G.; Recroix, H.; Huver, M.

    1999-01-01

    Many non destructive assay (NDA) techniques have been developed by the French Atomic Energy Commission (CEA) for spent fuel characterization and management. Passive and active neutron methods as well as gamma spectrometric methods have been carried out and applied to industrial devices like PYTHON TM and NAJA. Many existing NDA methods can be successfully applied to storage, but the most promising are the neutron methods combined with on line evolution codes. For dry storage applications, active neutron measurements require further R and D to achieve accurate results. Characterization data given by NDA instruments can now be linked to automatic fuel recognition. Both information can feed the storage management software in order to meet the storage operation requirements like: fissile mass inventory, operators declaration consistency or automatic selection of proper storage conditions. (author)

  17. Photoresponsive nanocapsulation of cobra neurotoxin and enhancement of its central analgesic effects under red light

    Yang Q

    2017-05-01

    Full Text Available Qian Yang, Chuang Zhao, Jun Zhao, Yong Ye Department of Pharmaceutical Engineering, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, People’s Republic of China Abstract: Cobra neurotoxin (CNT, a peptide isolated from snake venom of Naja naja atra, shows central analgesic effects in our previous research. In order to help CNT pass through blood–brain barrier (BBB and improve its central analgesic effects, a new kind of CNT nanocapsules were prepared by double emulsification with soybean lecithin and cholesterol as the shell, and pheophorbide as the photosensitizer added to make it photoresponsive. The analgesic effects were evaluated by hot plate test and acetic acid-induced writhing in mice. The CNT nanocapsules had an average particle size of 229.55 nm, zeta potential of -53.00 mV, encapsulation efficiency of 84.81% and drug loading of 2.98%, when the pheophorbide content was 1% of lecithin weight. Pheophorbide was mainly distributed in outer layer of the CNT nanocapsules and increased the release of the CNT nanocapsules after 650 nm illumination. The central analgesic effects were improved after intraperitoneal injection of CNT at 25 and 50 µg·kg-1 under 650 nm irradiation for 30 min in the nasal cavity. Activation of pheophorbide by red light generated reactive oxygen species which opened the nanocapsules and BBB and helped the CNT enter the brain. This research provides a new drug delivery for treatment of central pain. Keywords: cobra neurotoxin, nanocapsules, photoresponsive, central analgesic effects, red light, drug delivery, photosensitizer

  18. Instability in newly-established wetlands? Trajectories of floristic change in the re-flooded Hula peatland, northern Israel

    D. Kaplan

    2012-01-01

    Full Text Available Drainage of the 6,000 ha Hula Lake and peatland in northern Israel in the late 1950s caused the loss of a very diverse and rare ecosystem and an important phytogeographic meeting zone for Holarctic and Palaeotropical species. Draining the Hula peatland was only partially successful in creating a large fertile area for cultivation, and in 1994 this led the authorities to re-flood 100 ha of the valley—the Agamon (Agmon—with the aim of rehabilitating the diverse wetland landscape, promoting ecotourism and creating a clear-water body that would contribute to the purification of Lake Kinneret. The vegetation of the restored wetland was monitored for ten years (1997–2006, recording the establishment and abundance of vascular plant species. More than 20 emergent, submerged and riparian species became established. Like a number of other shallow-water wetlands, the Agmon is characterised by considerable ecological fluctuations. This has been expressed in prominent floristic changes in the Agamon since it was created. An increased abundance of Ceratophyllum demersum and Najas minor and a decline in Potamogeton spp., Najas delilei and filamentous algae have been observed. A long-term decline in water level and sediment accumulation has brought about a significant rise in the incidence of Phragmites australis, Typha domingensis and Ludwigia stolonifera in the south-eastern area. A GIS analysis of changes in species dominance shows fluctuations over the years, with only a partial trend of succession towards a P. australis, T. domingensis and L. stolonifera community.

  19. Cloning, overexpression, and characterization of cobrotoxin

    Hsieh, H.-C.; Kumar, Thallampuranam Krishnaswamy S.; Yu Chin

    2004-01-01

    Cobrotoxin (CBTX) is a highly toxic short neurotoxin, isolated from the Taiwan cobra (Naja naja atra) venom. In the present study for the first time we report the cloning and expression of CBTX in high yields (12 mg/L) in Escherichia coli. CBTX fused to the IgG-binding domain of protein A (IgG-CBTX) was expressed in the soluble form. The misfolded CBTX portion (of the overexpressed fusion protein) was refolded under optimal redox conditions. The fusion protein (IgG-CBTX) was observed to undergo autocatalytic cleavage to yield CBTX with additional 5 amino acids upstream of its N-terminal end. The far UV and near UV circular dichroism spectra of the recombinant CBTX were identical to those of the toxin isolated from the crude venom source. Recombinant CBTX was isotope labeled ( 15 N and 13 C) and all the resonances ( 1 H, 13 C, and 15 N) in the protein have been unambiguously assigned. 1 H- 15 N HSQC spectrum of recombinant CBTX revealed that the protein is in a biologically active conformation. 1 H- 15 N chemical shift perturbation data showed that recombinant CBTX binds to a peptide derived from the α7 subunit of the Torpedo acetylcholine receptor (AchR) with high affinity. The AchR peptide is found to bind to residues located at the tip of Loop-2 in CBTX. The results of the present study provide an avenue to understand the structural basis for the high toxicity exhibited by CBTX. In addition, complete resonance assignments in CBTX (reported in this study) are expected to trigger intensive research towards the design of new pharmacological agents against certain neural disorders

  20. First molecular characterization of enteric protozoa and the human pathogenic microsporidian, Enterocytozoon bieneusi, in captive snakes in China.

    Karim, Md Robiul; Yu, Fuchang; Li, Jian; Li, Junqiang; Zhang, Longxian; Wang, Rongjun; Rume, Farzana Islam; Jian, Fuchun; Zhang, Sumei; Ning, Changshen

    2014-08-01

    Enteric protozoa are frequently found in snakes. Nevertheless, few studies regarding genetic characterization of these parasites have been carried out. We describe here the first molecular survey of protozoan pathogens from snakes in China and the first report on Enterocytozoon bieneusi genotyping in snakes in the world. Here, 240 fecal specimens were collected from two species of captive snakes, Naja naja (Indian cobra) and Ptyas mucosus (Oriental rat snake), in Guangxi Province, China, and examined by PCR amplification of the small subunit-ribosomal RNA of enteric protozoa and the internal transcribed spacer of ribosomal RNA of E. bieneusi. Cryptosporidium serpentis was identified in three specimens (2.1%) of Oriental rat snakes. Caryospora was found in 5.4% specimens, including eight from cobras (8.1%) and five from rat snakes (3.6%), and represented six new species-Caryospora sp. SKC-2014a to Caryospora sp. SKC-2014 f. Three new Eimeria species, Eimeria sp. SKE-2014a to Eimeria sp. SKE-2014c, were detected in three specimens (2.1%) from rat snakes. Additionally, Sarcocystis sp. SKS-2014 was detected in one specimen from a cobra. The infection rates of E. bieneusi were 3.0% in cobras and 5.7% in rat snakes. Sequence analysis of 11 PCR products revealed the presence of six E. bieneusi genotypes-two known genotypes (type IV and Henan V) and four new genotypes (CRep-1 to CRep-4). All six E. bieneusi genotypes belonged to the zoonotic group (group 1). This result raised the possibility that E. bieneusi could be present in animals consumed by snakes. This should be taken into consideration to better understand the diversity of the parasite, its transmission through the predator-prey relationship, and public health implications.

  1. Site-specific epsilon-NH2 monoacylation of pancreatic phospholipase A2. 2. Transformation of soluble phospholipase A2 into a highly penetrating "membrane-bound" form.

    Van der Wiele, F C; Atsma, W; Roelofsen, B; van Linde, M; Van Binsbergen, J; Radvanyi, F; Raykova, D; Slotboom, A J; De Haas, G H

    1988-03-08

    Long-chain lecithins present in bilayer structures like vesicles or membranes are only very poor substrates for pancreatic phospholipases A2. This is probably due to the fact that pancreatic phospholipases A2 cannot penetrate into the densely packed bilayer structures. To improve the weak penetrating properties of pancreatic phospholipases A2, we prepared and characterized a number of pancreatic phospholipase A2 mutants that have various long acyl chains linked covalently to Lys116 in porcine and to Lys10 in bovine phospholipase A2 [Van der Wiele, F.C., Atsma, W., Dijkman, R., Schreurs, A.M.M., Slotboom, A.J., & De Haas, G.H. (1988) Biochemistry (preceding paper in this issue)]. When monomolecular surface layers of L- and D-didecanoyllecithin were used, it was found that the introduction of caprinic, lauric, palmitic, and oleic acid at Lys116 in the porcine enzyme increases its penetrating power from 13 to about 17, 20, 32, and 22 dyn/cm, respectively, before long lag periods were obtained. Incorporation of a palmitoyl moiety at Lys10 in the bovine enzyme shifted the penetrating power from 11 to about 25 dyn/cm. Only the best penetrating mutant, viz., porcine phospholipase A2 having a palmitoyl moiety at Lys116, was able to cause complete leakage of 6-carboxyfluorescein entrapped in small unilamellar vesicles of egg lecithin under nonhydrolytic conditions. Similarly, only this latter palmitoylphospholipase A2 completely hydrolyzed all lecithin in the outer monolayer of the human erythrocyte at a rate much faster than Naja naja phospholipase A2, the most powerful penetrating snake venom enzyme presently known.

  2. A study of ribonuclease activity in venom of vietnam cobra

    Thiet Van Nguyen

    2017-09-01

    Full Text Available Abstract Background Ribonuclease (RNase is one of the few toxic proteins that are present constantly in snake venoms of all types. However, to date this RNase is still poorly studied in comparison not only with other toxic proteins of snake venom, but also with the enzymes of RNase group. The objective of this paper was to investigate some properties of RNase from venom of Vietnam cobra Naja atra. Methods Kinetic methods and gel filtration chromatography were used to investigate RNase from venom of Vietnam cobra. Results RNase from venom of Vietnam cobra Naja atra has some characteristic properties. This RNase is a thermostable enzyme and has high conformational stability. This is the only acidic enzyme of the RNase A superfamily exhibiting a high catalytic activity in the pH range of 1–4, with pHopt = 2.58 ± 0.35. Its activity is considerably reduced with increasing ionic strength of reaction mixture. Venom proteins are separated by gel filtration into four peaks with ribonucleolytic activity, which is abnormally distributed among the isoforms: only a small part of the RNase activity is present in fractions of proteins with molecular weights of 12–15 kDa and more than 30 kDa, but most of the enzyme activity is detected in fractions of polypeptides, having molecular weights of less than 9 kDa, that is unexpected. Conclusions RNase from the venom of Vietnam cobra is a unique member of RNase A superfamily according to its acidic optimum pH (pHopt = 2.58 ± 0.35 and extremely low molecular weights of its major isoforms (approximately 8.95 kDa for RNase III and 5.93 kDa for RNase IV.

  3. Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil - doi: 10.4025/actascibiolsci.v32i4.4627 Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil - doi: 10.4025/actascibiolsci.v32i4.4627

    Liliana Rodrigues

    2010-11-01

    Full Text Available Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil. This study evaluated the heterogeneity in periphytic algal community, under the influence of time colonization on artificial substratum. We also examined which abiotic variables most influenced the community in natural and artificial substratum. Egeria najas Planchon was used as natural substratum, and a plastic plant, as artificial. This experiment was carried out in a lateral arm from Rosana Reservoir, formed by Corvo Stream (Paranapanema river basin, in the period from November 21st to December 12nd, 2003, characterized as a warm and rainy period. Changes in species composition were assessed using the similarity indices. 495 taxa were registered in the phycoperiphytic community, distributed in 133 genera and 11 classes. Zygnemaphyceae, Bacillariophyceae, Chlorophyceae and Cyanophyceae presented higher species number, in both substrata. Staurodesmus, Closterium, Staurastrum and Cosmarium (Desmidiales; Gomphonema and Eunotia (Pennales; Characium, Scenedesmus and Desmodesmus (Chlorococcales; Anabaena and Aphanocapsa (Nostocales and Chroococcales, respectively were the most species-rich genera. The epiphytic community reached the highest species richness in the 15th successional day. Regardless the substratum type, the number of species was probably related to the high concentrations of nutrients (phosphorus and nitrogen.Periphytic algal community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil. This study evaluated the heterogeneity in periphytic algal community, under the influence of time colonization on artificial substratum. We also examined which abiotic variables most influenced the community in natural and artificial substratum. Egeria najas Planchon was used as natural substratum, and a plastic plant, as artificial. This experiment was

  4. Rice field flora and vegetation in the provinces of Valencia and Tarragona

    Carretero, J. L.

    1988-01-01

    Full Text Available Twenty nine emergent and twenty floating or submerged taxa , were found in the rice fields in Valencia and Tarragona provinces. Eleven of the se taxa, all them emergent, are alien Of introduced ones. Echinochloa oryzoides and E. oryzicola are the most important in both areas, together with Cyperus difformis and Echinochloa hispidula in Valencia. The remaining thirty eight taxa belong to the native flora. There are predominantly the emergent Scirpus maritimus, Alisma plantago-aquatica. Echinochloa crus-galli and Paspalum distichum; the floating Lemna minor and L. gibba; the submersed Potamogeton nodosus; Zannichellia palustris and Najas minor; and the macroscopical algae Chara vulgaris, Cladophora glomerata, Oedogonium capilliforme, Spirogyra spp., Pithophora oedogania and Hydrodictyon reticulatum. The flora evolution during the last years is analyzed and the present weed communities are studied. The contribution of the different phytosociological classes to the rice field weed flora is presented.

    De los 49 táxones registrados (29 emergentes y 20 flotantes o sumergidos 11 son exóticos introducidos, de los cuales los más importantes son Echinochloa oryzoides y E. oryzicolaen ambas zonas, además de Cyperus difformis y Echinochloa hispidula en Valencia, y el resto propios de la flora autóctona, predominando Scirpus maritimus, Alisma plantago-aquatica. Echinochloa crus-galli y Paspalum distichum como emergentes, Lemna minor y L. gibba como flotantes, Potamogeton nodosus, Zannichellia palustris y Najas minor como sumergidos y Chara vulgaris, Cladophora glomerata, Oedogonium capilliforme. Spirogyra spp., Pirhophora oedogonia e Hydrodictyon reticulatum como algas macroscópicas. Se analiza la evolución experimentada por la flora en los últimos años, además de estudiar las

  5. Nonequivalence of alpha-bungarotoxin binding sites in the native nicotinic receptor molecule

    Conti-Tronconi, B.M.; Tang, F.; Walgrave, S.; Gallagher, W.

    1990-01-01

    In the native, membrane-bound form of the nicotinic acetylcholine receptor (M-AcChR) the two sites for the cholinergic antagonist alpha-bungarotoxin (alpha-BGT) have different binding properties. One site has high affinity, and the M-AcChR/alpha-BGT complexes thus formed dissociate very slowly, similar to the complexes formed with detergent-solubilized AcChR (S-AcChR). The second site has much lower affinity (KD approximately 59 +/- 35 nM) and forms quickly reversible complexes. The nondenaturing detergent Triton X-100 is known to solubilize the AcChR in a form unable, upon binding of cholinergic ligands, to open the ion channel and to become desensitized. Solubilization of the AcChR in Triton X-100 affects the binding properties of this second site and converts it to a high-affinity, slowly reversible site. Prolonged incubation of M-AcChR at 4 degrees C converts the low-affinity site to a high-affinity site similar to those observed in the presence of Triton X-100. Although the two sites have similar properties when the AcChR is solubilized in Triton X-100, their nonequivalence can be demonstrated by the effect on alpha-BGT binding of concanavalin A, which strongly reduces the association rate of one site only. The Bmax of alpha-BGT to either Triton-solubilized AcChR or M-AcChR is not affected by the presence of concanavalin A. Occupancy of the high-affinity, slowly reversible site in M-AcChR inhibits the Triton X-100 induced conversion to irreversibility of the second site. At difference with alpha-BGT, the long alpha-neurotoxin from Naja naja siamensis venom (alpha-NTX) binds with high affinity and in a very slowly reversible fashion to two sites in the M-AcChR. We confirm here that Triton-solubilized AcChR or M-AcChR binds in a very slowly reversible fashion the same amount of alpha-NTX

  6. Identification and characterization of novel reptile cathelicidins from elapid snakes.

    Zhao, Hui; Gan, Tong-Xiang; Liu, Xiao-Dong; Jin, Yang; Lee, Wen-Hui; Shen, Ji-Hong; Zhang, Yun

    2008-10-01

    Three cDNA sequences coding for elapid cathelicidins were cloned from constructed venom gland cDNA libraries of Naja atra, Bungarus fasciatus and Ophiophagus hannah. The open reading frames of the cloned elapid cathelicidins were all composed of 576bp and coded for 191 amino acid residue protein precursors. Each of the deduced elapid cathelicidin has a 22 amino acid residue signal peptide, a conserved cathelin domain of 135 amino acid residues and a mature antimicrobial peptide of 34 amino acid residues. Unlike the highly divergent cathelicidins in mammals, the nucleotide and deduced protein sequences of the three cloned elapid cathelicidins were remarkably conserved. All the elapid mature cathelicidins were predicted to be cleaved at Valine157 by elastase. OH-CATH, the deduced mature cathelicidin from king cobra, was chemically synthesized and it showed strong antibacterial activity against various bacteria with minimal inhibitory concentration of 1-20microg/ml in the presence of 1% NaCl. Meanwhile, the synthetic peptide showed no haemolytic activity toward human red blood cells even at a high dose of 200microg/ml. Phylogenetic analysis of cathelicidins from vertebrate suggested that elapid and viperid cathelicidins were grouped together in the tree. Snake cathelicidins were evolutionary closely related to the neutrophilic granule proteins (NGPs) from mouse, rat and rabbit. Snake cathelicidins also showed a close relationship with avian fowlicidins (1-3) and chicken myeloid antimicrobial peptide 27. Elapid cathelicidins might be used as models for the development of novel therapeutic drugs.

  7. Isolation and cloning of a metalloproteinase from king cobra snake venom.

    Guo, Xiao-Xi; Zeng, Lin; Lee, Wen-Hui; Zhang, Yun; Jin, Yang

    2007-06-01

    A 50 kDa fibrinogenolytic protease, ohagin, from the venom of Ophiophagus hannah was isolated by a combination of gel filtration, ion-exchange and heparin affinity chromatography. Ohagin specifically degraded the alpha-chain of human fibrinogen and the proteolytic activity was completely abolished by EDTA, but not by PMSF, suggesting it is a metalloproteinase. It dose-dependently inhibited platelet aggregation induced by ADP, TMVA and stejnulxin. The full sequence of ohagin was deduced by cDNA cloning and confirmed by protein sequencing and peptide mass fingerprinting. The full-length cDNA sequence of ohagin encodes an open reading frame of 611 amino acids that includes signal peptide, proprotein and mature protein comprising metalloproteinase, disintegrin-like and cysteine-rich domains, suggesting it belongs to P-III class metalloproteinase. In addition, P-III class metalloproteinases from the venom glands of Naja atra, Bungarus multicinctus and Bungarus fasciatus were also cloned in this study. Sequence analysis and phylogenetic analysis indicated that metalloproteinases from elapid snake venoms form a new subgroup of P-III SVMPs.

  8. Phylogenetic relationship of Hepatozoon blood parasites found in snakes from Africa, America and Asia.

    Haklová, B; Majláthová, V; Majláth, I; Harris, D J; Petrilla, V; Litschka-Koen, T; Oros, M; Peťko, B

    2014-03-01

    The blood parasites from the genus Hepatozoon Miller, 1908 (Apicomplexa: Adeleida: Hepatozoidae) represent the most common intracellular protozoan parasites found in snakes. In the present study, we examined 209 individuals of snakes, from different zoogeographical regions (Africa, America, Asia and Europe), for the occurrence of blood parasites using both molecular and microscopic examination methods, and assess phylogenetic relationships of all Hepatozoon parasites from snakes for the first time. In total, 178 blood smears obtained from 209 individuals, representing 40 species, were examined, from which Hepatozoon unicellular parasites were found in 26 samples (14·6% prevalence). Out of 180 samples tested by molecular method polymerase chain reaction (PCR), the presence of parasites was observed in 21 individuals (prevalence 11·6%): 14 snakes from Africa belonging to six genera (Dendroaspis, Dispholidus, Mehelya, Naja, Philothamnus and Python), five snakes from Asia from the genus Morelia and two snakes from America, from two genera (Coluber and Corallus). The intensity of infection varied from one to 1433 infected cells per 10 000 erythrocytes. Results of phylogenetic analyses (Bayesian and Maximum Likelihood) revealed the existence of five haplotypes divided into four main lineages. The present data also indicate neither geographical pattern of studied Hepatozoon sp., nor congruency in the host association.

  9. Freshwater plants synthesize sulfated polysaccharides: heterogalactans from Water Hyacinth (Eicchornia crassipes).

    Dantas-Santos, Nednaldo; Gomes, Dayanne Lopes; Costa, Leandro Silva; Cordeiro, Sara Lima; Costa, Mariana Santos Santana Pereira; Trindade, Edvaldo Silva; Franco, Célia Regina Chavichiolo; Scortecci, Kátia Castanho; Leite, Edda Lisboa; Rocha, Hugo Alexandre Oliveira

    2012-01-01

    Sulfated polysaccharides (SP) are found mainly in seaweeds and animals. To date, they have only been found in six plants and all inhabit saline environments. Furthermore, there are no reports of SP in freshwater or terrestrial plants. As such, this study investigated the presence of SP in freshwaters Eichhornia crassipes, Egeria densa, Egeria naja, Cabomba caroliniana, Hydrocotyle bonariensis and Nymphaea ampla. Chemical analysis identified sulfate in N. ampla, H. bonariensis and, more specifically, E. crassipes. In addition, chemical analysis, FT-IR spectroscopy, histological analysis, scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDXA), as well as agarose gel electrophoresis detected SP in all parts of E. crassipes, primarily in the root (epidermis and vascular bundle). Galactose, glucose and arabinose are the main monosaccharides found in the sulfated polysaccharides from E. crassipes. In activated partial thromboplastin time (APTT) test, to evaluate the intrinsic coagulation pathway, SP from the root and rhizome prolonged the coagulation time to double the baseline value, with 0.1 mg/mL and 0.15 mg/mL, respectively. However, SP from the leaf and petiole showed no anticoagulant activity. Eichornia SP demonstrated promising anticoagulant potential and have been selected for further studies on bioguided fractionation; isolation and characterization of pure polysaccharides from this species. Additionally in vivo experiments are needed and are already underway.

  10. Immunoreactivity between venoms and commercial antiserums in four Chinese snakes and venom identification by species-specific antibody.

    Gao, Jian-Fang; Wang, Jin; Qu, Yan-Fu; Ma, Xiao-Mei; Ji, Xiang

    2013-01-31

    We studied the immunoreactivity between venoms and commercial antiserums in four Chinese venomous snakes, Bungarus multicinctus, Naja atra, Deinagkistrodon acutus and Gloydius brevicaudus. Venoms from the four snakes shared common antigenic components, and most venom components expressed antigenicity in the immunological reaction between venoms and antiserums. Antiserums cross-reacted with heterologous venoms. Homologous venom and antiserum expressed the highest reaction activity in all cross-reactions. Species-specific antibodies (SSAbs) were obtained from four antiserums by immunoaffinity chromatography: the whole antiserum against each species was gradually passed through a medium system coated with heterologous venoms, and the cross-reacting components in antiserum were immunoabsorbed by the common antigens in heterologous venoms; the unbound components (i.e., SSAbs) were collected, and passed through Hitrap G protein column and concentrated. The SSAbs were found to have high specificity by western blot and enzyme-linked immunosorbent assay (ELISA). A 6-well ELISA strip coated with SSAbs was used to assign a venom sample and blood and urine samples from the envenomed rats to a given snake species. Our detections could differentiate positive and negative samples, and identify venoms of a snake species in about 35 min. The ELISA strips developed in this study are clinically useful in rapid and reliable identification of venoms from the above four snake species. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Comparative study of anticoagulant and procoagulant properties of 28 snake venoms from families Elapidae, Viperidae, and purified Russell's viper venom-factor X activator (RVV-X).

    Suntravat, Montamas; Nuchprayoon, Issarang; Pérez, John C

    2010-09-15

    Snake venoms consist of numerous molecules with diverse biological functions used for capturing prey. Each component of venom has a specific target, and alters the biological function of its target. Once these molecules are identified, characterized, and cloned; they could have medical applications. The activated clotting time (ACT) and clot rate were used for screening procoagulant and anticoagulant properties of 28 snake venoms. Crude venoms from Daboia russellii siamensis, Bothrops asper, Bothrops moojeni, and one Crotalus oreganus helleri from Wrightwood, CA, had procoagulant activity. These venoms induced a significant shortening of the ACT and showed a significant increase in the clot rate when compared to the negative control. Factor X activator activity was also measured in 28 venoms, and D. r. siamensis venom was 5-6 times higher than those of B. asper, B. moojeni, and C. o. helleri from Wrightwood County. Russell's viper venom-factor X activator (RVV-X) was purified from D. r. siamensis venom, and then procoagulant activity was evaluated by the ACT and clot rate. Other venoms, Crotalus atrox and two Naja pallida, had anticoagulant activity. A significant increase in the ACT and a significant decrease in the clot rate were observed after the addition of these venoms; therefore, the venoms were considered to have anticoagulant activity. Venoms from the same species did not always have the same ACT and clot rate profiles, but the profiles were an excellent way to identify procoagulant and anticoagulant activities in snake venoms.

  12. [Preliminary results of an herpetology investigation in sugar cane plantation in Democratic Republic of Congo].

    Malukisa, J; Collet, M; Bokata, S; Odio, W

    2005-11-01

    Out of the 3,000 species of snakes described in the world, 163 are currently known from D.R. of Congo. We performed a systematic survey in sugar-cane plantations of the Sugar Company of Kwilu-Ngongo (Bas-Congo), located at 160 km South-West from Kinshasa and exploiting nearly 10,000 ha. The plantation is divided into 3 sectors in the middle of which we deposited barrels filled of formaldehyde. All the employees of the Sugar Company of Kwilu-Ngongo were requested to collect encountered snakes and put them in the nearest barrel. Between August 9th and September 21st, 2004, we collected 36 snakes in two different sites, revealing the presence of 3 families and 12 species. The most abundant species in Causus maculatus (47% in the first site--Point 8--and 29% in the second site--Point 13). The most poisonous and dangerous species were captured only in the first site--point 8, and were Dendroaspis jamesoni and Naja melanoleuca, both young.

  13. Water quality assessment and flora study of desert thar and nagarparkar district tharparkar, sindh Pakistan

    Leghari, S.M.; Mahar, M.A.; Khuhawar, M.Y.; Jahangir, T.M.

    2007-01-01

    A number of water samples (24) were collected from wells, water pumps, natural and artificial depressions from Naukot, Vajuto, Mithi, Islamkot, Virawah and Nagarparkar area and analyzed on the site and at the laboratories for 18 different parameters. There was a wide variation in water quality; conductivity 157 to 41400 micro S/m and total dissolved solids 100 to 26500 mg/L. The highest values were observed at Virawah area and lowest at an artificial depression of rainwater within Nagarparkar town. The higher vegetation of Thar region consists mainly of thorny or prickly shrubs and perennial herbs capable of drought resistance as Calligonum polygonoides, Aerva javanica, Salvadora oleoides, Acacia senegal, Capparis decidua, Tamarix aphylla, Prosopis spicigera, Leptadenia pyrotechnica and Zizyphus nummularia. During rainy season when dunes are covered with grasses and other herbs Salvadora oleoides, Capparis decidua, and Tamarix aphylla were found scattered in Thar area. Acacia leucophloea, Acacia senegal, Salvadora oleoides, Commiphora mukul, Barleria prionitis, Blepharis sindica, Euphorbia caudicifolia were found on dry and rocky area. Rainwater pools contain total 83 algal sp; 37 sp belonging to Cyanophyta; 23 sp Volocothyta; 10 sp Chlorophyta; 3 sp Charophyta; 10 sp Bacillarophyta; some algal species found epiphytic on aquatic plants such as Chaetophora pisiformis, Stigeoclonium subsecundum, Oedogonium sp. Spirogyra rhizobrachialis, S. fluviatilis and Gloeotrichia natans attached to Najas minor, Nymphaea stellata, and Typha domingensis. (author)

  14. Removal of Metal Nanoparticles Colloidal Solutions by Water Plants

    Olkhovych, Olga; Svietlova, Nataliia; Konotop, Yevheniia; Karaushu, Olena; Hrechishkina, Svitlana

    2016-11-01

    The ability of seven species of aquatic plants ( Elodea canadensis, Najas guadelupensis, Vallisneria spiralis L., Riccia fluitans L., Limnobium laevigatum, Pistia stratiotes L., and Salvinia natans L.) to absorb metal nanoparticles from colloidal solutions was studied. It was established that investigated aquatic plants have a high capacity for removal of metal nanoparticles from aqueous solution (30-100%) which indicates their high phytoremediation potential. Analysis of the water samples content for elements including the mixture of colloidal solutions of metal nanoparticles (Mn, Cu, Zn, Ag + Ag2O) before and after exposure to plants showed no significant differences when using submerged or free-floating hydrophytes so-called pleuston. However, it was found that the presence of submerged hydrophytes in aqueous medium ( E. canadensis, N. guadelupensis, V. spiralis L., and R. fluitans L.) and significant changes in the content of photosynthetic pigments, unlike free-floating hydrophytes ( L. laevigatum, P. stratiotes L., S. natans L.), had occur. Pleuston possesses higher potential for phytoremediation of contaminated water basins polluted by metal nanoparticles. In terms of removal of nanoparticles among studied free-floating hydrophytes, P. stratiotes L. and S. natans L. deserve on special attention.

  15. The synergistic effects of 2,4-D dimethyl amine and propanil herbicides on weed population in rice agroecosystem

    Nashriyah Mat; Ramli Ishak; Sabri Junoh; Ismail Sahid

    2002-01-01

    Four treatments with the herbicides 2,4-D dimethyl amine and propanil were carried out in two consecutive rice planting seasons, to study the synergistic effect of 2,4-D dimethyl amine and propanil on rice weed populations at Pasir Panjang, the Northwest Selangor Project (PBLS), Projek Barat Laut Selangor) rice granary area. The treatments were control, 1x recommended rate (single dose), 2x recommended rate (double dose) of 2,4-D dimethyl amine and farmer practice. In all plots, propanil herbicide was applied at similar rate. Among the ecological indices measured were Simpson Index of diversity and importance (I.V.). A total number of 19 weed species was identified and the most common important weed was Najas graminae Del. The second most commonly found important weed was Scirpus lateriflorus Gmel. Other important weeds frequently found were Echinochloa crus-galli (L.) Beauv. and Fimbristylis miliacea (L.) Vahl. In the rice agroecosystem, species diversity of weeds was affected but total weed biomass was not affected synergistically by the mixture of 2,4-D dimethyl amine and propanil. The negative synergistic effect of 2,4-D dimethyl amine and propanil was to increase the total biomass of Scirpus lateriflorus, at 2x recommended dose rate of 2,4-D dimethyl amine. (Author)

  16. Diversity of Snakes in Rajegwesi Tourism Area, Meru Betiri National Park

    Aji Dharma Raharjo

    2015-02-01

    Full Text Available Rajegwesi tourism area is one of the significant tourism areas in Meru Betiri National Park, East Java, Indonesia. The area rich in term of biodiversity which are potential for developed as natural tourism attraction.  The aim of this study is to identify snakes species diversity and its distribution in Rajegwesi tourism area. Field survey was done in Rajegwesi area, namely swamps forest, residential area, rice fields, agriculture area (babatan, resort area, and Plengkang cliff. This study found some snakes, encompasses Colubridae (10 species, Elapidae (four species, and Phytonidae (one species. There are Burmese Python (Python reticulatus, Red-necked Keelback (Rhabdophis subminiatus, Painted Bronzeback Snake (Dendrelaphis Pictus, Black Copper Rat Snake (Coelognathus flavolineatus, Radiated Rat Snake (C. radiatus, Striped Keelback (Xenochrophis vittatus, Checkered Keelback (X. piscator, Spotted Ground Snake (Gongyosoma balioderius, Gold-ringed Cat Snake (Boiga dendrophila, Common Wolf Snake (Lycodon capucinus, Banded Wolf snake (L. subcinctus, Cobra (Naja sputatrix, King Cobra (Ophiophagus hannah, Malayan Krait (Bungarus candidus, and Banded Krait (B. fasciatus was found. These snake habitats distributes at 21 coordinate points. Keywords: conservation, ecotourism, snakes.

  17. Freshwater Plants Synthesize Sulfated Polysaccharides: Heterogalactans from Water Hyacinth (Eicchornia crassipes

    Nednaldo Dantas-Santos

    2012-01-01

    Full Text Available Sulfated polysaccharides (SP are found mainly in seaweeds and animals. To date, they have only been found in six plants and all inhabit saline environments. Furthermore, there are no reports of SP in freshwater or terrestrial plants. As such, this study investigated the presence of SP in freshwaters Eichhornia crassipes, Egeria densa, Egeria naja, Cabomba caroliniana, Hydrocotyle bonariensis and Nymphaea ampla. Chemical analysis identified sulfate in N. ampla, H. bonariensis and, more specifically, E. crassipes. In addition, chemical analysis, FT-IR spectroscopy, histological analysis, scanning electron microscopy (SEM and energy-dispersive X-ray analysis (EDXA, as well as agarose gel electrophoresis detected SP in all parts of E. crassipes, primarily in the root (epidermis and vascular bundle. Galactose, glucose and arabinose are the main monosaccharides found in the sulfated polysaccharides from E. crassipes. In activated partial thromboplastin time (APTT test, to evaluate the intrinsic coagulation pathway, SP from the root and rhizome prolonged the coagulation time to double the baseline value, with 0.1 mg/mL and 0.15 mg/mL, respectively. However, SP from the leaf and petiole showed no anticoagulant activity. Eichornia SP demonstrated promising anticoagulant potential and have been selected for further studies on bioguided fractionation; isolation and characterization of pure polysaccharides from this species. Additionally in vivo experiments are needed and are already underway.

  18. Public health aspects of snakebite care in West Africa: perspectives from Nigeria.

    Habib, Abdulrazaq G

    2013-10-17

    Snakebite envenoming is a major public health problem among rural communities of the Nigerian savanna. The saw-scaled or carpet viper (Echis ocellatus) and, to a lesser extent, the African cobras (Naja spp.) and puff adders (Bitis arietans) have proved to be the most important cause of mortality and morbidity. The main clinical features of E. ocellatus envenoming are systemic hemorrhage, incoagulable blood, shock, local swelling, bleeding and, occasionally, necrosis. Bites may be complicated by amputation, blindness, disability, disfigurement, mutilation, tissue destruction and psychological consequences. Antivenom remains the hallmark and mainstay of envenoming management while studies in Nigeria confirm its protection of over 80% against mortality from carpet-viper bites. However, the availability, distribution and utilization of antivenom remain challenging although two new antivenoms (monospecific EchiTab G and trispecific EchiTab ICP-Plus) derived from Nigerian snake venoms have proven very effective and safe in clinical trials. A hub-and-spoke strategy is suggested for broadening antivenom access to endemic rural areas together with instituting quality assurance, standardization and manpower training. With the advent of antivenomics, national health authorities must be aided in selecting and purchasing antivenoms appropriate to their national needs while manufacturers should be helped in practical ways to improve the safety, efficacy and potential coverage against snake venoms and pricing of their products.

  19. Comparative sensitivity of five species of macrophytes and six species of algae to atrazine, metribuzin, alachlor, and metolachlor

    Fairchild, James F.; Ruessler, Shane; Carlson, A. Ron

    1998-01-01

    This study determined the relative sensitivity of five species of aquatic macrophytes and six species of algae to four commonly used herbicides (atrazine, metribuzin, alachlor, and metolachlor). Toxicity tests consisted of 96-h (duckweed and algae) or 14-d (submerged macrophytes) static exposures. The triazine herbicides (atrazine and metribuzin) were significantly more toxic to aquatic plants than were the acetanilide herbicides (alachlor and metolachlor). Toxicity studies ranked metribuzin > atrazine > alachlor > metolachlor in decreasing order of overall toxicity to aquatic plants. Relative sensitivities of macrophytes to these herbicides decreased in the order of Ceratophyllum > Najas > Elodea > Lemna > Myriophyllum. Relative sensitivities of algae to herbicides decreased in the order of Selenastrum > Chlorella > Chlamydomonas > Microcystis > Scenedesmus > Anabaena. Algae and macrophytes were of similar overall sensitivities to herbicides. Data indicated that Selenastrum, a commonly tested green alga, was generally more sensitive compared to other plant species. Lemna minor, a commonly tested floating vascular plant, was of intermediate sensitivity, and was fivefold less sensitive than Ceratophyllum, which was the most sensitive species tested. The results indicated that no species was consistently most sensitive, and that a suite of aquatic plant test species may be needed to perform accurate risk assessments of herbicides.

  20. Using linoleic acid embedded cellulose acetate membranes to in situ monitor polycyclic aromatic hydrocarbons in lakes and predict their bioavailability to submerged macrophytes.

    Tao, Yuqiang; Xue, Bin; Yao, Shuchun

    2015-05-19

    To date no passive sampler has been used to predict bioavailability of contaminants to macrophytes. Here a novel passive sampler, linoleic acid embedded cellulose acetate membrane (LAECAM), was developed and used to in situ measure the freely dissolved concentrations of ten polycyclic aromatic hydrocarbons in the sediment porewaters and the water columns of two lakes in both winter and summer and predict their bioavailability to the shoots of resident submerged macrophytes (Potamogeton malainus, Myriophyllum spicata, Najas minor All., and Vallisneria natans (Lour.) Hara). PAH sampling by LAECAMs could reach equilibrium within 21 days. The influence of temperature on LAECAM-water partition coefficients was 0.0008-0.0116 log units/°C. The method of LAECAM was comparable with the active sampling methods of liquid-liquid extraction combined with fDOC adjustment, centrifugation/solid-phase extraction (SPE), and filtration/SPE but had several advantages. After lipid normalization, concentrations of the PAHs in LAECAMs were not significantly different from those in the macrophytes. In contrast, concentrations of the PAHs in the triolein containing passive sampler (TECAM) deployed simultaneously with LAECAM were much higher. The results suggest that linoleic acid is more suitable than triolein as the model lipid for passive samplers to predict bioavailability of PAHs to submerged macrophytes.

  1. Weed populations and their buried seeds in rice fields of the MUDA area

    Ismail Sahid; Noor Faezah Zainuddin; Ho Nai Kin

    2002-01-01

    A total of 25 weed species belonging to 15 families were found in rice fields near Kampung Tandop, in the Muda Irrigation Scheme, Kedah, Malaysia. The dominant weeds in dry-seeded rice were Utricularia aurea Lour., Fimbristylis miliacea (L.) vahl., Echinochloa crusgalli (L.) Beauv., Monochoria vaginalis (Burm. Q Presl. and Najas graminea (Del.) Redl. In wet-seeded rice, the dominant species were N. graminea, Lemna minor L., Sphenoclea zeylanica Gaertn., U. aured, and Sagittaria guayanensis H. B. K., while in volunteer seedling rice fields, the dominant species were Echinochloa colonum (L.) Link., Fimbristylis alboviridis C. B. Clarke, E miliacea, Cyperus babakan Steud. and Fuirena umbellata Rottb. Dry-seeded rice fields contained the highest number of weed seeds (930 910/m 2 in the top 15 cm of soil); volunteer seedling rice fields contained 793.162/m 2 and wet-seeded rice fields 712 228/m 2 . In general, the seed numbers declined with increasing soil depth. At 1015 cm depth, seeds of U aurea and S. zeylanica were the most abundant in dry and wet-seeded rice fields, whilst seeds of Scirpusjuncoides Roxb. and E miliacea were most abundant in volunteer seedling fields. (Author)

  2. Significance of Two New Pleistocene Plant Records from Western Europe

    Field, Michael H.; Velichkevich, Felix Y.; Andrieu-Ponel, Valerie; Woltz, Phillipe

    2000-09-01

    The first records of extinct Caulinia goretskyi (Dorofeev) Dorofeev (synonym Najas goretskyi Dorofeev) in western Europe and of Potamogeton occidentalis M.H. Field sp. nov. were obtained from plant macrofossil analyses of Middle Pleistocene temperate stage deposits exposed at Trez Rouz, Brittany, France. Palynological assemblages recovered suggest correlation with the Holsteinian Stage. This discovery greatly expands the western limit of the paleogeographical distribution of Caulinia goretskyi. The record of Potamogeton occidentalis indicates an affinity with the eastern Asiatic flora, as the fruits resemble those of the extant Potamogeton maackianus A. Bennett. Other extinct Pleistocene species related to P. maackianus have been described, and it is possible to follow the development of this group through the Pleistocene in the European fossil record. These new finds illustrate the importance of a complete paleobotanical approach (both plant macrofossil and palynological analyses). The plant macrofossil assemblages not only provide detailed insight into local vegetation and environment, because they are often not transported long distances (in temperate areas) and can frequently be identified to species level; they can also offer the opportunity to investigate Pleistocene evolutionary trends.

  3. Code of Practice on the International Transboundary Movement of Radioactive Waste; Kodeks Praktiki V Oblasti Meikduiarodnog0 Transgranichnogo Peremeshhenija Radioaktivnyh Othodov

    NONE

    1990-11-15

    On 21 September 1990, the General Conference, by resolution GC(XXXIV)/RES/530, adopted a Code of Practice on the International Transboundary Movement of Radioactive Waste and requested the Director General - inter alia - to take all necessary steps to ensure wide dissemination of the Code of Practice at both the national and the international level. The Code of Practice was elaborated by a Group of Experts established pursuant to resolution GC(XXXII)/RES/490 adopted by the General Conference in 1988. The text of the Code of Practice is reproduced herewith for the information of all Member States [Russian] 21 sentjabrja 1990 goda General'naja konferencija prinjala rezoljuciju GC(XXXIV)/RES/530 o Kodekse praktiki v oblasti mezhdunarodnogo transgranichnogo peremeshhenija radioaktivnyh othodov i predlozhila General'nomu direktoru , v chastnosti, prinjat' vse neobhodimye mery dlja obespechenija shirokogo rasprostranenija Kodeksa praktiki kak na nacional'nom, tak i na mezhdunarodnom urovnjah. Kodeks praktiki byl podgotovlen gruppoj jekspertov , uchrezhdennoj vo ispolnenie rezoljucii GC(XXXII)/RES/490, prinjatoj General'noj konferenciej v 1988 godu. Tekst Kodeksa praktiki vosproizvoditsja nizhe dlja informacii vseh gosudarstv-chlenov.

