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Sample records for characterize nitrogen ligation

  1. Characterizing seamless ligation cloning extract for synthetic biological applications.

    Science.gov (United States)

    Messerschmidt, Katrin; Hochrein, Lena; Dehm, Daniel; Schulz, Karina; Mueller-Roeber, Bernd

    2016-09-15

    Synthetic biology aims at designing and engineering organisms. The engineering process typically requires the establishment of suitable DNA constructs generated through fusion of multiple protein coding and regulatory sequences. Conventional cloning techniques, including those involving restriction enzymes and ligases, are often of limited scope, in particular when many DNA fragments must be joined or scar-free fusions are mandatory. Overlap-based-cloning methods have the potential to overcome such limitations. One such method uses seamless ligation cloning extract (SLiCE) prepared from Escherichia coli cells for straightforward and efficient in vitro fusion of DNA fragments. Here, we systematically characterized extracts prepared from the unmodified E. coli strain DH10B for SLiCE-mediated cloning and determined DNA sequence-associated parameters that affect cloning efficiency. Our data revealed the virtual absence of length restrictions for vector backbone (up to 13.5 kbp) and insert (90 bp to 1.6 kbp). Furthermore, differences in GC content in homology regions are easily tolerated and the deletion of unwanted vector sequences concomitant with targeted fragment insertion is straightforward. Thus, SLiCE represents a highly versatile DNA fusion method suitable for cloning projects in virtually all molecular and synthetic biology projects. PMID:27311554

  2. Isolation and characterization of portal branch ligation-stimulated Hmga2-positive bipotent hepatic progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Hiroshi [Department of Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan); Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 B51, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503 (Japan); Tagawa, Yoh-ichi, E-mail: ytagawa@bio.titech.ac.jp [Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503 (Japan); Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 B51, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503 (Japan); PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Tamai, Miho [Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 B51, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503 (Japan); Motoyama, Hiroaki [Department of Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan); Ogawa, Shinichiro [Department of Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan); McEwen Center for Regenerative Medicine, University Health Network, 190 Elizabeth Street, Toronto, Ont., Canada M5G 2C4 (Canada); Soeda, Junpei; Nakata, Takenari; Miyagawa, Shinichi [Department of Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan)

    2010-12-17

    Research highlights: {yields} Hepatic progenitor cells were isolated from the portal branch-ligated liver of mice. {yields} Portal branch ligation-stimulated hepatic progenitor cells (PBLHCs) express Hmga2. {yields} PBLHCs have bidirectional differentiation capability in vitro. -- Abstract: Hepatic stem/progenitor cells are one of several cell sources that show promise for restoration of liver mass and function. Although hepatic progenitor cells (HPCs), including oval cells, are induced by administration of certain hepatotoxins in experimental animals, such a strategy would be inappropriate in a clinical setting. Here, we investigated the possibility of isolating HPCs in a portal branch-ligated liver model without administration of any chemical agents. A non-parenchymal cell fraction was prepared from the portal branch-ligated or non-ligated lobe, and seeded onto plates coated with laminin. Most of the cells died, but a small number were able to proliferate. These proliferating cells were cloned as portal branch ligation-stimulated hepatic cells (PBLHCs) by the limiting dilution method. The PBLHCs expressed cytokeratin19, albumin, and Hmga2. The PBLHCs exhibited metabolic functions such as detoxification of ammonium ions and synthesis of urea on Matrigel-coated plates in the presence of oncostatin M. In Matrigel mixed with type I collagen, the PBLHCs became rearranged into cystic and tubular structures. Immunohistochemical staining demonstrated the presence of Hmga2-positive cells around the interlobular bile ducts in the portal branch-ligated liver lobes. In conclusion, successful isolation of bipotent hepatic progenitor cell clones, PBLHCs, from the portal branch-ligated liver lobes of mice provides the possibility of future clinical application of portal vein ligation to induce hepatic progenitor cells.

  3. Synthesis and Spectroscopic Characterization of Some New Axially Ligated Indium(III Macrocyclic Complexes and Their Biological Activities

    Directory of Open Access Journals (Sweden)

    Gauri D. Bajju

    2014-01-01

    Full Text Available The synthesis and spectroscopic characterization of new axially ligated indium(III porphyrin complexes were reported. Chloroindium(III porphyrin (TPPIn-Cl was obtained in good yield by treating the corresponding free base with indium trichloride. The action of the different phenols on chloroderivatives (TPPIn-Cl led to the corresponding phenolato complexes (TPPIn-X. These derivatives were characterized on the basis of mass spectrometry, 1H-NMR, IR, and UV-visible data. The separation and isolation of these derivatives have been achieved through chromatography. The spectral properties of free base porphyrin and its corresponding metallated and axially ligated indium(III porphyrin compounds were compared with each other. A detailed analysis of UV-Vis, 1H-NMR, and IR suggested the transformation from free base porphyrin to indium(III porphyrin. Besides, 13C-NMR and fluorescence spectra were also reported and interpreted. The stability of these derivatives has also been studied through thermogravimetry. The complexes were also screened for anticancerous activities. Among all the complexes, 4-MePhO-InTPP shows highest anticancerous activity. The title complexe, TPPIn-X (where X = different phenolates, represents a five-coordinate indium(III porphyrin complex in a square-pyramidal geometry with the phenolate anion as the axial ligand.

  4. Characterization of nitrogen compound types in hydrotreated Paraho shale oil

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, S.A.; Latham, D.R.

    1980-10-01

    Results from the separation and characterization of nitrogen compound types in hydrotreated Paraho shale oil samples were obtained. Two samples of Paraho shale oil were hydrotreated by Chevron Research Company such that one sample contained about 0.05 wt. percent nitrogen and the other sample contained about 0.10 wt. percent nitrogen. A separation method concentrate specific nitrogen compound types was developed. Characterization of the nitrogen types was accomplished by infrared spectroscopy, mass spectrometry, potentiometric titration, and elemental analysis. The distribution of nitrogen compound types in both samples and in the Paraho crude shale oil is compared.

  5. Characterization of mRNA-cytoskeleton interactions in situ using FMTRIP and proximity ligation.

    Directory of Open Access Journals (Sweden)

    Jeenah Jung

    Full Text Available Many studies have demonstrated an association between the cytoskeleton and mRNA, as well as the asymmetric distribution of mRNA granules within the cell in response to various signaling events. It is likely that the extensive cytoskeletal network directs mRNA transport and localization, with different cytoskeletal elements having their own specific roles. In order to understand the spatiotemporal changes in the interactions between the mRNA and the cytoskeleton as a response to a stimulus, a technique that can visualize and quantify these changes across a population of cells while capturing cell-to-cell variations is required. Here, we demonstrate a method for imaging and quantifying mRNA-cytoskeleton interactions on a per cell basis with single-interaction sensitivity. Using a proximity ligation assay with flag-tagged multiply-labeled tetravalent RNA imaging probes (FMTRIP, we quantified interactions between mRNAs and β-tubulin, vimentin, or filamentous actin (F-actin for two different mRNAs, poly(A + and β-actin mRNA, in two different cell types, A549 cells and human dermal fibroblasts (HDF. We found that the mRNAs interacted predominantly with F-actin (>50% in HDF, >20% in A549 cells, compared to β-tubulin (<5% and vimentin (11-13%. This likely reflects differences in mRNA management by the two cell types. We then quantified changes in these interactions in response to two perturbations, F-actin depolymerization and arsenite-induced oxidative stress, both of which alter either the cytoskeleton itself and mRNA localization. Both perturbations led to a decrease in poly(A + mRNA interactions with F-actin and an increase in the interactions with microtubules, in a time dependent manner.

  6. Kinetics and equilibria for the axial ligation of bromomethyl (aqua)cobaloxime with pyridines - Isolation characterization and DNA binding

    Indian Academy of Sciences (India)

    Kotha Laxma Reddy; K Ashwini Kumar; N Ravi Kumar Reddy; Penumaka Nagababu; A Panasa Reddy; S Satyanarayana

    2009-11-01

    The kinetics and equilibria for the axial ligation of pyridine and substituted pyridines to bromomethyl(aqua)cobaloxime have been measured spectrophotometrically in aqueous solutions of ionic strength 1.0 M (KC1) at 25°C as a function of H. The binding constants and rate of formation increase in the order 4-NH2Py 4-EtPy > 4-MePy > Py > 2-NH2Py > 2-EtPy. The data have been interpreted based on the basicity of the ligand, -back bonding from Co(III) → L and hard and soft interactions. The rate of substitution of H2O varies with the pKa of the incoming ligand, thus establishing the existence of nucleophilic participation of the ligand in the transition state. We have investigated the DNA binding of bromomethyl(aqua)cobaloxime with DNA. Bromomethyl(ligand)cobaloximes were isolated and characterized by elemental analysis, IR and NMR (1H, 13C) spectra.

  7. Medial plantar nerve ligation as a novel model of neuropathic pain in mice: pharmacological and molecular characterization

    Science.gov (United States)

    Sant’Anna, Morena B.; Kusuda, Ricardo; Bozzo, Tiago A.; Bassi, Gabriel S.; Alves-Filho, José C.; Cunha, Fernando Q.; Ferreira, Sergio H.; Souza, Guilherme R.; Cunha, Thiago M.

    2016-01-01

    Peripheral neuropathic pain is a consequence of an injury/disease of the peripheral nerves. The mechanisms involved in its pathophysiology are not entirely understood. To better understand the mechanisms involved in the development of peripheral nerve injury-induced neuropathic pain, more experimental models are required. Here, we developed a novel peripheral neuropathic pain model in mice by using a minimally invasive surgery and medial plantar nerve ligation (MPNL). After MPNL, mechanical allodynia was established, and mice quickly recovered from the surgery without any significant motor impairment. MPNL causes an increased expression of ATF-3 in the sensory neurons. At 14 days after surgery, gabapentin was capable of reversing the mechanical allodynia, whereas anti-inflammatory drugs and opioids were ineffective. MPNL-induced neuropathic pain was mediated by glial cells activation and the production of TNF-α and IL-6 in the spinal cord. These results indicate MPNL as a reasonable animal model for the study of peripheral neuropathic pain, presenting analgesic pharmacological predictivity to clinically used drugs. The results also showed molecular phenotypic changes similar to other peripheral neuropathic pain models, with the advantage of a lack of motor impairment. These features indicate that MPNL might be more appropriate for the study of neuropathic pain than classical models. PMID:27230787

  8. Characterization of nerve and microvessel damage and recovery in type 1 diabetic mice after permanent femoral artery ligation.

    Science.gov (United States)

    Lozeron, Pierre; Mantsounga, Chris S; Broqueres-You, Dong; Dohan, Anthony; Polivka, Marc; Deroide, Nicolas; Silvestre, Jean-Sébastien; Kubis, Nathalie; Lévy, Bernard I

    2015-09-01

    Neuropathy is the most common complication of the peripheral nervous system during the progression of diabetes. The pathophysiology is unclear but may involve microangiopathy, reduced endoneurial blood flow, and tissue ischemia. We used a mouse model of type 1 diabetes to study parallel alterations of nerves and microvessels following tissue ischemia. We designed an easily reproducible model of ischemic neuropathy induced by irreversible ligation of the femoral artery. We studied the evolution of behavioral function, epineurial and endoneurial vessel impairment, and large nerve myelinated fiber as well as small cutaneous unmyelinated fiber impairment for 1 month following the onset of ischemia. We observed a more severe hindlimb dysfunction and delayed recovery in diabetic animals. This was associated with reduced density of large arteries in the hindlimb and reduced sciatic nerve epineurial blood flow. A reduction in sciatic nerve endoneurial capillary density was also observed, associated with a reduction in small unmyelinated epidermal fiber number and large myelinated sciatic nerve fiber dysfunction. Moreover, vascular recovery was delayed, and nerve dysfunction was still present in diabetic animals at day 28. This easily reproducible model provides clear insight into the evolution over time of the impact of ischemia on nerve and microvessel homeostasis in the setting of diabetes. © 2015 Wiley Periodicals, Inc. PMID:25944265

  9. TiO2 doped with nitrogen: synthesis and characterization.

    Science.gov (United States)

    Abazović, Nadica D; Montone, Amelia; Mirenghi, Luciana; Janković, Ivana A; Comor, Mirjana I

    2008-02-01

    In this study, nitrogen-doped titanium dioxide (TiO2) powders were synthesized in two ways: by heating of titanium hydroxide with urea and by direct hydrolysis of titanium tetraisopropoxide (TTIP) with ammonium hydroxide. The samples were characterized by structural (XRD), analytical (XPS), optical (UV/Vis absorption/reflection and Raman spectroscopy) and morphological (SEM, TEM) techniques. The characterization suggested that the doped materials have anatase crystalline form without any detectable peaks that correspond to dopants. The absorption threshold of titanium dioxide was moved in the visible range of optical spectrum from 3.2 eV to 2.20 eV. Particle sizes of synthesized powders were obtained from XRD measurements and from TEM data ranging from 6-20 nm. XPS and Raman spectroscopy were used for detection of nitrogen in doped samples. PMID:18464379

  10. Synthesis and Preliminary Characterization of a PPE-Type Polymer Containing Substituted Fullerenes and Transition Metal Ligation Sites

    Directory of Open Access Journals (Sweden)

    Corinne A. Basinger

    2015-01-01

    Full Text Available A substituted fullerene was incorporated into a PPE-conjugated polymer repeat unit. This subunit was then polymerized via Sonogashira coupling with other repeat units to create polymeric systems approaching 50 repeat units (based on GPC characterization. Bipyridine ligands were incorporated into some of these repeat units to provide sites for transition metal coordination. Photophysical characterization of the absorption and emission properties of these systems shows excited states located on both the fullerene and aromatic backbone of the polymers that exist in a thermally controlled equilibrium. Future work will explore other substituted polyaromatic systems using similar methodologies.

  11. Improvements to the Characterization of Organic Nitrogen Chemistry

    Science.gov (United States)

    Excess atmospheric nitrogen deposition can cause significant harmful effects to ecosystems. Organic nitrogen deposition can be an important contributor to the total nitrogen budget, contributing 10-30%, however there are large uncertainties in the chemistry and deposition of thes...

  12. Characterization of Nitrogen use efficiency in sweet sorghum

    Energy Technology Data Exchange (ETDEWEB)

    Dweikat, Ismail [University of Nebraska; Clemente, Thomas [University of Nebrask

    2014-09-09

    Sweet sorghum (Sorghum bicolor L. Moench) has the potential to augment the increasing demand for alternative fuels and for the production of input efficient, environmentally friendly bioenergy crops. Nitrogen (N) and water availability are considered two of the major limiting factors in crop growth. Nitrogen fertilization accounts for about 40% of the total production cost in sorghum. In cereals, including sorghum, the nitrogen use efficiency (NUE) from fertilizer is approximately 33% of the amount applied. There is therefore extensive concern in relation to the N that is not used by the plant, which is lost by leaching of nitrate, denitrification from the soil, and loss of ammonia to the atmosphere, all of which can have deleterious environmental effects. To improve the potential of sweet sorghum as a leading and cost effective bioenergy crop, the enhancement of NUE must be addressed. To this end, we have identified a sorghum line (SanChi San) that displays about 25% increase in NUE over other sorghum lines. As such, the overarching goal of this project is to employ three complementary strategies to enhance the ability of sweet sorghum to become an efficient nitrogen user. To achieve the project goal, we will pursue the following specific objectives: Objective 1: Phenotypic characterization of SanChi San/Ck60 RILs under low and moderate N-availability including biochemical profiles, vegetative growth and seed yield Objective 2: Conduct quantitative trait loci (QTL) analysis and marker identification for nitrogen use efficiency (NUE) in a grain sorghum RIL population. Objective 3: Identify novel candidate genes for NUE using proteomic and gene expression profiling comparisons of high- and low-NUE RILs. Candidate genes will be brought into the pipeline for transgenic manipulation of NUE This project will apply the latest genomics resources to discover genes controlling NUE, one of the most complex and economically important traits in cereal crops. As a result of the

  13. Metal complexes of the nanosized ligand N-benzoyl-N‧-(p-amino phenyl) thiourea: Synthesis, characterization, antimicrobial activity and the metal uptake capacity of its ligating resin

    Science.gov (United States)

    Elhusseiny, Amel F.; Eldissouky, Ali; Al-Hamza, Ahmed M.; Hassan, Hammed H. A. M.

    2015-11-01

    The new nanosized N-benzoyl-N‧-(p-amino phenyl) thiourea ligand H2L was synthesized by nanoprecipitation method. The [Cu (H2L)2 Cl]·2H2O, [Zn (H2L)2(OAc)2], [Cd (H2L)2Cl2] and [Hg (H2L)2Cl2] complexes were synthesized and characterized by various physicochemical methods. Results revealed that the ligand act as hypodentate and bonded to the metal ion via the sulfur atom forming mononuclear non-electrolyte diamagnetic complex. Magnetic moment results indicated a reduction of Cu (II) to Cu (I) during the coordination process. Thermal studies demonstrated variable stabilities of the complexes and [Zn (H2L)2(OAc)2] exhibited the highest thermal stability while [Hg (H2L)2Cl2] was volatile. The prepared compounds were screened against different pathogenic microorganisms. The ligand performed high antibacterial activity against certain bacterial strain compared to its complexes, and the standard bacteriocide in use. The ligand was successfully immobilized on modified Amberlite XAD-16 forming the hypodentate ligating resin PS-SO2-H2L. The new resin was characterized and the extent of metal adsorption reached maximum at pH 6.0 for Cu (II), Cd (II) and Ag (I), with an adsorption amount of 4.3, 4.0 and 3.7 mmol g-1 respectively. The nanosized H2L represents a new category of promising adsorbent that would have a practical impact on biological and water treatment applications.

  14. Influence of Oxygen Partial Pressure of Femoral Head After Nour-ishing Blood Ligation and Liquid Nitrogen Frozen%营养动脉结扎和液氮冷冻对股骨头内局部氧分压的影响

    Institute of Scientific and Technical Information of China (English)

    李章华; 廖文; 吴丽平; 李超群; 唐欢; 潘峰; 郭义

    2013-01-01

    Objective: To observe the influence of nutrient artery ligation and liquid nitrogen frozen on partial pressure of oxygen in the femoral head, and to explore the possibility of making avascular necrosis of femoral head (ANFH) model via extremely hypoxia. Methods:9 male white rabbits were randomly divided into control group, liquid nitrogen frozen group, nutrient artery ligation and liquid nitrogen frozen group on average. Control group re-ceived no treatment, liquid nitrogen frozen group was established the models of ANFH by liquid nitrogen frozen method, nutrient artery ligation and liquid nitrogen frozen group was established the models of ANFH by ligating nutrient artery of femoral head before liquid nitrogen frozen. The self-made complex transducer of partial oxygen pressure and intelligent four-channel partial oxygen pressure detector were adopted to monitor the change of par-tial oxygen pressure in femoral head. Results:The partial pressure of oxygen in the femoral head of the liquid ni-trogen frozen group declined by half compared with control group, there are significant differences between two groups(P<0.05). The partial pressure of oxygen in the femoral head of the nutrient artery ligation and liquid nitro-gen frozen group further declined to one-eighth of control group, there are significant differences compared with other groups(P<0.05). Conclusion:Nutrient artery ligation and liquid nitrogen frozen could significantly reduced partial pressure of oxygen in the femoral head, and combination of two methods would further decline the partial pressure of oxygen in the femoral head.%目的:观察营养动脉结扎和液氮冷冻对股骨头内局部氧分压的影响,为后期制作极度低氧股骨头缺血坏死模型打下基础。方法:9只雄性大耳白兔随机平均分为对照组、液氮冷冻组和动脉结扎+液氮冷冻组,对照组动物不做任何处理,液氮冷冻组动物行股骨头液氮冷冻使其发生缺血坏死,动脉

  15. Rapid identification and characterization of Penicillium marneffei using multiplex ligation-dependent probe amplification (MLPA) in paraffin-embedded tissue samples

    NARCIS (Netherlands)

    J.M. Zhang; J.F. Sun; P.Y. Feng; X.Q. Li; C.M. Lu; S. Lu; W.Y. Cai; L.Y. Xi; G.S. de Hoog

    2011-01-01

    Penicillium marneffei infection is a deadly disease and early diagnosis leads to prompt and appropriate antifungal therapy. To develop a sensitive method to diagnose P. marneffei infection, a multiplex ligation-dependent probe amplification (MLPA) assay was adapted. This method can rapidly and speci

  16. Stereochemistry of new nitrogen containing heterocyclic aldehyde. Part XI. Novel ligational behaviour of quinoline as chelate ligand toward transition metal ions

    Science.gov (United States)

    El-Sonbati, A. Z.; Al-Shihri, A. S.; El-Bindary, A. A.

    2004-07-01

    Novel complexes of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II) and UO 2(II) with a new Schiff base derived from 8-hydroxy-7-quinolinecarboxaldehyde and 2-aminoethanethiol (LH 2) (system name: 2-(8-hydroxy-7-carboxalimino)ethanethiol.) have been prepared and characterized on the basis of analytical, thermal, magnetic moment, infrared, electronic, NMR and EPR spectral data. From the analytical, NMR and thermal data and stoichiometry of the complexes indicate that LH 2 act as a dibasic tridentate ligand with ONS donors towards all the metal ions. The magnetic moment, electronic and EPR spectral data commensurate that the Mn(II), Fe(II), Ni(II) and UO 2(II) complexes are dimeric with octahedral configuration while the Cu(II) and Zn(II) complexes are monomeric with square-planar and tetrahedral geometries, respectively. Various ligand field parameters Dq, B and β for complex 5 was calculated. The complexes 3+ 4 have lower symmetries and the amount of distortion in terms of DT/DQ applying NSH "Hamiltonian Theory" has been evaluated which indicate that the complexes are moderately distorted.

  17. Self ligating lingual appliance.

    Science.gov (United States)

    Juneja, Pankaj; Chopra, S S; Jayan, B K

    2015-12-01

    Adult demand for orthodontics has grown considerably over the past 10 years propelling increased demand for Esthetic Orthodontics. Lingual appliances are a viable option toward providing Esthetic Orthodontics. The lingual surface of the teeth has a unique morphology that makes it difficult to place brackets in ideal positions. Indirect bonding has become the established methods of overcoming these discrepancies, along with the latest designs of self ligating brackets which offer more efficient mechanics and shorter treatment time. PMID:26843757

  18. Physical and chemical characterization of surfaces of nitrogen implanted steels

    International Nuclear Information System (INIS)

    The studied steels are of industrial type (42CD4, 100C6, Z200C13). Very often, the low carbon steel XCO6 has been used as a reference material. The aim of the research is to understand and to explain the mechanisms of wear resistance to improvement. A good characterization of the implanted layer is thus necessary. It implies to establish the distribution profiles of the implanted ions to identify the chemical and structural state of the phases created during implantation as a function of various implantation parameters (dose, temperature). Temperature is the particularly parameter. Its influence is put in evidence both during implantation and during annealings under vacuum. Nitrogen distribution profiles are performed thanks to the non destructive 15N(p,αγ)12C nuclear reaction. The chemical state of the Fe-N phases formed by implantation is determined using first Electron Conversion Moessbauer Spectroscopy and secondly, as a complement, using grazing angle X ray diffraction. The detected compounds are ε-nitrides, ε-carbonitrides, (N) - martensite and α-Fe16N2 whose evolution is carefully followed versus temperature. The diffraction technique reveals a texture of the implanted layer. This preferentiel orientation is found to be temperature dependent but dose independent. The carbon presence at the surface is studied as a function of implantation conditions (vacuum, temperature, dose). Carbon profiling is obtained using α backscattering (12C(α,α') reaction at 5,7 MeV). Thus is achieved a complete characterization of the implanted zone whose evolution as a function of implantation parameters (especially temperature) is correlated with tribological results

  19. Characterization of nitrogen species incorporated into graphite using low energy nitrogen ion sputtering.

    Science.gov (United States)

    Kiuchi, Hisao; Kondo, Takahiro; Sakurai, Masataka; Guo, Donghui; Nakamura, Junji; Niwa, Hideharu; Miyawaki, Jun; Kawai, Maki; Oshima, Masaharu; Harada, Yoshihisa

    2016-01-01

    The electronic structures of nitrogen species incorporated into highly oriented pyrolytic graphite (HOPG), prepared by low energy (200 eV) nitrogen ion sputtering and subsequent annealing at 1000 K, were investigated by X-ray photoelectron spectroscopy (XPS), angle-dependent X-ray absorption spectroscopy (XAS), and Raman spectroscopy. An additional peak was observed at higher binding energy of 401.9 eV than 400.9 eV for graphitic1 N (graphitic N in the basal plane) in N 1s XPS, where graphitic2 N (graphitic N in the zigzag edge and/or vacancy sites) has been theoretically expected to appear. N 1s XPS showed that graphitic1 N and graphitic2 N were preferably incorporated under low nitrogen content doping conditions (8 × 10(13) ions cm(-2)), while pyridinic N and graphitic1 N were dominantly observed under high nitrogen content doping conditions. In addition, angle-dependent N 1s XAS showed that the graphitic N and pyridinic N atoms were incorporated into the basal plane of HOPG and thus were highly oriented. Furthermore, Raman spectroscopy revealed that low energy sputtering resulted in almost no fraction of the disturbed graphite surface layers under the lowest nitrogen doping condition. The suitable nitrogen doping condition was discovered for realizing the well-controlled nitrogen doped HOPG. The electrochemical properties for the oxygen reduction reaction of these samples in acidic solution were examined and discussed.

  20. Nitrogen-Doped Graphitic Nanoribbons: Synthesis, Characterization and Transport

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Xiaoting [Massachusetts Institute of Technology (MIT); Dresselhaus, M [Massachusetts Institute of Technology (MIT); Cruz Silva, Eduardo [ORNL; Munoz-Sandoval, E [Instituto de Microelectronica de Madrid (CNM, CSIC); Sumpter, Bobby G [ORNL; Terrones Maldonado, Humberto [ORNL; Terrones Maldonado, Humberto [ORNL; Lopez, Florentino [IPICyT

    2013-01-01

    Nitrogen-doped graphitic nanoribbons (Nx-GNRs), synthesized by chemical vapor deposition (CVD) using pyrazine as a nitrogen precursor, are reported for the first time. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) reveal that the synthesized materials are formed by multi-layered corrugated graphitic nanoribbons (GNRs) which in most cases exhibit the formation of curved graphene edges (loops). This suggests that during growth, nitrogen atoms promote loop formation; undoped GNRs do not form loops at their edges. Transport measurements on individual pure carbon GNRs exhibit a linear I-V (current-voltage) behavior, whereas Nx-GNRs show reduced current responses following a semiconducting-like behavior, which becomes more prominent for high nitrogen concentrations. To better understand the experimental findings, electron density of states (DOS), quantum conductance for nitrogen doped zigzag and armchair single-layer GNRs are calculated for different N doping concentrations using Density Functional Theory (DFT) and non-equilibrium Green functions. These calculations confirm the crucial role of nitrogen atoms in the transport properties, confirming that the nonlinear I-V curves are due to the presence of nitrogen atoms within the Nx-GNRs lattice that act as scattering sites. These characteristic Nx-GNRs transport could be advantageous in the fabrication of electronic devices including sensors in which metal-like undoped GNRs are unsuitable.

  1. Evaluation of cerebral electrical activity and cardiac output after patent ductus arteriosus ligation in preterm infants.

    LENUS (Irish Health Repository)

    Leslie, A T F S

    2013-11-01

    To characterize and investigate the relationship between systemic blood flow and pre- and postoperative cerebral electrical activity in preterm neonates undergoing patent ductus arteriosus (PDA) ligation.

  2. Nitrogen

    Science.gov (United States)

    Kramer, D.A.

    2006-01-01

    In 2005, ammonia was produced by 15 companies at 26 plants in 16 states in the United States. Of the total ammonia production capacity, 55% was centered in Louisiana, Oklahoma and Texas because of their large reserves of natural gas. US producers operated at 66% of their rated capacity. In descending order, Koch Nitrogen, Terra Industries, CF Industries, Agrium and PCS Nitrogen accounted for 81% of the US ammonia production capacity.

  3. Nitrogen doped carbon nanotubes : synthesis, characterization and catalysis

    NARCIS (Netherlands)

    van Dommele, S.

    2008-01-01

    Nitrogen containing Carbon Nanotubes (NCNT) have altered physical- and chemical properties with respect to polarity, conductivity and reactivity as compared to conventional carbon nanotubes (CNT) and have potential for use in electronic applications or catalysis. In this thesis the incorporation of

  4. Characterization of Nitrogen Dynamics in Different Recirculation Systems

    OpenAIRE

    Sefranek Rongved, Anna Katharina

    2016-01-01

    The need to reduce freshwater consumption in global food production has long been recognized. Food production in single- and multi-species recirculation systems offers advantages in terms of reduced water and energy consumption, in addition to improved opportunities for waste management and nutrient recycling. In aquaculture, land-based recirculation systems treat the water for waste products, and some is released as wastewater. The wastewater contains a great amount of nitrogen (N), and repr...

  5. Characterization of narrow micropores in almond shell biochars by nitrogen, carbon dioxide, and hydrogen adsorption

    Science.gov (United States)

    Characterization of biochars usually includes surface area and pore volume determination by nitrogen adsorption. In this study, we show that there is a substantial pore volume in biochars created via slow pyrolysis from low- and high-ash almond shells that cannot be characterized in this fashion due...

  6. Preparation and characterization of nitrogen-doped titanium dioxides

    Institute of Scientific and Technical Information of China (English)

    ZHU GuoPing; ZHOU KangGen

    2007-01-01

    A type of high visible-light active titanium oxinitride (TiO2_xNx) powder was prepared by a simple process: the calcination of the hydrated titanium dioxide at the atmosphere of ammonia-argon using a tubular electric furnace at high temperatures. The hydrated titanium dioxide was synthesized as the precursor of TiO2_xNx using titanic acid as raw material, which came from sulfate technique of producing titanium white. The effects of temperature and reaction time on the nitrogen content, grain size and crystal structure were studied. The visible-light activity and photocatalysis capability of the powder were also investigated.

  7. Preparation and characterization of nitrogen-doped titanium dioxides

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A type of high visible-light active titanium oxinitride(TiO2-xNx) powder was prepared by a simple proc-ess:the calcination of the hydrated titanium dioxide at the atmosphere of ammonia-argon using a tu-bular electric furnace at high temperatures. The hydrated titanium dioxide was synthesized as the precursor of TiO2-xNx using titanic acid as raw material,which came from sulfate technique of produc-ing titanium white. The effects of temperature and reaction time on the nitrogen content,grain size and crystal structure were studied. The visible-light activity and photocatalysis capability of the powder were also investigated.

  8. Characterization of La/Fe/TiO₂ and Its Photocatalytic Performance in Ammonia Nitrogen Wastewater.

    Science.gov (United States)

    Luo, Xianping; Chen, Chunfei; Yang, Jing; Wang, Junyu; Yan, Qun; Shi, Huquan; Wang, Chunying

    2015-11-01

    La/Fe/TiO₂ composite photocatalysts were synthesized by Sol-Gel method and well characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen-physical adsorption, and UV-Vis diffuse reflectance spectra (UV-Vis DRS). It is interesting that the doped catalysts were in anatase phase while the pure TiO₂ was in rutile phase. In addition, the composites possessed better physical chemical properties in photocatalytic activity than pure TiO₂: stronger visible-light-response ability, larger specific surface area, and more regular shape in morphology. The photodegradation results of ammonia nitrogen indicate that: the La/Fe/TiO₂ had higher catalytic activity to ammonia nitrogen waste water compared pure TiO₂ and the other single metal-doped TiO₂. pH 10 and 2 mmol/L H₂O₂ were all beneficial to the removal of ammonia nitrogen by La/Fe/TiO₂. However, the common inorganic ions of Cl(-), NO₃(-), SO₄(2-), HCO₃(-)/CO₃²(-), Na⁺, K⁺, Ca(2+) and Mg(2+) in water all inhibited the degradation of ammonia nitrogen. By balance calculation, at least 20% of ammonia nitrogen was converted to N₂ during the 64.6% removal efficiency of ammonia nitrogen.

  9. Characterization of La/Fe/TiO2 and Its Photocatalytic Performance in Ammonia Nitrogen Wastewater

    Science.gov (United States)

    Luo, Xianping; Chen, Chunfei; Yang, Jing; Wang, Junyu; Yan, Qun; Shi, Huquan; Wang, Chunying

    2015-01-01

    La/Fe/TiO2 composite photocatalysts were synthesized by Sol-Gel method and well characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen-physical adsorption, and UV-Vis diffuse reflectance spectra (UV-Vis DRS). It is interesting that the doped catalysts were in anatase phase while the pure TiO2 was in rutile phase. In addition, the composites possessed better physical chemical properties in photocatalytic activity than pure TiO2: stronger visible-light-response ability, larger specific surface area, and more regular shape in morphology. The photodegradation results of ammonia nitrogen indicate that: the La/Fe/TiO2 had higher catalytic activity to ammonia nitrogen waste water compared pure TiO2 and the other single metal-doped TiO2. pH 10 and 2 mmol/L H2O2 were all beneficial to the removal of ammonia nitrogen by La/Fe/TiO2. However, the common inorganic ions of Cl−, NO3−, SO42−, HCO3−/CO32−, Na+, K+, Ca2+ and Mg2+ in water all inhibited the degradation of ammonia nitrogen. By balance calculation, at least 20% of ammonia nitrogen was converted to N2 during the 64.6% removal efficiency of ammonia nitrogen. PMID:26593929

  10. Photoluminescence and Raman spectroscopy characterization of boron- and nitrogen-doped 6H silicon carbide

    DEFF Research Database (Denmark)

    Ou, Yiyu; Jokubavicius, Valdas; Liu, Chuan;

    2011-01-01

    Boron - and nitrogen-doped 6H silicon carbide epilayers grown on low off-axis 6H silicon carbide substrates have been characterized by photoluminescence and Raman spectroscopy. Combined with secondary ion mass spectrometry results, preferable doping type and optimized concentration could...

  11. Characterization of brazilian wheat cultivars in terms of nitrogen use efficiency

    Directory of Open Access Journals (Sweden)

    Cristiano Lemes da Silva

    2014-06-01

    Full Text Available Nitrogen (N management in wheat crop is one of the most studied agricultural practices in Brazil; however, there are few reports on its use efficiency. The objective of this study was to characterize 18 Brazilian wheat cultivars, which are representative and have been recently released to cultivation, for nitrogen use efficiency (NUE. The experiments were carried out in Pato Branco, Paraná, and Coxilha, Rio Grande do Sul, during the 2011 crop season. It was used a randomized block design with three replications, in factorial scheme (2 environments × 18 cultivars. Genetic variability was observed for nitrogen utilization efficiency by grains (NUtEg=47.6 to 81.1 kg kg-1 and nitrogen harvest index (NHI=71.3 to 84.6% with significant effects relating to the environment of cultivation and performance of these traits. The evaluation of the protein concentration of grain by near infrared spectrometry (GPC N produced equivalent results to the direct analytical method of Kjeldahl (GPC K, in Pato Branco (r=0.56 and Coxilha (RS (r=0.80. However the CPG N overestimated the protein values by 16.85%. The GPC and protein yield were positively correlated with NUtEg and NHI. The best performance for the traits associated with NUE was observed for the following cultivars: Mirante, Quartzo, Fundacep Cristalino, Fundacep Raízes and CD 150. This is the first report of differences between Brazilian wheat cultivars for nitrogen use efficiency.

  12. Ligation-assisted endoscopic mucosal resection of gastric heterotopic pancreas

    Institute of Scientific and Technical Information of China (English)

    Mouen A Khashab; Oscar W Cummings; John M DeWitt

    2009-01-01

    Heterotopic pancreas is a congenital anomaly characterized by ectopic pancreatic tissue.Treatment of heterotopic pancreas may include expectant observation,endoscopic resection or surgery.The aim of this report was to describe the technique of ligation-assisted endoscopic mucosal resection (EMR) for resection of heterotopic pancreas of the stomach.Two patients (both female,mean age 32 years) were referred for management of gastric subepithelial tumors.Endoscopic ultrasound in both disclosed small hypoechoic masses in the mucosa and submucosa.Band ligation-assisted EMR was performed in both cases without complications.Pathology from the resected tumors revealed heterotopic pancreas arising from the submucosa.Margins were free of pancreatic tissue.Ligation-assisted EMR is technically feasible and may be considered for the endoscopic management of heterotopic pancreas.

  13. Staudinger ligation as a method for bioconjugation.

    Science.gov (United States)

    van Berkel, Sander S; van Eldijk, Mark B; van Hest, Jan C M

    2011-09-12

    In 1919 the German chemist Hermann Staudinger was the first to describe the reaction between an azide and a phosphine. It was not until recently, however, that Bertozzi and co-workers recognized the potential of this reaction as a method for bioconjugation and transformed it into the so-called Staudinger ligation. The bio-orthogonal character of both the azide and the phosphine functions has resulted in the Staudinger ligation finding numerous applications in various complex biological systems. For example, the Staudinger ligation has been utilized to label glycans, lipids, DNA, and proteins. Moreover, the Staudinger ligation has been used as a synthetic method to construct glycopeptides, microarrays, and functional biopolymers. In the emerging field of bio-orthogonal ligation strategies, the Staudinger ligation has set a high standard to which most of the new techniques are often compared. This Review summarizes recent developments and new applications of the Staudinger ligation. PMID:21887733

  14. Synthesis and Characterization of Phosphine and Arsine Complexes of Ruthenium (Ii & Iii Ligated With 3-(4-Pyridyl-4-Substituted-Triazoline-5-Thione

    Directory of Open Access Journals (Sweden)

    R. N. Pandey

    2014-12-01

    Full Text Available Organometallic complexes of ruthenium (II & III with the formula [RuH(CO(Ef32L] and [RuCl2(Ef32L] (E = P/As; L = deprotonated mononegative bidentate 3-(4-pyridyl-triazoline-5-thione and its 4-phenyl substituted derivative were synthesized and characterized by elemental analysis, physico-chemical and spectroscopic methods. All new compounds were iso-structural with precursor complexes. Two triphenyl phosphine or triphenylarsine molecules are at trans-disposition and thioamide ligands behaves as bidentate (N, S donor in assigned octahedral structure.

  15. Synthesis and characterization of ligational behavior of curcumin drug towards some transition metal ions: Chelation effect on their thermal stability and biological activity

    Science.gov (United States)

    Refat, Moamen S.

    2013-03-01

    Complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with curcumin ligand as antitumor activity were synthesized and characterized by elemental analysis, conductometry, magnetic susceptibility, UV-Vis, IR, Raman, ESR, 1H-NMR spectroscopy, X-ray diffraction analysis of powdered samples and thermal analysis, and screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as a monobasic bidentate ligand towards the central metal ion with an oxygen's donor atoms sequence of both sbnd OH and Cdbnd O groups under keto-enol structure. From the microanalytical data, the stoichiometry of the complexes 1:2 (metal:ligand) was found. The ligand and their metal complexes were screened for antibacterial activity against Escherichia Coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa and fungicidal activity against Aspergillus flavus and Candida albicans.

  16. Zinc acetylacetonate hydrate adducted with nitrogen donor ligands: Synthesis, spectroscopic characterization, and thermal analysis

    Science.gov (United States)

    Brahma, Sanjaya; Shivashankar, S. A.

    2015-12-01

    We report synthesis, spectroscopic characterization, and thermal analysis of zinc acetylacetonate complex adducted by nitrogen donor ligands, such as pyridine, bipyridine, and phenanthroline. The pyridine adducted complex crystallizes to monoclinic crystal structure, whereas other two adducted complexes have orthorhombic structure. Addition of nitrogen donor ligands enhances the thermal property of these complexes as that with parent metal-organic complex. Zinc acetylacetonate adducted with pyridine shows much higher volatility (106 °C), decomposition temperature (202 °C) as that with zinc acetylacetonate (136 °C, 220 °C), and other adducted complexes. All the adducted complexes are thermally stable, highly volatile and are considered to be suitable precursors for metal organic chemical vapor deposition. The formation of these complexes is confirmed by powder X-ray diffraction, Fourier transform infrared spectroscopy, mass spectroscopy, and elemental analysis. The complexes are widely used as starting precursor materials for the synthesis of ZnO nanostructures by microwave irradiation assisted coating process.

  17. Space-resolved characterization of high frequency atmospheric-pressure plasma in nitrogen applying optical emission spectroscopy and numerical simulation

    CERN Document Server

    Rajasekaran, Priyadarshini; Bibinov, Nikita; Awakowicz, Peter

    2011-01-01

    Averaged plasma parameters such as electron distribution function and electron density are determined by characterization of high frequency (2.4 GHz) nitrogen-plasma using both experimental methods, namely optical emission spectroscopy (OES) and microphotography, and numerical simulation. Both direct and stepwise electron-impact excitation of nitrogen emissions are considered. The determination of space-resolved electron distribution function, electron density, rate constant for electron-impact dissociation of nitrogen molecule and the production of nitrogen atoms, applying the same methods, is discussed. Spatial distribution of intensities of neutral nitrogen molecule and nitrogen molecular ion from the microplasma is imaged by a CCD camera. The CCD images are calibrated using the corresponding emissions measured by absolutely-calibrated OES, and are then subjected to inverse Abel transformation to determine space-resolved intensities and other parameters. The space-resolved parameters are compared, respecti...

  18. Spectrum of menstrual problems after tubal ligation

    International Nuclear Information System (INIS)

    To determine the frequency of menstrual problems after tubal ligation. Study Design: Descriptive study. Place and Duration of Study: This study was carried out in gynae department of PAF Hospital Sargodha, Pakistan from September 2011 to September 2012. Patients and methods: Two hundred patients were included in the study with menstrual problems after tubal ligation. Results: Forty seven percent of patients presented with menorrhagia, 28% presented with metrorrhagia, 13% patients were having complaints of polymenorrhoea and 5% patients presented with dysmenorrhea and 7% had oligomenorrhoea after tubal ligation. Thirty one percent of patients ended up in hysterectomy and 37% of patients had improvement of symptoms with medical treatment. Conclusion: Menstrual problem is a common complaint in our gyn ecological patients. A large number of these patients had history of tubal ligation. Menorrhagia, metrorrhagia, polymenorrhoea and dysmenorrhoea can occur after tubal ligation. Patients giving the history of menstrual problems and wants tubal ligation should be counselled earlier for these symptoms. (author)

  19. Improvements to the characterization of organic nitrogen chemistry and deposition in CMAQ (CMAS Presentation)

    Science.gov (United States)

    Excess atmospheric nitrogen deposition can cause significant harmful effects to ecosystems. Organic nitrogen deposition can be an important contributor to the total nitrogen budget, contributing 10-30%, however there are large uncertainties in the chemistry and deposition of thes...

  20. Improvements to the characterization of organic nitrogen chemistry and deposition in CMAQ

    Science.gov (United States)

    Excess atmospheric nitrogen deposition can cause significant harmful effects to ecosystems. Organic nitrogen deposition can be an important contributor to the total nitrogen budget, contributing 10-30%, however there are large uncertainties in the chemistry and deposition of thes...

  1. Mathematical techniques to characterize nitrogen isotherms from eroded sediments under conventional tillage and no tillage

    Science.gov (United States)

    Marinho, M. D.; Paz-Ferreiro, J.

    2011-12-01

    Soil specific surface area (SSA) is one of the most important soil properties as it affects chemical reactivity, cation exchange capacity and, in general, nutrient holding capacity. The SSA of a soil mainly depends on texture, clay type and organic matter content, which in turn are factors affecting the erosion potential. An important consideration in the link between soil erosion and nutrient transfer to waters is the well-documented relation between SSA (or particle size distribution) and nutrient losses. Because, sediment erosion and transport processes are particle size dependent, they influence also SSA. Characterization of both, soil nitrogen adsorption and desorption isotherms by monofractal and multifractal analysis has been demonstrated to be an useful tool, which allows a better understanding of the organization of the soil colloidal complex. Here, we report measures of nitrogen isotherm in sediments produced under three different management histories and we characterize them by various mathematical techniques including fractal and multifractal analysis. Soil and water losses from an Oxisol were evaluated under natural rain, at the experimental station of UNICAMP/ FEAGRI, Campinas, SP, Brazil. Experimental plots were 20 m x 30 m (i.e. 600 m2) and the management systems compared were no-tillage and two different conventional tillage techniques. Specific surface area determined by the classical BET method was significantly lower in sediments eroded from the no-tilled than from the tilled plots. The scaling properties of both nitrogen adsorption and desorption isotherms from all the studied sediment samples could be fitted reasonably well with multifractal models. Various fractal and multifractal parameters obtained from the adsorption and desorption characteristics also were useful to differentiate the impact of tillage treatment on the adsorption and desorption characteristics of the eroded sediments. Reasons for such differences have been already explored.

  2. The "Floss-Ligature" Ligation Technique.

    Science.gov (United States)

    Dugdale, Charlotte Anne; Malik, Ovais Humair; Waring, David Trevor

    2015-01-01

    This clinical pearl describes an alternative technique to aid effective ligation of rotated teeth during the aligning stage of fixed appliance treatment. This technique has the potential to improve patient experience and confidence, by reducing the risk of trauma and discomfort and treatment efficiency, by ensuring complete ligation of even severely rotated teeth.

  3. Minimal Invasive Coronary Artery Fistula Ligation

    OpenAIRE

    Mitropoulos, Fotios A.; Kanakis, Meletios A.; Chatzis, Andrew; Contrafouris, Constantinos; Sofianidou, Ioanna A.; Lioulias, Achilleas G.

    2014-01-01

    A coronary artery fistula was surgically ligated in a 38-year-old woman via a left anterior mini-thoracotomy without the use of cardiopulmonary bypass. In selected cases, this surgical approach can provide an excellent surgical exposure for coronary artery fistula ligation. It also offers an excellent cosmetic result and shorter hospital stay.

  4. Bias in ligation-based small RNA sequencing library construction is determined by adaptor and RNA structure.

    Directory of Open Access Journals (Sweden)

    Ryan T Fuchs

    Full Text Available High-throughput sequencing (HTS has become a powerful tool for the detection of and sequence characterization of microRNAs (miRNA and other small RNAs (sRNA. Unfortunately, the use of HTS data to determine the relative quantity of different miRNAs in a sample has been shown to be inconsistent with quantitative PCR and Northern Blot results. Several recent studies have concluded that the major contributor to this inconsistency is bias introduced during the construction of sRNA libraries for HTS and that the bias is primarily derived from the adaptor ligation steps, specifically where single stranded adaptors are sequentially ligated to the 3' and 5'-end of sRNAs using T4 RNA ligases. In this study we investigated the effects of ligation bias by using a pool of randomized ligation substrates, defined mixtures of miRNA sequences and several combinations of adaptors in HTS library construction. We show that like the 3' adaptor ligation step, the 5' adaptor ligation is also biased, not because of primary sequence, but instead due to secondary structures of the two ligation substrates. We find that multiple secondary structural factors influence final representation in HTS results. Our results provide insight about the nature of ligation bias and allowed us to design adaptors that reduce ligation bias and produce HTS results that more accurately reflect the actual concentrations of miRNAs in the defined starting material.

  5. Electrodeposition and characterization of undoped and nitrogen-doped ZnSe films

    Energy Technology Data Exchange (ETDEWEB)

    Manzoli, A., E-mail: alexandra@cnpdia.embrapa.br [Institute of Chemistry of Sao Carlos (IQSC) - University of Sao Paulo (USP), P. O. Box 780, 13560-970, Sao Carlos, SP (Brazil); National Nanotechnology Laboratory for Agribusiness (LNNA), Embrapa Agricultural Instrumentation, P. O. Box 741, 13560-970, Sao Carlos, SP (Brazil); Eguiluz, K.I.B.; Salazar-Banda, G.R. [Institute of Chemistry of Sao Carlos (IQSC) - University of Sao Paulo (USP), P. O. Box 780, 13560-970, Sao Carlos, SP (Brazil); Institute of Technology and Research/University of Tiradentes, Av. Murilo Dantas, 300, 49032-490, Aracaju, SE (Brazil); Machado, S.A.S. [Institute of Chemistry of Sao Carlos (IQSC) - University of Sao Paulo (USP), P. O. Box 780, 13560-970, Sao Carlos, SP (Brazil)

    2010-05-15

    Semiconducting films of (n-type) ZnSe and (p-type) nitrogen-doped ZnSe were electrodeposited by a linear-sweep voltammetric technique on to a substrate of fluorine-tin oxide (FTO) glass ceramics. The films were characterized by scanning electron microscopy, energy-dispersive X-ray analysis and grazing-incidence X-ray diffraction. The results indicated that the material was deposited uniformly over the substrate, forming clusters when the Zn content of the bath was 0.1 mol L{sup -1} and a film when it was 0.2 or 0.3 mol L{sup -1}. The effectiveness of doping the films with nitrogen by adding ammonium sulfate to the deposition solution was assessed by measuring the film-electrolyte interface capacitance (C) at various applied potentials (E{sub ap}) and plotting Mott-Schottky curves (C{sup -2} vs E{sub ap}), whose slope sign was used to identify p-type ZnSe.

  6. Preparation and characterization of visible-light-active nitrogen-doped TiO2 photocatalyst

    Institute of Scientific and Technical Information of China (English)

    HUANG Xian-huai; TANG Yu-chao; HU Chun; YU Han-qing; CHEN Chu-sheng

    2005-01-01

    A visible-light photocatalyst was prepared by calcination of the hydrolysis product of Ti(SO4 )2 with ammonia as precipitator. The color of this photocatalyst was vivid yellow. It could absorb light under 550 nm wavelength. The crystal structure of anatase was characterized by XRD. The structure analysis result of X-ray fluorescence(XRF) shows that doped-nitrogen was presented in the sample.The photocatalytic activities were evaluated using methyl orange and phenol as model pollutants. The photocatalytic activities of samples were increasing gradually with calcination temperature from 400℃ to 700℃ under UV irradiation. It can be seen that the degradation of methyl orange follows zero-order kinetics. However, the calcination temperatures have no significant influence on the degradation of phenol under sunlight. The N-doped catalyst shows higher activity than the bare one under solar irradiation.

  7. Orchidopexy san ligation technique of orchidopexy

    Directory of Open Access Journals (Sweden)

    Jain Vishal

    2011-01-01

    Full Text Available Pediatric hernia surgery is the most common operation done by pediatric general surgeons and it is a core competency for general surgeons in the developing world. Herniotomy is performed for the surgical repair of hernia and along with orchiopexy for the closure of associated patent processus vaginalis. Traditionally, ligation of hernial sac during orchiopexy is considered mandatory to prevent postoperative development of hernia. The present report was designed to study the results of non-ligation of the hernial sac during orchiopexy. It was found that non-ligation has no untoward effect on early complications and recurrence rate on long-term follow-up. It is suggested that it is not necessary to ligate the hernial sac during orchiopexy in children.