  4. Trypanosoma cf. varani in an imported ball python (Python reginus) from Ghana.

    Sato, Hiroshi; Takano, Ai; Kawabata, Hiroki; Une, Yumi; Watanabe, Haruo; Mukhtar, Maowia M

    2009-08-01

    Peripheral blood from a ball python (Python reginus) imported from Ghana was cultured in Barbour-Stoenner-Kelly (BSK) medium for Borrelia spp. isolation, resulting in the prominent appearance of free, and clusters of, trypanosomes in a variety of morphological forms. The molecular phylogenetic characterization of these cultured trypanosomes, using the small subunit rDNA, indicated that this python was infected with a species closely related to Trypanosoma varani Wenyon, 1908, originally described in the Nile monitor lizard (Varanus niloticus) from Sudan. Furthermore, nucleotide sequences of glycosomal glyceraldehyde-3-phosphate dehydrogenase gene of both isolates showed few differences. Giemsa-stained blood smears, prepared from the infected python 8 mo after the initial observation of trypanosomes in hemoculture, contained trypomastigotes with a broad body and a short, free flagellum; these most closely resembled the original description of T. varani, or T. voltariae Macfie, 1919 recorded in a black-necked spitting cobra (Naja nigricollis) from Ghana. It is highly possible that lizards and snakes could naturally share an identical trypanosome species. Alternatively, lizards and snakes in the same region might have closely related, but distinct, Trypanosoma species as a result of sympatric speciation. From multiple viewpoints, including molecular phylogenetic analyses, reappraisal of trypanosome species from a wide range of reptiles in Africa is needed to clarify the relationship of recorded species, or to unmask unrecorded species.

  5. New and already known acanthocephalans from amphibians and reptiles in Vietnam, with keys to species of Pseudoacanthocephalus Petrochenko, 1956 (Echinorhynchidae) and Sphaerechinorhynchus Johnston and Deland, 1929 (Plagiorhynchidae).

    Amin, Omar M; Ha, Ngyuen Van; Heckmann, Richard A

    2008-02-01

    Adults of 2 new species in 2 orders of acanthocephalans obtained from the intestines of terrestrial amphibians and reptiles collected between 1998 and 2004 in Vietnam are described here. Pseudoacanthocephalus nguyenthileae n. sp. (Palaeacnthocephala: Echinorhynchidae) was collected from 5 species of terrestrial amphibians: (1) the common Sunda toad Bufo melanostictus Schneider (Bufonidae); (2) Paa verucospinosa (Bourret); (3) Gunther's Amoy frog Rana guentheri Boulenger; (4) Taipei frog R. taipehensis Denburgh (Ranidae), and (5) the Burmese whipping frog Polypedates mutus (Smith) (Racophoridae); as well as from the Chinese cobra Naja atra Cantor (Reptilia: Elapidae) and house gecko Hemidactylus frenatus Dumeril and Bibron (Reptilia: Gekkonidae). Sphaerechinorhynchus maximesospinus n. sp. (Plagiorhynchidae: Sphaerechinorhynchinae) was isolated from a king cobra Ophiophagus hannah (cantor) (Reptilia: Elapidae). Cystacanths of Porrorchis houdemeri (Joyeux and Baer, 1935) Schmidt and Kuntz, 1967 (Plagiorhynchidae: Porrorchinae) obtained from the mesenteries of banded krait Bungarus fasciatus (Schneider) (Reptilia: Elapidae), a paratenic host, are reported for the first time. Keys to the species of Pseudoacanthocephalus and Sphaerechinorhynchus are included. Characteristic features distinguishing the new species from related taxa include: P. nguyenthileae has 15-19 (usually 16-18) proboscis hook rows, each with 5-6 hooks that progressively increase in length and size posteriorly. The largest, intermediate, and smallest proboscis hooks of S. maximesospinus are the middle, anterior, and posterior hooks, respectively; the proboscis and neck are enclosed in a membrane. Morphometric characteristics of P. nguyenthileae show host-related variability.

  6. Emissions of methane and carbon dioxide during anaerobic decomposition of aquatic macrophytes from a tropical lagoon (São Paulo, Brazil Emissões de metano e dióxido de carbono da decomposição de macrófitas aquáticas de uma lagoa tropical (São Paulo, Brasil

    Irineu Bianchini Jr.

    2010-06-01

    Full Text Available AIM: Massive accumulations of aquatic sedimentary plant are the main source of CH4 and CO2 emissions in floodplain lakes. To examine this connection, this study measured CO2 and CH4 formation during anaerobic decomposition of aquatic macrophytes from a floodplain lake; METHODS: Methane formation was determined to the intrinsic characteristics of the debris, and the experimental (physical and chemical conditions. Production of CH4 and CO2 were measured during anaerobic degradation of seven aquatic macrophytes: Cabomba furcata, Cyperus giganteus, Egeria najas, Eichhornia azurea, Ludwigia inclinata, Oxycaryum cubense, and Utricularia breviscapa, all of which inhabit the littoral zone of the lagoon studied; RESULTS: Overall, methanogenesis was more sensitive to temperature variation than gross anaerobic mineralization. Although the metabolic routes that generate CO2 were always predominant, as a competing process methanogenesis was favored by increasing temperature to the detriment of CO2 formation. Although several factors (such as pH, redox potential, salinity and nutrients availability influenced yields of the final degradation products, temperature and detritus chemical composition were, in a first approach, the key factors in CH4 formation. In the oxbow lakes of the Mogi-Guaçu River Floodplain, especially Óleo Lagoon, on average, 10% of the total carbon can be regarded as the yield of CH4 formation derived from aquatic macrophyte decay, while the remaining carbon (90% became CO2.OBJETIVO: Acúmulos intensos de plantas nos sedimentos são importantes fontes de emissões de CH4 e CO2 em lagoas de várzea de inundação. Nesse estudo foram determinadas as formações de CH4 e CO2 da decomposição anaeróbia de macrófitas aquáticas de uma lagoa marginal; MÉTODOS: A formação do metano foi determinada com base nas características intrínsecas dos detritos e das condições experimentais. As produções de CH4 e CO2 foram determinadas durante

  7. Limnological variables and nutritional content of submerged aquatic macrophytes in a tropical lagoon Variáveis limnológicas e conteúdo nutricional de macrófitas aquáticas submersas em uma lagoa tropical

    Bruno dos Santos Esteves

    2010-06-01

    Full Text Available AIM: The aim of this study was to evaluate elemental composition (C, N and P and carbohydrate and lipids content of aquatic macrophytes Egeria densa, Ceratophyllum demersum and Najas marina found in a lagoon of Norte Fluminense and relate these data to limnological parameters measured in the same period; METHODS: The samples were obtained from 10 sites throughout the lagoon in July/2001 (dry season and January/2002 (rainy season with determinations limnological parameters and quantification of nutrient content and biochemical composition of the aquatic macrophytes; RESULTS: High values of electrical conductivity and alkalinity explain the spatial distribution of the studied macrophytes; and the pH values (OBJETIVO: O objetivo deste estudo foi avaliar a composição elementar (C, N e P e conteúdo de carboidratos e lipídeos das macrófitas aquáticas Egeria densa, Ceratophyllum demersum e Najas marina encontradas em uma lagoa do Norte Fluminense, e relacionar esses dados a parâmetros limnológicos medidos em igual período; MÉTODOS: As amostras foram obtidas em julho/2001 (período seco e janeiro/2002 (período chuvoso, em 10 pontos ao longo da lagoa do Campelo com determinações de parâmetros limnológicos e quantificação de componentes nutricionais e bioquímicos das macrófitas aquáticas; RESULTADOS: Elevados valores de condutividade elétrica e alcalinidade explicam a distribuição espacial das macrófitas estudadas, e os valores de pH (<9,0, supersaturação de O2 e subsaturação de CO2 sugerem uma elevada produção primária, tanto fitoplanctônica quanto de macrófitas submersas. Para os nutrientes avaliados nas macrófitas aquáticas, variações sazonais significativas foram observadas no conteúdo de fósforo total (p < 0,05, de nitrogênio total e carbono total, entretanto, sem qualquer padrão definido entre períodos sazonais e macrófitas. Observou-se tendência às maiores concentrações de P nos tecidos das macr

  8. Record of environmental and climatic changes in middle Pleistocene sediments from Łuków (eastern Poland on the basis of plant macroremains analysis

    Stachowicz-Rybka Renata

    2015-06-01

    Full Text Available Lacustrine sediments at the Łuków site bear a record of the Ferdynandovian interglacial, correlated with Marine Isotope Stage (MIS 13-15, including two warm periods of interglacial rank (climatostratigraphic units Ferdynandovian 1 and 2 separated by cooling/glaciation (Ferdynandovian 1/2. On the basis of plant macroremains analysis, the type of local vegetation in the lake and its surroundings as well as changes in climate, trophic conditions and water level were reconstructed in detail. Ferdynandovian 1 was a time of development of tall sedge swamps. The presence of Najas marina and N. minor also suggests high levels of eutrophication, particularly in the younger part of the climatic optimum. The occurrence of Zannichellia palustris indicates habitats of variable water level and high salt content. In the terminocratic phase of Ferdynandovian 1, the communities showed the reoccurrence of Betula nana, B. humilis and Larix sp., the disappearance of thermophilous trees, and the intensification of succession processes linked to climate cooling. In the cool Ferdynandovian 1/2, Betula nana and Cenococcum geophilum increased their frequencies, most likely due to enhanced supply of mineral matter to the basin. During Ferdynandovian 2, the next climate warming of interglacial rank, communities of aquatic vegetation with the highest share of thermophilous taxa included the extinct Aldrowanda borysthenica, Brasenia borysthenica, and Scirpus atroviroides, as well as Cyperus glomeratus, a species not presently found in the flora of Poland. Another cooling in the Sanian 2 (Elsterian 2 glaciation is indicated by the development of peat communities, with numerous Carex sp., Menyanthes trifoliata, Eriophorum vaginatum, and Andromeda polifolia, accompanied by the extinct Carex paucifloroides, Caulinia macrosperma, and Potamogeton praemaackianus.

  9. Mad, bad and dangerous to know: the biochemistry, ecology and evolution of slow loris venom.

    Nekaris, K Anne-Isola; Moore, Richard S; Rode, E Johanna; Fry, Bryan G

    2013-09-27

    Only seven types of mammals are known to be venomous, including slow lorises (Nycticebus spp.). Despite the evolutionary significance of this unique adaptation amongst Nycticebus, the structure and function of slow loris venom is only just beginning to be understood. Here we review what is known about the chemical structure of slow loris venom. Research on a handful of captive samples from three of eight slow loris species reveals that the protein within slow loris venom resembles the disulphide-bridged heterodimeric structure of Fel-d1, more commonly known as cat allergen. In a comparison of N. pygmaeus and N. coucang, 212 and 68 compounds were found, respectively. Venom is activated by combining the oil from the brachial arm gland with saliva, and can cause death in small mammals and anaphylactic shock and death in humans. We examine four hypotheses for the function of slow loris venom. The least evidence is found for the hypothesis that loris venom evolved to kill prey. Although the venom's primary function in nature seems to be as a defense against parasites and conspecifics, it may also serve to thwart olfactory-orientated predators. Combined with numerous other serpentine features of slow lorises, including extra vertebra in the spine leading to snake-like movement, serpentine aggressive vocalisations, a long dark dorsal stripe and the venom itself, we propose that venom may have evolved to mimic cobras (Naja sp.). During the Miocene when both slow lorises and cobras migrated throughout Southeast Asia, the evolution of venom may have been an adaptive strategy against predators used by slow lorises as a form of Müllerian mimicry with spectacled cobras.

  10. Persepsi Masyarakat Terhadap Ular sebagai Upaya Konservasi Satwa Liar Pada Masyarakat Dusun Kopendukuh, Desa Grogol, Kecamatan Giri, Kabupaten Banyuwangi

    Ajeng Sabrina Kemala Asri

    2015-04-01

    Full Text Available Ular sering dianggap sebagai hal yang membahayakan oleh masyarakat sehingga keberadaannya tidak disukai. Hal itu menyebabkan beberapa spesies ular menjadi terancam punah. Untuk itu, tujuan penelitian ini adalah mengetahui spesies ular yang hidup di Dusun Kopendukuh dan untuk mengetahui persepsi masyarakat terhadap ular secara umum. Sampel ular diperoleh melalui sampling langsung dan tak langsung. Sampling langsung dengan melakukan jelajah di area kebun dan pekarangan rumah penduduk, sedangkan sampling tak langsung dengan melakukan wawancara dengan penduduk. Kemudian sampel didokumentasi dan diidentifikasi. Kajian persepsi diperoleh melalui wawancara semi terstruktur dan kuisioner kepada responden yang diambil secara acak dengan usia minimum 10 tahun sebanyak 30 orang. Hasil wawancara dan kuisioner dianalisis menggunakan skala Likert dan analisis deskriptif. Hasil penelitian menunjukkan bahwa ditemukan dua spesies dengan metode langsung yaitu ular piton (Phyton reticulatus Schneider dan ular kacang (Dendrelaphis pictus Gmelin, sedangkan dengan metode tak langsung didapatkan sepuluh spesies ular, yaitu ular piton (Phyton reticulatus Schneider, ular sanca (Python molurus L.innaeus, ular kacang (Dendrelaphis pictus Gmelin, ular kayu (Ptyas korros Schlegel, ular irus (Naja sputatrix F. Boie, ular siloro (Boiga dendrophylla Boie, ular lajing (Chrysopelea paradise Boie, ular jali (Bungarus candidus Linnaeus, ular hijau (Gonyosoma oxycephallum F. Boie, dan ular gadung (Ahaetulla prasina Boie. Masyarakat memperoleh pengetahuan tentang peran ular dalam ekosistem dari pengalaman kehidupan sehari-hari sehingga masyarakat dapat bersikap arif terhadap keberadaan ular dalam ekosistem. Masyarakat bersedia untuk menerima dan menyampaikan informasi yang diterima dari kalangan yang dianggap memiliki kredibilitas tinggi. Oleh karena itu tindakan konservasi ular dapat dilakukan dengan baik melalui pendekatan kearifan tradisional yang ada di wilayah tersebut. Kata

  11. Lymphoid Precursor Cells and their Differentiation; Kletki-predshestvenniki v limfoidnoj tkani i ikh differentsirovka

    Chertkov, I. L. [Central' Nyj Institut Gematologii I Perelivanija Krovi, Moskva, SSSR (Russian Federation); Fridenshtejn, A. Ja. [Institut Epidemiologii, Mikrobiologii i Immunologii Im. N.F.Gamaleja, Moskva, SSSR (Russian Federation)

    1968-08-15

    The authors discuss present-day ideas concerning precursor cells in lymphoid tissues and suggest that the stem cells' decision in regard to proliferation and the path of further differentiation may be a multi-stage process, occurring at various successive phases in the histogenesis of lymphoid cells. They propose that only those elements which are capable of actively deciding (under the influence of suitable stimuli or factors inherent in the cell) in which direction the successor cells are to differentiate should be regarded as precursor cells. It is shown that there are in lymphoid tissue at least three stages with the properties of precursor cells: the stem haemopoietic cell, the antigen-sensitive cell and the immunological memory cell. The authors suggest that the working cells of immune response are transformed into immunological memory cells, and discuss the morphological characteristics of the precursor cells. (author) [Russian] V doklade rassmatrivajutsja sovremennye predstavlenija o kletkah-pred- shestvennjakah v limfoidnoj tkani. Predpolagaetsja, chto prinjatie stvolovymi kletkami reshenija o proliferacii i napravlenii dal'nejshej differencirovki mozhet predstavljat' soboj mnogostadijnyj process, proishodjashhij posledovatel'no na raznyh jetapah gistogenez a limfoidnyh kletok. Predlagaetsja rassmatrivat' v kach estv e kletok-predshestvennikov tol'ko te jelementy, kotorye sposobny aktivno (pod vlijaniem sootvetstvujushhih induktorov ili vnutrennih dlja kletki faktorov) prinimat' reshenie o napravlenii differencirovki kletok-potomkov. Dok azyvaet sja nalichie v limfoidnoj tkani, po men'shej mere, treh stadij so svojstvami kletok-predshestvennikov: stvolovaja krovetvornaja kletka, antigen-chuvstvitel'naja kletka i kletka immunologicheskoj pamjati. Vyskazyvaet sja gi poteza o transformacii rabochih kletok immunnogo otvet a v kletki immunologicheskoj pamjati. Obsuzhdaetsja morfologicheskaja harakteristika kletok-predshestvennikov. (author)

  12. Generic phylogeny, historical biogeography and character evolution of the cosmopolitan aquatic plant family Hydrocharitaceae.

    Chen, Ling-Yun; Chen, Jin-Ming; Gituru, Robert Wahiti; Wang, Qing-Feng

    2012-03-10

    Hydrocharitaceae is a fully aquatic monocot family, consists of 18 genera with approximately 120 species. The family includes both fresh and marine aquatics and exhibits great diversity in form and habit including annual and perennial life histories; submersed, partially submersed and floating leaf habits and linear to orbicular leaf shapes. The family has a cosmopolitan distribution and is well represented in the Tertiary fossil record in Europe. At present, the historical biogeography of the family is not well understood and the generic relationships remain controversial. In this study we investigated the phylogeny and biogeography of Hydrocharitaceae by integrating fossils and DNA sequences from eight genes. We also conducted ancestral state reconstruction for three morphological characters. Phylogenetic analyses produced a phylogeny with most branches strongly supported by bootstrap values greater than 95 and Bayesian posterior probability values of 1.0. Stratiotes is the first diverging lineage with the remaining genera in two clades, one clade consists of Lagarosiphon, Ottelia, Blyxa, Apalanthe, Elodea and Egeria; and the other consists of Hydrocharis-Limnobium, Thalassia, Enhalus, Halophila, Najas, Hydrilla, Vallisneria, Nechamandra and Maidenia. Biogeographic analyses (DIVA, Mesquite) and divergence time estimates (BEAST) resolved the most recent common ancestor of Hydrocharitaceae as being in Asia during the Late Cretaceous and Palaeocene (54.7-72.6 Ma). Dispersals (including long-distance dispersal and migrations through Tethys seaway and land bridges) probably played major roles in the intercontinental distribution of this family. Ancestral state reconstruction suggested that in Hydrocharitaceae evolution of dioecy is bidirectional, viz., from dioecy to hermaphroditism, and from hermaphroditism to dioecy, and that the aerial-submerged leaf habit and short-linear leaf shape are the ancestral states. Our study has shed light on the previously controversial

  13. Extreme conservation of the psaA/psaB intercistronic spacer reveals a translational motif coincident with the evolution of land plants.

    Peredo, Elena L; Les, Donald H; King, Ursula M; Benoit, Lori K

    2012-12-01

    Although chloroplast transcriptional and translational mechanisms were derived originally from prokaryote endosymbionts, chloroplasts retain comparatively few genes as a consequence of the overall transfer to the nucleus of functions associated formerly with prokaryotic genomes. Various modifications reflect other evolutionary shifts toward eukaryotic regulation such as posttranscriptional transcript cleavage with individually processed cistrons in operons and gene expression regulated by nuclear-encoded sigma factors. We report a notable exception for the psaA-psaB-rps14 operon of land plant (embryophyte) chloroplasts, where the first two cistrons are separated by a spacer region to which no significant role had been attributed. We infer an important function of this region, as indicated by the conservation of identical, structurally significant sequences across embryophytes and their ancestral protist lineages, which diverged some 0.5 billion years ago. The psaA/psaB spacers of embryophytes and their progenitors exhibit few sequence and length variants, with most modeled transcripts resolving the same secondary structure: a loop with projecting Shine-Dalgarno site and well-defined stem that interacts with adjacent coding regions to sequester the psaB start codon. Although many functions of the original endosymbiont have been usurped by nuclear genes or interactions, conserved functional elements of embryophyte psaA/psaB spacers provide compelling evidence that translation of psaB is regulated here by a cis-acting mechanism comparable to those common in prokaryotes. Modeled transcripts also indicate that spacer variants in some plants (e.g., aquatic genus Najas) potentially reflect ecological adaptations to facilitate temperature-regulated translation of psaB.

  14. Inter-Diffusion of Plasma and Magnetic Fields in Pinch and Hardcore Discharges; Interdiffusion d'un Plasma et de Champs Magnetiques dans la Striction Rectiligne et la Striction Tubulaire; Vzaimnaya diffuziya plazmy i magnitnogo polya v pinch-razryadakh i razryadakh v tverdoj serdtsevine; Interdifusion Plasma-Campo Magnetico en Descargas de Estriccion y de Nucleo Rigido

    Reynolds, P.; Lees, D. J.; Bickerton, R. J.; Hardcastle, R. A.; Wetherell, A. T.; White, B. M. [United Kingdom Atomic Energy Authority, Culham Laboratory, Abingdon, Berks. (United Kingdom)

    1966-04-15

    The inter-diffusion of plasma and magnetic field is studied in pinch and hardcore discharges in a large bore, linear discharge tube (TIBER). The variation with magnetic field configuration, initial pressure, peak current, pre-heat conditions and rise time is found. The rapid ('anomalous') field diffusion found in the pinch case is due to a hydromagnetic rather than an electrostatic instability. (author) [French] Les auteurs etudient l'interdiffusion d'un plasma et de champs magnetiques dans la striction rectiligne et la striction tubulaire, au moyen d'une chambre a decharge droite de grand diametre (TIBER). Ils en determinent les variations selon la configuration du champ magnetique, la pression initiale, le courant maximum, les conditions de preechauffage et le temps de montee. La diffusion du champ rapide (anormale) constatee dans le cas de la striction rectiligne s'explique par une instabilite hydromagnetique et non par une instabilite electrostatique. (author) [Spanish] Se estudia la interdifusion plasma-campo magnetico en descargas de estriccion y de nucleo rigido utilizando una camara lineal de descarga de gran diametro interno (TIBER). Se determina la variacion segun la configuracion del campo magnetico, la presion inicial, la intensidad maxima de corriente, las condiciones de precalentamiento y el tiempo de crecimiento. La rapida difusion de los campos ('difusion anomala') observada en el caso de la estriccion se debe mas a una inestabilidad hidromagnetica que a una electrostatica. (author) [Russian] Vzaimnaja diffuzija plazmy i magnitnogo polja issleduetsja v pinch-razrjadah i razrjadah v tverdoj serdcevine v linejnoj razrjadnoj trubke bol'shogo diametra (Tiber). Opredeljajutsja izmenenie konfiguracii magnitnogo polja, nachal'noe davlenie, pikovyj tok, uslovija predvaritel'nogo nagreva i vremja pod'ema. Pokazyvaetsja, chto bystraja (''anomal'naja'') diffuzija polja, ustanovlennaja pri pinche, imeet mesto skoree iz-za gidromagnitnoj, chem iz

  15. Non destructive assay of nuclear LEU spent fuels for burnup credit application

    Lebrun, A.; Bignan, G.

    2001-01-01

    Criticality safety analysis devoted to spent fuel storage and transportation has to be conservative in order to be sure no accident will ever happen. In the spent fuel storage field, the assumption of freshness has been used to achieve the conservative aspect of criticality safety procedures. Nevertheless, after being irradiated in a reactor core, the fuel elements have obviously lost part of their original reactivity. The concept of taking into account this reactivity loss in criticality safety analysis is known as Burnup credit. To be used, Burnup credit involves obtaining evidence of the reactivity loss with a Burnup measurement. Many non destructive assays (NDA) based on neutron as well as on gamma ray emissions are devoted to spent fuel characterization. Heavy nuclei that compose the fuels are modified during irradiation and cooling. Some of them emit neutrons spontaneously and the link to Burnup is a power link. As a result, burn-up determination with passive neutron measurement is extremely accurate. Some gamma emitters also have interesting properties in order to characterize spent fuels but the convenience of the gamma spectrometric methods is very dependent on characteristics of spent fuel. In addition, contrary to the neutron emission, the gamma signal is mostly representative of the peripheral rods of the fuels. Two devices based on neutron methods but combining different NDA methods which have been studied in the past are described in detail: 1. The PYTHON device is a combination of a passive neutron measurement, a collimated total gamma measurement, and an online depletion code. This device, which has been used in several Nuclear Power Plants in western Europe, gives the average Burnup within a 5% uncertainty and also the extremity Burnup, 2. The NAJA device is an automatic device that involves three nuclear methods and an online depletion code. It is designed to cover the whole fuel assembly panel (Active Neutron Interrogation, Passive Neutron

  16. Biomonitoring of selected freshwater macrophytes to assess lake trace element contamination: a case study of Nal Sarovar Bird Sanctuary, Gujarat, India

    Rita N. KUMAR

    2006-02-01

    Full Text Available A biomonitoring study was carried out at Nal Sarovar Bird Sanctuary, a proposed Ramsar site, Gujarat State, India, to ascertain the degree of trace element contamination. The study focused on assessment of trace element contamination in certain aquatic macrophytes to be used as biomonitors, in comparison with the sediments (abiotic monitor for heavy metal pollution. Good information was provided by analyzing roots, stems and leaves of native aquatic plants (biomonitors represented by eight species: Bergia odorata, Hydrilla verticillata, Ipomoea aquatica, Najas graminea, Nelumbo nucifera, Phragmites karka, Typha angustata and Vellisnaria spiralis, alongwith surface sediments and water, were analyzed for Cd, Co, Cu, Cu, Ni, Pb and Zn contamination. The highest concentrations of the trace elements were measured in Ipomoea aquatica and the lowest in Bergia odorata. Based on the concentration and toxicity status observed in the lake's vegetation, the six metals are arranged in the following decreasing order: Zn > Cu > Ni > Co > Pb > Cd. Compared with the standard, normal and critical toxicity range in plants, the detected values of Cd and Pb falls within normal range, while that of Co, Ni and Cu were within the critical range. However, Zn showed the highest concentration and alarming toxicity levels, which is considered as one of the most hazardous pollutants in Nal Sarovar Bird Sanctuary. Certain aquatic macrophytes species are also proposed as biomonitors for the investigated heavy metal pollutants. Such result was significant in the plant species such as Ipomoea aquatica and Phragmites karka, which are the two most useful species in biomonitoring studies due to their ability to accumulate elements in high concentration in the roots and their availability throughout the year. The results showed the significant difference in accumulation rate of some metals like Zn, Cu and Ni in different plant organs, which showed more accumulation in root than

  17. The Metabolism of Tritium-Labelled Epinephrine in Man; Metabolisme de l'Adrenaline Tritiee dans l'Organisme Humain; 041c 0435 0414 ; Metabolismo de la Adrenalina Marcada con Tritio en el Hombre

    Labrosse, E. H.; Axelrod, J.; Kopin, I. J.; Kety, S. S. [National Institute of Health, Bethesda, MD (United States)

    1962-02-15

    nuevos metabolitos. En 12 varones normales, el 92,6 {+-} 7,7% del tritio de la adrenalina-3 administrada se excreto por la orina al cabo de 54 h. Este tritio estaba repartido entre los siguientes compuestos : adrenalina sin alterar 6,8 {+-} 1,5%, metanefrina libre 5,2 {+-} 1,1%, glucuronato de metanefrina 6,0 {+-} 1,5%, sulfato de metanefrina 29,5 {+-} 9,0%, 3-metoxi-4-hidroxifenilglicol 7,1 {+-} 1,4%, acido 3,4-dihidroximandelico libre y conjugado 1,6 {+-} 0,6% y acido 3-metoxi-4-hidroximandelico 41,2 {+-} 8,4%. Como demuestran estos experimentos y otros similares, el empleo de la adrenalina tritiada permite formarse una idea mucho mas clara del metabolismo de esta importante hormona en el hombre. (author) [Russian] Predstavljaet interes issledovanie metabolizma adrenalina u cheloveka. Izuchenie metabolizma adrena- lina u zhivotnyh pokazalo vozmozhnye korni ego metabolizma, no dozy radio- aktivnosti i katehin amina byli vyshe urovnej, javljajushhihsja bezopasnymi dlja cheloveka. Rannie issledovanija metabolizma jetogo gormona u cheloveka ogranivalis' otnositel'no nizkoj udel'noj aktivnost'ju mechenogo adrjonalina. Ispol'- zovanie tritirovannogo adrenalina (7-N{sup 3}-s1)-adrenalin-s1-kilaja sol') pozvolilo provesti bolee polnoe vosstanovlenie vvodimoj raidoaktivnosti, a bolee vyso- kaja udel'naja aktivnost' (vyshe 300 {mu}c/mg) pozvolila izolirovat' i opredelit' kolichestvo novyh metabolitev. Y 12 muzhchin 92,6 {+-} 7,7% tritija v vvedennom N{sup 3}-adrenaline vyshlo v mochu cherez 54 chasa posle vvedenija tritirovannogo adrenalina. Mechennyj tritiem sostav mochi okazalsja sledujushhim: neizmenennyj adrenalin 6,8 {+-} 1,5%, svobod- nyj metanefrin (metanephrino) 5,2 {+-} 1,1%, metanefrinovyj gljukuronid (glucuronide) 6,0 {+-} 1,5 % , metanefrinovyj sul'fat 29,5 {+-}9,0%, Z-metoksi-4- gidrooksifenilglikol' 7,1 {+-} 1 , 4 % , svobodnaja i soprjazhennaja 3,4-dioksimin- dal'naja kislota 1,6 {+-} 0,6% i Z-metoksi-4-oksimindal'naja kislota 41,2 {+-} 8,4%. Podtverzhdennoe jetim

  18. Randomised controlled double-blind non-inferiority trial of two antivenoms for saw-scaled or carpet viper (Echis ocellatus envenoming in Nigeria.

    Isa S Abubakar

    Full Text Available BACKGROUND: In West Africa, envenoming by saw-scaled or carpet vipers (Echis ocellatus causes great morbidity and mortality, but there is a crisis in supply of effective and affordable antivenom (ISRCTN01257358. METHODS: In a randomised, double-blind, controlled, non-inferiority trial, "EchiTAb Plus-ICP" (ET-Plus equine antivenom made by Instituto Clodomiro Picado was compared to "EchiTAb G" (ET-G ovine antivenom made by MicroPharm, which is the standard of care in Nigeria and was developed from the original EchiTAb-Fab introduced in 1998. Both are caprylic acid purified whole IgG antivenoms. ET-G is monospecific for Echis ocellatus antivenom (initial dose 1 vial and ET-Plus is polyspecific for E. ocellatus, Naja nigricollis and Bitis arietans (initial dose 3 vials. Both had been screened by pre-clinical and preliminary clinical dose-finding and safety studies. Patients who presented with incoagulable blood, indicative of systemic envenoming by E. ocellatus, were recruited in Kaltungo, north-eastern Nigeria. Those eligible and consenting were randomly allocated with equal probability to receive ET-Plus or ET-G. The primary outcome was permanent restoration of blood coagulability 6 hours after the start of treatment, assessed by a simple whole blood clotting test repeated 6, 12, 18, 24 and 48 hr after treatment. Secondary (safety outcomes were the incidences of anaphylactic, pyrogenic and late serum sickness-type antivenom reactions. FINDINGS: Initial doses permanently restored blood coagulability at 6 hours in 161/194 (83.0% of ET-Plus and 156/206 (75.7% of ET-G treated patients (Relative Risk [RR] 1.10 one-sided 95% CI lower limit 1.01; P = 0.05. ET-Plus caused early reactions on more occasions than did ET-G [50/194 (25.8% and 39/206 (18.9% respectively RR (1.36 one-sided 95% CI 1.86 upper limit; P = 0.06. These reactions were classified as severe in 21 (10.8% and 11 (5.3% of patients, respectively. CONCLUSION: At these doses, ET-Plus was

  19. Venom ophthalmia caused by venoms of spitting elapid and other snakes: Report of ten cases with review of epidemiology, clinical features, pathophysiology and management.

    Chu, Edward R; Weinstein, Scott A; White, Julian; Warrell, David A

    2010-09-01

    Venom ophthalmia caused by venoms of spitting elapid and other snakes: report of ten cases with review of epidemiology, clinical features, pathophysiology and management. Chu, ER, Weinstein, SA, White, J and Warrell, DA. Toxicon XX:xxx-xxx. We present ten cases of ocular injury following instillation into the eye of snake venoms or toxins by spitting elapids and other snakes. The natural history of spitting elapids and the toxinology of their venoms are reviewed together with the medical effects and management of venom ophthalmia in humans and domestic animals including both direct and allergic effects of venoms. Although the clinical features and management of envenoming following bites by spitting elapids (genera Naja and Hemachatus) are well documented, these snakes are also capable of "spraying" venom towards the eyes of predators, a defensive strategy that causes painful and potentially blinding ocular envenoming (venom ophthalmia). Little attention has been given to the detailed clinical description, clinical evolution and efficacy of treatment of venom ophthalmia and no clear management guidelines have been formulated. Knowledge of the pathophysiology of ocular envenoming is based largely on animal studies and a limited body of clinical information. A few cases of ocular exposure to venoms from crotaline viperids have also been described. Venom ophthalmia often presents with pain, hyperemia, blepharitis, blepharospasm and corneal erosions. Delay or lack of treatment may result in corneal opacity, hypopyon and/or blindness. When venom is "spat" into the eye, cranial nerve VII may be affected by local spread of venom but systemic envenoming has not been documented in human patients. Management of venom ophthalmia consists of: 1) urgent decontamination by copious irrigation 2) analgesia by vasoconstrictors with weak mydriatic activity (e.g. epinephrine) and limited topical administration of local anesthetics (e.g. tetracaine) 3) exclusion of corneal abrasions

  20. Transition Processes in Superconducting Magnetic Systems; ПЕРЕХОДНЫЕ ПРОЦЕССЫ В СВЕРХПРОВОДЯЩИХ МАГНИТНЫХ СИСТЕМАХ

    Sychev, V. V.; Zenkevich, V. B.; Andrianov, V. V. [Nauchno-Issledovatel' skij Institut Vysokih Temperatur, Moskva, SSSR (Russian Federation)

    1966-12-15

    The prospects for using MHD energy conversion depend in many ways on the feasibility of superconducting magnetic systems. The construction of large, efficient superconducting magnets requires in its turn detailed information about the phenomena occurring in the superconducting windings. The properties of superconducting windings are determined largely by the characteristic features of magnetic field penetration into the volume of the superconductor and by the processes associated with the transition of a part of the windings to the normal state. Accordingly, the programme for the development of a superconducting magnetic system for MHD generation includes investigations of these processes, in which the properties of superconducting windings are brought out most clearly. The experiments were carried out with a small solenoid. The results show that the transition of the superconducting windings to the normal state follows certain patterns. The authors also investigated processes associated with current variations in a superconducting solenoid; for example, they determined experimentally the relationship between the interlinkage of electric and magnetic circuits in the solenoid and the current, the residual interlinkage, the relationship between inductance and current, and the losses when the magnetic polarity of the solenoid is reversed, etc. They also consider the possibility of a theoretical generalization of their results. (author) [Russian] Perspektivnost' magnitogidrodinamicheskogo metoda preobrazovanija jenergii vo mnogom svjazana s vozmozhnost'ju ispol'zovanija sverhprovodjashhej magnitnoj sistemy. Dlja sozdanija bol'shih, jeffektivno rabotajushhih sverhprovodjashhih magnitov neobhodima v svoju ochered' detal'naja informacija o javlenijah, imejushhih mesto v sverhprovodjashhej obmotke. Specifika sverhprovodjashhej obmotki v znachitel'noj mere opredeljaetsja harakternymi osobennostjami proniknovenija magnitnogo polja v ob{sup e}m sverhprovodnika, a takzhe

  1. Generic phylogeny, historical biogeography and character evolution of the cosmopolitan aquatic plant family Hydrocharitaceae

    Chen Ling-Yun

    2012-03-01

    Full Text Available Abstract Background Hydrocharitaceae is a fully aquatic monocot family, consists of 18 genera with approximately 120 species. The family includes both fresh and marine aquatics and exhibits great diversity in form and habit including annual and perennial life histories; submersed, partially submersed and floating leaf habits and linear to orbicular leaf shapes. The family has a cosmopolitan distribution and is well represented in the Tertiary fossil record in Europe. At present, the historical biogeography of the family is not well understood and the generic relationships remain controversial. In this study we investigated the phylogeny and biogeography of Hydrocharitaceae by integrating fossils and DNA sequences from eight genes. We also conducted ancestral state reconstruction for three morphological characters. Results Phylogenetic analyses produced a phylogeny with most branches strongly supported by bootstrap values greater than 95 and Bayesian posterior probability values of 1.0. Stratiotes is the first diverging lineage with the remaining genera in two clades, one clade consists of Lagarosiphon, Ottelia, Blyxa, Apalanthe, Elodea and Egeria; and the other consists of Hydrocharis-Limnobium, Thalassia, Enhalus, Halophila, Najas, Hydrilla, Vallisneria, Nechamandra and Maidenia. Biogeographic analyses (DIVA, Mesquite and divergence time estimates (BEAST resolved the most recent common ancestor of Hydrocharitaceae as being in Asia during the Late Cretaceous and Palaeocene (54.7-72.6 Ma. Dispersals (including long-distance dispersal and migrations through Tethys seaway and land bridges probably played major roles in the intercontinental distribution of this family. Ancestral state reconstruction suggested that in Hydrocharitaceae evolution of dioecy is bidirectional, viz., from dioecy to hermaphroditism, and from hermaphroditism to dioecy, and that the aerial-submerged leaf habit and short-linear leaf shape are the ancestral states. Conclusions

  2. Effect of submerged, freshwater aquatic macrophytes and littoral sediments on pan evaporation in the Lake Balaton region, Hungary

    Anda, A.; Simon, B.; Soos, G.; Teixeira da Silva, J. A.; Kucserka, T.

    2016-11-01

    The evaporation (Ep) of a US Class A pan (C) with submerged, freshwater aquatic macrophytes (Potamogeton perfoliatus, Myriophyllum spicatum and Najas marina), hereafter macrophytes (Ps) and a sediment-covered bottom (S) was measured in Hungary during 2014-2015 using reference E of Shuttleworth (Eo) and Penman-Monteith crop reference evapotranspiration (crop ETo). There were two main climatic controls affecting variation in E: direct (air and water temperature) and indirect (wind-mediated change affecting the penetration of sunlight; precipitation inflow, impacting plant emergence). Lower seasonal mean Ep rates of 2.75 ± 0.89, 2.83 ± 0.91 and 3.06 ± 1.14 mm day-1 were observed in C, S and Ps, respectively, during the wet 2014. In the 2015 season, higher overall daily mean Ep rates for C, S and Ps were 3.76 ± 1.3, 4.19 ± 1.34 and 4.65 ± 1.52 mm day-1, respectively. A comparison of US Class A pan Ep containing macrophytes/sediments with that of a standard US Class A pan showed that pan coefficients (Kap and Kas) might allow for more accurate on-site lake E estimates. In 2014, seasonal mean Kas and Kap were 1.04 ± 0.14 and 1.09 ± 0.18, respectively. Slightly higher Ka values were observed during the warm and dry 2015 (Kas: 1.15 ± 0.22; Kap: 1.26 ± 0.23). A Ka value greater than 1 indicates that the Ep of a US Class A pan containing macrophytes and sediment is always higher than that of C. The calculated Eo overestimated measured Ep of Ps during the course of this study. During the warm-dry growing season, crop ETo was closest to Ep of Ps. Empirical coefficients can be useful for estimating E of lakes with submerged macrophytes more precisely. The accuracy of the estimate of Keszthely Bay's E improved by 9.85% when Ka was determined on site.