  8. Preliminary characterization of nitrogen and phosphorus in groundwater discharging to Lake Spokane, northeastern Washington, using stable nitrogen isotopes

    Science.gov (United States)

    Gendaszek, Andrew S.; Cox, Stephen E.; Spanjer, Andrew R.

    2016-02-29

    Lake Spokane, locally referred to as Long Lake, is a 24-mile-long section of the Spokane River impounded by Long Lake Dam that has, in recent decades, experienced water-quality problems associated with eutrophication. Consumption of oxygen by the decomposition of aquatic plants that have proliferated because of high nutrient concentrations has led to seasonally low dissolved oxygen concentrations in the lake. Of nitrogen and phosphorus, the two primary nutrients necessary for aquatic vegetation growth, phosphorus was previously identified as the limiting nutrient that regulates the growth of aquatic plants and, thus, dissolved oxygen concentrations in Lake Spokane. Phosphorus is delivered to Lake Spokane from municipal and industrial point-source inputs to the Spokane River upstream of Lake Spokane, but is also conveyed by groundwater and surface water from nonpoint-sources including septic tanks, agricultural fields, and wildlife. In response, the Washington State Department of Ecology listed Lake Spokane on the 303(d) list of impaired water bodies for low dissolved oxygen concentrations and developed a Total Maximum Daily Load for phosphorus in 1992, which was revised in 2010 because of continuing algal blooms and water-quality concerns.This report evaluates the concentrations of phosphorus and nitrogen in shallow groundwater discharging to Lake Spokane to determine if a difference exists between nutrient concentrations in groundwater discharging to the lake downgradient of residential development with on-site septic systems and downgradient of undeveloped land without on-site septic systems. Elevated nitrogen isotope values (δ15N) within the roots of aquatic vegetation were used as an indicator of septic-system derived nitrogen. δ15N values were measured in August and September 2014 downgradient of residential development near the lakeshore, of residential development on 300-ft-high terraces above the lake, and of undeveloped land in the eastern (upper) and

  9. A comparative study of conventional ligation and self-ligation bracket systems.

    Science.gov (United States)

    Shivapuja, P K; Berger, J

    1994-11-01

    The increased use of self-ligating bracket systems frequently raises the question of how they compare with conventional ligation systems. An in vitro and clinical investigation was undertaken to evaluate and compare these distinctly different groups, by using five different brackets. The Activa ("A" Company, Johnson & Johnson, San Diego, Calif.), Edgelok (Ormco, Glendora, Calif.), and SPEED (Strite Industries Ltd., Cambridge, Ontario) self-ligating bracket systems displayed a significantly lower level of frictional resistance, dramatically less chairtime for arch wire removal and insertion, and promoted improved infection control, when compared with polyurethane elastomeric and stainless steel tie wire ligation for ceramic and metal twin brackets. PMID:7977187

  10. Melanin from the nitrogen-fixing bacterium Azotobacter chroococcum: a spectroscopic characterization.

    Directory of Open Access Journals (Sweden)

    Aulie Banerjee

    Full Text Available Melanins, the ubiquitous hetero-polymer pigments found widely dispersed among various life forms, are usually dark brown/black in colour. Although melanins have variety of biological functions, including protection against ultraviolet radiation of sunlight and are used in medicine, cosmetics, extraction of melanin from the animal and plant kingdoms is not an easy task. Using complementary physicochemical techniques (i.e. MALDI-TOF, FTIR absorption and cross-polarization magic angle spinning solid-state (13C NMR, we report here the characterization of melanins extracted from the nitrogen-fixing non-virulent bacterium Azotobacter chroococcum, a safe viable source. Moreover, considering dihydroxyindole moiety as the main constituent, an effort is made to propose the putative molecular structure of the melanin hetero-polymer extracted from the bacterium. Characterization of the melanin obtained from Azotobacter chroococcum would provide an inspiration in extending research activities on these hetero-polymers and their use as protective agent against UV radiation.

  11. Characterization of the surface properties of nitrogen-enriched carbons by inverse gas chromatography methods

    Energy Technology Data Exchange (ETDEWEB)

    Vagner, C.; Finqueneisel, G.; Zimny, T.; Burg, P.; Grzyb, B.; Machnikowski, J.; Weber, J.V. [University of Metz, St. Avold (France)

    2003-07-01

    The characterization of the surface properties of carbonaceous materials by inverse gas chromatography (IGC) techniques is described. The cokes investigated were produced by the co-pyrolysis of a coal-tar pitch (CTP) with different amounts of polyacrylonitrile (PAN) as a possible method to synthesize carbonaceous materials enriched in nitrogen. IGC at infinite dilution and LSER (linear solvation energy relationship) techniques were used to determine the physical and chemical surface properties of the cokes. In general, the surface free energy of adsorption is due to both dispersive and specific interactions. The dispersive component of the surface free energy was determined using n-alkane probes. For the specific component, which is primarily due to acid-base interactions, different polar probes were used. The LSER method was applied to improve our understanding of the adsorption process in terms of molecular interactions. We show that, to characterize dispersive interactions using n-alkanes, the LSER and IGC methods are equivalent. On the other hand, with both methods we find that all the samples present acidic and basic characteristics. However, the sensitivity of the LSER method does not allow one to discriminate between the three samples in terms of specific interactions.

  12. Synthesis and characterization of well-aligned carbon nitrogen nanotubes by microwave plasma chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Well-aligned carbon nitrogen nanotube films have been synthesized successfully on mesoporous silica substrates by microwave plasma chemical vapor deposition (MWPCVD) method. Studies on their morphology, structure, and composition by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX), respectively, indicate that these nanotubes consist of linearly polymerized carbon nitrogen nanobells, and the nitrogen atoms have been doped into carbon netweork to form a new structure C1-xNx (x=0.16±0.01). X-ray photoelectron spectroscopy (XPS) results of the samples further demonstrate that carbon bonds covalently with nitrogen in all the carbon nitrogen nanotube films.

  13. Blood flow changes after unilateral carotid artery ligation monitored by optical coherence tomography

    Science.gov (United States)

    Ma, Yushu; Liang, Chengbo; Suo, Yanyan; Zhao, Yuqian; Wang, Yi; Xu, Tao; Wang, Ruikang; Ma, Zhenhe

    2016-03-01

    Unilateral carotid artery ligation which could induce adaptive improvement is a classic model that has been widely used to study pathology of ischemic disease. In those studies, blood flow is an important parameter to characterize the ischemia. Optical coherence tomography (OCT) is a powerful imaging modality which can provide depth resolved images in biological tissue with high spatial and temporal resolution. SPF rats was anesthetized with isoflurane and divided into two groups. In first group, bilateral carotid artery was surgically exposed, and then left carotid artery was ligated. Blood flow changes of the contralateral carotid artery was monitored using high speed spectral domain optical coherence tomography, including the absolute flow velocity and the flow volume. In the other group, skull window was opened at the ipsilateral cerebral cortex of ligation and blood supply of small artery was measured before and after the ligation. The measured results demonstrate the blood supply compensation process after unilateral carotid artery ligation. With the superiority of high resolution, OCT is an effective technology in monitoring results of carotid artery after ligation.

  14. Genome-wide identification and characterization of novel lncRNAs in Populus under nitrogen deficiency.

    Science.gov (United States)

    Chen, Min; Wang, Chenlu; Bao, Hai; Chen, Hui; Wang, Yanwei

    2016-08-01

    Long non-coding RNAs (lncRNAs) have been identified as important regulatory factors of gene expression in eukaryotic species, such as Homo sapiens, Arabidopsis thaliana, and Oryza sativa. However, the systematic identification of potential lncRNAs in trees is comparatively rare. In particular, the characteristics, expression, and regulatory roles of lncRNAs in trees under nutrient stress remain largely unknown. A genome-wide strategy was used in this investigation to identify and characterize novel and low-nitrogen (N)-responsive lncRNAs in Populus tomentosa; 388 unique lncRNA candidates belonging to 380 gene loci were detected and only seven lncRNAs were found to belong to seven conserved non-coding RNA families indicating the majority of P. tomentosa lncRNAs are species-specific. In total, 126 lncRNAs were significantly altered under low-N stress; 8 were repressed, and 118 were induced. Furthermore, 9 and 5 lncRNAs were detected as precursors of 11 known and 14 novel Populus miRNAs, respectively, whereas 4 lncRNAs were targeted by 29 miRNAs belonging to 5 families, including 22 conserved and 7 non-conserved miRNAs. In addition, 15 antisense lncRNAs were identified to be generated from opposite strands of 14 corresponding protein-coding genes. In total, 111 protein-coding genes with regions complementary to 38 lncRNAs were also predicted with some lncRNAs corresponding to multiple genes and vice versa, and their functions were annotated, which further demonstrated the complex regulatory relationship between lncRNAs and protein-coding genes in plants. Moreover, an interaction network among lncRNAs, miRNAs, and mRNAs was investigated. These findings enrich our understanding of lncRNAs in Populus, expand the methods of miRNA identification. Our results present the first global characterization of lncRNAs and their potential target genes in response to nitrogen stress in trees, which provides more information on low-nutrition adaptation mechanisms in woody plants

  15. Characterizing the transformation and transfer of nitrogen during the aerobic treatment of organic wastes and digestates

    Energy Technology Data Exchange (ETDEWEB)

    Zeng Yang, E-mail: yang.zeng@irstea.fr [Irstea, UR GERE, 17 avenue de Cucille, CS 64427, F-35044 Rennes Cedex (France); Universite Europeenne de Bretagne, F-35000 Rennes (France); Guardia, Amaury de; Daumoin, Mylene; Benoist, Jean-Claude [Irstea, UR GERE, 17 avenue de Cucille, CS 64427, F-35044 Rennes Cedex (France)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Ammonia emissions varied depending on the nature of wastes and the treatment conditions. Black-Right-Pointing-Pointer Nitrogen losses resulted from ammonia emissions and nitrification-denitrification. Black-Right-Pointing-Pointer Ammonification can be estimated from biodegradable carbon and carbon/nitrogen ratio. Black-Right-Pointing-Pointer Ammonification was the main process contributing to N losses. Black-Right-Pointing-Pointer Nitrification rate was negatively correlated to stripping rate of ammonia nitrogen. - Abstract: The transformation and transfer of nitrogen during the aerobic treatment of seven wastes were studied in ventilated air-tight 10-L reactors at 35 Degree-Sign C. Studied wastes included distinct types of organic wastes and their digestates. Ammonia emissions varied depending on the kind of waste and treatment conditions. These emissions accounted for 2-43% of the initial nitrogen. Total nitrogen losses, which resulted mainly from ammonia emissions and nitrification-denitrification, accounted for 1-76% of the initial nitrogen. Ammonification was the main process responsible for nitrogen losses. An equation which allows estimating the ammonification flow of each type of waste according to its biodegradable carbon and carbon/nitrogen ratio was proposed. As a consequence of the lower contribution of storage and leachate rates, stripping and nitrification rates of ammonia nitrogen were negatively correlated. This observation suggests the possibility of promotingnitrification in order to reduce ammonia emissions.

  16. Characterization of nitrogen-rich biomaterial-derived biochars and their sorption for aromatic compounds.

    Science.gov (United States)

    Zhang, Meng; Shu, Liang; Shen, Xiaofang; Guo, Xiaoying; Tao, Shu; Xing, Baoshan; Wang, Xilong

    2014-12-01

    Biochars from nitrogen-rich biomaterials (i.e., α-amylase, chitin and zein) were produced at different temperatures (i.e. 170, 250, 350 and 450 °C) and characterized, and their sorption for phenanthrene, naphthalene and 1-naphthol was investigated. The organic carbon content normalized-sorption coefficient (Koc) of the tested compounds by biochars increased with increasing charring temperature, attributed to the reduction of O-containing polar moieties especially the O-alkyl components, and the newly created aromatic carbon domains. The N-heterocyclic ring structure formed during charring process may enhance π-π interactions between aromatics and the aromatic components in the resulting biochars. However, π-π interactions did not dominate sorption of aromatics by N-rich biochars. Sorption of the tested compounds by N-rich biochars was predominantly controlled by the hydrophobic interactions between these chemicals and the aromatic components in biochars. Both N- and O-containing polar moieties at the biochar surfaces negatively affected their sorption for aromatics.

  17. Modification and characterization of a high-energy photon irradiation facility using nitrogen-16

    Science.gov (United States)

    Roy, Tapash Kumar

    This work involves fabrication and characterization of a reactor source of high energy (˜7 MeV) nitrogen-16 photons for application in evaluation of dosimetric responses of personnel devices and portable instruments. The N-16 source has been established by continuously flowing coolant water from the core of a 1 MW research reactor through a cylindrical thin walled aluminium chamber. Dose measurements have been made at selected distances of interest along the depth axis both for with and without a near-air equilibrium wall of polymethyl methacrylate (PMMA) in place. Photon dose and exposure measurements were done using condenser-R ionization chambers with sufficiently thick walls to yield an approximate transient charged particle equilibrium (TCPE) condition. Field areal uniformity was defined using large area Kodak Readypack RP films along with lead foil radiators. Dosimetric quantities of interest include skin dose, eye (lens) dose, and 1 cm deep dose. Measurements were made at selected depths of 7, 300, and 1000 mg cm-2 for specific evaluation of these respective quantities. Photon spectral analysis was performed with a NaI(Tl) scintillation spectrometry system. Additionally, beta radiation measurements, and evaluation of neutron dose contributions to the radiation field were completed.

  18. Characterization of nitrogen adsorption isotherms of thermally-treated organoclays using multifractal analysis

    Science.gov (United States)

    Lado, Marcos; Borisover, Mikhail; Paz-Gonzalez, Antonio

    2013-04-01

    Nitrogen adsorption isotherms of soils have been reported to exhibit multifractal behavior. In the present work, multifractal analysis is used to characterize changes in N2 adsorption isotherms of organoclays prepared with different cations and exposed to various thermal treatments. Wyoming bentonite was exchanged with benzyltrimethylammonium (BTMA-clay), tetraethylammonium (TEA-clay), and hexadecyltrimethylammonium exchanged at 41 and 90% of the cation exchange capacity of the clay (HDTMA41- and HDTMA90-clay). The resulting organoclays were exposed to temperatures ranging from 25 to 420°C during two hours, freeze-dried, and N2 adsorption isotherms were measured at 77°K. The obtained isotherms showed multifractal behavior, and parameters derived from Rényi and singularity spectra varied with changes in the organic cation and the treatment temperature. The type of cation was the dominant factor responsible for changes in spectra, and significant interactions were observed between type of cation and temperature for several parameters. Significant correlations were found between organic carbon content and multifractal parameters, indicating a relation between changes in N2 sorption sites and thermal transformations of the organic cations. Significant correlations were also found between some multifractal parameters and the heterogeneity exponent of a Freundlich model fitted to nitrobenzene isotherms measured in the organoclays, suggesting that multifractal analysis of N2 adsorption isotherms could be useful to analyze the heterogeneity of sorption sites when sorption determinations yield a limited amount of data.

  19. Nitrogen-15 NMR characterization of the neutral form of 7-methylguanosine

    Energy Technology Data Exchange (ETDEWEB)

    Barbarella, G. (CNR, Bologna (Italy)); Bertoluzza, A.; Tugnoli, V. (Sezione di Chimica e Propedeutica Biochimica, Bologna (Italy))

    1988-07-25

    The commercial 7-methylguanosine used for several physico-chemical studies, and prepared by methylation of the parent guanosine, is a mixture of the neutral and the protonated forms, as shown by carbon-13 and nitrogen-15 NMR. Nitrogen-15 chemical shifts of the neutral and the protonated forms of 7-methylguanosine are shown.

  20. Synthesis and characterization of well-aligned carbon nitrogen nanotubes by microwave plasma chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    马旭村; 徐贵昌; 王恩哥

    2000-01-01

    Well-aligned carbon nitrogen nanotube films have been synthesized successfully on meso-porous silica substrates by microwave plasma chemical vapor deposition (MWPCVD) method. Studies on their morphology, structure, and composition by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX), respectively, indicate that these nanotubes consist of linearly polymerized carbon nitrogen nanobells, and the nitrogen atoms have been doped into carbon netweork to form a new structure C1-xNx( x = 0.16±0.01). X-ray photoelectron spectroscopy (XPS) results of the samples further demonstrate that carbon bonds cova-lently with nitrogen in all the carbon nitrogen nanotube films.

  1. Tubal ligation and risk of breast cancer

    OpenAIRE

    Brinton, L. A.; Gammon, M. D.; Coates, R J; Hoover, R. N.

    2000-01-01

    Although it has been demonstrated in previous studies that tubal ligation can have widespread effects on ovarian function, including a decrease in the risk of subsequent ovarian cancer, few studies have evaluated effects on breast cancer risk. In a population-based case–control study of breast cancer among women 20–54 years of age conducted in three geographic areas, previous tubal ligations were reported by 25.3% of the 2173 cases and 25.8% of the 1990 controls. Initially it appeared that tu...

  2. Enzymatic Ligation of Large Biomolecules to DNA

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Schøler; Okholm, Anders Hauge; Schaffert, David Henning;

    2013-01-01

    application. However, conjugation of DNA to large molecular components using classical chemistries often suffers from suboptimal yields. Here, we report the use of terminal deoxynucleotidyl transferase (TdT) for direct enzymatic ligation of native DNA to nucleotide triphosphates coupled to proteins and other...... large macromolecules. We demonstrate facile synthesis routes for a range of NTP-activated macromolecules and subsequent ligation to the 3′ hydroxyl group of oligodeoxynucleotides using TdT. The reaction is highly specific and proceeds rapidly and essentially to completion at micromolar concentrations...

  3. Increasing the efficiency of SAGE adaptor ligation by directed ligation chemistry

    Science.gov (United States)

    So, Austin P.; Turner, Robin F. B.; Haynes, Charles A.

    2004-01-01

    The ability of Serial Analysis of Gene Expression (SAGE) to provide a quantitative picture of global gene expression relies not only on the depth and accuracy of sequencing into the SAGE library, but also on the efficiency of each step required to generate the SAGE library from the starting mRNA material. The first critical step is the ligation of adaptors containing a Type IIS recognition sequence to the anchored 3′ end cDNA population that permits the release of short sequence tags (SSTs) from defined sites within the 3′ end of each transcript. Using an in vitro transcript as a template, we observed that only a small fraction of anchored 3′ end cDNA are successfully ligated with added SAGE adaptors under typical reaction conditions currently used in the SAGE protocol. Although the introduction of ∼500-fold molar excess of adaptor or the inclusion of 15% (w/v) PEG-8000 increased the yield of the adaptor-modified product, complete conversion to the desired adaptor:cDNA hetero-ligation product is not achieved. An alternative method of ligation, termed as directed ligation, is described which exploits a favourable mass-action condition created by the presence of NlaIII during ligation in combination with a novel SAGE adaptor containing a methylated base within the ligation site. Using this strategy, we were able to achieve near complete conversion of the anchored 3′ end cDNA into the desired adaptor-modified product. This new protocol therefore greatly increases the probability that a SST will be generated from every transcript, greatly enhancing the fidelity of SAGE. Directed ligation also provides a powerful means to achieve near-complete ligation of any appropriately designed adaptor to its respective target. PMID:15247329

  4. Synthesis and characterization of nitrogen-doped graphene films using C5NCl5

    International Nuclear Information System (INIS)

    To modify the electrical properties of graphene, we have synthesized nitrogen-doped graphene films using pentachloropyridine and methane by a two-step growth process with the N/C ratio of 2.5%–4%. The nitrogen-doped graphene presoma synthesized at 350 °C can be transformed into nitrogen-doped graphene fragments by annealing at 1000 °C. The introduction of methane as a second carbon source plays a key role in the formation of continuous uniform nitrogen-doped graphene films. The as-obtained N-doped graphene films exhibit n-type conduction with the electron mobility and density of 375 cm2 V−1 s−1 and 2.38 × 1013 cm−2 at room temperature, respectively

  5. Synthesis and Characterization of Mesoporous Silicon Oxynitride MCM-41 with High Nitrogen Content

    Institute of Scientific and Technical Information of China (English)

    ZHANG Cunman; XU Zheng; LIU Qian

    2005-01-01

    Mesoporous silicon oxynitrides MCM-41 were synthesized successfully. The resulting materials not only have high nitrogen contents and good structural characteristics of MCM-41 (high surface area, narrow pore size distribution and good order), but also are amorphous. The composition and structure of the materials were investigated by CNH element analysis, XPS, Si MAS NMR, XRD, HRTEM and N2 sorption, respectively. Mesoporous silicon oxynitrides MCM-41 with a high nitrogen content are still non-crystal (amorphous).

  6. Hydrogels Formed by Oxo-ester Mediated Native Chemical Ligation

    OpenAIRE

    Strehin, Iossif; Gourevitch, Dmitri; Zhang, Yong; Heber-Katz, Ellen; Messersmith, Phillip B.

    2013-01-01

    Oxo-ester mediated native chemical ligation (OMNCL) is a variation of the more general native chemical ligation (NCL) reaction that is widely employed for chemoselective ligation of peptide fragments. While OMNCL has been used for a variety of peptide ligations and for biomolecular modification of surfaces, it is typically practiced under harsh conditions that are unsuitable for use in a biological context. In this report we describe the use of OMNCL for polymer hydrogel formation, in-vitro c...

  7. Synergetic inhibition of thermochemical formation of chlorinated aromatics by sulfur and nitrogen derived from thiourea: Multielement characterizations.

    Science.gov (United States)

    Fujimori, Takashi; Nakamura, Madoka; Takaoka, Masaki; Shiota, Kenji; Kitajima, Yoshinori

    2016-07-01

    Nitrogen and sulfur (N/S)-containing compounds inhibit the formation of polychlorinated dibenzo-p-dioxins (PCDDs) and furans (PCDFs) in thermal processes. However, few studies have examined the inhibition mechanisms of N/S-containing compounds. In the present study, we focused on thiourea [(NH2)2CS] as such a compound and investigated its inhibition effects and mechanisms. The production of PCDD/Fs, polychlorinated biphenyls (PCBs), and chlorobenzenes (CBzs) were inhibited by >99% in the model fly ash in the presence of 1.0% thiourea after heating at 300°C. Experimental results using real fly ash series were indicative of the thermal destruction of these chlorinated aromatics by thiourea. Multielement characterization using K-edge X-ray absorption fine structures of copper, chlorine, sulfur, nitrogen, and carbon revealed three possible inhibition paths, namely, (a) sulfidization of the copper catalyst to CuS, Cu2S, and CuSO4; (b) blocking the chlorination of carbon via the reaction of chlorine with N-containing compounds to generate ammonium chloride and other minor compounds; and (c) changing the carbon frame involved in attacking the carbon matrix by sulfur and nitrogen. Thus, thiourea plays a role as a sulfur and nitrogen donor to achieve multiple and synergistic inhibition of chlorinated aromatics. Our results suggest that other N/S-containing inhibitors function based on similar mechanisms. PMID:26954475

  8. Synergetic inhibition of thermochemical formation of chlorinated aromatics by sulfur and nitrogen derived from thiourea: Multielement characterizations.

    Science.gov (United States)

    Fujimori, Takashi; Nakamura, Madoka; Takaoka, Masaki; Shiota, Kenji; Kitajima, Yoshinori

    2016-07-01

    Nitrogen and sulfur (N/S)-containing compounds inhibit the formation of polychlorinated dibenzo-p-dioxins (PCDDs) and furans (PCDFs) in thermal processes. However, few studies have examined the inhibition mechanisms of N/S-containing compounds. In the present study, we focused on thiourea [(NH2)2CS] as such a compound and investigated its inhibition effects and mechanisms. The production of PCDD/Fs, polychlorinated biphenyls (PCBs), and chlorobenzenes (CBzs) were inhibited by >99% in the model fly ash in the presence of 1.0% thiourea after heating at 300 °C. Experimental results using real fly ash series were indicative of the thermal destruction of these chlorinated aromatics by thiourea. Multielement characterization using K-edge X-ray absorption fine structures of copper, chlorine, sulfur, nitrogen, and carbon revealed three possible inhibition paths, namely, (a) sulfidization of the copper catalyst to CuS, Cu2S, and CuSO4; (b) blocking the chlorination of carbon via the reaction of chlorine with N-containing compounds to generate ammonium chloride and other minor compounds; and (c) changing the carbon frame involved in attacking the carbon matrix by sulfur and nitrogen. Thus, thiourea plays a role as a sulfur and nitrogen donor to achieve multiple and synergistic inhibition of chlorinated aromatics. Our results suggest that other N/S-containing inhibitors function based on similar mechanisms.

  9. Artery ligation in the treatment of hemorrhoidal disease

    NARCIS (Netherlands)

    Schuurman, J.P.

    2012-01-01

    The aim of this thesis was to study the working principle in relation to the outcome of the artery ligation procedure; a treatment for hemorrhoidal disease. Hemorrhoidal artery ligation, known as HAL (hemorrhoidal artery ligation) or THD (transanal hemorrhoidal dearterialization) procedure, is a c

  10. Characterization of transient discharges under atmospheric pressure conditions applying nitrogen photoemission and current measurements

    CERN Document Server

    Keller, Sandra; Bibinov, Nikita; Awakowicz, Peter

    2011-01-01

    Plasma parameters of three transient discharges (filamentary and homogeneous dielectric barrier discharges in air, and the spark discharge of an argon plasma coagulator) operated at atmospheric pressure conditions are determined applying a combination of diagnostics methods, namely numerical simulation, current measurement, and optical emission spectroscopy. These diagnostic methods supplement each other and resolve problems, which arise when these methods are used separately. Nitrogen is used as sensor gas and is admixed to argon for studying the argon plasma coagulator. The Boltzmann equation is solved in 'local' approximation to determine electron velocity distribution function. Drift velocity, electron-impact excitation rate constants for nitrogen molecular emission, electric current density, and emission spectrum of nitrogen molecule are calculated. Plasma parameters (electron velocity distribution function and electron density) are determined applying calculated as far as measured electric current, and ...

  11. Facile synthesis, characterization and antimicrobial activities of diphenylphosphoryl derivatives of substituted aryl and nitrogen heterocycles

    Directory of Open Access Journals (Sweden)

    G. Subba Reddy

    2013-03-01

    Full Text Available Diphenylphosphoryl derivatives of substituted aryl and nitrogen heterocycles were prepared by a one-pot process involving sequential reaction of diphenylphosphine chloride with dry methyl alcohol/ethyl alcohol and then with different halides of substituted nitrogen heterocycles/aryl halides. The title compounds (5a-j structures were established by analytical, IR, NMR ( 1H, 13C and 31P and mass spectra, and they have been screened for their antimicrobial activity. They exhibited significant antibacterial and antifungal activity.

  12. Development of hepatorenal syndrome in bile duct ligated rats

    Institute of Scientific and Technical Information of China (English)

    Regina M Pereira; Ana Cristina Sim(o)es e Silva; Robson AS dos Santos; Eduardo A Oliveira; Virg(i)nia HR Leite; Filipi LC Dias; Alysson S Rezende; Lincoln P Costa; Luciola S Barcelos; Mauro M Teixeira

    2008-01-01

    AIM: To evaluate in bile duct ligated rats whether there were progressive alterations of renal function without changes in histopathology.METHODS: Male Wistar rats were submitted to sham-surgery or bile duct ligation (BDL) and divided according to the post-procedure time (2, 4 and 6-wk).To determine renal function parameters, rats were placed in metabolic cages and, at the end of the experiment, blood and urine samples were obtained.Histology and hydroxyproline content were analyzed in liver and renal tissue.RESULTS: Rats with 2 wk of BDL increased free water clearance (P = 0.02), reduced urinary osmolality (P =0.03) and serum creatinine (P = 0.01) in comparison to the sham group. In contrast, rats at 6 wk of BDL showed features of HRS, including significant increase in serum creatinine and reductions in creatinine clearance,water excretion and urinary sodium concentration. Rats with 4 wk of BDL exhibited an intermediate stage of renal dysfunction. Progressive hepatic fibrosis according to post-procedure time was confirmed by histology.The increased levels of liver hydroxyproline contrasted with the absence of structural changes in the kidney, as assessed by histology and unchanged hydroxyproline content in renal tissue.CONCLUSION: Our data show that BDL produced progressive renal dysfunction without structural changes in the kidney, characterizing HRS. The present model will be useful to understand the pathophysiology of HRS.

  13. Isolation and characterization of a mutant defective in triacylglycerol accumulation in nitrogen-starved Chlamydomonas reinhardtii.

    Science.gov (United States)

    Hung, Chun-Hsien; Kanehara, Kazue; Nakamura, Yuki

    2016-09-01

    Triacylglycerol (TAG), a major source of biodiesel production, accumulates in nitrogen-starved Chlamydomonas reinhardtii. However, the metabolic pathway of starch-to-TAG conversion remains elusive because an enzyme that affects the starch degradation is unknown. Here, we isolated a new class of mutant bgal1, which expressed an overaccumulation of starch granules and defective photosynthetic growth. The bgal1 was a null mutant of a previously uncharacterized β-galactosidase-like gene (Cre02.g119700), which decreased total β-galactosidase activity 40% of the wild type. Upon nitrogen starvation, the bgal1 mutant showed decreased TAG accumulation mainly due to the reduced flux of de novo TAG biosynthesis evidenced by increased unsaturation of fatty acid composition in TAG and reduced TAG accumulation by additional supplementation of acetate to the culture media. Metabolomic analysis of the bgal1 mutant showed significantly reduced levels of metabolites following the hydrolysis of starch and substrates for TAG accumulation, whereas metabolites in TCA cycle were unaffected. Upon nitrogen starvation, while levels of glucose 6-phosphate, fructose 6-phosphate and acetyl-CoA remained lower, most of the other metabolites in glycolysis were increased but those in the TCA cycle were decreased, supporting TAG accumulation. We suggest that BGAL1 may be involved in the degradation of starch, which affects TAG accumulation in nitrogen-starved C. reinhardtii. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner. PMID:27060488

  14. A tool based on Ligation Detection Reaction-Universal Array (LDR-UA) for the characterization of VTEC by identification of virulence-associated and serogroup-specific genes.

    Science.gov (United States)

    Lauri, Andrea; Castiglioni, Bianca; Morabito, Stefano; Tozzoli, Rosangela; Consolandi, Clarissa; Mariani, Paola

    2011-02-01

    Verocytoxigenic Escherichia coli (VTEC) are zoonotic pathogens whose natural reservoir is represented by ruminants, particularly cattle. Infections are mainly acquired by consumption of undercooked contaminated food of animal origin, contact with infected animals and contaminated environment. VTEC O157 is the most frequently isolated serogroup from cases of human disease, however, other VTEC serogroups, such as O26, O111, O145 and O103, are increasingly reported as causing Hemolytic Uremic Syndrome (HUS) worldwide. The identification of VTEC is troublesome, hindering the development of effective prevention strategies. In fact, VTEC are morphologically indistinguishable from harmless E. coli and their pathogenic potential is not strictly dependent on the serogroup, but relies on the presence of a collection of virulence genes. We developed a diagnostic tool for VTEC based on the Ligation Detection Reaction coupled to Universal Array (LDR-UA) for the simultaneous identification of virulence factors and serogroup-associated genes. The method includes the investigation of 40 sites located in 13 fragments from 12 genes (sodCF1/F2, adfO, terB, ehxA, eae, vtx1, vtx2, ihp1, wzx, wbdI, rfbE, dnaK) and was evaluated by performing a trial on a collection of 67 E. coli strains, both VTEC and VT-negative E. coli, as well as on 25 isolates belonging to other related species. Results of this study showed that the LDR-UA technique was specific in identifying the target microorganism. Moreover, due to its higher throughput, the LDR-UA can be a valid and cheaper alternative to real time PCR-based (rt-PCR) methods for VTEC identification.

  15. Cost saving by reloading the multiband ligator in endoscopic esophageal variceal ligation: A proposal for developing countries

    Institute of Scientific and Technical Information of China (English)

    Zaigham Abbas; Lubna Rizvi; Umair Syed Ahmed; Khalid Mumtaz; Wasim Jafri

    2008-01-01

    AIM: To assess the cost savings of reloading the multiband ligator in endoscopic esophageal variceal ligation (EVL) used on the same patient for subsequent sessions,METHODS: This single centre retrospective descriptive study analysed patients undergoing variceal ligation at a tertiary care centre between 1st January, 2003 and 30th June, 2006. The multiband ligator was reloaded with six hemorrhoidal bands using hemorrhoidal ligator for the second and subsequent sessions. Analysis of cost saving was done for the number of follow-up sessions for the variceal eradication.RESULTS: A total of 261 patients underwent at least one session of endoscopic esophageal variceal ligation between January 2003 and June 2006. Out of 261, 108 patients (males 67) agreed to follow the eradication program and underwent repeated sessions. A total of 304 sessions was performed with 2.81 sessions per patient on average. Thirty-two patients could not complete the programm. In 76 patients (70%), variceal obliteration was achieved. The ratio of the costs for the session with reloaded ligator versus a session with a new ligator was 1:2.37. Among the patients who completed esophageal varices eradication, cost saving with reloaded ligator was 58%.CONCLUSION: EVL using reloaded multiband ligators for the follow-up sessions on patients undergoing variceal eradication is a cost saving procedure. Reloading the ligator thus is recommended especially for developing countries where most of the patients are not health insured.

  16. New nitrogen-containing materials for hydrogen storage and their characterization by high-pressure microbalance

    DEFF Research Database (Denmark)

    Vestbø, Andreas Peter

    or liquid form, technologies that are well developed and usable, but not energy efficient. Certain metals and alloys are able to contain hydrogen within practical pressure and temperature ranges very efficient volume-wise, but they are too heavy for use in cars. Recently, attention has turned to the so......-called complex hydrides, which contain hydrogen bound covalently often in very light materials involving elements such as lithium, sodium, nitrogen and aluminum. While these materials typically have high decomposition temperatures, the combination with other compounds helps to destabilize the material resulting...... in lowered effective dehydrogenation temperatures. From the discovery in 1996 by Borislav Bogdanović and his group that catalyzed sodium alanate, NaAlH4, can release hydrogen reversibly below 200 °C relatively fast, hydrogen storage in nitrogen-containing compounds beginning with lithium nitride, Li3N...

  17. Characterization of humus microbial communities in adjacent forest types that differ in nitrogen availability.

    Science.gov (United States)

    Leckie, S E; Prescott, C E; Grayston, S J; Neufeld, J D; Mohn, W W

    2004-07-01

    To address the link between soil microbial community composition and soil processes, we investigated the microbial communities in forest floors of two forest types that differ substantially in nitrogen availability. Cedar-hemlock (CH) and hemlock-amabilis fir (HA) forests are both common on northern Vancouver Island, B.C., occurring adjacently across the landscape. CH forest floors have low nitrogen availability and HA high nitrogen availability. Total microbial biomass was assessed using chloroform fumigation-extraction and community composition was assessed using several cultivation-independent approaches: denaturing gradient gel electrophoresis (DGGE) of the bacterial communities, ribosomal intergenic spacer analysis (RISA) of the bacterial and fungal communities, and phospholipid fatty acid (PLFA) profiles of the whole microbial community. We did not detect differences in the bacterial communities of each forest type using DGGE and RISA, but differences in the fungal communities were detected using RISA. PLFA analysis detected subtle differences in overall composition of the microbial community between the forest types, as well as in particular groups of organisms. Fungal PLFAs were more abundant in the nitrogen-poor CH forests. Bacteria were proportionally more abundant in HA forests than CH in the lower humus layer, and Gram-positive bacteria were proportionally more abundant in HA forests irrespective of layer. Bacterial and fungal communities were distinct in the F, upper humus, and lower humus layers of the forest floor and total biomass decreased in deeper layers. These results indicate that there are distinct patterns in forest floor microbial community composition at the landscape scale, which may be important for understanding nutrient availability to forest vegetation.

  18. Identification and characterization of land use driven nitrogen fluxes using stable isotopes and reactive hydrologic modeling

    Science.gov (United States)

    Macko, S. A.; O'Connell, M. T.

    2015-12-01

    The Najinhe watershed is a topographically diverse, mixed agricultural and urban region in northeastern China that provides opportunities for identification of the impact of land use on nitrogen cycling. In addition to agricultural soil amendments, seasonal variation in atmospheric flow introduces dry and wet deposition from urban and desert sources. Both agricultural amendments and atmospheric sources are significant non-point inputs of reactive N, at estimated annual rates of 450 kg/ha and 30 kg/ha respectively in the nearby North China Plain.Both historic and current land use has influenced the biological processing of nitrogen in a particular area. Soil conditions, including moisture, texture, and organic content, control the capacity of a parcel for processing reactive nitrogen. Compounds derived from natural and anthropogenic sources exhibit characteristic stable isotopes of nitrogen and oxygen that serve as tracers of origin as well as integrators of biological processes. Analysis of bulk soils (including both organic and inorganic N contents) in the system shows δ15N ranging from 1.3 - 8.6 ‰ suggesting varying influence of anthropogenic inputs, fertilizers, soil organic nitrogen, and atmospheric sources based on land use.A distributed hydrologic model coupled with one focusing on reactive transport is able to help determine locations with the highest impact on the dissolved N in this system. Spatial statistical methods are employed to determine the biogeochemical influence of model locations whereas δ18O on soil NO3- and δ15N measurements on NO3- and NH4+ in surface water and soil extracts are used to calibrate and validate model predictions based on measured precipitation and streamflow values. Sources are integrated using a Bayesian mixing model to determine likely fate and transport parameters for various N inputs to the watershed. The application of the coupled hydrologic and transport models to a landscape scale catchment suggests integration and

  19. Laboratory Investigations of Titan Haze Formation: Characterization of Gas Phase and Particle Phase Nitrogen

    Science.gov (United States)

    Horst, Sarah; Yoon, Heidi; Li, Rui; deGouw, Joost; Tolbert, Margaret

    2014-11-01

    Prior to the arrival of the Cassini-Huygens spacecraft, aerosol production in Titan’s atmosphere was believed to begin in the stratosphere where chemical processes are predominantly initiated by far ultraviolet (FUV) radiation. However, the discovery of very heavy ions, coupled with Cassini Ultraviolet Imaging Spectrograph (UVIS) occultation measurements that show haze absorption up to 1000 km altitude (Liang et al., 2007), indicates that haze formation initiates in the thermosphere. The energy environment of the thermosphere is significantly different from the stratosphere; in particular there is a greater flux of extreme ultraviolet (EUV) photons and energetic particles available to initiate chemical reactions, including the destruction of N2, in the upper atmosphere. The discovery of previously unpredicted nitrogen species in measurements of Titan’s atmosphere by the Cassini Ion and Neutral Mass Spectrometer (INMS) indicates that nitrogen participates in the chemistry to a much greater extent than was appreciated before Cassini (Vuitton et al., 2007). Additionally, measurements obtained by the Aerosol Collector Pyrolyzer (ACP) carried by Huygens to Titan’s surface may indicate that Titan’s aerosols contain significant amounts of nitrogen (Israël et al., 2005, 2006). The degree of nitrogen incorporation in the haze particles is important for understanding the diversity of molecules that may be present in Titan’s atmosphere and on its surface. We have conducted a series of Titan atmosphere simulation experiments using either spark discharge (tesla coil) or FUV photons (deuterium lamp) to initiate chemistry in CH4/N2 gas mixtures ranging from 0.01% CH4/99.99% N2 to 10% CH4/90% N2. We obtained in situ measurements using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) to measure the particle composition as a function of particle size and a proton-transfer ion-trap mass spectrometer (PIT-MS) to measure the composition of gas phase

  20. Experimental investigation and characterization of a compact pulsed tea molecular nitrogen laser

    International Nuclear Information System (INIS)

    A locally assembled compact nitrogen laser with a Blumlein configuration is investigated. Parameters unique to the laser such as laser tube inductance, spark gap inductance, the characteristic impedance of the transmission line, the charging voltage, the laser optical pulse width, the electrical peak power input into the laser, and the optical peak power from the laser pulse are measured. To initiate the discharge, a compact high-voltage 13-25 kilovolt switching power supply was constructed. A 45 kilovolt pulse generator was necessary, so a trigerring device was also made. For high voltage measurements, a 300 turn Rogowski coil was used. Similarly a high voltage magnetic probe consisting of number 30 AWG wire wound around a 1mm bobbin and encapsulated in glass was constructed. Calibration of the probe was done using an 18-turn Helmholtz coil driven by pulses with peak voltages from 10-15kV. A fast photodiode (FND-100) with a rise time factor of 1kV/s was used for optical measurements. The fast signals were captured by a 250 Mhz storage digitizing oscilloscope. Results of the investigation show that the constructed model operates at an underdamped discharge mode. The spark gap resistance was measured at ≅ 0.5 Ω. The spark gap inductance was of the order of ≅ 1.7 nH. The peak electrical input power was placed ≅ 50 MW. The peak optical power was measured at 111mW. Finally, the laser pulse full-width was determined at 10 ns. Parametric studies on the nitrogen laser have been done to determine its optimum operating conditions. The nitrogen laser performance is usually obtained by determining the laser channel inductance and resistance. Lg and rg. These values subsequently give the laser channel current discharge and the electrical power absorbed by the laser channel. The determination of the quantities Lg and rg have been the object of many studies, but it is more desirable to have a direct measure of these quantities. This study aims to measure these constants

  1. Characterization of Nitrogen Glow Discharge Plasma via Optical Emission Spectrum Simulation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lianzhu; ZHAO Shuxia; MENG Xiulan

    2008-01-01

    Optical emission spectroscopy in nitrogen glow discharge plasma is simulated, and the collision excitations and characteristic emissions of the species (N2, N2+, N+, N) are investigated by a Monte Carlo model for nitrogen molecular gas discharge. The excitation rates of the main excited states are calculated and the corresponding relation and relative magnitude between the distribution of excitation rate of a certain excited state and the distributions of the emission rates of various lines originating from this excited level are also explored. The simulated results are compared with the experimental measurements in two typical discharge conditions. The luminescence mechanism of the line N2+: 391.4 nm is explained based on the microscopic plasma processes. The cathode glow in N2 discharge is found to be mainly caused by N+impact excitation and the intensity of cathode glow decreases with the voltage. The corresponding relation between the emission rate or intensity of the 391.4 nm line and the production rate and the density of N2+ is also examined.

  2. Regulation of the nitrogen transfer pathway in the arbuscular mycorrhizal symbiosis: gene characterization and the coordination of expression with nitrogen flux.

    Science.gov (United States)

    Tian, Chunjie; Kasiborski, Beth; Koul, Raman; Lammers, Peter J; Bücking, Heike; Shachar-Hill, Yair

    2010-07-01

    The arbuscular mycorrhiza (AM) brings together the roots of over 80% of land plant species and fungi of the phylum Glomeromycota and greatly benefits plants through improved uptake of mineral nutrients. AM fungi can take up both nitrate and ammonium from the soil and transfer nitrogen (N) to host roots in nutritionally substantial quantities. The current model of N handling in the AM symbiosis includes the synthesis of arginine in the extraradical mycelium and the transfer of arginine to the intraradical mycelium, where it is broken down to release N for transfer to the host plant. To understand the mechanisms and regulation of N transfer from the fungus to the plant, 11 fungal genes putatively involved in the pathway were identified from Glomus intraradices, and for six of them the full-length coding sequence was functionally characterized by yeast complementation. Two glutamine synthetase isoforms were found to have different substrate affinities and expression patterns, suggesting different roles in N assimilation. The spatial and temporal expression of plant and fungal N metabolism genes were followed after nitrate was added to the extraradical mycelium under N-limited growth conditions using hairy root cultures. In parallel experiments with (15)N, the levels and labeling of free amino acids were measured to follow transport and metabolism. The gene expression pattern and profiling of metabolites involved in the N pathway support the idea that the rapid uptake, translocation, and transfer of N by the fungus successively trigger metabolic gene expression responses in the extraradical mycelium, intraradical mycelium, and host plant.

  3. Principles and applications of Ligation Mediated PCR methods for DNA-based typing of microbial organisms.

    Science.gov (United States)

    Krawczyk, Beata; Kur, Józef; Stojowska-Swędrzyńska, Karolina; Śpibida, Marta

    2016-01-01

    A significant number of DNA-based techniques has been introduced into the field of microorganisms' characterization and taxonomy. These genomic fingerprinting methods were developed to detect DNA sequence polymorphisms by using general principles, such as restriction endonuclease analysis, molecular hybridization, and PCR amplification. In recent years, some alternative techniques based on ligation of oligonucleotide adapters before DNA amplification by PCR, known as Ligation-Mediated PCR methods (LM PCR), have been successfully applied for the typing of microorganisms below the species level. These molecular methods include: Amplified Fragment Length Polymorphism (AFLP), Amplification of DNA fragments Surrounding Rare Restriction Sites (ADSRRS), PCR Melting Profiles (PCR MP), Ligation Mediated PCR/Shifter (LM PCR/Shifter), Infrequent-Restriction-Site Amplification (IRS PCR), double digestion Ligation Mediated Suppression PCR (ddLMS PCR). These techniques are now applied more and more often because they involve less time, are comparably inexpensive, and require only standard lab equipment. Here, we present a general review of this group of methods showing their possibilities and limitations. We also identify questions and propose solutions which may be helpful in choosing a particular LM PCR method for the achievement of the required goal.

  4. Characterization of nitrogen-fixing bacteria from a temperate saltmarsh lagoon, including isolates that produce ethane from acetylene.

    Science.gov (United States)

    Tibbles, B J; Rawlings, D E

    1994-01-01

    Nitrogen-fixing bacteria were isolated from sediments and water of a saltmarsh lagoon on the west coast of South Africa, and characterized according to factors that regulate nitrogen fixation in the marine environment. The majority of isolates were assigned to the Photobacterium or Vibrio genera on the basis of physiological and biochemical characteristics. One isolate was further assigned to the species Vibrio diazotrophicus. Carbohydrate utilization by each diazotrophic isolate was examined. Abilities of the isolates to utilize a range of mono-, di-, and polysaccharides largely reflected the predicted availability of organic carbon and energy in the lagoon, except that chitin was not utilized. Biochemical tests on the utilization of combined nitrogen showed that one isolate could utilize nitrate, and that this strain was susceptible to full repression of nitrogenase activity by 10mM nitrate. Urease activity was not detected in any of the isolates. In the absence of molybdenum two of the isolates, a Photobacterium spp. and V. diazotrophicus, reduced acetylene to ethylene and ethane, a property frequently associated with the activity of alternative nitrogenases. Addition of 25µM molybdenum inhibited ethane production by V. diazotrophicus, but stimulated ethylene and ethane production by the Photobacterium isolate. Addition of 28µM vanadium did not appear to regulate ethane production by either strain. Assays of nitrogenase activity in sediments from which some isolates were obtained indicated that molybdenum was not limiting nitrogenase activity at naturally-occurring concentrations. Southern hybridizations of the chromosomes of these strains with the anfH and vnfH genes of Azotobacter vinelandii and the nifH gene of Klebsiella pneumoniae indicated the presence of only one nitrogenase in these isolates.

  5. Characterization and activity of visible-light-driven TiO 2 photocatalyst codoped with nitrogen and cerium

    Science.gov (United States)

    Liu, Chao; Tang, Xinhu; Mo, Cehui; Qiang, Zhimin

    2008-04-01

    Nitrogen and cerium codoped TiO 2 photocatalysts were prepared by a modified sol-gel process with doping precursors of cerium nitrate and urea, and characterized by X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC), X-ray photoelectron spectra (XPS) and ultraviolet-visible light diffuse reflectance spectra (UV-vis DRS). Results indicate that anatase TiO 2 is the dominant crystalline type in as-prepared samples, and CeO 2 crystallites appear as the doping ratio of Ce/Ti reaches to 3.0 at%. The TiO 2 starts to transform from amorphous phase to anatase at 987.1 K during calcination, according to the TG-DSC curves. The XPS show that three major metal ions of Ce 3+, Ce 4+, Ti 4+ and one minor metal ion of Ti 3+ coexist on the surface. The codoped TiO 2 exhibits significant absorption within the range of 400-500 nm compared to the non-doped and only nitrogen-doped TiO 2. The enhanced photocatalytic activity of the codoped TiO 2 is demonstrated through degradation of methyl orange under visible light irradiation.

  6. Synthesis, Characterization, and Density Functional Theory Analysis of Uranium and Thorium Complexes Containing Nitrogen-Rich 5-Methyltetrazolate Ligands.

    Science.gov (United States)

    Browne, Kevin P; Maerzke, Katie A; Travia, Nicholas E; Morris, David E; Scott, Brian L; Henson, Neil J; Yang, Ping; Kiplinger, Jaqueline L; Veauthier, Jacqueline M

    2016-05-16

    Two nitrogen-rich, isostructural complexes of uranium and thorium, (C5Me5)2U[η(2)-(N,N')-tetrazolate]2 (7) and (C5Me5)2Th[η(2)-(N,N')-tetrazolate]2 (8), containing 5-methyltetrazolate, have been synthesized and structurally characterized by single-crystal X-ray diffraction, electrochemical methods, UV-visible-near-IR spectroscopy, and variable-temperature (1)H NMR spectroscopy. Density functional theory (DFT) calculations yield favorable free energies of formation (approximately -375 kJ/mol) and optimized structures in good agreement with the experimental crystal structures. Additionally, calculated NMR chemical shifts of 7 and 8 are in good agreement with the variable-temperature (1)H NMR experiments. Time-dependent DFT calculations of both complexes yield UV-visible spectroscopic features that are consistent with experiment and provide assignments of the corresponding electronic transitions. The electronic transitions in the UV-visible spectroscopic region are attributed to C5Me5 ligand-to-metal charge transfer. The low-lying molecular orbitals of the tetrazolate ligands (∼2 eV below the HOMO) do not contribute appreciably to experimentally observed electronic transitions. The combined experimental and theoretical analysis of these new nitrogen-rich uranium and thorium complexes indicates the tetrazolate ligand behaves primarily as a σ-donor.

  7. Synthesis and Characterization of Thiophene-derived Amido Bis-nitrogen Mustard and Its Antimicrobial and Anticancer Activities

    Institute of Scientific and Technical Information of China (English)

    唐一丹; 张景勍; 张少林; 耿蓉霞; 周成合

    2012-01-01

    The thiophene-derived amido bis-nitrogen mustard N2,N2,N5,N5-tetrakis(2-chloroethyl)-3,4-dimethylthio- phene-2,5-dicarboxamide was designed and synthesized via five-step reactions from commercially available 2-chloroacetonitrile. This target compound was confirmed by 1H NMR, 13C NMR, MS, IR spectra and elemental analyses, and its structure was further characterized by X-ray single-crystal analysis. The biological activities for the title compound and some intermediates were evaluated in vitro for their antibacterial, antifungal and cytotoxic activities. The preliminary results showed that the title compound could inhibit efficiently the growth of the tested microorganisms including drug-resistant bacteria MRSA to some extent. Moreover, the target compound was found to be effective against prostatic carcinoma cell line (PC-3), breast carcinoma cell line (MCF-7), colon carcinoma (LoVo) and lung cancer (A549). Especially, it gave selective antitumor efficacy against prostatic carcinoma cell line (PC-3) at a low dose. Keywords nitrogen mustard, thiophene, antibacterial, antifungal, cytotoxicity

  8. Synthesis, Characterization, and Density Functional Theory Analysis of Uranium and Thorium Complexes Containing Nitrogen-Rich 5-Methyltetrazolate Ligands.

    Science.gov (United States)

    Browne, Kevin P; Maerzke, Katie A; Travia, Nicholas E; Morris, David E; Scott, Brian L; Henson, Neil J; Yang, Ping; Kiplinger, Jaqueline L; Veauthier, Jacqueline M

    2016-05-16

    Two nitrogen-rich, isostructural complexes of uranium and thorium, (C5Me5)2U[η(2)-(N,N')-tetrazolate]2 (7) and (C5Me5)2Th[η(2)-(N,N')-tetrazolate]2 (8), containing 5-methyltetrazolate, have been synthesized and structurally characterized by single-crystal X-ray diffraction, electrochemical methods, UV-visible-near-IR spectroscopy, and variable-temperature (1)H NMR spectroscopy. Density functional theory (DFT) calculations yield favorable free energies of formation (approximately -375 kJ/mol) and optimized structures in good agreement with the experimental crystal structures. Additionally, calculated NMR chemical shifts of 7 and 8 are in good agreement with the variable-temperature (1)H NMR experiments. Time-dependent DFT calculations of both complexes yield UV-visible spectroscopic features that are consistent with experiment and provide assignments of the corresponding electronic transitions. The electronic transitions in the UV-visible spectroscopic region are attributed to C5Me5 ligand-to-metal charge transfer. The low-lying molecular orbitals of the tetrazolate ligands (∼2 eV below the HOMO) do not contribute appreciably to experimentally observed electronic transitions. The combined experimental and theoretical analysis of these new nitrogen-rich uranium and thorium complexes indicates the tetrazolate ligand behaves primarily as a σ-donor. PMID:27110650

  9. Nitrogen deficiency system is helpful in characterizing regulation mechanisms of ectopic triacylglycerol accumulation in Arabidopsis seedlings.

    Science.gov (United States)

    Yang, Yang; Yu, Xiangchun; Song, Lianfen; An, Chengcai

    2011-12-01

    Triacylglycerol (TAG) is the major storage component accumulated in seed. However the regulatory mechanism of TAG synthesis and accumulation in non-seed tissues remains unknown. Recently, we found that nitrogen (N) deficiency (0.1mM N) caused an inducement of TAG biosynthesis in Arabidopsis seedlings. ABSCISIC ACID INSENSITIVE 4 (ABI4) was essential for the activation of Acyl-CoA:diacylglycerol acyltransferase1(DGAT1) expression during N deficiency in Arabidopsis seedlings. In this addendum, we further discussed the approaches to provide a net increase in total oil production in higher plants by using the low N platform. First, the N-deficient seedlings can be used to determine the key factors that regulate the ectopic expression of key genes in TAG metabolism. Second, the research on the relationship between TAG homeostasis and cell division will be helpful to find the key factors that specifically regulate TAG accumulation under the nutrient-limited condition. PMID:22112453

  10. Synthesis and characterization of Ni-Mo bimetallic nitride from the mixture of nitrogen and hydrogen

    International Nuclear Information System (INIS)

    A new method for the synthesis of Ni-Mo bimetallic nitrides was reported in the present paper. The bimetallic nitrides were successfully prepared by a temperature-programmed reaction between bimetallic oxide precursors and the mixed gases of N2 and H2 instead of NH3. By adjusting pH values of the solution in the process of co-precipitation, pure NiMoO4 or NiMoO4 with excess MoO3 was obtained, and then pure Ni3Mo3N or Ni3Mo3N with γ-Mo2N was synthesized by nitriding the precursors. The structural properties of the precursors and their corresponding nitrides were investigated by means of X-ray diffraction (XRD), ultraviolet laser Raman spectroscopy, thermogravimetric (TG) analysis and chemical analysis of total nitrogen content

  11. Growth and characterization of BCN nanotubes with high boron and nitrogen content

    Indian Academy of Sciences (India)

    Guo Zhang; Zhiye Liu; Lianping Zhang; Liqiang Jing; Keying Shi

    2013-09-01

    Multiwalled carbon nanotubes doped with boron and nitrogen (BCNTs) have been synthesized by chemical vapour deposition at temperatures ranging from 800°C to 950°C. Their morphological and structural features have been studied by transmission electron microscope, which reveal that BCNTs have bamboo-like structure. The results of X-ray photoelectron spectroscopy demonstrated that the atomic ratio of B, C and N of BCNTs is about 1:4:1, when temperature is 850°C. Electrooxidation performance of the BCNTs for NO at the modified electrodes was investigated. The results of cyclic voltammograms and the electrochemical impedance spectroscopy of BCNT-modified electrodes indicated that the activity of NO electrooxidation on 850°C-modified electrodes is much stronger than others and the charge transfer resistance of NO electroxidation BCNT-modified electrode is the least. By this means, BCNT-modified electrodes showed excellent electrode materials for NO detection and other potential applications.

  12. Platinum incorporation in the Na Y zeolite through impregnation method, and characterization by XRD, FTIR and nitrogen adsorption

    International Nuclear Information System (INIS)

    Supported metal catalysts are widely used in petroleum refining, chemical and petroleum industries. These catalysts are important in ammonia synthesis, conversion of hydrocarbons with water vapor to synthesis gas, reforming, hydrocracking, ... Platinum has long been used in cracking, hydrogenation and dehydrogenation processes. The aim of this project is the Na Y zeolitic sample preparation through impregnation for incipient humidity, with 0,5% concentration of platinum, aiming its use as a catalyst in the steam reforming reaction. The characterization techniques used were: X Rays Diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) and Nitrogen Adsorption (BET Method). From the obtained results through the techniques mentioned previously it is possible to evidence that the platinum impregnation process did not change the Na Y zeolite structure. Through the superficial specific area (BET) it was possible to observe that the platinum impregnation process caused a decrease in the specific area due to the reduction to the accessibility to the micropores of the zeolitic structure. (author)

  13. Tubal ligation and risk of ovarian cancer subtypes

    DEFF Research Database (Denmark)

    Sieh, Weiva; Salvador, Shannon; McGuire, Valerie;

    2013-01-01

    Tubal ligation is a protective factor for ovarian cancer, but it is unknown whether this protection extends to all invasive histological subtypes or borderline tumors. We undertook an international collaborative study to examine the association between tubal ligation and ovarian cancer subtypes....

  14. Ligation bias in illumina next-generation DNA libraries: implications for sequencing ancient genomes.

    Directory of Open Access Journals (Sweden)

    Andaine Seguin-Orlando

    Full Text Available Ancient DNA extracts consist of a mixture of endogenous molecules and contaminant DNA templates, often originating from environmental microbes. These two populations of templates exhibit different chemical characteristics, with the former showing depurination and cytosine deamination by-products, resulting from post-mortem DNA damage. Such chemical modifications can interfere with the molecular tools used for building second-generation DNA libraries, and limit our ability to fully characterize the true complexity of ancient DNA extracts. In this study, we first use fresh DNA extracts to demonstrate that library preparation based on adapter ligation at AT-overhangs are biased against DNA templates starting with thymine residues, contrarily to blunt-end adapter ligation. We observe the same bias on fresh DNA extracts sheared on Bioruptor, Covaris and nebulizers. This contradicts previous reports suggesting that this bias could originate from the methods used for shearing DNA. This also suggests that AT-overhang adapter ligation efficiency is affected in a sequence-dependent manner and results in an uneven representation of different genomic contexts. We then show how this bias could affect the base composition of ancient DNA libraries prepared following AT-overhang ligation, mainly by limiting the ability to ligate DNA templates starting with thymines and therefore deaminated cytosines. This results in particular nucleotide misincorporation damage patterns, deviating from the signature generally expected for authenticating ancient sequence data. Consequently, we show that models adequate for estimating post-mortem DNA damage levels must be robust to the molecular tools used for building ancient DNA libraries.

  15. Ligation bias in illumina next-generation DNA libraries: implications for sequencing ancient genomes.

    Science.gov (United States)

    Seguin-Orlando, Andaine; Schubert, Mikkel; Clary, Joel; Stagegaard, Julia; Alberdi, Maria T; Prado, José Luis; Prieto, Alfredo; Willerslev, Eske; Orlando, Ludovic

    2013-01-01

    Ancient DNA extracts consist of a mixture of endogenous molecules and contaminant DNA templates, often originating from environmental microbes. These two populations of templates exhibit different chemical characteristics, with the former showing depurination and cytosine deamination by-products, resulting from post-mortem DNA damage. Such chemical modifications can interfere with the molecular tools used for building second-generation DNA libraries, and limit our ability to fully characterize the true complexity of ancient DNA extracts. In this study, we first use fresh DNA extracts to demonstrate that library preparation based on adapter ligation at AT-overhangs are biased against DNA templates starting with thymine residues, contrarily to blunt-end adapter ligation. We observe the same bias on fresh DNA extracts sheared on Bioruptor, Covaris and nebulizers. This contradicts previous reports suggesting that this bias could originate from the methods used for shearing DNA. This also suggests that AT-overhang adapter ligation efficiency is affected in a sequence-dependent manner and results in an uneven representation of different genomic contexts. We then show how this bias could affect the base composition of ancient DNA libraries prepared following AT-overhang ligation, mainly by limiting the ability to ligate DNA templates starting with thymines and therefore deaminated cytosines. This results in particular nucleotide misincorporation damage patterns, deviating from the signature generally expected for authenticating ancient sequence data. Consequently, we show that models adequate for estimating post-mortem DNA damage levels must be robust to the molecular tools used for building ancient DNA libraries.

  16. Characterization of second generation biomass under thermal conversion and the fate of nitrogen

    NARCIS (Netherlands)

    Giuntoli, J.

    2010-01-01

    This dissertation deals with the characterization of several biomass materials under thermal conversion conditions using small--scale equipment. The fuels are tested under the conditions of slow and fast heating rate pyrolysis and combustion, with the main goal of investigating the chemistry of fuel

  17. Surface characterization and biocompatibility of titanium alloys implanted with nitrogen by Hardion+ technology.

    Science.gov (United States)

    Gordin, D M; Gloriant, T; Chane-Pane, V; Busardo, D; Mitran, V; Höche, D; Vasilescu, C; Drob, S I; Cimpean, A

    2012-12-01

    In this study, the new Hardion+ micro-implanter technology was used to modify surface properties of biomedical pure titanium (CP-Ti) and Ti-6Al-4V ELI alloy by implantation of nitrogen ions. This process is based on the use of an electron cyclotron resonance ion source to produce a multienergetic ion beam from multicharged ions. After implantation, surface analysis methods revealed the formation of titanium nitride (TiN) on the substrate surfaces. An increase in superficial hardness and a significant reduction of friction coefficient were observed for both materials when compared to non-implanted samples. Better corrosion resistance and a significant decrease in ion release rates were observed for N-implanted biomaterials due to the formation of the protective TiN layer on their surfaces. In vitro tests performed on human fetal osteoblasts indicated that the cytocompatibility of N-implanted CP-Ti and Ti-6Al-4V alloy was enhanced in comparison to that of the corresponding non treated samples. Consequently, Hardion+ implantation technique can provide titanium alloys with better qualities in terms of corrosion resistance, cell proliferation, adhesion and viability.

  18. Characterization and solventless growth of salicylic acid macro-crystals involving a nitrogen gas flow

    Energy Technology Data Exchange (ETDEWEB)

    Menaa, B. [Fluorotronics, Inc., San Diego Technology Incubator, 1425 Russ. Bvld, San Diego, CA 92121 (United States); Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Takahashi, M. [Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Department of Materials science, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan); Tokuda, Y.; Yoko, T. [Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan)

    2010-04-15

    We report an original solventless thermal crystallisation method to grow large needle-like salicylic acid (SA) crystals of 10-12 mm in length. The method is based on the utilization of nitrogen gaz flow on salicylic acid powder during heating just below melting point temperature for 24 h. Salicylic acid provides one of the best examples of a pharmaceutical substance used for cosmetics whose physical and chemical properties indicate hydrogen-bond formation between the hydroxyl group and an adjacent oxygen atom of the same molecule. The structure of the crystals is confirmed by single crystal X-ray diffraction; it is monoclinic, a = 4.93(2) Aa, b = 11.23(5) Aa, c = 11.56(6) Aa, {beta} = 90.77(4) with the space group P 2{sub 1}/c. The macrocrystals formation using this method is new and represents an interesting finding for a wide range of applications to be developed in the fields of biotechnology and photonics (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Biochemical characterization of reactive nitrogen species by eosinophil peroxidase in tyrosine nitration

    Directory of Open Access Journals (Sweden)

    Hitomi,Yoshiaki

    2007-02-01

    Full Text Available It is well known that eosinophils are involved in tyrosine nitration. In this study, we evaluated tyrosine nitration by rat eosinophils isolated from peritoneal fl uid and constituent eosinophils in the stomach. Rat peritoneal eosinophils activated with 1 μM phorbol myristate acetate (PMA and 50 μM NO2 ン showed immunostaining for nitrotyrosine only in smaller cells, despite the fact that eosinophils are capable of producing superoxide (O2·ン. Free tyrosine nitrating capacity after incubation with PMA and NO2 ン was 4-fold higher in eosinophils than in neutrophils. Catalase and ク- and コ -tocopherol inhibited free tyrosine nitration by reactive nitrogen species from eosinophils but not that by peroxynitrite. Superoxide dismutase augmented free tyrosine nitration by activated eosinophils and peroxynitrite. The concentration of nitric oxide released from eosinophils was relatively low (0.32 μM/106 cells/h and did not contribute to the formation of nitrotyrosine. On the other hand, most constituent eosinophils constituent in the rat stomach stimulated by PMA and NO2 ン showed tyrosine nitration capacity. These results suggest that intact cells other than apoptotic-like eosinophils eluted in the intraperitoneal cavity could not generate reactive species responsible for nitration by a peroxidase-dependent mechanism. In contrast, normal eosinophils in the stomach were capable of nitration, suggesting that the characteristics of eosinophils in gastric mucosa are diff erent from those eluted in the peritoneal cavity.

  20. The Diels-Alder-Reaction with inverse-Electron-Demand, a very efficient versatile Click-Reaction Concept for proper Ligation of variable molecular Partners

    OpenAIRE

    Manfred Wiessler, Waldemar Waldeck, Christian Kliem, Ruediger Pipkorn, Klaus Braun

    2010-01-01

    The ligation of active pharmaceutical ingredients (API) for working with image processing systems in diagnostics (MRT) attracts increasing notice and scientific interest. The Diels-Alder ligation Reaction with inverse electron demand (DARinv) turns out to be an appropriate candidate. The DARinv is characterized by a specific distribution of electrons of the diene and the corresponding dienophile counterpart. Whereas the reactants in the classical Diels-Alder Reaction feature electron-rich die...

  1. The Diels-Alder-Reaction with inverse-Electron-Demand, a very efficient versatile Click-Reaction Concept for proper Ligation of variable molecular Partners

    OpenAIRE

    Wiessler, Manfred; Waldeck, Waldemar; Kliem, Christian; Pipkorn, Ruediger; Braun, Klaus

    2009-01-01

    The ligation of active pharmaceutical ingredients (API) for working with image processing systems in diagnostics (MRT) attracts increasing notice and scientific interest. The Diels-Alder ligation Reaction with inverse electron demand (DARinv) turns out to be an appropriate candidate. The DARinv is characterized by a specific distribution of electrons of the diene and the corresponding dienophile counterpart. Whereas the reactants in the classical Diels-Alder Reaction feature electron-rich die...

  2. Assessment of MRI issues at 3-Tesla for metallic surgical implants: findings applied to 61 additional skin closure staples and vessel ligation clips

    OpenAIRE

    Gill Amreeta; Shellock Frank G

    2012-01-01

    Abstract Purpose Metallic skin closure staples and vessel ligation clips should be tested at 3-Tesla to characterize MRI issues in order to ensure patient safety. Therefore, metallic surgical implants were assessed at 3-Tesla for magnetic field interactions, MRI-related heating, and artifacts. Methods A skin closure staple (Visistat Skin Stapler, staple, Polytetrafluoroethylene, PTFE, coated 316L/316LVM stainless steel; Teleflex Medical, Durham, NC) and a vessel ligation clip (Hemoclip Tradit...

  3. Outcome of band ligation in oesophageal varices

    International Nuclear Information System (INIS)

    Objective: To find out the outcome og band ligation of oesophageal varices in decompensated chronic liver disease patients. Methods: The quasi experimental study was conducted at the Jinnah Postgraduate Medical Centre, Karachi, and Civil Hospital, Karachi, unit from September 2007 to August 2011. Subjects were eligible if they had a diagnosis of cirrhosis based on history, physical examination, biochemical parameters and liver biopsy in some cases. Patients with advanced cirrhosis (Child-Pugh class C), antibodies against human immunodeficiency virus, hepatocellular carcinoma, portal vein thrombosis evident on ultrasonography, parenteral drug addiction, current alcohol abuse, previous or current treatment with β-blockers were excluded from the study. All patients were asked about alcohol intake and tested to determine the cause of liver cirrhosis. Tests for other causes of cirrhosis were carried out only if there was a suggestive clue. All patients under-went upper gastrointestinal endoscopy after consent. SPSS 15 was used for statistical analysis. Results: The age of the 173 patients who met the inclusion criteria ranged from 15 to 85 years, with a mean of 48.39+-13.38 years. There were 112 (64.7%) males. High-grade varices were seen in 130 (75.1%) patients, while low-grade varices were observed in 43 (24.9%) on first endoscopy. At initial endoscopy, 111 (64.2%) patients had portal hypertensive gastropathy. The patients were followed up for a mean period of 5.20+-2.67 months. Variceal obliteration was achieved in 138 (79.8%), while 33 (19.1%) cases developed re-bleeding. Mean number of endoscopy sessions for these patients were 2.28+-.918 with a maximum of 4. Conclusion: Band ligation eradicated oesophageal varices with less complications and a lower re-bleeding rate, but at the same time eradication was associated with more frequent development of portal hypertensive gastropathy. (author)

  4. Enabling N-to-C Ser/Thr Ligation for Convergent Protein Synthesis via Combining Chemical Ligation Approaches.

    Science.gov (United States)

    Lee, Chi Lung; Liu, Han; Wong, Clarence T T; Chow, Hoi Yee; Li, Xuechen

    2016-08-24

    In this article, Ser/Thr ligation(on/off) has been realized to enable N-to-C successive peptide ligations using a salicylaldehyde semicarbazone (SAL(off)) group by in situ activation with pyruvic acid of the peptide SAL(off) ester into the peptide salicylaldehyde (SAL(on)) ester. In addition, a peptide with a C-terminal thioester and N-terminal Ser or Thr as the middle peptide segment can undergo one-pot Ser/Thr ligation and native chemical ligation in the N-to-C direction. The utility of this combined ligation strategy in the N-to-C direction has been showcased through the convergent assembly of a human cytokine protein sequence, GlcNAcylated interleukin-25. PMID:27479006

  5. Characterization and quantification of the oxides of sulfur and nitrogen and associated compounds in their gaseous, aerosol, and dissolved states

    Energy Technology Data Exchange (ETDEWEB)

    Newman, L

    1980-05-01

    The needs and problems associated with the characterization and quantification of the oxides of sulfur and nitrogen and associated compounds in their gaseous, aerosol, and dissolved states are discussed. Illustrations are given of the techniques in present usage for the determination of the substances of interest to investigators concerned with the effects of air pollutants on the terrestrial ecosystem. The value and utility of the newer techniques employing real time continuous instrumentation are presented and compared with the more traditional approaches utilizing sampling collection. A plea is made to provide resources for data reduction especially in order to obtain constructive utilization of continuous instrumentation. It is asserted that real time instrumentation is best utilized during campaign measurement programs where short time resolution is required and that collection techniques still have a place, especially in long term monitoring efforts. Special attention was directed at, and the problems highlighted that are associated with, the utilization of the real time instruments available for the flame photometric determination of the oxides of sulfur and the chemiluminescent measurement of the oxides of nitrogen. The newer methods proposed for their use in the determination of sulfate and nitric acid respectively are presented. The difficulties associated with the determination of nitrate are enunciated and attention focused on the problems of obtaining a sample due to the variation of the vapor pressure of gaseous nitric acid and ammonia above solid ammonium nitrate which is in association with an acidic aerosol containing sulfate. The utility of measurements of the composition of rainwater is discussed in light of its application to determine the mechanisms through which rain derives its chemical composition.

  6. Molecular characterization of water soluble organic nitrogen in marine rainwater by ultra-high resolution electrospray ionization mass spectrometry

    Directory of Open Access Journals (Sweden)

    K. E. Altieri

    2011-11-01

    Full Text Available Atmospheric water soluble organic nitrogen (WSON is a subset of the complex organic matter in aerosols and rainwater, which impacts cloud condensation processes and aerosol chemical and optical properties, and may play a significant role in the biogeochemical cycle of N. However, its sources, composition, connections to inorganic N, and variability are largely unknown. Rainwater samples were collected on the island of Bermuda (32.27° N, 64.87° W, which experiences both anthropogenic and marine influenced air masses. Samples were analyzed by ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to chemically characterize the WSON. Elemental compositions of 2455 N containing compounds were determined over the mass range m/z+ 50 to 500. The five compound classes with the largest number of elemental formulas identified, in order from the highest number of formulas to the lowest, contained carbon, hydrogen, oxygen, and nitrogen (CHON+, CHON compounds that contained sulfur (CHONS+, CHON compounds that contained phosphorous (CHONP+, CHON compounds that contained both sulfur and phosphorous (CHONSP+, and compounds that contained only carbon, hydrogen, and nitrogen (CHN+. No organonitrates or nitrooxy-organosulfates were detected, but there was an increased presence of organic S and organic P containing compounds in the marine rainwater. Compared to rainwater collected in the continental USA, average O:C ratios of all N containing compound classes were lower in the marine samples whereas double bond equivalent values were higher, suggesting a reduced role of secondary formation mechanisms. Cluster analysis showed a clear chemical distinction between samples collected during the cold season (October to March which have anthropogenic air mass origins and samples collected during the warm season (April to September with remote marine air mass origins. This, in conjunction with patterns

  7. Molecular characterization of water soluble organic nitrogen in marine rainwater by ultra-high resolution electrospray ionization mass spectrometry

    Science.gov (United States)

    Altieri, K. E.; Hastings, M. G.; Peters, A. J.; Sigman, D. M.

    2012-04-01

    Atmospheric water soluble organic nitrogen (WSON) is a subset of the complex organic matter in aerosols and rainwater, which impacts cloud condensation processes and aerosol chemical and optical properties and may play a significant role in the biogeochemical cycle of N. However, its sources, composition, connections to inorganic N, and variability are largely unknown. Rainwater samples were collected on the island of Bermuda (32.27° N, 64.87° W), which experiences both anthropogenic and marine influenced air masses. Samples were analyzed by ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to chemically characterize the WSON. Elemental compositions of 2281 N containing compounds were determined over the mass range m/z+ 50 to 500. The five compound classes with the largest number of elemental formulas identified, in order from the highest number of formulas to the lowest, contained carbon, hydrogen, oxygen, and nitrogen (CHON+), CHON compounds that contained sulfur (CHONS+), CHON compounds that contained phosphorus (CHONP+), CHON compounds that contained both sulfur and phosphorus (CHONSP+), and compounds that contained only carbon, hydrogen, and nitrogen (CHN+). Compared to rainwater collected in the continental USA, average O:C ratios of all N containing compound classes were lower in the marine samples whereas double bond equivalent values were higher, suggesting a reduced role of secondary formation mechanisms. Despite their prevalence in continental rainwater, no organonitrates or nitrooxy-organosulfates were detected, but there was an increased presence of organic S and organic P containing compounds in the marine rainwater. Cluster analysis showed a clear chemical distinction between samples collected during the cold season (October to March) which have anthropogenic air mass origins and samples collected during the warm season (April to September) with remote marine air mass origins. This, in

  8. Evaluation of a soil incubation method to characterize nitrogen release patterns of slow- and controlled-release fertilizers.

    Science.gov (United States)

    Medina, L Carolina; Sartain, Jerry B; Obreza, Thomas A; Hall, William L; Thiex, Nancy J

    2014-01-01

    Several technologies have been proposed to characterize the nutrient release patterns of slow-release fertilizers (SRF) and controlled-release fertilizers (CRF) during the last few decades. These technologies have been developed mainly by manufacturers, and are product-specific, based on the regulation and analysis of each SRF and CRF product. Despite previous efforts to characterize SRF and CRF materials, no standardized, validated method exists to assess their nutrient release patterns. However, the increased production and distribution of these materials in specialty and nonspecialty markets requires an appropriate method to verify product claims and material performance. A soil incubation column leaching procedure was evaluated to determine its suitability as a standard method to estimate nitrogen (N) release patterns of SRFs and CRFs during 180 days. The influence of three soil/sand ratios, three incubation temperatures, and four soils on method behavior was assessed using five SRFs and three CRFs. In general, the highest soil/sand ratio increased the N release rate of all materials, but this effect was more marked for the SRFs. Temperature had the greatest influence on N release rates. For CRFs, the initial N release rates and the percentage N released/day increased as temperature increased. For SRFs, raising the temperature from 25 to 35 degreesC increased initial N release rate and the total cumulative N released, and almost doubled the percentage released/day. The percentage N released/day from all products generally increased as the texture of the soil changed from sandy to loamy (lowa>California>Pennsylvania>Florida). The soil incubation technique was demonstrated to be robust and reliable for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and variations in soil/sand ratio, temperature, and soil had little effect on the results. PMID:25051610

  9. Convergent synthesis of proteins by kinetically controlled ligation

    Science.gov (United States)

    Kent, Stephen; Pentelute, Brad; Bang, Duhee; Johnson, Erik; Durek, Thomas

    2010-03-09

    The present invention concerns methods and compositions for synthesizing a polypeptide using kinetically controlled reactions involving fragments of the polypeptide for a fully convergent process. In more specific embodiments, a ligation involves reacting a first peptide having a protected cysteyl group at its N-terminal and a phenylthioester at its C-terminal with a second peptide having a cysteine residue at its N-termini and a thioester at its C-termini to form a ligation product. Subsequent reactions may involve deprotecting the cysteyl group of the resulting ligation product and/or converting the thioester into a thiophenylester.

  10. Extended X-ray absorption fine structure studies of Zn2Fe2 hybrid hemoglobins: absence of heme bond length changes in half-ligated species.

    Science.gov (United States)

    Simolo, K; Korszun, Z R; Stucky, G; Moffat, K; McLendon, G; Bunker, G

    1986-07-01

    Metal hybrid hemoglobins, in which Zn(II) replaces Fe(II), have been structurally characterized by extended X-ray absorption structure (EXAFS) studies. Since Zn and Fe have very different K absorption edge energies, the structures of the ligated (Fe) and unligated (Zn) sites could be examined independently within a single molecule that mimics an intermediate ligation state. The observed EXAFS spectra and associated structural parameters are compared among the ligand free (alpha Zn)2(beta Zn)2, half-ligated (alpha FeCO)2(beta Zn)2 and (alpha Zn)2(beta FeCO)2, and fully ligated (alpha FeCO)2(beta FeCO)2 systems.

  11. Fractionation and characterization of polysaccharides from cyanobacterium Spirulina (Arthrospira) maxima in nitrogen-limited batch culture

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By a sequentially selective extraction procedure, polysaccharides (PS) from cyanobacterium Spirulina (Arthrospira) maxima that can be bio-functionally healthy components were fractionated in four parts including the culture medium (PSCM), the external layers of the cell (PSEL), the cell wall (PSCW) and storage granules (PSSG). The four fractionated parts of polysaccharides were characterized by gas-liquid chromatography (GLC) equipped with FID and fused-silica capillary column (15 m×0.53 mm i. d.). The contents of PSCM, PSEL, PSCW and PSSG were about 2.0%, 2.6%, 10.0% and 52.0% to cell dry matter, respectively. Glucose was almost the only monosaccharide in PSSG and PSCW and most predominant in PSEL, while in PSCM, xylose, rhamnose and glucose were the main ones. Two uronic acids represented by glucuronic acid and galacturoic acid, six neutral monosaccharides including fucose, rhamnose, xylose, mannose, galactose and glucose, and two possible unidentified sugars were found in PSEL and PSCM. These data are valuable for the selective productions of high-added value sugars from Spirulina.

  12. Theoretical characterization of X-ray absorption, emission, and photoelectron spectra of nitrogen doped along graphene edges.

    Science.gov (United States)

    Wang, Xianlong; Hou, Zhufeng; Ikeda, Takashi; Oshima, Masaharu; Kakimoto, Masa-aki; Terakura, Kiyoyuki

    2013-01-24

    K-edge X-ray absorption (XAS), emission (XES), and photoelectron (XPS) spectra of nitrogen doped along graphene edges are systematically investigated by using first-principles methods. In this study we considered pyridinium-like, pyridine-like, cyanide-like, and amine-like nitrogens at armchair and zigzag edges and pyrrole-like nitrogen at armchair edge as well as graphite-like nitrogen at graphene interior site. Our results indicate that nitrogen configuration and its location (armchair or zigzag edge) in nitrogen-doped graphene can be identified via the spectral analysis. Furthermore, some controversial spectral features observed in experiment for N-doped graphene-like materials are unambiguously assigned. The present analysis gives an explanation to the reason why the peak assignment is usually made differently between XPS and XAS.

  13. Enhanced nitrogen removal in a wastewater treatment process characterized by carbon source manipulation with biological adsorption and sludge hydrolysis.

    Science.gov (United States)

    Liu, Hongbo; Zhao, Fang; Mao, Boyang; Wen, Xianghua

    2012-06-01

    An innovative adsorption/nitrification/denitrification/sludge-hydrolysis wastewater treatment process (ENRS) characterized by carbon source manipulation with a biological adsorption unit and a sludge hydrolysis unit was developed to enhance nitrogen removal and reduce sludge production for municipal wastewater treatment. The system presented good performance in pollutants removal, yielding the effluent with average COD, NH(4)(+)-N, TN and TP of 48.5, 0.6, 13.2 and 1.0 mg/L, respectively. Sixty percent of the total carbon source in the influent was concentrated and separated by the quick adsorption of activated sludge, providing the possibilities of reusing waste carbon source in the denitrification tank and accumulating nitrobacteria in the nitrification tank. Low temperature of 6-15 °C and high hydraulic loading rate of 3.0-15.0 m(3)/d did not affect NH(4)(+)-N removal performance, yielding the NH(4)(+)-N of lower 1.0 mg/L in the effluent. Furthermore, 50% of the residual sludge in the ENRS system could be transformed into soluble COD (SCOD) by alkaline thermal hydrolysis with temperature of 60 °C and pH of 11, and the hydrolyzed carbon could completely substitute methanol as a good quality carbon to support high efficient denitrification.

  14. Formatting and ligating biopolymers using adjustable nanoconfinement

    Science.gov (United States)

    Berard, Daniel J.; Shayegan, Marjan; Michaud, Francois; Henkin, Gil; Scott, Shane; Leslie, Sabrina

    2016-07-01

    Sensitive visualization and conformational control of long, delicate biopolymers present critical challenges to emerging biotechnologies and biophysical studies. Next-generation nanofluidic manipulation platforms strive to maintain the structural integrity of genomic DNA prior to analysis but can face challenges in device clogging, molecular breakage, and single-label detection. We address these challenges by integrating the Convex Lens-induced Confinement (CLiC) technique with a suite of nanotopographies embedded within thin-glass nanofluidic chambers. We gently load DNA polymers into open-face nanogrooves in linear, concentric circular, and ring array formats and perform imaging with single-fluorophore sensitivity. We use ring-shaped nanogrooves to access and visualize confinement-enhanced self-ligation of long DNA polymers. We use concentric circular nanogrooves to enable hour-long observations of polymers at constant confinement in a geometry which eliminates the confinement gradient which causes drift and can alter molecular conformations and interactions. Taken together, this work opens doors to myriad biophysical studies and biotechnologies which operate on the nanoscale.

  15. Periodontal effects with self ligating appliances and laser biostimulation

    Directory of Open Access Journals (Sweden)

    Gianluigi Caccianiga

    2012-01-01

    Conclusions: The combination between self ligating appliances and laser′s biostimulation could improve the differentiation of periodontal ligaments stem cells in fibroblasts, able to promote attached gingiva around the crown of the teeth erupted in oral vestibular mucosa.

  16. A Photo-Triggered Traceless Staudinger-Bertozzi Ligation Reaction.

    Science.gov (United States)

    Hu, Peng; Feng, Tianshi; Yeung, Chi-Chung; Koo, Chi-Kin; Lau, Kai-Chung; Lam, Michael H W

    2016-08-01

    The use of light to control the course of a chemical/biochemical reaction is an attractive idea because of its ease of administration with high precision and fine spatial resolution. Staudinger ligation is one of the commonly adopted conjugation processes that involve a spontaneous reaction between azides and arylphosphines to form iminophosphoranes, which further hydrolyze to give stable amides. We designed an anthracenylmethyl diphenylphosphinothioester (1) that showed promising Staudinger ligation reactivity upon photo-excitation. Broadband photolysis at 360-400 nm in aqueous organic solvents induced heterolytic cleavage of its anthracenylmethyl-phosphorus bond, releasing a diphenylphosphinothioester (2) as an efficient traceless Staudinger-Bertozzi ligation reagent. The quantum yield of such a photo-induced heterolytic bond-cleavage at the optimal wavelength of photolysis (376 nm) at room temperature is ≥0.07. This work demonstrated the feasibility of photocaging arylphosphines to realize the photo-triggering of the Staudinger ligation reaction. PMID:27123884

  17. A Photo-Triggered Traceless Staudinger-Bertozzi Ligation Reaction.

    Science.gov (United States)

    Hu, Peng; Feng, Tianshi; Yeung, Chi-Chung; Koo, Chi-Kin; Lau, Kai-Chung; Lam, Michael H W

    2016-08-01

    The use of light to control the course of a chemical/biochemical reaction is an attractive idea because of its ease of administration with high precision and fine spatial resolution. Staudinger ligation is one of the commonly adopted conjugation processes that involve a spontaneous reaction between azides and arylphosphines to form iminophosphoranes, which further hydrolyze to give stable amides. We designed an anthracenylmethyl diphenylphosphinothioester (1) that showed promising Staudinger ligation reactivity upon photo-excitation. Broadband photolysis at 360-400 nm in aqueous organic solvents induced heterolytic cleavage of its anthracenylmethyl-phosphorus bond, releasing a diphenylphosphinothioester (2) as an efficient traceless Staudinger-Bertozzi ligation reagent. The quantum yield of such a photo-induced heterolytic bond-cleavage at the optimal wavelength of photolysis (376 nm) at room temperature is ≥0.07. This work demonstrated the feasibility of photocaging arylphosphines to realize the photo-triggering of the Staudinger ligation reaction.

  18. PUNICA GRANATUM ATTENUATES SCIATIC NERVE LIGATION INDUCED-NEUROPATHIC PAIN

    OpenAIRE

    Ramica Sharma et al.

    2012-01-01

    The study has been designed to investigate the effect of aqueous extract of rind of Punica granatum in sciatic nerve ligation induced-neuropathic pain in rats. Surgical procedure was performed with sciatic nerve ligation to develop neuropathic pain in rats. The development of neuropathic pain was assessed by employing behaviour parameters such as hyperalgesia and allodynia. Further, the functionality of sciatic nerve was assessed using the histopathological study of myelinated and unmyelinate...

  19. Synthesis, characterization and antimicrobial activities of mixed ligand transition metal complexes with isatin monohydrazone Schiff base ligands and heterocyclic nitrogen base

    Science.gov (United States)

    Devi, Jai; Batra, Nisha

    2015-01-01

    Mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with various uninegative tridentate ligands derived from isatin monohydrazone with 2-hydroxynapthaldehyde/substituted salicylaldehyde and heterocyclic nitrogen base 8-hydroxyquinoline have been synthesized and characterized by elemental analysis, conductometric studies, magnetic susceptibility and spectroscopic techniques (IR, UV-VIS, NMR, mass and ESR). On the basis of these characterizations, it was revealed that Schiff base ligands existed as monobasic tridentate ONO bonded to metal ion through oxygen of carbonyl group, azomethine nitrogen and deprotonated hydroxyl oxygen and heterocyclic nitrogen base 8-hydroxyquinoline existed as monobasic bidentate ON bonded through oxygen of hydroxyl group and nitrogen of quinoline ring with octahedral or distorted octahedral geometry around metal ion. All the compounds have been tested in vitro against various pathogenic Gram positive bacteria, Gram negative bacteria and fungi using different concentrations (25, 50, 100, 200 μg/mL) of ligands and their complexes. Comparative study of antimicrobial activity of ligands, and their mixed complexes indicated that complexes exhibit enhanced activity as compared to free ligands and copper(II) Cu(LIV)(Q)ṡH2O complex was found to be most potent antimicrobial agent.

  20. Mechanism of Imidazole-Promoted Ligation of Peptide Phenyl Esters

    Institute of Scientific and Technical Information of China (English)

    王晨; 刘磊

    2012-01-01

    Imidazole-promoted ligation of peptide phenyl esters was recently found to be a complementary method for protein chemical synthesis. Theoretical calculations have been carried out to understand the detailed mechanism of this particular ligation process. It is found that both the reaction of the phenyl ester with imidazole and the reaction of the acyl imidazole intermediate with cysteine proceed through an addition-elimination mechanism. The cleavage of the C--O bond in the reaction between the phenyl ester and imidazole is the rate-limiting step of the overall liga- tion process. Interestingly, although the imidazole-promoted phenyl ester ligation has a higher free energy barrier than the conventional thiophenol-promoted native chemical ligation for a sterically less hindered C-terminal amino acid (e.g. gylcine), for a sterically hindered C-terminal amino acid (e.g. proline) the imidazole-promoted phenyl ester ligation is calculated to be more favorable than the conventional thiophenol-promoted native chemical ligation.

  1. Intramyocardial activation in early ventricular arrhythmias following coronary artery ligation.

    Science.gov (United States)

    Kaplinsky, E; Ogawa, S; Kmetzo, J; Balke, C W; Dreifus, L S

    1980-01-01

    Subendocardial, subepicardial and intramyocardial activation in the ischemic zone was investigated in 20 anesthetized open chest dogs 0-30 minutes after the ligation of the left anterior descending coronary artery. Single and composite electrograms and lead 2 of the ECG were recorded. Coronary artery ligation produced marked delay, fragmentation, and reduction in amplitude in the electrical activity of the subepicardial and intramyocardial muscle layers. The activation remained synchronous in the subendocardial muscle layers. Extension of electrical activity in the ischemic subepicardium and intramyocardium beyond the T wave of the surface ECG preceded the onset of immediate ventricular arrhythmias (IVA) during the initial ten minute period after coronary artery ligation. However, a second surge of delayed ventricular arrhythmias (DVA), 10-30 minutes after ligation, was not associated with the appearance of diastolic electrical activity in any of the subepicardial or myocardial layers. It appears that subepicardial as well as intramyocardial reentry could play an important role in the genesis of the immediate ventricular arrhythmias (1-10 minutes after ligation). In contrast, no obvious reentrant activity as evidenced by delayed and fragmented electrical activity could be observed in the electrogram from any of the myocardial electrical activity could be observed in the electrogram from any of the myocardial layers with the appearance of delayed ventricular ectopic activity 10-30 minutes after ligation.

  2. Lipid Raft is required for PSGL-1 ligation induced HL-60 cell adhesion on ICAM-1.

    Directory of Open Access Journals (Sweden)

    Tingshuang Xu

    Full Text Available P-selectin glycoprotein ligand-1 (PSGL-1 and integrins are adhesion molecules that play critical roles in host defense and innate immunity. PSGL-1 mediates leukocyte rolling and primes leukocytes for integrin-mediated adhesion. However, the mechanism that PSGL-1 as a rolling receptor in regulating integrin activation has not been well characterized. Here, we investigate the function of lipid raft in regulating PSGL-1 induced β2 integrin-mediated HL-60 cells adhesion. PSGL-1 ligation with antibody enhances the β2 integrin activation and β2 integrin-dependent adhesion to ICAM-1. Importantly, with the treatment of methyl-β-cyclodextrin (MβCD, we confirm the role of lipid raft in regulating the activation of β2 integrin. Furthermore, we find that the protein level of PSGL-1 decreased in raft fractions in MβCD treated cells. PSGL-1 ligation induces the recruitment of spleen tyrosine kinase (Syk, a tyrosine kinase and Vav1 (the pivotal downstream effector of Syk signaling pathway involved in cytoskeleton regulation to lipid raft. Inhibition of Syk activity with pharmacologic inhibitor strongly reduces HL-60 cells adhesion, implicating Syk is crucial for PSGL-1 mediated β2 integrin activation. Taken together, we report that ligation of PSGL-1 on HL-60 cells activates β2 integrin, for which lipid raft integrity and Syk activation are responsible. These findings have shed new light on the mechanisms that connect leukocyte initial rolling with subsequent adhesion.

  3. A functional model for the cysteinate-ligated non-heme iron enzyme superoxide reductase (SOR).

    Science.gov (United States)

    Kitagawa, Terutaka; Dey, Abhishek; Lugo-Mas, Priscilla; Benedict, Jason B; Kaminsky, Werner; Solomon, Edward; Kovacs, Julie A

    2006-11-15

    Superoxide reductases (SORs) are cysteine-ligated, non-heme iron enzymes that reduce toxic superoxide radicals (O2-). The functional role of the trans cysteinate, as well as the mechanism by which SOR reduces O2-, is unknown. Herein is described a rare example of a functional metalloenzyme analogue, which catalytically reduces superoxide in a proton-dependent mechanism, via a trans thiolate-ligated iron-peroxo intermediate, the first example of its type. Acetic-acid-promoted H2O2 release, followed by Cp2Co reduction, regenerates the active Fe(II) catalyst. The thiolate ligand and its trans positioning relative to the substrate are shown to contribute significantly to the catalyst's function, by lowering the redox potential, changing the spin state, and dramatically lowering the nuFe-O stretching frequency well-below that of any other reported iron-peroxo, while leaving nuO-O high, so as to favor superoxide reduction and Fe-O, as opposed to O-O, bond cleavage. Thus we provide critical insight into the relationship between the SOR structure and its function, as well as important benchmark parameters for characterizing highly unstable thiolate-ligated iron-peroxo intermediates. PMID:17090014

  4. Downregulation of AQP2 and AQP2 mRNA expression in kidney medulla of rats with bile duct ligation

    Institute of Scientific and Technical Information of China (English)

    Yong Wang; Jin-Gang Liu; Ji-Long Han

    2007-01-01

    BACKGROUND:Obstructive jaundice is a common disease. Acute renal injury, secondary to obstructive jaundice, is one of the main causes of postoperative multiple system failure. This investigation evaluated renal function and renal aquaporin 2 (AQP2) expression changes in obstructive jaundice. METHODS:Forty male Wistar rats were equally randomized into two groups. Twenty in the obstructive jaundice group were subjected to common bile duct ligation, and then were subdivided into 7- and 14-day obstruction groups, and the other 20 sham-operated rats were also subdivided into 7- and 14-day groups. At the end of each experiment, rats were sacriifced, venous blood was collected from the inferior vena cava, and serum creatinine and urine nitrogen concentrations were measured. At the same time, the medulla of the right kidney was separated and AQP2 expression was assessed. The RT-PCR technique was used to detect AQP2 mRNA expression. RESULTS:Ligation of the common bile duct caused signiifcant rises in serum bilirubin, creatinine clearance and urine nitrogen. AQP2 expression in the medulla decreased mere signiifcantly (38.35±2.08) in the 7-day ligation group than in the sham-operated group (41.06± 1.04), as did that in the 14-day ligation group, even more than (31.89±1.57). The expression of AQP2 mRNA also decreased more signiifcantly in the 14-day group (0.5429± 0.1107) than in the 7-day group (0.6071±0.1328).CONCLUSION:AQP2 expression is inhibited in obstructive jaundice, and so is its gene expression.

  5. Ligation-free ribosome profiling of cell type-specific translation in the brain

    OpenAIRE

    Hornstein, Nicholas; Torres, Daniela; Das Sharma, Sohani; Tang, Guomei; Canoll, Peter; Sims, Peter A

    2016-01-01

    Ribosome profiling has emerged as a powerful tool for genome-wide measurements of translation, but library construction requires multiple ligation steps and remains cumbersome relative to more conventional deep-sequencing experiments. We report a new, ligation-free approach to ribosome profiling that does not require ligation. Library construction for ligation-free ribosome profiling can be completed in one day with as little as 1 ng of purified RNA footprints. We apply ligation-free ribosome...

  6. Synthesis and Characterization of 4-Benzyloxybenzaldehyde-4-methyl-3-thiosemicarbazone (Containing Sulphur and Nitrogen Donor Atoms) and Its Cd(II) Complex

    OpenAIRE

    Lakshmi Narayana Suvarapu; Sung-Ok Baek

    2015-01-01

    A chelating agent, 4-benzyloxybenzaldehyde-4-methyl-3-thiosemicarbazone (BBMTSC), containing sulphur and nitrogen donor atoms was synthesized and applied as a ligand for the chelation of Cd(II). Both the BBMTSC and its Cd(II) complex were characterized by elemental analysis, UV-Vis absorption spectra, Fourier transform infrared spectroscopy (FT-IR), mass spectra, nuclear magnetic resonance spectroscopy (NMR), X-ray powder diffraction (XRD), and field emission scanning electron microscopy (FES...

  7. PHYSIOLOGICAL MENSTRUAL RHYTHM AND FERTILITY AFTER INTERNAL ILIAC ARTERY LIGATION

    Directory of Open Access Journals (Sweden)

    Sunaina

    2015-11-01

    Full Text Available AIMS AND OBJECTIVE Bilateral internal iliac artery ligation is a useful skill for the management of life-threatening post-partum hemorrhage. The procedure is not without risks and long-term complications. This study was conducted to ensure documentation and reporting of pregnancies following bilateral hypogastric artery ligation in cases of post-partum hemorrhage. We also aimed to compare the menstrual function and reproductive outcome after bilateral internal iliac artery ligation done for atonic post-partum haemorrhage. DESIGN Prospective Case Study. SETTING Department of Obstetrics and Gynaecology, Institute of Obstetrics and Gynaecology, Madras Medical College and Hospital, Chennai, Jan 2013 to March 2015. PARTICIPANTS Ten cases of bilateral internal iliac artery ligation were done for atonic post-partum hemorrhage. Main outcome measures: The primary outcome was assessed as the resumption of menstruation, regular cycles, and ability to conceive after surgery. Secondary outcome was incidence of intrauterine growth retardation and recurrent post-partum hemorrhage in subsequent pregnancies. RESULTS The mean duration of resumption of menstruation following internal iliac artery ligation was 3 months. Bilateral internal iliac artery ligation is preferred over unilateral ligation as the extensive collaterals from the contralateral side immediately fill the circulation. The cases of atonic post-partum hemorrhage may require B-Lynch sutures in addition to bilateral internal iliac artery ligation to regain tone. Successful pregnancy after bilateral internal iliac artery ligation occurred in three out of seven cases. In one case, there was intrauterine growth retardation in eighth month. The patient was admitted and closely monitored with Doppler scan. At 35 weeks of gestation, emergency lower segment caesarean section was done for absent diastolic flow. The preterm neonate was 2 kilograms. There was no post-partum hemorrhage in the subsequent

  8. Characterization of two naturally truncated, Ssb-like proteins from the nitrogen-fixing cyanobacterium, Anabaena sp. PCC7120.

    Science.gov (United States)

    Kirti, Anurag; Rajaram, Hema; Apte, Shree Kumar

    2013-11-01

    Single-stranded (ss) DNA-binding (Ssb) proteins are vital for all DNA metabolic processes and are characterized by an N-terminal OB-fold followed by P/G-rich spacer region and a C-terminal tail. In the genome of the heterocystous, nitrogen-fixing cyanobacterium, Anabaena sp. strain PCC 7120, two genes alr0088 and alr7579 are annotated as ssb, but the corresponding proteins have only the N-terminal OB-fold and no P/G-rich region or acidic tail, thereby rendering them unable to interact with genome maintenance proteins. Both the proteins were expressed under normal growth conditions in Anabaena PCC7120 and regulated differentially under abiotic stresses which induce DNA damage, indicating that these are functional genes. Constitutive overexpression of Alr0088 in Anabaena enhanced the tolerance to DNA-damaging stresses which caused formation of DNA adducts such as UV and MitomycinC, but significantly decreased the tolerance to γ-irradiation, which causes single- and double-stranded DNA breaks. On the other hand, overexpression of Alr7579 had no significant effect on normal growth or stress tolerance of Anabaena. Thus, of the two truncated Ssb-like proteins, Alr0088 may be involved in protection of ssDNA from damage, but due to the absence of acidic tail, it may not aid in repair of damaged DNA. These two proteins are present across cyanobacterial genera and unique to them. These initial studies pave the way to the understanding of DNA repair in cyanobacteria, which is not very well documented.

  9. Clinical application of a ligation-independent pathway of multiplex ligation-dependent probe amplification for the determination of quinolone susceptibility of Streptococcus pneumoniae.

    Science.gov (United States)

    Uno, Naoki; Araki, Nobuko; Kaku, Norihito; Kosai, Kosuke; Hasegawa, Hiroo; Yanagihara, Katsunori

    2016-09-01

    We previously uncovered a ligation-independent pathway of multiplex ligation-dependent probe amplification (MLPA) through which products of MLPA could be amplified without both hybridization and ligation reactions. Here, we utilized this pathway to detect an antibiotic resistance mutation of quinolones in Streptococcus pneumoniae. PMID:27343683

  10. Characterization of thin Ta-Si-N {sub x} layers of different nitrogen content using XPS, UPS and STM

    Energy Technology Data Exchange (ETDEWEB)

    Zahn, W. [University of Applied Science Zwickau, Dr.-Friedrichs-Ring 2A, D-08056 Zwickau (Germany)]. E-mail: wieland.zahn@fh-zwickau.de; Hildebrand, D. [University of Applied Science Zwickau, Dr.-Friedrichs-Ring 2A, D-08056 Zwickau (Germany); Menzel, S. [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Oswald, S. [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Heuer, H. [Dresden University of Technology, D-01062 Dresden (Germany)

    2005-09-30

    Reactively sputtered Ta-Si-N {sub x} barrier systems of different nitrogen content on copper were investigated by photoelectron spectroscopy (XPS, UPS) and scanning tunnelling microscopy (STM). The measured photoelectron spectra (excitation He-I) showed a clear dependence of the electron state density near the Fermi edge on the content of nitrogen. These results correlate with the I(U) characteristics of the STM measurements and the electrical conductivity of these layers.