  3. New Research Required in Support of Radioactive Waste Disposal; Recherches Nouvelles Necessitees par le Probleme de l'Elimination des Dechets Radioactifs; 041d 0415 041e 0411 0425 041e 0414 ; Nuevas Investigaciones Necesarias para la Evacuacion de Desechos Radiactivos

    Schaefer, Milner B. [Inter-American Tropical Tuna Commission, Scripps Institution of Oceanography, La Jolla, CA (United States)

    1960-07-01

    los elementos radiactivos a traves de la cadena alimenticia que se encuentra en esta parte del mar. Es necesario efectuar investigaciones para poder delimitar las zonas de pesca presentes y futuras, y las zonas en que la pesca no es posible, mediante estudios basicos sobre la productividad biologica, etc. Tambien es preciso realizar estudios para determinar la velocidad de traslado de las sustancias radiactivas de una zona a otra por conveccion horizontal y por difusion turbulenta; la velocidad de dilucion por difusion, sedimentacion y transporte vertical, y la velocidad de captacion y transmision por los organismos vivos. Es necesario realizar investigaciones sobre los medios mas eficaces para someter a monitoraje las zonas de evacuacion de desechos. Algunos organismos pueden concentrar selectivamente determinados elementos; esto ofrece la posibilidad de efectuar, en condiciones economicas, jel monitoraje de desechos radiactivos de baja concentracion eliminados en el mar. Varios grupos de oceanografos de los Estados Unidos han propuesto recientemente algunos trabajos especificos de investigacion cuyo resumen aparece en esta memoria, junto con un calculo de su costo. (author) [Russian] Mnogochislennye fizicheskie, himicheskie i biologicheskie processy vlijajut na raspredelenie radioaktivnyh materialov i ih vozvrashhenie k cheloveku. Sjuda vhodjat vertikal'naja i gorizontal'naja advekcija, turbulentnaja diffuzija, vypadenija osadkov i otlozhenija, podnjatie, koncentracija i peremeshhenie organizmami, a takzhe peremeshhenie k cheloveku cherez ego pishhevye produkty iz morja. Nastojatel'no neobhodimo issledovat' svjazannye s prilivami dannye v tipichnyh gavanjah, jestuarijah i v otkrytyh beregovyh vodah, a takzhe prohozhdenie radioaktivnyh jelementov cherez pishhevye tkani v jetu chast' morja. Neobhodimo provesti issledovanija dlja togo, chtoby razgranichit' potencial'nye rybolovnye i ne rybolovnye rajony s pomoshh'ju teoreticheskogo izuchenija biologicheskoj

  4. Estudo da movimentação de plantas aquáticas imersas presentes no reservatório da UHE Eng. Souza Dias - Jupiá Movement of submerged aquatic weeds in UHE Eng. Souza Dias reservoir - Jupiá, Brazil

    D. Martins

    2005-06-01

    Full Text Available O objetivo deste estudo foi desenvolver um método para determinação de pontos de reprodução e de suas respectivas importâncias na disseminação das espécies E. densa, E. najas e C. demersum no reservatório de Jupiá. Foram monitorados dez locais nos quais se encontrou registro de altas infestações dessas espécies. Dois desses locais situam-se no rio Paraná, nas lagoas denominadas de "Ferradura" e "Pernilongo"; os outros oito sítios estão localizados no rio Tietê, nas lagoas marginais "Testemunha", "Barrenta", "Vírgula" e "Flórida", e no leito do rio nos pontos "Acima da Ponte dos Barrageiros", "Abaixo da Ponte", "Baía ao Lado da Ponte" e em frente da "Praia de Itapura". Em cada um desses sítios de reprodução foram liberados e monitorados dez blocos de plantas aquáticas imersas por mês. Os blocos possuíam volume de 0,14 cm³ e receberam uma etiqueta plástica de identificação externa e uma bóia de cor laranja, com o objetivo de serem facilmente localizadas ou visualizadas à distância. Após a soltura, cada bloco foi georreferenciado por meio de um aparelho GPS, sendo o seu deslocamento avaliado a cada 15 dias. Os sítios "Lagoa Vírgula", "Lagoa Testemunha" e "Lagoa Barrenta" destacaram-se quanto ao número de blocos (30, 20 e 19 blocos, respectivamente, que percorreram distâncias superiores a 500 m e, conseqüentemente, saíram de seus respectivos locais de reprodução. A grande maioria dos blocos permaneceu dentro da "Lagoa Flórida"; somente 12 blocos saíram e alcançaram o leito do rio Tietê. O sítio denominado "Leito Acima da Ponte" foi o que mais se destacou dentre os três localizados no leito do rio Tietê, pois forneceu 18 blocos de plantas, enquanto os sítios "Abaixo da Ponte" e "Baía ao Lado da Ponte" forneceram 15 e 14 blocos, respectivamente. O sítio "Praia de Itapura" foi o que apresentou menor importância em relação ao fornecimento de plantas imersas no rio Tietê, sendo localizadas apenas

  5. Fixation of Radioactive Waste in Glass. Part II. The Experimental Evaluation of Phosphate and Borosilicate Glasses; Fixation des Dechets Radioactifs dans le Verre, Deuxieme Partie: Evaluation Experimentale des Verres au Phosphate et au Borosilicate; 0424 0418 041a 0421 0410 0426 0418 042f 0420 0410 0414 0418 041e 0410 041a 0422 0418 0412 041d 042b 0425 041e 0422 0425 041e 0414 041e 0412 0412 0421 0422 0415 041a 041b 0415 . 0427 0410 0421 0422 042c Ii. 042d 041a 0421 041f 0415 0420 0418 041c 0415 041d 0422 0410 041b 042c 041d 0410 042f 041e 0426 0415 041d 041a 0410 041a 0410 0427 0415 0421 0422 0412 0424 041e 0421 0424 0410 0422 041d 042b 0425 0418 0411 041e 0420 041e 0421 0418 041b 0418 041a 0410 0422 041d 042b 0425 0421 0422 0415 041a 041e 041b ; Fijacion de Desechos Radiactivos en Vidrio, Parte II: Evaluacion Experimental de los Vidrios al Fosfato y al Borosilicato

    Elliot, M. N.; Grover, J. R.; Hardwick, W. H. [Atomic Energy Research Establishment, Harwell (United Kingdom)

    1963-02-15

    comme milieu de stockage, en les comparant aux verres au borosilicate. (author) [Spanish] El principal factor que es preciso tener en cuenta al proceder a la eleccion de un vidrio adecuado para almacenar por largos periodos desechos de productos de fision es el metodo de almacenamiento que se va a aplicar; el segundo factor es el grado de seguridad que ofrece la elaboracion del vidrio en un establecimiento de alta actividad. A su vez, los factores que interesan para el almacenamiento son la resistencia a la lixiviacion, la estabilidad termica y a las radiaciones y la proporcion de desechos que se pueden incorporar a la masa vitrea, mientras que las propiedados fisicas y quimicas de los aditivos vitrificantes, asi como el punto de fusion y la viscosidad del vidrio mismo, son factores que intervienen mas bien en el proceso de elaboracion. Los autores examinan la importancia relativa de todos estos factores. Exponen luego los resultados del estudio experimental de los vidrios al borosilicato que se han elegido para, los ensayos en instalacion piloto, incluso el efecto de dosis de radiacion hasta 10{sup 12} rad sobre sus propiedades fisicas y quimicas. Tambien examinaron vidrios de otras composiciones y compararon su posible utilidad, como medio de almacenamiento, con la de los vidrios al borosilicato. (author) [Russian] Steklo dlja dlitel'nogo hranenija othoDov, soderzhashhih produkty delenija, dolzhno vybirat'sja, vo-pervyh s uchetom predpolagaemogo metoda hranenija i , vo-vtoryh, s uchetom vozmozhnosti ego poluchenija na vysokoradioaktivnyh ustanovkah. Vazhnymi faktorami s tochki zrenija hranenija javljajutsja: stojkost' protiv vyshhelachivanjja, teplostojkost' i radiacionnaja stojkost', a takzhe predel'naja dolja vvodimyh othodov; chto zhe kasaetsja fizicheskogo haraktera i himicheskih svojstv jelementov, dobavljaemyh dlja stekloobrajeovanija, a takzhe tochki plavlenija i vjazkosti stekla, to jeti faktory kasajutsja processa izgotovlenija. Obsuzhdaetsja otnositel'naja

  6. The Decontamination of Low-Level Radioactive Waste Water at Risoe Research Establishment; Decontamination des Eaux Residuaires de Faible Radioactivite au Centre de Recherche de Risoe; 0414 0415 0417 0410 ; La Descontaminacion de Aguas que Reciben Desechos Radiactivos de Baja Actividad, en el Centro de Investigaciones de Risoe

    Larsen, Ib [Research Establishment Risoe, Danish Atomic Energy Commission (Denmark)

    1960-07-01

    metros del punto de descarga, sea inferior a una decima parte del valor tolerado para el agua potable. Esto corresponde a 1 milicurie por mes contenido en 5000 metros cubicos de efluente. La memoria describira el sistema de control y el colector de efluentes del laboratorio, asi como la instalacion de descontaminacion y el edificio destinado al almacenaje de los residuos. Tambien expondra experiencias en curso sobre el factor de descontaminacion y sus aspectos economicos. (author) [Russian] V svjazi s medlennym obnovleniem vody v priemnike Roskil'de fiorda v nauchno-issledovatel'skom centre rizo postroena jeffektivnaja dezaktivacion- naja ustanovka, v kotoruju vhodit isparitel'. Predusmatrivaetsja, chto aktivnost' vody fiorda na rasstojanii 10 metrov ot tochki sbrosa dolzhna byt' men'she 0.1 aktivnosti, dopuskaemoj dlja pit'evoj vody. Jeto budet sootvetstvovat' 1 millikjuri v mesjac, soderzhashhihsja v 5,000 kub. metrov ishodjashhego potoka vody. Budet dano opisanie kontrolja i sbora laboratornyh stochnyh vod, dezaktivirujushhej ustanovki i sooruzhenija dlja hranenija ostatkov. Budet predstavlen rabochij opyt dezaktivacii i jekonomiki. (author)

  7. The Relationship between Blood Injury and Absorbed Dose in Criticality Accidents; Relations entre la Deterioration du Sang et la Dose Absorbee lors d'Accidents Dus a la Formation d'un Etat Critique; Svyaz' mezhdu velichinoj pogloshchennoj dozy pri avariyakh na reaktorakh, dostigshikh kritichnosti, i narusheniem sostava krovi; Relacion entre las Hemolesiones y la Dosis Absorbida en los Accidentes de Criticidad

    Dennis, J. A. [Health Physics and Medical Division, Atomic Energy Research Establishment, Harwell (United Kingdom)

    1964-03-15

    absorbidas por el tronco humano. Examina la relacion entre estas estimaciones de dosis y los valores del diagrama del recuento sanguineo basado en el sistema de valoracion propuesto por N. Wald y G. E. Thoma para las desviaciones con respecto a los indices normales de linfocitos, neutrofilos y plaquetas en la sangre periferica. Demuestra que un parametro basado en la dosis gamma absorbida superficialmente y en la actividad del {sup 24}Na en la sangre concuerda mas satisfactoriamente con el diagrama mencionado y se presta mejor para pronosticar la gravedad de una radiolesion que cualquiera de las estimaciones dosimetricas corrientes. En general, la EBR de las dosis de particulas pesadas de retroceso deducida de estas observaciones armoniza con los valores obtenidos en experimentos realizados con perros. (author) [Russian] Dlja opredelenija dozy, pogloshhennoj poverhnost'ju tela cheloveka,vychisljalis' dozy nejtronnogo i gamma-obluchenij dlja lic, podvergshihsja oblucheniju pri avarijah na reaktorah, dostigshih kritichnosti. Izuchalas' svjaz' mezhdu jetimi dozami i ''profil'nym sostavom krovi'' po metodu M. Uolda i Dzh. Toma dlja otklonenij ot normy limfocitov, nejtrofil'nyh lejkocitov i trombocitov. Pokazano, chto velichina dozy, poluchennaja pri podschete poverhnostnoj pogloshhennoj dozy gamma- obluchenija i urovnja aktivnosti natrija-24 v krovi, v bol'shej stepeni soglasuetsja s profil'nym sostavom krovi i javljaetsja bolee nadezhnym prognosticheskim priznakom pri ocenke ste peni luch ev o go porazhenija, chem standartnye metody ocenki doz obluchenija. Otnositel'naja biologicheskaja jeffektivnost' doz tjazhelyh chastic otdachi, poluchennyh pri jetih nabljudenijah, v obshhem so glasuetsja s velichinami, poluchennymi v rezul'tate jeksperimentov na sobakah. (author)

  8. Selective Herbivory by an Invasive Cyprinid, the Rudd Scardinius erythrophthalmus

    Kapuscinski, Kevin L [SUNY-ESF, SUNY College of Environmental Science and Forestry; John, Farrell M [SUNY-ESF, SUNY College of Environmental Science and Forestry; Stehman, Stephen V [SUNY-ESF, SUNY College of Environmental Science and Forestry; Boyer, Gregory L [SUNY-ESF, SUNY College of Environmental Science and Forestry; Fernando, Danilo D [SUNY-ESF, SUNY College of Environmental Science and Forestry; Teece, Mark A [SUNY-ESF, SUNY College of Environmental Science and Forestry; Tschaplinski, Timothy J [ORNL

    2014-01-01

    1. Herbivory by non-native animals is a problem of growing concern globally, especially for ecosystems where significant native herbivores did not previously exist or have been replaced by non-natives. The rudd (Scardinius erythrophthalmus) is an omnivorous cyprinid that has a nearly global longitudinal distribution due to human translocations, yet it is unknown whether the rudd feeds selectively among aquatic macrophyte species common to North American waters. 2. We tested a null hypothesis of non-selective feeding by rudds using five species of aquatic macrophytes: Ceratophyllum demersum, Elodea canadensis, Najas flexilis, Stuckenia pectinata, and Vallisneria americana. Four rudds were placed in 15 different 890-L tanks and presented with known quantities of each macrophyte species (each tank serving as a block in a randomized complete block design). Each macrophyte bundle was weighed on six dates during a 13 d experiment. Differences in mean percent weight remaining among macrophyte species were tested using repeated measures analysis of variance. We also quantified differences among chemical attributes of the five macrophyte species and qualitatively determined if selective feeding by rudds was related to dry matter content (DMC), percent C by dry weight (%C), percent N by dry weight (%N), and the concentrations of total soluble proteins, two organic acids (aconitic and oxalic acid), total soluble phenolic compounds (<1,000 Da), nine soluble phenolic metabolites, and total phenolic compounds. 3. Selective feeding by rudds was evident, with the order of macrophyte removal (from highest to lowest) being: N. flexilis > E. canadensis > S. pectinata > V. americana > C. demersum. Selection was positively related to %C and atomic C:N, but not DMC, %N, or concentration of total soluble proteins, contrary to the expectation that rudds would select the most nutritious plants available. The concentration of aconitic acid was greatest in N. flexilis, a preferred macrophyte

  9. Improvements in the use of aquatic herbicides and establishment of future research directions

    Getsinger, K.D.; Netherland, M.D.; Grue, C.E.; Koschnick, T.J.

    2008-01-01

    Peer-reviewed literature over the past 20 years identifies significant changes and improvements in chemical control strategies used to manage nuisance submersed vegetation. The invasive exotic plants hydrilla (Hydrilla verticillata L.f. Royle) and Eurasian watermilfoil (Myriophyllum spicatum L.) continue to spread and remain the plant species of greatest concern for aquatic resource managers at the national scale. Emerging exotic weeds of regional concern such as egeria (Egeria densa Planch.), curlyleaf pondweed (Potamogeton crispus L.), and hygrophila (Hygrophila polysperma (Roxb.) T. Anders), as well as native plants such as variable watermilfoil (Myriophyllum heterophyllum Michx), and cabomba (Cabomba caroliniana Gray) are invasive outside their home ranges. In addition, there is always the threat of new plant introductions such as African elodea (Lagarosiphon major (Ridley) Moss) or narrow-leaf anacharis (Egeria najas Planchon). The registration of the bleaching herbicide fluridone in the mid 1980s for whole-lake and large-scale management stimulated numerous lines of research involving reduction of use rates, plant selectivity, residue monitoring, and impacts on fisheries. In addition to numerous advances, the specificity of fluridone for a single plant enzyme led to the first documented case of herbicide resistance in aquatic plant management. The resistance of hydrilla to fluridone has stimulated a renewed interest by industry and others in the registration of alternative modes of action for aquatic use. These newer chemistries tend to be enzyme-specific compounds with favorable non-target toxicity profiles. Registration efforts have been facilitated by increased cooperation between key federal government agencies that have aquatic weed control and research responsibilities, and regulators within the U.S. Environmental Protection Agency (USEPA). We reviewed past and current research efforts to identify areas in need of further investigation and to establish

  10. Kinetics and Mechanism of the Iron(II-Iron(III) Electron-Exchange Reaction in Mixed Solvent Media; Cinetique et Mecanisme de l'Echange d'Electrons entre Fer (II) et Fer (III), dans des Melanges de Solvants; Ikinetika i mekhanizm reaktsii ehlektronnogo obmena zheleza (I) - zheleza (III) v smeshannoj rastvoryayushchej srede; Cinetica y Mecanismo del Intercambio de Electrones Entre Fe{sup II} Y Fe{sup lII} en Mezclas de Disolventes

    Horne, R. A. [Arthur D. Little, Inc. Cambridge, MA (United States)

    1965-10-15

    de intercambio electronico entre Fe{sup II} y Fe{sup III} a diversas temperaturas, grados de acidez y fuerzas ionicas, en soluciones de aguaacetona, agua-metanol y agua-etanol. La velocidad de reaccion disminuye apreciablemente al aumentar la concentracion de agua en el ultimo de estos sistemas, tendiendo a cero con la concentracion. La energfa de activacion del intercambio es la misma en mezclas de disolventes que en solucion acuosa. La constante dielectrica efectiva que interviene entre los reactivos sigue siendo la misma que en agua pura, incluso par a soluciones en agua-etanol bastante pobres en agua. Las mediciones espectroscopicas y del intercambio electronico reflejan las alteraciones de la composicion de la vaina de solvatacion del Fe{sup III} en disolventes mixtos. Estos resultados corroboran la teoria de que el intercambio electronico se efectua por intermedio de puentes agua. (author) [Russian] Byli izmereny udel'nye kon stanty skorosti reakcii jelektronnogo obmena Fe{sup II} - Fe{sup III} n pri razlichnyh temperaturah kislotnostjah i ionnyh silah v sredah: voda - aceton, voda - metanal i voda - jetanol. Sko rost' reakcii zametno snizhaetsja s umen'sheniem koncentracii vody v poslednej sistem i priblizhaetsja k nulju, kogda koncentracija vody priblizhaetsja k nulju. Jenergija aktivaci obmena javljaetsja toj zhe samoj v.smeshannom rastvore, kak i v vodnom rastvore. Jeffektiv naja dijelektricheskaja konstanta, kotoruju 'vidjat' reagirujushhie veshhestva, prodolzhaet byt konstantoj chistoj vody dazhe v rastvorah - jetanol, vpolne rastvorimyh v vode. Iz menenija v sostave obolochki sol'vatacii Fe{sup III} v smeshannoj srede otrazhajutsja kak v jelek tronnom obmene, tak i v spektroskopicheskih izmerenijah. Jeti vyvody, poluchennye na osnov rezul'tatov v smeshannoj rastvorjajushhej srede, podtverzhdajut teoriju vodjanogo mostika pr jelektronnom obmene. (author)

  11. Preparation of Films and Sources for 4{pi} Counting; Prigotovlenie dlya 4{pi}-scheta plenok i istochnikov

    Konstantinov, A. A.; Sazonova, T. E. [Vsesojuznyj Nauchno - Isledovatel' skij Institut Im. D.I. Mendeleeva, Leningrad, SSSR (Russian Federation)

    1967-03-15

    } ) , metallizirovannye s obeih storon zolotom (10 - 15 mkg/sm{sup 2}) ili palladiem (5 - 6 mkg/sm2 ) . Dlja umen'shenija popravki na pogloshhenie 8-chastic v sloe radioaktivnogo osadka primenjaetsja special'naja obrabotka podlozhki insulinom. Predlozhen ochen' chuvstvitel'nyj i jeffektivnyj metod dlja opredelenija ravno- mernosti nanesenija aktivnogo osadka po vsej obrabotannoj insulinom ploshhadi istoch- nika s ispol'zovaniem jelektronno-zahvatnogo nuklida marganec-54 (hrom-54). Na plenku, obrabotannuju insulinom, nanosilsja rastvor soli marganec-54 (hrom-54); poluchennyj istochnik K-jelektronov Ozhe hrom-54 (marganec-54) issledovalsja v proporcional'nom 4l- schetchike. Obshhee chislo K-jelektronov Ozhe hrom-54 (marganec-54), kotorye vyhodili iz istochnika, bylo men'she na 8-12% znachenija, rasschitannogo na osnovanii chisla KH-kvantov hroma-54 (marganec-54), ispuskaemyh istochnikom, kojef- ficienta fluorescencii i chisla K-jelektronov, pogloshhennyh v plenke, kotoroe oprede- ljalos' metodom {sup s}jendvicha{sup .} Ishodja iz raznostej mezhdu raschetnym i zaregistriro- vannym chislo'm jelektronov Ozhe dlja istochnikov marganec-54 (hrom-54), obrabotannyh in- sulinom i neobrabotannyh, mozhno odnoznachno sudit' o kachestve obrabotki insulinom istochnikov. (author)

  12. Theory of Scanning and Imaging of Radioisotope Distributions; Theorie de la Scintigraphoe a Balayage ou Fixe; Teoriya skennirovaniya i izobrazhenie raspredeleniya radioizotopov; Teoria de la Exploracion y de la Obtencion de Imagenes de Distribuciones Radioisotopicas

    Cassen, B. [Department of Biophysics and Nuclear Medicine, University of California, Los Angeles, CA (United States)

    1964-10-15

    articulo que se meenciona al principio de este resumen y que, desde entonces, ha sido objeto de nuevos ensayos y perfeccionamientos. (author) [Russian] Daetsja uproshennaja osnovnaja teorija kolichestvennogo opredelenija harakteristik radioizotopnyh sistem izobrazhenija i skennirovanija. Vyvoditsja {sup c}ifrovoj pokazatel'{sup ,} chastichno zavisjashhij ot harakteristik pribora i chastichno ot ispol'zuemoj metodologii. Faktorami, vlijajushhimi na cifrovoj pokazatel', javljajutsja: chuvstvitel'nost' detektora k skorosti scheta na edinicu prostranstvennogo ugla, protivolezhashhego razreshajushhemu jele- mentu, prostranstvennyj ugol, protivolezhashhij razreshajushhemu jelementu, kolichestvo razreshajushhih jelementov, nabljudaemyh odnovremenno, kolichestvo jelementov razlozhenija vo vsem pole skennirovanija ili nabljudenija, koncentracija dozy, obshhee vremja, zatrachennoe na poluchenie izobrazhenija ili skennogrammy i skorost' scheta fona. V nastojashhem predstavlenii osnovnaja teorija sovershenstvuetsja i obsuzhdaetsja s tem, chtoby uchityvat' takie faktory, kak ''glubina fokusa'' razlozhenija, peremennaja skorost' ili peremennoe skennirovanie.vozmozhnosti peremennogo ili avtomaticheski izmenjajushhe- gosja razreshenija, sravnitel'naja razreshajushhaja sposobnost', ''holodnyh'' i ''gorjachih'' uzlov, razmer polja i ispol'zovanie special'nyh radioizotopov i vidov detektorov. Daetsja takzhe obsuzhdenie voprosov obrabotki dannyh, poluchaemyh metodami skenni- rovanija i proekcii. Analiziruetsja otnositel'naja osobennost' jeliminatorov fona i procedur kontrastnogo usilenija takih kak fotoskennirovanie i cvetnoe skennirovanie. Obsuzhdajutsja preimushhestva i vozmozhnye nedostatki zapisi na plenku original'nyh dannyh i povtornoe vosproizvedenie s pomoshh'ju kontrastnyh i fonovyh obrabatyvajushhih konturov. Dajutsja nekotorye jeksperimental'nye cifrovye dannye dlja shiroko ispol'zuemogo kom- mercheskogo skennera, a takzhe nekotorye novye dannye kasajushhiesja novogo skennera

  13. Development of Radiation-Sterilized Sea Food Products. I. Enzyme-Inactivated Cod and Halibut Patties; Essais de Radiosterilisation des Produits Alimentaires d'Origine Marine. I. Pates de Morue et de Fletan a Enzymes Inactives; Primenenie izlucheniya dlya sterilizatsii morskikh pishchevykh produktov; Preparacion de Alimentos de Origen Marino Esterilizados por Irradiacion. I. Pastelillos de Bacalao y de Hipogloso con Enzimas Inactivadas

    Sinnhuber, R. O.; Landers, Mary K.; Yu, T. C. [Department of Food Science And Technology, Oregon State University, Corvallis, OR (United States); Simon, M.; Heiligman, F. [United States Army Natick Laboratories, Natick, MA (United States)

    1966-11-15

    vodoj. Posle togo, kak kolbaski v techenie nochi ostyli i protein zatverdel, ih razrezali na lepeshki tolshhinoj 3/8 djujma, pomestili v banki i obluchili dozoj v 4,5 Mrad. Sterilizovannye oblucheniem produkty hranilis' v techenie 12 mesjacev pri temperature 72 Degree-Sign F, pri jetom periodicheski proizvodilas' ocenka kachestva, a takzhe posledstvij razlichnoj obrabotki. Jeta obrabotka vkljuchala upakovku v vakuume, vkljuchenie razlichnyh antiokislitelej i ispol'zovanie paketov dlja drevesnogo uglja. Neposredstvenno pered potrebleniem produkty pokryvalis' vzbitym testom i panirovochnymi suharjami i kak sleduet prozharivalis. Ocenka rybnyh pirozhkov proizvodilas' degustatorami, a takzhe putem izmerenija ob{sup e}ktivnyh pokazatelej, takih kak obshhie letuchie osnovanija, 2-tiobarbiturovoe kislotnoe chislo, pH i cvetnaja otrazhatel'naja sposobnost. Gruppy degustatorov (140- 170 chelovek) dali udovletvoritel'nuju ocenku vkusovyh kachestv produktov v.techenie 12 mesjacev hranenija pri temperature 72 Degree-Sign F. Hotja posle 12 mesjacev degustatory otdali predpochtenie neobluchennym kontrol'nym obrazcam, vse hranivshiesja obluchennye pirozhki poluchili polozhitel'nuju ocenku,po 9-ti bal'noj gedonicheskoj sisteme. Cvetnaja otrazhatel'naja sposobnost' sterilizovannyh oblucheniem morskih pishhevyh produktov ispol'zovalas' v kachestve merila, vyzvannogo oblucheniem potemnenija produktov i, kazhetsja, zavisit ot prodolzhitel'nosti hranenija. (author)

  14. Theory of Radioisotope Scanning; Theorie de l'Exploration au Moyen d'un Radioisotope; Matematicheskaya osnova radioizotopnogo skennirovaniya; Teoria de la Exploracion Radioisotopica

    Brownell, G. L. [Massachusetts General Hospital, Boston, MA (United States)

    1964-10-15

    optimal'nogo razreshenija i soderzhanija h raspredelenija radioizotopov. Radioijeotopnoe skennirovanie mozhno rassmatrivat' kak process sbora informacii i predstavlenija dannyh. Pervichnaja informacija zavisit ot pervonachal'nogo raspredele- nija radioizotopov. Kollimator i sistema detektirovanija obespechivajut mehanizm pereda- chi informacii, a okonchatel'naja skennogramma daet rezul'tirujushhuju informaciju. V sluchae primenenija vseh jetih metodov lish' nebol'shaja chast' informacii popadaet na okonchatel'nuju skennogrammu. Mozhno videt', chto dlja sistemy fokusirujushhego kollimatora i scintilljacionnoj ka- mery chislo otschetov na ploshhad' razreshenija kolebletsja kak chetvertaja stepen' rasstojanija razreshenija. Dlja nekotoryh vidov raspredelenija izotopov mozhno poluchit' analiticheski optimal'nuju velichinu rasstojanija razreshenija. Odnako dlja bol'shinstva sistem optimal'- noe razreshenie dolzhno opredeljat'sja opytnym putem i s pogreshnostjami. Nastojashhie prob- lemy analogichny problemam rasshifrovki snimkov v drugih oblastjah. Programma vychisli- tel'noj mashiny byla podgotovlena s tem, chtoby sodejstvovat' opredeleniju optimal'nogo razreshenija dlja razlichnyh modelej. Nastojashhaja vychislitel'naja mashina javljaetsja unikal'noj, poskol'ku v nej imeetsja promezhutochnyj otsek dlja diska i dlja schityvanija jelektronno-luchevoj trubki. Rezul'taty primenimy k konstrukcii mnogih skennirujushhih sistem. (author)

  15. The Biological Effect of Fast Neutrons and High-Energy Protons; Effets Biologiques des Neutrons Rapides et des Protons de Haute Energie; Biologicheskoe dejstvie bystrykh nejtronov i protonov vysokikh ehnergii; Efectos Biologicos de los Neutrones Rapidos y de los Protones de Elevada Energia

    Moskalev, Ju. I.; Petrovich, I. K.; Strel' cova, V. N.

    1964-03-15

    bystrymi nejtronami, tak i protonami u krys voznikajut dobrokachestvennye i zlokachestvennye opuholi razlichnyh tkanej, v tom chisle krovotvornoj, molochnyh zhelez, gipofiza, matki, jaichnikov predstatel'noj zhelezy, semennikov, shhitovidnoj zhelezy, zobnoj i podzheludochnoj zhelez, nadpochechnikov, pecheni, pochek, l e g kih, zheludochno-kishechnogo trakta, podkozhnoj kletchatki, limfaticheskih u z lov, mochevogo puzyrja i drugih. Summarnaja chastota opuholej i chislo sluchaev mul'ticentricheskogo vozniknovenija novoobrazovanij u samok v 2 - 3 raza vyshe, chem u samcov. Minimal'naja opuholevaja doza dlja molochnyh zhelez pri obluchenii nejtronami, po-vidimomu, neskol'ko nizhe 42,5 rad. Maksimal'naja chastota opuholej gipofiza obnaruzhivaetsja posle obluchenija v doze 42,5 rad. Pri jetoj zhe doze voznikajut lejkozy i opuholi shhitovidnoj zhelezy. Pri obluchenii protonami minimal'naja opuholevaja doza dlja krovotvornoj tkani i shhitovidnoj zhelezy nahoditsja v predelah 250 rad, dlja semennikov - 300 rad, dlja predstatel'noj, podzheludochnoj zhelez , podkozhnoj kletchatki - 100 rad. Posle obluchenija bystrymi nejtronami chastota opuholej semennikov, tolsto go kishechnika, pochek, pecheni okazyvaetsja uvelichennoj pri dozah 42,5 - 85 rad, kozhi i podkozhnoj kletchatki pri doze - 85 rad. Po sravneniju s protonami pri obluchenii bystrymi nejtronami opuholi voznikajut ot men'shih (primerno v 3 - 5 raz) doz obluchenija. (author)

  16. The Economical Application of Non-Destructive Testing to Reactor Components, Especially Jacket Tubing; Avantages Economiques du Controle Non Destructif des Pieces de Reacteurs, Notamment des Tubes de Gainage; Ehkonomicheskoe primenenie nedestruktivnykh ispytanij dlya reaktornykh komponentov, v chastnosti obolochechnykh trub; Aplicacion en Condiciones Economicas de Ensayos No Destructivos a las Piezas de los Reactores, en Especial a los Tubos de Revestimiento

    Renken, C. J. [Metallurgy Division Argonne National Laboratory Argonne, IL (United States)

    1965-10-15

    varias fuentes indicadoras de falsos defectos que seuelen existir tanto cuando se aplican los metodos ultrasonicos como los electromagneticos. La experiencia adquirida en la aplicacion de esos dos metodos por el Argonne National Laboratory a cantidades relativamente grandes de tubo de diversas procedencias se estudia desde el punto de vista del costo mas bajo posible a que pueda efectuarse la inspeccion por unidad de longitud del tubo de que se trate. En la presente seccion se expone ademas en forma concisa la experiencia adquirida en Argonne con los modernos metodos de impulsos electromagneticos. Se examina la influencia critica, pero generalmente inapreciada, que tienen en el costo de la inspeccion el diametro y el espesor de pared del tubo. Teniendo en cuenta que el problema de la inspeccion en condiciones economicas guarda una estrecha relacion con el numero medio de defectos admisibles, se estudian asimismo los promedios y las normas que se aplican en Argonne. Por ultimo, se enumeran los obstaculos de orden teorico y practico para reducir el costo de la inspeccion de piezas sobre esa base, y se evaluan las posibles reducciones de costo que podrian lograrse en lo futuro aplicando los metodos de ensayo ultrasonicos y electromagneticos. (author) [Russian] Ideal'naja konstrukcija reaktora, pomimo drugih zhelatel'nyh dlja nee harakteristik, ne potrebuet provedenija ispytanij bez razrushenija obolochki obrazca. Takogo ideala, kak i mnogih drugih, verojatno, nikogda ne dobit'sja. Pri ljubom proektirovanii reaktora, kogda zatraty javljajutsja vazhnym faktorom, vopros otom, mogut liego komponenty ispytyvat'sja jekonomicheski vygodno, sleduet vydvigat' odnovremenno s rassmotreniem voprosov izgotovlenija. V nastojashhij razdel vkljucheny nekotorye momenty razrabotki jetih voprosov, a takzhe obsuzhdenie vazhnosti provedenija ispytanij bez razrushenija obolochki obrazca v pis'mennyh specifikacijah. Na izgotovitelja takzhe lozhitsja otvetstvennost' ispol'zovat' pomoshh

  17. First Results of a Systematic Study of Internal Contamination Due to Fall-Out; Premiers Resultats d'une Etude Systematique des Contaminations Internes Consecutives aux Retombees Radioactives; 041f 0415 0420 0414 ; Resultados Iniciales de un Estudio Sistematico de las Contaminaciones Internas Debidas a la Precipitacion Radiactiva

    Pellerin, P.; Moroni, J. P.; Remy, M. L. [Travail du Service Central de Protection Contre les Rayonnements Ionisants, Ministere de la Sante Publique, Paris (France)

    1964-11-15

    organismo humano tendria capital importancia, pero la medicion directa de este isotopo mediante el antropogammametro no puede realizarse cuando se trata de bajas actividades. Por lo tanto, los autores procuraron evaluar el orden de magnitud de dicha carga por dos metodos diferentes: primeramente, el estudio del cesio-137, cuya concentracion en las precipitaciones radiactivas sigue una evolucion sensiblemente paralela al del estroncio-90, permite hallar una primera aproximacion. Ademas, los autores midieron la excrecion urinaria de estroncio-90 en cierto numero de sujetos, con el proposito de deducir asi la carga total o, por lo menos, encontrar un limite superior para la concentracion de dicho isotopo. (author) [Russian] S sentjabrja 1961 goda Central'naja sluzhba zashhity ot ionizirujushhih izluchenij provela svyshe 500 obsledovanij s pomosh'ju schetchika dlja izmerenija radioaktivnosti vsego organizma cheloveka. Mnogie lica obsledovalis' v techenii treh ili shesti mesjacev . Pri jetih obsledovanijah chasto ispol'zovalsja radioanaliz mochi, v celom radiohimicheskomu issledovaniju predshestvovalo sistematicheskoe izuchenie obrazcov mochi s pomosh'ju gamma-spektrometrii.Sravnitel'noe izuchenie rezul'tatov jetih razlichnyh issledovanij pozvoljaet vyjavit' nekotorye fakty, otnosjashhiesja k vnutrennemu zarazheniju v rezul'tate radioaktivnyh vypadenij: 1. Cezij-137 javljaetsja edinstvennym iskustvennym radioizotopom, kotoryj postojanno obnaruzhivalsja pri obsledovanijah s pomoshh'ju schetchika dlja izmerenija aktivnosti vsego organizma. Jevoljucija obshhego srednego soderzhanija izotopa mozhet byt' proslezhena v techenie vsego perioda vremeni, otvedennogo na vse issledovanija. Dopolnitel'no mozhno otmetit' izmenenija, i k tomu zhe obychnye, radioaktivnogo zarazhenija v zavisimosti ot pola. 2. Chto kasaetsja obychno vstrechajushhihsja slabyh aktivnostej, to nam udalos' izuchit' svjaz' mezhdu vydeleniem s mochoj cezija-137 i obshhim soderzhaniem jetogo izotopa v organizme. Rezul

  18. Injection of Plasma Blobs into A Mirror Trap With Adiabatic Plasma Compression: ''ASPA'' Device; Injection d'Amas de Plasma dans un Piege a Miroirs avec Compression Adiaba Tique - Machine 'ASPA'; Inzhektsiya plazmennykh sgustkov v probochnuyu lovushku s adiabaticheskim szhatiem plazmy. Ustanovka ''ASPA''; Inyeccion de Plasmoides en una Trampa de Espejos con Compresion Adiabatica. La Instalacion 'ASPA'

    Babichev, A. P.; Burjak, E. M.; Gorbunova, E. F.; Karchevskij, A. I.; Muromkin, Ju. A. [Institut Atomnoj Ehnergii, Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

    1966-04-15

    compresion. Investigaron tambien el paso del plasmoide a traves del espejo magnetico, para una intensidad del campo de 20 kOe como maximo. En algunos experimentos, el campo del espejo era paralelo al campo magnetico guia, en otros, antiparalelo, es decir, se creo un campo desviador con dos regiones de intensidad nula. Pudo comprobarse que el plasmoide inyectado (con un inyector de titanio o con uno coaxial) atraviesa con bastante facilidad el espejo magnetico cuando la direccion del campo del espejo coincide con la del campo magnetico guia, que no lo atraviesa cuando el campo es de tipo desviador. Basandose en estos experimentos, los autores demostraron la posibilidad de eliminar las impurezas pesadas de un plasma inyectado, utilizando una puerta magnetica pulsada que crea regiones en las que la intensidad del campo magnetico es nula y las lfneas.de fuerza magnetica se dirigen hacia las paredes de la camara. En los experimentos provisionales sobre compresion adiabatica del plasma en una trampa de espejo los autores observaron rayos X duros (de 30 keV de energia); investigaron la influencia ejercida por el campo magnetico inicial y los parametros del plasmoide sobre la intensidad y la dureza de estos rayos. (author) [Russian] Privedeny osnovnye harakteristiki ustanovki ''Aspa'', postroennoj dlja issledovanija adiabaticheskogo szhatija plazmy v lovushke s probochnoj-konfiguraciej magnitnogo polja. Vakuumnaja kamera ustanovki pomeshhaetsja v solenoide (dlina 4 metra, diametr 1 metr), na osi kotorogo mozhet sozdavat'sja prodol'noe vedushhee kvazistacionarnoe magnitnoe pole s naprjazhennost'ju do 5 kje. V kachestve istochnika dejterievoj plazmy ispol'zovalis' titanovyj inzhektor ili koaksial'naja plazmennaja pushka. Plazmennyj sgustok inzhektirovalsja vdol' osi ustanovki i postupal v rabochuju oblast' szhatija, kotoraja predstavljala soboj stekljannuju trubu diametrom 10 sm. Impul'snoe magnitnoe pole probochnoj konfiguracii sozdavalos' dvumja katushkami, rasstojanie mezhdu

  19. Comparison Of The Worth Of Critical And Exponential Measurements For Heavy-Water-Moderated Reactors; Valeur Relative des Mesures Critiques et Exponentielles pour l'Etude des Reacteurs Ralentis a l'Eau Lourde; Sravnenie tsennosti kriticheskikh i ehksponentsial'nykh izmerenij dlya reaktorov s tyazhelovodnym zamedlitelem; Valor Relativo de las Mediciones Criticas y Exponenciales para los Reactores Moderados por Agua Pesada

    Graves, W. E.; Hennelly, E. J. [Savannah River Laboratory, E.I. Du Pont De Nemours and Co., Aiken, SC (United States)

    1964-02-15

    para determinar el coeficiente termico del laplaciano para un calentamiento uniforme del reticulado. En el SRL hay una instalacion especial, el PSE, que permite establecer dicho coeficiente hasta temperaturas de 215 Degree-Sign C. En cambio, para un calentamiento no uniforme, se prefiere generalmente los conjuntos criticos. 5. Reticulados mixtos En los reactores en funcionamiento raramente se usan los reticulados uniformes simples a los cuales se aplican basicamente los experimentos exponenciales. En el SRL se recurre a los experimentos criticos con cargas mezcladas, tanto para medir los efectos directos en maquetas, como para verificar la correccion de los calculos de difusion en medios heterogeneos y bidimensionales. 6. Estudios de la criticidad en agua ligera de un combustible destinado a reticulados de agua pesada Se ha comprobado que los experimentos exponenciales del laboratorio del SRL son particularmente valiosos para los estudios de criticidad encaminados a encontrar metodos seguros de manipulacion en agua ligera del combustible enriquecido. Estos trabajos no exigen una exactitud muy grande, y cabe senalar que los estudios de tipo general del laplaciano efectuados en conjuntos exponenciales son decididamente preferibles a los estudios especializados con conjuntos criticos. (author) [Russian] Kriticheskie i jeksponencial'nye jeksperimenty dajut, kak pravilo, chastichno perekryvajushhiesja dannye po reaktornym reshetkam. V techenie poslednih desjati let v Laboratorii Savanna-River rabotali parallel'no tjazhelovodnaja kriticheskaja ustanovka PDP i jeksponencial'naja ustanovka SE. Obobshhaetsja opyt s cel'ju dat' rekomendacii v otnoshenii primenenija jetih dvuh ustanovok dlja razlichnyh jeksperimentov. Rassmatrivajutsja shest' vidov jeksperimentov: 1) . Izmerenija laplasiana v odnorodnyh izotopnyh reshetkah Osushhestvleno shirokoe sravnenie rezul'tatov, poluchennyh pri odnorodnyh kriticheskih, jeksponencial'nyh i podstanovochno-kriticheskih izmerenijah, a takzhe

  20. Vitrification of Concentrated Solutions of Fission Products: Technological Studies; Vitrification des Solutions Concentrees de Produits de Fission: Etudes Technologiques; 041e 0421 0422 0415 041a 041b 041e 0412 042b 0412 0410 041d 0418 0415 041a 041e 041d 0426 0415 041d 0422 0420 0418 0420 041e 0412 0410 041d 041d 042b 0425 0420 0410 0421 0422 0412 041e 0420 041e 0412 041f 0420 041e 0414 0423 041a 0422 041e 0412 0414 0415 041b 0415 041d 0418 042f : 0422 0415 0425 041d 0418 0427 0415 0421 041a 041e 0415 0418 0421 0421 041b 0415 0414 041e 0412 0410 041d 0418 0415 ; Vitrificacion de Soluciones Concentradas de Productos de Fision: Estudios Tecnologicos

    Bonniaud, R.; Rancon, P. [Centre d' Etudes NuclEaires, Fontenay-aux-Roses (France)

    1963-02-15

    rendimiento es del orden del 90%, y b) la volatilidad del rutenio, que sigue siendo apreciable. En cuanto a la instalacion de vitrificacion ''de cuba'', se trata de un procedimiento intermedio entre el que se acaba de describir y el de los crisoles. Luego de anadirle vidrio sinterizado y arcilla gelificante, la solucion activa se cuela continuamente en una cuba que se mantiene a 500 Degree-Sign C hasta colmarla. La calcinacion y la alimentacion son simultaneas. El nivel a que llega la masa se determina midiendo las temperaturas internas. Despues de calcinar la carga completa, el vidrio se funde y cuela por la extremidad inferior de la cuba, que puede asi volver a utilizarse. La cuba actualmente utilizada, que es de inconel, tiene una seccion de 20 cm de diametro y una altura de 1 m. Se han estudiado los siguientes aspectos: composicion de la mezcla; caudal de alimentacion optimo; posibilidad de efectuar una alimentacion separada de la solucion activa y del vidrio sinterizado, sin mezcla previa; y condiciones de la colada del vidrio. Se esta construyendo una instalacion formada por una cuba de 2 m de altura y de unos 20 cm de diametro, calentada por induccion. (author) [Russian] Osteklovyvanie v tigljah daet nekotorye preimushhestva blagodarja prostote v jekspluatacii i neznachitel'nym poterjam radioaktivnosti pri obzhige. Dlja proizvodstvennyh ustanovok jeti poteri javljajutsja bol'shimi, krome jetogo uvelichivaetsja ob'em othodov, prednaznachennyh dlja hranenija. Byli razrabotany dva metoda osteklovyvanija, obespechivajushhie proizvodstvo pri prostejshem oborudovanii. Odin javljaetsja nepreryvnym processom, a drugoj predstavljaet soboj polunepreryvnoe osteklovyvanie ''v tigle''. Jeksperimental'naja ustanovka nepreryvnogo osteklovyvanija imeet proizvoditel'nost' okolo 100 l rastvora v den'. Ona sostoit iz vrashhajushhegosja kal'cinatora, soedinennogo s plavil'noj pech'ju nepreryvnogo dejstvija v vide zharoprochnogo tiglja s jelektricheskim nagrevom. Jetot zharostojkij tigel

  1. Flute Characteristics of and Microwave Emission from a Plasma in a Mirror; Instabilite en Cannelures et Emission de Micro-Ondes par un Plasma dans une Machine a Miroirs; Zhelobkovye kharakteristiki i ehmissiya mikrovoln iz plazmy v zerkale; Caracteristicas del Estriado y Emision de Microondas por un Plasma en un Espejo

    Scott, F. R.; Jensen, T. H.; Wharton, C. B. [General Atomic Division, General Dynamics Corporation, San Diego, CA (United States)

    1966-04-15

    , intensa e irregular emision de microondas y rapida disminucion de la densidad. Se identifica en la memoria la estrfa de m = 1 y se sigue su fase hasta abarcar 4{pi}. La velocidad de fase coincide con la direccion de la deriva B de los electrones. El signo de esta velocidad de fase puede explicarse mediante la teorfa de Krall si la energfa de los electrones es mucho mayor que la energfa de los iones. El agregado de placas conductoras despues del espejo, atempero la violencia de la inestabilidad en forma de.estrias. Esta atenuacion solo depende de la resistencia superficial de dichas placas. El efecto se estudio midiendo el espectro de frecuencias de las sefiales provenientes de sondas de centelleo provistas de revestimiento y colocadas en la proximidad del recipiente de vacfo. (author) [Russian] Postroen impul'snyj probkotron dlja issledovanija ustojchivosti plazmy s umerennoj jenergiej. Plazma s jenergiej 70 jev inzhektiruetsja iz plazmennoj pushki v probkotron s pomoshh'ju linejnogo vos'mipoljusnogo napravljajushhego polja. Probochnoe pole sozdaetsja v moment prohozhdenija plazmy. V central'noj ploskosti probkotrona nabljudajutsja plotnosti plazmy 10{sup 13} jelektronov cm{sup -3}. Nabljudajutsja dva razlichnyh rezhima raboty, kotorye zavisjat tol'ko ot uslovij, sozdannyh v napravljajushhem pole. Pri pervom rezhime raboty plazma v probko- trone, po-vidimomu, javljaetsja ustojchivoj k zhelobkam, bol'shaja chast' plazmy uhodit vdol' osi, nabljudaetsja medlennaja anomal'naja radial'naja diffuzija i voznikaet mikrovolnovoe izluchenie na jelektronno-ciklotronnyh garmonikah v diapazone ot p = 1 i po krajnej mere do p = 19. Mikrovolnovoe izluchenie ne soglasuetsja s jelektronnoj vetv'ju neustojchivosti Garrisa. Schitaetsja, chto ustojchivost' jetogo tipa vyzvana provodimost'ju za schet holodnoj plazmy, istekajushhej iz oblasti napravljajushhego polja. Nabljudajutsja plotnosti svyshe 10{sup 11} jelektronov cm{sup -3} v techenie 200 mksek v oblasti mezhdu probkoj i