  11. A Generic Polymer-Protein Ligation Strategy for Vaccine Delivery.

    Science.gov (United States)

    Lybaert, Lien; Vanparijs, Nane; Fierens, Kaat; Schuijs, Martijn; Nuhn, Lutz; Lambrecht, Bart N; De Geest, Bruno G

    2016-03-14

    Although the field of cancer immunotherapy is intensively investigated, there is still a need for generic strategies that allow easy, mild and efficient formulation of vaccine antigens. Here we report on a generic polymer-protein ligation strategy to formulate protein antigens into reversible polymeric conjugates for enhanced uptake by dendritic cells and presentation to CD8 T-cells. A N-hydroxypropylmethacrylamide (HPMA)-based copolymer was synthesized via RAFT polymerization followed by introduction of pyridyldisulfide moieties. To enhance ligation efficiency to ovalbumin, which is used as a model protein antigen, protected thiols were introduced onto lysine residues and deprotected in situ in the presence of the polymer. The ligation efficiency was compared for both the thiol-modified versus unmodified ovalbumin, and the reversibility was confirmed. Furthermore, the obtained nanoconjugates were tested in vitro for their interaction and association with dendritic cells, showing enhanced cellular uptake and antigen cross-presentation to CD8 T-cells.

  12. Development of an Improved Animal Model of Overactive Bladder: Transperineal Ligation versus Transperitoneal Ligation in Male Rats

    Science.gov (United States)

    Kim, Woo Hyun; Bae, Woong Jin; Park, Jung Woo; Choi, Jin Bong; Kim, Su Jin; Cho, Hyuk Jin; Ha, U Syn; Hong, Sung Hoo; Lee, Ji Youl; Hwang, Sung Yeoun

    2016-01-01

    Purpose We compared a transperineal ligation model and a transperitoneal ligation model in male rats to determine which animal model of overactive bladder (OAB) was more useful based on cystometrography, estimations of oxidative stress, and measurements of pro-inflammatory cytokine levels. Materials and Methods Male rats were randomly divided into three groups (n=15 in each): the control group, the transperineal ligation group, and the transperitoneal ligation group. Four weeks after the ligation procedure, cystometrography was performed and oxidative stress, pro-inflammatory cytokine levels, and histologic changes were evaluated. Oxidative stress was assessed by measuring 8-hydroxy-20-deoxyguanosine and superoxide dismutase, and pro-inflammatory cytokine activity was investigated by measuring levels of interleukin (IL)-6, IL-8, and tumor necrosis factor-α. Results The transperineal model led to results similar to those observed for the transperitoneal model, namely (1) increased voiding frequency and reductions in the non-voiding contraction interval and the maximal vesical pressure, (2) increased levels of oxidative stress markers, (3) increased pro-inflammatory cytokine levels, and (4) fibrotic changes in the bladder tissue. Conclusions We suggest that the transperineal procedure can be used as an alternative OAB model in male rats. PMID:27574597

  13. A study of parameter setting and characterization of visible-light driven nitrogen-modified commercial TiO{sub 2} photocatalysts

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Yu-Lin, E-mail: ylkuo@mail.ntust.edu.tw [Department of Mechanical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan (China); Su, Te-Li [Department of Cosmetic Application and Management, St. Mary' s Medicine, Nursing and Management College, Yilan 266, Taiwan (China); Kung, Fu-Chen [Department of Health Developing and Health Marketing, Kainan University, Taoyuan County 338, Taiwan (China); Wu, Tsai-Jung [Department of Mechanical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei 106, Taiwan (China)

    2011-06-15

    Highlights: {yields} A cost-effective and highly-efficient visible-light driven nitrogen-modified TiO{sub 2} photocatalyst was prepared by a simple hydrolysis method. {yields} The obtained optimum conditions applied to Taguchi method for preparing visible-light driven photocatalyst were undergone by the process of stirring for 1 day using 4M ammonium as the nitrogen source, and then calcining at 400{sup Degree-Sign }C for 2 h. {yields} Several materials technologies of characterizing N-TiO2 photocatalyst have been used to realize the modification of TiO2 by ammonia water as the nitrogen source. - Abstract: An optimal condition applied to the Taguchi method with an L{sub 9} orthogonal array for preparing a visible-light driven nitrogen-modified TiO{sub 2} (N-TiO{sub 2}) photocatalyst by a simple hydrolysis method has been examined for material characteristics and a photodecolorization test of methyl blue (MB) under various visible light source (fluorescent and blue LED lamps) irradiations. Results of the material characterization showed that the absorption of prepared N-TiO{sub 2} powder exhibited a significant extension into visible light regimes with an optical bandgap (Eg) of around 2.96 eV, which subsequently improved the visible-light photocatalytic activity of N-TiO{sub 2} samples. The superior photocatalytic properties, the pseudo first-order reaction rate constants (k) and photodecolorization efficiency ({eta}%) of a N-TiO{sub 2} photocatalyst during the photodecolorization test of methyl blue (MB) under two different visible light irradiations were very evident compared to those for pure TiO{sub 2}. For photodecolorization of practical dyeing from the waste water from the dyeing and finishing industry, a higher photodecolorization efficiency of N-TiO{sub 2} powder toward Direct blue-86 (DB-86) (Direct Fast Turquoise Blue GL) dye was also achieved.

  14. Laparoscopic ligation of the thoracic duct in management of chylothorax.

    Science.gov (United States)

    Icaza, Orlando J; Andrews, Kris; Kuhnke, Mark

    2002-04-01

    Laparoscopic ligation of the cisterna chyli at the level of the aortic hiatus was performed in a 69-year-old woman with post-lobectomy chylothorax refractory to 3 weeks of conservative therapy and one repeat thoracotomy with attempted ligation of a leaking lymphatic channel. This laparoscopic procedure was successful, and resolution of the chylothorax was achieved. We feel that this technique offers surgeons a valid, minimally invasive treatment option for a persistent chylothorax in which conservative management or more direct thoracic procedures have failed to control the chyle leak. PMID:12019574

  15. Characterizing the plasticity of nitrogen metabolism by the host and symbionts of the hydrothermal vent chemoautotrophic symbioses Ridgeia piscesae.

    Science.gov (United States)

    Liao, Li; Wankel, Scott D; Wu, Min; Cavanaugh, Colleen M; Girguis, Peter R

    2014-03-01

    Chemoautotrophic symbionts of deep sea hydrothermal vent tubeworms are known to provide their hosts with all their primary nutrition. While studies have examined how chemoautotrophic symbionts provide the association with nitrogen, fewer have examined if symbiont nitrogen metabolism varies as a function of environmental conditions. Ridgeia piscesae tubeworms flourish at Northeastern Pacific vents, occupy a range of microhabitats, and exhibit a high degree of morphological plasticity [e.g. long-skinny (LS) and short-fat (SF) phenotypes] that may relate to environmental conditions. This plasticity affords an opportunity to examine whether symbiont nitrogen metabolism varies among host phenotypes. LS and SF R. piscesae were recovered from the Axial and Main Endeavour Field hydrothermal vents. Nitrate and ammonium were quantified in Ridgeia blood, and the expression of key nitrogen metabolism genes, as well as stable nitrogen isotope ratios, was quantified in host branchial plume and symbiont-containing tissues. Nitrate and ammonium were abundant in the blood of both phenotypes though environmental ammonium concentrations were, paradoxically, lowest among individuals with the highest blood ammonium. Assimilatory nitrate reductase transcripts were always below detection, though in both LS and SF R. piscesae symbionts, we observed elevated expression of dissimilatory nitrate reductase genes, as well as symbiont and host ammonium assimilation genes. Site-specific differences in expression, along with tissue stable isotope analyses, suggest that LS and SF Ridgeia symbionts are engaged in both dissimilatory nitrate reduction and ammonia assimilation to varying degrees. As such, it appears that environmental conditions -not host phenotype-primarily dictates symbiont nitrogen metabolism. PMID:24237389

  16. Characterization of hydrogen, nitrogen, oxygen, carbon and sulfur in nuclear fuel (UO2) and cladding nuclear rod materials

    International Nuclear Information System (INIS)

    The importance of Hydrogen, Nitrogen, Oxygen, Carbon and Sulfur gases analysis in nuclear fuels such as UO2, U3O8, U3Si2 and in the fuel cladding such as Zircaloy, is a well known as a quality control in nuclear industry. In UO2 pellets, the Hydrogen molecule fragilizes the metal lattice causing the material cracking. In Zircaloy material the H2 molecules cause the boiling of the cladding. Other gases like Nitrogen, Oxygen, Carbon and Sulfur affect in the lattice structure change. In this way these chemical compounds have to be measure within specify parameters, these measurement are part of the quality control of the nuclear industry. The analytical procedure has to be well established by a convention of the quality assurance. Therefore, the Oxygen, Carbon, Sulfur and Hydrogen are measured by infrared absorption (IR) and the nitrogen will be measured by thermal conductivity (TC). The gas/metal analyzer made by LECO Co. model TCHEN-600 is Hydrogen, Oxygen and Nitrogen analyzer in a variety of metals, refractory and other inorganic materials, using the principle of fusion by inert gas, infrared and thermo-coupled detector. The Carbon and Sulfur compounds are measure by LECO Co. model CS-400. A sample is first weighed and placed in a high purity graphite crucible and is casted on a stream of helium gas, enough to release the oxygen, nitrogen and hydrogen. During the fusion, the oxygen present in the sample combines with the carbon crucible to form carbon monoxide. Then, the nitrogen present in the sample is analyzed and released as molecular nitrogen and the hydrogen is released as gas. The hydrogen gas is measured by infrared absorption, and the sample gases pass through a trap of copper oxide which converts CO to CO2 and hydrogen into water. The gases enter the cell where infrared water content is then converted making the measurement of total hydrogen present in the sample. The Hydrogen detection limits for the nuclear fuel is 1 μg/g for the Nitrogen and Oxygen

  17. Nitrogen vacancy complexes in nitrogen irradiated metals

    International Nuclear Information System (INIS)

    Gas desorption and positron annihilation techniques have been employed to study the evolution of nitrogen associated defects in nitrogen irradiated metals: Fe, Ni, Mo and W. Nitrogen in these metals has a rather high affinity to vacancy type defects. The results obtained for low irradiation dose show that substitutional nitrogen (NV; with V = vacancy) is formed. The nitrogen vacancy complex dissociates at temperatures ranging from 350 K for Ni to 900 K for Mo and 1,100 K for W. At high doses defects are formed which can be characterized as nitrogen saturated vacancy clusters. These defect, as observed by helium probing, disappear during annealing for nickel at 800 K, and for Mo at 1,100 K. The direct observation of the desorbing nitrogen for nickel and molybdenum reveals a very fast desorption transient at the dissociation temperature of the clusters. This is the characteristic desorption transient of a small nitride cluster, e.g., by shrinkage with constant rate. For iron the nitrogen desorption is more complicated because of a general background that continuously rises with temperature. With the positron beam technique depth information was obtained for defects in iron and the defect character could be established with the help of the information provided on annihilation with conduction and core electrons of the defect trapped positrons

  18. Characterization of growth, nitrogen accumulation and competitive ability of six tropical legumes for potential use in intercropping systems

    NARCIS (Netherlands)

    Akanvou, R.; Bastiaans, L.; Kropff, M.J.; Goudriaan, J.; Becker, M.

    2001-01-01

    Legume cover crops can be successfully used as intercrop or relay crops in low-input farming systems. To select appropriate species for intercropping, experiments were conducted in the savannah zone of Côte d'Ivoire during the wet seasons of 1997 and 1998 to determine the growth and nitrogen (N) acc

  19. Chemical characterization of manure in relation to manure quality as a contribution to a reduced nitrogen emission to the environment

    NARCIS (Netherlands)

    Stelt, van der B.

    2007-01-01

    Keywords:manure composition, ammonia volatilization, free ions, Donnan Membrane Technique, manure additives, dietary changes, nitrogen dynamics,grasslandsoils.More insight in manure composition, ammonia (NH 3 ) volatilizatio

  20. Growth and characterization of nitrogen-doped TiO2 thin films prepared by reactive pulsed laser deposition

    International Nuclear Information System (INIS)

    Nitrogen-doped titanium dioxide (TiO2) thin films were grown on (001) SiO2 substrates by reactive pulsed laser deposition. A KrF* excimer laser source (λ = 248 nm, τFWHM ≅ 10 ns, ν = 10 Hz) was used for the irradiations of pressed powder targets composed by both anatase and rutile phase TiO2. The experiments were performed in a controlled reactive atmosphere consisting of oxygen or mixtures of oxygen and nitrogen gases. The obtained thin film crystal structure was investigated by X-ray diffraction, while their chemical composition as well as chemical bonding states between the elements were studied by X-ray photoelectron spectroscopy. An interrelation was found between nitrogen concentration, crystalline structure, bonding states between the elements, and the formation of titanium oxinitride compounds. Moreover, as a result of the nitrogen incorporation in the films a continuous red-shift of the optical absorption edge accompanied by absorption in the visible spectral range between 400 and 500 nm wavelength was observed.

  1. Characterization of the start-up period of single-step autotrophic nitrogen removal in a sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    GUO Jin-song; QIN Yu; FANG Fang; YANG Guo-hong

    2008-01-01

    The characteristics of the start-up period of single-step autotrophic nitrogen removal process were investigated. The autotrophic nitrogen removal process used a sequencing batch reactor to treat wastewater of medium to low ammonia-nitrogen concentration, with dissolved oxygen (DO), hydraulic retention time (HRT) and temperature controlled. The experimental conditions were temperature at (30(2) (C, ammonia concentration of (60 to 120) mg/L, DO of (0.8 to 1.0) mg/L, pH from 7.8 to 8.5 and HRT of 24 h. The rates of nitrification and nitrogen removal turn out to be 77% and 40%, respectively, after a start up period going through three stages divided according to nitrite accumulation: sludge domestication, nitrifying bacteria selection and sludge adaptation. It is demonstrated that dissolved oxygen is critical to nitrite accumulation and elastic YJZH soft compound packing is superior to polyhedral hollow balls in helping the bacteria adhere to the membrane.

  2. Synthesis and Characterization of Cobalt(II, Nickel(II and Copper(II Complexes with Nitrogen-Oxygen Donor Ligand

    Directory of Open Access Journals (Sweden)

    B. K. Rai

    2014-09-01

    Full Text Available The complexes of ML2 were synthesized where M= Co(II, Ni(II and Cu(II and L= 2-Butyl thioquinazoline 4 (3H- semicarbazone (BTQS. The ligand have been synthesized by condensation of thioquinazoline-4(3H-one with semicarbazide hydrochlande characterized by molar mass, elemental analysis, Infrared spectra, electronic spectra, magnetic susceptibility and molar conductance measurements .The ligand BTQS acts as neutral bidentate chelating agent and coordinated to metal ions through azomethine nitrogen and carbonyl oxygen of semicarbazone moiety. The remaining Coordination centres are satisfied by anions such as Cl-, Br-, I- and NO3-.

  3. Synthesis and Characterization of Cu(II, Ni(II And Co(II Coordination Compounds with Nitrogen and Oxygen Containing Schiff Base

    Directory of Open Access Journals (Sweden)

    Rajeshwar Rai

    2014-03-01

    Full Text Available Octahedral complexes has been designed and synthesized by a 2-propyl-thioquinozoline 4(3H semicarbazone (PTQS with Co(II, Ni(II and Cu(II metal ions. The complexes was characterized by molar mass, elemental analyses, IR electronic spectra, Molar conductivity and magnetic susceptibility assistance. On the above studies it was confirming that metal ions was coordinated with Carbonyl oxygen and azomethine nitrogen atom of semicarbazone moiety. The remaining valency of metal ions are satisfied by negative ions such as Cl–, Br–, I– and No3– ions.

  4. The effect of ligation method on friction in sliding mechanics.

    Science.gov (United States)

    Hain, Max; Dhopatkar, Ashish; Rock, Peter

    2003-04-01

    During orthodontic tooth movement with the preadjusted edgewise system, friction generated at the bracket/archwire interface tends to impede the desired movement. The method of ligation is an important contributor to this frictional force. This in vitro study investigated the effect of ligation method on friction and evaluated the efficacy of the new slick elastomeric modules from TP Orthodontics (La Porte, Ind), which are claimed to reduce friction at the module/wire interface. Slick modules were compared with regular nonslick modules, stainless steel ligatures, and the SPEED self-ligating bracket system (Strite Industries, Cambridge, Ontario, Canada). The effect of using slick modules with metal-reinforced ceramic (Clarity, 3M Unitek, Monrovia, Calif) and miniature brackets (Minitwin, 3M Unitek) was also examined. Results showed that, when considering tooth movement along a 0.019 x 0.025-in stainless steel archwire, saliva-lubricated slick modules can reduce static friction at the module/archwire interface by up to 60%, regardless of the bracket system. The SPEED brackets produced the lowest friction compared with the 3 other tested bracket systems when regular modules were used. The use of slick modules, however, with all of the ligated bracket types tested significantly reduced friction to below the values recorded in the SPEED groups. Loosely tied stainless steel ligatures were found to generate the least friction. PMID:12695769

  5. Kinetic framework for ligation by an efficient RNA ligase ribozyme.

    Science.gov (United States)

    Bergman, N H; Johnston, W K; Bartel, D P

    2000-03-21

    The class I RNA ligase ribozyme, isolated previously from random sequences, performs an efficient RNA ligation reaction. It ligates two substrate RNAs, promoting the attack of the 3'-hydroxyl of one substrate upon the 5'-triphosphate of the other substrate with release of pyrophosphate. This ligation reaction has similarities to the reaction catalyzed by RNA polymerases. Using data from steady-state kinetic measurements and pulse-chase/pH-jump experiments, we have constructed minimal kinetic frameworks for two versions of the class I ligase, named 207t and 210t. For both ligases, as well as for the self-ligating parent ribozyme, the rate constant for the chemical step (k(c)) is log-linear with pH in the range 5.7-8.0. At physiological pH, the k(c) is 100 min(-1), a value similar to those reported for the fastest naturally occurring ribozymes. At higher pH, product release is limiting for both 207t and 210t. The 210t ribozyme, with its faster product release, attains multiple-turnover rates (k(cat) = 360 min(-1), pH 9.0) exceeding those of 207t and other reported ribozyme reactions. The kinetic framework for the 210t ribozyme describes the limits of this catalysis and suggests how key steps can be targeted for improvement using design or combinatorial approaches. PMID:10715133

  6. Adrenal function in preterm infants undergoing patent ductus arteriosus ligation.

    LENUS (Irish Health Repository)

    El-Khuffash, Afif

    2013-01-01

    Targeted milrinone treatment for low left ventricular output (LVO) reduces the incidence of acute cardiorespiratory instability following ligation of patent ductus arteriosus (PDA) in preterm infants. Despite this, some infants continue to experience postoperative deterioration. Adrenal insufficiency related to prematurity has been postulated as a possible mechanism.

  7. Synthesis of coumarin or ferrocene labeled nucleosides via Staudinger ligation

    Directory of Open Access Journals (Sweden)

    Kois Pavol

    2006-11-01

    Full Text Available Abstract Background Reaction of azides with triaryl phosphines under mild conditions gives iminophosphoranes which can react with almost any kind of electrophilic reagent, e.g. aldehydes/ketones to form imines or esters to form amides. This so-called Staudinger ligation has been employed in a wide range of applications as a general tool for bioconjugation including specific labeling of nucleic acids. Results A new approach for the preparation of labeled nucleosides via intermolecular Staudinger ligation is described. Reaction of azidonucleosides with triphenylphosphine lead to iminophosphorane intermediates, which react subsequently with derivatives of coumarin or ferrocene to form coumarin or ferrocene labeled nucleosides. Fluorescent properties of coumarin labeled nucleosides are determined. Conclusion New coumarin and ferrocene labeled nucleosides were prepared via intermolecular Staudinger ligation. This reaction joins the fluorescent coumarin and biospecific nucleoside to the new molecule with promising fluorescent and electrochemical properties. The isolated yields of products depend on the structure of azidonucleoside and carboxylic acids. A detailed study of the kinetics of the Staudinger ligation with nucleoside substrates is in progress.

  8. Ectopic pregnancy after two times tubal ligation: a case report

    Directory of Open Access Journals (Sweden)

    Farideh Keypour

    2013-06-01

    Full Text Available Background: Tubal sterilization is the permanent and effective contraception method. This can be performed at any time, but at least half are performed in conjunction with cesarean or vaginal delivery and are termed puerperal. The most complication after tubal ligation is ectopic pregnancy. Ectopic pregnancy is the leading cause of maternal death in first trimester.Case presentation: We present a 33 years old woman gravida5, para4, all normal vaginal delivery, presented with complaints of delayed menstrual period, pelvic pain and spotting. She underwent tubal ligation for two times. For the first time she had puerperal Pomeroy tubal sterilization after third child delivery. Intra uterine pregnancy occurred three years later. One day after vaginal delivery of fourth child, she underwent post partum tubal ligation with the Parkland method. Tubal pregnancy occurred nine months later. Physical examination identified acute abdomen. Pelvic ultrasound showed no gestational sac in uterine cavity. The sac with fetal pole was in right adnexa. Beta-HCG was 2840mIU/ml. She underwent laparotomy. Surgical management included salpingectomy with cornual resection in both sides. The surgery identified Ectopic pregnancy.Conclusion: Any symptoms of pregnancy in a woman after tubal ligation must be investigated; an ectopic pregnancy should be excluded. Ectopic pregnancy must be considered, in any woman with lower abdominal pain, missed period and vaginal bleed-ing. Conception after tubal sterilization can be explained by fistula formation and re-canalization of fallopian tube.

  9. PUNICA GRANATUM ATTENUATES SCIATIC NERVE LIGATION INDUCED-NEUROPATHIC PAIN

    Directory of Open Access Journals (Sweden)

    Ramica Sharma et al.

    2012-02-01

    Full Text Available The study has been designed to investigate the effect of aqueous extract of rind of Punica granatum in sciatic nerve ligation induced-neuropathic pain in rats. Surgical procedure was performed with sciatic nerve ligation to develop neuropathic pain in rats. The development of neuropathic pain was assessed by employing behaviour parameters such as hyperalgesia and allodynia. Further, the functionality of sciatic nerve was assessed using the histopathological study of myelinated and unmyelinated fibers in sciatic nerve. Moreover, the oxidative stress was assessed by estimating serum thiobarbituric acid reactive substances (TBARS, catalase, glutathione and tissue TBARS and Superoxide dismutase (SOD. Rats exposed to sciatic nerve ligation produced marked increase in oxidative stress, which was assessed in terms of TBARS and SOD along with decrease in the level of catalase and glutathione. Moreover, it develops neuropathic pain by impairing the normal functions of myelinated and unmyelinated fibers in sciatic nerve. Treatment with aqueous extract of Punica granatum extract (100mg/kg, p.o markedly prevented sciatic nerve ligation-induced neuropathy and oxidative stress by increasing the pain threshold, by improving the functionality of sciatic nerve, by decreasing serum and tissue TBARS and tissue SOD, by increasing levels of serum glutathione and catalase. It may be concluded that Punica granatum extract reduced the oxidative stress via inhibiting p38MAPK and alleviates neuropathic symptoms and consequently improved the functionality of sciatic nerve and prevents sciatic nerve ligation–induced neuropathic pain.

  10. Subfascial endoscopic ligation in the treatment of incompetent perforating veins

    NARCIS (Netherlands)

    E.G.J.M. Pierik; C.H. Wittens; H. van Urk (Hero)

    1995-01-01

    textabstractObjectives: To assess the technique of subfascial endoscopic ligation of incompetent perforatory veins by use of a mediastinoscope. Design: Prospective open clinic study. Setting: Two Departments of Surgery. Materials and Methods: Thirty-eight consecutive patients (40 legs) with recu

  11. Assessment and treatment of post patent ductus arteriosus ligation syndrome.

    LENUS (Irish Health Repository)

    El-Khuffash, Afif F

    2014-07-01

    To compare differences in tissue Doppler imaging, global longitudinal strain (GLS), and cardiac troponin T (cTnT) between infants with low (<200 mL\\/kg\\/min) and high (>200 mL\\/kg\\/min) left ventricular (LV) output 1 hour after duct ligation and assess the impact of milrinone treatment on cardiac output and myocardial performance.

  12. Endoscopic banding ligation can effectively resect hyperplastic Polyps of stomach

    Institute of Scientific and Technical Information of China (English)

    Ching-Chu Lo; Wen-Chi Chen; E-Ming Wang; Kwok-Hung Lai; Ping-I Hsu; Gin-Ho Lo; Hui-Hwa Tseng; Hui-Chun Chen; Ping-Ning Hsu; Chiun-Ku Lin; Hoi-Hung Chan; Wei-Lun Tsai

    2003-01-01

    AIM: Bleeding and perforation are the major and serious complications associated with endoscopic polypectomy. To develop a safe and effective method to resect hyperplastic polyps of the stomach, we employed rubber bands to strangulate hyperplastic polyps and to determine the possibility of inducing avascular necrosis in these lesions.METHODS: Forty-seven patients with 72 hyperplastic polyps were treated with endoscopic banding ligation (EBL). On 14 days after endoscopic ligation, follow-up endoscopies were performed to assess the outcomes of the strangulated polyps.RESULTS: After being strangulated by the rubber bands,all of the polyps immediately became congested (100 %),and then developed cyanotic changes (100 %) approximately 4 minutes later. On follow-up endoscopy 2 weeks later, all the polyps except one had dropped off. The only one residual polyp shrank with a rubber band in its base, and it also dropped off spontaneously during subsequent follow-up.No complications occurred during or following the ligation procedures.CONCLUSION: Gastric polyps develop avascular necrosis following ligation by rubber bands. Employing suction equipment, EBL can easily capture sessile polyps. It is an easy, safe and effective method to eradicate hyperplastic polyps of the stomach.

  13. Infrared coagulation versus rubber band ligation in early stage hemorrhoids

    Directory of Open Access Journals (Sweden)

    P.J. Gupta

    2003-10-01

    Full Text Available The ideal therapy for early stages of hemorrhoids is always debated. Some are more effective but are more painful, others are less painful but their efficacy is also lower. Thus, comfort or efficacy is a major concern. In the present randomized study, a comparison is made between infrared coagulation and rubber band ligation in terms of effectiveness and discomfort. One hundred patients with second degree bleeding piles were randomized prospectively to either rubber band ligation (N = 54 or infrared coagulation (N = 46. Parameters measured included postoperative discomfort and pain, time to return to work, relief in incidence of bleeding, and recurrence rate. The mean age was 38 years (range 19-68 years. The mean duration of disease was 17.5 months (range 12 to 34 months. The number of male patients was double that of females. Postoperative pain during the first week was more intense in the band ligation group (2-5 vs 0-3 on a visual analogue scale. Post-defecation pain was more intense with band ligation and so was rectal tenesmus (P = 0.0059. The patients in the infrared coagulation group resumed their duties earlier (2 vs 4 days, P = 0.03, but also had a higher recurrence or failure rate (P = 0.03. Thus, we conclude that band ligation, although more effective in controlling symptoms and obliterating hemorrhoids, is associated with more pain and discomfort to the patient. As infrared coagulation can be conveniently repeated in case of recurrence, it could be considered to be a suitable alternative office procedure for the treatment of early stage hemorrhoids.

  14. Level of arterial ligation in rectal cancer surgery: Low tie preferred over high tie. A review

    NARCIS (Netherlands)

    M.M. Lange (Marilyne); M. Buunen (Mark); C.J.H. van de Velde (Cornelis)

    2008-01-01

    textabstractConsensus does not exist on the level of arterial ligation in rectal cancer surgery. From oncologic considerations, many surgeons apply high tie arterial ligation (level of inferior mesenteric artery). Other strategies include ligation at the level of the superior rectal artery, just cau

  15. Spontaneous Synthesis and Electrochemical Characterization of Nanostructured MnO2 on Nitrogen-Incorporated Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Ying-Chu Chen

    2012-01-01

    Full Text Available This paper investigated the layered manganese dioxide with hydrate (MnO2⋅xH2O deposits onto nitrogen-containing carbon nanotube (CNxNTs as a hierarchical electrode for an energy-storage device. The dense and entangled CNxNTs were directly grown by microwave plasma-enhanced chemical vapor deposition (MPECVD on a carbon cloth (CC, and subsequently used as a current collector. By controlling the pH value of KMnO4 precursor solution, and incorporating nitrogen into CNTs as a reducing agent, the MnO2 thin layer was uniformly fabricated on the CNxNTs at room temperature by using a spontaneous reduction method. The role of incorporation nitrogen is not only capable of creating active sites on the CNT surface, but can also donate electrons to reduce MnO4- to MnO2 spontaneously. From the measurements of cyclic voltammograms and galvanostatic charge/discharge, MnO2/CNxNTs/CC composite electrodes illustrated excellent specific capacitance of 589.1 Fg-1. The key factor for high performance could be attributed to the thin-layered MnO2 nanostructure, which resulted in the full utilization of MnO2 deposits. Hence, the hierarchically porous MnO2/CNxNTs/CC electrodes exhibited excellent capacitive behavior for electrochemical capacitor application.

  16. Enzymes involved in DNA ligation and end-healing in the radioresistant bacterium Deinococcus radiodurans

    Directory of Open Access Journals (Sweden)

    Shevelev Igor V

    2007-08-01

    Full Text Available Abstract Background Enzymes involved in DNA metabolic events of the highly radioresistant bacterium Deinococcus radiodurans are currently examined to understand the mechanisms that protect and repair the Deinococcus radiodurans genome after extremely high doses of γ-irradiation. Although several Deinococcus radiodurans DNA repair enzymes have been characterised, no biochemical data is available for DNA ligation and DNA endhealing enzymes of Deinococcus radiodurans so far. DNA ligases are necessary to seal broken DNA backbones during replication, repair and recombination. In addition, ionizing radiation frequently leaves DNA strand-breaks that are not feasible for ligation and thus require end-healing by a 5'-polynucleotide kinase or a 3'-phosphatase. We expect that DNA ligases and end-processing enzymes play an important role in Deinococcus radiodurans DNA strand-break repair. Results In this report, we describe the cloning and expression of a Deinococcus radiodurans DNA ligase in Escherichia coli. This enzyme efficiently catalyses DNA ligation in the presence of Mn(II and NAD+ as cofactors and lysine 128 was found to be essential for its activity. We have also analysed a predicted second DNA ligase from Deinococcus radiodurans that is part of a putative DNA repair operon and shows sequence similarity to known ATP-dependent DNA ligases. We show that this enzyme possesses an adenylyltransferase activity using ATP, but is not functional as a DNA ligase by itself. Furthermore, we identified a 5'-polynucleotide kinase similar to human polynucleotide kinase that probably prepares DNA termini for subsequent ligation. Conclusion Deinococcus radiodurans contains a standard bacterial DNA ligase that uses NAD+ as a cofactor. Its enzymatic properties are similar to E. coli DNA ligase except for its preference for Mn(II as a metal cofactor. The function of a putative second DNA ligase remains unclear, but its adenylyltransferase activity classifies it as a

  17. Ligation-free ribosome profiling of cell type-specific translation in the brain.

    Science.gov (United States)

    Hornstein, Nicholas; Torres, Daniela; Das Sharma, Sohani; Tang, Guomei; Canoll, Peter; Sims, Peter A

    2016-01-01

    Ribosome profiling has emerged as a powerful tool for genome-wide measurements of translation, but library construction requires multiple ligation steps and remains cumbersome relative to more conventional deep-sequencing experiments. We report a new, ligation-free approach to ribosome profiling that does not require ligation. Library construction for ligation-free ribosome profiling can be completed in one day with as little as 1 ng of purified RNA footprints. We apply ligation-free ribosome profiling to mouse brain tissue to identify new patterns of cell type-specific translation and test its ability to identify translational targets of mTOR signaling in the brain.

  18. Electrical detection of amine ligation to a metalloporphyrin via a hybrid SOI-MOSFET.

    Science.gov (United States)

    Takulapalli, Bharath R; Laws, Gez M; Liddell, Paul A; Andréasson, Joakim; Erno, Zach; Gust, Devens; Thornton, Trevor J

    2008-02-20

    A close-packed monolayer of zinc 5,10,15,20-tetrakis(3-carboxyphenyl)porphyrin has been prepared and deposited on the thin native oxide covering the surface of an SOI-MOSFET (silicon-on-insulator metal-oxide-semiconductor field effect transistor) using Langmuir-Blodgett techniques. When the device is exposed to amine vapors in a nitrogen atmosphere, the amine coordinates to the zinc atom. The resulting change in electron distribution within the porphyrin leads to a large change in the drain current of the transistor, biased via a back gate. This change is sensitive to both the amount of amine present and the base strength of the amine. Only very small changes in drain current were observed with a monolayer of free base porphyrin or palmitic acid. After exposure to high pyridine concentrations, the device response saturates, but partially recovers after overnight exposure to flowing nitrogen gas. Interestingly, the device response is instantaneously reset by exposure to visible light, suggesting that photode-ligation occurs. An electrical model for the hybrid device that describes its response to ligand binding in terms of a change in the work function of the porphyrin monolayer has been developed. A transistor response to a few hundred attomoles of bound pyridine can be readily detected. This extreme sensitivity, coupled with the ability to reset the device using light, suggests that such systems might be useful as sensors. PMID:18225896

  19. Extended X-ray absorption fine structure studies of Zn/sub 2/Fe/sub 2/ hybrid hemoglobins: absence of heme bond length changes in half-ligated species

    Energy Technology Data Exchange (ETDEWEB)

    Simolo, K.; Korszun, Z.R.; Stucky, G.; Moffat, K.; McLendon, G.

    1986-07-01

    Metal hybrid hemoglobins, in which Zn(II) replaces Fe(II), have been structurally characterized by extended X-ray absorption structure (EAFS) studies. Since Zn and Fe have very different K absorption edge energies, the structures of the ligated (Fe) and unligated (Zn) sites could be examined independently within a single molecule that mimics an intermediate ligation state. The observed EXAFS spectra and associated structural parameters are compared among the ligand free (..cap alpha..Zn)/sub 2/(..beta..Zn)/sub 2/, half-ligated (..cap alpha..FeCO)/sub 2/(..beta..Zn)/sub 2/ and (..cap alpha..Zn)/sub 2/(..beta..FeCO)/sub 2/, and fully ligated (..cap alpha..FeCO)/sub 2/(..beta..FeCO)/sub 2/ systems.

  20. Characterization of pII Family (GlnK1, GlnK2, GlnB) Protein Uridylylation in Response to Nitrogen Availability for Rhodopseudomonas palustris

    Energy Technology Data Exchange (ETDEWEB)

    Connelly, Heather M [ORNL; Pelletier, Dale A [ORNL; Lu, Tse-Yuan [ORNL; Lankford, Patricia K [ORNL; Hettich, Robert {Bob} L [ORNL

    2006-01-01

    The GlnK and GlnB proteins are members of the pII signal transduction protein family, which is essential in nitrogen regulation due to this protein family's ability to sense internal cellular ammonium levels and control cellular response. The role of GlnK in nitrogen regulation has been studied in a variety of bacteria but previously has been uncharacterized in the purple nonsulfur anoxygenic phototropic bacterium Rhodopseudomonas palustris. R. palustris has tremendous metabolic versatility in its modes of energy generation and carbon metabolism, and it employs a sensitive nitrogen-ammonium regulation system that may vary from that of other commonly studied bacteria. In R. palustris, there are three annotated forms of pII proteins: GlnK1, GlnK2, and GlnB. Here we describe, for the first time, the characterization of GlnK1, GlnK2, and GlnB modifications as a response to nitrogen availability, thereby providing information about how this bacterium regulates the AmtB ammonium transporter and glutamine synthetase, which controls the rate of glutamate to glutamine conversion. Using a strategy of creating C-terminally tagged GlnK and GlnB proteins followed by tandem affinity purification in combination with top-down mass spectrometry, four isoforms of the GlnK2 and GlnB proteins and two isoforms of the GlnK1 protein were characterized at high resolution and mass accuracy. Wild-type or endogenous expression of all three proteins was also examined under normal ammonium conditions and ammonium starvation to ensure that the tagging and affinity purification methods employed did not alter the natural state of the proteins. All three proteins were found to undergo uridylylation under ammonium starvation conditions, presumably to regulate the AmtB ammonium transporter and glutamine synthetase. Under high-ammonium conditions, the GlnK1, GlnK2, and GlnB proteins are unmodified. This experimental protocol involving high-resolution mass spectrometry measurements of intact

  1. Ligation of Glycophorin A Generates Reactive Oxygen Species Leading to Decreased Red Blood Cell Function

    Science.gov (United States)

    Khoory, Joseph; Estanislau, Jessica; Elkhal, Abdallah; Lazaar, Asmae; Melhorn, Mark I.; Brodsky, Abigail; Illigens, Ben; Hamachi, Itaru; Kurishita, Yasutaka; Ivanov, Alexander R.; Shevkoplyas, Sergey; Shapiro, Nathan I.; Ghiran, Ionita C.

    2016-01-01

    Acute, inflammatory conditions associated with dysregulated complement activation are characterized by significant increases in blood concentration of reactive oxygen species (ROS) and ATP. The mechanisms by which these molecules arise are not fully understood. In this study, using luminometric- and fluorescence-based methods, we show that ligation of glycophorin A (GPA) on human red blood cells (RBCs) results in a 2.1-fold, NADPH-oxidase-dependent increase in intracellular ROS that, in turn, trigger multiple downstream cascades leading to caspase-3 activation, ATP release, and increased band 3 phosphorylation. Functionally, using 2D microchannels to assess membrane deformability, GPS-ligated RBCs travel 33% slower than control RBCs, and lipid mobility was hindered by 10% using fluorescence recovery after photobleaching (FRAP). These outcomes were preventable by pretreating RBCs with cell-permeable ROS scavenger glutathione monoethyl ester (GSH-ME). Our results obtained in vitro using anti-GPA antibodies were validated using complement-altered RBCs isolated from control and septic patients. Our results suggest that during inflammatory conditions, circulating RBCs significantly contribute to capillary flow dysfunctions, and constitute an important but overlooked source of intravascular ROS and ATP, both critical mediators responsible for endothelial cell activation, microcirculation impairment, platelet activation, as well as long-term dysregulated adaptive and innate immune responses. PMID:26784696

  2. SCREENING FOR ANTI ULCER ACTIVITY OF CONVOLVULUS PLURICAULIS USING PYLORIC LIGATION METHOD IN WISTER RATS.

    Directory of Open Access Journals (Sweden)

    Sharath S S

    2015-01-01

    Full Text Available Peptic ulcer disease is a chronic problem of the gastrointestinal tract characterized by mucosal damage secondary to pepsin and gastric acid secretion. Herbal medicines are generally used in cases when drugs are to be used for chronic periods. The study was conducted to evaluate antiulcerogenic activity of convolvulus pluricaulis in wistar rats. The antiulcer activity was carried out employing - Pyloric ligation method. The rats were randomly divided into 4 groups of 6 animals each. First group was given 1ml of 0.1% of vehicle (Tween 80; the second group was treated with ranitidine 50 mg/kg in 1 ml Tween 80. The remaining groups receive 200 mg/kg and 400 mg/kg of Convolvulus pluricaulis alcoholic extract (CPAE in 1 ml Tween 80 respectively. All the drugs were administered orally for five days duration daily in two divided doses. Evaluation of antiulcer activity was done by Ulcer score/ulcer index. Volume of gastric juice secreted, gastric free acidity, total acidity, total protein, pepsin mucin and pH were also estimated. CPAE at a dose of 200 mg/kg inhibited ulcer index by 40.87% and at a dose of 400 mg/kg inhibited ulcer index by 26.64 %. Alcoholic extracts of Convolvulus pluricaulis have shown a significant protection against gastric ulcers in pyloric ligation model.

  3. The nonenzymatic template-directed ligation of oligonucleotides

    Directory of Open Access Journals (Sweden)

    A.V. Lutay

    2006-01-01

    Full Text Available The nonenzymatic template-directed ligation of oligonucleotides containing 2',3'-cyclic phosphate was investigated in the presence of divalent cations. Ligation of the oligonucleotides readily occurred in the presence of Mg2+, Mn2+, Co2+, Zn2+, Pb2+. Efficacy of the metal ion catalysts inversely correlated with pKa values of the metal-bound water molecules. The intermolecular transesterification reaction yielded at least 95% of 2',5'-phosphodiester bonds independently on the nature of the metal ion. Relatively high reaction yields (up to 15% suggest, that RNA fragmentation to oligonucleotides with 2',3'-cyclic phosphates, followed by reactions of those oligonucleotides could provide a source of new RNA molecules under prebiotic conditions.

  4. Fabrication, characterization and application of nitrogen-containing carbon nanospheres obtained by pyrolysis of lignosulfonate/poly(2-ethylaniline).

    Science.gov (United States)

    He, Zhi-Wei; Lü, Qiu-Feng; Lin, Qilang

    2013-01-01

    Lignosulfonate/poly(2-ethylaniline) (LS-PEA) composite nanospheres were prepared via in situ polymerization of 2-ethylaniline (EA) with lignosulfonate (LS) as a dispersant. LS-PEA nanospheres with an average diameter of 155 nm were obtained at an optimal LS concentration of 20 wt.%. Subsequently, nitrogen-containing carbon nanospheres were fabricated via direct pyrolysis of the LS-PEA composite nanospheres at 600-800 °C. The carbon nanospheres prepared by pyrolysis were used as anodes of lithium-ion batteries. The first charge and discharge capacity of carbon nanospheres prepared at 700 °C at current densities of 60 and 100 mA g(-1) were 980 and 432 mAh g(-1), and 764 and 342 mAh g(-1), respectively. The batteries still owned a high capacity of 353 and 296 mAh g(-1) after 20 cycles. The results indicated that these nitrogen-containing carbon nanospheres could be used as a promising candidate for electrode materials of lithium-ion batteries.

  5. Characterization of a spontaneous mutant of Azotobacter vinelandii in which vanadium-dependent nitrogen fixation is not inhibited by molybdenum.

    Science.gov (United States)

    Bageshwar, U K; Raina, R; Das, H K

    1998-05-01

    A spontaneous mutant derivative of Azotobacter vinelandii CA12 (delta nif HDK), which vanadium-dependent nitrogen fixation is not inhibited by molybdenum (A. vinelandii CARR), grows profusely on BNF-agar containing 1 microM Na2MoO4, alone or supplemented with 1 microM V2O5. The expression of A. vinelandii vnfH::lacZ and vnfA::lacZ fusions in A. vinelandii CARR was not inhibited by 1 mM Na2MoO4, whereas molybdenum at much lower concentration inhibited the expression of vnfH::lacZ and vnfA::lacZ fusions in A. vinlandii CA12. The mutant also exhibited normal acetylene reduction activity in the presence of 1 microM Na2MoO4. The expression of A. vinelandii nifH::lacZ fusion in A. vinelandii CARR was low even though the cells were cultured under non-repressing conditions with urea as nitrogen source in the presence of Na2MoO4. The molybdenum content of A. vinelandii CARR cells was found to be about one-fourth that of A. vinelandii CA12. No nitrate reductase activity could be detected in A. vinelandii CARR when the cells were cultured in the presence of 10 microM Na2MoO4, whereas A. vinelandii CA12 exhibited some activity even with 100 pM Na2MoO4. PMID:9595678

  6. Total laparoscopic hysterectomy via suture and ligation technique

    OpenAIRE

    Kang, Hye Won; Lee, Ji Won; Ho Yeon KIM; Kim, Bo Wook; Moon, Chong Soo

    2016-01-01

    Objective The term 'total laparoscopic hysterectomy (TLH) with classical suture method' refers to a surgical procedure performed using only sutures and ligations with intracorporeal or extracorporeal ties, without using any laser or electronic cauterization devices during laparoscopic surgery as in total abdominal hysterectomy. However, the method is not as widely used as electric coagulation equipment for TLH because further advances in technology and surgical technique are required and oper...

  7. Elastic band ligation of hemorrhoids: Flexible gastroscope or rigid proctoscope?

    Institute of Scientific and Technical Information of China (English)

    M Cazemier; RJF Felt-Bersma; MA Cuesta; CJJ Mulder

    2007-01-01

    AIM: To compare rigid proctoscope and flexible endoscope for elastic band ligation of internal hemorrhoids.METHODS: Patients between 18 and 80 years old, with chronic complaints (blood loss, pain, itching or prolapse)of internal hemorrhoids of grade Ⅰ-Ⅲ, were randomized to elastic band ligation by rigid proctoscope or flexible endoscope (preloaded with 7 bands). Patients were retreated every 6 wk until the cessation of complaints.Evaluation by three-dimensional anal endosonography was performed.RESULTS: Forty-one patients were included (median age 52.0, range 27-79 years, 20 men). Nineteen patients were treated with a rigid proctoscope and twenty two with a flexible endoscope. Twenty-nine patients had grade Ⅰ hemorrhoids, 9 patients had grade Ⅱ hemorrhoids and 3 patients had grade Ⅲ hemorrhoids.All patients needed a minimum of 1 treatment and a maximum of 3 treatments. A median of 4.0 bands was used in the rigid proctoscope group and a median of 6.0 bands was used in the flexible endoscope group (P < 0.05). Pain after ligation tended to be more frequent in patients treated with the flexible endoscope (first treatment: 3 vs 10 patients, P < 0.05). Threedimensional endosonography showed no sphincter defects or alterations in submucosal thickness.CONCLUSION: Both techniques are easy to perform,well tolerated and have a good and fast effect. It is easier to perform more ligations with the flexible endoscope. Additional advantages of the flexible scope are the maneuverability and photographic documentation.However, treatment with the flexible endoscope might be more painful and is more expensive.

  8. LAD-Ligation: A Murine Model of Myocardial Infarction

    Science.gov (United States)

    Kolk, Mandy V.V.; Meyberg, Danja; Deuse, Tobias; Tang-Quan, Karis R.; Robbins, Robert C.; Reichenspurner, Hermann; Schrepfer, Sonja

    2009-01-01

    Research models of infarction and myocardial ischemia are essential to investigate the acute and chronic pathobiological and pathophysiological processes in myocardial ischemia and to develop and optimize future treatment. Two different methods of creating myocardial ischemia are performed in laboratory rodents. The first method is to create cryo infarction, a fast but inaccurate technique, where a cryo-pen is applied on the surface of the heart (1-3). Using this method the scientist can not guarantee that the cryo-scar leads to ischemia, also a vast myocardial injury is created that shows pathophysiological side effects that are not related to myocardial infarction. The second method is the permanent ligation of the left anterior descending artery (LAD). Here the LAD is ligated with one single stitch, forming an ischemia that can be seen almost immediately. By closing the LAD, no further blood flow is permitted in that area, while the surrounding myocardial tissue is nearly not affected. This surgical procedure imitates the pathobiological and pathophysiological aspects occurring in infarction-related myocardial ischemia. The method introduced in this video demonstrates the surgical procedure of a mouse infarction model by ligating the LAD. This model is convenient for pathobiological and pathophysiological as well as immunobiological studies on cardiac infarction. The shown technique provides high accuracy and correlates well with histological sections. PMID:19829290

  9. Characterizing the Spatial Pattern of Soil Carbon and Nitrogen Pools in the Turkey Lakes Watershed: A Comparison of Regression Techniques

    International Nuclear Information System (INIS)

    There is considerable spatial heterogeneity in organic carbon (C), total nitrogen (N), and potentially mineralizable nitrogen (PMN) pools in the soils of the Turkey Lakes Watershed. We hypothesized that topography regulates the spatial pattern of these pools through a combination of static factors (slope, aspect and elevation), which influence radiation, temperature and moisture conditions, and dynamic factors (catenary position,profile and planar curvature), which influence the transport of materials downslope. We used multiple linear regression (MLR)and tree regression (TR) models as exploratory techniques to determine if there was a topographic basis for the spatial pattern of the C, N and PMN pools. The MLR and TR models predicted similar integrated totals (i.e., within 5% of each other) but dissimilar spatial patterns of the pools. For the combined litter, fibric and hemic layer, the MLR models explained a significant portion of the variance (R2 = 0.38, 0.23 and0.28 for C, N and PMN, respectively), however, the residuals were large and biased (the smallest contents were over-predicted and the largest contents were under-predicted). The TR models (9-branch), in contrast, explained a greater portion of the variance (R2 = 0.75, 0.67 and 0.62 for C, N and PMN, respectively) and the residuals were smaller and unbiased. Based on our sampling strategy, the models suggested that static factors were most important in predicting the spatial pattern of the nutrient pools. However, a nested sampling strategy that included scales where both static (among hillslopes) and dynamic (within hillslope) factors result in a systematic variation in soil nutrient pools may have improved the predictive ability of the models

  10. Comparative study of classic friction among different archwire ligation systems

    Directory of Open Access Journals (Sweden)

    Gilberto Vilanova Queiroz

    2012-06-01

    Full Text Available OBJECTIVE: To describe and compare three alternative methods for controlling classical friction: Self-ligating brackets (SLB, special brackets (SB and special elastomeric ligatures (SEB. METHODS: The study compared Damon MX, Smart Clip, In-Ovation and Easy Clip self-ligating bracket systems, the special Synergy brackets and Morelli's twin bracket with special 8-shaped elastomeric ligatures. New and used Morelli brackets with new and used elastomeric ligatures were used as control. All brackets had 0.022 x 0.028-in slots. 0.014-in nickel-titanium and stainless steel 0.019 x 0.025-in wires were tied to first premolar steel brackets using each archwire ligation method and pulled by an Instron machine at a speed of 0.5 mm/minute. Prior to the mechanical tests the absence of binding in the device was ruled out. Statistical analysis consisted of the Kruskal-Wallis test and multiple non-parametric analyses at a 1% significance level. RESULTS: When a 0.014-in archwire was employed, all ligation methods exhibited classical friction forces close to zero, except Morelli brackets with new and old elastomeric ligatures, which displayed 64 and 44 centiNewtons, respectively. When a 0.019 x 0.025-in archwire was employed, all ligation methods exhibited values close to zero, except the In-Ovation brackets, which yielded 45 cN, and the Morelli brackets with new and old elastomeric ligatures, which displayed 82 and 49 centiNewtons, respectively. CONCLUSIONS: Damon MX, Easy Clip, Smart Clip, Synergy bracket systems and 8-shaped ligatures proved to be equally effective alternatives for controlling classical friction using 0.014-in nickel-titanium archwires and 0.019 x 0.025-in steel archwires, while the In-Ovation was efficient with 0.014-in archwires but with 0.019 x 0.025-in archwires it exhibited friction that was similar to conventional brackets with used elastomeric ligatures.

  11. Synthesis and Characterization of 4-Benzyloxybenzaldehyde-4-methyl-3-thiosemicarbazone (Containing Sulphur and Nitrogen Donor Atoms and Its Cd(II Complex

    Directory of Open Access Journals (Sweden)

    Lakshmi Narayana Suvarapu

    2015-12-01

    Full Text Available A chelating agent, 4-benzyloxybenzaldehyde-4-methyl-3-thiosemicarbazone (BBMTSC, containing sulphur and nitrogen donor atoms was synthesized and applied as a ligand for the chelation of Cd(II. Both the BBMTSC and its Cd(II complex were characterized by elemental analysis, UV-Vis absorption spectra, Fourier transform infrared spectroscopy (FT-IR, mass spectra, nuclear magnetic resonance spectroscopy (NMR, X-ray powder diffraction (XRD, and field emission scanning electron microscopy (FESEM. The FTIR spectra confirmed the formation of both BBMTSC and its Cd(II complex. XRD revealed the polycrystalline nature of the synthesized compounds. BBMTSC exhibited a flake-like micro-rod morphology, whereas the Cd(II complex had a flower-like nanorod structure.

  12. In vitro evaluation of resistance to sliding in self-ligating and conventional bracket systems during dental alignment

    OpenAIRE

    Cordasco, Giancarlo; Lo Giudice, Antonino; Militi, Angela; Nucera, Riccardo; Triolo, Giuseppe; Matarese, Giovanni

    2012-01-01

    Objective To investigate the resistance to sliding (RS) in self-ligating and conventional ligation bracket systems at 5 different second-order bracket angulations by using low-stiffness alignment wires in a 3-bracket experimental model and to verify the performance of the main RS components in both systems when these wires are used. Methods Interactive self-ligating brackets with closed and open slides were used for the self-ligating (SL) and conventional ligation (CL) groups, respectively; e...

  13. Deposition and field-emission characterization of electrically conductive nitrogen-doped diamond-like amorphous carbon films

    International Nuclear Information System (INIS)

    For the fabrication of high performance field emitters, diamond-like amorphous carbon films doped with nitrogen (DAC:N) were formed using an intermittent supermagnetron plasma chemical vapor deposition technique. DAC:N films were deposited using isobutane plasma to investigate the influence of discharge-off time and electrode spacing on the physical properties of the films at upper- and lower-electrode radio frequency (rf) powers (LORF) of 800 W/50-800 W. At LORF of 100 W, a discharge-on time of 1 min, and a discharge-off time (cooling time) of 30 s-10 min, resistivity was decreased with a decrease of the cooling time. By reducing the electrode spacing from 60 to 20 mm at a LORF of 50 and 800 W, the optical band gap of DAC:N film was decreased from 0.85 and 0.23 eV to 0.6 and 0 eV, respectively. A flat DAC:N film of 700 A thickness was deposited on a n-Si wafer at rf powers of 800 W/800 W. Using this flat DAC:N film, a threshold electric field of 18 V/μm was observed and maximum field-emission current density of 2.2 mA/cm2 was observed at the electric field of 32 V/μm

  14. Isolation and characterization of a Sinorhizobium fredii mutant that cannot utilize proline as the sole carbon and nitrogen source

    Institute of Scientific and Technical Information of China (English)

    HUANG Sheng; BAI Xueliang; MA Qingsheng; TANG Xianlai; WU Bo

    2004-01-01

    Sinorhizobium fredii strain HN01 can use proline as the sole carbon and nitrogen source. A mutant strain GXHN100 unable to catabolize proline was screened from 6000 Tn5gusA5 random insertional mutants of S.fredii strain HN01. Sequencing analysis showed that an open reading frame, named pmrA (proline metabolic relative), was inserted by the Tn5gusA5. A positive clone, named pGXHN100 which containing 3.3kb foreign DNA fragment of S.fredii strain HN01, was isolated from a partial gene library of S.fredii HN01 by colony in situ hybridization. Sequence analysis showed that pGXHN100 contained the entire pmrA gene. The 3.3kb DNA fragment of pGXHN100 was cloned into a broad-host-range cosmid vector pLAFR3 to form plasmid pGXHN200 which was subsequently introduced into GXHN100 to form a complemented strain GXHN200. Plant test showed that GXHN100 was effective and no obvious changes in nitrogenase activity comparing with parental strain. But GXHN100 nodulated 2 days later on soybean and its nodulation efficiency and competitiveness were decreased. The complemented strain GXHN200 restored the nodulation efficiency and competitiveness of GXHN100 to the wild type.

  15. Characterization of nitrogen-fixing moderate halophilic cyanobacteria isolated from saline soils of Songnen Plain in China

    Institute of Scientific and Technical Information of China (English)

    Wei Zhang; Yujie Feng

    2008-01-01

    Twenty out of 200 isolates of cyanobacteria mainly from saline soils of Songnen Plain of China were successfully grown on BG11 N-free medium. The nitrogen-fixing activity was then demonstrated for the 20 isolates in modified BG11 medium using the acetylene reduction assay. All of them possessed appreciable nitrogenase activity (acetylene reduction) under non-saline conditions; however, at 5% NaCl only 60% of the isolates exhibited a high rate of this activity and 25% were completely negative under these conditions. The cyanobacteria isolates grew well in BG11 medium; nevertheless, growth of the majority of isolates was reduced by about 25-85% in the same medium containing 5% NaCl. Cellulolytic activity was detected in 50% of the 20 strains, amylolytic in 45%, and pectinolytic in 10% of the isolates. The cyanobacteria isolates showed also enzymatic activity under saline conditions (6%). The preliminary identification indicated that seven isolates were Nostoc, two were Microcystis, four were Oscillatoria, six were Anabaena, and one isolate was Synechococcus.

  16. High-pressure characterization of nitrogen-rich bis-triaminoguanidinium azotetrazolate (TAGzT) by in situ Raman spectroscopy.

    Science.gov (United States)

    Behler, K D; Ciezak-Jenkins, J A; Sausa, R C

    2013-02-28

    Compounds rich in nitrogen are attracting significant interest not only because of their high energy content but also because they are potentially more environmentally benign in comparison to conventional energetic materials. Given this interest, it is desirable to understand their molecular composition and structural variations with pressure to derive their stability and determine the conditions in which they transform physically or chemically. In this study, we examine the room-temperature isothermal compression behavior of bis-triaminoguanidinium azotetrazolate (TAGzT) by in situ Raman spectroscopy to pressures near 17 GPa. We assign the characteristic vibrational bands and report the effects of pressure on band intensity, line width, and frequency shift. Two prominent peaks near 1370 and 1470 cm(-1) arise from the C-N and N═N symmetric stretches, respectively. Overall, the intensity of these bands and others diminishes with pressure, and their spectral linewidths increase monotonically upon compression. The vibrational frequency modes blue shift linearly upon compression, indicating a generalized stiffening of the bonds as the pressure increases. These results, together with micro Raman spectroscopic analyses of the recovered, decompressed samples, suggest that TAGzT does not undergo any phase transitions within this pressure range. We estimate and report the C-N and N═N intermolecular bond lengths under compression. PMID:23343336

  17. Identification and characterization of phenylacetonitrile as a nitrogenous disinfection byproduct derived from chlorination of phenylalanine in drinking water.

    Science.gov (United States)

    Ma, Xiaoyan; Deng, Jing; Feng, Jiao; Shanaiah, Narasimhamurthy; Smiley, Elizabeth; Dietrich, Andrea M

    2016-10-01

    Unregulated disinfection byproducts (DBPs), including nitrogenous disinfection byproducts (N-DBPs), originating from chlorination of the precursor amino acid phenylalanine in aqueous systems, were identified in laboratory reactions and distributed tap. The major N-DBP identified was phenylacetonitrile, and minor DBPs of benzyl chloride, phenylacetaldehyde, 2-chlorobenzyl cyanide, and 2, 6-diphenylpyridine were also formed. Phenylacetonitrile was generated through decarboxylation, dechlorination and/or hydrolysis processes. With an aromatic structure, phenylacetonitrile has an unpleasant odor of various descriptors and an odor threshold concentration of 0.2 ppt-v as measured through gas chromatography-olfactometry. The half-life of phenylacetonitrile in reagent water and chlorinated water at 19 °C were 121 h and 792 h, respectively. The occurrence of phenylacetonitrile as an N-DBP in tap water was investigated for the first time; the results revealed that μg/L concentrations were present in nine different distributed drinking waters in China and the United States. Phenylacetonitrile deteriorates the aesthetic quality of drinking water and may present risk due to its prolonged existence in drinking water, especially in the presence of residual chlorine.

  18. Telmisartan attenuates hepatic fibrosis in bile duct-ligated rats

    Institute of Scientific and Technical Information of China (English)

    En-tong YI; Rui-xia LIU; Yan WEN; Cheng-hong YIN

    2012-01-01

    Aim: To evaluate the antifibrotic effect of telmisartan,an angiotensin Ⅱ receptor blocker,in bile duct-ligated rats.Methods: Adult Sprague-Dawley rats were allocated to 3 groups: sham-operated rats,model rats underwent common bile duct ligation (BDL),and BDL rats treated with telmisartan (8 mg/kg,po,for 4 weeks).The animals were sacrificed on d 29,and liver histology was examined,the Knodell and Ishak scores were assigned,and the expression of angiotensin-converting enzyme (ACE) and ACE2 was evaluated with immunohistochemical staining.The mRNAs and proteins associated with liver fibrosis were evaluated using RTQ-PCR and Western blot,respectively.Results: The mean fibrosis score of BDL rats treated with telmisartan was significantly lower than that of the model rats (1.66±0.87 vs 2.13±0.35,P=0.015).However,there was no significant difference in inflammation between the two groups,both of which showed moderate inflammation.Histologically,treatment with telmisartan significantly ameliorated BDL-caused the hepatic fibrosis.Treatment with telmisartan significantly upregulated the mRNA levels of ACE2 and MAS,and decreased the mRNA levels of ACE,angiotensin Ⅱ type 1 receptor (AT1-R),collagen type Ⅲ,and transforming growth factor β1 (TGF-β1).Moreover,treatment with telmisartan significantly increased the expression levels of ACE2 and MAS proteins,and inhibited the expression levels of ACE and AT1-R protein.Conclusion: Telmisartan attenuates liver fibrosis in bile duct-ligated rats via increasing ACE2 expression level.

  19. Protein synthesis by native chemical ligation: Expanded scope by using straightforward methodology

    OpenAIRE

    Tilman M Hackeng; Griffin, John H.; Dawson, Philip E.

    1999-01-01

    The total chemical synthesis of proteins has great potential for increasing our understanding of the molecular basis of protein function. The introduction of native chemical ligation techniques to join unprotected peptides next to a cysteine residue has greatly facilitated the synthesis of proteins of moderate size. Here, we describe a straightforward methodology that has enabled us to rapidly analyze the compatibility of the native chemical ligation strategy for X–Cys ligation sites, where X...

  20. Outcome following patent ductus arteriosus ligation in premature infants: a retrospective cohort analysis

    OpenAIRE

    Yates Robert; Tulloh Robert; Tillett Angela; Lee LLeona CL; Kelsall Wilf

    2006-01-01

    Abstract Background The patent ductus arteriosus (PDA) is an important problem in premature infants. Surgical PDA ligation is usually only be considered when medical treatment has either failed or was contraindicated. The aims of our study were to determine the mortality and morbidity following patent ductus arteriosus ligation in premature infants, and whether prostaglandin synthetase inhibitor (PSI) use prior to ligation affects outcome. Methods A retrospective case note review study to det...

  1. Amplification of target-specific, ligation-dependent circular probe.

    Science.gov (United States)

    Zhang, D Y; Brandwein, M; Hsuih, T C; Li, H

    1998-05-12

    We describe a novel polymerase chain reaction (PCR)-based gene amplification method utilizing a circularizable oligodeoxyribonucleotide probe (C-probe). The C-probe contains two target complementary regions located at each terminus and an interposed generic PCR primer binding region. The hybridization of C-probe to a target brings two termini in direct apposition as the complementary regions of C-probe wind around the target to form a double helix. Subsequent ligation of the two termini results in a covalently linked C-probe that becomes 'locked on to' the target. The circular nature of the C-probe allows for the generation of a multimeric single-stranded DNA (ssDNA) via extension of the antisense primer by Taq DNA polymerase along the C-probe and displacement of downstream strand, analogous to 'rolling circle' replication of bacteriophage in vivo. This multimeric ssDNA then serves as a template for multiple sense primers to hybridize, extend, and displace downstream DNA, generating a large ramified (branching) DNA complex. Subsequent thermocycling denatures the dsDNA and initiates the next round of primer extension and ramification. This model results in significantly improved amplification kinetics (super-exponential) as compared to conventional PCR. Our results show that the C-probe was 1000 times more sensitive than the corresponding linear hemiprobes for detecting Epstein-Barr virus early RNA. The C-probe not only increases the power of amplification but also offers a means for decontaminating carryover amplicons. As the ligated C-probes possess no free termini, they are resistant to exonuclease digestion, whereas contaminated linear amplicons are susceptible to digestion. Treatment of the ligation reaction mixture with exonuclease prior to amplification eliminated the amplicon contaminant, which could also have been co-amplified with the same PCR primers; only the ligated C-probes were amplified. The combined advantages of the C-probe and thermocycling have a

  2. Expressed protein ligation for metalloprotein design and engineering.

    Science.gov (United States)

    Clark, Kevin M; van der Donk, Wilfred A; Lu, Yi

    2009-01-01

    Metalloproteins contain highly specialized metal-binding sites that are designed to accept specific metal ions to maintain correct function. Although many of the sites have been modified with success, the relative paucity of functional group availability within proteinogenic amino acids can sometimes leave open questions about specific functions of the metal binding ligands. Attaining a more thorough analysis of individual amino acid function within metalloproteins has been realized using expressed protein ligation (EPL). Here we describe our recent efforts using EPL to incorporate nonproteinogenic cysteine and methionine analogues into the type 1 copper site found in Pseudomonas aeruginosa azurin.

  3. Triple pregnancy after tubal ligation,a case report

    Directory of Open Access Journals (Sweden)

    N. Rahbar

    2006-01-01

    Full Text Available We report a case of a triple pregnancy after tubal ligation (TL in a 24-year-old woman. The patient found out that she was pregnant about 2 years after TL. A live fetus and two other dead fetuses were reported in sonography at 17th week of pregnancy. In a determined time, Cesarean/Section and TL was done and the single term girl fetus and the two other dead fetuses in a papyrus form on the placenta were born.

  4. Zn(2+)-ligation DNAzyme-driven enzymatic and nonenzymatic cascades for the amplified detection of DNA.

    Science.gov (United States)

    Lu, Chun-Hua; Wang, Fuan; Willner, Itamar

    2012-06-27

    A generic fluorescence sensing platform for analyzing DNA by the Zn(2+)-dependent ligation DNAzyme as amplifying biocatalyst is presented. The platform is based on the target DNA induced ligation of two substrate subunits and the subsequent opening of a beacon hairpin probe by the ligated product. The strand displacement of the ligated product by the beacon hairpin is, however, of limited efficiency. Two strategies are implemented to overcome this limitation. By one method, a "helper" nucleic acid sequence is introduced into the system, and this hybridizes with the DNAzyme components and releases the ligated product for opening of the hairpin. By the second method, a nicking enzyme (Nt.BspQI) is added to the system, and this nicks the duplex between the beacon and ligated product while recycling the free ligation product. By combining the two coadded components ("helper" sequence and nicking enzyme), the sensitive detection of the analyte is demonstrated (detection limit, 20 pM). The enzyme-free amplified fluorescence detection of the target DNA is further presented by the Zn(2+)-dependent ligation DNAzyme-driven activation of the Mg(2+)-dependent DNAzyme. According to this method, the Mg(2+)-dependent DNAzyme subunits displace the ligated product, and the resulting assembled DNAzyme cleaves a fluorophore/quencher-modified substrate to yield fluorescence. The method enabled the detection of the target DNA with a detection limit corresponding to 10 pM. The different sensing platforms are implemented to detect the Tay-Sachs genetic disorder mutant. PMID:22612395

  5. Preparation, characterization, non-isothermal reaction kinetics, thermodynamic properties, and safety performances of high nitrogen compound: Hydrazine 3-nitro-1,2,4-triazol-5-one complex

    International Nuclear Information System (INIS)

    A new high nitrogen compound hydrazine 3-nitro-1,2,4-triazol-5-one complex (HNTO) was prepared by the reaction of 3-nitro-1,2,4-triazol-5-one with hydrazine hydrate, and its structure was characterized by means of organic elemental analyzer, FT-IR, XRD, 13C NMR and 15N NMR. The non-isothermal reaction kinetics of the main exothermic decomposition reaction of HNTO was investigated by means of DSC. The thermodynamic properties of HNTO were calculated. The results showed that the formation of HNTO is achieved by proton transfer of N(4) atom, and it makes a higher nitrogen content and lower acidity. The reaction mechanism of HNTO is classified as nucleation and growth, and the mechanism function is Avramo-Erofeev equation with n = 2/5. The kinetic parameters of the reaction are Ea = 195.29 kJ mol-1, lg(A (s-1)) = 19.37, respectively. The kinetic equation can be expressed as: (dα)/(dt) =1018.97(1-α)[-ln(1-α)]3/5e-2.35x104/T The safety performances of HNTO were carried out. The critical temperature of thermal explosion are 464.26 and 474.37 K, the adiabatic time-to-explosion is 262 s, the impact sensitivity H50 = 45.7 cm, the friction sensitivity P = 20% and the electrostatic spark sensitivity E50 > 5.4 J (no ignition). It shows that HNTO has an insensitive nature as RDX and NTO, etc

  6. The Effect of Nitrogen Surface Ligands on Propane Metathesis: Design and Characterizations of N-modified SBA15-Supported Schrock-type Tungsten Alkylidyne

    KAUST Repository

    Eid, Ahmed A.

    2014-04-01

    Catalysis, which is primarily a molecular phenomenon, is an important field of chemistry because it requires the chemical conversion of molecules into other molecules. It also has an effect on many fields, including, but not limited to, industry, environment and life Science[1]. Surface Organometallic Chemistry is an effective methodology for Catalysis as it imports the concept and mechanism of organometallic chemistry, to surface science and heterogeneous catalysis. So, it bridges the gap between homogenous and heterogeneous catalysis[1]. The aim of the present research work is to study the effect of Nitrogen surface ligands on the activity of Alkane, Propane in particular, metathesis. Our approach is based on the preparation of selectively well-defined group (VI) transition metal complexes supported onto mesoporous materials, SBA15 and bearing amido and/or imido ligands. We choose nitrogen ligands because, according to the literature, they showed in some cases better catalytic properties in homogenous catalysis in comparison with their oxygen counterparts[2]. The first section covers the modification of a highly dehydroxylated SBA15 surface using a controlled ammonia treatment. These will result in the preparation of two kind of Nitrogen surface ligands: -\\tOne with vicinal silylamine/silanol, (≡SiNH2)(≡SiOH), noted [N,O]SBA15 and, -\\tAnother\\tone\\twith\\tvicinal\\tbis-silylamine moieties (≡SiNH2)2, noted [N,N]SBA15[3]. The second section covers the reaction of Schrock type Tungsten Carbyne [W(≡C- tBu)(CH2-tBu)3] with those N-surface ligands and their characterizations by FT-IR, multiple quantum solid state NMR (1H, 13C), elemental analysis and gas phase analysis. The third section covers the generation of the active site, tungsten hydride species. Their performance toward propane metathesis reaction using the dynamic reactor technique PID compared toward previous well-known catalysts supported on silica oxide or mesoporous materials[4]. A fairly good

  7. Binding-regulated click ligation for selective detection of proteins.

    Science.gov (United States)

    Cao, Ya; Han, Peng; Wang, Zhuxin; Chen, Weiwei; Shu, Yongqian; Xiang, Yang

    2016-04-15

    Herein, a binding-regulated click ligation (BRCL) strategy for endowing selective detection of proteins is developed with the incorporation of small-molecule ligand and clickable DNA probes. The fundamental principle underlying the strategy is the regulating capability of specific protein-ligand binding against the ligation between clickable DNA probes, which could efficiently combine the detection of particular protein with enormous DNA-based sensing technologies. In this work, the feasibly of the BRCL strategy is first verified through agarose gel electrophoresis and electrochemical impedance spectroscopy measurements, and then confirmed by transferring it to a nanomaterial-assisted fluorescence assay. Significantly, the BRCL strategy-based assay is able to respond to target protein with desirable selectivity, attributing to the specific recognition between small-molecule ligand and its target. Further experiments validate the general applicability of the sensing method by tailoring the ligand toward different proteins (i.e., avidin and folate receptor), and demonstrate its usability in complex biological samples. To our knowledge, this work pioneers the practice of click chemistry in probing specific small-molecule ligand-protein binding, and therefore may pave a new way for selective detection of proteins.

  8. Banding ligation versus beta-blockers as primary prophylaxis in esophageal varices

    DEFF Research Database (Denmark)

    Gluud, Lise L; Klingenberg, Sarah; Nikolova, Dimitrinka;

    2007-01-01

    To compare banding ligation versus beta-blockers as primary prophylaxis in patients with esophageal varices and no previous bleeding.......To compare banding ligation versus beta-blockers as primary prophylaxis in patients with esophageal varices and no previous bleeding....

  9. Synthesis and characterization of nitrogen-rich macrocyclic ligands and an investigation of their coordination chemistry with lanthanum(III).

    Science.gov (United States)

    Wilson, Justin J; Birnbaum, Eva R; Batista, Enrique R; Martin, Richard L; John, Kevin D

    2015-01-01

    Derivatives of the ligand 1,4,7,10-tetraazacyclododecane (cyclen) containing pendant N-heterocyclic donors were prepared. The heterocycles pyridine, pyridazine, pyrimidine, and pyrazine were conjugated to cyclen to give 1,4,7,10-tetrakis(pyridin-2-ylmethyl)-1,4,7,10-tetraazacyclododecane (L(py)), 1,4,7,10-tetrakis(3-pyridazylmethyl)-1,4,7,10-tetraazacyclododecane (L(pyd)), 1,4,7,10-tetrakis(4-pyrimidylmethyl)-1,4,7,10-tetraazacyclododecane (L(pyr)), and 1,4,7,10-tetrakis(2-pyrazinylmethyl)-1,4,7,10-tetraazacyclododecane (L(pz)), respectively. The coordination chemistry of these ligands was explored using the La(3+) ion. Accordingly, complexes of the general formula [La(L)(OTf)](OTf)2, where OTf = trifluoromethanesulfonate and L = L(py) (1), L(pyd) (2), L(pyr) (3), and L(pz) (4), were synthesized and characterized by NMR spectroscopy. Crystal structures of 1 and 2 were also determined by X-ray diffraction studies, which revealed 9-coordinate capped, twisted square-antiprismatic coordination geometries for the central La(3+) ion. The conformational dynamics of 1-4 in solution were investigated by variable-temperature NMR spectroscopy. Dynamic line-shape and Eyring analyses enabled the determination of the activation parameters for the interconversion of enantiomeric forms of the complexes. Unexpectedly, the different pendant N-heterocycles of 1-4 give rise to varying values for the enthalpies and entropies of activation for this process. Density functional theory calculations were carried out to investigate the mechanism of this enantiomeric interconversion. Computed activation parameters were consistent with those experimentally determined for 1 but differed somewhat from those of 2-4.

  10. Characterization and copper binding of humic and nonhumic organic matter isolated from the South Platte River: Evidence for the presence of nitrogenous binding site

    Science.gov (United States)

    Croue, J.-P.; Benedetti, M.F.; Violleau, D.; Leenheer, J.A.

    2003-01-01

    Humic substances typically constitute 40-60% of the dissolved organic matter (DOM) in surface waters. However, little information is available regarding the metal binding properties of the nonhumic hydrophilic portion of the DOM. In this study, humic and nonhumic DOM samples were isolated from the South Platte River (Colorado, DOC = 2.6 mg??L-1, SUVA254 = 2.4 L/mg??m) using a two-column array of XAD-8 and XAD-4 resins. The three major isolated fractions of DOM, which accounted for 57% of the bulk DOM, were characterized using a variety of analytical tools. Proton and copper binding properties were studied for each fraction. The main objective of this work was to compare the structural and chemical characteristics of the isolated fractions and test models describing DOM reactivity toward metal ions. The characterization work showed significant structural differences between the three isolated fractions of DOM. The hydrophobic acid fraction (i.e., humic substances isolated from the XAD-8 resin) gave the largest C/H, C/O, and C/N ratios and aromatic carbon content among the three isolated fractions. The transphilic acid (TPHA) fraction ("transphilic" meaning fraction of intermediate polarity isolated from the XAD-4 resin) was found to incorporate the highest proportion of polysaccharides, whereas the transphilic neutral (TPHN) fraction was almost entirely proteinaceous. The gradual increase of the charge with pH for the three DOM fractions is most likely caused by a large distribution of proton affinity constants for the carboxylic groups, as well as a second type of group more generally considered to be phenolic. In the case of the DOM fraction enriched in proteinaceous material (i.e., TPHN fraction), the results showed that the amino groups are reponsible for the charge reversal. For low copper concentrations, nitrogen-containing functional groups similar to those of amino acids are likely to be involved in complexation, in agreement with previously published data.

  11. Spectroscopic characterization of the plasma generated during the deposition of AlxGa1−xN films by pulsed laser co-ablation of Al and GaAs targets in electron cyclotron resonance nitrogen plasma

    International Nuclear Information System (INIS)

    A nitrogen–aluminum–gallium–arsenic plasma is formed by pulsed laser co-ablation of an Al target and a GaAs target in electron cyclotron resonance discharge-generated nitrogen plasma for AlxGa1−xN film deposition. The formed plasma was characterized by time-integrated and time-resolved optical emission spectroscopy measurements and the process of AlxGa1−xN deposition was discussed. The plasma contains excited species originally present in the working N2 gas and energetic species ablated from the targets, and its emission is abundant in the emission bands of diatomic nitrogen molecules and molecular ions and the emission lines of monoatomic aluminum, gallium, and arsenic atoms and atomic ions. The temporal and spatial features of the plasma emission reveal that the nitrogen species in the electron cyclotron resonance nitrogen plasma experience additional excitations due to the expanding ablation plumes, and the ablated species are excited frequently when traveling with the expanding plumes in the nitrogen plasma, making the formed plasma very reactive, which is very important in the process of AlxGa1−xN film deposition. The deposited film was evaluated for composition analysis by energy-dispersive x-ray spectroscopy and structure characterization by x-ray diffraction. The AlxGa1−xN film is slightly nitrogen rich with an aluminum content x of about 0.6 and featured with hexagonal wurtzite crystal structure with preferred c-axis orientation. (paper)

  12. Detection of Protein SUMOylation In Situ by Proximity Ligation Assays.

    Science.gov (United States)

    Sahin, Umut; Jollivet, Florence; Berthier, Caroline; de Thé, Hugues; Lallemand-Breitenbach, Valérie

    2016-01-01

    Sumoylation is a posttranslational process essential for life and concerns a growing number of crucial proteins. Understanding the influence of this phenomenon on individual proteins or on cellular pathways in which they function has become an intense area of research. A critical step in studying protein sumoylation is to detect sumoylated forms of a particular protein. This has proven to be a challenging task for a number of reasons, especially in the case of endogenous proteins and in vivo studies or when studying rare cells such as stem cells. Proximity ligation assays that allow detection of closely interacting protein partners can be adapted for initial detection of endogenous sumoylation or ubiquitination in a rapid, ultrasensitive, and cheap manner. In addition, modified forms of a given protein can be detected in situ in various cellular compartments. Finally, the flexibility of this technique may allow rapid screening of drugs and stress signals that may modulate protein sumoylation. PMID:27631803

  13. In vivo multiphoton imaging of bile duct ligation

    Science.gov (United States)

    Liu, Yuan; Li, Feng-Chieh; Chen, Hsiao-Chin; Chang, Po-shou; Yang, Shu-Mei; Lee, Hsuan-Shu; Dong, Chen-Yuan

    2008-02-01

    Bile is the exocrine secretion of liver and synthesized by hepatocytes. It is drained into duodenum for the function of digestion or drained into gallbladder for of storage. Bile duct obstruction is a blockage in the tubes that carry bile to the gallbladder and small intestine. However, Bile duct ligation results in the changes of bile acids in serum, liver, urine, and feces1, 2. In this work, we demonstrate a novel technique to image this pathological condition by using a newly developed in vivo imaging system, which includes multiphoton microscopy and intravital hepatic imaging chamber. The images we acquired demonstrate the uptake, processing of 6-CFDA in hepatocytes and excretion of CF in the bile canaliculi. In addition to imaging, we can also measure kinetics of the green fluorescence intensity.

  14. A ligation-independent cloning method using nicking DNA endonuclease.

    Science.gov (United States)

    Yang, Jie; Zhang, Zhihong; Zhang, Xin A; Luo, Qingming

    2010-11-01

    Using nicking DNA endonuclease (NiDE), we developed a novel technique to clone DNA fragments into plasmids. We created a NiDE cassette consisting of two inverted NiDE substrate sites sandwiching an asymmetric four-base sequence, and NiDE cleavage resulted in 14-base single-stranded termini at both ends of the vector and insert. This method can therefore be used as a ligation-independent cloning strategy to generate recombinant constructs rapidly. In addition, we designed and constructed a simple and specific vector from an Escherichia coli plasmid back-bone to complement this cloning method. By cloning cDNAs into this modified vector, we confirmed the predicted feasibility and applicability of this cloning method. PMID:21091446

  15. MANAGEMENT OF INTERNAL HEMORRHOID WITH RUBBER BAND LIGATION PROCEDURE

    Directory of Open Access Journals (Sweden)

    I Made Arya Winangun

    2013-10-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Hemorrhoid is regarded as the cases most seen in population. The prevalence of this cases about 4,4% with the incidence 12 of 1.000 patient. The current management of hemorrhoid is lifestyle modification, conservative management such as farmacology, minimally invasive treatment and more aggressive therapy using surgical procedure. Rubber band ligation was one of the minimally invasive procedures. This procedure was easy, inexpensive, and can be done outpatient using simple tools without complicated procedure like hemorrhoidectomy. Some studies explained rubber band ligation effectively done in internal hemorrhoid grade II and grade III even this procedure still had minimal complication such as bleeding and unpleasentness /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  16. TG-FTIR characterization of coal and biomass single fuels and blends under slow heating rate conditions: Partitioning of the fuel-bound nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Di Nola, G.; de Jong, W.; Spliethoff, H. [Energy Technology Section, Process and Energy Department, Faculty 3me, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft (Netherlands)

    2010-01-15

    The devolatilization behavior of a bituminous coal and different biomass fuels currently applied in the Dutch power sector for co-firing was experimentally investigated. The volatile composition during single fuel pyrolysis as well as during co-pyrolysis was studied using TG-FTIR characterization with the focus on the release patterns and quantitative analysis of the gaseous bound nitrogen species. It was shown that all investigated biomass fuels present more or less similar pyrolysis behavior, with a maximum weight loss between 300 and 380 C. Woody and agricultural biomass materials show higher devolatilization rates than animal waste. When comparing different fuels, the percentage of fuel-bound nitrogen converted to volatile bound-N species (NH{sub 3}, HCN, HNCO) does not correlate with the initial fuel-N content. Biomass pyrolysis resulted in higher volatile-N yields than coal, which potentially indicates that NO{sub x} control during co-firing might be favored. No significant interactions occurred during the pyrolysis of coal/biomass blends at conditions typical of TG analysis (slow heating rate). Evolved gas analysis of volatile species confirmed the absence of mutual interactions during woody biomass co-pyrolysis. However, non-additive behavior of selected gas species was found during slaughter and poultry litter co-pyrolysis. Higher CH{sub 4} yields between 450 and 750 C and higher ammonia and CO yields between 550 and 900 C were measured. Such a result is likely to be attributed to catalytic effects of alkali and alkaline earth metals present in high quantity in animal waste ash. The fact that the co-pyrolysis of woody and agricultural biomass is well modeled by simple addition of the individual behavior of its components permits to predict the mixture's behavior based on experimental data available for single fuels. On the other hand, animal waste co-pyrolysis presented in some cases synergistic effects in gas products although additive behavior

  17. Protein synthesis by native chemical ligation: expanded scope by using straightforward methodology.

    Science.gov (United States)

    Hackeng, T M; Griffin, J H; Dawson, P E

    1999-08-31

    The total chemical synthesis of proteins has great potential for increasing our understanding of the molecular basis of protein function. The introduction of native chemical ligation techniques to join unprotected peptides next to a cysteine residue has greatly facilitated the synthesis of proteins of moderate size. Here, we describe a straightforward methodology that has enabled us to rapidly analyze the compatibility of the native chemical ligation strategy for X-Cys ligation sites, where X is any of the 20 naturally occurring amino acids. The simplified methodology avoids the necessity of specific amino acid thioester linkers or alkylation of C-terminal thioacid peptides. Experiments using matrix-assisted laser-desorption ionization MS analysis of combinatorial ligations of LYRAX-C-terminal thioester peptides to the peptide CRANK show that all 20 amino acids are suitable for ligation, with Val, Ile, and Pro representing less favorable choices because of slow ligation rates. To illustrate the method's utility, two 124-aa proteins were manually synthesized by using a three-step, four-piece ligation to yield a fully active human secretory phospholipase A(2) and a catalytically inactive analog. The combination of flexibility in design with general access because of simplified methodology broadens the applicability and versatility of chemical protein synthesis. PMID:10468563

  18. Microbial characterization of nitrification in a shallow, nitrogen-contaminated aquifer, Cape Cod, Massachusetts and detection of a novel cluster associated with nitrifying Betaproteobacteria

    Science.gov (United States)

    Miller, D.N.; Smith, R.L.

    2009-01-01

    Groundwater nitrification is a poorly characterized process affecting the speciation and transport of nitrogen. Cores from two sites in a plume of contamination were examined using culture-based and molecular techniques targeting nitrification processes. The first site, located beneath a sewage effluent infiltration bed, received treated effluent containing O2 (> 300????M) and NH4+ (51-800????M). The second site was 2.5??km down-gradient near the leading edge of the ammonium zone within the contaminant plume and featured vertical gradients of O2, NH4+, and NO3- (0-300, 0-500, and 100-200????M with depth, respectively). Ammonia- and nitrite-oxidizers enumerated by the culture-based MPN method were low in abundance at both sites (1.8 to 350??g- 1 and 33 to 35,000??g- 1, respectively). Potential nitrifying activity measured in core material in the laboratory was also very low, requiring several weeks for products to accumulate. Molecular analysis of aquifer DNA (nested PCR followed by cloning and 16S rDNA sequencing) detected primarily sequences associated with the Nitrosospira genus throughout the cores at the down-gradient site and a smaller proportion from the Nitrosomonas genus in the deeper anoxic, NH4+ zone at the down-gradient site. Only a single Nitrosospira sequence was detected beneath the infiltration bed. Furthermore, the majority of Nitrosospira-associated sequences represent an unrecognized cluster. We conclude that an uncharacterized group associated with Nitrosospira dominate at the geochemically stable, down-gradient site, but found little evidence for Betaproteobacteria nitrifiers beneath the infiltration beds where geochemical conditions were more variable.

  19. Synthesis, characterization and biological relevance of some metal (II) complexes with oxygen, nitrogen and oxygen (ONO) donor Schiff base ligand derived from thiazole and 2-hydroxy-1-naphthaldehyde

    Science.gov (United States)

    Nagesh, G. Y.; Mruthyunjayaswamy, B. H. M.

    2015-04-01

    The novel Schiff base ligand 2-((2-hydroxynaphthalen-1-yl)methylene)-N-(4-phenylthiazol-2-yl)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 2-hydroxy-1-naphthaldehyde and its newly synthesized Cu(II), Co(II), Ni(II), Zn(II) and Cd(II) complexes have been characterized by microanalysis, molar conductance, IR, 1H NMR, ESI-mass, UV-Visible, TGA/DTA, ESR and powder X-ray diffraction data to explicate their structures. The IR results confirmed the tridentate binding of the ligand involving oxygen atom of amide carbonyl, azomethine nitrogen and naphthol oxygen. 1H NMR spectral data of the ligand (L) and its Zn(II) complex agreed well with the proposed structures. Thermogravimetric studies for Cu(II) and Ni(II) complexes indicated the presence of coordinated water molecules and the final product is the metal oxide. In order to appraise the effect of antimicrobial activity of metal ions upon chelation, the newly synthesized ligand and its metal complexes were screened for their antimicrobial activity by minimum inhibitory concentration (MIC) method. The DNA cleavage activities were studied using plasmid DNA pBR322 (Bangal re Genei, Bengaluru, Cat. No 105850) as a target molecule by agarose gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties against Artemia salina. Furthermore, the antioxidant activity were determined in vitro by reduction of 1,1-diphenyl-2-picryl hydrazyl (DPPH). The ligand exhibited better in vitro-antioxidant activity than its metal complexes.

  20. Differences in bleeding behavior after endoscopic band ligation: a retrospective analysis

    Directory of Open Access Journals (Sweden)

    Schiefke Ingolf

    2010-01-01

    Full Text Available Abstract Background Endoscopic band ligation (EBL is generally accepted as the treatment of choice for bleeding from esophageal varices. It is also used for secondary prophylaxis of esophageal variceal hemorrhage. However, there is no data or guidelines concerning endoscopic control of ligation ulcers. We conducted a retrospective study of EBL procedures analyzing bleeding complications after EBL. Methods We retrospectively analyzed data from patients who underwent EBL. We analyzed several data points, including indication for the procedure, bleeding events and the time interval between EBL and bleeding. Results 255 patients and 387 ligation sessions were included in the analysis. We observed an overall bleeding rate after EBL of 7.8%. Bleeding events after elective treatment (3.9% were significantly lower than those after treatment for acute variceal hemorrhage (12.1%. The number of bleeding events from ligation ulcers and variceal rebleeding was 14 and 15, respectively. The bleeding rate from the ligation site in the group who underwent emergency ligation was 7.1% and 0.5% in the group who underwent elective ligation. Incidence of variceal rebleeding did not vary significantly. Seventy-five percent of all bleeding episodes after elective treatment occurred within four days after EBL. 20/22 of bleeding events after emergency ligation occured within 11 days after treatment. Elective EBL has a lower risk of bleeding from treatment-induced ulceration than emergency ligation. Conclusions Patients who underwent EBL for treatment of acute variceal bleeding should be kept under medical surveillance for 11 days. After elective EBL, it may be reasonable to restrict the period of surveillance to four days or even perform the procedure in an out-patient setting.

  1. Comparative Study of Compensatory Liver Regeneration in a Rat Model: Portal Vein Ligation Only versus Sequential Ligation of the Portal Vein and Hepatic Artery

    International Nuclear Information System (INIS)

    To compare the volume change and the regenerative capacity between portal vein ligation (embolization) (PVL) and heterochronous PVL with hepatic artery ligation (HAL) in a rodent model. The animals were separated into three groups: group I, ligation of the left lateral and median portal vein branches; group II, completion of PVL, followed by ligation of the same branches of the hepatic artery after 48 h; control group, laparotomy without ligation was performed. Five rats from each group were sacrificed on 1, 3, 5, and 7 days after the operation. Volume change measurement, liver function tests and immunohistochemical analysis were performed. The volume of the nonligated lobe between groups I and II was not significantly different by day 5 and day 7. Mean alanine aminotransferase and total bilirubin levels were significantly higher in group II, while the albumin level was higher in group I. Both c-kit- and MIB-5-positive cells used in the activity detection of regeneration were more prevalent in group I on day 1, 3, and 5, with statistical significance. There was no operation related mortality. PVL alone is safe and effective in compensatory liver regeneration. Performing both PVL and HAL does not confer any additional benefits.

  2. Effect of portal vein ligation on tumor growth and liver regeneration in rat cirrhotic liver lobes

    OpenAIRE

    Xu, Rui; YUAN, YU-FENG; Ayav, Ahmet; JIANG, CHONG-QING; BRESLER, LAURENT; Liu, Zhi-Su; Tran, Nguyen

    2014-01-01

    The aim of the present study was to investigate the effect of portal vein ligation (PVL) on the tumor growth rate and liver regeneration in rat cirrhotic liver lobes. A total of 45 male Wistar rats were randomly divided into PVL, hepatic tumor (HT) and HT + PVL groups (n=15 per group). Liver regeneration and tumor growth in ligated and non-ligated lobes were evaluated prior to and following PVL. In addition, serum alanine transaminase, total bilirubin levels and liver tissue samples were eval...

  3. Nitrogen species

    Science.gov (United States)

    Harries, J. E.; Brasseur, G.; Coffey, M. T.; Fischer, H.; Gille, J.; Jones, R.; Louisnard, N.; McCormick, M. P.; Noxon, J.; Owens, A. J.

    Total odd nitrogen, NO(y), may be defined as the sum of all active nitrogen species that interchange photochemically with one another on a time scale of the order of weeks or less. As noted, NO + NO2 reactions dominate the processes controlling the ozone balance in the contemporary stratosphere. The observational data from non-satellite platforms are reviewed. The growth in available satellite data in the past four years is considered. Some of the most important scientific issues are discussed, taking into account new results from atmospheric models (mainly 2-D). The model results are compared with the observational data.

  4. Nitrogen retention in ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Meisl, G., E-mail: gmeisl@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching (Germany); Physik-Department E28, Technische Universität München, 85747 Garching (Germany); Schmid, K.; Oberkofler, M.; Krieger, K. [Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching (Germany); Lisgo, S.W. [ITER Organization, FST, Route de Vinon, CS 90 046, 13067 Saint Paul Lez Durance Cedex (France); Aho-Mantila, L. [VTT, FI-02044 VTT (Finland); Reimold, F. [Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching (Germany)

    2015-08-15

    We investigated the transport of nitrogen through the plasma and the interaction of nitrogen with tungsten under divertor exposure conditions during nitrogen-seeding experiments in ASDEX Upgrade. Using the divertor manipulator system, tungsten samples were exposed to well-characterized L-mode plasmas with and without nitrogen seeding. We also simulated nitrogen transport and re-distribution in these discharges by self-consistent WallDYN–DIVIMP modeling. For these simulations we applied a W–N surface model based on laboratory experiments and plasma backgrounds from SOLPS. In contrast to the conclusion from Kallenbach and Dux (2010) [5] we find that the N retention in ASDEX Upgrade is in agreement with results from laboratory experiments.

  5. Heated oligonucleotide ligation assay (HOLA): an affordable single nucleotide polymorphism assay.

    Science.gov (United States)

    Black, W C; Gorrochotegui-Escalante, N; Duteau, N M

    2006-03-01

    Most single nucleotide polymorphism (SNP) detection requires expensive equipment and reagents. The oligonucleotide ligation assay (OLA) is an inexpensive SNP assay that detects ligation between a biotinylated "allele-specific detector" and a 3' fluorescein-labeled "reporter" oligonucleotide. No ligation occurs unless the 3' detector nucleotide is complementary to the SNP nucleotide. The original OLA used chemical denaturation and neutralization. Heated OLA (HOLA) instead uses a thermal stable ligase and cycles of denaturing and hybridization for ligation and SNP detection. The cost per genotype is approximately US$1.25 with two-allele SNPs or approximately US$1.75 with three-allele SNPs. We illustrate the development of HOLA for SNP detection in the Early Trypsin and Abundant Trypsin loci in the mosquito Aedes aegypti (L.) and at the a-glycerophosphate dehydrogenase locus in the mosquito Anopheles gambiae s.s.

  6. Native Chemical Ligation to Minimize Aspartimide Formation during Chemical Synthesis of Small LDLa Protein.

    Science.gov (United States)

    Tailhades, Julien; Sethi, Ashish; Petrie, Emma J; Gooley, Paul R; Bathgate, Ross A; Wade, John D; Hossain, Mohammed A

    2016-01-18

    The inhibition of the G protein-coupled receptor, relaxin family peptide receptor 1 (RXFP1), by a small LDLa protein may be a potential approach for prostate cancer treatment. However, it is a significant challenge to chemically produce the 41-residue and three-disulfide cross-bridged LDLa module which is highly prone to aspartimide formation due to the presence of several aspartic acid residues. Known palliative measures, including addition of HOBt to piperidine for N(α) -deprotection, failed to completely overcome this side reaction. For this reason, an elegant native chemical ligation approach was employed in which two segments were assembled for generating the linear LDLa protein. Acquisition of correct folding was achieved by using either a regioselective disulfide bond formation or global oxidation strategies. The final synthetic LDLa protein obtained was characterized by NMR spectroscopic structural analysis after chelation with a Ca(2+) ion and confirmed to be equivalent to the same protein obtained by recombinant DNA production. PMID:26612092

  7. Divergent and convergent synthesis of GalNAc-conjugated dendrimers using dual orthogonal ligations.

    Science.gov (United States)

    Thomas, Baptiste; Pifferi, Carlo; Daskhan, Gour Chand; Fiore, Michele; Berthet, Nathalie; Renaudet, Olivier

    2015-12-21

    The synthesis of glycodendrimers remains a challenging task. In this paper we propose a protocol based on both oxime ligation (OL) to combine cyclopeptide repeating units as the dendritic core and the copper(i)-catalyzed azide-alkyne cycloaddition (CuAAC) to conjugate peripheral α and β propargylated GalNAc. By contrast with the oxime-based iterative protocol reported in our group, our current strategy can be used in both divergent and convergent routes with similar efficiency and the resulting hexadecavalent glycodendrimers can be easily characterized compared to oxime-linked analogues. A series of glycoconjugates displaying four or sixteen copies of both α and β GalNAc have been prepared and their ability to inhibit the adhesion of the soybean agglutinin (SBA) lectin to polymeric-GalNAc immobilized on microtiter plates has been evaluated. As was anticipated, the higher inhibitory effect (IC50 = 0.46 μM) was measured with the structure displaying αGalNAc with the higher valency (compound 13), which demonstrates that the binding properties of these glycoconjugates are strongly dependent on the orientation and distribution of the GalNAc units.

  8. Comparison of frictional resistance of esthetic and semi-esthetic self-ligating brackets

    Science.gov (United States)

    Kannan, M. S.; Murali, R. V.; Kishorekumar, S.; Gnanashanmugam, K.; Jayanth, V.

    2015-01-01

    Aim: The frictional resistance encountered during sliding mechanics has been well established in the orthodontic literature, and it consists of complex interactions between the bracket, archwire, and method of ligation the claim of reduced friction with self-ligating brackets is often cited as a primary advantage over conventional brackets. This study was done to compare and evaluate the frictional forces generated between fully esthetic brackets and semi-aesthetic self-ligating brackets, which are of passive form and SEM (scanning electron microscope) study of the Brackets after Frictional evaluation. Materials and Methods: Two types of self-ligating esthetic brackets, Damon clear (Ormco) made of fully ceramic and Opal (Ultradent Products, USA) and, Two types of self-ligating semi-esthetic brackets, Clarity SL (3M Unitek) and Damon 3 (Ormco) both of which are made of ceramic with metal slot. Arch wires with different dimensions and quality 17 × 25, 19 × 25 Titanium Molybdenum Alloy (TMA) and 17 × 25, 19 × 25 stainless steel that came from plain strands of wire were used for frictional comparison test. The brackets used in this study had 0.022 × 0.028 inch slot. Results: The statistical tests showed significantly smaller amount of kinetic frictional forces is generated by Damon 3 (semi-esthetic self-ligating brackets). For each wire used, Damon 3 displayed significantly lower frictional forces (P ≤ 0.05) than any of the self-ligating system, followed by Opal (fully esthetic self-ligating brackets) which generated smaller amount of frictional forces but relatively on the higher side when compared with Damon 3. Damon clear (fully esthetic self-ligating brackets) generated the maximum amount of kinetic forces with all types of wire dimensions and properties when compared to the other three types of self-ligating system. Clarity SL (semi-esthetic self-ligating brackets) generated smaller amount of frictional forces when compared with Damon clear and relatively

  9. Comparison of frictional resistance of esthetic and semi-esthetic self-ligating brackets

    Directory of Open Access Journals (Sweden)

    M S Kannan

    2015-01-01

    Full Text Available Aim: The frictional resistance encountered during sliding mechanics has been well established in the orthodontic literature, and it consists of complex interactions between the bracket, archwire, and method of ligation the claim of reduced friction with self-ligating brackets is often cited as a primary advantage over conventional brackets. This study was done to compare and evaluate the frictional forces generated between fully esthetic brackets and semi-aesthetic self-ligating brackets, which are of passive form and SEM (scanning electron microscope study of the Brackets after Frictional evaluation. Materials and Methods: Two types of self-ligating esthetic brackets, Damon clear (Ormco made of fully ceramic and Opal (Ultradent Products, USA and, Two types of self-ligating semi-esthetic brackets, Clarity SL (3M Unitek and Damon 3 (Ormco both of which are made of ceramic with metal slot. Arch wires with different dimensions and quality 17 × 25, 19 × 25 Titanium Molybdenum Alloy (TMA and 17 × 25, 19 × 25 stainless steel that came from plain strands of wire were used for frictional comparison test. The brackets used in this study had 0.022 × 0.028 inch slot. Results: The statistical tests showed significantly smaller amount of kinetic frictional forces is generated by Damon 3 (semi-esthetic self-ligating brackets. For each wire used, Damon 3 displayed significantly lower frictional forces (P ≤ 0.05 than any of the self-ligating system, followed by Opal (fully esthetic self-ligating brackets which generated smaller amount of frictional forces but relatively on the higher side when compared with Damon 3. Damon clear (fully esthetic self-ligating brackets generated the maximum amount of kinetic forces with all types of wire dimensions and properties when compared to the other three types of self-ligating system. Clarity SL (semi-esthetic self-ligating brackets generated smaller amount of frictional forces when compared with Damon clear and

  10. Cross-catalytic peptide nucleic acid (PNA) replication based on templated ligation

    DEFF Research Database (Denmark)

    Singhal, Abhishek; Nielsen, Peter E

    2014-01-01

    We report the first PNA self-replicating system based on template directed cross-catalytic ligation, a process analogous to biological replication. Using two template PNAs and four pentameric precursor PNAs, all four possible carbodiimide assisted amide ligation products were detected and identif...... oligonucleotides are feasible, thereby strengthening the foundation for the discussion of a possible role for PNA (like) genetic material in the prebiotic evolution of life and lay the ground for further studies into evolution of such potentially prebiotic systems....