  2. Electronic Modification of the Scintigram and its Limitations; Modification Electronique des Scintigrammes: Limitations; Ehlektronnoe usovershenstvovanie stsintigrammy i ego ogranicheniya; Modificacion Electronica de los Centelleogramas: Sus Limitaciones

    Conrad, B.; Horst, W. [University Clinic for Radiotherapy and Nuclear Medicine Cantonal Hospital, Zurich (Switzerland)

    1964-10-15

    sobljudat' nekotorye o s novnye zakonomernosti dlja togo, chtoby poluchit' maksimum informacii. Jeti zak on om ernosti razrabotany pri ispol'zovanii sledujushhih parametrov i funkcij, kotorye v celom harakterizujut transformirujushhie sistemy vseh vidov: 1. Jelementarnaja jachejka pervichnoj informacii, opredelja em aja intervalami vremeni ili predvaritel'no otobrannym chislom o tschetov, it.d. 2. Funkcija preobrazovanija informacii, v sootvetstvii s kotoroj jelementarnaja jachejka . predstavljaetsja na scintigramme (naprimer, stepen'ju potemnenija fotopjatna). Chasto jet a funkcija r a ssmatri v aet sja kak okonchatel'naja harakteristika transformirujushhej sistemy; odnako jet o spravedlivo tol'ko pri neznachitel'nyh statisticheskih kolebanijah. 4 Povedenie transformirujushhej si st emy , vkljuchaja st atisticheskie kolebanija, opisyvaetsja sledujushhimi funkcijami, kotorye pokazyvajut kachestvo scintigrammy s kolichestvennoj tochki zrenija. 3. Funkcija generacii snimka, v sootvetstvii s kotoroj srednjaja velichina skorosti scheta v zon e transformiruetsja v sredne e potemnenie sootvetstvujushhej zony na scintig ramme. Jeta funkcija da et kontrastnoe usi lenie. 4. Funkcija dostovernosti, kotoraja opisyvaet poterju informacii, prichinennuju transformaciej. Jeta funkcija da et stepen' pravil'nosti vosproizvedenija izobrazhenija. Na osnove vysheukazannyh opredelenij v doklade rassmatrivajutsja sledujushhie problemy: optimal'nyj ''razmer'' jachejki pervichnoj informacii v zavisimosti ot razreshajushhej sposobnosti detektora; optimal'naja forma transformirujushhej funkcii dlja razlichnyh celej; nekotorye jelektronnye kontury dlja realizacii takih funkcij. V chastnosti budet podrobno opisan pribor, kotoryj daet optimal'noe znachenie linejn ogo predstavlenija pri ispol'zovanii sootvetstvujushhim obra zom podobrannoj nelinejnoj transformirujushhej funkcii. Takim obrazom, interval chistoj skorosti scheta v promezhutke mezhdu fonovoj i maksimal'noj skorost'ju scheta proeciruetsja

  3. Reactor Physics Development for Advanced Gas-Cooled Reactors; Recherches en Physique des Reacteurs, pour des Reacteurs Perfectionnes Refroidis par un Gaz; Razrabotka metodov v oblasti reaktornoj fiziki dlya usovershenstvovannogo reaktora s gazovym okhlazhdeniem; Progresos de la Fisica de los Reactores de Tipo Avanzado Refrigerados por Gas

    Moore, J. [United Kingdom Atomic Energy Authority (United Kingdom)

    1964-04-15

    metodos de medicion de los efectos de la reactividad en APEX, HERO y AGR, y para determinar los datos relativos a la estructura fina y a la distribucion de la potencia en los conjuntos combustibles complejos. Los trabajos se concentran principalmente en el desarrollo de un metodo capaz de sustituir al 'hetrecontrol' y al 'FTD2' , para los cuerpos de reactor cuando el combustible haya alcanzado un grado de combustion considerable. La finalidad del programa experimental con la instalacion HERO es precisamente comprobar estos metodos con cuerpos complejos, inclusive con combustible que contenga plutonio. La explotacion del reactor AGR y las mediciones fisicas que se realicen con el combustible despues de la irradiacion permitiran obtener datos adicionales sobre el efecto del plutonio. (author) [Russian] Rassmatrivaetsja tshhatel'naja jeksperimental'naja i teoreticheskaja rabota, provedennaja pri konstruirovanii, stroitel'stve i vvode v jekspluataciju Uindskejlskogo usovershenstvovannogo reaktora s gazovym ohlazhdeniem i pri okazanii obshhej pomoshhi pri razrabotke usovershenstvovannogo reaktora s gazovym ohlazhdeniem (AGR) dla proizvodstva jenergii dlja grazhdanskih celej. Daetsja opisanie znachitel'nogo ob{sup e}ma rabot, kotorye byli neobhodimy dlja razrabotki prigodnyh teoreticheskih metodov rascheta: 1) raspredelenija potoka i balansa reaktivnosti v slozhnoj aktivnoj zone reaktora; 2) raspredelenija jenergii v toplive so slozhnoj geometriej i 3) vlijanija obluchenija na toplivnye cikly i raspredelenie jenergii. V kachestve vvedenija delaetsja ssylka na jeksperimental'nye dannye i teoreticheskie metody, poluchennye v rezul'tate rabot nad uranovo-magnoksovymi sistemami, i na jeksperimental'nye dannye, poluchennye v rezul'tate Sovmestnoj jeksperimental'noj programmy Britanskoj promyshlennosti (BICEP), kotorye javilis' otpravnym momentom v razrabotke teoreticheskih metodov, primenimyh k usovershenstvovannym reaktoram s gazovym ohlazhdeniem. Dlja opredelenija parametrov

  4. Assessment of Tritium in Production Workers; Charge Corporelle de Tritium dans les Usines de Production de ce Radioelement; 041e 041f 0420 0415 0414 ; Evaluacion del Tritio en el Personal Dedicado a la Produccion de Este Isotopo

    Butler, F. E. [Savannah River Plant, E. I. Dupont de Nemours and Company, Aiken, SC (United States)

    1964-11-15

    dlja podscheta i otdelenija interferirujushhih radioizotopov. Summirujutsja dannye jempiricheskogo issledovanija perioda poluvyvedenija v 310 sluchajah, gde nachal'naja,koncentracija4tritija,v moche sostavljala ot 20 do 118 mkkjuri/l, a srednij period poluvyvedenija ravnjalsja 9,5 dnjam. Period poluvyvedenija byl obratno proporcionalen temperature okruzhajushhej sredy i vozrastu rabotajushhih. (author)

  5. Electron and Proton Transfer by the Grotthuss Mechanism in Aqueous Solution and in Biological Systems; Transfert d'Electrons et de Protons par le Mecanisme de Grotthuss en Solution Aqueuse et dans les Systemes Biologiques; Perenos ehlektronov i protonov mekhanizmom grotkhusa v vodnom rastvore i v biologicheskikh sistemakh; Transferencia Electronica y Protonica por el Mecanismo de Grotthuss en Soluciones Acuosas y en Sistemas Biologicos

    Horne, R. A.; Courant, R. A.; Johnson, D. S. [Arthur D. Little, Inc. Cambridge, MA (United States)

    1965-10-15

    jelektronnogo Fe{sup II} - Fe{sup III} i nekotorye dolgovremennye biologicheskie reakcii okislenija-vosstanovlenija svjazany s perenosom jelek- tronov mehanizmom tipa Grothusa cherez vodjanye mostiki. Mehanizm Grothusa javljaetsja takzhe prichinoj anomal'no bol'shoj jelektroprovodnosti kislotnyh vodnyh rastvorov. Pri obychnyh davlenijah stupen'ju, opredeljajushhej skorost' mehanizma Grothusa, javljaetsja vrashhe- nie N{sub 2}O ili, vozmozhno N{sub 3}O+ , a ne dejstvitel'naja orientacija protonov. Mehanizm Grothusa ogranichivaetsja 'svobodnoj' vrashhajushhejsja monometricheskoj vodoj mezhdu skoplenijami Frank- Vena v zhidkoj vode i izbegaet oblastej otnositel'nogo porjadka. Zavisimost' protonnoj provodimosti ot koncentracii mozhet byt' predstavlena uravneniem, osnovannym na kubicheskom korne jekstrapoljacii koncentracii i soderzhashhim uslovija Arheniusa, pri kotoryh jenergii aktivacii javljajutsja jenergijami dlja vrashhenija i obrazovanija 'otverstij' v rastvorjajushhej vode. Takim obrazom, himicheskuju i jelektricheskuju jenergiju mozhno bystro peredavat' na sravnitel'no bol'shie rasstojanija s pomoshh'ju mehanizma Grothusa. Takie processy svjazany s rjadom javlenij, predstavljajushhih interes dlja biologii, primerami kotoryh javljajutsja myshechnoe sokrashhenie i himija dyhatel'nyh pigmentov. (author)

  6. Scanning of Bone Marrow in Haematopoietic Disorders; Gammagraphie de la Moelle Osseuse dans les Troubles Hematopoietiques; Skennirovanie kostnogo mozga pri gematopoehticheskikh narusheniyakh; Exploracion de la Medula Osea en Casos de Trastornos Hematopoyeticos

    Kniseley, R. M.; Andrews, G. A.; Edwards, C. L.; Tanida, R. [Oak Ridge Institute of Nuclear Studies, TN (United States)

    1964-10-15

    individualmente las costillas. Cuando la medula esta dilatada se puede visualizar la zona de la rodilla, incluido el espacio articular. Los autores han logrado establecer una correlacion entre estos centelleogramas, los resultados de biopsias por aspiracion y centelleogramas lineales. Como se requieren dosis relativamente elevadas de oro-198, se esta estudiando la posibilidad de emplear otros isotopos. Tambien se esta ensayando un antropogammametro perfeccionado con el fin de facilitar la exploracion. (author) [Russian] Skennirovanie mozhet pomoch' pri ocenke ob{sup e}ma i raspredelenija gematopojeticheskogo kost- nogo mozga -trudnoj zadache dlja aspiracii ili biopsii. S pomoshh'ju skennera s zolotym- vol'framovym fokusirujushhim kollimatorom diametrom 61 mm v Okridzhskoj nacional'noj laboratorii posle vnutrivennogo vvedenija kolloidal'nogo zolota-198 byli polucheny chetkie ochertanija kostnogo mozga, prichem izvestno, chto retikulo-jendotelial'naja funkcija kostnogo mozga sootvetstvuet oblastjam gematopojeza. Skennirovanie provodilos' u pacientov s normal'nym gematopojezom i s raznymi narushenijami krovi, naprimer s ochagovym porazheniem kostnogo mozga, ostroj i hronicheskoj lejkemiej, istinnoj policitemiej, mielofibrozom, mnozhestvennoj mijelomoj i limfomoj. V svjazi s retikulojendotelial'noj aktivnost'ju v pecheni i selezenke izobrazhenie kostnogo mozga zatemneno v central'nom otdele. Ochercheny tela pozvonkov, mezhpozvonochnye diski, kosti taza i dlinnye kosti, a v grudnoj kletke grudina i grudnye pozvonki. Obnaruzheny takzhe ochagovye porazhenija. Otdel'nye rebra ne vidny iz-za dyhatel'nyh dvizhenij. Pri razrastanii kostnogo mozga ego mozhno videt' v kolennoj oblasti, vkljuchaja oblast' sustava . Pojavilas' vozmozhnost' svjazat' jeti skenogrammy s dannymi aspiracionnoj biopsii i s linejnymi diagrammami. V svjazi s tem, chto trebujutsja sravnitel'no bol'shie dozy zolota-198, issleduetsja vozmozhnost' primenenija drugih izotopov. Dlja poluchenija skennogramm, imejushhih bol

  7. Economics of Grain Irradiation; Aspects Economiques de l'Irradiation du Grain; Ehkonomika oblucheniya zerna; Aspectos Ecomomicos de la Irradiacion de Granos

    Baines, B. D. [Nuclear Chemical Plant Ltd. (United Kingdom); Mosely, J. [Radiation Dynamics Ltd., London (United Kingdom)

    1966-11-15

    industriels pour s'assurer qu'elles sont acceptables pour les utilisateurs eventuels. Les methodes sont en outre expliquees, afin que l'on puisse les appliquer a des problemes analogues. (author) [Spanish] Despues de tres anos de estudios preparatorios se ha proyectado una instalacion de irradiacion de granos que se esta montando en un silo ya en uso. Sobre la base de la experiencia adquirida se calcula el costo real de construccion de una instalacion que utilice cobalto-60; dicha experiencia se aprovecha asimismo para calcular el costo de instalaciones destinadas a tratar grandes cantidades de grano. Se comparan los costos correspondientes a dos tipos de instalaciones de complejidad semejante; por este procedimiento se determina en que regiones resulta mas apropiado cada uno de ellos y en cuales cualquiera de los dos puede ser el mas indicado, segun las condiciones de emplazamiento, el nivel tecnologico local y los metodos de explotacion. Estos dos tipos de instalacion se describen con suficiente detalle para que se puedan apreciar claramente los elementos de equipo que corresponden a los costos indicados. Los metodos de contabilidad se han discutido con contables industriales a fin de tener la seguridad de que son aceptables para los posibles usuarios. Se explican los metodos seguidos para que puedan aplicarse a problemas analogos. (author) [Russian] Spustja tri goda, v techenie kotoryh byli podgotovleny jeskiznye proekty, byla skonstruirovana ustanovka po oblucheniju zerna, kotoraja v nastojashhee vremja ustanavlivaetsja v sushhestvujushhuju ustanovku po silosovaniju. Na osnove jetogo opyta v nastojashhee vremja izvestna dejstvitel'naja stoimost' sooruzhenija predprijatija, ispol'zujushhego ustanovku kobal't-60; jetot opyt vkljuchaetsja v smetu na ustanovku mashin po obrabotke zerna vysokoj propusknoj sposobnosti. Privoditsja sravnenie stoimosti dlja predprijatij sravnimoj slozhnosti i ona opredeljaet te oblasti, v kotoryh kazhdyj vid predprijatija javljaetsja naibolee

  8. Critical Consideration of the Methods of Calculation Used in the Evaluation of the Absorbed Dose to the Skin in Cases of External Contamination; Observations Critiques sur les Methodes de Calcul Utilisees pour l'Evaluacion de la Dose Absorbee par la Peau en Cas de Contamination Externe; 041a 0420 0414 ; Observaciones Criticas Sobre los Metodos de Calculo Utilizados para Evaluar la Dosis Absorbida por la Piel en Caso de Contaminacion Externa

    Casnati, E.; Breuer, F. [Gruppo di Dosimetria e Standardizzazione, CNEN, Centro di Studi Nucleari della Casaccia, Rome (Italy)

    1965-06-15

    resultats permettent de conclure que, dans la geometrie consideree, on peut determiner par des formules de type exponentielle, d'une part la dose imputable aux rayons beta et, d'autre part, la dose imputable aux rayons gamma pour la couche basale de la peau;- on peut considerer les resultats comme acceptables du point de vue de la radioprotection. (author) [Spanish] La dosis absorbida, suele calcularse mediante la formula de Loevinger cuando se trate de particulas beta mientras que para las radiaciones electromagneticas se recurre habitualmente a una formula exponencial. En la memoria, los autores se proponen examinar si en el caso de contaminacion cutanea puede considerarse satisfactorio el empleo de una formula exponencial (la formula de Rossi y Ellis) y de una formula similar para calcular la dosis beta y la dosis gamma, respectivamente. Con este objeto, se han comparado los resultados.obtenidos para este tipo especial de geometria por medio de la formula de Rossi y Ellis y con la formula de Loevinger para partfculas beta; por lo que respecta a la radiacion gamma, se han comparado los valores obtenidos mediante la formula exponencial y con otras dos formulas mas complejas, que se ajustan a las condiciones de acumulacion fotonica maxima nula, respectivamente. Estos resultados permiten sacar la conclusion de que, dadas las condiciones geometricas de que se trata, pueden determinarse mediante la formula de tipo exponencial tanto la dosis de radiacion beta como la dosis de radiacion gamma en la dermis. Los resultados son aceptables desde el punto de vista de la proteccion radiologica. (author) [Russian] Obychno pri podschete dozy ispol'zuetsja formula Laevingera dlja chastic i jeksponencial'naja formula dlja jelektromagnitnyh izluchenij. V doklade rassmatrivaetsja vopros o tom, mozhno li schitat' udovletvoritel'nym ispol'zovanie jeksponencial'noj formuly (podobnoj formule Rossi i Jellisa) i analogichnyh formul pri podschete sootvetstvenno beta- i gamma-dozy. S jetoj cel

  9. Optimization of Gamma-Ray Counting and Spectrometry in Biomedical Tracer Studies; Optimisation du Comptage et de la Spectrometrie des Rayons Gamma dans des Etudes Biomedicales Faites a l'Aide de Traceurs; Optimizatsiya gamma-scheta i spektrometrii gamma-luchej v biomeditsinskikh issledovaniyakh s pomoshch'yu indikatorov; Optimizacion del Recuento y de la Espectrometry Gamma en los Estudios Biomedicos con Indicadores

    Guinn, V. P. [General Dynamics Corporation, San Diego, CA (United States)

    1965-10-15

    rezul'taty jetih raschetov opti- mizacii otschityvanija imejut dvojnuju pol'zu. V osnovu raschetov byli polozheny prostye gipotezy, osnovannye prakticheskih bio- medicinskih soobrazhenijah: 1) malyj razmer prob (ne bolee 10 ml); 2) ogranichennoe vremja' otschityvanija (ne bolee 20 min); 3) nebol'shie dopustimye periody raspada (ne bolee treh sutok) i 4) ispol'zovanie imejushhegosja v prodazhe oborudovanija dlja otscheta i zashhity. Na jetoj osnove byli opredeleny naibolee chuvstvitel'nye metody otscheta dlja kazhdogo iz vysheupomjanutyh radioizotopov, a takzhe dlja ih par i troek. Uchityvalis' sledujushhie peremennye velichiny otscheta: 1) tip kristalla NaJ (T1), a imenno cel'nyj ili s kanalom, 2) razmer kristalla NaJ (T1)-do5h 5 djujmov i 3) tip izmeritel'nyh priborov: prostaja pereschetnaja shema, odnokanal'nyj i mnogokanal'nyj analizator amplitudy impul'sov. Dlja kazhdogo optimal'nogo uslovija otscheta podschitany minimal'naja ulovimaja udel'naja aktivnost' proby, a takzhe urovni ee, neobhodimye dlja sobljudenija statisticheskoj pra- vil'nosti (vyrazhennoj v vide standartnyh otklonenij) v predelah {+-}20, {+-}10, {+-}5 i {+-}2% . Dlja celogo rjada pokazatel'nyh sluchaev raschetnye predely byli sopostavleny s jeksperi- mental'nymi. Osoboe vnimanie udeljalos' nailuchshim uslovijam ponizhenija do minimuma doli izluchaemyh svincom rentgenovskih luchej, obratnogo rassejanija gamma-luchej, pikov utechki, chisla beta-chastic v probe i tormoznogo izluchenija. (author)

  10. Characteristics of the Beam-Plasma Discharge; Caracteristiques de la 'Decharge Faisceau-Plasma'; ХАРАКТЕРИСТИКИ РАЗРЯДА ПУЧКА В ПЛАЗМЕ; Caracteristicas de la Descarga Haz-Plasma

    Smullin, L. D.; Getty, W. D. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1966-04-15

    annotacii my podvodim itog nedavnej raboty po izucheniju vzaimodejstvija jelektronnogo puchka s plazmoj, prodelannoj v Massachuzetskom tehnologicheskom institute. Kogda jelektronnyj puchok prohodit cherez plazmu, on vozbuzhdaet kolebanija na plazmennoj chastote. Jeti mikrovolnovye kolebanija podderzhivajut mikrovolnovyj razrjad, i my nazvali ves' process ''puchkovym razrjadom'. Ionizacija okruzhajushhego gaza osushhestvljaetsja jelektronami vysokoj jEhnergii iz plazmy, kotorye uskorjajutsja poljami kolebanij. Rezul'tatom javljaetsja obrazovanie gorjachej jelektronnoj plazmy vnutri ustanovki s magnitnymi probkami. Poskol'ku parametry razrjada puchka v plazme predstavljajutsja neblagoprijatnymi dlja neposredstvennogo ionnogo nagreva vzaimodejstviem puchka s plazmoj, my pristupili k jeksperimentam, v kotoryh dopolnitel'naja radiochastotnaja jenergija nakladyvaetsja s cel'ju vozbuzhdenija ciklotronnyh kolebanij ionov dlja ionnogo nagreva. Rassmotreniju podlezhat ustojchivost' plazmy; plotnost', srednjaja jenergija i maksimal'naja jenergija jelektronov plazmy; i predvaritel'nye rezul'taty po ionnomu nagrevu. Provodjatsja jeksperimenty s pul'sirujushhim jelektronnym puchkom v 10-15 kv i 10 - 15 A, kotoryj inzhektiruetsja vdol' osi magnitnyh probok v'oblast' drejfa, soderzhashhuju H{sub 2} np 10{sup -5}-10{sup -4} torr. Plotnost' jelektronov plazmy ob{sup e}mom v 1 litr obychno sostavljaet 10{sup 12}-10{sup 13} sm{sup -3} i plotnost' poperechnoj jEhnergii obychno sostavljaet 10{sup 15} jev/sm{sup 3}, chto sootvetstvuet temperature poperechnyh jelektronov v 10{sup 2}-10{sup 3} jev. Izmerenie jenergij rentgenovskih luchej ukazyvaet na sushhestvovanie' jelektronov s jenergiej 50-100 kjev. Spad plazmy posle vykljuchenija puchka proishodit v dva jetapa: otnositel'no bystraja poterja jelektronov nizkoj jEhnergii, {tau} Less-Than-Or-Equal-To 1000 mksek, i medlennyj spad jelektronov vysokoj jEhnergii s {tau} = 10-50 msek. Vtoroj jeksperiment provoditsja s temi zhe parametrami

  11. Drift Instabilities and Electron Cyclotron Oscillations for Arbitrary Plasma Pressure; Instabilites de Derive et Oscillations Cyclotroniques des Electrons pour des Pressions de Plasma Arbitraires; Drejfovaya neustojchivost' i ehlektronno-tsiklotronnye kolebaniya pri proizvol'nom davlenii plazmy; Inestabilidades de Deriva y Oscilaciones Ciclotronicas de los Electrones en un Plasma de Presion Arbitraria

    Krall, N. A.; Pearlstein, L. D. [General Atomic Division, General Dynamics Corporation, San Diego, CA (United States)

    1966-04-15

    radiar si estan acoplados a ondas transversales; con {beta} = 0 este acoplamiento se producan la superficie o en una inhbmogeneidad local. Puesto que un efecto notable de {beta} finito es el de acoplar ondas longitudinales y transversales, los autores calculan el espectro y el acoplamiento de oscilaciones ciclotronicas de los electrones para valores de {beta} arbitrarios. (author) [Russian] Bol'shaja chast' izvestnyh drejfovyh neustoj- chivostej {l_brace}zhelobkovaja, universal'naja i t . d . ) byla rasschitana v predele {beta} = (plazmennoe dav- lenie)/(magnitnoe davlenie)= 0. V jetom predele vozmushhennoe jelektricheskoe pole javljaetsja jelektrostaticheskim i uravnenie Vlasova maksimal'no uproshheno.- Predel'noe {beta}, pri kotorom eshhe spravedlivo jelektrostaticheskoe priblizhenie, zavisit ot rassmatrivaemoj formuly kolebanij, i mnogie sovremennye jeksperimenty vyhodjat za jetot diapazon. Dva horosho izvestnyh nizkochastotnyh vida drejfovyh neustojchivostej issledujutsja pri proizvol'nom {beta}; opredeljaetsja rezhim nulevogo {beta}, i vyvodjatsja kriteriiustojchivosti dlja bol'shih znachenij {beta}. Krome togo, issleduetsja vlijanie konechnogo {beta} na izuchenie na jelektronno-ciklotronnoj garmonike. Vnachale rassmatrivaetsja zhelobkovaja neustojchivost' s konechnym larmorovskim radiusom (R), vyzyvaemaja kriviznoj magnitnogo polja zerkal. Pugajushhie bol'shie chleny samyh nizkih porjadkov, obratno proporcional'nye R{sup 2}, sokrashhajutsja vo vseh porjadkah po {beta}. Glavnye chleny zatem ne zavisjat ot R i vkljuchajutsja v zadachu o sobstvennyh znachenijah; poluchajutsja kriterii ustojchivosti dlja razlichnyh diapazonov {beta}. Dalee rassmatrivaetsja universal'naja neustojchivost' E (vozmushhennoe) = E(exp ik{sub Up-Tack }r{sub Up-Tack })(exp ik{sub II}r{sub II}) v odnorodnom magnitnom'pole B = B{sub 0}i{sub II} s kriviznoj polja, imitirovannoj fiktivnoj siloj tjazhesti. V jetom sluchae predel nulevogo {beta} zavisit ot dliny voln.' Esli {beta}<(massa jelektrona

  12. Measurements of Caesium-137 in Finnish Lapps in 1962-1964 by a Mobile Whole-Body Counter; Dosages de Cesium 137 chez les Lapons de Finlande en 1962-1964, au Moyen d'un Anthro- Pogammametre Mobile; 0418 0417 041c 0415 0420 0414 ; Determinacion del Cesio-137 en Lapones Finlandeses, en 1962-1964, Mediante un Antropogammametro Movil

    Miettinen, J. K. [Department of Radiochemistry, University of Helsinki (Finland)

    1964-11-15

    ), kristall NaJ(Tl ) (12,5 h 7,5 sm) zashhishhen vo vseh napravlenijah, krome kamery, sloem svinca tolshhinoj 8sm. Oborudovanie sostoit iz 512-kanal'nogo analizatora, kopiroval'nogo apparata, h,u-registratora i stabilizatora, kotorye vo vremja transportirovki pomeshhajutsja v protivoudarnye i pylenepronicaemye jashhiki. Gruzovik snabzhen termostaticheskoj obogrevatel'noj sistemoj i soderzhit dva sanitarnyh otseka. Kalibrovka sistemy proizvodilas' po ceziju-137 dvumja sposobami: 1. Putem dachi vnutr' razlichnym obsleduemym tochno izvestnogo kolichestva (200 - ZOOmmkkjuri) cezija-137 i po'sledujushhego opredelenija jeffektivnosti scheta v techenie 3 - 6 dnej. Vydeljajushhijsja cezij-137 opredeljali ,-pu tem sbora i analiza mochi i jekskrementov. 2. Putem podscheta na plastmassovom fantome, zapolnennom 70 kg rastvora, soderzhashhego 1552 mmkkjuri cezija-137. Jeffektivnost' pervogo metoda na 4,6% vyshe vtorogo. Byla prinjata jeffektivnost' pervogo metoda, kak naibolee pravil'naja. Jeto bylo provereno s pomoshh'ju trojnoj vzaimnoj kalibrovki s dvumja drugimi laboratorijami dlja opredelenija radioaktivnosti vsego organizma. Polucheno horoshee sootvetstvie (v predelah 1-4%). Dlja kalija predvaritel't naja kalibrovka proizvodilas' s pomoshh'ju fantoma. Jeffektivnost' sostavljala 2,51 otsch /min/mmkkjuri Cs{sup 137} (0,60 - 0,72 Mjev, 20 kanalov) i 0,145 otsch/min/g kalija (1,38 - 1,55 Mjev, 30 kanalov). Kogda gruzovik ustanovlen na skale, sootvetstvujushhie velichiny scheta fona na fantome vesom 70 kg (sahar) sostavljajut 77 otsch/min i 58 otsch/min sootvetstvenno. Na peschanoj pochve fon sostavljaet polovinu jetoj velichiny. S pomoshh'ju jetogo peredvizhnogo schetchika byli provedeny tri polevyh obsledovanija v finskoj Laplandii. V mae 1962 goda byli obsledovany 218 loparej, statisticheski predstavljajushhih gruppy iz treh okrugov finskoj Laplandii, Inari, Karesuanto i Utsioki. Pri jetom proizvodilis' dijeticheskie i medicinskie issledrvanija. V sentjabre 1962 goda i marte 1963 goda

  13. Study on the Localization of Iodine in the Stomach; Etude de la Localisation de l'Iode dans l'Estomac; Izuchenie lokalizatsii joda v zheludke; Estudio de la Localizacion del Yodo en el Estomago

    Clode, W. H.; Perez Fernandez, M. A.; Baptista, A. M. [Comissao de Estudos de Energia Nuclear do Instituto de Alta Cultura, Lisbon (Portugal); Simao Rodrigues, M.; Murteira, M. A. [Instituto Portugues de Oncologia, Lisbon (Portugal)

    1964-10-15

    estudios los autores han llegado a la conclusion de que ciertas regiones del estomago normal desempefian un papel importante en el metabolismo del yodo. La localizacion de las zonas en que la concentracion de radiactividad es mas elevada indica que la excrecion de yodo puede ser regida por varios mecanismos. Estas observaciones corroboran los resultados obtenidos por otros investigadores con metodos diferentes. La exploracion efectuada 24 h despues de administrar {sup 131}I permitio detectar el cancer del estomago en la mayorla de los pacientes afectados por esa enfermedad. Estos resultados se explican no solo por el hecho de que el yodo se concentra en las celulas tumorales sino tambien porque las paredes del estomago retienen cierta cantidad de este elemento. En la mayor parte de los casos, la concentracion de yodo radiactivo en el tumor no fue superior a la observada en aquellas regiones de la mucosa gastrica en que se produce una absorcion incrementada de este elemento. (author) [Russian] Avtory izuchali lokalizaciju joda v zheludke posle vnutrivennoj in{sup e}kcii iodida, mechennogo jodom-131, ispol'zuja dlja jetogo vysokokontrastnuju sistemu fotoskennirovanija. Issledovanie provodilos' cherez razlichnye promezhutki vremeni posle in{sup e}kcii (obychno cherez 2, 24 i 48 chasov) u bol'nyh, ne stradajushhih nikakimi zheludochnymi zabolevanijami, bol'nyh s rakom zheludka i bol'nyh s pepticheskoj jazvoj. Izuchalos' takzhe raspredelenie radioaktivnogo joda v zheludkah sobaki i cheloveka, udalennyh hirurgicheskim putem v razlichnoe vremja posle in{sup e}kcii radioaktivnogo joda. V udalennyh hirurgicheskim putem zheludkah dlja ob{sup j}asnenija poluchennyh dannyh opredeljalas' udel'naja aktivnost' tkanej, otnosjashhihsja k predstavljajushhim interes oblastjam, obnaruzhen** nym skennirovaniem. Na osnovanii poluchennyh dannyh avtory delajut vyvod, chto v normal'nom zheludke sushhestvujut oblasti, kotorye igrajut osobuju rol' v metabolizme joda. Lokalizacija zon samoj vysokoj

  14. Theory of Pulsed Neutron Experiments in Highly Heterogeneous Multiplying Media; Theorie des Experiences au Moyen des Neutrons Pulses, dans les Milieux Multiplicateurs Tres Heterogenes; O teorii ehksperimentov s impul'snymi neitronami v geterogennykh razmnozhayushchikh sredakh; Aspectos Teoricos de los Experimentos con Neutrones Pulsados en Medios Multiplicadores Muy Heterogeneos

    Corno, S. E. [Instituto di Fisica ' ' A. Volta' ' (Italy); Unversity of Pavia, Pavia (Italy); SNAM, Milan [Italy

    1965-10-15

    priblizhenija otnositel'no jenergeticheskoj zavisimosti opredelennoj populjacii nejtronov. V ramkah vozrastno-diffuzionnoj teorii reakcija pribora na ljuboe vozbuzhdenie nejtronov mozhet imet' zakrytuju formu. Dlja sinusoidal'no modulirovannogo istochnika dannoj chastoty mozhno legko pokazat', chto esli osial'naja singuljarnaja sostavljajushhaja javljaetsja chisto absorbirujushhej, to nejtronnye volny, prohodjashhie cherez pribor, budut obladat' fazoj, dlinoj volny i postojannoj oslablenija, kotorye zavisjat ot absorbirujushhih svojstv singuljarnoj sostavljajushhej. Jeta kartina vse bolee uslozhnjaetsja, kogda proishodit razmnozhenie nejtronov. Dlja dannogo obshhego sluchaja reshenie, kotoroe privoditsja v nashem doklade, ochevidno, javljaetsja zavisimym kak ot absorbirujushhih, tak i ot razmnozhajushhih svojstv singuljarnoj sostavljajushhej. Jeto obstojatel'stvo predpolagaet, pomimo prochego, vozmozhnost' ispol'zovanija pribora vysheukazannogo tipa dlja ispytanija toplivnyh jelementov geterogennyh reaktorov. (author)

  15. Dosimetry of High-Energy Protons by Measurement of Beryllium-7 Formed in the Tissues; Dosimetrie des Protons de Haute Energie par Mesure de Beryllium-7 Forme dans les Tissus; 041e 0422 041d 041e 0421 0414 ; Dosimetria Relativa Mediante Berillo-7 Despues de Irradiar con Protones de Altas Energias (600 Mev Y 3 Gev)

    Legeay, G. [Service Biologique et Veterinaire des Armees, Detache au D.P.S. (France); Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Fontenay-aux-Roses (France); Court, L.; Prat, L [Service de Sante des Armees, Detaches au D.P.S. (France); Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Fontenay-aux-Roses (France); Jeanmaire, L.; Daburon, M. L. [Commissariat a l' Energie Atomique (France); Nucleaires de Fontenay-aux-Roses, Centre d' Etudes [France; De Kerviler, H.; Tardy-Joubert, P. [Service de Protection Contre les Radiations, Centre d' Etudes Nucleaires de Saclay (France)

    1965-06-15

    , izvestnyh na segodnjashnij den'. Sluchajnoe obluchenie cheloveka puchkom protonov mozhet byt' tol'ko lokalizovano. Provedennoe Fov de Burgon'e obluchenie golovy krolikov vesom okolo 2 kg, pokazyvaet, chto obnaruzhennaja v golove aktivnost' po sravneniju s aktivnost'ju v ostal'nom tele sostavljaet porjadka 1,8 {+-} 5. Berillij-7 mozhno obnaruzhit' v pervye dni, nesmotrja na nalichie opredelennoj diffuzii. Pojetomu vozmozhna otnositel'naja dozimetrija, pokazyvajushhaja velichinu dozy, poluchennoj v rezul'tate avarijnogo obluchenija. (author)

  16. Studies on the Influence of Tritium Radiation on Anaerobic Bacteria from the Bovine Rumen; Influence de l'Irradiation par le Tritium sur les Bacteries Anaerobies du Rumen des Bovins; 0418 0441 0414 ; Estudios sobre los Efectos de las Radiaciones del Tritio en las Bacterias Anaerobias de la Panza de los Bovinos

    Brueggemann, J.; Giesecke, D. [Institute of Physiology and Animal Nutrition, University of Munich, Munich, Federal Republic of Germany (Germany)

    1962-02-15

    de los bovinos. Las dosis de hasta 150 krad (cinco dias) no ejercieron un efecto acentuado sobre la proliferacion anaerobia ni sobre el metabolismo de los carbohidratos. En cambio, si la irradiacion de las celulas en reposo se efectua en presencia de oxigeno se observa una notable disminucion del numero de celulas viables. Se ha comprobado que el oxigeno ejerce per se un efecto letal en estas Bullet especies, que decrece logaritmicamente. Se supone que los productos de irradiacion secundarios, sobre todo el H{sub 2}O{sub 2}, son los principales causantes del efecto del T{sub 2}O en estos microorganismos que carecen de catalasa. Los autores esperan obtener algunos resultados confirmatorios. (author) [Russian] Bakterial'naja flora zhvachki krupnogo rogatogo skota sostoit v osnovnom iz chisto anajerobnyh bakterij, kotorye snabzhajut zhivotnoe bol'shim kolichestvom letuchih zhirnyh kislot (LZhK) kak osnovnogo iotochnika jenergii. Dlitel'noe obluchenie flory v laboratornyh uslovijah posred- stvom T{sub 2}O pri tak nazyvaemom 'iskusstvennom perezhevyvanii' v anajerobnyh uslovijah pokazalo, chto dozy do 75 Krad ne imejut sderzhivajushhego vlijanija na rost bakterij i vyrabotku LZhK. Stimuliruemye vozdejstvija, zakanchivavshiesja uskoreniem delenija kletki, i vozrosshie kolichestva LZhK nabljudalis' posle obluchenija nahodjashhejsja v svo- bodnom sostojanii flory pri 0 Degree-Sign C v obshhej doze okolo 30 Krad cherez 20 dnej, no vosproizvodstvo bylo neudovletvoritel'nym vsledstvie geterogennosti veshhestva. Dal'nejshie jeksperimenty osushhestvljalis' na chistyh kul'turah otobrannyh porod bakterij zhvachki. Dozy do 150 Krad (5 dnej) ne okazali zametnogo vli- janija na anajerobnyj rost i metabolizm uglevoda. Odnako, esli pri obluchenii nahodjashhihsja v svobodnom sostojanii kletok prisutstvoval kislorod, otmechalos' znachitel'noe sokrashhenie zhiznesposobnyh kletok. Byl obnaruzhen kislorod, koto- ryj na jetot vid bakterij okazyvaet letal'noe dejstvie, soprovozhdavsheesja

  17. A Procedure for the Determination of Alpha-Emitting Plutonium in Urine Using a Solid-State Counter; Methode de Determination du Plutonium Emetteur Alpha Present dans l'Urine, au Moyen d'un Compteur a Semi-Conducteurs; Metod opredeleniya al'fa-izlucheniya plutoniya v moche s pomoshch'yu poluprovodnikovogo schetchika; Procedimiento para Determinar la Actividad Alfa del Plutonio en la Orina con Ayuda de un Contador de Estado Solido

    Sandalls, F. J.; Morgan, A. [Health Physics and Medical Division, Atomic Energy Research Establishment, Harwell (United Kingdom)

    1964-10-15

    kupferronatom zheleza iz jetogo rastvora i jekstragirujut hloroformom. Posle vyparivanija hloroformom osadok okisljajut, rastvorjajut v soljanoj kislote i jekstragirujut zhelezo di- izopropilovym jefirom. Vodnuju fazu, soderzhashhuju plutonij, vyparivajut i rastvorjajut v kislom sul'fate ammonija, iz kotorogo plutonij osazhdajut jelektroliticheski na nerzhavejushhej stali. Kolichestvennye vosstanovlenija na stadii jelektroliticheskogo osazhdenija dali 84 {+-} 7% Osazhdennyj plutonij podschityvali s pomoshh'ju diodnogo (tverdogo s kremnevym soedineniem) schetchika,sozdannogo dlja jetoj celi. Nizkij estestvennyj fon schetchika jetogo tipa byl jeffektivno snizhen putem podscheta lish' teh al'fa-chastic, kotor''ge imejut jenergiju 4.2 - 5,4 Mjev. Horoshee razreshenie, poluchaemoe s pomoshh'ju tonkogo jelektroosazhdennogo istochnika plutonija3obespechivaet vozmozhnost' ochen' malyh poter' jeffektivnosti scheta v jetom uzkom kanale. Pri schete vne'jetoj ogranichennoj oblasti jenergii kontrol'naja aktivnost', sozdavaemaja reaktivami i nepolnoj ochistkoj ot drugih al'fa-izluchatelej v moche, takzhe snizhaetsja na faktor porjadka 2, nemnogo vyshe 0,01 mkmkkjuri v-techenie 24 chasov. Predel obnaruzhenija s pomoshh'ju jetogo metoda sostavljaet okolo 0,025 mkmkkjuri plutonija-239. (author)

  18. Review of the {sup 60}Co Source. Development Program at Brookhaven National Laboratory; Le Programme de Mise au Point des Sources au {sup 60}Co au Laboratoire National de Brookhaven; Obzor programmy po razrabotke istochnikov {sup 60}Co v brukkhejvenskoj natsional'noj laboratorii; El Programa de Preparacion de Fuentes de {sup 60}Co del Laboratorio Nacional de Brookhaven

    Kuhl, O. A. [Brookhaven National Laboratory, Upton, NY (United States)

    1966-11-15

    jenergii SShA Brukhejvenskaja nacional'naja laboratorija(BNL) pristupila k razrabotke istochnikov izluchenij. Jeti istochniki byli v osnovnom bol'shie trubki i ploskie plastinki. Pervonachal'no oni prednaznachalis' dlja issledovanij v BNL. Pozdnee drugie uchrezhdenija poluchili razreshenie ispol'zovat' obluchateli, prednaznachennye dlja jetih istochnikov. Po mere povyshenija interesa kombinirovannye ustanovki, vkljuchajushhie istochnik i obluchatel', predostavljalis' drugim issledovateljam. Byli razrabotany kontejnery dlja transportirovki istochnikov i skonstruirovany nebol'shie ''gorjachie'' kamery i napolnennye vodoj bassejny dlja ispol'zovanija jetih istochnikov. Obsuzhdajutsja metody dozimetrii, opredelenie radioaktivnosti v kjuri i konstrukcija obluchatelja dlja jetih istochnikov. V bol'shinstve sluchaev vo vremja provedenija issledovanij jekonomicheskie aspekty ne imeli znachenija; odnako v svjazi s tendenciej k krupnomasshtabnoj radiacionnoj obrabotke v obla Inverted-Question-Mark tjax pishhevyh produktov, himikatov i medicinskih materialov neobhodimo budet tshhatel'no izuchit' tehnicheskie i jekonomicheskie aspekty konstrukcii istochnika. Razrabotka standartnyh istochnikov Brukhejvenskoj nacional'noj laboratorii ''Mark I'' i ''Mark I{sup ,} kotorye' uzhe ispol'zujutsja v rjade ustanovok, prizvana udovletvorit' jetim vazhnym trebovanijam. Istochniki ''Mark Ij i 'Mark II' vzaimozamenjaemy. Konstrukcija istochnika 'Mark II' uluchshena za schet metallurgicheskogo soedinenija vnutrennej obolochki s kobal'tovym serdechnikom. V nastojashhee vremja vpervye mozhno povtorno aktivirovat' jeti istochniki posle nekotorogo ispol'zovanija. Otdel'nye polosy dovodjatsja do trebuemyh razmerov s tem, chtoby ih mozhno bylo legko prikrepit' k plastinkam razlichnogo razmera i formy. Opisyvajutsja teoreticheskoe obosnovanie konstrukcii, metody izgotovlenija i procedury ispytanija, a takzhe analiz istochnika i opredelenie radioaktivnosti v kjuri. ''Proizvodjatsja ''sravnenija s drugimi

  19. Treatment, Processing and Future Disposal of Radioactive Wastes at the Idaho Chemical Processing Plant; Traitement et Elimination Future des Dechets Radioactifs a l'Usine de Traitement Chimique de L'Idaho; 0410 041d 0414 ; Tratamiento y Evacuacion de Desechos Radiactivos en la Planta de Tratamiento Quimico de Idaho