  11. GASTROPROTECTIVE EFFECTS OF FRUITS OF TRIBULUS TERRESTRIS L. IN PYLORUS-LIGATED WISTAR RAT MODEL

    OpenAIRE

    Sanjay Jain*, Rakesh Barik, Nidhi Yadav and Shivpal Singh

    2013-01-01

    Tribulus terrestris L. (TT; Zygophyllaceae) is employed in the folk medicine against sexual impotence, oedemas, abdominal distention and cardiovascular diseases. Gastroprotective (i.e. antiulcer and anti-secretory) potential of methanolic extract of TT fruits was evaluated in pylorus-ligated rat model of Wistar rat. The methanolic extract of TT was tested orally at the doses of 150, 300 & 600 mg/kg, on gastric ulcerations experimentally induced by pylorus ligation. Preliminary phytochemical s...

  12. Ligation of RNA Oligomers by the Schistosoma mansoni Hammerhead Ribozyme in Frozen Solution.

    Science.gov (United States)

    Lie, Lively; Biliya, Shweta; Vannberg, Fredrik; Wartell, Roger M

    2016-03-01

    The interstitial liquid phase within frozen aqueous solutions is an environment that minimizes RNA degradation and facilitates reactions that may have relevance to the RNA World hypothesis. Previous work has shown that frozen solutions support condensation of activated nucleotides into RNA oligomers, RNA ligation by the hairpin ribozyme, and RNA synthesis by a RNA polymerase ribozyme. In the current study, we examined the activity of a hammerhead ribozyme (HHR) in frozen solution. The Schistosoma mansoni hammerhead ribozyme, which predominantly cleaves RNA, can ligate its cleaved products (P1 and P2) with yields up to ~23 % in single turnover experiments at 25 °C in the presence of Mg(2+). Our studies show that this HHR ligates RNA oligomers in frozen solution in the absence of divalent cations. Citrate and other anions that exhibit strong ion-water affinity enhanced ligation. Yields up to 43 % were observed in one freeze-thaw cycle and a maximum of 60 % was obtained after several freeze-thaw cycles using wild-type P1 and P2. Truncated and mutated P1 substrates were ligated to P2 with yields of 14-24 % in one freeze-thaw cycle. A pool of P2 substrates with mixtures of all four bases at five positions were ligated with P1 in frozen solution. High-throughput sequencing indicated that 70 of the 1024 possible P2 sequences were represented in ligated products at 1000 or more read counts per million reads. The results indicate that the HHR can ligate a range of short RNA oligomers into an ensemble of diverse sequences in ice.

  13. Outcome following patent ductus arteriosus ligation in premature infants: a retrospective cohort analysis

    Directory of Open Access Journals (Sweden)

    Yates Robert

    2006-05-01

    Full Text Available Abstract Background The patent ductus arteriosus (PDA is an important problem in premature infants. Surgical PDA ligation is usually only be considered when medical treatment has either failed or was contraindicated. The aims of our study were to determine the mortality and morbidity following patent ductus arteriosus ligation in premature infants, and whether prostaglandin synthetase inhibitor (PSI use prior to ligation affects outcome. Methods A retrospective case note review study to determine the outcome of premature infants undergoing patent ductus arteriosus ligation in one tertiary neonatal intensive care unit and two paediatric cardiothoracic centres. Results We had follow-up data on 87 infants. Cumulative mortality rates at 7 days, 30 days and at hospital discharge were 2%, 8% and 20% respectively. The incidence of chronic lung disease, intraventricular haemorrhage, necrotising enterocolitis and retinopathy of prematurity were 77%, 39%, 26% and 28% respectively. There was no difference in mortality, incidence of chronic lung disease or duration of oxygen dependence between those who had and those who had not received a PSI prior to surgical ligation. In those who had received 2 or more courses of PSI prior to surgical ligation, there was a trend to increase in the duration of oxygen therapy and chronic lung disease, but no difference in mortality. Conclusion This study shows that patent ductus arteriosus ligation is a relatively safe procedure (30 day survival 92% but there is substantial late mortality and a high incidence of morbidity in the survivors. 2 or more courses of PSI prior to surgical ligation trends to increased oxygen dependence and chronic lung disease. This high risk population requires careful follow-up. A definitive prospective cohort study is lacking.

  14. Meta-analysis: banding ligation and medical interventions for the prevention of rebleeding from oesophageal varices

    DEFF Research Database (Denmark)

    Thiele, Maja; Krag, A; Rohde, Ulrich;

    2012-01-01

    In patients with oesophageal varices, the combination of endoscopic variceal ligation (EVL) and medical therapy is recommended as standard of care for prevention of rebleeding. The results of previous meta-analyses on this topic are equivocal.......In patients with oesophageal varices, the combination of endoscopic variceal ligation (EVL) and medical therapy is recommended as standard of care for prevention of rebleeding. The results of previous meta-analyses on this topic are equivocal....

  15. Tubal ligation and salpingectomy and the risk of epithelial ovarian cancer and borderline ovarian tumors

    DEFF Research Database (Denmark)

    Madsen, C; Baandrup, Louise; Dehlendorff, Christian;

    2015-01-01

    OBJECTIVE: According to the recent theories on the ovarian cancer origin, any protective effect of tubal ligation may vary with histologic subtype of ovarian cancer. Furthermore, bilateral salpingectomy may represent an opportunity for surgical prevention of serous ovarian cancer. DESIGN: Nationw......OBJECTIVE: According to the recent theories on the ovarian cancer origin, any protective effect of tubal ligation may vary with histologic subtype of ovarian cancer. Furthermore, bilateral salpingectomy may represent an opportunity for surgical prevention of serous ovarian cancer. DESIGN...

  16. Cholestasis progression effects on long-term memory in bile duct ligation rats

    Directory of Open Access Journals (Sweden)

    Nasrin Hosseini

    2014-01-01

    Full Text Available Background : There is evidence that cognitive functions are affected by some liver diseases such as cholestasis. Bile duct ligation induces cholestasis as a result of impaired liver function and cognition. This research investigates the effect of cholestasis progression on memory function in bile duct ligation rats. Materials and Methods: Male Wistar rats were randomly divided into five groups, which include: control group for BDL-7, control group for BDL-21, sham group (underwent laparotomy without bile duct ligation, BDL-7 group (7 days after bile duct ligation, and BDL-21 group (21 days after bile duct ligation. Step-through passive avoidance test was employed to examine memory function. In all groups, short-term (7 days after foot shock and long-term memories (21 days after foot shock were assessed. Results: Our results showed that liver function significantly decreased with cholestasis progression (P < 0.01. Also our findings indicated BDL-21 significantly impaired acquisition time (P < 0.05. Memory retrieval impaired 7 (P < 0.05 and 21 days (P < 0.001 after foot shock in BDL-7 and BDL-21 groups, respectively. Conclusion: Based on these findings, liver function altered in cholestasis and memory (short-term and long-term memory impaired with cholestasis progression in bile duct ligation rats. Further studies are needed to better insight the nature of progression of brain damage in cholestatic disease.

  17. Realizing Serine/Threonine Ligation: Scope and Limitations and Mechanistic Implication Thereof

    Directory of Open Access Journals (Sweden)

    Clarence T. T. Wong

    2014-05-01

    Full Text Available Serine/Threonine ligation (STL has emerged as an alternative tool for protein chemical synthesis, bioconjugations as well as macrocyclization of peptides of various sizes. Owning to the high abundance of Ser/Thr residues in natural peptides and proteins, STL is expected to find a wide range of applications in chemical biology research. Herein, we have fully investigated the compatibility of the serine/threonine ligation strategy for X-Ser/Thr ligation sites, where X is any of the 20 naturally occurring amino acids. Our studies have shown that 17 amino acids are suitable for ligation, while Asp, Glu, and Lys are not compatible. Among the working 17 C-terminal amino acids, the retarded reaction resulted from the bulky β-branched amino acid (Thr, Val and Ile is not seen under the current ligation condition. We have also investigated the chemoselectivity involving the amino group of the internal lysine which may compete with the N-terminal Ser/Thr for reaction with the C-terminal salicylaldehyde (SAL ester aldehyde group. The result suggested that the free internal amino group does not adversely slow down the ligation rate.

  18. Treatment of glioblastoma multiforme cells with temozolomide-BioShuttle ligated by the inverse Diels-Alder ligation chemistry

    Science.gov (United States)

    Braun, Klaus; Wiessler, Manfred; Ehemann, Volker; Pipkorn, Ruediger; Spring, Herbert; Debus, Juergen; Didinger, Bernd; Koch, Mario; Muller, Gabriele; Waldeck, Waldemar

    2008-01-01

    Recurrent glioblastoma multiforme (GBM), insensitive against most therapeutic interventions, has low response and survival rates. Temozolomide (TMZ) was approved for second-line therapy of recurrent anaplastic astrocytoma. However, TMZ therapy in GBM patients reveals properties such as reduced tolerability and inauspicious hemogram. The solution addressed here concerning GBM therapy consolidates and uses the potential of organic and peptide chemistry with molecular medicine. We enhanced the pharmacologic potency with simultaneous reduction of unwanted adverse reactions of the highly efficient chemotherapeutic TMZ. The TMZ connection to transporter molecules (TMZ-BioShuttle) was investigated, resulting in a much higher pharmacological effect in glioma cell lines and also with reduced dose rate. From this result we can conclude that a suitable chemistry could realize the ligation of pharmacologically active, but sensitive and highly unstable pharmaceutical ingredients without functional deprivation. The TMZ-BioShuttle dramatically enhanced the potential of TMZ for the treatment of brain tumors and is an attractive drug for combination chemotherapy. PMID:19920915

  19. Permanent ligation of the left anterior descending coronary artery in mice: a model of post-myocardial infarction remodelling and heart failure.

    Science.gov (United States)

    Muthuramu, Ilayaraja; Lox, Marleen; Jacobs, Frank; De Geest, Bart

    2014-12-02

    Heart failure is a syndrome in which the heart fails to pump blood at a rate commensurate with cellular oxygen requirements at rest or during stress. It is characterized by fluid retention, shortness of breath, and fatigue, in particular on exertion. Heart failure is a growing public health problem, the leading cause of hospitalization, and a major cause of mortality. Ischemic heart disease is the main cause of heart failure. Ventricular remodelling refers to changes in structure, size, and shape of the left ventricle. This architectural remodelling of the left ventricle is induced by injury (e.g., myocardial infarction), by pressure overload (e.g., systemic arterial hypertension or aortic stenosis), or by volume overload. Since ventricular remodelling affects wall stress, it has a profound impact on cardiac function and on the development of heart failure. A model of permanent ligation of the left anterior descending coronary artery in mice is used to investigate ventricular remodelling and cardiac function post-myocardial infarction. This model is fundamentally different in terms of objectives and pathophysiological relevance compared to the model of transient ligation of the left anterior descending coronary artery. In this latter model of ischemia/reperfusion injury, the initial extent of the infarct may be modulated by factors that affect myocardial salvage following reperfusion. In contrast, the infarct area at 24 hr after permanent ligation of the left anterior descending coronary artery is fixed. Cardiac function in this model will be affected by 1) the process of infarct expansion, infarct healing, and scar formation; and 2) the concomitant development of left ventricular dilatation, cardiac hypertrophy, and ventricular remodelling. Besides the model of permanent ligation of the left anterior descending coronary artery, the technique of invasive hemodynamic measurements in mice is presented in detail.

  20. Endoscopic band ligation for bleeding lesions in the small bowel

    Institute of Scientific and Technical Information of China (English)

    Takashi; Ikeya; Naoki; Ishii; Yuto; Shimamura; Kaoru; Nakano; Mai; Ego; Kenji; Nakamura; Koichi; Takagi; Katsuyuki; Fukuda; Yoshiyuki; Fujita

    2014-01-01

    AIM: To investigate the safety and efficacy of endo-scopic band ligation(EBL) for bleeding lesions in the small bowel.METHODS: This is a retrospective study evaluating EBL in six consecutive patients(three males, three fe-males, 46-86 years of age) treated between May 2009 and February 2014: duodenal vascular ectasia; 1, je-junal bleeding diverticulum; 1, ileal Dieulafoy’s lesion; 1 and ileal bleeding diverticula; 3. The success of the initial hemostasis was evaluated, and patients were observed for early rebleeding(within 30 d after EBL), and complications such as perforation and abscess for-mation. Follow-up endoscopies were performed in four patients.RESULTS: Initial hemostasis was successfully achieved with EBL in all six patients. Eversion was not sufficient in four diverticular lesions. Early rebleeding occurred three days after EBL in one ileal diverticulum, and arepeat endoscopy revealed dislodgement of the O-band and ulcer formation at the banded site. This rebleeding was managed conservatively. Late rebleeding occurred in this case(13 and 21 mo after initial EBL), and re-EBL was performed. Follow-up endoscopies revealed scar formation and the disappearance of vascular lesions at the banded site in the case with a duodenal bleeding lesion, and unresolved ileal diverticula in three cases. Surgery or transarterial embolization was not required without any complications during the median follow-up period of 45(range, 2-83) mo.CONCLUSION: EBL is a safe and effective endoscopic treatment for hemostasis of bleeding lesions in the small bowel.

  1. Nitrogen tank

    CERN Multimedia

    2006-01-01

    Wanted The technical file about the pressure vessel RP-270 It concerns the Nitrogen tank, 60m3, 22 bars, built in 1979, and installed at Point-2 for the former L3 experiment. If you are in possession of this file, or have any files about an equivalent tank (probably between registered No. RP-260 and -272), please contact Marc Tavlet, the ALICE Glimos.

  2. Infrared spectra and electronic structure calculations for NN complexes with U, UN, and NUN in solid argon, neon, and nitrogen.

    Science.gov (United States)

    Andrews, Lester; Wang, Xuefeng; Gong, Yu; Kushto, Gary P; Vlaisavljevich, Bess; Gagliardi, Laura

    2014-07-17

    Reactions of laser-ablated U atoms with N2 molecules upon codeposition in excess argon or neon at 4 K gave intense NUN and weak UN absorptions. Annealing produced progressions of new absorptions for the UN2(N2)1,2,3,4,5 and UN(N2)1,2,3,4,5,6 complexes. The neon-to-argon matrix shift decreases with increasing NN ligation and therefore the number of noble gas atoms left in the primary coordination sphere around the NUN molecule. Small matrix shifts are observed when the secondary coordination layers around the primary UN2(N2)1,2,3,4,5 and UN(N2)1,2,3,4,5,6 complexes are changed from neon-to-argon to nitrogen. Electronic structure, energy, and frequency calculations provide support for the identification of these complexes and the characterization of the N≡U≡N and U≡N core molecules as terminal uranium nitrides. Codeposition of U with pure nitrogen produced the saturated U(NN)7 complex, which UV irradiation converted to the NUN(NN)5 complex with slightly lower frequencies than found in solid argon.

  3. Molecular and structural characterization of dissolved organic matter from the deep ocean by FTICR-MS, including hydrophilic nitrogenous organic molecules

    Science.gov (United States)

    Reemtsma, T.; These, A.; Linscheid, M.; Leenheer, J.; Spitzy, A.

    2008-01-01

    Dissolved organic matter isolated from the deep Atlantic Ocean and fractionated into a so-called hydrophobic (HPO) fraction and a very hydrophilic (HPI) fraction was analyzed for the first time by Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) to resolve the molecular species, to determine their exact masses, and to calculate their molecular formulas. The elemental composition of about 300 molecules was identified. Those in the HPO fraction (14C age of 5100 year) are very similar to much younger freshwater fulvic acids, but less aromatic and more oxygenated molecules are more frequent. This trend continues toward the HPI fraction and may indicate biotic and abiotic aging processes that this material experienced since its primary production thousands of years ago. In the HPI fraction series of nitrogenous molecules containing one, two, or three nitrogens were identified by FTICR-MS. Product ion spectra of the nitrogenous molecules suggest that the nitrogen atoms in these molecules are included in the (alicyclic) backbone of these molecules, possibly in reduced form. These mass spectrometric data suggest that a large set of stable fulvic acids is ubiquitous in all aquatic compartments. Although sources may differ, their actual composition and structure appears to be quite similar and largely independent from their source, because they are the remainder of intensive oxidative degradation processes. ?? 2008 American Chemical Society.

  4. Treatment of glioblastoma multiforme cells with temozolomide-BioShuttle ligated by the inverse Diels-Alder ligation chemistry

    Directory of Open Access Journals (Sweden)

    Klaus Braun

    2009-01-01

    Full Text Available Klaus Braun1, Manfred Wiessler1, Volker Ehemann2, Ruediger Pipkorn3, Herbert Spring4, Juergen Debus5, Bernd Didinger5, Mario Koch3, Gabriele Muller6, Waldemar Waldeck61German Cancer Research Center, Dept of Imaging and Radiooncology, Heidelberg, Germany; 2University of Heidelberg, Institute of Pathology, Heidelberg, Germany; 3German Cancer Research Center, Central Peptide Synthesis Unit, Heidelberg, Germany; 4German Cancer Research Center, Dept of Structural Analysis of Gene Structure and Function, Heidelberg, Germany; 5University of Heidelberg, Dept of Radiation Oncology, Heidelberg, Germany; 6German Cancer Research Center,Division of Biophysics of Macromolecules, Heidelberg, GermanyAbstract: Recurrent glioblastoma multiforme (GBM, insensitive against most therapeutic interventions, has low response and survival rates. Temozolomide (TMZ was approved for second-line therapy of recurrent anaplastic astrocytoma. However, TMZ therapy in GBM patients reveals properties such as reduced tolerability and inauspicious hemogram. The solution addressed here concerning GBM therapy consolidates and uses the potential of organic and peptide chemistry with molecular medicine. We enhanced the pharmacologic potency with simultaneous reduction of unwanted adverse reactions of the highly efficient chemotherapeutic TMZ. The TMZ connection to transporter molecules (TMZ-BioShuttle was investigated, resulting in a much higher pharmacological effect in glioma cell lines and also with reduced dose rate. From this result we can conclude that a suitable chemistry could realize the ligation of pharmacologically active, but sensitive and highly unstable pharmaceutical ingredients without functional deprivation. The TMZ-BioShuttle dramatically enhanced the potential of TMZ for the treatment of brain tumors and is an attractive drug for combination chemotherapy.Keywords: drug delivery, carrier molecules, facilitated transport, glioblastoma multiforme, temozolomide

  5. Multiple ligation of the proximal greater saphenous vein in the CHIVA treatment of primary varicose veins

    Directory of Open Access Journals (Sweden)

    Roberto Delfrate

    2014-06-01

    Full Text Available Saphenous femoral disconnection is the key point of most surgical techniques in the treatment of primary varicose vein surgery. The aim of this study is to compare and analyze different techniques for conservative saphenousfemoral ligation or disconnection. These techniques can be to perform mini invasive open surgery and are suitable for implementation of the conservative hemodynamic correction of venous insufficiency (CHIVA method. The aim was to present the follow-up by retrospective analysis of three different ligation-disconnection techniques of the proximal great saphenous vein (GSV according to the CHIVA method at the GSV end, i.e. between the very end of the GSV and the first arch tributary, according to the CHIVA method. The first thecnique consisted of a surgical division (crossotomy. The other two consisted of triple superposed ligation with No. 2 non-absorbable braided coated suture without division labeled TSFL (triple saphenous flush ligation and No. 0 polypropylenene ligation TPL (triple polypropylene ligation. The difference between TSFL and TPL was in the thickness and type of material of the thread, though both were non-absorbable. The follow up of 56 TPL procedures, 61 crossotomy procedures, and 82 TSFL procedures was analysed. The follow-up consisted of checking the sapheno-femoral junction occlusion with Duplex color ultra sound. The incidence rates of neovascularization (new vessels in the ligation or surgical disconnection site with saphenous-femoral reflux during the Valsalva maneuver were: 4.9% for the crossotomy group, 6.1% for the TSFL group and 37.5% for the TPL group. The data analysed show satisfactory results with both crossotomy and TSFL. Crossotomy has proven to be an effective technique for performing saphenous-femoral disconnection, but TSFL could also be a reliable, safe and low-cost varicose mini-invasive surgery in outpatients. TPL appeared to be less reliable.

  6. Optimum level of inferior mesenteric artery ligation for the left-sided colorectal cancer

    Science.gov (United States)

    Guraya, Salman Y.

    2016-01-01

    Objectives: To compares the effectiveness and impact of high inferior mesenteric artery (IMA) versus low IMA ligation on 5-year survival, lymph node yield rates, and peri-operative morbidity and mortality. Methods: The databases of Educational Resources Information Centre (ERIC), the Web of Science, EBSCO and MEDLINE were searched using MeSH terms ‘colorectal cancer’, ‘inferior mesenteric artery’, ‘high ligation’, ‘low ligation’, ‘mesenteric lymph nodes’, ‘prognosis’, and ‘survival’. Only clinical studies were selected and review articles and meta-analysis were excluded. In cases of duplicate cohorts, only the latest article was included. Irrelevant articles and the articles on both right and left sided CRC were excluded. The finally selected studies were analysed for the defined end-point outcomes. Results: The published data has shown that high IMA ligation improves the yield of harvested lymph node that allows accurate tumor staging and a more reliable estimation of prognosis. High ligation was not found to be positively correlated with increased anastomotic leakage or impaired genito-urinary function. However, high ligation demands advanced surgical expertise and longer operating time. There was no significant difference in 5-year survival rates for both techniques. Some studies have reported fatal complications of high ligation such as proximal bowel necrosis. Conclusion: Although there is no consensus, this research signals the routine use of high ligation for left-sided CRC. However, the published fatal complications following high ligation and no significant difference in 5-year survival rates demand more studies to establishing a unified protocol. PMID:27381531

  7. Nitrogen Removal From Dairy Manure Wastewater Using Sequencing Batch Reactors

    OpenAIRE

    Whichard, David P

    2001-01-01

    The purpose of this research was to characterize a flushed dairy manure wastewater and to develop the kinetic and stoichiometric parameters associated with nitrogen removal from the wastewater, as well as to demonstrate experimental and simulated nitrogen removal from the wastewater. The characterization showed that all the wastewaters had carbon to nitrogen ratios large enough for biological nitrogen removal. Analysis of carbon to phosphorus ratios showed that enough carbon is available fo...

  8. Comparison and transfer testing of multiplex ligation detection methods for GM plants

    Directory of Open Access Journals (Sweden)

    Ujhelyi Gabriella

    2012-01-01

    Full Text Available Abstract Background With the increasing number of GMOs on the global market the maintenance of European GMO regulations is becoming more complex. For the analysis of a single food or feed sample it is necessary to assess the sample for the presence of many GMO-targets simultaneously at a sensitive level. Several methods have been published regarding DNA-based multidetection. Multiplex ligation detection methods have been described that use the same basic approach: i hybridisation and ligation of specific probes, ii amplification of the ligated probes and iii detection and identification of the amplified products. Despite they all have this same basis, the published ligation methods differ radically. The present study investigated with real-time PCR whether these different ligation methods have any influence on the performance of the probes. Sensitivity and the specificity of the padlock probes (PLPs with the ligation protocol with the best performance were also tested and the selected method was initially validated in a laboratory exchange study. Results Of the ligation protocols tested in this study, the best results were obtained with the PPLMD I and PPLMD II protocols and no consistent differences between these two protocols were observed. Both protocols are based on padlock probe ligation combined with microarray detection. Twenty PLPs were tested for specificity and the best probes were subjected to further evaluation. Up to 13 targets were detected specifically and simultaneously. During the interlaboratory exchange study similar results were achieved by the two participating institutes (NIB, Slovenia, and RIKILT, the Netherlands. Conclusions From the comparison of ligation protocols it can be concluded that two protocols perform equally well on the basis of the selected set of PLPs. Using the most ideal parameters the multiplicity of one of the methods was tested and 13 targets were successfully and specifically detected. In the

  9. Effects of double ligation of Stensen's duct on the rabbit parotid gland.

    Science.gov (United States)

    Maria, O M; Maria, S M; Redman, R S; Maria, A M; Saad El-Din, T A; Soussa, E F; Tran, S D

    2014-04-01

    Salivary gland duct ligation is an alternative to gland excision for treating sialorrhea or reducing salivary gland size prior to tumor excision. Duct ligation also is used as an approach to study salivary gland aging, regeneration, radiotherapy, sialolithiasis and sialadenitis. Reports conflict about the contribution of each salivary cell population to gland size reduction after ductal ligation. Certain cell populations, especially acini, reportedly undergo atrophy, apoptosis and proliferation during reduction of gland size. Acini also have been reported to de-differentiate into ducts. These contradictory results have been attributed to different animal or salivary gland models, or to methods of ligation. We report here a bilateral double ligature technique for rabbit parotid glands with histologic observations at 1, 7, 14, 30, 60 days after ligation. A large battery of special stains and immunohistochemical procedures was employed to define the cell populations. Four stages with overlapping features were observed that led to progressive shutdown of gland activities: 1) marked atrophy of the acinar cells occurred by 14 days, 2) response to and removal of the secretory material trapped in the acinar and ductal lumens mainly between 30 and 60 days, 3) reduction in the number of parenchymal (mostly acinar) cells by apoptosis that occurred mainly between 14-30 days, and 4) maintenance of steady-state at 60 days with a low rate of fluid, protein, and glycoprotein secretion, which greatly decreased the number of leukocytes engaged in the removal of the luminal contents. The main post- ligation characteristics were dilation of ductal and acinar lumens, massive transient infiltration of mostly heterophils (rabbit polymorphonuclear leukocytes), acinar atrophy, and apoptosis of both acinar and ductal cells. Proliferation was uncommon except in the larger ducts. By 30 days, the distribution of myoepithelial cells had spread from exclusively investing the intercalated ducts

  10. A comparison of self-ligating and conventional orthodontic bracket systems.

    Science.gov (United States)

    Read-Ward, G E; Jones, S P; Davies, E H

    1997-11-01

    This ex-vivo study compared the static frictional resistance of three self-ligating brackets with a conventional steel-ligated Ultratrimm bracket. The effects of archwire size (0.020, 0.019 x 0.025 and 0.021 x 0.025-inch), bracket/archwire angulation (0, 5 and 10 degrees) and the presence of unstimulated human saliva were investigated. The study demonstrated that both increases in wire size and bracket/archwire angulation resulted in increased static frictional resistance for all bracket types tested, with the presence of saliva having an inconsistent effect. Mobil-Lock Variable-Slot had the least friction for all wires for 0 degree angulation. However, with the introduction of angulation, the values were comparable to those of the other brackets. Activa brackets had the second lowest frictional resistance, although high values were found with 0.019 x 0.025-inch wires. SPEED brackets demonstrated low forces with round wires, although with rectangular wires or in the presence of angulation, friction was greatly increased. Ultratrimm brackets produced large individual variation, confirming the difficulty in standardizing ligation force, although under certain conditions, significantly larger frictional forces were observed. In conclusion, self-ligating brackets showed reduced frictional resistance in comparison to steel ligated brackets only under certain conditions. PMID:9459030

  11. Controllable Mismatched Ligation for Bioluminescence Screening of Known and Unknown Mutations.

    Science.gov (United States)

    Xu, Qinfeng; Huang, Si-qiang; Ma, Fei; Tang, Bo; Zhang, Chun-yang

    2016-02-16

    Single-nucleotide polymorphisms (SNPs) are closely related to human diseases and individual drug responses, and the accurate detection of SNPs is crucial to both clinical diagnosis and development of personalized medicine. Among various SNPs detection methods, ligase detection reaction (LDR) has shown great potential due to its low detection limit and excellent specificity. However, frequent involvement of expensive labels increases the experimental cost and compromises the assay efficiency, and the requirement of careful predesigned probes limits it to only known SNPs assays. In this research, we develop a controllable mismatched ligation for bioluminescence screening of both known and unknown mutations. Especially, the ligation specificity of E. coli ligase is tunable under different experimental conditions. The mismatches locating on the 3'-side of the nick cannot be ligated efficiently by E. coli ligase, whereas all mismatches locating on the 5'-side of the nick can be ligated efficiently by E. coli ligase. We design a 3'-discriminating probe (3'-probe) for the discrimination of known mutation and introduce a T7 Endo I for the detection of unknown mutation. With the integration of bioluminescence monitoring of ligation byproduct adenosine 5'-monophosphate (AMP), both known and unknown SNPs can be easily detected without the involvement of any expensive labels and labor-intensive separation. This method is simple, homogeneous, label-free, and cost-effective and may provide a valuable complement to current sequencing technologies for disease diagnostics, personalized medicine, and biomedical research. PMID:26754165

  12. The Diels-Alder-Reaction with inverse-Electron-Demand, a very efficient versatile Click-Reaction Concept for proper Ligation of variable molecular Partners

    Directory of Open Access Journals (Sweden)

    Manfred Wiessler, Waldemar Waldeck, Christian Kliem, Ruediger Pipkorn, Klaus Braun

    2010-01-01

    Full Text Available The ligation of active pharmaceutical ingredients (API for working with image processing systems in diagnostics (MRT attracts increasing notice and scientific interest. The Diels-Alder ligation Reaction with inverse electron demand (DARinv turns out to be an appropriate candidate. The DARinv is characterized by a specific distribution of electrons of the diene and the corresponding dienophile counterpart. Whereas the reactants in the classical Diels-Alder Reaction feature electron-rich diene and electron-poor dienophile compounds, the DARinv exhibits exactly the opposite distribution of electrons. Substituents with pushing electrones increase and, with pulling electrons reduce the electron density of the dienes as used in the DARinv. We report here that the DARinv is an efficient route for coupling of multifunctional molecules like active peptides, re-formulated drugs or small molecules like the alkyalting agent temozolomide (TMZ. This is an example of our contribution to the "Click chemistry" technology. In this case TMZ is ligated by DARinv as a cargo to transporter molecules facilitating the passage across the cell membranes into cells and subsequently into subcellular components like the cell nucleus by using address molecules. With such constructs we achieved high local concentrations at the desired target site of pharmacological action. The DARinv ligation was carried out using the combination of several technologies, namely: the organic chemistry and the solid phase peptide synthesis which can produce 'tailored' solutions for questions not solely restricted to the medical diagnostics or therapy, but also result in functionalizations of various surfaces qualified amongst others also for array development. We like to acquaint you with the DARinv and we like to exemplify that all ligation products were generated after a rapid and complete reaction in organic solutions at room temperature, in high purity, but also, hurdles and difficulties on

  13. The Diels-Alder-reaction with inverse-electron-demand, a very efficient versatile click-reaction concept for proper ligation of variable molecular partners.

    Science.gov (United States)

    Wiessler, Manfred; Waldeck, Waldemar; Kliem, Christian; Pipkorn, Ruediger; Braun, Klaus

    2009-12-05

    The ligation of active pharmaceutical ingredients (API) for working with image processing systems in diagnostics (MRT) attracts increasing notice and scientific interest. The Diels-Alder ligation Reaction with inverse electron demand (DAR(inv)) turns out to be an appropriate candidate. The DAR(inv) is characterized by a specific distribution of electrons of the diene and the corresponding dienophile counterpart. Whereas the reactants in the classical Diels-Alder Reaction feature electron-rich diene and electron-poor dienophile compounds, the DAR(inv) exhibits exactly the opposite distribution of electrons. Substituents with pushing electrones increase and, with pulling electrons reduce the electron density of the dienes as used in the DAR(inv).We report here that the DAR(inv) is an efficient route for coupling of multifunctional molecules like active peptides, re-formulated drugs or small molecules like the alkyalting agent temozolomide (TMZ). This is an example of our contribution to the "Click chemistry" technology. In this case TMZ is ligated by DAR(inv) as a cargo to transporter molecules facilitating the passage across the cell membranes into cells and subsequently into subcellular components like the cell nucleus by using address molecules. With such constructs we achieved high local concentrations at the desired target site of pharmacological action. The DAR(inv) ligation was carried out using the combination of several technologies, namely: the organic chemistry and the solid phase peptide synthesis which can produce 'tailored' solutions for questions not solely restricted to the medical diagnostics or therapy, but also result in functionalizations of various surfaces qualified amongst others also for array development.We like to acquaint you with the DAR(inv) and we like to exemplify that all ligation products were generated after a rapid and complete reaction in organic solutions at room temperature, in high purity, but also, hurdles and difficulties on

  14. The Diels-Alder-Reaction with inverse-Electron-Demand, a very efficient versatile Click-Reaction Concept for proper Ligation of variable molecular Partners

    Science.gov (United States)

    Wiessler, Manfred; Waldeck, Waldemar; Kliem, Christian; Pipkorn, Ruediger; Braun, Klaus

    2010-01-01

    The ligation of active pharmaceutical ingredients (API) for working with image processing systems in diagnostics (MRT) attracts increasing notice and scientific interest. The Diels-Alder ligation Reaction with inverse electron demand (DARinv) turns out to be an appropriate candidate. The DARinv is characterized by a specific distribution of electrons of the diene and the corresponding dienophile counterpart. Whereas the reactants in the classical Diels-Alder Reaction feature electron-rich diene and electron-poor dienophile compounds, the DARinv exhibits exactly the opposite distribution of electrons. Substituents with pushing electrones increase and, with pulling electrons reduce the electron density of the dienes as used in the DARinv. We report here that the DARinv is an efficient route for coupling of multifunctional molecules like active peptides, re-formulated drugs or small molecules like the alkyalting agent temozolomide (TMZ). This is an example of our contribution to the "Click chemistry" technology. In this case TMZ is ligated by DARinv as a cargo to transporter molecules facilitating the passage across the cell membranes into cells and subsequently into subcellular components like the cell nucleus by using address molecules. With such constructs we achieved high local concentrations at the desired target site of pharmacological action. The DARinv ligation was carried out using the combination of several technologies, namely: the organic chemistry and the solid phase peptide synthesis which can produce 'tailored' solutions for questions not solely restricted to the medical diagnostics or therapy, but also result in functionalizations of various surfaces qualified amongst others also for array development. We like to acquaint you with the DARinv and we like to exemplify that all ligation products were generated after a rapid and complete reaction in organic solutions at room temperature, in high purity, but also, hurdles and difficulties on the way to the

  15. GASTROPROTECTIVE EFFECTS OF FRUITS OF TRIBULUS TERRESTRIS L. IN PYLORUS-LIGATED WISTAR RAT MODEL

    Directory of Open Access Journals (Sweden)

    Sanjay Jain*, Rakesh Barik, Nidhi Yadav and Shivpal Singh

    2013-01-01

    Full Text Available Tribulus terrestris L. (TT; Zygophyllaceae is employed in the folk medicine against sexual impotence, oedemas, abdominal distention and cardiovascular diseases. Gastroprotective (i.e. antiulcer and anti-secretory potential of methanolic extract of TT fruits was evaluated in pylorus-ligated rat model of Wistar rat. The methanolic extract of TT was tested orally at the doses of 150, 300 & 600 mg/kg, on gastric ulcerations experimentally induced by pylorus ligation. Preliminary phytochemical screening of the methanol extract of TT showed the presence of alkaloids, carbohydrates, cardiac glycosides, flavonoids, saponins, tannins and proteins. The methanolic extract at the doses of 300 & 600 mg/kg produced more significant inhibition when gastric ulcerations were induced by pylorus ligation respectively. The methanol extract of the fruits of Tribulus terrestris L. possess gastroprotective i.e. antiulcer and anti-secretory effect.

  16. The effect of ligation of the distal vein in snuff-box arteriovenous fistula.

    Science.gov (United States)

    Beigi, Ali Akbar; Masoudpour, Hassan; Alavi, Maryam

    2009-11-01

    Arterio-venous fistula (AVF) in the snuff-box region is one of the current techniques used for creating a vascular access in patients undergoing dialysis. The aim of this study is to find out whether ligating the distal vein in AVF in the snuff-box will bring about any change in the efficiency and complications of the fistula. Sixty patients (30 males, 30 females) suffering from chronic renal failure, who had been admitted for creating an AVF, were randomly divided into two groups after having filled out consent forms. After the AVF was made, the distal vein was ligated in the first group, but not in the second group. The patients were discharged after being given the necessary advice on how to take care of their fistula. They were examined on post-surgical days 1, 30 and 90. Early efficiency in the ligated and non-ligated groups was 100% and 96.7% respectively while late efficiency in the two groups was 90% and 83.4%, respectively (P > 0.05). The most common complication in both groups was thrombosis (11.7%). Venous hypertension and edema were observed in two patients (both from the non-ligated group) and infection of the surgical site was observed in only one patient. Our study suggests that, considering the high efficiency level and low complication rate, AVF at the snuff-box region constitutes one of the best possible vascular accesses for patients undergoing hemodialysis. Ligation of the distal vein prevents the development of venous hypertension in the fistula. PMID:19861886

  17. An Immunocytochemical Profile of the Endocrine Pancreas Using an Occlusive Duct Ligation Model.

    Directory of Open Access Journals (Sweden)

    Page BJ

    2000-11-01

    Full Text Available CONTEXT: Ligation of the pancreatic duct, distally to its confluence into the bile duct has been shown to induce endocrine tissue regeneration. The surplus endocrine tissue formed is presumed to be able to replace pathologically and/or experimentally compromised tissue. OBJECTIVE: This is a quantitative study on the histology of duct ligated pancreas employing immunocytochemistry and computerised morphometry. INTERVENTIONS: Pancreatic duct ligation was performed on 25 groups of six normal Sprague-Dawley rats. Experimental animals were sacrificed at 12-hour intervals from day one to ten post-duct ligation and every 24 hours thereafter to day 14, the pancreas removed, fixed and processed. Six consecutive 3-6 micron serial sections were cut on a rotary hand microtome, floated onto 3-aminopropyl-trimethoxysilan coated slides and alternatively immunocytochemically stained for insulin, glucagon, pancreatic polypeptide and somatostatin. RESULTS: Pancreas transformation between days 1/2 and 3 1/2 was characterised by acinar deletion and the appearance of immunoreactive cells for the primary endocrine hormones. Transdifferentiation of existing endocrine tissue saw islet insulin core cells replaced by pancreatic polypeptide- and somatostatin positive cells, glucagon deletion and random appearance of all endocrine cell types within the inter-islet interstitium by day 3 1/2. Days 4 to 14 were characterised by cellular migration and islet reconstruction. CONCLUSIONS: To date our laboratory has investigated transplantation of foetal tissue beneath the renal capsule in syngeneic, isogeneic and allogeneic normal and diabetic rats. As pancreatic duct ligation induces the development of surplus endocrine tissue our next step would be to investigate the use of ligated pancreas as a replacement for foetal tissue.

  18. The effect of ligation of the distal vein in snuff-box arteriovenous fistula

    Directory of Open Access Journals (Sweden)

    Beigi Ali

    2009-01-01

    Full Text Available Arterio-venous fistula (AVF in the snuff-box region is one of the current techniques used for creating a vascular access in patients undergoing dialysis. The aim of this study is to find out whether ligating the distal vein in AVF in the snuff-box will bring about any change in the efficiency and complications of the fistula. Sixty patients (30 males, 30 females suffering from chronic renal failure, who had been admitted for creating an AVF, were randomly divided into two groups after having filled out consent forms. After the AVF was made, the distal vein was ligated in the first group, but not in the second group. The patients were discharged after being given the necessary advice on how to take care of their fistula. They were examined on post-surgical days 1, 30 and 90. Early efficiency in the ligated and non-ligated groups was 100% and 96.7% respectively while late efficiency in the two groups was 90% and 83.4%, respectively (P > 0.05. The most common complication in both groups was thrombosis (11.7%. Venous hypertension and edema were observed in two patients (both from the non-ligated group and infection of the surgical site was observed in only one patient. Our study suggests that, considering the high efficiency level and low complication rate, AVF at the snuff-box region constitutes one of the best possible vascular accesses for patients undergoing hemodialysis. Ligation of the distal vein prevents the development of venous hypertension in the fistula.

  19. Chronic heart failure model with sequential ligation of the homonymous artery and its diagonal branch in the sheep.

    Science.gov (United States)

    Kim, W G; Park, J J; Oh, S I

    2001-01-01

    We report a reliable chronic heart failure model in sheep using sequential ligation of the homonymous artery and its diagonal branch. After a left anterior thoracotomy in Corridale sheep, the homonymous artery was ligated at a point approximately 40% of the distance from the apex to the base of the heart, and after 1 hour, the diagonal vessel was ligated at a point at the same level. Hemodynamic measurements were done preligation, 30 minutes after the homonymous artery ligation, and 1 hour after diagonal branch ligation. The electrocardiograms were obtained as needed, and cardiac function was also evaluated with ultrasonography. After a predetermined interval (2 months for five animals and 3 months for two animals), the animals were reevaluated in the same way as before, and were killed for postmortem examination of their hearts. All seven animals survived the experimental procedures. Statistically significant decreases in systemic arterial blood pressure and cardiac output and increases in pulmonary artery capillary wedge pressure were observed 1 hour after sequential ligation of the homonymous artery and its diagonal branch. Untrasonographic analyses demonstrated variable degrees of anteroseptal dyskinesia and akinesia in all animals. The data from animals at 2 months after coronary artery ligation showed significant increases in central venous pressure, pulmonary artery pressure, and pulmonary artery capillary wedge pressure. Left ventricular enddiastolic dimension and left ventricular end-systolic dimension on ultrasonographic studies were also increased. Electrocardiography showed severe ST elevation immediately after the ligation and pathologic Q waves were found at 2 months after ligation. The thin walled infarcted areas with chamber enlargement were clearly seen in the hearts removed at 2 and 3 months after ligation. In conclusion, we could achieve a reliable ovine model of chronic heart failure using a simple concept of sequential ligation of the

  20. INTERNAL ILIAC ARTERY LIGATION AFTER CAESERIAN HYSTERECTOMY IN POST - PARTUM HAEMORRHAGE LIFE SAVING PROCEDURE

    Directory of Open Access Journals (Sweden)

    Vijayalakshmi

    2015-07-01

    Full Text Available Internal iliac artery (Hypogastric supplies the pelvic viscera. Bilateral ligation of the internal iliac arteries is a safe, rapid and very effective method of controlling bleeding from genital tract. It is also helpful in massive broad ligament hematoma, in torn vessels retracted within th e broad ligament, and even in postoperative hemorrhage after abdominal or vaginal hysterectomy where there are no definitive bleeding points detectable. Bilateral ligation of internal iliac arteries is also helpful in life threatening hemorrhagic condition s like postpartum hemorrhage, placenta previa, cervical and vaginal tear, cervical pregnancy and uterine rupture etc.

  1. Level of arterial ligation in sigmoid colon and rectal cancer surgery

    OpenAIRE

    YASUDA, KOJI; Kawai, Kazushige; ISHIHARA, SOICHIRO; Murono, Koji; Otani, Kensuke; Nishikawa, Takeshi; Tanaka, Toshiaki; Kiyomatsu, Tomomichi; Hata, Keisuke; NOZAWA, HIROAKI; Yamaguchi, Hironori; Aoki, Shigeo; Mishima, Hideyuki; Maruyama, Tsunehiko; Sako, Akihiro

    2016-01-01

    Background Curative resection of sigmoid colon and rectal cancer includes “high tie” of the inferior mesenteric artery (IMA). However, IMA ligation compromises blood flow to the anastomosis, which may increase the leakage rate, and it is unclear whether this confers a survival advantage. Accordingly, the IMA may be ligated at a point just below the origin of the left colic artery (LCA) “low tie” combined with lymph node dissection (LND) around the origin of the IMA (low tie with LND). However...

  2. ROLE OF INTERNAL ILIAC ARTERY LIGATION IN CONTROL OF PELVIC HEMORRHAGE.

    Directory of Open Access Journals (Sweden)

    Vidyadhar Bangal

    2009-06-01

    Full Text Available Hemorrhage in pregnancy is the leading cause of maternal mortality in developing countries. Internaliliac artery ligation is one of the life saving procedures in intractable pelvic hemorrhage. Althougheffective, the procedure is not commonly performed by obstetricians and gynecologists. Present paper aims at sharing author’s experience about usefulness of this surgical procedure in arrest of pelvic hemorrhage and to remove the inhibition among practicing gynecologists regarding this procedure.Fifty four cases of pelvic hemorrhage were managed by internal iliac artery ligation over 15 year period at tertiary care center. Hemorrhage could be arrested in all cases.

  3. Impairment of the organization of locomotor and exploratory behaviors in bile duct-ligated rats

    DEFF Research Database (Denmark)

    Leke, Renata; de Oliveira, Diogo L; Mussulini, Ben Hur M.;

    2012-01-01

    female Wistar rats underwent common bile duct ligation (BDL rats) or the manipulation of common bile duct without ligation (control rats). Six weeks after surgery, control and BDL rats underwent open-field, plus-maze and foot-fault behavioral tasks. The BDL rats developed chronic liver failure...... from the control rats for the elevated plus-maze and foot-fault tasks. Therefore, the BDL rats demonstrated disturbed spontaneous locomotor and exploratory activities as a consequence of altered spatio-temporal organization of behavior....

  4. Coronary ligation reduces maximum sustained swimming speed in Chinook salmon, Oncorhynchus tshawytscha

    DEFF Research Database (Denmark)

    Farrell, A P; Steffensen, J F

    1987-01-01

    The maximum aerobic swimming speed of Chinook salmon (Oncorhynchus tshawytscha) was measured before and after ligation of the coronary artery. Coronary artery ligation prevented blood flow to the compact layer of the ventricular myocardium, which represents 30% of the ventricular mass, and produced...... a statistically significant 35.5% reduction in maximum swimming speed. We conclude that the coronary circulation is important for maximum aerobic swimming and implicit in this conclusion is that maximum cardiac performance is probably necessary for maximum aerobic swimming performance....

  5. Bis-ligated Ti and Zr complexes of chelating N-heterocyclic carbenes

    KAUST Repository

    El-Batta, Amer

    2011-07-01

    In this communication we report the synthesis of novel titanium and zirconium complexes ligated by bidentate "salicylaldimine-like" N-heterocyclic carbenes (NHC). Double addition of the NHC chelate to either TiCl4(thf)2 or ZrCl4 forms bis-ligated organometallic fragments with a distorted octahedral geometry. These complexes are rare examples of group IV transition-metal NHC adducts. Preliminary catalytic tests demonstrate that in the presence of methylaluminoxane (MAO) these complexes are useful initiators for the polymerization of ethylene and the copolymerization of ethylene with norbornene and 1-octene. © 2011 Elsevier B.V. All rights reserved.

  6. Development of a 11C-labeled tetrazine for rapid tetrazine–trans-cyclooctene ligation

    DEFF Research Database (Denmark)

    Herth, Matthias Manfred; Andersen, Valdemar L.; Lehel, Szabolcs;

    2013-01-01

    Tetrazine–trans-cyclooctene ligations are remarkably fast and selective reactions even at low micro-molar concentrations. In bioorthogonal radiochemistry, tools that enable conjugation of radioactive probes to pre-targeted vectors are of great interest. Herein, we describe the successful developm......Tetrazine–trans-cyclooctene ligations are remarkably fast and selective reactions even at low micro-molar concentrations. In bioorthogonal radiochemistry, tools that enable conjugation of radioactive probes to pre-targeted vectors are of great interest. Herein, we describe the successful...

  7. Enzymatic Ligation Creates Discrete Multi-Nanoparticle Building Blocks for Self-Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Claridge, Shelley A.; Mastroianni, Alexander J.; Au, Yeung B.; Liang, Huiyang W.; Micheel, Christine M.; Frechet, Jean M.J.; Alivisatos, A. Paul

    2008-05-27

    Enzymatic ligation of discrete nanoparticle?DNA conjugates creates nanoparticle dimer and trimer structures in which the nanoparticles are linked by single-stranded DNA, rather than double-stranded DNA as in previous experiments. Ligation is verified by agarose gel and small-angle X-ray scattering. This capability is utilized in two ways: first to create a new class of multiparticle building blocks for nanoscale self-assembly; second to develop a system which can amplify a population of discrete nanoparticle assemblies.

  8. Associated Liver Partition and Portal Vein Ligation (ALPPS) vs Selective Portal Vein Ligation (PVL) for Staged Hepatectomy in a Rat Model. Similar Regenerative Response?

    Science.gov (United States)

    García-Pérez, Rocío; Revilla-Nuin, Beatriz; Martínez, Carlos M; Bernabé-García, Angel; Baroja Mazo, Alberto; Parrilla Paricio, Pascual

    2015-01-01

    Associated liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a two-stage hepatectomy technique which can be associated with a hypertrophic stimulus on the future liver remnant (FLR) stronger than other techniques--such as portal vein ligation (PVL). However, the reason of such hypertrophy is still unclear, but it is suggested that liver transection combined with portal vein ligation (ALPPS) during the first stage of this technique may play a key role. The aim of this study is to compare the hypertrophic stimulus on the FLR and the clinical changes associated with both ALPPS and PVL in a rat surgical model. For this purpose, three groups of SD rats were used, namely ALPPS (n = 30), PVL (n = 30) and sham-treated (n = 30). The second stage of ALPPS (hepatectomy of the atrophic lobes), was performed at day 8. Blood and FLR samples were collected at 1, 24, 48 hours, 8 days and 12 weeks after the surgeries. ALPPS provoked a greater degree of hypertrophy of the FLR than the PVL at 48 hours and 8 days (pstimulus at 12 weeks, with a higher expression of HGF and TGF-β (presponse seems to be leaded by a complex interaction between pro-mitogenic (IL-6, HGF, TNF-α) and antiproliferative (IL1-β and TGF-β) cytokines.

  9. Characterization by SEM, TEM and Quantum-Chemical Simulations of the Spherical Carbon with Nitrogen (SCN Active Carbon Produced by Thermal Decomposition of Poly(vinylpyridine-divinylbenzene Copolymer

    Directory of Open Access Journals (Sweden)

    Vladyslav V. Lisnyak

    2009-09-01

    Full Text Available Amorphous Spherical Carbon with Nitrogen (SCN active carbon has been prepared by carbonization of poly(vinylpyridine-divinylbenzene (PVPDVB copolymer. The PVPDVB dehydrogenation copolymer has been quantum chemically (QC simulated using cluster and periodic models. Scanning electron microscopy (SEM, transmission electron microscopy (TEM and energy dispersive X-ray (EDX studies of the resulting product have conformed the QC computation results. Great structural similarity is found both at the nano- and micro-levels between the N-doped SCN carbon and its pure carbonic SKS analog.

  10. Optical and structural characterization of nitrogen-rich InN: Transition from nearly intrinsic to strongly n-type degenerate with temperature

    Energy Technology Data Exchange (ETDEWEB)

    Hong Tran, Nhung; Huy Le, Binh; Fan, Shizhao; Zhao, Songrui; Mi, Zetian [Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9 (Canada); Schmidt, Benjamin A.; Savard, Michel; Gervais, Guillaume [Department of Physics, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Butcher, Kenneth Scott A. [Meaglow Ltd., 1308 Piccard Avenue, Thunder Bay, P7G 1A7 Ontario (Canada)

    2013-12-23

    We report on a detailed study of the structural and optical properties of nonstoichiometric nitrogen-rich InN grown on sapphire substrates, by migration enhanced afterglow deposition. The samples were polycrystalline, with the presence of InN dots. Unusually strong photoluminescence emission was measured at cryogenic temperatures, with the peak energy at ∼0.68 eV. Detailed analysis further shows that the sample has very low residual electron density in the range of ∼10{sup 16} cm{sup −3} at temperatures below 20 K.

  11. IMPROVED MISCIBLE NITROGEN FLOOD PERFORMANCE UTILIZING ADVANCED RESERVOIR CHARACTERIZATION AND HORIZONTAL LATERALS IN A CLASS I RESERVOIR - EAST BINGER (MARCHAND) UNIT

    International Nuclear Information System (INIS)

    Budget Period 2 of the East Binger Unit (''EBU'') DOE Project has been. Recent activities included additional data gathering and project monitoring, plus initiation of work on an SPE paper on the modeling efforts of the project. Early production performance suggests horizontal wells do not provide sufficient additional production over vertical wells to justify their incremental cost. It will take more time to evaluate the impact of the horizontal wells on sweep and ultimate recovery, but it is unlikely that an improvement in recovery will be sufficient to make the overall economic value of horizontal wells greater than the economic value of vertical wells. Monitoring of overall performance of the pilot area continues. Overall response to the various projects continues to be very favorable. Injection into the pilot area has nearly doubled, while gas production and nitrogen content of produced gas have both decreased. Nitrogen recycle within the pilot area has dropped from 60% to 20%. Efforts to further disseminate knowledge gained through this project, by means of technical paper presentations to industry groups, are underway. Project monitoring and technology transfer will be focus areas of Budget Period 3

  12. Characterization of edge profiles and fluctuations in discharges with type-II and nitrogen-mitigated edge localized modes in ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Wolfrum, E; Bernert, M; Burckhart, A; Classen, I G J; Conway, G D; Eich, T; Fischer, R; Gude, A; Herrmann, A; Maraschek, M; McDermott, R; Puetterich, T; Wieland, B [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Garching (Germany); Boom, J E [FOM Institute for Plasmaphysics, Rijnhuizen, Association EURATOM-FOM, Nieuwegein (Netherlands); Luhmann, N C Jr [University of California at Davis, Davis, CA95616 (United States); Park, H K [POSTECH, Pohang, Gyeongbuk, 790-784 (Korea, Republic of); Vicente, J [Associacao EURATOM/IST, Instituto de Plasmas e Fosao Nuclear - Laboratorio Associado, IST, Lisbon (Portugal); Willensdorfer, M, E-mail: e.wolfrum@ipp.mpg.de [Institute of Applied Physics, Vienna University of Technology, Association EURATOM-OEAW, Vienna (Austria)

    2011-08-15

    Edge localized modes (ELMs) with high frequency and low power loss (type-II ELMs) occur in high triangularity, near double null configurations in ASDEX Upgrade with full tungsten plasma facing components. The transition from type-I to type-II ELMs is shown to occur above a collisionality threshold. For the first time the characteristic MHD fluctuations around 40 kHz have been localized. The fluctuations are observed in a wide region extending from the pedestal inward to normalized poloidal radius {rho}{sub pol} = 0.7. Their amplitudes on the low-field side of the plasma exhibit maxima above and below the mid-plane. The fluctuations move in the electron drift direction and lead to a reduced edge electron temperature gradient. The reduction in the edge pressure gradient is connected with these MHD fluctuations, which affect the electron temperature but not the electron density profiles. A comparison with nitrogen-mitigated type-I ELMs in the same plasma shape shows that core profiles are also affected. The electron temperature profile is self-similar for type-I and nitrogen-mitigated type-I ELMs but is not self-similar in the case of type-II ELMs.

  13. Ligation of the thoracic duct for the treatment of chylothorax in heart diseases

    Directory of Open Access Journals (Sweden)

    Pêgo-Fernandes Paulo M.

    2003-01-01

    Full Text Available In children, chylothorax occurs mainly after cardiac and thoracic surgeries. One of the recommended postsurgery treatments is ligation of the thoracic tract, when all other conservative treatments have failed. We report 4 cases of chylothorax in patients who were successfully treated with this approach, which resulted in a decrease in pleural drainage without recurrent chylothorax.

  14. Template Directed Oligomer Ligation in Eutectic Phases in Water-Ice

    DEFF Research Database (Denmark)

    Dörr, Mark; Löffler, Philipp M. G.; Wieczorek, Rafal;

    2011-01-01

    /multiplex to overcome product inhibition. The latest results of our template directed ligation experiments in the eutectic ice phase are presented. Different activation strategies are compared and an outlook towards applications in molecular evolution and artifical cell systems (« protocells ») will be given. Figure 1...

  15. Opening and closure forces of sliding mechanisms of different self-ligating brackets

    Directory of Open Access Journals (Sweden)

    Paola GANDINI

    2013-06-01

    Full Text Available Self-ligating brackets engage the wire by means of a slide mechanism. Forces that have to be applied to open and close the sliding mechanism of brackets are still unknown. Objective The aim of this study was to measure and compare the opening and closure forces of different self-ligating brackets. Material and Methods Three different stainless steel self-ligating brackets (Carriere LX, Ortho Organizers; F1000, Leone; Damon Q, Ormco were tested. For each different bracket, 20 maxillary right central incisors and 20 mandibular right central incisors were used. Opening and closure forces were measured using an Instron Universal Testing Machine. Statistical analysis was performed and ANOVA and Tukey tests were carried out. Results Opening forces were registered between 1.1 N and 5.6 N, whereas closure forces were recorded between 1.57 N and 4.87 N. Significant differences were detected among the different brackets and between the two prescriptions tested. Conclusion The knowledge of different opening and closure forces of self-ligating brackets can help the orthodontist in the clinical management of these devices.

  16. Aneurysm after surgical ligation of patent ductus arteriosus: a case report

    International Nuclear Information System (INIS)

    Patent ductus arteriosus (PDA) is one of the most common congenital heart diseases. A rare complication occurring after its surgical treatment is the development of an aneurysm, and we report the radiologic findings in a case in which this occurred after surgical ligation

  17. Catecholamine-resistant hypotension and myocardial performance following patent ductus arteriosus ligation.

    LENUS (Irish Health Repository)

    Noori, S

    2014-08-14

    Objective:We performed a multicenter study of preterm infants, who were about to undergo patent ductus arteriosus ligation, to determine whether echocardiographic indices of impaired myocardial performance were associated with subsequent development of catecholamine-resistant hypotension following ligation.Study Design:A standardized treatment approach for hypotension was followed at each center. Infants were considered to have catecholamine-resistant hypotension if their dopamine infusion was >15 μg kg(-1)min(-1). Echocardiograms and cortisol measurements were obtained between 6 and 14 h after the ligation (prior to the presence of catecholamine-resistant hypotension).Result:Forty-five infants were enrolled, 10 received catecholamines (6 were catecholamine-responsive and 4 developed catecholamine-resistant hypotension). Catecholamine-resistant hypotension was not associated with decreased preload, shortening fraction or ventricular output. Infants with catecholamine-resistant hypotension had significantly lower levels of systemic vascular resistance and postoperative cortisol concentration.Conclusion:We speculate that low cortisol levels and impaired vascular tone may have a more important role than impaired cardiac performance in post-ligation catecholamine-resistant hypotension.Journal of Perinatology advance online publication, 14 August 2014; doi:10.1038\\/jp.2014.151.

  18. Gingival response in orthodontic patients: Comparative study between self-ligating and conventional brackets.

    Science.gov (United States)

    Folco, Alejandra A; Benítez-Rogé, Sandra C; Iglesias, Marina; Calabrese, Diana; Pelizardi, Cristina; Rosa, Alcira; Brusca, Marisa I; Hecht, Pedro; Mateu, María E

    2014-01-01

    Orthodontic brackets contribute to the accumulation of bacterial plaque on tooth surfaces because they hinder oral hygiene. In contrast to conventional brackets, self-ligating brackets do not require additional parts to support the arches, thus improving dental hygiene. The aim of this study was to compare the gingival response in orthodontic patients wearing self-ligating or conventional brackets. A sample of 22 patients aged 16 to 30 years was divided into two groups: Group A, treated with selfligating brackets (Damon system) and Group B, treated with conventional brackets (Roth technique). The following were assessed during the treatment: Plaque Index (PI), Gingival Index (GI) and Probing Depth (PD), and sub-gingival samples were taken from teeth 14/24 for microbiological observation. No statistically significant difference was found between Groups A and B; p>0.05 (sign-ranked) or between PI, GI and PD at the different times (Friedman's Analysis of Variance), even though the indices were found to increase at 14 days, particularly for self-ligating brackets. The quantity and quality of microorganisms present were compatible with health on days 0, 28 and 56. As from day 14 there is a predominance of microbiota compatible with gingivitis in both groups. In the samples studied, orthodontic treatment increases bacterial plaque and inflammatory gingival response, but gingival-periodontal health can be maintained with adequate basic therapy. Self-ligating and conventional brackets produced similar gingival response. PMID:25560690

  19. Comparative study of proton pump inhibitors on dexamethasone plus pylorus ligation induced ulcer model in rats

    Directory of Open Access Journals (Sweden)

    Thippeswamy A. H. M.

    2010-01-01

    Full Text Available The present study was designed to compare ulcer protective effect of proton pump inhibitors viz. omeprazole, rabeprazole and lansoprazole against dexamethasone plus pylorus ligation induced ulcer model. Dexamethasone (5 mg/kg was used as an ulcerogen. Dexamethasone suspended in 1% CMC in water was given orally to all the rats 15 min after the pylorus ligation. Omeprazole (20 mg/kg, rabeprazole (20 mg/kg, and lansoprazole (20 mg/kg were administered by oral route 30 min prior to ligation was used for ulcer protective studies, gastric secretion and mucosal studies. Effects of proton pump inhibitors were determined by the evaluation of various biochemical parameters such as ulcer index, free and total acidity, gastric pH, mucin, pepsin and total proteins. Oral administration of proton pump inhibitors showed significant reduction in gastric acid secretion and ulcer protective activity against dexamethasone plus pylorus ligation induced ulcer model. The % protection of omeprazole, rabeprazole and lansoprazole was 84.04, 89.36 and 79.78, respectively. Rabeprazole significantly inhibited the acid-pepsin secretion and increased the gastric mucin secretion. The observations made in the present study suggest that rabeprazole is the most effective gastric antisecretory and ulcer healing agent as compared to omeprazole and lansoprazole.

  20. Ginger and Marshmallow Extracts Can Protect against Pyloric Ligation-Induced Peptic Ulcer in Rats

    Directory of Open Access Journals (Sweden)

    Sameh S. Zaghlool

    2015-03-01

    Full Text Available Gastric ulcer is one of the most serious diseases over wide the world. There are many drugs used for the treatment of gastric ulcer, but most of these produce several adverse reactions. This study aims to investigate the protective effects of extracts of Ginger and Marshmallow on pyloric ligation-induced gastric ulcer in rats. Animals were divided into 5 Groups; a normal control group, an ulcer control group, a standard treatment group receiving famotidine (20 mg/kg, and two treatment groups receiving Ginger (100 mg/kg and Marshmallow (100 mg/kg. Treatments were given orally for 14 days. On the 15th day, animals were subjected to pyloric ligation except for the normal control group. Four hours later, rat stomachs were excised and gastric juice and blood samples were collected. Pyloric ligation caused significant elevations in ulcer number, ulcer index, gastric volume, titratble acidity, acid output, mucin content and peptic activity, accompanied by significant decreases in blood superoxide dismutase activity (SOD activity and gastric mucosal nitric oxide (NO and glutathione (GSH contents. In addition, elevations in gastric mucosal lipid peroxide and histamine contents were observed. Pretreatment with famotidine, ginger or marshmallow significantly corrected all blood and tissue parameters by varying degrees. Famotidine, ginger and marshmallow may protect against pyloric ligation-induced peptic ulcer in rats, being promising for further clinical trials.

  1. Histamine receptors expressed in circulating progenitor cells have reciprocal actions in ligation-induced arteriosclerosis.

    Science.gov (United States)

    Yamada, Sohsuke; Wang, Ke-Yong; Tanimoto, Akihide; Guo, Xin; Nabeshima, Atsunori; Watanabe, Takeshi; Sasaguri, Yasuyuki

    2013-09-01

    Histamine is synthesized as a low-molecular-weight amine from L-histidine by histidine decarboxylase (HDC). Recently, we demonstrated that carotid artery-ligated HDC gene-deficient mice (HDC(-/-)) showed less neointimal formation than wild-type (WT) mice, indicating that histamine participates in the process of arteriosclerosis. However, little is known about the roles of histamine-specific receptors (HHRs) in arteriosclerosis. To define the roles of HHRs in arteriosclerosis, we investigated intimal remodeling in ligated carotid arteries of HHR-deficient mice (H1R(-/-) or H2R(-/-)). Quantitative analysis showed that H1R(-/-) mice had significantly less arteriosclerogenesis, whereas H2R(-/-) mice had more, as compared with WT mice. Bone marrow transplantation from H1R(-/-) or H2R(-/-) to WT mice confirmed the above observation. Furthermore, the increased expression of monocyte chemoattractant protein (MCP-1), platelet-derived growth factor (PDGF), adhesion molecules and liver X receptor (LXR)-related inflammatory signaling factors, including Toll-like receptor (TLR3), interleukin-1 receptor (IL-1R) and tumor necrosis factor receptor (TNF-R), was consistent with the arteriosclerotic phenotype of H2R(-/-) mice. Peripheral progenitor cells in H2R(-/-) mice accelerate ligation-induced arteriosclerosis through their regulation of MCP-1, PDGF, adhesion molecules and LXR-related inflammatory signaling factors. In contrast, peripheral progenitor cells act to suppress arteriosclerosis in H1R(-/-) mice, indicating that HHRs reciprocally regulate inflammation in the ligation-induced arteriosclerosis.

  2. ALIS-FLP: Amplified ligation selected fragment-length polymorphism method for microbial genotyping

    DEFF Research Database (Denmark)

    Brillowska-Dabrowska, A.; Wianecka, M.; Dabrowski, Slawomir;

    2008-01-01

    A DNA fingerprinting method known as ALIS-FLP (amplified ligation selected fragment-length polymorphism) has been developed for selective and specific amplification of restriction fragments from TspRI restriction endonuclease digested genomic DNA. The method is similar to AFLP, but differs...

  3. Ligation of lymph vessels for the treatment of recurrent inguinal lymphoceles following lymphadenectomy

    DEFF Research Database (Denmark)

    Toyserkani, Navid Mohamadpour; Nielsen, Henrik Toft; Bakholdt, Vivi;

    2016-01-01

    BACKGROUND: Recurrent lymphocele following groin dissection is generally a self-limiting condition, but in a few cases, the lymphocele persists and for this, there are not many options. Few reports have proposed the efficacy of lymph vessel ligation with patent blue as a vessel locator. We have u...

  4. Probing the stability of nonglycosylated wild-type erythropoietin protein via reiterative alanine ligations

    OpenAIRE

    Brailsford, John A.; Danishefsky, Samuel J.

    2012-01-01

    Nonglycosylated erythropoietin bearing acetamidomethyl protecting groups at the cysteine residues has been synthesized via chemical methods. Alanine ligation was used to assemble four peptide fragments, themselves prepared by solid phase peptide synthesis. This work outlines a route for the synthesis of homogeneous glycosylated erythropoietin.

  5. Screening of congenital heart disease patients using multiplex ligation-dependent probe amplification

    DEFF Research Database (Denmark)

    Sørensen, Karina Meden; El-Segaier, Milad; Fernlund, Eva;

    2012-01-01

    with CHD for CNVs in specific genomic regions may lead to early diagnosis and awareness of extracardiac symptoms. We designed a multiplex ligation-dependent probe amplification (MLPA) assay specifically for screening of CHD patients. The MLPA assay allows for simultaneous analysis of CNVs in 25 genomic...

  6. Multiplex Ligation-Dependent Probe Amplification of Uveal Melanoma : Correlation with Metastatic Death

    NARCIS (Netherlands)

    Damato, Bertil; Dopierala, Justyna; Klaasen, Annelies; van Dijk, Marcory; Sibbring, Julie; Coupland, Sarah E.

    2009-01-01

    PURPOSE. To evaluate multiplex ligation-dependent probe amplification (MLPA) of uveal melanoma as a predictive tool for metastatic death. METHODS. Uveal melanoma specimens of 73 patients treated between 1998 and 2000 were included. DNA samples were analyzed with MLPA evaluating 31 loci on chromosome

  7. Minimal access microsurgical ligation of spinal dural arteriovenous fistula with tubular retractor

    Directory of Open Access Journals (Sweden)

    Anderson Chun On Tsang

    2015-01-01

    Conclusion: With accurate localization of the fistulous point in each patient, only a hemilaminectomy and a small dura opening were required using the tube-assisted technique. This allows direct visualization and ligation of the fistulous point while minimizing postoperative morbidities.

  8. Structural characterization of the protein cce_0567 from Cyanothece 51142, a metalloprotein associated with nitrogen fixation in the DUF683 family

    Energy Technology Data Exchange (ETDEWEB)

    Buchko, Garry W.; Robinson, Howard; Addlagatta, Anthony

    2009-03-11

    The genome of many cyanobacacteria contain the sequence for a small protein (<100 amino acids) with a commom "domain of unknown function" grouped into the DUF683 protein family. While the biological function of DUF683 is still not known, their genomic location within nitrogen fixation clusters suggests that DUF683 proteins may play a role in the process. The diurnal cyanobacterium Cyanothece sp. PCC 51142 contains a gene for a protein that fall into the DUF683 family, cce_0567 (78 aa, 9.0 kDa). In an effort to elucidate the biochemical role DUF683 proteins may play in nitrogen fixation, we have determined the first crystal structure for a protein in this family, cce_0567, to 1.84 Å resolution. Cce_0567 crystallized in space group P21 with two protein molecules and one Ni2+ cation per asymmetric unit. The protein is composed of two α-helices from residues P11 to G41 (α1) and L49-E74 (α2) with the second α-helix containing a short 310-helix (Y46 - N48). A four-residue linker (L42 - D45) between the helices allows them to form an anti-parallel bundle that cross over each other towards their termini. In solution it is likely that two molecules of cce_0567 form a rod-like dimer by the stacking interactions of ~1/2 of the protein. Histidine-36 is highly conserved in all known DUF683 proteins and the N2 nitrogen of the H36 side chain of each molecule in the dimer coordinate with Ni2+ in the crystal structure. The divalent cation Ni2+ was titrated into 15N-labelled cce_0567 and chemical shift perturbations were observed only in the 1H-15N HSQC spectra for residues at, or near, the site of Ni2+ binding observed in the crystal structure. There was no evidence for an increase in the size of cce_0567 upon binding Ni2+, even in large molar excess of Ni2+, indicating that a metal was not required for dimer formation. Circular dichroism spectroscopy indicated that cce_0567 was extremely robust, with a melting temperature of ~62ºC that was reversible.

  9. Structural characterization of the protein cce_0567 from Cyanothece 51142, a metalloprotein associated with nitrogen fixation in the DUF683 family.

    Science.gov (United States)

    Buchko, Garry W; Robinson, Howard; Addlagatta, Anthony

    2009-04-01

    The genomes of many cyanobacteria contain the sequence for a small protein with a common "Domain of Unknown Function" grouped into the DUF683 protein family. While the biological function of DUF683 is still not known, their genomic location within nitrogen fixation clusters suggests that DUF683 proteins may play a role in the process. The diurnal cyanobacterium Cyanothece sp. PCC 51142 contains a gene for a protein that falls into the DUF683 family, cce_0567 (78 aa, 9.0 kDa). In an effort to elucidate the biochemical role DUF683 proteins may play in nitrogen fixation, we have determined the first crystal structure for a protein in this family, cce_0567, to 1.84 A resolution. Cce_0567 crystallized in space group P2(1) with two protein molecules and one Ni(2+) cation per asymmetric unit. The protein is composed of two alpha-helices, residues P11 to G41 (alpha1) and L49-E74 (alpha2), with the second alpha-helix containing a short 3(10)-helix (Y46-N48). A four-residue linker (L42-D45) between the helices allows them to form an anti-parallel bundle and cross over each other towards their termini. In solution it is likely that two molecules of cce_0567 form a rod-like dimer by the stacking interactions of approximately 1/2 of the protein. Histidine-36 is highly conserved in all known DUF683 proteins and the N2 nitrogen of the H36 side chain of each molecule in the dimer is coordinated with Ni(2+) in the crystal structure. The divalent cation Ni(2+) was titrated into (15)N-labeled cce_0567 and chemical shift perturbations were observed only in the (1)H-(15)N HSQC spectra for residues at, or near, the site of Ni(2+) binding observed in the crystal structure. There was no evidence for an increase in the size of cce_0567 upon binding Ni(2+), even in large molar excess of Ni(2+), indicating that a metal was not required for dimer formation. Circular dichroism spectroscopy indicated that cce_0567 was extremely robust, with a melting temperature of approximately 62 degrees C

  10. Structural Characterization of the Protein cce_0567 from Cyanothece 51142, a Metalloprotein Associated with Nitrogen Fixation in the DUF683 Family

    Energy Technology Data Exchange (ETDEWEB)

    Buchko, G.; Robinson, H; Addlagatta, A

    2009-01-01

    The genomes of many cyanobacteria contain the sequence for a small protein with a common 'Domain of Unknown Function' grouped into the DUF683 protein family. While the biological function of DUF683 is still not known, their genomic location within nitrogen fixation clusters suggests that DUF683 proteins may play a role in the process. The diurnal cyanobacterium Cyanothece sp. PCC 51142 contains a gene for a protein that falls into the DUF683 family, cce 0567 (78 aa, 9.0 kDa). In an effort to elucidate the biochemical role DUF683 proteins may play in nitrogen fixation, we have determined the first crystal structure for a protein in this family, cce 0567, to 1.84 A resolution. Cce 0567 crystallized in space group P2(1) with two protein molecules and one Ni(2+) cation per asymmetric unit. The protein is composed of two alpha-helices, residues P11 to G41 (alpha1) and L49-E74 (alpha2), with the second alpha-helix containing a short 3(10)-helix (Y46-N48). A four-residue linker (L42-D45) between the helices allows them to form an anti-parallel bundle and cross over each other towards their termini. In solution it is likely that two molecules of cce 0567 form a rod-like dimer by the stacking interactions of approximately 1/2 of the protein. Histidine-36 is highly conserved in all known DUF683 proteins and the N2 nitrogen of the H36 side chain of each molecule in the dimer is coordinated with Ni(2+) in the crystal structure. The divalent cation Ni(2+) was titrated into (15)N-labeled cce 0567 and chemical shift perturbations were observed only in the (1)H-(15)N HSQC spectra for residues at, or near, the site of Ni(2+) binding observed in the crystal structure. There was no evidence for an increase in the size of cce 0567 upon binding Ni(2+), even in large molar excess of Ni(2+), indicating that a metal was not required for dimer formation. Circular dichroism spectroscopy indicated that cce 0567 was extremely robust, with a melting temperature of approximately 62

  11. Prevalence and type of pain during conventional and self-ligating orthodontic treatment.

    Science.gov (United States)

    Tecco, Simona; D'Attilio, Michele; Tetè, Stefano; Festa, Felice

    2009-08-01

    This study investigated the prevalence and type of pain experienced during orthodontic treatment in 30 subjects (12 males, 18 females, aged 12-18 years) with crowding. Fifteen patients were treated with conventional brackets (Victory Series) and 15 with self-ligating brackets (Damon SL II). The first archwire for all patients was a 0.014 inch nickel-titanium (NiTi) archwire with a force of approximately 100 g. Conventional brackets were ligated with elastomeric modules. A visual analogue scale (VAS) was used daily to assess the intensity of pain; the use of pain medication was also reported in a specially designed daybook for a total period of 3 months. Pearson's chi-square was used to investigate the difference between groups in the frequency of pain experience, its nature, and the use of analgesia. Non-parametric statistics (Mann-Whitney U-test) were computed to compare pain intensity between the groups. To investigate reported pain assessments, Friedman's two-way analysis of variance was used and the differences were estimated using Wilcoxon's signed-rank test. The results showed that pain was reported for a period of 9 days after archwire insertion. Patients treated with self-ligating brackets reported the highest pain intensity on the day following placement of the first archwire (VAS mean = 42.6), while those treated with conventional brackets experienced the greatest pain intensity at placement of the first archwire (VAS mean = 52) and after the second orthodontic appointment (VAS mean = 59.6). Analgesics were used by 16.5 per cent of patients treated with self-ligating brackets and by 10 per cent of those treated with conventional brackets, most often during the first 2 days after archwire placement. Patients treated with conventional brackets reported significantly more 'constant' pain than those treated with self-ligating brackets who complained of 'chewing/biting' pain. Pain appears to be common during orthodontic treatment but perhaps less intense when

  12. Characterization and mechanistic analysis of the visible light response of cerium and nitrogen co-doped TiO2 nano-photocatalyst synthesized using a one-step technique

    International Nuclear Information System (INIS)

    Cerium and nitrogen co-doped anatase TiO2 nanoparticles were synthesized using a one-step technique via a modified sol-gel process and characterized by XRD, BET, DRS, Raman and XPS. The photocatalytic mechanism of the degradation of methylene blue (MB) under fluorescent light and visible light irradiation was studied. Co-doping cerium and nitrogen in the crystal lattice of TiO2 narrowed the band gap from 2.40 eV (Ce-doped TiO2) to 2.21 eV (Ce/N co-doped TiO2). Ce4+/Ce3+ pairs, oxynitride species and Ti-O-N and Ti-O-Ce bonds were determined by XPS. The recombination of photogenerated electron-hole pairs was inhibited due to the synergistic effect of doping with Ce4+/Ce3+ ions and N atoms. The optimal doping ratio was 0.70% Ce and 0.70% N using MB photocatalytic degradation under fluorescent light and visible light irradiation (λ > 420 nm). The enhanced photocatalytic degradation under visible light irradiation was attributed to the increasing number of photogenerated ·OH radicals. The recombination of photogenerated e--h+ was attributed to be the key factor for the decrease in the photocatalytic degradation efficiency of MB.

  13. A study of the frictional characteristics of four commercially available self-ligating bracket systems.

    Science.gov (United States)

    Budd, Steven; Daskalogiannakis, John; Tompson, Bryan D

    2008-12-01

    The objective of this investigation was to assess and compare the in vitro tribological behaviour of four commercially available self-ligating bracket systems. The frictional characteristics of the Damon3, Speed, In-Ovation R, and Time2 bracket systems were studied using a jig that mimics the three-dimensional movements that occur during sliding mechanics. Each bracket system was tested on the following stainless steel archwires: 0.016 x 0.022, 0.019 x 0.025, 0.020 round, and 0.021 x 0.021 inch Speed D-wire. An Instron testing machine with a 50 N load cell was used to measure the frictional resistance for each bracket/tooth assembly. The crosshead speed was set at a constant rate of 1 mm/minute, and each typodont tooth was moved along a fixed wire segment for a distance of 8 mm. Descriptive statistical analysis for each bracket/archwire combination with regard to frictional resistance was performed with a two-way, balanced analysis of variance for bracket type and wire size. The Damon3 bracket consistently demonstrated the lowest frictional resistance to sliding, while the Speed bracket produced significantly (P brackets tested for any given archwire. The self-ligation design (passive versus active) appears to be the primary variable responsible for the frictional resistance generated by self-ligating brackets during translation. Passively ligated brackets produce less frictional resistance; however, this decreased friction may result in decreased control compared with actively ligated systems. PMID:18974067

  14. Transcatheter closure of re-canalized patent ductus arteriosus after surgical ligation

    International Nuclear Information System (INIS)

    Objective: To evaluate the effectiveness of transcatheter closure of re-canalized patent ductus arteriosus (PDA) after surgical ligation. Methods: Between June 1995 and November 2000, 14 patients (5 male, 9 female) with re-canalized PDA after surgical ligation underwent transcatheter closure, their median age was 13 years (range 4 to 48 years). The time between surgical ligation and the interventional procedure ranged from one month to twenty-two years. Implantations of Amplatzer duct occluder and Rashkind occluder were performed trans-venously. Cook coil occlusions was performed trans-arterially. Follow-up with X-ray radiograph and echocardiography was made 24 hours, 1, 3, 6 months, and more than 1 year after the procedure. Results: Twelve PDAs were of funnel shape, and the remaining two PDAs were of tubular shape. The median minimum diameter of re-canalized PDA after ligation was 4 mm (range 1 to 8 mm). Aortograms ten minutes after closure showed complete closure and trivial residual shunt in 11 and 3 patients, respectively. The technical success rate was 100%, and there were no complications. Echocardiography showed complete closure in all patients within 24 hours. All patients were discharged in one to two days after the procedure. At a follow-up of one to eighteen months in ten patients, there were no migration of devices and residual PDA. Conclusion: Transcatheter closure using Amplatzer duct occluder, coil (Cook company or Pfm company) and Rashkind occluder was an effective method for patients with re-canalized PDA after surgical ligation. It may be an alternative to second surgery owing to its safety, reliability, min-invasiveness, and short hospitalization

  15. Routine chest drainage after patent ductus arteriosis ligation is not necessary.

    Directory of Open Access Journals (Sweden)

    Samuel Kai San YAPP

    2010-12-01

    Full Text Available Introduction: Chest drain insertion after surgical patent ductus arteriosus (PDA ligation creates significant morbidities in terms of pain, pleural space infection, reduced mobility as well as prolonged hospital stay. We investigated the safety and efficacy of performing drainless thoracotomy closure following PDA ligation in a paediatric population. Materials and Methods: Retrospective analysis of data collected from 13 paediatric patients undergoing PDA ligation at RIPAS hospital by a single surgeon over a period of five years (2001 to 2006 was performed. All continuous data were presented as mean ± standard deviation. Results: PDA ligation was performed via a left thoracotomy in 13 pediatric patients with a mean age of 2.24 ± 2.03 years (ten females and three males. Mean duration of the procedures was 67 ± 12 minutes. There was minimal blood loss and no transfusion was required. Postoperatively, ten patients required only oral paracetamol for pain relief. Two patients required additional non steroidal anti-inflammatory drugs (NSAIDs. One patient had one dose of pethidine immediately post-operatively. Post-operative chest radiographs confirmed full expansion of the left lung except in one patient who had a small apical pneumothorax. Two other patients developed mild surgical emphysema despite full expansion of the left lung. All three cases resolved spontaneously after a day. Median post-operative stay was two days. There were no cases of left recurrent nerve injuries and no mortality. Conclusion: Routine chest drainage is not necessary following uncomplicated surgical PDA ligation and patients recovered quicker and are discharge earlier.

  16. Radiological study on the change of duct-ligated parotid gland

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, Takashi (Higashi Nippon Gakuen Univ., Tobetsu, Hokkaido (Japan). School of Dentistry)

    1994-07-01

    The change of the parotid gland with time following ligation of the main duct was investigated. The duct-ligated parotid gland in rabbit was examined by salivary gland scintigraphy with [sup 99m]Tc-pertechnetate ([sup 99m]TcO[sub 4][sup -]), sialography and microscopic observation. The third day after ligation of the main duct, the outward form of the parotid gland on the static scintigram was not well-defined. On the seventh day, [sup 99m]TcO[sub 4][sup -] accumulation was decreased slightly. On the 14th day, atrophy of the parotid gland occurred. The degree of atrophy produced by ligation increases as the duration of the ligation increases. On the 42nd day, the presence of the parotid gland was not recorded practically. The main duct was dilated on the third day. On the seventh day, the intraglandular ducts were bent and strictured. Disappearance of the peripheral duct and atrophy of the parotid gland parenchyma was observed. On microscopic observation, the intraglandular tributaries and the lumen were dilated on the third day. And the reticular fiber was observed that was irregularly formed in parts. The acinar cells were pressed by large and small dilated lumen on the seventh day. On the 14th day, the collagenous fiber around the acini and the duct was increased still more. In addition, fibrosis of the lobule interspace was observed. The degree of atrophy of the acini and lobule was increased maximally on the 42nd day. These results of the salivary gland scintigraphy closely connected with sialograms and microscopic findings. The parotid gland tissue decreases and changings of the duct system were indicated by these imaging methods in detail. (author).

  17. A new technique of combined endoscopic sclerotherapy and ligation for variceal bleeding

    Institute of Scientific and Technical Information of China (English)

    Radha K. Dhiman; Yogesh K. Chawla

    2003-01-01

    AIM: To develop a technique of combined endoscopic sclerotherapy and ligation (ESL) in which both techniques of endoscopic sclerotherapy (ES) and endoscopic variceal ligation (EVL) can be optimally used.METHODS: ESL was performed in 10 patients (age 46.4±7.9;9 males, 1 female) with cirrhosis of liver using sclerotherapy needle and Speedband, Superview multiple band ligater (Boston Scientific, Microvasive, Watertown, MA). A single band was placed 5-10 cm proximal to the gastro-esophageal junction over each varix from proximal to distal margin,followed by intravariceal injection of 1.5 % ethoxysclerol (4 ml each) 2 to 3 cm proximal to the gastroesophageal junction on the ligated varices distal to deployed band. EVL was then performed at the injection site. Similarly other varices were also injected and ligated from distal to proximally. In the subsequent sessions, ES alone was performed to sclerose small varices at the gastroesophageal junction.RESULTS: ESL was successfully performed in all patients.A median of 3 (ESL 1, ES 2) sessions (ranged 1-4) were required to eradicate the varices in 9 (90 %) of 10 patients.Recurrence of varices without bleed was seen in 1 patient during a mean follow-up of 10.3 months (ranged 6-15).Two patients died of liver failure. None died of variceal bleeding. None of the patients had procedure related complications.CONCLUSION: ESL may be useful in the fast eradication of esophageal varices. However, randomised controlled trials are required to find out its relative efficacy and impact on variceal recurrence in comparison to ES or EVL.

  18. 生物质氮磷自掺杂二氧化钛的制备和表征%Synthesis and characterization of TiO2 self-doped with biogenic nitrogen and phosphorus

    Institute of Scientific and Technical Information of China (English)

    韩婷; 姚炜; 张豪杰; 范同祥; 何丹农

    2011-01-01

    选取黄豆为生物质氮磷源,以水溶性钛化合物为钛源,经过酸洗、水溶性钛化合物浸泡、梯度干燥和500℃烧结,得到氮磷掺杂二氧化钛.通过X射线衍射仪和X射线光电子能谱仪分析所得样品的结构和成分,表明其为单相锐钛矿结构的二氧化钛,且黄豆本身所含的氮、磷元素自掺杂到晶格中;UV-Vis吸收光谱显示,与未掺杂二氧化钛相比,氮磷掺杂二氧化钛在紫外可见光区吸收增强,且吸收边发生红移.光催化降解试验表明氮磷掺杂二氧化钛对罗丹明6G溶液的降解速率是未掺杂二氧化钛的1.4倍.利用废弃生物质进行自掺杂的方法避免了人工掺杂方法所需的有毒化学试剂的添加,有望推广到其他氮磷掺杂金属氧化物的制备中.%Soybeans and water-soluble titanium complexes are selected as biogenic nitrogen and phosphorus sources respectively to synthesize biogenic nitrogen and phosphorus self-doped TiO2. X-ray diffraction and X-ray photoelectron spectroscopy are conducted to characterize the structure and composition of the samples, which show that they possess single anatase phase, and that nitrogen and phosphorus contained in original soybeans are self-doped into the lattice. UV - Vis spectroscopy displays that N - P -doped TiO2 exhibits an enhanced absorption in the UV - Vis light range and red shift of the absorption edge, compared to undoped TiO2. Furthermore, degradation experiments of rhodamine 6G solution indicate superior photocatalytic activity of N - P - TiO2, of which the degradation rate is 1.4 times that of undoped TiO2. This work may pave a new pathway for synthesizing the discarded biomass and other metal oxides self-doped with biogenic nitrogen and phosphorus.

  19. A multiplex ligation detection assay for the characterization of Salmonella enterica strains

    DEFF Research Database (Denmark)

    Aarts, Henk J.M.; Vos, Pieter; Larsson, Jonas T.;

    2011-01-01

    . The feasibility of the developed assay was verified in a method comparison study with conventional PCR using 16 Salmonella ‘test’ strains comprising eight serovars. Subsequently, the feasibility of the LDR microarray assay was also tested by analyzing 41 strains belonging to 23 serovars. With the exception...

  20. Plaque accumulation and Streptococcus mutans levels around self-ligating bracket clips and elastomeric modules: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Dhaval Fadia

    2015-01-01

    Full Text Available Aim: To determine the effect of two different ligating systems that is, elastomeric modules and self-ligating (SL bracket systems (Smartclip - 3M Unitek with respect to harboring bacterial plaque in fixed orthodontic treatment. Objectives: To assess, evaluate, and compare the amount of plaque accumulation and Streptococcus mutans colonization around elastomeric ligation and SL clips in the smart clip appliance. Materials and Methods: A total of 111 orthodontic patients scheduled for fixed orthodontic treatments were selected for this split maxillary arch study. All the patients were bonded with smart-clip (3M Unitek SL brackets, and the wire was placed into the bracket slots, on the randomly selected hemi arch, elastomeric modules were placed for the study to be conducted. Microbial and periodontal plaque accumulation was recorded at 3-time intervals post ligation. Plaque index-by Silness and Loe, modified Quigely Hein index, bleeding on probing were evaluated, and biofilm was collected from the tooth surface after 30 days and placed in petri dishes containing Mitis Salivarius agar for bacterial culturing. Result: It was observed that the side where ligation was done with elastomeric modules accumulated more plaque and increase in S. mutans colony forming units as compared to the side without external ligation (P < 0.05. Conclusion: Reduced bacterial colonization and better plaque control was seen with SL orthodontic bracket appliance system as compared to conventional ligation method.

  1. Mutational Analysis of Bacterial NAD+-dependent DNA Ligase:Role of Motif Ⅳ in Ligation Catalysis

    Institute of Scientific and Technical Information of China (English)

    Hong FENG

    2007-01-01

    The bacterial DNA ligase as a multiple domain protein is involved in DNA replication, repair and recombination. Its catalysis of ligation can be divided into three steps. To delineate the roles of amino acid residues in motif Ⅳ in ligation catalysis, site-directed mutants were constructed in a bacterial NAD+-dependent DNA ligase from Thermus sp. TAK16D. It was shown that four conserved residues (D286, G287, V289 and K291) in motif Ⅳ had significant roles on the overall ligation. Under single turnover conditions, the observed apparent rates of D286E, G287A, V289I and K291R mutants were clearly reduced compared with that of WT ligase on both match and mismatch nicked substrates. The effects of D286E mutation on overall ligation may not only be ascribed to the third step. The G287A mutation has a major effect on the second step. The effects of V289I and K291R mutation on overall ligation are not on the third step, perhaps other aspects, such as conformation change of ligase protein in ligation catalysis, are involved. Moreover, the amino acid substitutions of above four residues were more sensitive on mismatch nicked substrate, indicating an enhanced ligation fidelity.

  2. Mean age distribution of inorganic soil-nitrogen

    Science.gov (United States)

    Woo, Dong K.; Kumar, Praveen

    2016-07-01

    Excess reactive nitrogen in soils of intensively managed landscapes causes adverse environmental impact, and continues to remain a global concern. Many novel strategies have been developed to provide better management practices and, yet, the problem remains unresolved. The objective of this study is to develop a model to characterize the "age" of inorganic soil-nitrogen (nitrate, and ammonia/ammonium). We use the general theory of age, which provides an assessment of the time elapsed since inorganic nitrogen has been introduced into the soil system. We analyze a corn-corn-soybean rotation, common in the Midwest United States, as an example application. We observe two counter-intuitive results: (1) the mean nitrogen age in the topsoil layer is relatively high; and (2) mean nitrogen age is lower under soybean cultivation compared to corn although no fertilizer is applied for soybean cultivation. The first result can be explained by cation-exchange of ammonium that retards the leaching of nitrogen, resulting in an increase in the mean nitrogen age near the soil surface. The second result arises because the soybean utilizes the nitrogen fertilizer left from the previous year, thereby removing the older nitrogen and reducing mean nitrogen age. Estimating the mean nitrogen age can thus serve as an important tool to disentangle complex nitrogen dynamics by providing a nuanced characterization of the time scales of soil-nitrogen transformation and transport processes.

  3. Stable Isotope Signatures of Carbon and Nitrogen to Characterize Exchange Processes and Their Use for Restoration Projects along the Austrian Danube

    International Nuclear Information System (INIS)

    The size and composition of an organic matter pool and its sources is a fundamental ecosystem property of river networks. River ecosystems are known to receive large amounts of terrestrial organic matter from catchments, still the question is to what extent aquatic sources influence riverine food webs or at least some components of these food webs. To identify different sources and their potential biological availability at the ecosystem level, we propose using stable isotope signatures of carbon and nitrogen and their respective elemental ratios. In this study, we used these parameters to evaluate river restoration measures. The target of the restoration was to improve surface connectivity between the main channel of the Danube downstream from Vienna and a side arm system within a floodplain. Analyses of the natural abundance of stable isotopes revealed that the restored side arm system showed distinct differences in the particulate organic matter pool in relation to hydrological connectivity. At low water levels, aquatic sources dominate in the side arm system, while at high water levels riverine organic matter is the dominating source. At medium connectivity levels aquatic sources also prevail in the side arm, thus an export of bio-available organic matter into the main channel can be expected. Based on these measurements, the increased - but hydrologically controlled - phytoplankton production was assessed and through this information, changes in ecosystem function were evaluated. (author)

  4. Characterization of the effects of nitrogen and hydrogen passivation on SiO2/4H-SiC interface by low temperature conductance measurements

    Science.gov (United States)

    Yiyu, Wang; Zhaoyang, Peng; Huajun, Shen; Chengzhan, Li; Jia, Wu; Yachao, Tang; Yanli, Zhao; Ximing, Chen; Kean, Liu; Xinyu, Liu

    2016-02-01

    We investigate the effects of NO annealing and forming gas (FG) annealing on the electrical properties of a SiO2/SiC interface by low-temperature conductance measurements. With nitrogen passivation, the density of interface states (DIT) is significantly reduced in the entire energy range, and the shift of flatband voltage, ΔVFB, is effectively suppressed to less than 0.4 V. However, very fast states are observed after NO annealing and the response frequencies are higher than 1 MHz at room temperature. After additional FG annealing, the DIT and ΔVFB are further reduced. The values of the DIT decrease to less than 1011 cm-2 eV-1 for the energy range of EC - ET > 0.4 eV. It is suggested that the fast states in shallow energy levels originated from the N atoms accumulating at the interface by NO annealing. Though FG annealing has a limited effect on these shallow traps, hydrogen can terminate the residual Si and C dangling bonds corresponding to traps at deep energy levels and improve the interface quality further. It is indicated that NO annealing in conjunction with FG annealing will be a better post-oxidation process method for high performance SiC MOSFETs. Project supported by the National Natural Science Foundation of China (Nos. 61106080, 61275042) and the National Science and Technology Major Project of the Ministry of Science and Technology of China (No. 2013ZX02305).

  5. Comparison of frictional resistance between self-ligating and conventional brackets tied with elastomeric and metal ligature in orthodontic archwires

    OpenAIRE

    Vanessa Vieira Leite; Murilo Baena Lopes; Alcides Gonini Júnior; Marcio Rodrigues de Almeida; Sandra Kiss Moura; Renato Rodrigues de Almeida

    2014-01-01

    OBJECTIVE: To compare the frictional resistance between self-ligating and conventional brackets tied to different types of wire. MATERIAL AND METHODS : Abzil Kirium Capelozza (Pattern I) and Easy Clip (Roth prescription) incisor brackets were used. An elastomeric ligature or a ligating wire 0.10-in was used to ligate the wire to the Abzil bracket. Three types of orthodontic archwire alloys were assessed: 0.016-in NiTi wire, 0.016 x 0.021-in NiTi wire and 0.019 x 0.025-in steel wire. Ten obser...

  6. Evaluation of mesenteric lymphangiography and thoracic duct ligation in cats with chylothorax: 19 cases (1987-1992)

    International Nuclear Information System (INIS)

    Mesenteric lymphangiography and thoracic duct ligation were performedon 19 cats with chylothorax between 1987 to 1992. Chylothorax was diagnosed on the basis of detection of chylomicrons in the pleural effusion or determination of a cholesterol concentration:triglyceride concentration ratio of 12 months after surgery. Four cats died between 2 and 13 days after thoracic duct ligation, but pleural effusion had resolved in 3 of these 4 cats at the time of death. Five cats were euthanatized 8 to 36 days after surgery because of persistent chylous effusion after thoracic duct ligation

  7. Asymmetric transcriptomic signatures between the cob and florets in the maize ear under optimal- and low-nitrogen conditions at silking, and functional characterization of amino acid transporters ZmAAP4 and ZmVAAT3.

    Science.gov (United States)

    Pan, Xiaoying; Hasan, Md Mahmudul; Li, Yanqiang; Liao, Chengsong; Zheng, Hongyan; Liu, Renyi; Li, Xuexian

    2015-10-01

    Coordinated functioning of the cob and florets of the maize ear confers grain yield. The cob is critical for carbon partitioning and assimilated nitrogen (N) supply for grain development. However, molecular recognition of the cob and peripheral florets, characterization of genes mediating translocation of N assimilates, and responses of these two tissues to low N (LN) remain elusive. Transcriptional profiling of the ear of a maize hybrid at silking in the field revealed 1864 differentially expressed genes between the cob and florets, with 1314 genes up-regulated in the cob and 550 genes up-regulated in florets. The cob was characterized by striking enrichment of genes that are involved in carbon/N transport and metabolism, consistent with the physiological role of the cob in carbon/N storage and transfer during ear development. The florets were characterized by enrichment of hormone signalling components and development related genes. We next examined the response of the cob and florets to LN stress. LN caused differential expression of 588 genes in the cob and only 195 genes in the florets, indicating that the cob dominated the response of the ear to LN at the transcriptional level. LN caused comprehensive alterations such as carbon/N metabolism or partitioning, hormone signalling and protein phosphorylation in terms of gene expression in the cob and/or florets. Fourteen genes responsive specifically to LN provided potential molecular markers for N-efficient maize breeding. We further functionally characterized two newly identified broad-spectrum amino acid transporters, ZmAAP4 and ZmVAAT3, that showed distinct expression patterns in the cob and florets and potentially important roles in amino-N mobilization in the ear. While both proteins could transport various amino acids into yeast or Arabidopsis cells, ZmAAP4 appeared to have higher efficiencies than ZmVAAT3 in transporting seven out of 22 examined amino acids. PMID:26136266

  8. Sortase-mediated ligation of PsaE-modified photosystem I from Synechocystis sp. PCC 6803 to a conductive surface for enhanced photocurrent production on a gold electrode.

    Science.gov (United States)

    Le, Rosemary K; Raeeszadeh-Sarmazdeh, Maryam; Boder, Eric T; Frymier, Paul D

    2015-01-27

    Sortase-mediated ligation was used to attach the photosystem I (PSI) complex from Synechocystis sp. PCC 6803 in a preferential orientation to enhance photoinduced electron flow to a conductive gold surface. Ideally, this method can result in a uniform monolayer of protein, covalently bound unidirectionally to the electrode surface. The exposed C-termini of the psaE subunits of the PSI trimer were targeted to contain an LPETG-sortase recognition sequence to increase noncompeting electron transfer by uniformly orienting the PSI stromal side proximal to the surface. Surface characterization with atomic force microscopy suggested that monolayer formation and optimal surface coverage occurred when the gold surfaces were incubated with peptide at 100 to 500 μM concentrations. When photochronoamperometry with potassium ferrocyanide and ferricyanide as redox mediators was used, photocurrents in the range of 100 to 200 nA/cm(2) were produced, which is an improvement over other attachment techniques for photosystem monolayers that produce approximately 100 nA/cm(2) or less. This work demonstrated that sortase-mediated ligation aided in the control of PSI orientation on modified gold surfaces with a distribution of 94% stromal side proximal and 6% lumenal side proximal to the surface for current-producing PSI.

  9. Process characterization and influence of alternative carbon sources and carbon-to-nitrogen ratio on organic acid production by Aspergillus oryzae DSM1863.

    Science.gov (United States)

    Ochsenreither, Katrin; Fischer, Christian; Neumann, Anke; Syldatk, Christoph

    2014-06-01

    L-Malic acid and fumaric acid are C4 dicarboxylic organic acids and considered as promising chemical building blocks. They can be applied as food preservatives and acidulants in rust removal and as polymerization starter units. Molds of the genus Aspergillus are able to produce malic acid in large quantities from glucose and other carbon sources. In order to enhance the production potential of Aspergillus oryzae DSM 1863, production and consumption rates in an established bioreactor batch-process based on glucose were determined. At 35 °C, up to 42 g/L malic acid was produced in a 168-h batch process with fumaric acid as a by-product. In prolonged shaking flask experiments (353 h), the suitability of the alternative carbon sources xylose and glycerol at a carbon-to-nitrogen (C/N) ratio of 200:1 and the influence of different C/N ratios in glucose cultivations were tested. When using glucose, 58.2 g/L malic acid and 4.2 g/L fumaric acid were produced. When applying xylose or glycerol, both organic acids are produced but the formation of malic acid decreased to 45.4 and 39.4 g/L, respectively. Whereas the fumaric acid concentration was not significantly altered when cultivating with xylose (4.5 g/L), it is clearly enhanced by using glycerol (9.3 g/L). When using glucose as a carbon source, an increase or decrease of the C/N ratio did not influence malic acid production but had an enormous influence on fumaric acid production. The highest fumaric acid concentrations were determined at the highest C/N ratio (300:1, 8.44 g/L) and lowest at the lowest C/N ratio (100:1, 0.7 g/L).