    Stevens, James I. [Phillips Petroleum Company, Atomic Energy Division, Idaho Falls (United States)

    1960-07-01

    igrajut bolee znachitel'nuju rol', chem dlja zhidkih tel. Kislotnye othody azotnokislogo aljuminija, poluchajushhiesja pri pererabotke toplivnyh jelementov reaktorov tipa, sluzhashhego dlja ispytanija materialov, mogut byt' prevrashheny v granulirovannye aljuminy putem obzhiganija ih v razzhizhennom sostojanii pri temperature ot 350 do 550 Degree-Sign C. Glavnymi sostavnymi chastjami javljajutsja obzhigatel'naja pech's podogrevom na NaK, sistema ochistki vyhodjashhih gazov i emkosti dlja hranenija othodov v tverdom vide. V dokumente delaetsja opisanie jetoj konstrukcii, proizvodimyh issledovanij i programmy dal'nejshih rabot. V zavisimosti ot uspeha opytnoj ustanovki pechi dlja obzhiganija v razzhizhennom sostojanii i ot uspeha hranenija othodov v tverdom vide pri vysokoj temperature, a takzhe v svjazi i s drugimi soobrazhenijami, v doklade obsuzhdajutsja drugie vozmozhnosti hranenija othodov v budushhem i ih vlijanie na okruzhajushhuju sredu. (author)

  20. Treatment and Processing of Radioactive Wastes; Traitement des Dechets Radioactifs; 041e 0411 0420 0414 ; Tratamiento de Desechos Radiactivos

    Rodger, Walton A. [Chemical Engineering Division, Argonne National Laboratory, Lemont, IL (United States)

    1960-07-01

    fil'trami. Doklad daet opisanie tipichnyh ustanovok. Provodilos' issledovanie po szhiganiju vosplamenjajushhihsja othodov; v doklade daetsja ego opisanie i operativnye dannye. Metod upakovki takzhe igraet vazhnuju rol' v sisteme sbora tverdyh othodov. Byli izucheny razlichnye vidy obrabotki zhidkih othodov. V doklade privoditsja opisanie tipichnyh sistem i prilagajutsja operativnye dannye. Othody s vysokim urovnem radioaktivnosti - Gazy inogda otvodjatsja neposredstvenno v truboprovody, no chashhe vsego trebuetsja nekotoraja predvaritel'naja obrabotka. Obrabotka sostoit iz himicheskoj ochistki, udalenija ioda s poserebrennyh detalej, udalenija inertnogo gaza i fil'tracii. Tverdym veshhestvam s vysokim urovnem zarazhenija mozhet potrebovat'sja dezaktivacija na meste do ih udalenija. Udalenie zhidkih othodov s vysokim urovnem radioaktivnosti predstavljaet soboj samuju slozhnuju problemu, s kotoroj stalkivaetsja v nastojashhee vremja promyshlennost'. Jeta problema vkljuchaet umen'shenie ob{sup e}ma othoda, poluchaemogo pervonachal'no putem izmenenija processa obrabotki; koncentraciju poluchaemogo othoda; ili vosstanovlenie v tverdye pri pomoshhi neskol'kih metodov, vkljuchaja metod koncentracii, ispol'zovanija portland-cementa, adsorbciju na glinah, ili drugih estestvennyh veshhestvah i kal'cinirovanie. V doklade rassmatrivajutsja tehnicheskie i jekonomicheskie problemy, svjazannye s vremennym hraneniem othodov. Obrabotku othodov neobhodimo proizvodit' lish' v tshhatel'no otobrannyh dlja jetoj celi mestah. V doklade privodjatsja podschety priblizitel'nogo kolichestva othodov, kotorye pridetsja transportirovat', i trebuemogo oborudovanija. Rassmatrivajutsja voprosy, svjazannye s riskom i stoimost'ju. (author)

  1. Theoretical Interpretation of Pulsed Neutron Phenomena; Interpretation Theorique des Phenomenes dus aux Neutrons Pulses; Teoreticheskaya interpretatsiya yavlenij, svyazannykh s impul'snymi nejtronami; Interpretacion Teorica de los Fenomenos Debidos a Neutrones Pulsados

    Corngold, N. [Brookhaven National Laboratory, Upton, NY (United States)

    1965-08-15

    . Osoboe vnimanie obrashhaetsja na jeksperiment s impul'snymi nejtronami v nerazmnozhajushhih sredah i na ego interpretaciju s tochki zrenija prostranstvenno-energeticheskih raspredelenij i postojannyh spada (vo vremeni). Teoreticheskie issledovanija v jetoj oblasti, bol'shuju chast' kotoryh provodit Bruk- hejvenskaja nacional'naja la''rratorija, osnovany na tochnom reshenii neskol'kih special'nyh problem, a takzhe na priblizhennyh chislennyh reshenijah v bolee real'nyh situacijah. Ne- davno predlozhena edinaja tochka zrenija, osnovannaja na teorii Van Hov-Glaubera o rassejanii medlennyh nejtronov. Vyjasneno, chto vremennaja zavisimost' parno-korreljacionnoj funk- cii, kotoraja pozvoljaet provodit' raznicu mezhdu razlichnymi zamedliteljami, takzhe regu- liruet obnaruzhivaemyj spektr postojannoj spada. V rabote podcherkivaetsja sluchaj reshenija dlja beskonechnoj sredy, hotorye proporcional'ny jeksponente (iB * r), v sredah s pogloshheniem, podchinennym zakonu 1/v. Analiticheskaja rabota svjazana s naibolee verojatnymi reshenijami, proporcional'nymi takzhe jeksponente ({lambda}t), a chislennyj raschet napravlen na reshenie, uchi- tyvajushhee polnuju ''istoriju processa'', a takzhe na modal'nye reshenija. Zatragivajutsja takzhe javlenija, s kotorymi stalkivalis', kogda pogloshhenie ne podchinjaetsja zakonu 1/v i kogda ob- razec zamedlitelja nastol'ko mal, chto vremennye reshenija ne razdeljajutsja bol'she v pro- stranstvenno energeticheskom otnoshenii. Nakonec, obsuzhdaetsja znachenie jetih rezul'tatov dlja interpretacii impul'snyh jeks- perimentov. V chastnosti, avtory imejut v vidu izmerenie diffuzii, kojefficienty dif- fuzionnogo ohlazhdenija, a takzhe, v zavisimosti ot haraktera podhoda, asimptoticheskoe ras- predelenie . (author)

  2. RBE of some Sodium, Water and Bioelectric Parameters of Gastro-Intestinal Absorption; L'EBR pour le Transport du Sodium et de l'Eau et pour Certains Parametre Bioelectriques dans l'Absorption Gastro-Intestinale; Obeh v otnoshenii nekotorykh natrievykh, vodnykh i bioehlektricheskikh parametrov vsasyvaniya v zheludochno-kishechnom trakte; La EBR Para el Transporte del Sodio y del Agua y Para Ciertos Parametros Bioelectricos en la Absorcion Gastrointestinal

    Vaughan, B. E.; Davis, A. K.; Cummins, J. T.; Alpen, E. L. [US Naval Radiological Defense Laboratory, San Francisco, CA (United States)

    1964-05-15

    permeabilidad decrece al aumentar las dosis de irradiacion. (author) [Russian] Ranee soobshhalos' o biojelektricheskih izmerenijah i izmerenii potoka v odnom napravlenii. Krys i sobak pod- vergali rentgenovskomu oblucheniju pri pikovym naprjazhenii 250 kv (krysy) ili 1000 kv (sobaki) i oblucheniju bystrymi nejtronami. Obluchenie bylo obshhim, dvustoronnim, v kazhdom sluchae proizvodilas' glubinnaja dozimetrija. U hrys cherez 7 dnej posle obluchenija biojelektricheskaja aktivnost' zheludka znachitel'no snizhalas' po sravneniju s normoj, no v nizhnih otdelah zheludochno-kishechnogo trakta takogo snizhenija ne bylo. Dlja pozdnego snizhenija biojelektricheskoj aktivnosti zheludka ustanovlena velichina OBJe porjadka 2-3, jetot jeffekt otchetlivo zameten pri doze nejtronov v 160 rad (1-e stolknovenie). U sobak cherez tri dnja posle obluchenija skorost' odnostoronnego perehoda natrija i vody iz plazmy v prosvet kishechnika snizhalas'. Jeto nabljudaetsja posle rentgenovskogo obluchenija pri 1200 rentgen (doza v vozduhe) i posle nejtronnogo obluchenija pri 300 rad ili 600 rad (1-e stolknovenie). Odnako pri doze rentgenovyh luchej 600 rad (v vozduhe) jeti skorosti perehoda ne izmenjajutsja i imejut drugoe napravlenie. Velichina OBJe dlja pozdnego snizhenija perehoda iz plazmy v prosvet kishechnika budet ravnjat'sja 2 - 6. Izuchenie jelektrogennogo mehanizma na zheludke krysy ukazyvaet na specifichnost' iona natrija v otlichie ot dannyh, poluchennyh na zheludke ljagushki. Velichiny potencialov, poluchennye in vitro, sootvetstvujut velichinam, poluchennym in vivo, i menjajutsja lish' pod vlijaniem metabolicheskogo otravlenija ili zameshhanija natrija. V protivopolozhnost' biojelektricheskim parametram opredelenija potoka javljajutsja bolee specifichnymi; odnako znachitel'naja biologicheskaja variabil'nost' ogranichivaet ih ispol'zovanie. Odnostoronnie toki iz plazmy v prosvet kishechnika obnaruzhivajut znachitel'nye izmenenija pod vlijaniem radiacii, chto ukazyvaet na snizhenie

  3. Assessment of End-Plug Welding of Fuel Elements; Evaluation des Soudures Terminales des Elements Combustibles; Otsenka kachestva privarki kontsevoj probki toplivnykh ehlementov; Inspeccion de la Soldadura del Tapon Terminal de los Elementos Combustibles

    Nakamura, Y.; Aoki, T. [Tokai Refinery, Atomic Fuel Corporation (Japan)

    1965-10-15

    metallicheskogo urana s aljuminievym pokrytiem. Poskol'ku v jelementah mezhdu pokrytiem i serdcevinoj sushhestvuet tol'ko mehanicheskaja svjaz', koncevaja probka mozhet ispytyvat' rastjagivajushhee naprjazhenie v rezul'tate uvelichenija obluchenija uranovoj serdceviny. Tem- peraturnye kolebanija vyzovut analogichnoe naprjazhenie v svarnyh shvah. Vsledstvie neodno- rodnosti mikrostruktury vblizi svarnyh shvov tam mozhet proizojti usilennaja korrozija pod vozdejstviem gorjachej vody. Vo vremja raboty reaktora i posle ego ostanovki neobhodimo obespechit' germetichnost'. Dlja provedenija ispytanij na prochnost' na razryv, ispytanij na polzuchest' pri vysokoj temperature, ispytanij temperaturnyh kolebanij i korrozii byli razrabotany special'- nye obrazcy. Mnogie harakteristiki svarnyh shvov byli izucheny bez razrushenija ispyty- vaemogo obrazca do provedenija ispytanij i provereny na germetichnost' v promezhutkah mezh- du ispytanijami. Jeti rezul'taty mogut byt' ispol'zovany dlja ustanovlenija standartov proverki, takih kak rentgenovskaja radiografija i vizual'naja proverka kachestva privarki koncevoj probki. Budut takzhe opisany nekotorye drugie rezul'taty, poluchennye po topliv- nym jelementam, pokrytym magnoksom ili cirkalloem. (author)

  4. Effects of Monoenergetic Neutron Radiation on Human Cells in Tissue Culture; Effets des Neutrons Monoenergetiques sur des Cellules de Tissus Humains en Culture; Dejstvie oblucheniya monoehnergeticheskimi nejtronami na kletki kul'tury tkanej cheloveka; Efectos de la Radiacion Neutronica Monoenergetica sobre las Celulas Humanas en Cultivos de Tejidos

    Broerse, J. J.; Barendsen, G. W. [Radiobiological Institute of the Organization for Health Research TNO, Rijswijk (Z.H.) (Netherlands)

    1964-03-15

    sharikov, pomeshhennyh sootvetstvenno mezhdu chashkami i trubkami. R a sche t dozy nejtronnogo potoka predstavljal rjad problem, kotorye obsuzhdajutsja. Poskol'ku ne sushhestvuet ravnomernogo obluchenija kletok, izuchajutsja rezul'tirujushhie netochnosti pri opredelenijah dozy. Privodjatsja krivye zavisimosti vyzhivanija ot dozy dlja oboih tipov nejtronov. Dlja nejtronov s jenergiej 3 Mjev otnositel'naja biologicheskaja jeffektivnost' sostavljala ot 6,5 pri malyh dozah do primerno 3,1 pri vysokih d o zah , v to vremja kak dlja nejtronov s jenergiej 15 Mjev velichiny OBJe ko lebalas' ot 1,9 do 1,6. Putem sravnenija jetih velichin OBJe s s o otnosheniem O B Je-LP Je , poluchennym v predydushhih jeksperimentah s dejtronami i al'f a - chasticami, mozhno opredelit' jeffektivnoe LPJe dlja nejtronov, ispol'zovannyh v jeksperimente. Dlja reshenija nekotoryh problem, svjazannyh so smert'ju jeksperimental'nyh zhivotnyh posle rentgenovskogo ili nejtronnogo obluchenija, byl razrabotan metod, s pomoshh'ju kotorogo kletki, soderzhashhiesja v nebol'shih trubkah, ispol'zujutsja dlja izmerenija jeffektivnoj dozy (t.e. dozy, dlja kotoroj vneseny popravki na OBJe) v uchastkah fantomov ili t el zhivotnyh, predstavljajushhih interes. (author)

  5. Radioisotope Scanning of the Pancreas with Selenomethionine-Se{sup 75}; Gammagraphie du Pancreas a l'Aide de la Selenomethionine-{sup 75}Se; Diagnosticheskoe fotoskennirovanie podzheludochnoj zhelezy; Gammagrafia del Pancreas Mediante Radioisotopos

    Sodee, D. B. [Doctors Hospital and Renner Clinic Foundation, Cleveland Heights, OH (United States)

    1964-10-15

    voznikajushhee v rezul'tate koncentraciiselenometionina - {sup 75}Se v pecheni izluchenie, kotoroe v proshlom meshalo tochnomu opredeleniju kontura podzheludochnoj zhelezy. Nedavno avtory ispol'zovali kristall razmerom 12,5 h 7,5 sm i 121-kanal'nyj svincovyj kollimator s fokusnym rasstojaniem 12,5 sm. Jeto uluchshilo kachestvo izobrazhenija, i po mere usovershenstvovanija metodiki mozhno budet, verojatno, videt' men'shie povrezhdenija na bol'shej glubine. Okazalos',chto karcinoma podzheludochnoj zhelezy koncentriruet selenometionina -Se75 . huzhe, chem normal'naja tkan'. S pomoshh'ju jetoj metodiki udalos' pravil'no istolkovat' zabolevanie u 5 iz 6 bol'nyh, stradajushhih karcinomoj podzheludochnoj zhelezy. Nepoddajushhiesja obnaruzheniju Mel'chajshie karcinomatoznye uzly byli zatemneny uvelichennoj pechen'ju. Diagnoz ostrogo i hronicheskogo pankreatita takzhe podtverzhdaetsja skennirovaniem podzheludochnoj zhelezy, poskol'ku povrezhdennye kletki podzheluzhochnoj zhelezy ne koncentrirujut selenometionin -{sup 75}Se. Avtor takzhe opisyvaet izbiratel'noe pogloshhenie selenometionina -{sup 75}Se tkan'ju para- shhitovidnoj zhelezy . S pomoshh'ju jetogo zhe metoda skennirovanija byli obnaruzheny adenomy parashhitovidnoj zhelezy u nebol'shoj gruppy bol'nyh s povyshennoj funkciej parashhitovid- noj zhelezy. Fotoskennirovanie podzheludochnoj zhelezy uzhe javljaetsja prakticheskim metodom, i v nastojashhee vremja vedetsja izuchenie fotoskennirovanija parashhitovidnoj zhelezy. Narjadu s vnov' probudivshimsja interesom k organam, kotorye byli nevidimy pri obychnyh radiograficheskih metodah, selektivnoe skennirovanie organov s pomoshh'ju soedinenij,soderzhashhih mechenye atomy i podobrannyh po ih biohemicheskim svojstvam, stanovitsja vazhnym metodom budushhego. (author)

  6. Recovery of Mice Thymus after X-Rays and 15 MeV Electrons. Comparative Study of the Cell Population Using Tritiated Thymidine; Regeneration du Thymus chez la Souris Apres Irradiation par des Rayons X et des Electrons de 15 MeV. Etude Comparee de la Population Cellulaire a l'Aide de Thymidine Tritiee; 0412 043e 0414 ; Restauracion del Timo de los Ratones Despues de Irradiarlo con Rayos X y Electrones de 15 MeV. Estudio Comparativo de la Poblacion Celular Utilizando Timidina Tritiada

    Biagini, C.; Paleani Vettori, P. G.; Zito Bignami, R. [Istituto di Radiologia dell' Universita and Comitato Nazionale per l' Energia Nucleare, Rome (Italy)

    1962-02-15

    dostigaetsja putem sravnenija vozdejstvija na mlekopitajushhih rntege- novskih luchej s pikovoj moshhnost'ju v 150 kvr i obluchenija ih jelektronami iz betatrona moshhnost'ju v 15 mev. V nastojashhem doklade privodjatsja rezul'taty avtoradiograficheskogo issledo- vanija povedenija odnorodnyh kletok myshinogo timusa s ispol'zovaniem tritiro- vannogo timidina v kachestve predshestvennika deoksiribonukleinovoj kisloty. Rezul'taty stavjatsja v zavisimost' ot izmenenij v raspredelenii razmernyh kategorij kletochnyh populjacij i ot vesa organa. V rezul'tate obluchenija sootnoshenie mezhdu krupnymi i melkimi kletkami uvelichivaetsja; pogloshhenie tritirovannogo timidina umen'shaetsja v krupnyh i v malyh limfocitah. V ostroj faze vozdejstvija ne nabljudaetsja znachitel'nyh rashozhdenij mezhdu rezul'tatami obluchenija rentgenovskimi luchami i jelektro- nami v smysle razmerov kletok i markirovki krupnyh kletok. Otnositel'noe izmenenie projavljaetsja v mechenii malyh kletochek; v sootvetstvii s dannymi o vese organa zto obstojatel'stvo mozhet nahodit'sja v zavisimosti ot znachenij otnositel'noj bilogicheskoj jeffektivnosti bystryh nejtronov. V processe vosstnovlenija menee differencirovannye kletki projavljajut aktivnoe razmnozhenie, no procentnaja dolja zrelyh limfocitov ostaetsja ne- znachitel'noj. V rezul'tate obluchenija jelektronami moshhnost'ju v 15 mjev razmno- zhenie krupnyh kletok proishodit bolee intensivno v zavisimosti ot krivyh vremeni atrofii timusov. Na osnovanii vyshepri edennyh rezul'tatov vosstano- vitel'naja sposobnost', po-vidimomu, svjazana so stepen'ju porazhenija prostejshih kletok; dlja dannoj dozy zta sposobnost' sohranjaetsja duchshe pri obluchenii rentgenovskimi luchami, chem pri obluchenii jelektronami. (author)

  7. A Study of the Recoil Reactions of Three Isotopes of Ruthenium in Ruthenocene; Etude des Reactions d'Atomes de Recul de Trois Isotopes du Ruthenium dans le Ruthenocen; 0418 0417 0423 0427 0415 041d 0418 0415 0420 0415 0410 041a 0426 0418 0419 041e 0422 0414 0410 0427 0418 0422 0420 0415 0425 0418 0417 041e 0422 041e 041f 041e 0412 0420 0423 0422 0415 041d 0418 042f 0412 0420 0423 0422 0415 041d 041e 0421 0415 041d 0415 ; Estudio de las Reacciones de Retroceso de Tres Isotopos del Rutenio en el Rutenoceno

    Harbottle, G.; Zahn, U. [Brookhaven National Laboratory, Upton, NY (United States)

    1965-04-15

    de la viscosidad del medio, se investigaron tambien soluciones al 2% de rutenoceno en benceno que contenian 2, 10 y 20% de poliestireno. Los resultados fueron muy semejantes a los obtenidos en el caso del benceno puro. Tambien se estudiaron soluciones congeladas al 2 y 0,2% de rutenoceno en benceno: en este caso, los valores de retencion se aproximaron a los obtenidos para los cristales de rutenoceno a la misma temperatura. Si se define el 'efecto isotopico' como [1-(retencion de {sup 97}Ru/retencion de {sup 103}Ru)J x 100 (expresado en tanto por ciento), el valor de dicho efecto correspondiente a las soluciones de rutenoceno es de 42% ot por termino medio, mientras que los cristales y soluciones congeladas presentan valores mas bajos, que oscilan entre 10 y 15%. La mayor retencion y el menor efecto isotopico quiza puedan explicarse por un mayor amortiguamiento del impulso de retroceso en una red cristalina que en un liquido, aunque este sea viscoso. Pero tambien han de tenerse en cuenta otros factores como la relajacion del estado de carga de los distintos isotopos del rutenio consecutiva a la desexcitacion del estado nuclear compuesto. Se discutiran otras posibles explicaciones de estos resultados. (author) [Russian] Reakcii otdachi treh izotopov rutenija izuchalis' v molekuljarnom ''pirozhkovom'' soedinenii rutenosena [(C{sub 5}H{sub 5}){sub 2}RuJ . Izotopami, kotorye byli proizvedeny posredstvom reakcij (p, {gamma}) v reaktore, byli Ru{sup 97} (2,9 dnja), Ru{sup 103} (40 dnej) i Ru{sup 105}) (4,45 chasa), i ih otnositel'naja aktivnost' opredeljalas' posredstvom mnogokanal'nogo analiza scintilljacionnyh spektrov. Kristally rutenosena bombardirovalis' pri razlichnyh temperaturah i raspolozhenijah, i nabljudaemoe uderzhanie sostavljalo dlja uslovij komnatnoj temperatury Ru{sup 97}, 9.5{+-}0.1; Ru{sup 103}, 10.7 {+-} 0.2; i Ru{sup 105} , 9.9{+-}0.2%. sootvetstvenno. Otzhig kristallov pri temperature 140 Degree-Sign C vyzyval nebol'shoe uvelichenie uderzhanija, odnako

  8. Lattice Dynamics of Transition Metals; Dynamique de Reseau des Metaux de Transition

    Woods, A. D.B. [Chalk River Nuclear Laboratories, Chalk River, ON (Canada)

    1965-04-15

    {sup 12} c/s para {zeta} = 1.0. Si estas y otras particularidades observadas son anomalias de Kohn, sus posiciones son compatibles con las dimensiones de la superficie de Fermi propuesta por Lomer para los metales de la columna V. Se formula la hipotesis de que las sorprendentes diferencias existentes entre la relacion de dispersion del niobio y la del molibdeno (metales que, segun se cree, poseen estructuras de banda muy semejantes) reflejan diferencias en las energias de Fermi y, por tanto, en las superficies de Fermi de estos materiales. (author) [Russian] Dispersionnoe sootnoshenie chastota/volnovoj vektor v(q) dlja obychnyh vidov kolebanij nekotoryh ob{sup e}mno-centrirovannyh kubicheskih kristallov perehodnyh metallov bylo nedavno izmereno pri komnatnoj temperature. Krivye dispersii dlja niobija, izmerennye Nakagovoj i Vudsom, projavili nekotorye ochen' neobychnye cherty, i rezul'taty mozhno bylo privesti v sootvetstvie tol'ko s pomoshh'ju modeli Born fon Karmana, esli vkljuchit' vzaimodejstvija s ochen' otdalennymi chlenami rjada dal'she vos'mogo. Posledujushhie izmerenija Vudsom tantala dali ochen' pohozhie rezul'taty. Jeto ne udivitel'no, poskol'ku niobij i tantal nahodjatsja v V gruppe periodicheskoj tablicy i mnogie iz ih jelektronnyh svojstv odinakovy. Izmerenija krivyh dispersij molibdena Vudsom i Chenom i vol'frama Chenom i Brok- hauzom pokazali, chto, hotja u jetih metallov, kotorye nahodjatsja v gruppe VI periodicheskoj tablicy, dispersionnye sootnoshenija javljajutsja analogichnymi, jeti dispersionnye sootnoshenija sil'no otlichajutsja ot dispersionnyh sootnoshenij dlja niobija i tantala, nahodjashhihsja v gruppe V. Osnovnye cherty u(q) dlja molibdena i vol'frama ochen' blizko opisyvajutsja tret'im chlenom rjada simmetrichnoj po osjam silovoj modeli Born-fon Karmana, hotja nekotorye vazhnye cherty ne vosproizvodjatsja jetoj model'ju. Odnoj iz takih chert javljaetsja razitel'naja anomalija v prodol'noj [{zeta}{zeta}{zeta}] vetvi (L) dlja molibdena, gde

  9. Human Internal Contamination with Strontium-90 Titanate; Contamination Interne du Corps Humain par le Titanate de Strontium 90; 0412 041d 0414 ; Contaminacion Interna del Cuerpo Humano con Titanato de Estroncio-90

    Bradley, F. J.; Wald, N.; Wechsler, R. L. [Graduate School of Public Health and School of Medicine, University of Pittsburgh, Pittsburgh, PA (United States)

    1964-11-15

    'zovalis' tri metoda. Pervyj metod- izmerenie obluchenija vsego organizma. Ono provodilos' d-rom Ch.Millerom v Argonskoj nacional'noj laboratorii, chto pozvolilo opredelit' tol'ko verhnij predel iz-za nejarko vyrazhennogo spektra tormoznogo izluchenija stroncij-90 - ittrij-90 i ukazalo na pervonachal'noe soderzhanie radioaktivnosti vo vsem organizme ravnoe'4,8 mkkjuri. Vtoroj metod - sbor vsego kolichestva mochi i- kala dal 5 mkkjuri dlja pervyh 20 dnej.: Putem soedinenija jetogo kolichestva s predpolagaemym kolichestvom, ostavshimsja v organizme,bylo polucheno pervonachal'noe1 soderzhanie radioaktivnosti vo vsem-organizme 5,2. mkkjuri. Tretij metod -opredelenie .radioaktivnosti krovi ukazal na pervonachal'noe soderzhanie radioaktivnosti vo vsem organizme ravnoe -6 mkkjuri. Sootnoshenie vydelenija izotopa s mochoj i kalom v pervye 20.dnej sostavljalo 15,: 1 i 94% vydeljajushhegosja stroncija-90 prohodilo cherez zheludochno-kishechnyj trakt. Odnako interesno otmetit', chto znachitel'naja frakcjja byla nesomnenno rastvorima. K 20 dnju posle avarii bylo podschitano', chto zaderzhka izotopa v organizme sostavljala tol'ko 5% ot obshhego pogloshhenija. Daetsja opisanie metodov, ispol'zovavshihsja v jetot'period, dlja uvelichenija vyvedenija s'kalom s pomoshh'ju- MgSO i vydelenija s mochoj putem kombinacii gljukonata kal'cija's NH{sub 4}Cl. Predstavleny posledujushhie sposoby vyvedenija -odnovremennaja ocenka ostavshegosja v organizme kolichestva izotopa. (author)

  10. Sample Preparations Used in Biomedical Research and Training at the Special Training Division of the Oak Ridge Institute of Nuclear Studies; Methodes de Preparation d'Echantillons Employees dans la Recherche et la Formation Biologiques et Medicales a la Division de Formation Speciale de l'Institut d'Etudes Nucleaires d'Oak Ridge; Prigotovlenie obraztsov dlya biomeditsinskikh issledovanij i dlya uchebnykh tselej v otdele spetsial'noj podgotovki okridzhskogo instituta yadernykh issledovanii; Metodos de Preparacion de Muestras Aplicados en las Investigaciones Biomedicas y en la Capacitacion Profesional de la Division de Formacion Especial del Instituto de Estudios Nucleares de Oak Ridge

    Akers, L. K. [Oak Ridge Institute of Nuclear Studies, Oak Ridge, TN (United States)

    1965-10-15

    ambientales lleva a cabo una labor considerable de preparacion de muestras muy delgadas que permiten alcanzar una resolucion mas elevada de los espectros alfa. Para ello se utilizan procedimientos de deposito electrolitico a partir de mezclas disolventes. Se efectuan mediciones con una bateria especial de contadores Fairstein-Frisch de rejilla conectados a un analizador de 512 canales para el registro simultaneo de mas de un espectro. Tambien se utilizan detectores de estado solido y se comparan los resultados obtenidos con detectores de rejilla y de semiconductores. (author) [Russian] Pri osushhestvlenii issledovatel'skih i uchebnyh programm Otdela special'noj podgotovki ispol'zujut samye raznoobraznye metody prigotovlenija obrazcov. Oni vkljuchajut kak prostye derzhateli istochnikov, naprimer metallicheskie, kartonnye i plastmassovye, tak i ustrojstva dlja osazhdenija, v kotoryh ispol'zujutsja derzhateli iz nerzhavejushhej stali i steklovolokna, a takzhe special'nye derzhateli istochnikov dlja izmerenija obrazcov v zhidkostnyh schetchikah. Krome jetih metodov, razrabotan rjad metodov, predstavljajushhih osobyj interes pri izuchenii biomedicinskih problem. Odnim iz naibolee vazhnyh iz jetih metodov javljaetsja ispol'zovanie kataliticheskogo sinteza benzola, kotoryj razrabotan do takoj stepeni, chto obshhij vyhod sostavljaet bolee 90% . Jetot sintez mozhno ispol'zovat' dlja uglerodnyh soedinenij, predstavljajushhih interes pri provedenii jeksperimentov s indikatornymi kolichestvami i izuchenii problem opredelenija vozrasta. Poskol'ku sintez svjazan s polucheniem dvuokisi ugleroda na odnoj stadii i s gidrataciej metallicheskogo karbida na drugoj stadii, ego mozhno ispol'zovat' libo dlja izmerenija ugleroda-14 ili tritija, libo ih odnovremennogo izmerenija vo vremja jeksperimentov s dvojnym mecheniem. Znachitel'naja rabota prodelana v oblasti aktivacionnogo analiza biologicheskih materialov, v chastnosti, po osushhestvleniju radiojekologicheskih programm Otdela. Opisyvajutsja

  11. Biological Monitoring for Plutonium-241; Detection du Plutonium-241 par Controles Biologiques; Dozimetriya Plutoniya-241 v biologicheskikh materialakh; Determinacion del Plutonio-241 en Sustancias Biologicas

    Dalton, J. C.; McDonald, B. J.; Barnes, V. [United Kingdom Atomic Energy Authority, Windscale Works, Sellafield (United Kingdom)

    1965-10-15

    {pi}. El equipo construido hasta la fecha puede detectar 3 pCi de {sup 241}Pu en un recuento de 1 h. Esta cantidad representa la excretada por la orina durante 24 h a los 3 meses de absorber el 5% de la carga corporal maxima admisible (0,9 {mu}Ci). Seguidamente los discos se analizan para determinar los isotopos del plutonio emisores alfa colocandolos durante una semana sobre una placa nuclear, que se examina visualmente bajo el microscopio. (author) [Russian] Opisyvajutsja proishozhdenie i harakteristiki plutonija-241. Podcherkivajutsja soobrazhenija otnositel'no vreda jetogo jelementa dlja zdorov'ja i problemy ego opredelenija. Opisyvaetsja sistema scheta, vyrabatyvaemaja v nastojashhee vremja v Uindskejle dlja kolichestvennogo opredelenija plutonija-241 maloj aktivnosti v probah, sobiraemyh po programme biologicheskogo dozimetricheskogo kontrolja. Na nastojashhej stadii razrabotki jetot metod po men'shej mere stol' zhe chuvstvitelen, kak opisannye ranee, i obladae't preimushhestvami blagodarja prostote, bystrote i jekonomichnosti. Jetot metod prednaznachen v pervuju ochered' dlja analiza mochi dlja dopolnenija informacii, uzhe poluchennoj posredstvom radioavtograficheskogo analiza al'fa-aktivnyh radioizotopov plutonija. Dlja opredelenija kolichestva plutonija-241 ispol'zuetsja tot zhe samyj diskovyj istochnik, chto pozvoljaet sokratit' podgotovitel'nye raboty. Radioizotopy plutonija prezhde vsego izvlekajut iz proby mochi ili drugogo biologicheskogo materiala v sostojanii bol'shoj radiohimicheskoj chistoty posredstvom anionoobmena. V rezul'tate jelektroliza oni otkladyvajutsja na diske iz nerzhavejushhej stali. Neposredstvennyj otschet mjagkogo beta-spektra plutonija-241 (maksimal'naja jenergija 20 kjev, period poluraspada 13,3 goda) proizvoditsja s pomoshh'ju sistemy antisovpadenij, sostojashhej iz proporcional'nogo schetchika malogo ob{sup e}ma s gazovym potokom i iz zashhity s plasticheskim fosfornym scintilljatorom antisovpadenij. Razmery takovy, chto vse beta

  12. United Kingdom Food Irradiation Programme - Wholesomeness Aspects; Programme du Royaume-Uni Relatif a l'Irradiation des Aliments: Comestibilite; Programma oblucheniya pishchevykh produktov v soedinennom korolevstve - problemy sokhraneniya vkusovykh i pitatel'nykh kachestv; Programa del Reino Unido Relativo a la Irradiacion de Alimentos: El Problema de la Comestibitidad

    Hickman, J. R. [Wantage Research Laboratory (A.E.R.E.), Wantage, Berks. (United Kingdom)

    1966-11-15

    irradiacion es diferente. Las perdidas de vitaminas B producidas por irradiacion y cochura son acumulativas. No se ha observado efecto alguno en el valor nutritivo de las proteinas. En 1962, el Ministerio de Sanidad Publica del Reino Unido constituyo un Grupo de trabajo encargado de estudiar los efectos de las radiaciones en los alimentos y de presentar un informe sobre la necesidad de controles oficiales. En la memoria se examina el informe del Grupo de trabajo, publicado en 1964, en relacion con las pruebas de comestibilidad efectuadas en el Reino Unido. (author) [Russian] Daetsja opisanie ispytanij, provedennyh v Soedinennom Korolevstve, na sohranenie pishhevymi produktami vkusovyh i pitatel'nyh kachestv. Ispytanija velis' po programme obluchenija produktov pitanija. Kratkosrochnye issledovanija kormlenija krys, kur i svinej i dlitel'nye issledovanija kormlenija krys i myshej obluchennym kormom ne pokazali kakogo-libo vrednogo vlijanija jetogo korma na organizm. Opyty s kormleniem zhivotnyh byli prednaznacheny dlja vyjavlenija specificheskih processov obluchenija, i vse jeti processy ohvatyvajut ispol'zovanie nizkih ili umerennyh doz radiacii. Tak, zerno, obrabotannoe gamma-luchami dozoj v 20 000 i 200 000 rad, i zamorozhennye jajca (obluchennye dlja togo, chtoby ubit' salmonellae), obluchennye dozami 0,5 i 1,0 megarad, skarmlivali zhivotnym. Ispytyvalas' vetchina, obluchennaja dozoj 250 000 rad dlja prodl nija srokov ee hranenija, a takzhe vetchina, obluchennaja dozoj 2 megarada. V nastojashhee vremja provodjatsja dlitel'nye issledovanija po izucheniju voprosa sohranenija vkusovyh i pitatel'nyh kachestv ryby, obrabotannoj dozoj 0,6 megarada (maksimal'naja doza, kotoraja, verojatno, budet ispol'zovat'sja dlja obespechenija dlitel'nogo hranenija v zamorozhennom so- stojajii (0 Degree-Sign - 4 Degree-Sign C)). Kratkosrochnye opyty provedeny takzhe s kartofelem (10 00O rad) i koninoj (0,65 megarada). Pitatel'nye kachestva obluchennogo zerna, jaic, ryby i nekotoryh kormov dlja

  13. Quality Selection of Zircaloy-2 Canning Tubes by Ultrasonic Testing on Small Defects; Controle de la Qualite des Gaines en Zircaloy-2: Detection de Petits Defauts par les Ultrasons; Achestvennyjotb ortrub chatykh obolochek iz tsirkalloya-2 putem vyyavleniya nebol'shikh defektov s pomoshch'yu ul'trazvuka; Control de Calidad de los Revestimientos de Zircaloy-2 por Localizacion Ultrasonica de Pequenos Defectos

    Van Der Linde, A. [Reactor Centrum Nederland, Petten (Netherlands); Deraad, J. A. [Roentgen Technische Dienst N.V., Rotterdam (Netherlands)

    1965-09-15

    , skennirovalis' s pomoshh'ju edinichnogo zonda, rabotavshego v kachestve priemoperedatchika. Dlja dostizhenija neobhodimoj chuvstvitel'nosti ispytanija provodilis' v sostojanii pogruzhenija s chastotoj 4 Mgc,v to vremja kak trubki vrashhalis' so skorost'ju 120 ob/min. Daetsja opisanie mehanicheskogo pribora, obshhej ustanovki i voznikavshih trudnostej. V rezul'tate iz 93 proverennyh trubok u 21 byli obnaruzheny defekty v poperechnom napravlenii velichinoj ot 10 do 50 mikron po glubine. Takim obrazom, byla sostavlena otnositel'naja kvalifikacija trubok. (author)

  14. Plasma Confinement in Low-Density C Stellarator Discharges; Confinement du Plasma dans des Decharges a Faible Densite dans le Stellarator C; УДЕРЖАНИЕ ПЛАЗМЫ В ''СТЕЛЛАРАТОРЕ С'' ПРИ НИЗКОЙ ПЛОТНОСТИ РАЗРЯДА; Confinamiento de Plasma en Descargas de Baja Densidad en el Stellarator C

    Stodiek, W.; Grove, D. J.; Kessler, J. O. [Princeton University, Princeton, NJ (United States)

    1966-04-15

    skorosti poteri plazmy (otkachka) mogut imet' mesto iz-za omicheskih tokov nagreva. Odnako ranee provedennye jeksperimenty pokazali, chto otkachka sushhestvuet dazhe togda, kogda toki (normal'no neobhodimye dlja predotvrashhenija ohlazhdenija i rekombinacii) namnogo nizhe kriticheskih znachenij dlja vozbuzhdenija ionnyh voln. Odin jeksperiment, kotoryj, kazalos', podtverzhdaet gipotezu ionnyh volnovyh kolebanij, dopuskaet al'ternativnoe tolkovanie. Nastojashhij doklad posvjashhen jeksperimentam na ''stellaratore S'', v kotoryh provedeny izmerenija pri blizkih k nulju omicheskih tokah nagreva. Oni provodilis' pri nizkih nachal'nyh davlenijah (2-3 x 10{sup -6} tor) vodoroda i temperaturah jelektronov 1-2 jev. Uderzhivajushhee pole ravnjalos' obychno 12,3 kg; nebol'shoe kolichestvo izmerenij provodilos' pri 35 kg. Vrashhatel'noe preobrazovanie, ravnoe 0,75 {pi} bylo osushhestvleno s pomoshh'ju spiral'nyh obmotok s Script-Small-L =2 i Script-Small-L = 3. V jetih jeksperimentah s nizkoj plotnost'ju i nizkoj temperaturoj v''stellaratore S''sushhestvuet anomal'naja skorost' poter' pri chetyreh uslovijah raboty: 1) omicheskij nagrev, 2) nagrev za schet jelektronnogo ciklotronnogo rezonansa, 3) mikrovolnovyj omicheskij nagrev i 4) bez nagreva. My prihodim k vyvodu, chto ni nalichie aksial'nogo toka maloj velichiny, ni izmenenie plotnosti v predelah 5 x 10{sup 9} Less-Than-Or-Equal-To n{sub e} Less-Than-Or-Equal-To 2 x 10{sup 11} sm{sup -3} ne vlijajut, kak predstavljaetsja, na postojannuju vremeni poter' plazmy poperek uderzhivajushhego magnitnogo polja. Skorost' poter' nel'zja otnesti za schet otsutstvija ravnovesija, svjazannogo s konechnoj provodimost'ju. Vremja polnogo ischeznovenija plazmy vychisljaetsja po formule t 0,9 v/T{sub e} msek (V v kg, T{sub e} v jev; radius plazmy = 5 sm), pravil'nost' kotoroj nabljudalas' Hinnovom i Bishopom pri plotnostjah okolo 10{sup 13} sm{sup -3}. (author)

  15. Anisotropic Migration in Slab Lattices; Migration Anisotrope dans les Reseaux a Plaques; Anizotropicheskaya migratsiya v reshetkakh iz plastin; Migracion Anisotropica en Reticulados de Placas

    Honeck, H. C.; Quiquemelle, B. C. [Brookhaven National Laboratory, Upton, NY (United States)

    1965-08-15

    }{sub n} dara los coeficientes de difusion. En el Brookhaven National Laboratory se estan haciendo experimentos con placas alternadas de aluminio y polietileno. Los autores han seleccionado las siguientes secciones eficaces en un solo grupo: aluminio, {Sigma}a = 0, 01228 cm{sup -1}, {Sigma}s = 0, 08428 cm{sup -1}, {mu} = 0; polietileno, {Sigma}a - 0, 01947 cm-1, {Sigma}s = 2,593 cm{sup -1}, {mu} = 0,25. (author) [Russian] Odnoj iz samyh novyh oblastej primenenija jeksperimentov s impul'snymi nejtronami javljaetsja izmerenie kojefficienta diffuzii teplovyh nejtronov v razlichnyh napravlenijah v geterogennoj srede. Opisyvaetsja teoreticheskij metod, razrabotannyj s celyo predskazanija takih kojefficientov diffuzii, i predstavljajutsja nekotorye rezul'taty jeksperimentov, provodimyh v nastojashhee vremja v Brukhejvene. Interpretacija jetih jeksperimentov v znachitel'noj stepeni uproshhaetsja, esli jeksperimental'naja sborka javljaetsja bol'shoj. V jetom sluchae mozhno prenebregat' diffuzionnym ohlazhdeniem, spektry schitat' maksvellovskimi i rassmatrivat' edinstvennuju gruppu energii. Pri takom uproshhenii mozhno chislenno reshit' uravnenie perekosa dlja sluchaja plastinchatoj geometrii. My podstavljaem reshenie modeli Empty-Set (x, y, z, {Omega}, t) = exp (iB{sub 1}X + iB{sub 2}y - {lambda}t) Empty-Set (x, {Omega}) v uravnenie perenosa i reshaem Empty-Set (x, {Omega}) putem sochetanija metodov fil'trov dlja vyravnivanija dannyh i integral'noj teorii perenosa. Osnovnye preimushhestva jetogo metoda po sravneniju s sushhestvujushhimi sostojat v tom, chto legko vkljuchajutsja pogloshhenie i anijeotropiches- koe rassejanie i jachejka mozhet sostojat' iz mnogih podoblastej. Hotja sdelana popytka najti B{sub 1} i B{sub 2} s dannym sobstvennym znacheniem {lambda}, udobnee vmesto iB{sub l} postavit' kj i vmesto i V{sub 2} - k{sub 2} i opredelit' k{sub 2} s dannym k{sub 1} i {lambda} takom sluchae {lambda} mozhno vyrazit' v vide stelennogo rjada K{sup 2}{sub 1} i K{sup 2}{sub 2

  16. Some Applications of Short-Lived Radioisotopes in the Study of Metals; Applications Diverses des Radioelements de Courte Periode dans l'Etude des Metaux; РАЗЛИЧНЫЕ ПРИМЕНЕНИЯ КОРОТКОЖИВУЩИХ РАДИОЭЛЕМЕНТОВ ПРИ ИССЛЕДОВАНИЯХ МЕТАЛЛОВ; Aplicaciones de los Radioelementos de Periodo Corto en el Estudio de los Metales

    Kohn, A. [Institut de Recherches de la Siderurgie, Saint-Germain-en-Laye (France)

    1963-03-15

    znachitel'nyh konvektivnyh tokov v slitkah dlja pokovki. Opyty byli postavleny sledujushhim obrazom. V razlichnye periody vremeni posle plavki v slitki vesom 4 t, a takzhe v slitki vesom 30 - 60 t vvodilos' radioaktivnoe zoloto-198 v neznachitel'nyh kolichestvah. Mozhno bylo zametit', chto znachitel'naja chast' jetih bol'shih slitkov prodolzhala ostavat'sja ohvachennoj konvektivnymi tokami, dostatochno sil'nymi dlja togo, chtoby raspredelit' zoloto v bol'shom po ob{sup e}mu slitke spustja chas posle okonchanija plavki. (author)

  17. Chemical State of Radiobromine Formed by the Rb{sup 85}(n, {alpha}) Br{sup 82} Reaction; Etat Chimique Du Ra Diobrome Forme Par La Reaction {sup 85}Rb (n, {alpha}) {sup 82}Br; 0425 0418 041c 0418 0427 0415 0421 041a 041e 0415 0421 041e 0421 0422 041e 042f 041d 0418 0415 0420 0410 0414 0418 041e 0410 041a 0422 0418 0412 041d 041e 0413 041e 0411 0420 041e 041c 0410 , 041e 0411 0420 0410 0417 041e 0412 0410 041d 041d 041e 0413 041e 041f 0420 0418 0420 0415 0410 041a 0426 0418 0418 Rb{sup 85}(n, {alpha}) Br{sup 82}; Estado Quimico Del Radiobromo Formado Por La Reaccion {sup 85}Rb (n, {alpha}) {sup 82}Br

    Vlatkovic, M.; Kauiic, S. [' ' Ruder Boskovic' ' Institute, Zagreb, Yugoslavia (Croatia)

    1965-04-15

    los atomos de {sup 82}Br de energia muy elevada y a su incapacidad de regenerarse en los compuestos de rubidio investigados. (author) [Russian] Jetot doklad kasaetsja himicheskogo raspredelenija radioaktivnogo broma mezhdu ego naivysshim (BrO{sub 3}{sup -}) i bolee nizkimi (Br{sup -}, Br{sub 2}, BrO{sup -}) sostojanijami okislenija, poluchaemymi v rezul'tate jadernyh reakcij Rb{sup 85}(n, {alpha}) Br{sup 82} v rjade neorganicheskih tverdyh soedinenij rubidija. Obrazcy vysushennogo Rb{sub 2}SO{sub 4}, Rb{sub 2}S{sub 2}O{sub 8}, RbMnO{sub 4}, RbNO{sub 3}, Rb{sub 2}CO{sub 3} i RblO{sub 3} byli oblucheny nejtronami s jenergiej 14 Mjev na nejtronnom generatore (tipa T+d). Okazalos', chto v sluchae Rb{sub 2}SO{sub 4}, obluchennogo pri komnatnoj temperature ili pri -195 Degree-Sign C, priblizitel'no 8% ot obshhej aktivnosti broma-82 bylo obnaruzheno v bromatnoj frakcii, ostal'naja chast' soputstvovala bromidnoj frakcii. Obluchenie RbMnO{sub 4} and RbNO{sub 3} pri komnatnoj temperature davalo primerno 1% aktivnosti, sootvetstvujushhej bolee vysokomu sostojaniju okislenija broma, hotja v sluchajah Rb{sub 2}S{sub 2}O{sub 8} , Rb{sub 2}CO{sub 3} i RblO{sub 3} aktivnost' mozhno bylo obnaruzhit' tol'ko v bromidnoj frakcii. Nebol'shoe uvelichenie aktivnosti bromata nabljudalos' takzhe, kogda obluchennyj nejtronami Rb{sub 2}SO{sub 4} nagrevalsja do 250 Degree-Sign C. Pri bolee vysokih temperaturah (do 500 Degree-Sign C) aktivnost' perehodila vo frakciju, sootvetstvujushhuju bolee nizkomu sostojaniju okislenija. Nagrevanie obluchennyh RbMnO{sub 4} i RbNO{sub 3} ne vyzyvalo nikakogo okislenija broma. Hotja v sluchae s RbNO{sub 3} predvaritel'noe gamma-obluchenie dozoj v 22 Mrad ne imelo nikakogo vlijanija na raspredelenie jader otdachi broma, analiz Rb{sub 2}SO{sub 4} predvaritel'no obluchennogo gamma-luchami (55 Mrad), daval bolee vysokuju aktivnost' bromata po sravneniju s obrazcami, kotorye do nejtronnogo obluchenija byli tol'ko vysusheny pri 150 Degree-Sign C. 5 zakljuchenie

  18. Void Reactivity Effects in the Second Charge of the Halden Boiling Water Reactor; Effets Cavitaires dans la Deuxieme Charge du Reacteur a Eau Lourde Bouillante de Halden (HBWR); Ehffekty pustotnoj reaktivnosti vo vtoroj zag HBWR; Effectos de Cavitacion en la Segunda Carga del Reactor de Agua Pesada Hirviente de Halden (HBWR)

    Lunde, J. E. [OECD Halden Reactor Project (Norway)

    1964-02-15

    dinamicheskogo povedenija kipjashhego reaktora. Odnako teoreticheskoe opredelenie jetogo pokazatelja uslozhnjaetsja tem, chto neobhodimo znat' raspredelenie pustot v aktivnoj zone, podrobnye dannye o vlijanii raspredelenija pustot na moshhnost' trudno poddajutsja jeksperimental'nomu opredeleniju, i pojetomu jeksperimenty s imitirovannymi pustotami byli prigodny dlja proverki raschetov jeffektov pustoty. Dlja jetih jeksperimentov delajutsja predvaritel'nye teoreticheskie sravnenija. Primenjaetsja dvugruppovaja teorija diffuzii, i mozhno sdelat' vyvod o tom, chto dostignuta spravedlivaja soglasovannost' mezhdu teoriej i jeksperimentom dlja perturbacij v parametrah reshetki pri pustotnoj chasti ravnoj edinice pri nizkoj i vysokoj temperaturah. Odnako dlja promezhutochnyh pustotnyh chastej ustanovlena menee udovletvoritel'naja soglasovannost'. Dlja makroskopicheskogo rascheta jeffekta reaktivnost' primenjaetsja teorija vozmushhenij. (author)

  19. Inelastic Neutron Scattering from Doped Germanium and Silicon; Diffusion Inelastique des Neutrons dans du Germanium et du Silicium Contenant une 'Impurete'; Neuprugoe rasseyanie nejtronov na germanii i kremnii s prisadkoj; Dispersion Inelastica de Neutrones en Germanio y Silicio Deliberadamente Impurificados

    Dolling, G. [Chalk River Nuclear Laboratories, Chalk River, ON (Canada)

    1965-04-15

    razlichij chastot fononov ili jenergeticheskih shirin mezhdu chistymi obrazcami i obrazcami s prisadkoj. V naibolee blagoprijatnyh sluchajah takaja (otnositel'naja) tochnost' sostavljaet priblizitel'no 0,5% po chastote, s povysheniem do 2,0% dlja nekotoryh prodol'nyh opticheskih kolebanij v kremnii. (author)

  20. Szilard-Chalmers Processes in Ammonium Dihydrogen Phosphate as Studied by Electrophoresis and Electron Spin Resonance Techniques; Processus Szilard-Chalmers dans le Phosphate d'Ammonium Biacide Etudies par ELectro- Phorese et Resonance de Spin Electronique; 0418 0417 0423 0427 0414 ; Procesos Szilard-Chalmers en el Fosfato Monoamonico Estudiados por Electroforesis y Resonancia del Spin Electronico

    Fenger, J.; Nielsen, S. O. [Danish AEC Research Establishment, Riso (Denmark)

    1965-04-15

    pomoshh'ju jelektronno-spinovogo rezonansa (JeSR), my soobshhaem o rezul'tatah izuchenija s pomoshh'ju metodov jelektroforeza i jelektronno-spinovogo rezonansa otdel'nyh kristallov pervichnogo kislogo fosfata ammonija posle obluchenija nejtronami v teplovoj kolonke pri temperaturah mezhdu - 196 Degree-Sign i 40 Degree-Sign C. Spektry jelektronno-spinovogo rezonansa registrirovalis' pri ispol'zovanii otdel'nyh kristallov ND{sub 4}D{sub 2}PO{sub 4}, obluchennyh nejtronami. Byli najdeny chetyre sistemy linij. Tri iz nih, sostavljajushhie vneshnjuju chast' spektra, vosstanavlivajutsja v dublety v nekotoryh orientacijah kristalla, chto govorit o sverhtonkoj svjazi s fosforom-31. Central'naja chast' spektra mogla takzhe byt' poluchena pri chistom {gamma}-obluchenii. Odna iz sistem linij vo vneshnej chasti spektra byla proslezhena dlja gorjachih atomov otdachi v rezul'tate processa N{sup 14}(n, p)C{sup 14} i opredelena dlja radikalov fosfita, kotorye orientirovany v 8 razlichnyh napravlenijah v kristallicheskoj reshetke. Kratko obsuzhdajutsja rezul'taty teplovogo i radiacionnogo otzhiga, izuchennogo s primeneniem metodov jelektroforeza. Naibolee vazhnyj vyvod sostojal v tom, chto ND{sub 4}D{sub 2}PO{sub 4} i NH{sub 4}H{sub 2}PO{sub 4} posle nejtronnogo obluchenija pri temperature 4 Degree-Sign C, -78 Degree-Sign C i -196 Degree-Sign C otlichalis' po svoim uderzhanijam, kotorye priblizitel'no na 50% bol'she v ND{sub 4}D{sub 2}PO{sub 4} pri vseh treh temperaturah. Tri iz nih vosstanavlivajutsja v dublety v nekotoryh orientacijah kristalla, chto govorit o sverhtonkoj svjazi s fosforom-31. Do sih por ne najdeny dokazatel'stva v otnoshenii svjazi s fosforom-32. Mozhno takzhe poluchit' sil'nejshuju sistemu linij s pomoshh'ju chistogo gamma-obluchenija. Odna sistema linij proslezhena dlja gorjachih atomov otdachi i opredelena dlja fosfit-radikala. (author)

  1. Relative Biological Effectiveness of 14-MeV Fast Neutrons to Co{sup 60} Gamma-Rays in Einkorn Wheat; Efficacite Biologique Relative des Neutrons Rapides de 14 MeV par Rapport aux Rayons Gamma de {sup 60}Co sur l'Engrain; Otnositel'naya biologicheskaya ehffektivnost' bystrykh nejtronov s ehnergiej 14 MeV i gamma-luchej CO{sup 60} pri ikh dejstvii na pshenitsu odnozernyanku; EBR de los Neutrones Rapidos de 14 MeV y de los Rayos Gamma del {sup 60}Co en el Trigo Escanda Menor

    Fujii, T. [National Institute of Genetics, Misima (Japan)

    1964-05-15

    , sobrevivio entre 60 y 80% de las plantulas y en los grupos tratados con rayos gamma, la supervivencia fue del 100%. En cambio, en el grupo sometido a la irradiacion neutronica con la dosis mas elevada, solo sobrevivio un 4% de las plantulas. No se observaron mutaciones en el grupo testigo y el numero de plantas que presentaba retonos rayados crecio al aumentar la dosis de ambos tipos de radiacion. Se observaron retoflos con mutaciones en un 15% de las plantas sobrevivientes tratadas con la dosis inferior de neutrones y la misma frecuencia se registro para la dceis mayor de rayos gamma. Al parecer, la EBR de los neutrones de 14 MeV con respecto a los rayos gamma de {sup 60}Co, para la mutacion somatica, es 20 como minimo. (author) [Russian] Avtor izuchal OBJe nejtronov s jenergiej 14 Mjev i gamma-luchej Sobo pri ih dejstvii na pshenicu odnozernjanku s pomoshh'ju special'nogo lokusnogo metoda. Dlja opyta ispol'zovalis' semena generacii F{sub 1} gibrida mezhdu ishodnym sortom i mutantom Chlorina (mutant Chlorina byl poluchen kak edinstvennyj recessivnyj rentgenomutant; ot stadii sejanca do nastuplenija spelosti on byl odnorodno svetlozelenym s otnositel'no vysokoj vyzhivaemost'ju i urozhajnost'ju). U rastenij F{sub 1} byla normal'naja zelenaja okraska i normal'nyj harakter rosta. Pokojashhiesja semena Ft obluchali bystrymi nejtronami v dozah 0,5, 1,0 i 1,4 krad i gamma-luchami v dozah 4,3 8,6 i 12,9 krad. Mutacii ot dominantnyh normal'nyh zelenyh do Chlorina nabljudalis' posle oboih vidov obluchenija i pojavljalis' v list'jah i stebljah geterozigotnyh rastenij X{sub 1} v vide prodol'nyh polos. Okolo 80% semjan vzoshlo na kontrol'nyh uchastkah i na uchastkah posle obluchenija ca- mymi nizkimi dozami nejtronov i gamma-luchej, procent vshozhesti postepenno snizhalsja s povysheniem dozy pri oboih vidah obluchenija. Krome togo, takaja zhe tendencija nabljudalas' i na rannih stadijah rosta sejancev, kotoryj postepenno tormozilsja s povysheniem dozy. Soglasno jetim dannym nejtronnoe

  2. Carbon-14 and Hydrogen-3 Measurement by Means of a Liquid Scintillation Spectrometer: Colour Quenching; Mesure du Carbone-14 et du Tritium a l'Aide d'un Spectrometre a Scintillateurliquide: Extinction Chromatique; Izmerenie soderzhaniya Ugleroda-14 i Vodoroda-3 s pomoshch'yu zhidkostnogo stsintillyatsionnogo spektrometra. oslablenie tsveta; Influencia de la Extincion Cromatica en la Medicion del Carbono-14 y del Hidrogeno-3 por Espectrometria del Centelleo Liquido

    Iwakura, T.; Kasida, Y. [National Institute of Radiological Sciences, Chiba (Japan)

    1965-10-15

    TRI-CARB, model' 314 EH2. Nastrojka diskriminatora sostavljala 100-1000 delenij dlja krasnogo kanala i 186-1000 delenij dlja zelenogo. Vysokoe naprjazhenie, primenjaemoe dlja fotoumnozhitelja, vybrali dlja togo, chtoby obespechit' uravnoveshennuju tochechnuju rabotu v krasnom kanale pri neoslablennom obrazce. Koncentracija krasok byla izuchena po stepeni oslablenija. Vsledstvie harakternosti dliny voln sveta, ishodjashhego iz scintilljatornyh sistem i reakcii fotoumnozhitelej (reakcija S-I), predpolagalos', chto krasno-zheltyj rastvor, kotoryj imeet maksimum pogloshhenija pri 400 - 500 mmk budet imet' samyj bol'shoj jeffekt oslablenija. Chtoby ocenit' obshhee oslablenie cveta dlja opredelenija kojefficienta obshhego pogloshhenija ispol'zovalos' sledujushhee otnoshenie: A = ({Sigma}A{sub i}W{sub i})/({Sigma}W{sub i}), gde W{sub i} - otnositel'naja chuvstvitel'nost' fotoumnozhitelja k svetu s dlinoj volny i mmk; a A{sub i} - pogloshhenie sveta s dlinoj volny i mmk v predelah ispol'zuemogo spektra. Obshhee pogloshhenie bylo rasschitano dlja kazhdogo intervala v 40 mmk, naprimer dlja 360 - 400, 400 - 440 i t.d. do 520 - 560 mmk. Jekvivalentnoe pogloshhenie 1/A v zavisimosti ot jeffektivnosti scheta pokazyvaet linejnuju zavisimost' v shirokom diapazone jeffektivnosti scheta. Krivye zavisimosti kojefficienta diskriminatora ot jeffektivnosti scheta pokazyvajut, chto, kogda oslablenie cveta stanovitsja sil'nym, krivaja oslablenija cveta otdeljaetsja ot krivoj himicheskogo oslablenija pri schete ugleroda-14. S drugoj storony, proizvedennye pri schete vodoroda-3 analogichnye izmerenija ne pokazyvajut razdelenija dvuh krivyh oslablenija. (author)

  3. New Methods and Facilities for the Measurement of Physical Properties of Reactor Components and Irradiated Materials; Nouveaux Procedes et Instruments de Mesure des Proprietes Physiques des Elements de Reacteur et des Matieres Irradiees; Novye metody i sredstva izmereniya fizicheskikh s vojstv komponentov reaktora i obluchennykh materialov; Nuevos Metodos y Equipos para Medir Propiedades Fisicas de Componentes de Reactor y de Materiales Irradiados

    Foerster, F.; Mueller, P. [Institut Dr. Foerster, Reutlingen, Federal Republic of Germany (Germany)

    1965-09-15

    kolebanija ili putem izmerenija polushiriny rezonansnoj krivoj. Privodjatsja primery izmerenij vosstanovlenija posle radiacionnogo.povrezhdenija i posle plasticheskoj deformacii, a takzhe primery stepeni gra- fitizacii. Opisyvajutsja obnaruzhenie defektov i kolebanija plotnosti grafitovyh blokov. Krome togo ob{sup j}asnjaetsja metod issledovanija zakreplenija tabletok iz UO{sub 2} v tonkostennyh austenitnyh trubkah. Opisyvaetsja special'naja pech' dlja izuchenija uprugogo i neuprugogo povedenija ''gorjachih'' obrazcov pri temperaturah ot 20 do 1000 Degree-Sign C. Obsuzhdaetsja kontrol' kachestva cvetnyh metallov putem izmerenija jelektroprovodnosti s pomoshh'ju vihrevyh tokov. Opisyvaetsja pribor dlja beskontaktnogo izmerenija jelektroprovodnosti cvetnyh metallov. Ob'jasnjaetsja sootnoshenie mezhdu jelektroprovodnost'ju i deformaciej pod naprjazheniem cvetnyh metallov i splavov. Osoboe vnimanie obrashhaetsja na izmerenie nebol'shih po razmeru obrazcov. Opisyvaetsja ustrojstvo dlja distancionnyh prjamyh izmerenij v ''gorjachej'' zone reaktora. Rassmatrivaetsja zavisimost' jelektroprovodnosti ot doz obluchenija. Opisyvaetsja pribor dlja izmerenija pronicaemosti, ostatochnoj magnitnoj indukcii i kojercitivnoj sily kak funkcii mehanicheskogo naprjazhenija, uprugoj i plasticheskoj deformacii i doz obluchenija. Opisyvajutsja izmerenija izmenenij magnitnyh svojstv kak funkcii uprugogo naprjazhenija i plasticheskoj deformacii. Rassmatrivaetsja vlijanie obluchenija na pronicaemost' i kojercitivnuju silu. Opisyvaetsja pribor dlja bystrogo izmerenija i neposredstvennogo opredelenija pronicaemosti komponentov iz nerzhavejushhej stali. Ob'jasnjaetsja sootnoshenie mezhdu pronicaemost'ju i soderzhaniem D ferrita. Rassmatrivajutsja rezul'taty izmerenij procentnogo soderzhanija D ferrita v svarnyh shvah trubok iz nerzhavejushhej stali i izmerenij osazhdenija D ferrita kak funkcii plasticheskoj deformacii (svobodnaja kovka toplivnyh jelementov reaktora). (author)

  4. Movement of Radioactive Effluents in Natural Waters at Hanford; Le Mouvement des Effluents Radioactifs dans les Eaux Naturelles a Hanford; 0414 0412 0418 0416 0414 ; Movimiento de los Efluentes Radiactivos en Aguas Naturales en Hanford

    Honstead, J. F.; Foster, R. F.; Bierschenk, W. H. [Hanford Laboratories Operation, Hanford Atomic Products Operation, General Electric Company, Richland, WA (United States)

    1960-07-01

    porod, prezhde chem dostignut podzemnyh vod. Bol'shinstvo radioaktivnyh materialov zaderzhivaetsja putem pogloshhenija ili drugih reakcij pri prohozhdenii cherez pochvu. Ochishhennaja takim obrazom voda i neznachitel'nye othody, dostigajushhie podzemnyh vod, napravljajutsja vmeste s nimi k reke Kolumbii. Skorost' i napravlenie opredeljajutsja formoj vodnogo gorizonta i gidravlicheskimi harakteristikami vodonosnyh plastov. Bol'shie ob{sup e}my vody, slivaemye v grunt, okazali korjonnoe izmenenie na harakter gorizonta podzemnyh vod. Ishodja iz izmerennoj pronicaemosti vodonosnyh plastov, srednee vremja prohozhdenija vody ocenivaetsja v 180 let. Priznaetsja takzhe to, chto maksimal'naja skorost' mozhet znachitel'no prevyshat' srednjuju velichinu. Odnako, vlijanie pogloshhenija ili drugih reakcij ochen' sil'no zamedljajut dvizhenie rastvorennogo materiala po otnosheniju k skorosti dvizhenija vody. Ne bylo obnaruzheno proniknovenija produktov delenija iz rajonov udalenija v rechnuju vodu. (author)

  5. Investigations on Pasteurization of Cold Marinades by {sup 60}Co Gamma Rays; Recherches sur la Pasteurisation a Froid De Marinades par les Rayons Gamma du {sup 60}Co; Issledovaniya pasterizatsii kholodnykh marinadov gamma-luchami; Investigaciones Sobre la Pasteurizacion de Escabeches Frios por Irradiacion Gamma con {sup 60}Co

    Schoenborn, W.; Kinkel, R J.; Hafferl, W. [Battelle Institut e.V., Frankfurt/Main, Federal Republic of Germany (Germany)

    1966-11-15

    Degree-Sign S bylo takzhe dostignuto posle perioda, v tri raza bol'shego chem obychno, posle obluchenija 160 kradami. Smertel'naja doza 99 dlja treh izolirovannyh shtammov molochnokislotnyh bakterij, obluchennyh v solepeptonovom rastvore, sostavila sootvetstvenno 113, 165 i 144 krad. Poskol'ku pri 15 Degree-Sign S rost mikrobov zaderzhivaetsja, v to vremja kak pri 20 Degree-Sign S on prakticheski ogranichen, period stojkosti pri temperature v 18 Degree-Sign S mozhno uvelichit' v dva raza lish' putem obluchenija 280 krad. Organolepticheskie ispytanija osnovany na preferencial'nom analize s pomoshh'ju devjatishagovoj gedonicheskoj shkaly i na differencial'nyh ispytanijah (ispytanija treugol'nika); oni osushhestvljajutsja soveshhaniem jekspertov. Pri 70 kradah vkus ostaetsja priemlemym; pri 140 kradah imeetsja otchetlivyj vkus luchej; pri 280 kradah vkus nepriemlem. Sushhestvennoe uluchshenie vkusa dostigaetsja pri obluchenii pri nizkih temperaturah (-30 Degree-Sign S) i pri dobavlenii askorbinovoj kisloty, sorbita i specij. Jeksperimenty prodolzhajutsja. (author)

  6. Nuclear Materials Management in a Recovery Facility for Unirradiated Enriched Uranium; Gestion des Matieres Nucleaires dans une Installation de Recuperation d'Uranium Enrichi Non Irradie; Administrativno-khozyajstvennyj uchet yadernykh materialov na ustanovke po regeneratsii neobluchennogo obogashchennogo urana; Administracion de Materiales Nucleares en una Planta de Recuperacion para Uranio Enriquecido No Irradiado

    Jasny, G. R. [Union Carbide Corporation, Oak Ridge, TN (United States)

    1966-02-15

    izvlekajutsja razlichnye vidy neobluchennogo obogashhennogo urana. V nastojashhee vremja usta- novka Y-12 po regeneracii osnashhena polunepreryvnoj potochnoj liniej, vkljuchaja rastvorenie, szhiganie, vyparivanie, izvlechenie, denitraciju i gidroflorinaciju produkta. Oborudovanie po pererabotke i hraneniju imeet ogranichennye razmery i obladaet obshhej propusknoj sposob- nost'ju v neskol'ko sot kilogrammov obogashhennogo urana v mesjac. Snabzhenie dlja processov izvlechenija postupaet kak s samoj ustanovki, tak i iz drugih predprijatij Komissii po atom- noj jenergii v Soedinennyh Shtatah. V tot ili inoj moment jeto snabzhenie vkljuchaet lom ne- obluchennogo obogashhennogo urana prakticheski vseh vozmozhnyh vidov. Fizicheskij kontrol' uspeshno osushhestvljaetsja blagodarja sledujushhim faktoram: 1. Tshhatel'nost' konstruirovanija oborudovanija, chto obespechivaet vozmozhnost' chistki i vyborki prob i svodit k minimumu zahvat materialov. 2. Nepreryvnyj dozimetricheskij kontrol' vseh othodov i putej prohozhdenija othodov i jeffluentov kak cherez sistemu kanalizacii, tak i cherez vytjazhnye truby, a takzhe nad radioak- tivno zagrjaznennym musorom. 3. Periodicheskie fizicheskie proverki nalichnyh materialov. 4. Tshhatel'naja vyborka prob i analiz ih kak po vneshnim putjam snabzhenija matermalami, tak i po putjam prohozhdenija produkta. 5. Strogij kontrol' nad kachestvom analiza i vyborki prob. 6. Vozlozhenie otvetstvennosti za uchet materialov na operativnyj, a ne na uchetnyj personal. 7. Tshhatel'nyj instruktazh operativnogo personala. Informacija, postupajushhaja v sistemu ucheta jadernyh materialov, sobiraetsja pri pomoshhi sistemy kartochek, blizko soprovozhdajushhih fizicheskij put' prohozhdenija materialov; inache govorja, tozhdestvo kazhdoj partii sohranjaetsja pri pomoshhi sootvetstvujushhej kartochki, i otdel pouch e tu jadernogo materiala uvedomljaetsja ob udalenii partii posredstvom peredachi emu sootvetstvujushhej kartochki jetoj partii. Bol'shaja chast' uchetnyh

  7. Plant Measurement, Sampling and Analysis for Accountancy Purposes with Particular Reference to Separation Plants at Windscale; Mesures, Echantillonnages et Analyses en Usine a des Fins Comptables, Notamment dans les Installations de Separation de Windscale; Izmereniya, vzyatie obraztsov i analizy v tselyakh ucheta na opyte ustanovki razdeleniya radioizotopov v uindskejle; Medicion, Muestreo y Analisis para Fines Contables, Especialmente en las Plantas de Separacion de Windscale

    Davidson, A. S.; Elliott, F.; Powell, R.; Swinburn, K. A. [United Kingdom Atomic Energy Authority, Windscale and Calder Works, Cumberland (United Kingdom)

    1966-02-15

    . Vzjatie obrazcov rastvorov v processe dozirovki proizvoditsja s pomoshh'ju trub po otkachke posle polnoj gomogenizacii rastvora. Dlja ''padajushhih'' potokov tam, gde trebuetsja bol'shaja tochnost', byl skonstruirovan probootbornik, berushhij proby nepreryvno, kotoryj ispol'zuetsja na novoj ustanovke pri zagruzke. Sverlenie metallicheskih bolvanok v Und- skejle schitaetsja normal'nym sposobom vzjatija obrazcov, togda kak dlja drugih tverdyh sostojanij metod zakljuchaetsja v gomogenizacii do teh por, poka jeto vozmozhno (naprimer, konusnyj smesitel' V ispol'zuetsja dlja okisi plutonija) i zatem beretsja proba. Chto kasaetsja himicheskih analizov, to trebuemaja ot metoda tochnost' zavisit ot celogo rjada opredelenij v kazhdom otdel'nom periode vychislenija. Tak, bol'shoe kolichestvo analizov trebuetsja dlja chetkogo, no netochnogo metoda. Bolee jekonomichnym mozhet okazat'sja ispol'zovanie gorazdo men'shego kolichestva opredelenij s pomoshh'ju bolee tochnogo metoda. Podrobno obsuzhdajutsja metody opredelenija plutonija, naprimer: a) radiohimija, b) kolorimetricheski ispol'zuemyj toronol, v) otdelenie plutonija v sovokupnosti s EDTA i obratnym titrovaniem izlishnego EDTA, g) titrometrija, d) izotopnoe rastvorenie soprovozhdaemoe mass-spektrometriej i e) differencial'naja spektrometrija. Podrobno obsuzhdajutsja metody opredelenija urana, naprimer: a) gravimetrija kak U308, b) jefirnaja jekstrakcija, soprovozhdaemaja gavimetriej ili kolorimetriej, v) titrometrija, g) izotopnoe rastvorenie, soprovozhdaemoe mass-spektrometriej i d) opredelenie obogashhenija s pomoshh'ju mass-spektrometrii ili spektrografii linejnogo smeshhenija izluchenija. Vmeste so vsemi metodami vychislenij ispol'zujutsja standarty dlja togo, chtoby vesti kachestvennyj kontrol' i pokazat' ljubuju netochnost', kotoraja trebuet ispravlenija. Dajutsja tochnye vykladki vseh metodov i ukazyvajutsja metody, fakticheski ispol'zovavshiesja dlja novoj ustanovki po razdeleniju. (author)

  8. Analysis of Scan Records with a Recording Densitometer - The ''Re-Scanner''; Etude d'un Grand Collimateur a Focalisation et Fort Pouvoir de Resolution: Resultats; Analiz skenogramm s pomoshch'yu registriruyushchego densitometra - ''re-skenner''; Diseno y Funcionamiento de un Gran Colimador Enfocado de Alto Poder de Resolucion

    Harris, C. C.; Bell, P. R.; Satterfield, M. M.; Ross, D. A.; Jordan, J. C. [Oak Ridge National Laboratory, TN (United States)

    1964-10-15

    kontrastnosti. Porogovyj kontrol' d a et ljuboj ''sokrashhennyj uroven'' vybora. Rabota provoditsja bystro, i diagramma mozhet byt' reskennirovana v techenie nebol'shogo promezhutka vremeni, neobhodim ogo dlja poluchenija pervonachal'nogo izobrazhenija. Issledovanija v oblasti klinicheskogo skennirovanija pochti ljubogo organa ili rajona., predstavljajushhego interes, pokazyvajut, chto rerazvertyvatel' daet informaciju, ne vidimuju snachala na di agram mah pri pervonachal'nom skennirovanii. Jeto bylo osobenno poleznym pri opredelenii st atisticheskogo znachenija nebol'shih izmenenij v kojefficiente scheta pri skennirujushhem izobrazhenii. . Pri diagrammah, poluchennyh metodom skennirovanija, bol'shogo dinamicheskogo diapazo n a , gle nikakoj otdel'nyj sokrashhennyj urov en' udovletv orit el'no ne pokazy vaet vse rajony, predstavljajushhie interes, vnov' byli neobhodimy rerazvertyvateli na nekotoryh sokrashhennyh urovnjah. V popytke preodolet' je t u trudnost' ispol'zovalsja dvuhdiapazonnyj chuvstvitel'nyj jel em en t , kotoryj ohvatyvaet rajon registracii vokrug o bl a sti nabljudenija glavnogo chuvstvitel'nogo jel em en t a . Po krajnej m er e , vozmozhny tri vida jek s pluatacii pribora s dvuhdiapazonnym chuvstvitel'nym jelemen tom: 1) ''normal'naja'' je k s pluatacija; 2) ignorirovanie obshhej plotnosti izobrazhenija i reakcija tol'ko na nebol'shie izmenenija, ustanavlivaja takim obrazom svoj sobstvennyj sokrashhennyj uroven'; 3) soobshhenie tol'ko o vnezapnyh izmenenijah v plotnosti registracii. Po-vidimomu, vozmozhny takzhe drugie vidy. Jeto sravnitel'no prostoj i nedorogostojashhij pribor obespechivaet okazanie cennoj pomoshhi v interpretacii diagramm, proizvedennyh metodom skennirovanija. (author)

  9. Non-Destructive Methods for Determining Burn-Up in Nuclear Fuel; Methodes Non Destructives d'Evaluation du Taux de Combustion dans le Combustible Nucleaire; Metody opredeleniya vygoraniya v yadernom toplive bez razrusheniya obraztsa; Metodos No Destructivos para Determinai el Grado de Combustion de los Elementos Combustibles Nucleares

    McGonnagle, W. J. [Illinois Institute of Technology, Chicago, IL (United States)

    1966-02-15

    priborov, ih chuvstvitel'nost' i ih predely. Predlagajutsja metody analiza bez razrushenija obrazca s ispol'zovaniem stabil'nyh izotopov, obrazujushhihsja vo vremja processa delenija. Pri ispol'zovanii stabil'nyh izotopov detal'naja istorija radiacii priobretaet vtorostepennoe znachenie, a vremja ohlazhdenija voobshhe ne imeet znachenija. K tomu zhe imejutsja bolee tochnye dannye dlja stabil'nyh produktov raspada. Iz stabil'nyh izotopov, poluchennyh v processe delenija, naibolee poleznymi javljajutsja cirkonij, molibden, rutenij i neodim. Obsuzhdajutsja predlagaemye metody analiza bez razrushenija obolochki s ispol'zovaniem stabil'nyh izotopov. (author)

  10. The Design and Performance of a Large High resolution Focusing Collimator; Etude d'un Grand Collimateur a Focalisation et Fort Pouvoir de Resolution: Resultats; Konstruktsiya i kharakteristika krupnogo fokusiruyushchego kollimatora s vysokoj stepen'yu razresheniya; Diseno y Funcionamiento de un Gran Colimador Enfocado de Alto Poder de Resolucion

    Harris, C. C.; Bell, P. R.; Satterfield, M. M.; Ross, D. A.; Jordan, J. C. [Oak Ridge National Laboratory, TN (United States)

    1964-10-15

    udlinennogo svincovogo kollimatora nanosit ushherb osnovnym konstrukcionnym celjam iz - z a uvelichenija skorosti sch et a , esli ne ispol'zuetsja takzhe krupnyj det ek tor. Avtory sproektirovali i sozdali svincovyj kollimator s 91 otverstiem dlja ispol'zovanija s d et ektorom NaJ (T 1 ) r a zm er om 13,5 h 7,5 s m . Fokus nahoditsja na rasstojanii 24 sm ot d et ek tora , a prostranstvennyj ugol vosprijatija analogichen uglam fokusirujushhih kollimatorov pri odnovremennom ispol'zovanii ih s detektorami na 7,5 sm . Maksimal'naja dlina sostavlja et 16,5 sm ; obychnaja dlina konstrukcii sost avlja et 14 sm . Pri dannyh velichinah dliny opticheskie ''okruzhnosti razreshenija'' sostavljajut sootvetstvenno 1,2 i 0,77 sm . Jeti konstrukcii dajut sledujushhee: 1 . Bol e e dlinnoe fokusnoe r a s stojan i e s odn o vremennym uvelicheniem jeffektivnosti scheta blagodarja b ol e e krupnomu ljuminoforu. 2 . Svincovyj kollimator s razreshajushhej sposobnost'ju, kotoruju mozhno sravnit' s bolee korotkimi kollimatorami iz zolot a (skennogramma t ochechnogo istochnika C s-V a 137 imeet di ametr v sego 7 m m ) . 3. Kollimator s vysokoj stepen'ju razreshenija dlja skennirovanija chelovecheskogo organizma i melkih zhivotnyh. 4. Osnovnaja konstrukcija sborki dlja ispol'zovanija kollimatorov s bolee krupnym prostranstvennym uglom dlja uvelichenija jeffektivnosti scheta. Polucheny skennogrammy v sego organizma s primeneniem zolota -198 i jod a -131. Obnaruzhena vozrosshaja jeffektivnost' i razreshenie 14-sm kollimatora. Na skennogramme sobaki s 16,5 sm kollimatorom horosho vidna koncentracija aktivnosti, imejushhaja, ochevidno, v Diametre menee 6m m; aktivnost',lish' v 5 raz prevyshajushhaja ''fon organizma'', vse zhe byla chetko otdelena rasstojaniem 6 mm ot istochnika diametrom 1,8 sm s bolee vysokim (v 50 raz) urovnem aktivnosti. (author)

  11. Critical Survey of the Analysis of Microscopic Distribution of some Bone-Seeking Radionuclides and Assessment of Absorbed Dose; Analyse de la Distribution Microscopique de Radionucleides Osteophiles et Determination de la Dose Absorbee; Kriticheskij obzor dannykh analiza mikroskopicheskogo raspredeleniya otkladyvayushchikhsya v kostyakh radioizotopov i opredelenie pogloshchennoj dozy; Estudio Critico de la Distribucion Microscopica de Algunos Radionuclidos Osteofilos y Evaluacion de la Dosis Absorbida

    Jee, W. S.S.

    1964-10-15

    raspredelenija'dozy, vkljuchajushhee opisanie neodnorodnogo raspredelenija radiacii, protivorechashhego prinjatoj teorii odnorodnogo raspredelenija, poluchennogo na osnovanii dannyh zaderzhki izotopov vo vsem organizme. Bez nekotorogo znanija mikroskopicheskogo raspredelenija dozy vo vremeni i prostranstve slishkom legko sdelat' nevernye vyvody i propustit' vazhnye zakljuchenija pri popytke poluchit' sravnitel'nye dannye o toksichnosti radioizotopov. Ob{sup e}m opublikovannoj literatury po izmereniju mikroskopicheskogo raspredelenija doz radiacii ochen' ogranichen, chto svjazano so slozhnost'ju problemy. Sushhestvujushhie metody vkljuchajut avto-radiografiju i ochen' trudoemki. Oni vkljuchajut takzhe podschet raspadov i mikrodensimetriju. Polnoe raspredelenie dozy dlja dannoj kosti vo vremeni i prostranstve javljaetsja ogromnoj zadachej. Mikroskopicheskoe raspredelenie v skelete otkladyvajushhihsja v kostjah izotopov (radij-226, stroncij-90, plutonij-239 i radioaktivnyj torij-228) sluzhit prekrasnoj illjustraciej slozhnosti problemy. Pervonachal'naja doza obluchenija i doza, izmenjajushhajasja so vremenem, opisany dlja radija i plutonija, v osobennosti podcherkivaetsja neodnorodnost' raspredelenija dozy v kostjah i razlichnyh uchastkah vnutri kosti. Naprimer, maksimal'nye poverhnostnye trabekuljarnye otlozhenija plutonija v pozvonkah v 1,5 raza vyshe, chem maksimal'nye koncentracii v trabekulah metafiza bedra. Kojefficient otnoshenija doz poverhnostnyh otlozhenij plutonija v razlichnyh uchastka distal'nogo otdela bedra raven: trabekuly metafiza - 3; jendostil'- 2,6; trabekuly jepifiza - 1,5; gaversovy kanaly - 1,2 i peristil' - t. Maksimal'nye lokalizovannye poverhnostnye otlozhenija v trabekulah pozvonkov v 35 - 66 raz vyshe rasschitannoj srednej moshhnosti dozy v rezul'tate zaderzhki izotopov v organizme. Obsuzhdajutsja izmenenija s techeniem vremeni nachal'noj neodnorodnoj lokalizacii radija i plutonija v otnoshenii haraktera kletochnogo vosproizvodstva kosti i poteri

  12. Physical and Chemical Analysis of the Germinating and Nutritional Properties of Irradiated Wheat; Analyse Physico-Chimique des Caracteristiques Germinatives et Nutritives du Ble Irradie; Fizicheskie i khimicheskie analizy svojstv rosta i pitatel'nykh kachestv obluchennoj pshenitsy; Analisis Fisicoquimico de Trigo Irradiado: Estudio de sus Caracteristicas Germinativas y Nutricionales

    Pahissa Campa, J.; Gabarain, R. V.A.; De Pahissa, M. H.H. [Comision Nacional de Energia Atomica (Argentina); Bassa, L. [Junta Nacional de Granos, Buenos Aires (Argentina)

    1966-11-15

    transcurridos diversos lapsos. Se apreciaron distintas variaciones en los valores analiticos determinados, variaciones que dependian de la dosis. En cuanto a la textura, olor, color y sabor del pan, se observaron diferencias sumamente marcadas respecto al testigo, para las dosis mas elevadas. Para evaluar el valor alimenticio del grano irradiado, se emplearon ratas a las cuales se les incluyo en la dieta dicho material. La incorporacion se realizo inmediatamente despues de la irradiacion, y con posterioridad a lapsos variables. Se controlo la evolucion de los animales y fundamentalmente el cuadro hematico y medula osea. (author) [Russian] Pshenicu obluchali razlichnymi dozami s cel'ju opredelit' himicheskoe i fizicheskoe vlijanie obluchenija na celoe zerno (ego povedenie kak semeni) i muku (pishhevaja cennost'). V opyte ispol'zovali raznovidnost' pshenicy Surena M. A. G., kul'tiviruemoj v Argentine, ona byla postavlena Nacional'noj organizaciej po pshenice. Byl primenen pribor kanadskaja gamma-kamera 220 s istochnikom kobal't-60 moshhnost'ju 13 000 kjuri, sposobnym davat' dozu priblizitel'no 1 mrad/chas. Pshenicu obluchali dozami 10, 15, 20, 50,100,150, 200,-300, 500,1000, 1500 i 2000 kilorad. Byli opredeleny sledujushhie analiticheskie velichiny: a) po celomu zernu - ves 1 gektolitra, vlazhnost', procent proteina (soderzhanie azota h 13,5), cifra Zeleny, soderzhanie zoly, sposobnost' k prorastaniju (2 i 3 dnja); b) po muke - vlazhnost', procent proteina (soderzhanie azota h 13,5), cifra Zeleny, soderzhanie zoly, alkogol'naja kislotnost', soderzhanie solodovogo sahara, soderzhanie zhidkoj klejkoviny, soderzhanie suhoj klejkoviny, farintrafi- cheskie velichiny (pogloshhenie vody, vremja razvitija, stepen' poristosti, shhup dlja izmerenija vlazhnosti Brabendera), al'veograficheskie velichiny (soprotivlenie testa raskatyvaniju, rastjagivanie, stepen' i skorost' deformacii, sootnoshenie soprotivlenija na raskatyvanie'i raskatyvanija), velichiny rasshirenija (rabota, trebuemaja dlja

  13. Study of Fluidized-Bed Control Rods; Etude de Barres de Controle Fluidisees; Izuchenie reguliruyushchej sistemy, ispol'zuyushchej suspenziyu pogloshchayushchikh chastits; Estudio Sobre Barras de Control de Lecho Fluidificado

    Blair, D. J. [General Nuclear Engineering Corporation, Dunedin, FL (United States); Driscoll, M. J.; Dalton, G. R.; Parkinson, T. F. [Department of Nuclear Engineering, University of Florida, Gainesville, FL (United States)

    1964-06-15

    sistemu trub podobno sistemam upravlenija, razrabatyvaemym dlja reaktorov s suspenziej topliva. Nekotorye iz vozmozhnyh preimushhestv koncepcii SPCh: 1) ustranjaetsja bol'shinstvo vvodov v verhnjuju chast' korpusa i uproshhaetsja process peregruzki topliva; 2) pri vozniknovenij avarii v rezul'tate poteri potoka proishodit avtomaticheskaja bystraja ostanovka reaktora; 3) osevoe raspredelenie moshhnosti mozhet izmenjat'sja v rezul'tate primenenija special'nyh kanalov ili chastic peremennoj velichiny; 4) rezkoe vozrastanie potoka v vodjanom zazore mozhet byt' umen'sheno dlja chastichno izvlechennogo upravljajushhego sterzhnja; 5) mozhno umen'shit' temperaturnyj ''zapas'' reaktivnosti,esli sistema imeet otricatel'nyj temperaturnyj kojefficient; 6) rashody po izgotovleniju znachitel'no nizhe, chem dlja jelektromehanicheskih sistem. Provedena ocenka koncepcii SMCh, v tom chisle bylo osushhestvleno stroitel'stvo pro- totipnyh modelej i proverka gidravlicheskih i jadernyh harakteristik. Izuchalis' dva tipa: propuskajushhie ''sterzhni'' (tolshhina 2 srednih svbbodnyh probega) i otrazhajushhie ''sterzhni'' (tolshhina 4 srednih svobodnyh probega). Dlja oboih tipov mozhno poluchit' priemlimye gidravlicheskie i jadernye harakteristiki. Obosnovana vozmozhnost' upravlenija reaktorami nizkoj moshhnosti s pomoshh'ju propuskajushhih ili otrazhajushhih upravljajushhih ' sterzhnej''. Dalee bylo pokazano, chto SPCh obladajut horoshimi regulirujushhimi svojstvami, kotorye mozhno rasschitat' standartnymi metodami. V sluchae bol'shoj moshhnosti i vysokoj temperatury neobhodima dopolnitel'naja informacija otnositel'no harakteristik materiala chastic. Bol'shoe preimushhestvo SPCh zakljuchaetsja v vozmozhnosti formirovanija osevogo potoka libo putem ispol'zovanija chastic razlichnoj velichiny i pogloshhenija, libo zhe putem.sootvetstvujushhego formirovanija oblasti poperechnogo sechenija SPCh. (author)

  14. Aspects of Reactor Physics Research at the Victoria University of Manchester; Quelques Aspects des Experiences de Physique des Reacteurs a l'Universite Victoria de Manchester; Aspekty ehksperimental'nykh issledovanij po fizike reaktorov v universitete viktorii v manchestere; Trabajos de Fisica Experimental con Reactores Efectuados en la Universidad Victoria de Manchester

    Harris, M. J.; Walton, D. G. [Victoria University of Manchester (United Kingdom)

    1964-02-15

    fiziki reaktorov s ogranichennymi sredstvami. Postroena nedorogaja jeksponencial'naja ustanovka prirodnyj uran-obychnaja voda. Ee mehanicheskaja konstrukcija daet vozmozhnost' dobit'sja znachitel'noj gibkosti, tak chto, naprimer, znachitel'no oblegchajutsja izmerenija v napravlenii, parallel'nom i perpendikuljarnom toplivnym sterzhnjam. Osushhestvljaetsja programma stacionarnyh izmerenij. Namechaetsja v obshhih chertah rabota na budushhee, vkljuchajushhaja izmerenija tonkoj struktury, vlijanie pustot i issljodovanija impul'snyh nejtronov. (author)

  15. Scanning Techniques for Brain-Tumour, Localization; Techniques Scintigraphies pour la Iocalisation des Tumeurs Cerebrales; Tekhnika skennirovaniya pri opredelenii lokalizatsii opukholej mozga; Tecnicas Centelleograficas para la Localizacion de Tumores Cerebrales

    Duggan, M. H.; Brice, J.; Jones, E.; Mallard, J. R.; Myers, M. L. [Department Of Medical Physics, Postgraduate Medical School, Hammersmith Hospital, London (United Kingdom)

    1964-10-15

    vstrechajushhiesja geometricheskie iskazhenija. Oni voznikajut i v otnoshenii bulavochnyh i matrichnyh apertur nabljudenija. Obsuzhdajutsja uluchshenija, dostignutye v rezul'tate rjada izmenenij, napravlennyh na ustranenie zavisimosti razmera izobrazhenija ot jenergii gamma-luchej. Analiz dannyh skennirovanija mozga predstavljaet trudnosti, esli skorost' scheta v issleduemoj oblasti tol'ko nemnogo vyshe, chem'v okruzhajushhej tkani. ''Normal'naja'' diagramma skorosti scheta dlja golovy byla opredelena na osnovanii razdelenija skennogrammy na rjad oblastej, kotorye javljajutsja priblizitel'no jekvivalentnymi anatomicheski u rjada pacientov i putem izmerenija skorosti scheta v predelah scentiskennograficheskih otmetok v kazhdoj oblasti. Pojetomu ljubuju patologicheskuju skennogrammu mozhno sravnivat' s jetoj diagrammoj. Pri takom analize pribegajut k schetno-vychislitel'nym metodam. Ispol'zovanie metoda postojannogo usrednenija takzhe imeet znachenie dlja uluchshenija vizual'nogo nabljudenija otklonenij ot normy vblizi granic detektirovanija v podvizhnyh detektornyh sistemah. Rassmatrivajutsja vozmozhnosti primenenija s jetoj cel'ju mnogokanal'nyh analizatorov i ispol'zovanija v to zhe vremja novogo cennogo vosproizvodjashhego ustrojstva kak dlja podvizhnoj, tak i stacionarnoj sistem. (author)

  16. Techniques Which Aid in Quantitative Interpretation of Scan Data; Methodes Facilitant l'Interpretation Quantitative des Scintigrammes; Metody, oblegchayushchie kolichestvennuyu interpretatsiyu dannykh skennirovaniya; Tecnicas Que Facilitan la Interpretacion Cuantitativa de los Datos Centelleograficos

    Charleston, D. B.; Beck, R. N.; Eidelberg, P.; Schuh, M. W. [Argonne Cancer Research Hospital, Chicago, IL (United States)

    1964-10-15

    jelektronnyh pereschetnyh us troj stv . Neposredstvennyj i chrezvychajno poleznyj metod ispol'zovanija generatora besporjadochnyh impul'sov sluzhit dlja nanesenija kalibrovannyh ustupchato-klinoobraznyh otmetok, kotorye proektirujutsja na plenku t em zhe samym istochnikom sveta, kotoryj ispol'zuetsja vo vremja skennirovanija; jeto daet vozmozhnost' prosmotrovoj golovke sravnivat' plotnost' obluchenija izuchaemyh zon skennirovanija s analogichnymi zonami na klinoobraznyh otmetkah, kotorye kalibrovany neposredstvenno v edinicah skorosti scheta. Vspomogatel'noe oborudovanie, kak naprimer mnogokanal'nyj analizator, ispol'zuemyh pri sposobe mnozhestvennyh schetov, pozvoljaet nakopljat' cifrovuju informaciju dlja poluchenija 'obshhego chisla schetov na strochku skennirovanija'' dlja kazhdogo shaga pokazatelja. Bylo provedeno skennirovanie melkih zhivotnyh, kotoroe pozvolja et nakopljat' dannye i davat' ''chislo schetov na strochku skennirovanija'' dlja kazhdogo shaga pokazatelja. Jeto da et tochnoe kolichestvennoe izmerenie raspredelenija aktivnosti v tele zhivotnogo, a takzhe izobrazhaet profil' aktivnosti, analogichnyj tomu, kotoryj poluchaetsja pri shhelevom linejnom skennirovanii. Tot zhe samyj metod mnozhestvennyh schetov primenja etsja idale e putem nakoplenija chislennoj informacii dlja poluchenija {sup c}hisla schetov na edinicu ploshhadi{sup .} Dlja kazhdoj strochki skennirovanija kazhdogo shaga pokazatelja poluchaetsja otdel'naja krivaja profilja. Jeto daet vozmozhnost' opredeljat' skorost' scheta ili stroit' sootvetstvujushhij profil' dlja kazhdoj ploshhadi. Pokazanija skennirovanija s usileniem kontrasta ili beznego, a takzhe s ''otstavaniem'' ili bezne go v integrirujushhem konture diagrammy skennirovanija s razlichnymi razmerami i formami pjaten byli polucheny v identichnyh statisticheskih uslovijah pri pomoshhi m no go kratnogo skennirovanija fantoma odnim detektorom . Neposredstvennoe sravnenie jetih pokazanij sovmestno s metodom sostavlenija grafikov {sup c

  17. Fast Plasma from a Coaxial Gun; Plasma Rapide Produit par un Canon Coaxial; Bystraya plazma iz koaksial'nogo inzhektora; Produccion de Plasma Rapido Mediante un Inyector Coaxial

    Marshall, J.; Henins, I. [Los Alamos Scientific Laboratory, Los Alamos, NM (United States)

    1966-04-15

    vzaimodejstvija radial'nogo toka plazmy i magnitnogo polja toka, protekajushhego vdol' central'nogo jelektroda. Vozmushhenie toka dvizhetsja cherez inzhektirovannyj gaz v napravlenii sopla inzhektora so skorost'ju Tilde-Operator 2,5 x 10{sup 7} sm/sek., akkumuliruja za soboj jenergiju magnitnogo polja i kineticheskuju jenergiju plazmy. Inzhektor so svoej akkumulirovannoj jenergiej vypolnjaet funkciju generatora moshhnosti s nizkim impedansom, vybrasyvajushhego v vakuum za predely sopla struju toka, kotoraja javljaetsja istochnikom bystroj plazmy ( Tilde-Operator 5 x 10{sup 17} dejtronov, Tilde-Operator 10{sup 8} sm/sek). V jetih jeksperimentah issledujutsja struja toka i plazma, kotoruju ona obrazuet. Mehanizm uskorenija slozhen i nedostatochno izuchen, odnako v obshirnoj serii jeksperimentov poluchena znachitel'naja informacija. Dlja diagnostiki ispol'zovalis' sledujushhie metody: vneshnie odnovitkovye diamagnitnye zondy, pojasa Rogovskogo vnutri vakuumnoj kamery, jelektricheskie zondy, vneshnie emkostnye zondy, magnitnyj i jelektrostaticheskij analiz chastic, spektroskopija, fotografija svetovyh izobrazhenij na misheni, vremja proleta s napravljajushhim polem i bez nego, d-d nejtrony iz ob{sup e}ma plazmy i dr. Skladyvaetsja predstavlenie, chto pered soplom inzhektora proishodit slozhnyj jelektromagnitnyj process- Process uskorenija zavisit ot nizkoj plotnosti gaza tam v protivopolozhnost' vysokoj plotnosti vnutri prozhektora. Bystraja plazma v osnovnom poluchaetsja iz gaza , adsorbirovannogo na jelektrodah. Jeto vyzyvaet neobhodimost' v chistom vakuume s tem, chtoby izbezhat' zagrjaznenija sil'no ionizirovannymi bystrymi ionami primesej (C{sup 5+}, 10{sup 8} sm/sek). Material jelektroda isparjaetsja, odnako ne vyzyvaet sil'nogo zagrjaznenija, poskol'ku ono pojavljaetsja pozdno. Vysokoe naprjazhenie, uskorjajushhee iony, svjazano s bystrym rasshireniem v vakuum magnitnogo potoka, vmorozhennogo v struju. Bystraja plazma imeet uzkoe konicheskoe raspredelenie s provalom v centre

  18. Strain Dependence of the Frequencies and the Thermal Expansion of the Hexagonal Close-Packed Lattice; Variations, en Fonction de la Deformation, des Frequences et de la Dilatation Thermique du Reseau a Structure Hexagonale Compacte; Zavisimost' chastot i teplovogo rasshireniya geksagonal'noj reshetki s plotnoj upakovkoj ot napryazheniya; Variacion de las Frecuencias y de la Dilatacion Termica de la Red Hexagonal Compacta en Funcion de la Deformacion

    Srinivasan, R.; Ramji Rao, R. [Physics Department, Indian Institute of Technology, Madras (India)

    1965-04-15

    {gamma}'' Para tres pares de valores de m y n. Se ha comprobado que {gamma}' = {gamma}'' y que el limite superior de temperatura {gamma}{sub {infinity}} mayor en 0,3, aproximadamente, que el limite inferior de temperatura{sup .} Esta diferencia cuya magnitud parece ser independiente de los valores de m y n, disminuira probablemente al tener en cuenta la interaccion de atomos vecinos mas alejados. Los datos teoricos se comparan con los resultados experimentales obtenidos en el caso del magnesio. (author) [Russian] Nedavno bylo izmereno anizotropnoe teplo voe rasshirenie nekotoryh geksagonal'nyh metallov. Dlja razrabotki teorii anizotropnogo teplovogo rasshirenija geksagonal'noj reshetki s plotnoj upakovkoj neobhodimo issledovat' zavisimost' chastot geksagonal'noj reshetki s plotnoj upakovkoj ot naprjazhenija. Rassmatrivalas' geksagonal'naja reshetka s plotnoj upakovkoj s central'nym vzaimodejstviem s bli- a b zhajshim sosednim atomom v vide Empty-Set = -a/{gamma}{sup m} + b/{gamma}{sup n} Ispol'zuemymi naprjazhenijami javljajutsja 1) prodol'noe rasshirenie #Greek Lunate Epsilon Symbol#' vdol' osi z; i 2) ravnomernoe vozdushnoe rasshirenie {zeta} vdol' osnovnoj ploskosti. Oni javljajutsja sootvetstvujushhimi naprjazhenijami v teorii teplovogo rasshirenija,i ih preimushhestvom javljaetsja to, chto oni ne vyzyvajut smeshhenij mezhdu reshetkami. Byli razrabotany parametry Grjunajzena {gamma}'{sub i} = - Partial-Differential log{omega}{sub i}/ Partial-Differential #Greek Lunate Epsilon Symbol#' and {gamma}'{sub i}' = - Partial-Differential log{omega}{sub i}/ Partial-Differential {zeta} Dlja volnovyh vekto- J rov, idushhih vdol' opredelennyh simmetrichnyh napravlenij. Bylo ustanovleno, chto jeti parametry dlja akusticheskih vetvej sil'no zavisjat ot napravlenija i sil'no kolebljutsja. Odna iz poperechnyh akusticheskih vetvej v osnovnoj ploskosti imeet otricatel'noe znachenie {gamma}' dlja ljubyh znachenij ship. Byla opredelena zavisimost' momentov {mu}{sub 2}, {mu}{sub 4} i {mu

  19. New Frontiers for Non-Destructive Testing in the Nuclear Age; Perspectives des Essais Non Destructifs a l'Ere Nucleaire; ''Novye rubezhi'' nedestruktivnykh ispytanij v yadernyj vek; Nuevas Posibilidades de los Ensayos No Destructivos en la Era Nuclear

    Ballard, D. W. [Sandia Laboratory Albuquerque, NM (United States)

    1965-10-15

    aplicarlas a la produccion si se quiere lograr un mayor nivel de seguridad en el empleo-del equipo nuclear. (author) [Russian] Posle vtoroj mirovoj vojny kolossal'no vozroslo chislo metodov nedestruktivnyh ispytanij chto mozhno v znachitel'noj stepeni ob'jasnit' tem, chto v jadernoj promyshlennosti pred{sup j}av- ljajutsja vse bolee strogie trebovanija k kachestvu i nadezhnosti oborudovanija. Slozhnost' sis- temy i obshhie rashody, svjazannye s povrezhdenijami, nastol'ko vozrosli, chto sushhestvuet na stojatel'naja neobhodimost' v razrabotke bolee jeffektivnyh metodov nedestruktivnyh ispy- tanij, a takzhe v ih ispol'zovanii na vsem protjazhenii proizvodstvennogo cikla. V nastojashhee vremja znachitel'no rasshirjajutsja vozmozhnosti primenenija horosho izvest- nyh metodov ispytanij, naprimer s pomoshh'ju radiografii, ul'trazvuka i jelektromagnitnyh kolebanij, dlja udovletvorenija vse vozrastajushhih trebovanij tehnicheskogo usovershenstvova- nija. Odnovremenno razrabatyvajutsja novye principy ispytanij special'no dlja togo , chto- by proverit' te trebovanija, kotorye pred{sup j}avljajutsja k staticheskim i dinamicheskim harakte- ristikam. Jeti bystrodejstvujushhie metody s vysokoj razreshajushhej sposobnost'ju, javljaju- shhiesja poistine ''novymi rubezhami'' nedestruktivnyh ispytanij, polozheny v osnovu nasto- jashhej raboty. V chislo novejshih metodov, kotorye rassmatrivajutsja v doklade, vhodit ispol'zovanie infrakrasnyh luchej dlja opredelenija prochnosti svarnyh soedinenij. Rassmatrivaetsja ispy- tanie struktur metodom kinoradiografii vo vremja vibracionnogo ispytanija s cel'ju izuche- nija ih dinamicheskogo povedenija. Drugoj oblast'ju, kotoraja imeet iskljuchitel'no vazhnoe zna- chenie dlja poluchenija nadezhnogo reaktornogo topliva, javljaetsja jeffektivnoe nahozhdenie mesta techi. Rassmatrivaetsja metod proverki zakljuchennyh v o''olochku komponentov, pri kotorom ispol'zuetsja radioaktivnyj gaz i kotoryj pozvoljaet izmerjat' skorosti utechki, sostavlja- jushhie 10

  20. Pulsed and Static Neutron Measurements in Light-Water and Heavy-Water Exponentials; Mesures par les Methodes Pulsee et Statique dans les Ensembles Exponentiels a Eau Legere et a Eau Lourde; Izmerenie impul'snykh i staticheskikh nejtronov v ehksponentsial'nykh ustanovkakh s obychnoj i tyazheloj vodoj; Mediciones por los Metodos Pulsados y Estaticos en Conjuntos Exponenciales de Agua Ligera y Agua Pesada

    Parkinson, T. F.; Perez, R. B.; Fry, D. N.; Hartley, R. H.; Smith, S. P.D.; Diaz, N. J. [University of Florida, Gainesville, FL (United States)

    1964-04-15

    kotorogo mozhno vyvesti k' , primenjalsja metod impul'snyh nejtronov. Odnako dlja ustanovlenija pravomernosti impul'snogo metoda neobhodimo proizvesti sravnenie mezhdu impul'snym i staticheskim metodami. My vypolnili takie izmerenija s zamedliteljami iz H{sub 2}O i D{sub 2}O v sistemah s otrazhatelem i bez takovogo. Dlja jeksperimentov ispol'zovalsja bak diametrom 1 m. Dlja korreljacii izmerennyh postojannyh raspada s sootvetstvujushhimi-parametrami sistemy, ispol'zovalas' modificirovannaja odnogruppovaja teoreticheskaja model' (imenuemaja v dal'nejshem model'ju A). Tak, {lambda} vyrazhaetsja prostym otnosheniem {lambda}{sub 0}, k{sub {infinity}} {tau}, L{sup 2} i B{sup 2}, gde B{sup 2} udovletvorjaet kriticheskomu ravneniju dvuh zon. Vychislitel'naja shema vkljuchaet opredelenie snachala znachenija postojannoj raspada {lambda} s posledujushhej interaciej do teh por, poka ne budet najdeno znachenie V', sootvetstvujushhee kriticheskomu uravneniju i granichnym uslovijam . Byli oprobovany takzhe dve drugie modeli: Model' V-dvuhzonnaja odnogruppovaja sistema, v kotoroj B{sup 2}{sub g} v funkcii vlijanija Fermi prinimaetsja kak geometricheskij laplasian jekvivalentnoj sistemy bez otrazhatelja s otrazhatel'noj dobavkoj. Model' C -dvuhgruppovaja sistema bez otrazhatelja s otrazhatel'noj dobavkoj. Sravnenie raschetnyh i jeksperimental'nyh postojannyh raspada pokazyvaet, chto tol'ko model' A daet udovletvoritel'noe sovpadenie. Mozhno sdelat' sledujushhie vyvody: 1. Prisutstvie otrazhatelja sil'no vlijaet na fiziku impul'snoj sistemy Metod predpolozhenija otrazhatel'noj dobavki ne vsegda cenen. 2. Znachenie postojannoj raspada {lambda} ochen' chuvstvitel'no k predpolagaemomu znacheniju verojatnosti izoezhanija utechki oystryh nejtronov. Jeksperimenty pokazali, chto dlja nebol'shih geterogennyh sborok k mozhno opredelit' metodom impul'snyh nejtronov. V nastojashhee vremja provodjatsja raboty po pustotelym uranovym sterzhnjam, kotorye pozvoljajut imitirovat' organicheskie

  1. Role of Exchange Equilibria in Structural Chemistry; Role des Equilibres d'Echange en Chimie Structurale; Rol' ravnovesiya obmena v strukturnoj khimii; Papel de los Equilibrios de Intercambio en Quimica Estructural

    Van Wazer, J. R.; Moedritzer, K. [Monsanto Company, St. Louis, MI (United States)

    1965-10-15

    partes de estructuras moleculares. Ademas, se han estudiado cuantitativamente los equilibrios entre estructuras ciclicas y aciclicas. El hincapie que la quimica estructural hace sobre los compuestos del carbono (como lo pone de manifiesto la division de la'quimica descriptiva en las categorias e inorganica) se atribuye al hecho de ser sumamente lentas las reacciones de intercambio donde intervienen enlaces C-C o uniones entre carbono y cualquier otro atomo que no posea orbitales de enlace libres en niveles bajos (por ejemplo: Si, Ge, N, P, As, O, S, Se, F, Cl, Br). No obstante ello, hay vastos dominios de la quimica inorganica que no han podido describirse dado que las moleculas sufren reacciones de intercambio tan rapidas que resulta imposible separarlas. Sin embargo, se las puede identificar y valorar por metodos ffsicos (tales como la resonancia magnetica nuclear) con constantes de tiempo pequenas, a condicion de someter los datos obtenidos a un tratamiento matematico adecuado, siendo este tratamiento de una complejidad que justifica el empleo de una calculadora rapida [6,16]. Los topicos expuestos se ejemplifican [2, 12, 24, 28] mediante sistemas especificos seleccionados entre. los trabajos mas recientes del autor. Ademas de los estudios de equilibrio, se presta atencion a la cinetica [26, 27] de los procesos de intercambio. Se presentan varios teoremas generales que permiten predecir los tipos y cantidades de productos [6, 18]. (author) [Russian] Hotja v proshlom znachitel'- naja dolja usilij v oblasti reakcij obmena byla posvjashhena razboru monofunkcional'nyh zame- stitelej v polifunkcional'nom atome ili ego chasti, slozhnye molekuly mogut takzhe pod- vergat'sja obmenu chastej i davat' takim obrazom ravnovesnoe raspredelenie razlichnyh molekuljarnyh razmerov i form. Ispol'zovanie jadernogo magnitnogo rezonansa (JaMR) s vysokim razresheniem dlja issledovanija takih ravnovesnyh smesej slozhnyh soedinenij bylo opisano v 1964 i 1965 g g . vo mnogih dokladah

  2. Survey of Pulsed Neutron Source Methods for Multiplying Media; Methodes des Neutrons Pulses Pour l'Etude des Milieux Multiplicateurs; Obzor metodov s ispol'zovaniem istochnikov impul'snykh nejtronov dlya razmnozhayushchej sredy; Estudio Panoramico de los Metodos de Empleo de Fuentes de Neutrons Pulsados en Medios Multiplicadores

    Garelis, E. [General Electric Company, Vallecitos Atomic Laboratory, Pleasanton, CA (United States)

    1965-10-15

    . Jeksponencial'nyj raspad, jeksp (-{alpha}t) , funkcii Grina daet prostranst- venno nezavisimuju postojannuju raspada mgnovennyh nejtronov. Obsuzhdajutsja metody, s pomoshh'ju kotoryh vyvoditsja reaktivnost' iz al'fa-izmerenija, naprimer izmerenie zapaz- dyvajushhej kriticheskoj al'fa i poslednij metod (k{beta}/ Script-Small-L ). Izuchajutsja osnovnye vidy obrabotki modeli v svete teorii s istochnikom impul'snyh nejtronov, kotorye razrabotany dlja modeli (k{beta}/ Script-Small-L ). Rassmatrivajutsja oslozhnenija, svjazannye s teoriej istochnika impul'snyh nejtronov dlja poluchenija tochnyh postojannyh raspada i sootvetstvujushhih dannyh dlja analiza impul'snyh sistem. Rassmatrivaetsja jeksperimental'naja rabota, kotoraja pokazyvaet preimushhestva, a takzhe nedostatki metoda (k{beta}/ Script-Small-L ). Obsuzhdaetsja takzhe ispol'zovanie metoda psevdosluchajnogo otveta impul'sa s kor- reljaciej mezhdu vhodom i vyhodom dlja opredelenija funkcii Grina na razmnozhajushhej sborke. Pokazano, chto informacija, poluchennaja psevdosluchajnym metodom, javljaetsja identichnoj toj, kotoraja poluchena v rezul'tate povtornogo impul'snogo metoda. Takim obrazom, jeto delaet vozmozhnym primenjat' metodiku, razrabotannuju dlja povtorenija metoda psevdo-sluchajnosti. (author)

  3. Electron-Exchange Reactions of Aromatic Molecules; Echanges d'Electrons de Molecules Aromatiques; Reaktsii ehlektronnogo obmena aromaticheskikh molekul; Reacciones de Intercambio Electronico en Moleculas Aromaticas

    Malachesky, P. A.; Miller, T. A.; Layloff, T.; Adams, R. N. [University of Kansas, Lawrence, KS (United States)

    1965-10-15

    'shoe kolichestvo informacii otnositel'no skorosti mehanizma processov neorganicheskogo obmena jelektronov. V protivopolozhnost' jetomu chisto organicheskim sistemam udeljalos' dovol'no neznachitel'noe vnimanie. Skorost' gomogennogo jelektronnogo obmena (k{sub 0bm})i geterogennye konstanty skorosti dlja jelektrodnoj reakcii (k{sub jel}) byli izmereny lish' dlja neskol'kih ugle- vodorodov . Bylo izmereno k{sub 0bm} dlja razlichnyh aromaticheskih sistem, v tom chisle uglevodorodov, hinonov i nitrosoedinenij. Jeti izmerenija byli provedeny posredstvom jelektronnogo para- magnitnogo rezonansa (EPR) s perenosom izmerenij na smesi radikal'nyh ionov i ih mate- rinskih soedinenij. Nam takzhe udalos' izmerit' k0bm s takoj tochnost'ju, kotoraja pozvo- ljaet obnaruzhit' nebol'shie razlichija, vyzvannye, verojatno; molekuljarnoj strukturoj i sre- doj. Uglevodorodnye sistemy, podobnye antracenovomu/antracenovomu anionu, javljajutsja ves'ma bystrymi pri velichine k{sub 0gM} priblizitel'no 10{sup 8}-10{sup 9} litr mol{sup -i} sek{sup -1}. Nekotorye zame- shhennye aromaticheskie soedinenija, podobnye hinonam i nitrilam, takzhe javljajutsja ves'ma bystrymi. Odnako, kogda imeetsja sil'naja funkcija jelektronnogo akceptora, podobno nitro- gruppe v nitrobenzole, velichina k{sub 0gM} sokrashhaetsja na faktor 10. Predstavljaetsja vozmozhnym korrelirovat' izmenenija v k{sub obm} v serijah nitrobenzola s pomoshh'ju plotnosti neparnyh jelek- tronov po konstantam svjazi N{sup 14} spektra EPR. Krome togo, nitroaromaticheskie serii obna- ruzhivajut ochen' bol'shie razlichija v znachenijah k{sub 0b} m s rastvorjajushhej sistemoj. Jeti izmene- nija mozhno korrelirovat' blagodarja nedavnim issledovanijam jeffekta sol'vatacii na sverh- tonkie konstanty svjazi. V poslednee vremja Markus rassmotrel teoriju himicheskogo i jelektrohimicheskogo pere- nosa jelektronov i predlozhil korreljacii mezhdu znachenijami k{sub obm} i k{sub jel}. Nami special'no byl izmeren kjel dlja sistemy nitrobenzola v uslovijah, kotorye

  4. Economic Criteria Applied to Nuclear Materials Management; Criteres Economiques Applicables a la Gestion des Matieres Nucleaires; Ehkonomicheskie kriterii, primenyaemye pri kontrole i uchete yadernykh materialov; Criterios Economicos Aplicados a la Administracion de Materiales Nucleares

    Shelley, W. J.; Kuehn, M. N. [Mallinckrodt Chemical Works, St. Charles, MS (United States)

    1966-02-15

    , primenjaemye pri kontrole i uchete jadernyh materialov. V celjah samogo racional'nogo kontrolja i ucheta jadernyh materialov postojanno proverjali i peresmatrivali proceduru, praktiku i metody kontrolja, a takzhe kadrovye voprosy. S cel'ju obespechenija togo, chtoby optimal'nye rashody byli sbalansirovany s neobhodimymi potrebnostjami kontrolja za jadernymi materialami, byli razrabotany nekotorye obshhie pravila. Ochen' vazhno opredelit' dejstvitel'nye potrebnosti v registracii i vydache svedenij. Dejstvitel'naja jekonomija dostigaetsja za schet vozlozhenija na odnu gruppu otvetstvennosti za kontrol' i uchet jadernyh materialov, za proizvodstvennyj kontrol' i rashody. Takomu personalu nuzhno okazyvat' doverie. Uchityvaja vazhnost' raboty, jetot personal dolzhen projti tshhatel'nuju podgotovku. Lica, nesushhie otvetstvennost' za kontrol' i uchet jadernyh materialov, dolzhny postojanno sledit' za malejshimi otklonenijami ot norm povedenija i harakteristik personala, za normal'nym ispol'zovaniem processov, sistem, procedur i metodov. Tol'ko blagodarja takomu otnosheniju i zhelaniju proizvodit' peresmotr v celjah uluchshenija, mozhno dobit'sja optimal'nogo sbalansirovanija rashodov i potrebnostej. (author)

  5. Renal Scintiscanning with Hg{sup 209}-Neohydrin in Urologic Diseases; Scintigraphy du Rein dans les Maladies des Voies Urin Aires au Moyen de Neohydrine Marquee avec {sup 203}Hg; Stsintillyatsionnoe skennirovanie pochek s pomoshch'yu neogidrina,mechennogo Rtut'yu-203, pri urologicheskikh zabolevaniyakh; Exploracion Centelleografica del Rinon con Neohydrina - {sup 203}hg en las Afecciones Urologicas

    Bollini, V.; Tori, G. [Radiology Institute of the University of Bologna (Italy)

    1964-10-15

    determinar una disminucion de la funcion renal y a diferenciar los casos unilaterales de los bilaterales. Asi, la centelleografia del rinon constituye al parecer una tecnica clinica de gran utilidad, especialmente si se combina con el examen radiologico por medios tradicionales (urogtafia, pielografia ascendente, retroneumoperitoneo, tomografia, aorto- grafia, etc.). (author) [Russian] Dlja scintilljacionnogo skenirovanija pochek ispol'zovalsja neogidrin, mechennyj rtut'ju-203. Byl primenen jaderncj Chikagskij izotopnyj skenner tipa 1700 s kristallom 5 h 5 sm i kollimator ''Hanikoum'' s fokusnym rasstojaniem 7 sm. Obychno scintigrammy registrirujutsja odnovremenno na bumage i na fotoplenke. Neogidrin, mechennyj rtut'ju-203, primenjaetsja obychno v dozah 120 - 160 mkkjuri (okolo 2 mkkjuri/kg). Skennirovanie nachinajut spustja 2 chasa posle in{sup e}kcii i prodolzhajut 40 - 50 minut. Selektivnoe skoplenie mechenogo neogidrina v korkovom sloe pochek daet vozmozhnost' poluchit' graficheskoe izobrazhenie obeih pochek i opredelit' ih polozhenie, orientaciju i formu, a takzhe gomogennost' aktivno funkcionirujushhej parenhimy. V nekotoryh sluchajah byli provedeny avtoradiograficheskie issledovanija porazhennyh pochek posle hirurgicheskogo udalenija. S pomoshh'ju takogo metoda mozhno diagnoscirovat' kak vrozhdennye, tak i priobretennye anomalii polozhenija i orientacii. Chto kasaetsja formy, to granicy pochek mozhno opredelit' tem tochnee, chem luchshe funkcioniruet pochka. Takie tehnicheskie aspekty, kak shirina kristalla, tip kollimatora (fokal'naja ploskost' kotorogo dolzhna prohodit' cherez srednjuju poperechnuju ploskost' pochek) i doza, kotoraja ne dolzhna byt' slishkom vysokoj ili slishkom maloj, sostavljajut sushhestvennoe uslovie dlja pravil'nogo graficheskogo vosproizvedenija ochertanij pochek. Narushenie dejatel'nosti kanal'cev v parenhime opredeljaetsja blagodarja narusheniju pogloshhenija radioaktivnosti. Polozhenie, razmery i forma takih defektov pogloshhenija

  6. Design and Experimental Evaluation of an Electromagnetic Acceleration System for Fast Safety Rods; Etude Theorique et Experimentale d'un Mecanisme Electromagnetique d'acceleration pour des Barres de Securite; Proektirovanie i ehksperimental'naya otsenka ehlektromagnitnoj sistemy uskoreniya dlya avarijnykh sterzhnej bystrogo dejstviya; Proyecto y Estudio Experimental de un Sistema Electromagnetico de Aceleracion para Barras Rapidas de Seguridad

    Dosch, P.; Kraus, H. -J.; Uhrig, H. [Kernreaktor Bau- und Betriebs-Gesellschaft m.b.H., Karlsruhe, Federal Republic of Germany (Germany)

    1964-06-15

    rapida de seguridad para un conjunto rapido de potencia nula (SNEAK). Se esta ensayando un prototipo de dicha barra. Los resultados obtenidos hasta ahora han sido muy satisfactorios. (author) [Russian] Sistema avarijnoj zashhity reaktora dolzhna dej stv ov at' s minimal'noj za d erzh k oj , esli ona prednaznachena dlja kontrolja ochen' bystryh otklonenij reaktivnosti. V jelektronnyh chastjah sistemy avarijnoj zashhity mozhno ochen' legko dobit'sja bystrogo srabatyvanija, t o gd a kak sokrashhenie vremeni m ehanicheskogo vysvobozhdenija avarijnogo sterzhnja javljaetsja trudnoj za d a ch ej. Bole etshhatel'nye issledovanija pokazyvajut, chto pomimo nebol'shogo vremeni vysvobozhdenija, preimushhestvo daet vysokaja pervonachal'naja skorost' sterzhnja. Pri odinakovom kolichestve vremeni, zatrach i v a emom na v v edenie st erzh n ja , sterzhni s ravnomernoj skorost'ju n emn ogo p revoshodjat sterzhni s ravnomernym u skoreiem . - Na osnovanii jetih soobrazhenij mozhno schi t a t' , chto impul'snoe u sk oren ie ja vlja etsja pravil'nym metodom vvedenija avarijnyh sterzhnej dlja ustranenija bystryh otklonenij r e aktivnosti, tak kak jeto daet nebol'shuju zaderzhku i obespechivaet vysokuju pervonachal'nuju skorost'. Ustanovleno, chto v avarijnyh sterzhnjah mozhno primenit' jelektromagnitnyj impul'snyj g en er ator. On imeet sledujushhie preimushhestva: a) nebol'shoe kolichestvo komponentov prostoj i prochnoj konstrukcii, kotorye mogut byt' legko vkljucheny v avarijnyj sterzhen', a takzhe mogut byt' skonstruirovany dlja u slovij, sushhestvujushhih okolo aktivnoj zony (vysokie urovni temperatury i izluchenija); b) jen ergi ja , privodjashhaja v dvizhenie sterzhni, akkumuliruetsja v jelek trok on den satore i p o jet om u takzhe mozhet byt' ispol'zovana v sluchae prekrashhenija jenergopitanija; v) konstrukciju legko mozhno prisposobit' k tomu, chtoby ona mogla svobodno i be sp r e pjatstvenno padat' v sluchae prekrashhenija impul'sov. V doklade opisyvajutsja rezul

  7. Comparison of Alkali Plasma Loss Rates in a Stellarator and in a Toroidal Device with Minimum Mean-B Properties; Comparaison des Taux de Perte d'un Plasma Alcalin dans un Stellarator et dans un Appareil Toroidal Ayant des Proprietes de B Moyen Minimum; Comparaison des Taux de Perte d'un Plasma Alcalin dans un Stellarator et dans un Appareil Toroidal Ayant des Proprietes de B Moyen Minimum; СРАВНЕНИЕ СКОРОСТЕЙ ПОТЕРЬ ЩЕЛОЧНОЙ ПЛАЗМЫ В СТЕЛЛАРАТОРЕ И В ТОРОИДАЛЬНОЙ УСТАНОВКЕ С МИНИМУМОМ СРЕДНЕГО В; Comparacion de las Velocidades de Perdida de Plasmas Alcalinos en un Stellarator y en un Aparato Toroidal con Propiedades de B Medio Minimo

    Eckhartt, D.; Von Gierke, G.; Grieger, G. [Max-Planck-Institut fuer Physik und Astrophysik, Munich, Federal Republic of Germany (Germany)

    1966-04-15

    vintovymi obmotkami issledovalos' uderzhanie plazmy s nizkim znacheniem Je pri otsutstvii omicheskih tokov. V rezul'tate jetih jeksperimentov polucheny dokazatel'stva togo, chto poverhnosti postojannogo davlenija skoree sovpadajut s poverhnostjami postojannogo V, chem s magnitnymi poverhnostjami, chto obychno ozhidalos' by dlja stellaratora v magnitogidrodinamicheskom ravnovesii. My postavili takzhe jeksperimenty na stellaratore s dvuhzahodnymi obmotkami, kotorye obespechivajut postojannoe vrashhatel'noe preobrazovanie vseh silovyh linij uderzhivajushhego magnitnogo polja. Dlja obespechenija ravnovesija v stellaratore, v kotorom uderzhivajushhee pole imeet glavnym obrazom azimutal'noe napravlenie, neobhodimy vtorichnye toki, a takzhe makroskopicheskie dvizhenija massy vdol' silovyh linij. Odnako v toroidal'noj ustanovke s azimutal'noj simmetriej s chisto meridional'nym magnitnym polem ravnovesija mozhno dostignut' bez kakih-libo tokov ili makroskopicheskih dvizhenij vdol' V. Krome togo, ustojchivost' otnositel'no zhelobkovyh vozmushhenij na poverhnosti plazmy mozhno obespechit' dlja plazmy s nizkim znacheniem {beta}, ecm {nabla} Contour-Integral d Script-Small-L /B napravleno parallel {nabla}p. My postroili ustanovku s vysheukazannymi svojstvami. Ona sostoit glavnym obrazom iz chetyreh tokonesushhih kol'cevyh provodnikov, pogruzhennyh v plazmu (analogichno sisteme Okava i d r . ) . Provodniki pitajutsja postojannymi tokami s tem, chtoby izbezhat' obrazovanija azimutal'no napravlennyh jelektricheskih polej v plazme. Izuchaetsja uderzhanie plazmy v jetoj ustanovke s pomoshh'ju termicheskoj plazmy shhelochnyh metallov, kotoraja poluchaetsja v rezul'tate kontaktnoj ionizacii. Mozhno vybrat' takie rabochie uslovija, pri kotoryh poteri v plazme v rezul'tate ''klassicheskih'' mehanizmov (stolknovitel'naja diffuzija na stenki i kol'cevye provodniki, poteri chastic na derzhateljah, ob{sup e}mnaja rekombinacija it.d. ) stanovjatsja neznachitel'nymi po sravneniju s bol

  8. Tritium and Autoradiography in Cell Biology; Tritium et Autoradiographie en Biologie Cellulaire; 0422 0440 0438 0414 ; El Tritio 0443 la Tecnica Autorradiografica en Citobiologia

    Taylor, J. H. [Departments of Botany and Zoology, Columbia University, New York, NY (United States)

    1962-02-15

    ADN, cuya actividad disminuye rapidamente cuando la celula se extrae del medio que contiene la timidina tritiada. Por este procedimiento se ha obtenido informacion sobre el mecanismo de duplicacion del ADN, la estructura y reproduccion de los cromosomas, la cinetica de la division celular y, mas recientemente, sobre el regimen y orden cronologico de reproduccion de diferentes cromosomas en el mismo nucleo y de las diferentes partes de un mismo cromosoma. Todos los cromosomas estudiados hasta ahora contienen dos fracciones funcionales de ADN que se distribuyen de manera aproximadamente uniforme durante la reproduccion. Las dos fracciones son desiguales en cierto sentido estructural que limita el tipo de intercambios que pueden producirse entre las cuatro fracciones del cromosoma en reproduccion. Los daios obtenidos sobre la cronologia de esos fenomenos permiten suponer que los cromosomas se reproducen en un orden controlado geneticamente. En la actualidad se procura obtener mas datos sobre el regimen y el mecanismo de control del orden en que se desarrollan los fenomenos, asi como sobre otros procesos conexos, entre ellos la sintesis de proteinas cromosomicas y de otra clase de acidos nucleicos, a saber, los acidos ribonucleicos. (author) [Russian] Poskol'ku tritij izluchaet beta-radiaciju nizkoj jenergii, on predstavljaet soboj naibolee poleznyj izotop, obespechivajushhij vysokuju razreshajushhuju sposobnost' pri radioavtografii. Otnositel'naja rasprostranennost' vodoroda v bol'shinstve biologicheski vazh- nyh veshhestv v sochetanii so sravnitel'no korotkim periodom poluraspada poz- voljaet metit' kletochnye komponenty pri udel'nyh aktivnostjah, kotorye za- chastuju mogut byt' obnaruzheny pri mezhkletochyh razmerah s pomoshh'ju jadernyh jemul'sij. Kletki prikrepljajutsja k steklu razlichnymi citologicheskimi meto- dami, i posle fiksacii mokraja ili zhidkaja fotojemul'sija prikrepljaetsja nepo- sredstvenno k poverhnosti kletki, posle chego ej dajut vozmozhnost

  9. Rapid Estimation of Fast-Neutron Doses following Radiation Exposure in Criticality Accidents: The S{sup 32}(n, p)P{sup 32} Reaction in Body Hair; Prompte Evaluation des Doses de Neutrons Rapides apres une Exposition au Rayonnement a la Suite d'Accidents de Criticite: Reaction {sup 32}S(n, p){sup 32}P dans le Systeme Pileux; 0411 042b 0421 0414 ; Evaluacion Acelerada de Dosis de Neutrones Rapidos Despues de una Irradiacion Consecutiva a un Accidente de Criticidad: La Reaccion {sup 32}S(n, p){sup 32}P en el Pelo

    Petersen, D. F. [Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)

    1965-06-15

    dlja celej predvaritel'noj ocenki trebuetsja priblizitel'no shest' chasov. V rezul'tate provedenija jeksperimentov s ispol'zovaniem chetko opredelennyh spektrov delenija na nejekranirovannoj kriticheskoj sborke postojanno imelas' vozmozhnost' dat' ocenku nejtronnoj dozy v predelah {+-}10% v ramkah jetalonnoj dozimetrii. Bolee togo, opredelennoe anatomicheskoe stroenie obrazcov volos daet vozmozhnost' umen'shit' orientaciju i asimmetriju obluchenija v rezul'tate sravnenija otnositel'nyh udel'nyh aktivnostej obrazcov v razlichnyh chastjah organizma. Opyt raboty vo vremja treh jadernyh avarij v sostojanii kritichnosti, privedshih k zhertvam, pokazal, chto v kazhdom sluchae obluchenie bylo'zametno asimmetrichnym. Tak, v rezul'tate izmenenij soderzhanija R{sup 32} v volosah priobretaetsja cennaja dopolnitel'naja informacija dlja sravnenija so srednimi ocenkami nejtronnogo obluchenija vsego organizma, osnovannymi na izmerenijah soderzhanija Na{sup 24} v krovi. Ocenki vyhoda produktov delenija, osnovannye na metodah deduktivnoj geometrii, v kazhdom sluchae nahodilis' v horoshem soglasii s provedennymi nezavisimo opredelenijami obshhego vyhoda produktov delenija bolee obychnymi analiticheskimi metodami. Dlja bystrogo priblizitel'nogo opredelenija dozy bystryh nejtronov velichina aktivnosti R{sup 32} v rasp/min/g v volosah pri T = 0 pri ljuboj sisteme scheta izvestnoj jeffektivnosti prosto umnozhaetsja na kojefficient 0,49 dlja poluchenija velichiny nejtronnoj dozy v radah, vyrazhennoj v vide ''urovnja sery''. (author)

  10. The Impulse Response of an Exponential Assembly; Reponse d'un Assemblage Exponentiel aux Impulsions; Impul'snaya kharakteristika ehksponentsial'noj sborki; Respuesta de un Conjunto Exponencial a los Impulsos

    Uhrig, R. E. [University of Florida, Gainesville, FL (United States)

    1964-04-15

    {sup -z{sup 2/4}} {sup VDt} {sup {infinity}}{Sigma}{sub m} {sub =} {sub 1} {sup {infinity}}{Sigma}{sub n} {sub =} {sub 1} cos m{pi}x/a cos n{pi}y/b e{sup -VD{gamma}{sup 2mn{sup t}}} (3) Esli rassmatrivajutsja tol'ko chleny uravnenija (A-3) vne dvojnogo slozhenija (t.e. ne uchityvajutsja faktory razmnozhenija i utechki)* to poluchaetsja sledujushhij rezul'tat: 2/ab Square-Root V/{pi}D 1/ Square-Root t e{sup -z{sup 2/4}} {sup VDt} = 4V/ab P(z), (4) gde P (z) javljaetsja gaussovym chlenom raspredelenija formy: P(z) = 1/o Square-Root 2{pi} e{sup -z{sup 2/2{gamma}{sup 2}}} (5) pri zavisimom ot vremeni standartnom otklonenii o = Square-Root 2 VDt. (6) Takim obrazom, impul's teplovyh nejtronov, vvedennyj v ishodnoj punkt, rasprostranjaetsja so vremenem simmetricheski po ploskosti z =o. Odnako izmenenie amplitudy so vremenem v ljubom meste vdol' z pokazyvaet, chto maksimal'naja velichina plotnosti nejtronov ishodit iz ishodnogo punkta s umen'sheniem amplitudy. Hotja razmnozhenie i obratnaja utechka vlijajut na harakteristiki vozmushhenija, jeto rasprostranjaetsja ot istochnika podobno nejtronnym volnam. Rasprostranenie impul'sa teplovyh nejtronov bylo prodemonstrirovano jeksperimental'no v 1962 godu vo Floridskom universitete pri ispol'zovanii impul'snogo istochnika nejtronov i {sup j}ashhika termalizatora{sup .} Na jetot raz byl ispol'zovan metod perekrestnoj korreljacii psevdo-besporjadochnogo dvojnogo (vykljuchenija-vkljuchenija) izmenenija sily istochnika i izmenenija v rezul'tate jetogo plotnosti nejtronov v jeksponencial'noj sborke. Privodjatsja dannye dlja jeksperimentov, provedennyh na sborkah s zamedleniem kak na legkoj, tak i na tjazheloj vode, na kotoryh ispol'zuetsja prirodnyj uran. Obsuzhdajutsja rezul'taty s tochki zrenija poluchennoj teoreticheskoj svjazi i fizicheskih javlenij. Kratko obsuzhdajutsja dejstvitel'nost' ustanovlennyh svjazej i neobhodimost' rassmotrenija bolee vysokih garmonikov dlja razlichnyh raspolozhenij gorjuchego i zamedlitelja. (author)

  11. Motion of Plasmoid in a Curvilinear Magnetic Field; Mouvement d'un Plasmoide dans un Champ Magnetique Curviligne; Dvizhenie plazmennogo sgustka v krivolinejnom magnitnom pole; Movimiento de un Plasmoide en un Campo Magnetico Curvilineo

    Vojcenja, V. S.; Gorbanjuk, A. G.; Onishhenko, I. N.; Safronov, B. G.; Hizhnjak, N. A.; Shkoda, V. V. [Fiziko-Tehnicheskij Institut, AN USSR, Khar' kov, USSR (Ukraine)

    1966-04-15

    N{sup +} umen'shalas' dolja bystryh chastic i srednjaja jenergija ponizhalas' do velichiny 2 Division-Sign 2,5 kjev. Skorost' fronta plotnosti ph ostavalas' neizmennoj, a skorost' fronta plotnosti pg padala do velichiny Tilde-Operator 4 * 10{sup 7} sm/sek. Kolichestvo primesej v bystrom sgustke (v osnovnom iony S{sup ++} i 0{sup ++} ) sostavljalo okolo 5%. Srednjaja jenergija ionov primesej, proshedshih toroidal'noe pole, okazalas' primerno v 2 raza men'she, chem nachal'naja (posle prjamogo solenoida). (author)

  12. Delayed Neutrons and Photoneutrons from Fission Products; Neutrons Retardes et Photoneutrons Emis par des Produits de Fission; 0417 0410 041f 0410 0417 0414 042b 0412 0410 042e 0429 0418 0415 041d 0415 0419 0422 0420 041e 041d 042b 0418 0424 041e 0422 041e 041d 0415 0419 0422 0420 041e 041d 042b 041f 0420 041e 0414 0423 041a 0422 041e 0412 0414 0415 041b 0415 041d 0418 042f ; Neutrones Retardados y Fotoneutrones de los Productos de Fision

    Amiel, S. [Soreq Nuclear Research Centre, Atomic Energy Commission, Yavne (Israel)

    1965-07-15

    nezavisimy ot jenergii bombardirujushhih deljashhihsja nejtronov pri jenergijah do neskol'kih Mjev. V ztom diapazone vyhody nabljudaemoj gruppy, osobenno gruppy dolgozhivushhih predshestvennikov, dostatochno horosho soglasujutsja s massoj delenija i raspredelenijami zarjada, a takzhe s raschetnoj verojatnost'ju ispuskanija nejtronov. Dal'nejshee detal'noe issledovanie predshestvennikov zapazdyvajushhih nejtronov (v chastnosti, v trudnoj oblasti korotkogo perioda poluraspada) trebuet usovershenstvovanija metodov sverhbystrogo radiohimicheskogo otdelenija predshestvennikov (ili izotopnogo razdelenija na linii), a takzhe bystroj nejtronnoj spektroskopii s vysokoj razreshajushhej sposobnost'ju i jeffektivnost'ju. Fotonejtrony, Znanie intensivnosti i spektrov gamma-luchej produktov delenija imeet bol'shoe prakticheskoe znachenie v reaktornoj tehnike, v chastnosti, chto kasaetsja jeffektov nagrevanija gamma-luchami, jekranirovanija i radiacii. Gamma-luchi s jenergiej, bol'shej chem 2,23 i 1,67 Mjev, javljajutsja prichinoj jemissii fotonejtronov iz dejterija i berillija sootvetstvenno i ochen' vazhny dlja izuchenija kinetiki tjazhelovodnyh reaktorov s zamedlitelem iz berillija. Intensivnost' ispuskanija fotonejtronoja posle delenija predstavljaet soboj slozhnyj raspad sootvetstvujushhih nuklidov, ispuskajushhih gamma-luchi v smesi iz cepochki produktov delenija. Obshhie krivye raspada fotonejtroiov iz D{sub 2}O i Be byli razdeleny na 9 grupp s periodom poluraspada v diapazone ot neskol'kih sekund do priblizitel'no 13 dnej. Kazhdaja iz jetih grupp predstavljaet soboj slozhnyj sostav nuklidov. Detal'naja informacija otnositel'no komponentov jetih grupp ochen' vazhna dlja teh reaktorov, v kotoryh mozhet imet' mesto frakcionirovannoe delenie, vlijajushhee na otnositel'nuju gruppovuju rasprostranennost'. Podobnaja informacija sushhestvuet tol'ko v otnoshenii dolgozhivushhih produktov delenija, harakteristiki i vyhod kotoryh horosho izvestny, i rezul'taty jeksperimentov soglasujutsja s

  13. MASURCA, a Fast-Neutron Critical Mock-Up: Operation and Uses; MASURCA. Maquette Critique a Neutrons Rapides. Description Fonctionnelle et Obiectifs; ''MAZURKA'' - kriticheskaya model' na bystrykh nejtronakh. funktsional'noe opisanie i tseli; Descripcion Funcional y Objetivos de la Maqueta Critica de Neutrones Rapidos 'MASURCA '

    Schmitt, A. P.; Storrer, F.; Vendryes, G. [Association CEA-EURATOM, Cadarache (France); Tavernier, G.; Van Dievoet, J. [Societe Belgo-Nucleaire, Bruxelles (Belgium)

    1964-02-15

    i vysotoj 102 mm. Oni razmeshheny v trubah kvadratnogo sechenija s vneshnej storonoj 106 mm i dlinoj porjadka 4 m. Jeti truby nahodjatsja v pod- veshennom sostojanii rjadom drug s drugom. Central'naja chast' podveshennoj plity mozhet prinimat' men'shie truby, chto pozvoljaet sozdavat' aktivnye zony nebol'shih razmerov. Special'nyj podogretyj kontur takzhe mozhet peremeshhat'sja v central'noj chasti ustanovki, chto daet vozmozhnost' izmerjat' kojefficient Dopplera. V doklade daetsja funkcional'noe opisanie ustanovki. Ukazyvaetsja na vozmozhnost' osushhestvlenija modelirovanija aktivnyh zon bystryh reaktorov na okislah (s pomoshh'ju jelementov iz okisi zheleza dlja vvedenija kisloroda) i na karbidah (s pomoshh'ju grafitovyh jele- mentov). Obsuzhdaetsja metod smeshannyh zagruzok, ko.toryj neobhodimo budet primenjat' vvidu opredelennogo kolichestva plutonija, ispol'zuemogo v takih opytah v nastojashhem desja- tiletii, i metodov, kotorye budut primenjat'sja dlja opredelenija osnovnyh nejtronnyh pa- rametrov. V zakljuchenie ukazyvaetsja mesto, kotoroe zanimaet jetot kriticheskij maket sredi os- novnyh fizicheskih issledovanij, svjazannyh s razrabotkoj reaktorov na bystryh nejtronah. V chastnosti, ispol'zovannye jeksperimental'nye sredstva vkljuchali reaktor-istochnik ''Garmonija'', prednaznachennyj dlja razrabotki,metodov izmerenija i dlja obespechenija jeksponenci- al'nyh opytov, a takzhe uskoriteli v kachestve istochnika staticheskih i dinamicheskih nejtronov dlja obespechenija podkriticheskih opytov na bystryh nejtronah. (author)

  14. Turbulent Heating of Plasma by a Direct-Current Discharge; Chauffage Turbulent du Plasma par le Courant d'une Decharge Directe; ТУРБУЛЕНТНЫЙ НАГРЕВ ПЛАЗМЫ ТОКОМ ПРЯМОГО РАЗРЯДА; Calentamiento Turbulento del Plasma por una Corriente de Descarga Directa

    Babykin, M. V.; Gavrin, P. P.; Zavojskij, E. K.; Rudakov, L. I.; Skorjupin, V. A. [Institut Atomnoj Ehnergii Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

    1966-04-15

    , durante la inestabilidad de la corriente. Se ha observado que, en un plasma con turbulencia intensa, el espesor de la capa superficial es considerablemente mayor que c/{omega}{rho}. Se propone una explicacion de este hecho. Se estudia el mecanismo de calentamiento del plasma durante la inestabilidad de la corriente. En la memoria se expone una teoria detallada de este fenomeno. (author) [Russian] V doklade izlagajutsja rezul'taty jeksperimentov po turbulentnomu nagrevu plazmy tokom prjamogo razrjada v lovushke s magnitnymi probkami. Issledovalis' takzhe adiabaticheskoe szhatie nagretoj plazmy i nekotorye svojstva turbulentnoj plazmy. Magnitnoe pole narastalo do 9 kje za 1,75 msek. Pri poljah ot 0,5 do 9 kje lovushka zapolnjalas' dejterievoj plazmoj plotnost'ju 10{sup 12}-10{sup 13} sm-3 iz titanovyh inzhektorov. Odnovremenno mezhdu ih koncevymi jelektrodami vkljuchalas' emkost' prjamogo razrjada, zarjazhennaja do 10 Division-Sign 30 kv i sostavljajushhaja v razlichnyh opytah 0,2, 0,8 i 2,65 mkf. Razrjad nachinalsja v moment vstrechi plazmennyh struj. Vnachale on aperiodicheskij, s medlennym narastaniem toka, i na oscillogrammah nabljudajutsja kolebanija, svidetel'stvujushhie o neustojchivosti toka. Soprotivlenie plazmy, opredelennoe po toku i naprjazheniju na plazme, znachitel'no bol'she rasschitannogo po vremeni kulonovskih stolknovenij. Vnachale ono ravno 50-60 om i po mere zapolnenija lovushki i nagreva plazmy padaet do desjatyh dolej oma. Shumy na oscillogrammah toka prekrashhajutsja i razrjad stanovitsja kolebatel'nym. Pokazano, chto dlitel'nost' aperiodicheskogo rezhima opredeljaetsja vremenem zapolnenija. Iz izmerenij raspredelenija potenciala sleduet, chto do perehoda razrjada v kolebatel'nyj rezhim osnovnoe padenie potenciala proishodit v seredine lovushki, v oblasti ponizhennoj plotnosti. Zdes' tokovye skorosti maksimal'ny, i dolzhna razvivat'sja intensivnaja turbulentnost'. V rezul'tate voznikaet anomal'noe soprotivlenie plazmy i pogloshhaetsja znachitel'naja

  15. Perspectives for the Use of Ionizing Radiation in the Decontamination (Salmonella Radicidation) of Some Frozen Proteinaceous Foods and Dry Mixed Feed Ingredients; Perspectives de l'Emploi des Rayonnements pour la Decontamination (Radicidation de Salmonella) de Certains Aliments Proteiques Congeles et des Constituants de Melanges Alimentaires Secs pour Animaux; Perspektivy ispol'zovaniya ioniziruyushchego izlucheniya dlya unichtozheniya bakterij (Gruppy Salmonella) nekotorykh zamorozhennykh belkovykh osnovnykh pishchevykh produktov i sukhikh komponentov smeshannogo'fura; Radiodescontaminacion (Radicidacion de la Salmonella) de Algunos Alimentos Proteicos Basicos Congelados y de Componentes de Alimentos Secos para Animales

    Mossel, D. A.A. [Central Institute for Nutrition and Food Research T.N.O., Zeist (Netherlands)

    1966-11-15

    escala comercial. (author) [Russian] Radiacionnaja dezaktivacija, osobenno belkovyh osnovnyh pishhevyh produktov nizkoj vodnoj aktivnosti, kak predstavljalos', dolzhna byla ispol'zovat'sja v kachestve odnogo iz pervyh primenenij ionizirujushhej jenergii v obrabotke pishhevyh produktov i furazha v silu a) ogranichennogo radiohimicheskogo povrezhdenija sootvetstvujushhih predmetov potreblenija; b) otsutstvija mikrobnoj proliferacii posle obluchenija; v) nekotoryh, chasto edinstvennyh v svoem rode, tehnologicheskih preimushhestv, kak, naprimer, primenimosti k uzhe upakovannym materialam, naprimer, k komponentam smeshannogo furazha, i jeffektivnoj dezaktivacii bez odnovremennoj poteri svezhesti, chto imeet mesto v sluchae s obychnym mjasom i mjasom domashnej pticy. V kachestve pervogo shaga byli provedeny laboratornye opyty po opredeleniju diapazona doz v jetoj oblasti odnovremenno s pochti maksimal'nym ispytaniem na sohranenie vkusovyh i pitatel'nyh kachestv. Poskol'ku rezul'taty jetih opytov javljalis' ves'ma obnadezhivajushhimi, byli provedeny opytnye ispytanija, hotja odnovremenno nauchnye issledovanija na sohranenie vkusovyh i pitatel'nyh kachestv byli prodleny na polnye dva goda, i prove- . deny opyty na treh pokolenijah krys. V hode jetih opytov bylo podtverzhdeno, chto doza porjadka 0,7{+-}0,1 megarad ves'ma dostatochna dlja udalenija salmonelly iz zamorozhennyh i zasushennyh belkovyh produktov, kak, naprimer, kurjatiny, rybnoj muki i smeshannogo furazha. Esli po prichinam analiticheskogo haraktera nuzhno bylo otdat' predpochtenie otricatel'nomu jenterobakterial'nomu ispytaniju dlja znachitel'nogo chisla obrazcov porjadka 10 g materiala, podvergnutogo dejstviju ionizirujushhego izluchenija, doza izluchenija dolzhna byla byt' neskol'ko uvelichena; strogaja maksimal'naja doza dolzhna sostavljat' v takom sluchae 1,0 megarad, naprimer, esli nuzhno obrabotat' smeshannyj furazh, pervonachal'no soderzhavshij bol'shoe chislo otnositel'no ustojchivyh k izlucheniju

  16. Applications of Fluorine-18 in Biological Studies with Special Reference to Bone and Thyroid Physiology; Emploi du Fluor-18 dans des Études Biologiques, Notamment sur la Physiologie des Os et de la Thyroïde; ИСПОЛЬЗОВАНИЕ ФТОРА-18 В БИОЛОГИЧЕСКИХ ИССЛЕДОВАНИЯХ С УДЕЛЕНИЕМ ОСОБОГО ВНИМАНИЯ ВОПРОСАМ ФИЗИОЛОГИИ КОСТЕЙ И ФИЗИОЛОГИИ ПИТОВИДНОЙ ЖЕЛЕЗЫ; Aplicaciones del Fluor-18 en Estudios Biologicos, con Especial Referencia a la Fisiologia del Esqueleto y de la Tiroides

    Anbar, M. [Weizmann Institute of Science (Israel); IAEC Soreq Research Establishment, Rehovot (Israel)

    1963-03-15

    4} estimula la accion inhibidora que ejercen sobre la captacion de yodo los iones hierro, cobre, cinc, cadmio, fluoruro, tiocianiato y otros, demostrando que en ella interviene la funcion de captacion. En una serie analoga de experimentos, se encontro que los compuestos sulfhidrilicos y las azidas incrementan la captacion de fluoroborato, aunque disminuyen la captacion total de yodo. Seguidamente, se demostro que la funcion de captacion es menos radiosensible que las funciones de formacion y liberacion de tiroxina. Otra aplicacion muy distinta de los iones fluoroborato marcados con {sup 18}F fue la localizacion de tumores cerebrales por exploracion direccional de coincidencias en la que se aprovecha la baja permeabilidad para estos iones de la barrera sangre- cerebro intacta. Se prepararon agentes de quelacion fluoroaromaticos marcados con {sup 18}F y se aplicaron a problemas de fisiologia de tejido oseo. Para estudiar la permeabilidad a traves de membranas biologicas, se emplearon colorantes aromaticos vitales marcados con {sup 18}F. Se han preparado antimeiabolitos que contienen fluor, marcados con {sup 18}F, entre otros, el 5-fluorouracilo y el acido fluoroorotico y se han aplicado al estudio de problemas fisiologicos e investigaciones sobre el cancer. (author) [Russian] V techenie poslednih treh let ftor-18 primenjaetsja v nashej laboratorii dlja razlichnyh biologicheskih i medicinskih issledovanij. Razrabotany metody poluchenija ftora v rezul'tate reakcij s O{sup 16} (p, n), O{sup 15} (H{sup 3}, p), i F{sup 18} (n, 2 ,). Soedinenija, mechennye radioaktivnym ftorom, byli poducheny metodom izotopnogo obmena sinteza, mechenija otdachej i uderzhivaniem ftora vo ftoroorganicheskih soedinenijah v rezul'tate reakcii (p,2 p). Razrabotana special'naja tehnika scheta nizkogo urovnja aktivnosti dlja raboty s malymi aktivnostjami indikatornyh kolichestv organicheskih ftoristyh soedinenij. Iony ftora-18 byli ispol'zovany pri izuchenii fiziologii kostej. Bylo obnaruzheno

  17. Design and Function of a Brain Scanner for Clinical Use; Etude d'un Appareil de Scintigraphy du Cerveau - Son Role Clinique; Ustrojstvo i funktsiya pribora dlya skennirovaniya mozga i ego klinicheskoe ispol'zovanie; Diseffo y Funcion de un Aparato de Exploracion del Cerebro para Uso Clinico

    Paul, W.; Morley, T. P. [Department of Pathological Chemistry and Department of Surgery, University Of Toronto (Canada)

    1964-10-15

    repite en direccion anteroposterior. Entre septiembre de 1961 y noviembre de 1962 se efectuaron 789 exploraciones en 653 pacientes. Para 109 de ellos el diagnostico se confirmo: 88 tenian tumores. De 30 glioblastomas, se localizaron claramente23; de 19 meningiomas se localizaron 15. (author) [Russian] Tak kak mozg cheloveka obladaet dvustoronnej simmetriej i neobychnoj soprotivljaemost'ju v otnoshenii mnogih veshhestv, soderzhashhihsja v krovi, predpolagaetsja, chto radioaktivnoe skennirovanie jetoj oblasti luchshe vsego osushhestvljat' s pomoshh'ju special'nogo pribora. Daetsja opisanie skennera. prednaznachennogo dlja vyjavlenija bol'nyh s predpolagaemymi opuholjami mozga. Poi jetom osnovnymi trebovanijami k priboru javljalis' vysokaja chuvstvitel'nost', prostota podgotovki pacienta, chtenija i interpretacii dannyh. V uravnenii Braunella o sootnoshenii mezhdu koncentraciej radioaktivnosti i diametrom razreshenija ukazyvaetsja, chto uroven' neobhodimoj radioaktivnosti na edinicu ob{sup e}ma obratno proporcionalen shestoj stepeni diametra razreshenija. Sootvetstvenno maksimal'no dopustimyj diametr razreshenija vybiralsja v zavisimosti ot udovletvoritel'noj lokalizacii oblastej s povyshennoj radioaktivnost'ju. Tochnyh konturov ne trebovalos'.1 Poskol'ku kolichestvo obnaruzhivaemyh raspadov na edinicu vremeni predstavljaet soboj obratnuju funkciju kvadrata rasstojanija, celesoobraznee ispol'zovat' dva detektora s korotkim {sup f}okusom{sup ,} a ne odin detektor, kotoryj dolzhen byt' optimal'nym v sredne-sagit- tal'noj ploskosti. Kristallicheskaja sborka diametrom 5 sm i fotoumnozhitel'naja sborka montirujutsja drug protiv druga v zhestkoj sheme skennirovanija, prichem kazhdaja sborka snabzhaetsja fokusirujushhim kollimatorom s sem'ju otverstijami ( v geksagonal'nom porjadke), prednaznachennym dlja poluchenija diametra razreshenija 1,5 sm i fokusa na rasstojanii 8 sm ot poverhnosti kollimatora. Skennirovanie vedetsja prjamolinejno v sagittal'noj ploskosti. Skennogrammy

  18. Anomalous Escape of Ions into the ''Loss Cone''; Sortie Anormale d'Ions dans Le Cone de Pert; Anomal'nyj ukhod ionov v konus poter'; Escape Anomalo de Iones al Cono de Perdid

    Galeev, A. A. [Institut Jadernoj Fiziki so AN SSSR, Novosibirsk, SSSR (Russian Federation)

    1966-04-15

    , fundamentalmente en las pulsaciones de gran escala, depende esencialmente de la longitud de la instalacion ({Omega}{sub H}{tau}-10{sup 5}R{sub H}/L; R{sub H} = radio de Larmor de los iones termicos). El tiempo de escape de las particulas, desde la trampa, a traves de los espejos magneticos queda determinado por el tiempo maximo ({tau}, T Almost-Equal-To L/v{sub i}; v{sub i} = velocidad termica del ion). Los resultados obtenidos sirven para estimar la posibilidad de lograr una fusion termonuclear regulada en una trampa con espejos magneticos. Para hacer esta estimacion se han utilizado los valores de los parametros optimos de la trampa, obtenidos por Post mediante la comparacion de las perdidas de energia de un plasma en calma, en un sistema de espejos, y de las perdidas en los sistemas auxiliares, con la produccion total de energia en la reaccion termonuclear. Se muestra que la vida del plasma en dicha trampa esta determinada por el tiempo de transito de los iones termicos entre los espejos magneticos y que no es suficiente para el aprovechamiento de la fusion termonuclear en condiciones economicas. (author) [Russian] Neravnovesnost' plazmy, uderzhivaemoj v lovushke s magnitnymi probkami, privodit k vozniknoveniju zhelobkovoj, universal'noj i anizotropnoj neustojchivosti, kotorye sushhestvenno ogranichivajut vremja uderzhanija chastic. Zhelobkovaja neustojchivost', kak sejchas schitajut, mozhet byt' podavlena special'nym vyborom geometrii magnitnogo polja (tak nazyvaemye minimum V - konfiguracii). Universal'naja neustojchivost', objazannaja neodnorodnosti raspredelenija plazmy poperek magnitnogo polja takzhe stabiliziruetsja pri sravnitel'no maloj perekreshhennosti silovyh linij magnitnogo polja. S drugoj storony, Rozenbljut i Post nedavno zametili, chto v plazme dostatochnoj plotnosti ni n Greater-Than-Or-Equivalent-To 10{sup 13} cm{sup -3} i dostatochnoj dliny L Greater-Than-Or-Equivalent-To 10{sup 4{lambda}}{sub D} (gde {lambda}{sub D} - debaevskij radius) uzhe slabaja

  19. Application of Sodium-24 to Flow-Rate Measurements and Leak Detection; Applications du Sodium-24 a des Mesures de Debits et de Recherches de Fuites; ИСПОЛЬЗОВАНИЕ НАТРИЯ-24 ПРИ ИЗМЕРЕНИЯХ ПОТОКОВ И ИССЛЕДОВАНИЯХ УТЕЧКИ; Aplicaciones del Sodio-24 a la Medicion de Caudales y Deteccion de Escapes

    Guizerix, J.; Cornuet, R. [Centre d' Etudes Nucleaires, Grenoble (France)

    1963-03-15

    de transito de la onda de actividad entre dos detectores de centelleo colimados permitio determinar el caudal con una precision relativa del 2%, aproximadamente. (author) [Russian] Avtory opisyvajut nekotorye opyty, v kotoryh v kachestve indikatora ispol'zovalsja natrij-24 s cel'ju iskljuchenija problemy dezaktivacii i povtornogo vvedenija indikatorov. Obluchenie natrija bylo proizvedeno v bassejnovom reaktore 'Meljuzin' v Issledovatel'skom jadernom centre v Grenoble (Frakcija). S cel'ju issledovanija utechki v sisteme central'nogo otoplenija vodjanaja sistema metilas' karbonatom natrija-24. Posle ochishhenija i promyvki sistemy byla sostavlena tshhatel'naja shema issleduemogo uchast-. ka, ogranichivajushhaja zonu issledovanija. S pomoshh'ju kollimirovannyh priborov issledovalas' pochva, tochnye krivye ijeoaktivnosti issledovalis' dlja poluchenija razlichnyh dannyh. Obuslovlennoe utechkoj prevrashhenie v zavisimosti ot vremeni issleduemoj zony radioaktivnosti pozvolilo vydelit' ego na foke issleduemyh zon v rajone nepodvizhnyh trub ili v mestah sil'nogo pogloshhenija indikatora. Issledovalas' utechka na germeticheski zakrytom svincovom bake. Jetot bak pomeshhalsja mezhdu dvumja jarusami, pod nastilom rezervuara s vodoj, i byl prednaznachen dlja sbora vody, kotoraja mogla pojavit'sja v rezul'tate vozmozhnoj utechki v gidravlicheskih ustanovkah, raspolozhennyh v verhnem jaruse. V bak vvodilas' voda, mechennaja izotopom natrija-24. Nalozhenie radioaktivnyh pjaten v nizhnej i verhnej chastjah utechki, a takzhe slabyj vyhod potoka, ocenivaemogo v 1 sm{sup 3}/min, vyzvali izvestnuju trudnost' v issledovanii, i tol'ko chetkoe mestopolozhenie i rost radioaktivnogo pjatna pozvolili pri pomoshhi krivyh ijeoaktivnosti za 15 chasov opredelit' polozhenie utechki. V celjah opredelenija vozmozhnoj utechki porjadka 1 l/chas, kotoraja imeet mesto mezhdu sistemoj vodjanogo ohlazhdenija i sistemoj acetata celljulozy, potoki kotoryh izvestny i sostavljajut primerno 5 m3/chas

  20. Recent Research on the Irradiation of Fruits and Vegetables; Recherches Recentes sur l'Irradiation des Fruits et Legumes; Poslednie issledovaniya po oblucheniyu fruktov i ovoshchej; Investigaciones Recientes Sobre la Irradiacion de Frutas y Verduras

    Sommer, N. F.; Maxie, E. C. [University of California, Davis, CA (United States)

    1966-11-15

    madurar. Las dosis de 20 a 35 krad inhiben la maduracion de los platanos de 4 a 15 dias, segun el grado de sazon y la importancia delas deteriora-, ciones mecanicas sufridas por la fruta. Las frutas irradiadas sometidas a un tratamiento tipo con etileno maduran en buenas condiciones. Los melocotones y persicos sometidos a dosis de rayos gamma capaces de retardar la putrefaccion son muy sensibles a los danos debidos al transporte. La irradiacion de papayas con rayos gamma para eliminar la mosca de la fruta de Hawaii presenta perspectivas alentadores. El periodo de almacenamiento de las frutas irradiadas es de 3 a 5 dias mayor que el de las frutas sometidas a fumigacion con dibromuro de etileno. En ia memoria se examinan las perspectivas que ofrece la irradiacion de varias frutas y verduras. (author) [Russian] Posleuborochnaja radiacionnaja obrabotka fruktov i ovoshhej vyzvala bol'shoj interes s tochki zrenija bor'by s rynochnymi boleznjami, zarazhenija nasekomymi, zamedlenija sozrevanija i zaderzhki rosta. Obluchenie kak sredstvo bor'by protiv gribkov predstavljaet osobyj interes vvidu svoego terapevticheskogo dejstvija. K sozhaleniju, doza obluchenija chasto sil'no ogranichena vvidu chuvstvitel'nosti ''hozjaina'': Te ili inye vidy i sorta imejut razlichnuju stojkost' k oblucheniju, na kotoruju vlijaet stepen' sozrevanija v moment obluchenija. Esli produkty napravljajutsja v hranilishha, to ih mozhno obluchit' nebol'shoj dozoj vvidu zamedlennyh neblagoprijatnyh vozdejstvij. Zaderzhka rosta patogennogo mikroorganizma zavisit glavnym obrazom ot ego chuvstvitel'nosti i razmera porazhennogo, mesta. Obychno znachitel'naja chast' nebol'shih gribkovyh porazhenij inaktiviruetsja, a razvitie drugih porazhenij priostanavlivaetsja. V nastojashhee vremja radiacionnaja obrabotka javljaetsja naibolee perspektivnym metodom v teh sluchajah, kogda problemy bolezni javljajutsja ves'ma ser'eznymi, kak naprimer, pri obrabotke skoroportjashhihsja tovarnyh fruktov i ovoshhej, kotorye

  1. Anomalous Plasma Diffusion in Magnetic Wells; Diffusion Anormale de Plasma dans des Puits Magnetique; Anomal'naya diffuziya plazmy v magnitnykh yamakh; Difusion Anomala de Plasma en Pozos Magneticos

    Fowler, T. K.; Guest, G. E. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1966-04-15

    osvobozhdenija teplovoj jenergii sposobom, analogichnym rasshireniju ohlazhdajushhegosja gaza, o chem govorit anomal'naja diffuzija v celom rjade jeksperimentov, gde dB/dr Less-Than-Or-Equal-To 0. Dlja dostatochno bol'shogo polozhitel'nogo dB/dr, chlen Greek-Small-Letter-Delta W{sub 0} javljaetsja otricatel'nym i preodolevaet jeto. Togda lish' nebol'shoe azimutal'noe smeshhenie jenergii upravljaet rostom polja. Delaetsja sravnenie s linejnoj teoriej, bez ucheta jenergii drejfa. (author)

  2. The Formation of Polymeric Products in Reactions of Polyvalent Recoil Atoms; Formation de Polymeres lors de Reactions Provoquees par des Atomes de Recul Polyvalents; Obrazovanie polimernykh produktov pri reaktsiyakh polivalentnykh atomov otdachi; Formacion de Polimeros en las Reacciones de Atomos de Retroceso Polivalentes

    Dzantiev, B. G.; Stukan, R. A.; Shvedchikov, A. P.; Shishkov, A. V. [Institut Himicheskoj Fiziki AN SSSR, Moskva, SSSR (Russian Federation)

    1965-04-15

    pri obluchenii chistogo bezvodnogo ammiaka osnovnym mechenym produktom javljaetsja C{sup 14}H{sub 4}. Odnako uzhe malye dobavki jetilena privodjat k tomu, chto znachitel'naja dolja (do 80%) C{sup 14} stabiliziruetsja v forme polimera, vyhod kotorogo takzhe menjaetsja jekstremal'no s rostom doli jetilena v sisteme, dostigaja maksimuma pri 10 - 15% C{sub 2}H{sub 4}. Pokazano, chto vid krivoj vyhoda polimera C{sup 14} ne menjaetsja s uvelicheniem moshhnosti dozy i potoka. (author)

  3. Theoretical and Experimental Aspects of Quenching Variables from Biomedical Samples in Liquid Scintillator Systems; Aspects Theoriques et Experimentaux des Parametres d'Extinction Etudies sur des Echantillons Biomedicaux dans des Systemes a Scintillateur Liquide; Teoreticheskie i ehksperimental'nye aspekty peremennykh gasheniya iz biomeditsinskikh prob v zhidkikh stsintillyatsionnykh sistemakh; Estudio Teorico y Experimental de las Variables de Extincion en el Recuento de Sustancias Biological por Centelleo Liquido

    Ross, H. H. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1965-10-15

    popravki na gashenie dajut vozmozhnost' opredeljat' obshhuju velichinu gashenija v dannoj probe, ne predstavljaetsja vozmozhnym opredeljat' absoljutnuju dolju uchastija v gashenii okraski i fluorescencii. Jeti svedenija predstavljajut bol'shoe znachenie dlja konstrukcii novyh i bolee jeffektivnyh scintilljacionnyh sistem, a takzhe dlja kriticheskoj ocenki bolee staryh sistem s cel'ju vnesenija vozmozhnyh uluchshenij. Nedavno avtoru doklada udalos' vyrabotat' dva nezavisimyh metoda dlja opredelenija, otdel'nyh vyzyvajushhih gashenie peremennyh v zhidkih sistemah. Pervyj metod pokazyvaet, chto na osnovanii spektrofotometricheskih dannyh predstavljaetsja vozmozhnym ispol'zovat' obshhuju matematicheskuju model' dlja tochnogo predskazanija stepeni obescvechivanija v ljuboj probe. Jetot podhod analogichen metodu opredelenija obshhego pogloshhenija sveta v mnogokomponentnoj sisteme, i on privodit v konechnom schete k integral'nomu uravneniju tipa: Q = {integral}{sup {lambda}{sub n{sub {lambda}{sub {sub l}}}}} (K)(A)d{lambda}, kotoroe dlja prakticheskih nadobnostej mozhno legko uprostit'. Jetot metod mozhet davat' tochnye svedenija dlja ocenki kombinirovannogo vozdejstvija gashenija okraski i fluorescencii i vmeste s tem sposobstvovat' luchshemu ponimaniju faktorov, vyzyvajushhih obescvechivanie. Odnako pri neobhodimosti analizirovat' povsednevno bol'shoe kolichestvo prob jeksperimental'naja procedura stanovitsja dovol'no trudoemkoj. Vtoroj metod - novyj jeksperimental'nyj metod vnesenija popravki na gashenie okraski putem ispol'zovanija {sup i}zolirovannogo vnutrennego standarta{sup .} Primenjaja jetot metod s ljubymi drugimi metodami opredelenija obshhej popravki na gashenie, mozhno legko otdelit' vozdejstvie gashenija okraski ot himicheskogo gashenija. Metod izolirovannogo vnutrennego standarta osnovan na pogloshhenii svetovyh fotonov v probe zhidkogo scintilljatora s gashenoj okraskoj. Odnako v protivopolozhnost' opisannomu vyshe spektrofotometricheskomu metodu istochnik sveta

  4. Stable and Unstable Behaviour of Preheated Plasma in Linear and Cusped Theta Pinches; Comportement de Plasmas Prechauffes Stables et Instables Soumis a des Strictions Azimutales Lineaires et Cuspidees; Ustojchivoe i neustojchivoe povedenie predvaritel'no nagretoj plazmy v teta-pinch razryadakh s linejnoj i antiprobkovoj geometriej; Comportamiento de Plasmas Precalentados, Estables e Inestables, Sometidos a Constricciones Azimutales de Geometria Lineal y Cuspidal

    Belitz, R. J.; Bogen, P.; Dippel, K. H.; Jordan, H. L.; Kugler, E.; Miyahara, A.; Noll, P.; Schlueter, J.; Witulski, H. [Association EURATOM-Kernforschungsanlage, Juelich (Germany)

    1966-04-15

    10,5 sm f, dlina 128 sm, B{sub max} = 100 kG, T{sub Vulgar-Fraction-One-Half} = 17 {mu}sec. 3. Teta-pinch razrjad v prostranstvennoj antiprobkovoj geometrii pri 10 kdzh s B{sub max} =45 kgs na osi vershinah i v oblasti shheli, radius 5,2 sm, dlina 8,5 sm. Na vseh ustanovkah prisposobleny: predvaritel'naja ionizacija s pomoshh'ju vysokochastotnogo generatora maloj moshhnosti s emkostnoj svjaz'ju, magnitnoe pole smeshhenija s peremennoj naprjazhennost'ju i poljarnost'ju, predvaritel'nyj nagrev s pomoshh'ju impul'snogo.kolebatel'nogo bezjelektrodnogo kol'cevogo razrjada, szhatie plazmy s pomoshh'ju bystrodejstvujushhej kondensatornoj batarei. Dlja nabljudenij ispol'zovalis' fotografirovanie razrjada s nepreryvnoj i kadrovoj razvertkoj vo vremeni, opticheskaja interferometrija s pomoshh'ju interferometra Maha-Cendera i differencial'nogo in- terferometra, spektroskopija v vidimoj oblasti i v oblasti mjagkih rentgenovskih luchej i magnitnye zondy. Jeti metody dajut informaciju o strukture plazmy, o profiljah plotnosti, o raspredelenii jelektronnyh i dopplerovskih ionnyh temperatur i ih izmenenii vo vremeni. V ustanovkah s linejnoj geometriej nabljudalis' kak ustojchivye tak i neustojchivye sostojanija plazmy. Putem izmenenija davlenija, polja smeshhenija, predvaritel'noj ionizacii, predvaritel'nogo nagreva i koncentracii primesej i putem narushenija simmetrii razrjadnoj trubki okazalos' vozmozhnym poluchit' informaciju ob oblastjah s ustojchivymi i neustojchivymi parametrami. Otklonenija ot simmetrii plazmennogo stolba mogut imet' mesto iz-za: 1) smeshhenij, svjazannyh s prostranstvennoj neodnorodnost'ju uderzhivajushhego magnitnogo polja, 2) osevyh dvizhenij i szhatij v plazme s zahvachennym antiparallel'nym polem i voln razrezhenija iz-za poter' na koncah, 3) vrashhenij i deformacionnyh kolebanij poperechnogo sechenija plazmy, 4) zvezdoobraznoj neustojchivosti i izverzhenij. V to vremja kak smeshhenija i osevye dvizhenija neposredstvenno svjazany s konfiguraciej

  5. Plasma Stability in Magnetic Mirror Machine with Stabilizing Rods; Stabilite du Plasma dans une Machine a Miroirs Magnetiques avec Barreaux de Stabilisation; Ustojchivost' plazmy v probkotrone so stabiliziruyushchimi sterzhnyami; Estabilidad del Plasma en una Trampa de Espejos con Barras Estabilizadoras

    Trubnikov, B. A. [Institut Atomnoj Ehnergii Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

    1966-04-15

    indica en la memoria, se puede conseguir la estabilizacion incluso en el caso limite de barras muy cortas, en el cual se las puede considerar como un sistema de 2n dipplos magneticos puntiformes, situados en, el plano central de la trampa de espejos, en una circunferencia de radio a y dirigidos en sentido radial desde el eje (o hacia el eje - las direcciones alternan). Estos sistemas, que hemos considerado a propuesta de Artsimovich, pueden ofrecer muy buenas perspectivas, ya que su estructura simplifica el acceso al plasma y permite instalar un equipo complementario para el diagnostico o el calentamiento del plasma. (author) [Russian] V nastojashhej rabote izvestnyj kriterij Greek-Small-Letter-Delta {integral} Script-Small-L / B < 0 obobshhaetsja na proizvol'nyj sluchaj aksial'no- nesimmetrichnyh polej. Dlja jetogo ego sleduet predstavit' v vide {integral}( Greek-Small-Letter-Delta B/B{sup 2}) (P{sub 0} + P{sub Up-Tack }) d Script-Small-L > 0. Zdes Greek-Small-Letter-Delta B = s x {Delta}B prirashhenie modulja polja na sosednej (vneshnej) silovoj linii, prichem s Up-Tack B. Ukazannyj kriterij primenjaetsja dlja issledovanija ustojchivosti plazmy v probkotrone so stabilizirujushhimi sterzhnjami. Pole vblizi osi opisyvaetsja skaljarnym potencialom: {psi} = {integral} B{sub 0} (z) dz - B{sub 0}{sup 1} (z) r 2/4 + g (z) r{sup n} cos n{phi} prichem dlja polja na samoj osi prinimaetsja parabolicheskaja approksimacija B{sub 0}(z) = B{sub 0}{sup 0} (1 + z{sup 2} /1{sup 2}). Esli 2p sterzhnej s tokom J v kazhdom raspolozheny na okruzhnosti'radiusa a, to ispol'zuja malost' velichiny r{sub 0}/1 << 1 mozhno privesti kriterij ustojchivosti k takomu vidu, chto v nem ostaetsja lish' parametr {alpha} = 4nJ Script-Small-L r{sub 0}{sup n-2}/ca{sup n} B{sup 0}{sub 0} i velichina x = z{sub max}/ Script-Small-L , where z{sub max} -maksimal'naja tochka otrazhenija chastic (z = 0 sootvetstvuet central'noj ploskosti probkotrona). Byli rassmotreny dva raspredelenija chastic: maksvellovskoe s