  10. Enzyme-free amplified detection of DNA by an autonomous ligation DNAzyme machinery.

    Science.gov (United States)

    Wang, Fuan; Elbaz, Johann; Willner, Itamar

    2012-03-28

    The Zn(2+)-dependent ligation DNAzyme is implemented as a biocatalyst for the amplified detection of a target DNA by the autonomous replication of a nucleic acid reporter unit that is generated by the catalyzed ligation process. The reporter units enhance the formation of active DNAzyme units, thus leading to the isothermal autocatalytic formation of the reporter elements. The system was further developed and applied for the amplified detection of Tay-Sachs genetic disorder mutant, with a detection limit of 1.0 × 10(-11) M. Besides providing a versatile paradigm for the amplified detection of DNA, the system reveals a new, enzyme-free, isothermal, autocatalytic mechanism that introduces means for effective programmed synthesis. PMID:22404383

  11. Ultrasensitive monitoring of ribozyme cleavage product using molecular-beacon-ligation system

    Institute of Scientific and Technical Information of China (English)

    MENG XiangXian; TANG ZhiWen; WANG KeMin; TAN WeiHong; YANG XiaoHai; LI Jun; GUO QiuPing

    2007-01-01

    This paper reports a new approach to detect ribozyme cleavage product based on the molecular- beacon-ligation system. The molecular beacon, designed in such a way that one-half of its loop is complementary to ribozyme cleavage product, is used to monitor ligation process of RNA/DNA complex in a homogeneous solution and to convert directly cleavage product information into fluorescence signal. The method need not label ribozyme and ribozyme substrate, which is fast, simple and ultrasensitive for detection of cleavage product. Detection limit of the assay is 0.05 nmol/L. The cleavage product of hammerhead ribozyme against hepatitis C virus RNA (HCV-RNA) was detected perfectly based on this assay. Owing to its ultrasensitivity, excellent specificity, convenience and fidelity, this method might hold out great promise in ribozyme reaction and ribozyme gene therapy.

  12. Actual versus theoretical torsional play in conventional and self-ligating bracket systems

    DEFF Research Database (Denmark)

    Dalstra, Michel; Eriksen, Henrik; Bergamini, Chiara;

    2015-01-01

    Abstract Objective: The aim of this study was to assess the amount of torsional play in 32 commercially available self-ligating and conventional 0·018-inch and 0·022-inch bracket systems in relation to 0·017×0·022-inch and 0·019×0·025-inch stainless steel wires, respectively, and compare the resu......Abstract Objective: The aim of this study was to assess the amount of torsional play in 32 commercially available self-ligating and conventional 0·018-inch and 0·022-inch bracket systems in relation to 0·017×0·022-inch and 0·019×0·025-inch stainless steel wires, respectively, and compare...

  13. Ligation-anchored PCR unveils immune repertoire of TCR-beta from whole blood

    OpenAIRE

    Gao, Fan; Kai WANG

    2015-01-01

    Background As one of the genetic mechanisms for adaptive immunity, V(D)J recombination generates an enormous repertoire of T-cell receptors (TCRs). With the development of high-throughput sequencing techniques, systematic exploration of V(D)J recombination becomes possible. Multiplex PCR has been previously developed to assay immune repertoire; however, the use of primer pools leads to inherent biases in target amplification. In our study, we developed a “single-primer" ligation-anchored PCR ...

  14. The terminal 5′ phosphate and proximate phosphorothioate promote ligation-independent cloning

    OpenAIRE

    Liu, Xi-Peng; LIU, JIAN-HUA

    2010-01-01

    Function studies of many proteins are waited to develop after genome sequencing. High-throughout technology of gene cloning will strongly promote proteins' function studies. Here we describe a ligation-independent cloning (LIC) method, which is based on the amplification of target gene and linear vector by PCR using phosphorothioate-modified primers and the digestion of PCR products by λ exonuclease. The phosphorothioate inhibits the digestion and results in the generation of 3′ overhangs, wh...

  15. Evaluation of the Friction of Self-Ligating and Conventional Bracket Systems

    OpenAIRE

    Tecco, Simona; Di Iorio, Donato; Nucera, Riccardo; Di Bisceglie, Beatrice; Cordasco, Giancarlo; Festa, Felice

    2011-01-01

    Objectives: This in vitro study evaluated the friction (F) generated by aligned stainless steel (SS) conventional brackets, self-ligating Damon MX© brackets (SDS Ormco, Glendora, California, USA), Time3© brackets (American Orthodontics, Sheboygan, Wisconsin, USA), Vision LP© brackets (American Orthodontics), and low-friction Slide© ligatures (Leone, Firenze, Italy) coupled with various SS, nickel-titanium (NiTi), and beta-titanium (TMA) archwires. Methods: All brackets had a 0.022-inch slot, ...

  16. Mandibular dental arch changes associated with treatment of crowding using self-ligating and conventional brackets.

    Science.gov (United States)

    Pandis, Nicholas; Polychronopoulou, Argy; Makou, Margarita; Eliades, Theodore

    2010-06-01

    The purpose of this study was to investigate the effect of treatment of mandibular crowding with self-ligating and conventional brackets on dental arch variables. Fifty-six patients were selected from a pool of subjects satisfying the following inclusion criteria: non-extraction treatment in the mandibular or maxillary arches, eruption of all mandibular teeth, no spaces and an irregularity index greater than 2 mm in the mandibular arch, and no adjunct treatment such as etxra- or intraoral appliances. The patients were assigned to two groups: one group received treatment with the self-ligating bracket and the other with a conventional edgewise appliance, both with a 0.022 inch slot. Lateral cephalometric radiographs obtained at the beginning (T1) and end (T2) of treatment were used to assess the alteration in mandibular incisor inclination, and measurements of intercanine and intermolar widths were made on dental casts to investigate changes associated with the correction. The results were analysed with bivariate and multivariate linear regression analysis in order to examine the effect of the bracket systems on arch width or lower incisor inclination, adjusting for the confounding effect of demographic and clinical characteristics. An alignment-induced increase in the proclination of the mandibular incisors was observed for both groups; no difference was identified between self-ligating and conventional brackets with respect to this parameter. Likewise, an increase in intercanine and intermolar widths was noted for both bracket groups; the self-ligating group showed a higher intermolar width increase than the conventional group, whereas the amount of crowding and Angle classification were not significant predictors of post-treatment intermolar width. PMID:19959610

  17. Comparison between Ultroid and Rubber Band Ligation in Treatment of Internal Hemorrhoids

    Directory of Open Access Journals (Sweden)

    Rasoul Azizi

    2010-11-01

    Full Text Available "nHemorrhoid is one of the most common surgical diseases and different methods are available for its treatment. This study is a comparison between two methods of treatment of internal hemorrhoid, Monopolar low voltage instrument (Ultroid and Rubber Band Ligation. This method has been carried out prospectively in which 50 patients who were treated with rubber band ligation and 50 patients with Ultroid were compared according to the incidence of complications, post-operative pain and treatment response. According to this study complete success rate with Ultroid was 82% and partial success rate was 10% and no response to treatment was seen in 8%. In Rubber Band method the complete response rate was 94% (P=0.2. With Ultroid, 74% of patient reported no postoperative pain, 24% reported mild and moderate pain and 2% of patients complained of severe pain. With Rubber band ligation, 72% of patients reported no post-operative pain, 26% reported mild and moderate pain and 1% complained of severe pain (P=0.00. Rubber Band ligation and Ultroid are both considered as outpatient procedures for treatment of hemorrhoids. Both methods are mostly used for grade 1, 2 and sometime grade 3 hemorrhoids. In Ultroid method the operator is required to hold the probe for a period of time, and in most cases, the surgeon should spend between 20-25 minutes for the coagulation of three piles. Some surgeons do not have patience for this modality of internal hemorrhoid treatment. In this study we achieved acceptable results comparable with those of other techniques.

  18. Patent ductus arteriosus ligation alters pulmonary gene expression in preterm baboons

    OpenAIRE

    Waleh, Nahid; McCurnin, Donald C.; Yoder, Bradley A.; Shaul, Philip W.; Clyman, Ronald I.

    2011-01-01

    Ibuprofen-induced ductus closure improves pulmonary mechanics and increases alveolar surface area in premature baboons compared with baboons with a persistent patent ductus arteriosus (PDA). Ibuprofen-treatment has no effect on the expression of genes that regulate pulmonary inflammation but does increase the expression of alpha-ENaC (the transepithelial sodium channel that is critical for alveolar water clearance). Although ligation eliminates the PDA, it does not improve pulmonary mechanics...

  19. Autogenous Transplantation of Duct Ligated Pancreas: A Functional and Histological Study

    Directory of Open Access Journals (Sweden)

    Page BJ

    2004-03-01

    Full Text Available CONTEXT: The use of foetal tissue is an emotive issue and attempts are being made to find suitable alternative replacements. A duct ligated pancreas resembles day 16-17 post-coitum foetal pancreas tissue, both being predominantly endocrine structures. OBJECTIVE: The aim of this study was to quantify the metabolic changes occurring in chemically induced diabetic rats over a 30 day period following transplantation of duct ligated tissue beneath the renal capsule. SETTING: Thirty normal Sprague-Dawley laboratory rats. DESIGN: The rats were grouped as transplant recipients (A, untreated diabetic (B, untreated normal (C, sham operated controls (D and donors of duct ligated pancreatic tissue (E. INTERVENTIONS: Groups A and B received 60 mg/kg streptozotocin via a tail vein rendering them diabetic. Groups D and E underwent mid-line laparotomy under general anaesthesia with pancreatic duct ligation procedures performed on E in addition. MAIN OUTCOME MEASURES: Blood glucose was monitored daily in Groups A, B, C and D, and exogenous insulin was administered in Groups A and B as required. Glucose tolerance tests were performed on day 3.5 and after 30 days in Groups A (just prior to unilateral nephrectomy, B, C and D. In addition, in Group A, they were repeated one week after the removal of the grafted tissue. The removed grafts were processed for histological examination. RESULTS: The metabolic profile of the transplant recipients compared favourably with that of normal animals. CONCLUSION: A chemically or mechanically manipulated pancreas may respond to exogenous insulin therapy by undergoing some degree of regeneration or owing to the pluripotent stem cells thought to reside in the pancreas. Although insulin positive tissue was evident at the graft site, morphometric assessment, however, found no significant increase in the insulin secreting tissue in the pancreas compared to the untreated diabetic controls.

  20. An enhanced method for sequence walking and paralog mining: TOPO® Vector-Ligation PCR

    Directory of Open Access Journals (Sweden)

    Davis Thomas M

    2010-03-01

    Full Text Available Abstract Background Although technological advances allow for the economical acquisition of whole genome sequences, many organisms' genomes remain unsequenced, and fully sequenced genomes may contain gaps. Researchers reliant upon partial genomic or heterologous sequence information require methods for obtaining unknown sequences from loci of interest. Various PCR based techniques are available for sequence walking - i.e., the acquisition of unknown DNA sequence adjacent to known sequence. Many such methods require rigid, elaborate protocols and/or impose narrowly confined options in the choice of restriction enzymes for necessary genomic digests. We describe a new method, TOPO® Vector-Ligation PCR (or TVL-PCR that innovatively integrates available tools and familiar concepts to offer advantages as a means of both targeted sequence walking and paralog mining. Findings TVL-PCR exploits the ligation efficiency of the pCR®4-TOPO® (Invitrogen, Carlsbad, California vector system to capture fragments of unknown sequence by creating chimeric molecules containing defined priming sites at both ends. Initially, restriction enzyme-digested genomic DNA is end-repaired to create 3' adenosine overhangs and is then ligated to pCR4-TOPO vectors. The ligation product pool is used directly as a template for nested PCR, using specific primers to target orthologous sequences, or degenerate primers to enable capture of paralogous gene family members. We demonstrated the efficacy of this method by capturing entire coding and partial promoter sequences of several strawberry Superman-like genes. Conclusions TVL-PCR is a convenient and efficient method for DNA sequence walking and paralog mining that is applicable to any organism for which relevant DNA sequence is available as a basis for primer design.

  1. Are self-ligating brackets related to less formation of Streptococcus mutans colonies? A systematic review

    Directory of Open Access Journals (Sweden)

    Leonard Euler Andrade Gomes do Nascimento

    2014-01-01

    Full Text Available OBJECTIVE: To verify, by means of a systematic review, whether the design of brackets (conventional or self-ligating influences adhesion and formation of Streptococcus mutans colonies. METHODS: Search strategy: four databases (Cochrane Central Register of Controlled Trials, Ovid ALL EMB Reviews, PubMed and BIREME were selected to search relevant articles covering the period from January 1965 to December 2012. Selection Criteria: in first consensus by reading the title and abstract. The full text was obtained from publications that met the inclusion criteria. Data collection and analysis: Two reviewers independently extracted data using the keywords: conventional, self-ligating, biofilm, Streptococcus mutans, and systematic review; and independently evaluated the quality of the studies. In case of divergence, the technique of consensus was adopted. RESULTS: The search strategy resulted in 1,401 articles. The classification of scientific relevance revealed the high quality of the 6 eligible articles of which outcomes were not unanimous in reporting not only the influence of the design of the brackets (conventional or self-ligating over adhesion and formation of colonies of Streptococcus mutans, but also that other factors such as the quality of the bracket type, the level of individual oral hygiene, bonding and age may have greater influence. Statistical analysis was not feasible because of the heterogeneous methodological design. CONCLUSIONS: Within the limitations of this study, it was concluded that there is no evidence for a possible influence of the design of the brackets (conventional or self-ligating over colony formation and adhesion of Streptococcus mutans.

  2. Transversal changes in dental arches from non-extraction treatment with self ligating brackets

    OpenAIRE

    Liliana Avila Maltagliati; Yasushi Inoue Myiahira; Liana Fattori; Leopoldino Capelozza Filho; Mauricio Cardoso

    2013-01-01

    OBJECTIVE: The present study aimed at analyzing, with the use of dental casts, the transverse changes of the upper and lower dental arches, after non-extraction orthodontic treatment, with self-ligating brackets. METHODS: The sample comprised 29 patients, all presenting Class I malocclusion with upper and lower crowding of at least 4 mm and treated only with a fixed appliance, without stripping, extraction or distalization. The dental casts were obtained before and after leveling with 0.019 x...

  3. Banding ligation versus beta-blockers for primary prevention in oesophageal varices in adults

    DEFF Research Database (Denmark)

    Gluud, Lise Lotte; Krag, Aleksander

    2012-01-01

    Non-selective beta-blockers are used as a first-line treatment for primary prevention in patients with medium- to high-risk oesophageal varices. The effect of non-selective beta-blockers on mortality is debated and many patients experience adverse events. Trials on banding ligation versus non......-selective beta-blockers for patients with oesophageal varices and no history of bleeding have reached equivocal results....

  4. Ethanolic extract of Aloe vera ameliorates sciatic nerve ligation induced neuropathic pain

    OpenAIRE

    Swetha Kanyadhara; Sujatha Dodoala; Sunitha Sampathi; Priyanka Punuru; Gopichand Chinta

    2014-01-01

    Background: Aloe vera is being used since ages by human kind for treating various ailments including various inflammatory conditions, but scientific validation has not been done for analgesic activity against neuropathic pain. Objective: The current study was designed to systematically evaluate the therapeutic potential of the ethanolic extract of A. vera (EEAV) against sciatic nerve ligation (SCNL) induced neuropathic pain. Materials and Methods: Nociceptive threshold of EEAV against...

  5. Pulmonary Functions After Injection Sclerotherapy Of Esophageal Varices & After Band Ligation

    OpenAIRE

    Mohamed A. Metwally*, Ahmad Abdelsadek Mohammad,**Galal A. Moawad,*.

    2013-01-01

    Aim of the study: To study changes in pulmonary function tests after esophageal variceal injection sclerotherapy in comparison to changes after esophageal variceal band ligation.Patients & methods:This study was designed as non randomized controlled study. Thirty patients with hepatic cirrhosis & portal hypertension who were admitted to Hepatology, Gastroenterology and Infectious Diseases department , Benha university hospital for elective esophageal variceal therapy (secondary prophylaxis) ...

  6. Ligation of Left Renal Vein for Spontaneous Splenorenal Shunt to Prevent Portal Hypoperfusion after Orthotopic Liver Transplantation

    Directory of Open Access Journals (Sweden)

    Lampros Kousoulas

    2013-01-01

    Full Text Available We report a case of recovered portal flow by ligation of the left renal vein on the first postoperative day after orthotopic liver transplantation of a 54-year-old female with alcoholic liver cirrhosis, chronic kidney failure, and spontaneous splenorenal shunt. After reperfusion, Doppler ultrasonography showed almost total diversion of the portal flow into the existing splenorenal shunt, but because of severe coagulopathy and diffuse bleeding, ligation of the shunt was not attempted. A programmed relaparotomy was performed on the first postoperative day, and the left renal vein was ligated just to the left of the inferior vena cava. Portal flows subsequently increased to 37 cm/sec, and the patient presented a good and stable liver function. We conclude that patients with known preoperative splenorenal shunts should be closely monitored, and if the portal flow becomes insufficient, ligation of the left renal vein should be attempted in order to optimize the portal perfusion of the liver.

  7. 微污染黄浦江水溶解性有机氮的分子组成特性分析%Characterization of Dissolved Organic Nitrogen in Micro-polluted Huangpu River Water

    Institute of Scientific and Technical Information of China (English)

    荣蓉; 徐斌; 林琳; 胡晨燕; 夏圣骥; 高乃云; 叶涛; 李大鹏

    2013-01-01

    Dissolved organic matters in micro-polluted raw water from Huangpu River were concentrated and separated using reverse osmosis process and ion exchange technology. The molecular weight distribution and hydrophilic-hydrophobic characteristics of dissolved organic nitrogen ( DON) were analyzed , and the composition of DON was characterized by hydrogen isotope nuclear magnetic resonance, three-dimensional fluorescence spectrum and Fourier transform infrared spectroscopy. The results showed that DON in the raw water was mainly composed of fractions with small molecular weight, and the average molecular weight of DON was slightly higher than that of DOC and UV254. Neutral hydrophilic components showed the highest percentage of organic nitrogen, which was obviously higher than that of DOC and UV254. Protein-like organies, amino compounds and aromatic compounds were the main contributions to DON in the raw water. Moreover, DON also consisted of nitrogen-hydrogen compounds, fatty hydrocarbon compounds, saturated hydrocarbons and so on.%以微污染黄浦江原水作为研究对象,采用反渗透工艺和离子交换技术对水中溶解性有机物进行浓缩和分离,分析了溶解性有机氮(DON)的分子质量和亲、疏水性分布规律,并采用氢同位素的核磁共振法、三维荧光光谱分析法和傅里叶变换红外光谱法表征了DON的组成.结果表明,原水中的DON以小分子为主,其平均分子质量略大于以DOC和UV254表征的有机物;DON的中性亲水性组分所占比例最高,明显大于DOC和UV254;类蛋白类有机物、胺基类、芳香类化合物对DON的贡献较大;原水中的DON包含有氮氢类化合物、脂肪烃有机物、饱和碳氢化合物等.

  8. Antioxidant Effect of Sepia Ink Extract on Extrahepatic Cholestasis Induced by Bile Duct Ligation in Rats

    Institute of Scientific and Technical Information of China (English)

    Hanan Saleh; Amel M Soliman; Ayman S Mohamed; Mohamed-Assem S Marie

    2015-01-01

    Objective The aim of our study was to assess the complications of hepatic fibrosis associated with bile duct ligation and the potential curative role of sepia ink extract in hepatic damage induced by bile duct ligation. Methods Rattus norvegicus rats were divided into 3 groups: Sham-operated group, model rats that underwent common bile duct ligation (BDL), and BDL rats treated orally with sepia ink extract (200 mg/kg body weight) for 7, 14, and 28 d after BDL. Results There was a significant reduction in hepatic enzymes, ALP, GGT, bilirubin levels, and oxidative stress in the BDL group after treatment with sepia ink extract. Collagen deposition reduced after sepia ink extract treatment as compared to BDL groups, suggesting that the liver was repaired. Histopathological examination of liver treated with sepia ink extract showed moderate degeneration in the hepatic architecture and mild degeneration in hepatocytes as compared to BDL groups. Conclusion Sepia ink extract provides a curative effect and an antioxidant capacity on BDL rats and could ameliorate the complications of liver cholestasis.

  9. Experiments to optimize enzyme substitution therapy in pancreatic duct-ligated pigs.

    Science.gov (United States)

    Kammlott, E; Karthoff, J; Stemme, K; Gregory, P; Kamphues, J

    2005-01-01

    Ligation of the pancreatic duct in pigs leads to severe maldigestion and malabsorption of crude nutrients. Supplementation with 24 capsules of Creon (Solvay Pharmaceuticals GmbH, Hannover, Germany) per meal led to an increased digestibility of crude nutrients. With regard to optimization of the treatment of EPI no essential improvements can be achieved by adding omeprazol or lecithin to the diet. In pancreatic duct-ligated pigs the isolated addition of omeprazol led to an increase of the pre-caecal digestibility of crude fat and organic matter. With additional enzyme substitution, the application of omeprazol did not result in an improved fat digestibility. Isolated addition of lecithin to the diet resulted in a reduced total digestibility of crude fat. Offering the diet twice a day and using a higher frequency of enzyme applications (four or six instead of only two applications) had no effects on the digestibilty of crude fat or organic matter. According to the observations in pancreatic duct-ligated pigs, the addition of missing enzymes to the diet led to the best treatment results in EPI. Administration of omeprazol or a higher feeding frequency as well as the application of enzymes in small proportion of the whole meal or dosages given consecutively over the day showed no advantages. Furthermore, the present study suggests that the addition of lecithin cannot be recommended in EPI, when given diets with butter as the predominant fat source as in human dietetics. PMID:15787979

  10. Psychosocial implications of tubal ligation in a rural health district: A phenomenological study

    Directory of Open Access Journals (Sweden)

    Lutala Prosper M

    2011-12-01

    Full Text Available Abstract Background Tubal ligation is the most popular family planning method worldwide. While its benefits, such as effectiveness in protecting against pregnancies, minimal need for long-term follow-up and low side-effects profile are well documented, it has many reported complications. However, to date, these complications have not been described by residents in Congo. Therefore, the study aimed at exploring the experience of women who had undergone tubal ligation, focusing on perceptions of physical, psychological and contextual experiences of participants. Methods This qualitative study used a semi-structured questionnaire in a phenomenological paradigm to collect data. Fifteen participants were purposefully selected among sterilized women who had a ligation procedure performed, were aged between 30 and 40 years, and were living within the catchment area of the district hospital. Data were collected by two registered nurses, tape-recorded, and transcribed verbatim. Reading and re-reading cut and paste techniques, and integration were used to establish codes, categories, themes, and description. Results Diverse and sometimes opposite changes in somatic symptoms, psychological symptoms, productivity, ecological relationships, doctor-client relationships, ethical issues, and change of life style were the major problem domains. Conclusions Clients reported conflicting experiences in several areas of their lives after tubal sterilization. Management, including awareness of the particular features of the client, is needed to decrease the likelihood of psychosocial morbidity and/or to select clients in need of sterilization.

  11. Arterial Ligation for Infected Femoral Psuedo-Aneurysm in Drug Injecting Abusers

    Directory of Open Access Journals (Sweden)

    Mohammadzade Mohammad Ali

    2009-10-01

    Full Text Available Pseudo-aneurysm of the femoral artery is the most common arterial complication in drug injecting abusers. Scholars in vascular surgery have published debating statements regarding techniques of successful surgical management during last two decades. We present the results of simple arterial ligation in a series of 32 patients presenting with infected femoral pseudo-aneurysm. Most of the patients were males (89%. Young persons in the age group of 15-44 years were mostly affected. Site of lesion included common femoral artery in 65% , superficial femoral artery 28% and at bifurcation 6.2%. celulitis in 14 (53%, abscess & "ncelulitis in 6 (19%, necrosing fasciitis in 2 (6.2% and vascular abscess in 7 (22% cases were the forms of associated local infection. There was no hemorrhage, vascular thrombosis, amputation, or mortality. Claudicating were the only complications identified in 2 patients with Tripe ligation. Ligation is the optimal management for infected pseudo-aneurysms because it is easy, cost-effective, and safe. Early reconstruction is not recommended, since there is an extended infection in the location of the pseudo-aneurysm.

  12. Comparison of Ligation-Mediated PCR Methods in Differentiation of Mycobacterium tuberculosis Strains

    Directory of Open Access Journals (Sweden)

    Anna Zaczek

    2014-01-01

    Full Text Available Fast and inexpensive identification of epidemiological links between limited number of Mycobacterium tuberculosis strains is required to initially evaluate hospital outbreaks, laboratory crosscontaminations, and family or small community transmissions. The ligation-mediated PCR methods (LM-PCR appear sufficiently discriminative and reproducible to be considered as a good candidate for such initial, epidemiological analysis. Here, we compared the discriminative power of the recently developed in our laboratory fast ligation amplification polymorphism (FLAP method with fast ligation-mediated PCR (FLiP. Verification of the results was based on analyzing a set of reference strains and RFLP-IS6110 typing. The HGDI value was very similar for both LM-PCR methods and RFLP-IS6110 typing. However, only 52% of strains were correspondingly grouped by both FLiP and FLAP methods. Differentiation by FLAP method demonstrated a limited similarity to IS6110-RFLP (37,7%. As much as 78,7% of strains were grouped identically when differentiated by FLiP and IS6110-RFLP methods. The analysis differentiated 31, 35, and 36 groups when using FLAP, FLiP, and RFLP-IS6110 methods, respectively.

  13. Self-ligating versus Invisalign: analysis of dento-alveolar effects

    Science.gov (United States)

    Pavoni, Chiara; Lione, Roberta; Laganà, Giuseppina; Cozza, Paola

    2011-01-01

    Summary Aim The aim of this study was to evaluate the changes in the transverse dimension and the perimeter of the maxillary arch produced by low friction self-ligating brackets TIME 3 compared to the Invisalign technique. Materials and methods Both the self-ligating sample and the Invisalign group were composed of 20 subjects, evaluated at the beginning (T0) and at the completion of therapy (T1). All subjects presented a Class I malocclusion with mild crowding in a permanent dentition, without craniofacial anomalies, missing teeth or a history of orthodontic treatment. Dento-alveolar measurements were made on the maxillary dental casts at T0 and T1. Significant differences between the treated groups were assessed with Independent Samples t test (pInvisalign group were recorded for CWC, FPWF, FPWL, SPWF, SPWL, and AP measurements. No significant changes were found for CWL, MWF, MWL, and AD values. There was not a statistically significant difference between the treatment durations of the groups: 1.8 years for both patients. These data suggest that Invisalign treatment cannot be somewhat faster than fixed appliances. Moreover the final occlusion might not be as ideal. Conclusions The low fiction self-ligating system produced statistically significant different outcomes in the transverse dento-alveolar width and the perimeter of the maxillary arch during treatment when compared to Invisalign tecnique. PMID:22238719

  14. pH-degradable imidazoquinoline-ligated nanogels for lymph node-focused immune activation.

    Science.gov (United States)

    Nuhn, Lutz; Vanparijs, Nane; De Beuckelaer, Ans; Lybaert, Lien; Verstraete, Glenn; Deswarte, Kim; Lienenklaus, Stefan; Shukla, Nikunj M; Salyer, Alex C D; Lambrecht, Bart N; Grooten, Johan; David, Sunil A; De Koker, Stefaan; De Geest, Bruno G

    2016-07-19

    Agonists of Toll-like receptors (TLRs) are potent activators of the innate immune system and hold promise as vaccine adjuvant and for anticancer immunotherapy. Unfortunately, in soluble form they readily enter systemic circulation and cause systemic inflammatory toxicity. Here we demonstrate that by covalent ligation of a small-molecule imidazoquinoline-based TLR7/8 agonist to 50-nm-sized degradable polymeric nanogels the potency of the agonist to activate TLR7/8 in in vitro cultured dendritic cells is largely retained. Importantly, imidazoquinoline-ligated nanogels focused the in vivo immune activation on the draining lymph nodes while dramatically reducing systemic inflammation. Mechanistic studies revealed a prevalent passive diffusion of the nanogels to the draining lymph node. Moreover, immunization studies in mice have shown that relative to soluble TLR7/8 agonist, imidazoquinoline-ligated nanogels induce superior antibody and T-cell responses against a tuberculosis antigen. This approach opens possibilities to enhance the therapeutic benefit of small-molecule TLR agonist for a variety of applications. PMID:27382168

  15. Dentoalveolar mandibular changes with self-ligating versus conventional bracket systems: A CBCT and dental cast study

    OpenAIRE

    Marcio Rodrigues de Almeida; Cristina Futagami; Ana Cláudia de Castro Ferreira Conti; Paula Vanessa Pedron Oltramari-Navarro; Ricardo de Lima Navarro

    2015-01-01

    OBJECTIVE: The aim of the present study was to compare dentoalveolar changes in mandibular arch, regarding transversal measures and buccal bone thickness, in patients undergoing the initial phase of orthodontic treatment with self-ligating or conventional bracket systems. METHODS: A sample of 25 patients requiring orthodontic treatment was assessed based on the bracket type. Group 1 comprised 13 patients bonded with 0.022-in self-ligating brackets (SLB). Group 2 included 12 patients bonded wi...

  16. Universal strategies for the DNA-encoding of libraries of small molecules using the chemical ligation of oligonucleotide tags

    OpenAIRE

    LITOVCHICK, ALEXANDER; Clark, Matthew A.; Keefe, Anthony D

    2014-01-01

    The affinity-mediated selection of large libraries of DNA-encoded small molecules is increasingly being used to initiate drug discovery programs. We present universal methods for the encoding of such libraries using the chemical ligation of oligonucleotides. These methods may be used to record the chemical history of individual library members during combinatorial synthesis processes. We demonstrate three different chemical ligation methods as examples of information recording processes (writ...

  17. Difference in left renal vein pressure: an indicator for free of reconstruction after ligation in retroperitoneal tumor patients

    OpenAIRE

    Chengli Miao; Mengmeng Xiao; Tengyan Li; Gang Liu; Xing Liu; Yue Kong; Chenghua Luo

    2015-01-01

    We hypothesized that the left renal vein pressure difference (ΔP) before and after the ligation can serve as an objective indicator for free of reconstruction after resection of a retroperitoneal tumor with renal segment of inferior vena cava and right kidney. After established a model of left renal vein compression, 45 miniature pigs were operated on experimental procedures including renal segment of inferior vena cava resection, right nephrectomy, and left renal vein ligation. The ΔPs of le...

  18. AB154. Effect of early adrenal vein ligation on blood pressure and catecholamine fluctuation during laparoscopic adrenalectomy for pheochromocytoma

    OpenAIRE

    Wu, Guojun; Yu, Chuigong; Yu, Lei; Zhang, Geng; Yang, Lijun; Lin, Yuanjian

    2014-01-01

    Objective To find out whether previous control of the adrenal vein is a crucial procedure in laparoscopic adrenalectomy for pheochromocytoma. Method From January 2000 to December 2010, 114 pheochromocytoma patients underwent laparoscopic adrenalectomy through transperitoneal or retroperitoneal approach. All the 114 patients were divided into two groups randomly (group 1, dissection after ligation; group 2, dissection before ligation). Blood samples to dose catecholamines using high performanc...

  19. An efficient on-column expressed protein ligation strategy: Application to segmental triple labeling of human apolipoprotein E3

    OpenAIRE

    Zhao, Wentao; Zhang, Yonghong; Cui, Chunxian; Li, Qianqian; Wang, Jianjun

    2008-01-01

    Expressed protein ligation (EPL) is an intein-based approach that has been used for protein engineering and biophysical studies of protein structures. One major problem of the EPL is the low yield of final ligation product, primarily due to the complex procedure of the EPL, preventing EPL from gaining popularity in the research community. Here we report an efficient on-column EPL strategy, which focuses on enhancing the expression level of the intein-fusion protein that generates thioester fo...

  20. Nitrogen Isotopes - Tracers for Nitrogen Transformations in Small Constructed Wetlands

    Science.gov (United States)

    Reinhardt, M.; Gaechter, R.; Mueller, B.; Wehrli, B.

    2005-05-01

    Small artificial wetlands are increasingly applied to reduce non-point source pollution and to contribute to the restoration of eutrophicated freshwaters and coastal marine ecosystems. In the agricultural catchment area of Lake Sempach in Central Switzerland, several wetlands were constructed at the interface between subsurface drainage system and receiving waters. In order to evaluate nitrogen retention efficiency of the systems and to identify major processes controlling their performance, nitrate, ammonium, particulate and dissolved organic nitrogen in the inflowing and outflowing water as well as δ15N of nitrate, ammonium and sediment were analyzed in a three pond system. During the studied 26 months the wetland retained 27% of the nitrogen load corresponding to a surface related retention of 51g N m-2 yr-1. Nitrate in the inlet contributed 48% to the total nitrogen load and was characterized by high δ15N-NO3(>13‰) typical for intensively manured grassland soils. Increasing δ15N-NO3 in the wetland compared to the inlet was attributed to denitrification whereas decreasing δ15N-NO3 during stagnant periods was due to anoxic mineralization of particulate organic matter and subsequent nitrification.

  1. Cascading costs: An economic nitrogen cycle

    Institute of Scientific and Technical Information of China (English)

    William; R.; Moomaw; Melissa; B.; L.; Birch

    2005-01-01

    The chemical nitrogen cycle is becoming better characterized in terms of fluxes and reservoirs on a variety of scales. Galloway has demonstrated that reactive nitrogen can cascade through multiple ecosystems causing environmental damage at each stage before being denitrifled to N2. We propose to construct a parallel economic nitrogen cascade (ENC) in which economic impacts of nitrogen fluxes can be estimated by the costs associated with each stage of the chemical cascade. Using economic data for the benefits of damage avoided and costs of mitigation in the Chesapeake Bay basin, we have constructed an economic nitrogen cascade for the region. Since a single tonne of nitrogen can cascade through the system, the costs also cascade.Therefore evaluating the benefits of mitigating a tonne of reactive nitrogen released needs to consider the damage avoided in all of the ecosystems through which that tonne would cascade.The analysis reveals that it is most cost effective to remove a tonne of nitrogen coming from combustion since it has the greatest impact on human health and creates cascading damage through the atmospheric, terrestrial, aquatic and coastal ecosystems. We will discuss the implications of this analysis for determining the most cost effective policy option for achieving environmental quality goals.

  2. Synthesis and Characterization of 5-Nitro-2-nitratomethyl-1,2,3,4-tetrazole: A High Nitrogen Energetic Compound with Good Oxygen Balance

    Directory of Open Access Journals (Sweden)

    Siping Pang

    2012-05-01

    Full Text Available The synthesis of 5-nitro-2-nitratomethyl-1,2,3,4-tetrazole (4 and its full characterization are given here. Compound 4 was synthesized through the nitration of 5-nitro-2-hydroxymethyl-tetrazole (3 with fuming nitric acid and acetic anhydride and its structure was characterized by MS, FT-IR, 1H-NMR and 13C-NMR techniques. The crystal structure of 4 was determined by X-ray single crystal diffraction analysis. The compound belongs to the orthorhombic system with space group Pna2(1, and its crystal parameters were a = 2.121(8 nm, b = 0.5281(19 nm, c = 0.6246(2 nm, Z = 4, V = 0.6995(4 nm3, Dc = 1.805 g/cm3, F(000 = 384, μ = 0.174 mm−1. A theoretical study of 4 has been performed, using quantum computational density functional theory (B3LYP methods with 6-31G* basis sets as implemented in the Gaussian 03 program suite. The obtained heat of formation (HOF for 4 was 228.07 kJ·mol−1, the detonation pressure (P values calculated for 4 was 37.92 GPa, the detonation velocity (D can reach 9260 m·s−1, and the oxygen balance was zero (Q, making 4 a competitive energetic compound.

  3. Characterization of the source distribution of particulate matter and nitrogen oxides in rural and urban areas; Charakterisierung der Quellverteilung von Feinstaub und Stickoxiden in laendlichem und staedtischem Gebiet

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Susanna

    2010-07-01

    . It could be demonstrated that the total background is composed of quantifying fractions of the regional and the urban background. The difference of the current measuring signals and the regional background represents the maximum achievable release potential through traffic related activities for traffic dominated trace substances. Moreover, typical particulate size distributions and VOC-compositions of different contamination scenarios (urban, suburban and rural with biogenic contribution) could be determined. Adequate weather conditions approved the investigation of inversion layers of trace substances by the passing of a mountain when using the ''driving air-lab''. During the measurement campaign in Duesseldorf three characteristic measuring scenarios of a city, arterial streets, side streets and a tunnel, were distinguished. The correlation analysis showed a coemission of particles and nitrogen oxides. Furthermore, a total background concentration-field with street resolution of a residential area was created which reveals that the representativeness of a hypothetical measuring station only reaches a few 100 m. The multiregression analysis with source pattern of different engine systems in variable operating conditions demonstrated that the main contribution of the VOC-emissions derives from gasoline engines in cold start status. To determine the reaching range of an intense line source, measurements on and close to the highway in the area of Juelich were performed. By means of the crossing of a highway bridge the particle size concentrations demonstrate that the sphere of influence of a highway reaches several 100 m depending on the meteorological and orographic conditions. The gas chromatographic analysis and the following pattern analysis of mobile collected filters of a measuring route in the area of Juelich with motorway, highway, urban and rural road parts revealed a diesel soot contribution of more than 40% to total particulate matter

  4. N掺杂富含(001)晶面TiO2纳米片的制备及N掺杂浓度对可见光催化活性的影响%Synthesis, Characterization, and Nitrogen Concentration Depended Visible-Light Photoactivity of Nitrogen-Doped TiO2 Nanosheets with Dominant (001) Facets

    Institute of Scientific and Technical Information of China (English)

    王卫; 陆春华; 苏明星; 倪亚茹; 许仲梓

    2012-01-01

    采用水热法制备了富含(001)晶面的锐钛矿型TiO2纳米片,并通过改变热处理过程中NH3流速制备不同N掺杂浓度的TiO2纳米片.运用X射线衍射、场发射扫描电镜、高分辨率透射电子显微镜、紫外-可见漫反射光谱、X射线光电子能谱和荧光光谱对光催化剂进行了结构和性能表征,并以罗丹明B为目标降解物,考察了N掺杂浓度对TiO2纳米片可见光催化活性的影响.结果表明,NH3流速为40 ml/min时制备的N掺杂TiO2纳米片具有最低的光生电子-空穴复合速率,最高的·OH产生能力并表现出最高的光催化活性.同时,讨论了N掺杂浓度对TiO2纳米片可见光催化活性影响的机理.%Anatase TiO2 nanosheets with dominant (001) facets were prepared by a simple hydrothermal method.Nitrogen-doped TiO2 nanosheets (TiO2-N) with different nitrogen concentration were successfully synthesized by annealing TiO2 nanosheets in NH3 atmosphere with different NH3 flow rate at 400 ℃ for 3 h.The morphology,nanostructures,and properties of TiO2-N were characterized by X-ray diffraction,field emission scanning electron microscopy,high resolution transmission electron microscopy,ultraviolet-visible diffuse reflection spectroscopy,X-ray photoelectron spectroscopy,and photoluminescence.The effects of NH3 flow rate on the nanostructures,properties,and visible-light photoactivity in the degradation of rhodamine B (RhB) aqueous solution under visible light (λ > 400 nm) irradiation of the prepared photocatalysts were investigated.Among all the prepared photocatalysts including nitrogen modified P25 (Degussa),TiO2-N prepared with a NH3 flow rate of 40 ml/min gave the highest visible-light photoactivity because of the dominant (001) facets,visible light responsibility,the slowest photogenerated electron (e-) and hole (h+) pairs recombination rate,and the highest hydroxyl radicle (·OH) generation ability.Based on these experiments and analysis,the mechanisms of how

  5. Zeolite ZSM5 catalysts for abatement of nitrogen oxide

    Energy Technology Data Exchange (ETDEWEB)

    Ganemi, Bager

    1999-07-01

    Airborne pollutants from the combustion of fossil fuels are a global problem. Emission of nitrogen oxides (NO{sub x}) is increasing with the worldwide increase in the use of energy. Atmospheric and photochemical reactions link nitrogen oxides to hydrocarbons and tropospheric ozone. The emission of NO{sub x} has to be tackled urgently in order to limit the harmful effects of anthropogenic activity on the environment. The subject of this thesis is catalytic nitrogen oxide abatement through direct decomposition and reduction by methane over ion-exchanged zeolite ZSM5. The work covers catalytic conversion and surface intermediates, including correlations with the level of exchanged Cu{sup 2+} cations and Ni{sup 2+} or Pd{sup 2+} co-cations. Special attention is given to the aluminium content of the support and changes in structural parameters. It was found that NO{sub x} conversion over cation-exchanged ZSM5 is strongly influenced by the ion-exchange procedure and by the above material parameters. Characterization of Cu-ZSM5 reveals that approximately two molecules of water per Cu{sup 2+} ion desorb at temperatures between 150 and 350 Deg C, in addition to the conventional dehydration at lower temperatures. The desorbed water comes from the decomposition of Cu(OH){sub 2}. Decomposition of hydroxylated copper ions results in the formation Of Cu{sup 2+}-O-Cu{sup 2+} dimers, which are suggested to be the active sites for catalytic decomposition of NO. Acid sites are important for the dispersion of copper ions on the catalyst surface. Acid sites are also important for the interaction between copper species and the zeolite. Increased acidity leads to a stronger interaction between the exchanged cation and the framework, i.e. the exchanged cations become more resistant to mobility. The stronger bond between the exchanged cations and lattice oxygen also prevents dealumination of the catalyst and decreases the thermal expansion at higher temperatures. The temperature of

  6. Sequential ultrasonic extraction of a Chinese coal and characterization of nitrogen-containing compounds in the extracts using high-performance liquid chromatography with mass spectrometry.

    Science.gov (United States)

    Xia, Jun-Liu; Fan, Xing; You, Chun-Yan; Wei, Xian-Yong; Zhao, Yun-Peng; Cao, Jing-Pei

    2016-07-01

    Dongming lignite was sequentially extracted with petroleum ether, carbon disulfide, methanol, acetone, and isometric carbon disulfide/acetone mixed solvent at room temperature to afford extracts 1-5, respectively. High-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry was used to separate and characterize heteroatomic species in the extracts at molecular level. Molecular mass of compounds in the extracts is mainly distributed from 300 to 800 u, and the relative abundance of compounds with molecular mass over 800 u in the carbon disulfide extract is 135 times of that in the petroleum ether extract. The acetone extract has the highest relative abundance for organonitrogen compounds. Double bond equivalence numbers of detected species indicate that most of the organonitrogen compounds contain N-heterocyclic aromatic rings, including pyridine, quinoline and pyrrole. Some organonitrogen isomers in Dongming lignite were separated and identified by high-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry, and the corresponding structural information was proposed.

  7. Characterization of the source distribution of particulate matter and nitrogen oxides in rural and urban areas; Charakterisierung der Quellverteilung von Feinstaub und Stickoxiden in laendlichem und staedtischem Gebiet

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Susanna

    2010-07-01

    . It could be demonstrated that the total background is composed of quantifying fractions of the regional and the urban background. The difference of the current measuring signals and the regional background represents the maximum achievable release potential through traffic related activities for traffic dominated trace substances. Moreover, typical particulate size distributions and VOC-compositions of different contamination scenarios (urban, suburban and rural with biogenic contribution) could be determined. Adequate weather conditions approved the investigation of inversion layers of trace substances by the passing of a mountain when using the ''driving air-lab''. During the measurement campaign in Duesseldorf three characteristic measuring scenarios of a city, arterial streets, side streets and a tunnel, were distinguished. The correlation analysis showed a coemission of particles and nitrogen oxides. Furthermore, a total background concentration-field with street resolution of a residential area was created which reveals that the representativeness of a hypothetical measuring station only reaches a few 100 m. The multiregression analysis with source pattern of different engine systems in variable operating conditions demonstrated that the main contribution of the VOC-emissions derives from gasoline engines in cold start status. To determine the reaching range of an intense line source, measurements on and close to the highway in the area of Juelich were performed. By means of the crossing of a highway bridge the particle size concentrations demonstrate that the sphere of influence of a highway reaches several 100 m depending on the meteorological and orographic conditions. The gas chromatographic analysis and the following pattern analysis of mobile collected filters of a measuring route in the area of Juelich with motorway, highway, urban and rural road parts revealed a diesel soot contribution of more than 40% to total particulate matter

  8. Coenzyme B12 model studies: An HSAB approach to the equilibria and kinetics of axial ligation of alkyl(aquo)-cobaloximes by imidazole and cyanide

    Indian Academy of Sciences (India)

    Vaddeboina Sridhar; S Satyanarayana

    2000-12-01

    Kinetics and equilibria of the axial ligation of alkyl(aquo)cobaloximes by imidazole and cyanide have been measured spectrophotometrically in aqueous solutions of ionic strength 1.0 M at 25°C as a function of H. Comparison of IMD and CN- of CH3, C2H5 and BrCH2 cobaloximes indicates that their stability is in the order BrCH2 > CH3 > C2H5. As the electron-withdrawing capacity of the alkyl group trans to water increases, the electron density of the cobalt(III) decreases and thus it becomes a stronger Lewis acid and binds more strongly to imidazole and cyanide. The association and dissociation rate constants are better correlated to the relative softness of the ligand showing that cyanide binds 30 times faster than imidazole. These complexes are isolated and are characterized by IR and 1H NMR spectra.

  9. Coenzyme B12 model studies: Equilibrium constants for the H-dependent axial ligation of benzyl(aquo)cobaloxime by various N- and S-donor ligands

    Indian Academy of Sciences (India)

    D Sudarshan Reddy; N Ravi Kumar Reddy; V Sridhar; S Satyanarayana

    2002-02-01

    Equilibria of the axial ligation of benzyl(aquo)cobaloximes by imidazole, 1-methyl imidazole, histidine, histamine, glycine, ethyl glycine ester, thiourea and urea have been spectrophotometrically measured in aqueous solutions of ionic strength 1.0 M (KCl) at 25°C as a function of H. The equilibrium constants are in the order CN- > 1-methyl imidazole > imidazole > histidine > histamine > glycine > ethyl glycine ester > thiourea > urea. The order of stability of benzyl(ligand)cobaloxime is explained based on the basicity of the ligand, Co(III) → - back bonding and soft-soft and soft-hard interaction. Imidazole, substituted imidazoles, histidine and histamine form more stable complexes than glycine, ethyl glycine ester in contrast to the basicity of the ligands. Benzyl(ligand)cobaloximes were isolated and characterized by elemental analysis, IR and 1H NMR spectra.

  10. Genome-wide investigation and functional characterization of the β-ketoadipate pathway in the nitrogen-fixing and root-associated bacterium Pseudomonas stutzeri A1501

    Directory of Open Access Journals (Sweden)

    Geng Lizhao

    2010-02-01

    Full Text Available Abstract Background Soil microorganisms are mainly responsible for the complete mineralization of aromatic compounds that usually originate from plant products or environmental pollutants. In many cases, structurally diverse aromatic compounds can be converted to a small number of structurally simpler intermediates, which are metabolized to tricarboxylic acid intermediates via the β-ketoadipate pathway. This strategy provides great metabolic flexibility and contributes to increased adaptation of bacteria to their environment. However, little is known about the evolution and regulation of the β-ketoadipate pathway in root-associated diazotrophs. Results In this report, we performed a genome-wide analysis of the benzoate and 4-hydroxybenzoate catabolic pathways of Pseudomonas stutzeri A1501, with a focus on the functional characterization of the β-ketoadipate pathway. The P. stutzeri A1501 genome contains sets of catabolic genes involved in the peripheral pathways for catabolism of benzoate (ben and 4-hydroxybenzoate (pob, and in the catechol (cat and protocatechuate (pca branches of the β-ketoadipate pathway. A particular feature of the catabolic gene organization in A1501 is the absence of the catR and pcaK genes encoding a LysR family regulator and 4-hydroxybenzoate permease, respectively. Furthermore, the BenR protein functions as a transcriptional activator of the ben operon, while transcription from the catBC promoter can be activated in response to benzoate. Benzoate degradation is subject to carbon catabolite repression induced by glucose and acetate in A1501. The HPLC analysis of intracellular metabolites indicated that low concentrations of 4-hydroxybenzoate significantly enhance the ability of A1501 to degrade benzoate. Conclusions The expression of genes encoding proteins involved in the β-ketoadipate pathway is tightly modulated by both pathway-specific and catabolite repression controls in A1501. This strain provides an ideal

  11. Assessment of MRI issues at 3-Tesla for metallic surgical implants: findings applied to 61 additional skin closure staples and vessel ligation clips

    Directory of Open Access Journals (Sweden)

    Gill Amreeta

    2012-01-01

    Full Text Available Abstract Purpose Metallic skin closure staples and vessel ligation clips should be tested at 3-Tesla to characterize MRI issues in order to ensure patient safety. Therefore, metallic surgical implants were assessed at 3-Tesla for magnetic field interactions, MRI-related heating, and artifacts. Methods A skin closure staple (Visistat Skin Stapler, staple, Polytetrafluoroethylene, PTFE, coated 316L/316LVM stainless steel; Teleflex Medical, Durham, NC and a vessel ligation clip (Hemoclip Traditional, stainless steel; Teleflex Medical, Durham, NC that represented the largest metallic sizes made from materials with the highest magnetic susceptibilities (i.e., based on material information among 61 other surgical implants (52 metallic implants, 9 nonmetallic implants underwent evaluation for magnetic field interactions, MRI-related heating, and artifacts using standardized techniques. MRI-related heating was assessed by placing each implant in a gelled-saline-filled phantom with MRI performed using a transmit/receive RF body coil at an MR system reported, whole body averaged SAR of 2.9-W/kg for 15-min. Artifacts were characterized using T1-weighted, SE and GRE pulse sequences. Results Each surgical implant showed minor magnetic field interactions (20- and 27-degrees, which is acceptable from a safety consideration. Heating was not substantial (highest temperature change, ≤ 1.6°C. Artifacts may create issues if the area of interest is in the same area or close to the respective surgical implant. Conclusions The results demonstrated that it would be acceptable for patients with these metallic surgical implants to undergo MRI at 3-Tesla or less. Because of the materials and dimensions of the surgical implants that underwent testing, these findings pertain to 61 additional similar implants.

  12. Increased Expression of TGF-β Signaling Components in a Mouse Model of Fibrosis Induced by Submandibular Gland Duct Ligation.

    Directory of Open Access Journals (Sweden)

    Lucas T Woods

    Full Text Available Transforming growth factor-β (TGF-β is a multi-functional cytokine with a well-described role in the regulation of tissue fibrosis and regeneration in the liver, kidney and lung. Submandibular gland (SMG duct ligation and subsequent deligation in rodents is a classical model for studying salivary gland damage and regeneration. While previous studies suggest that TGF-β may contribute to salivary gland fibrosis, the expression of TGF-β signaling components has not been investigated in relation to mouse SMG duct ligation-induced fibrosis and regeneration following ductal deligation. Following a 7 day SMG duct ligation, TGF-β1 and TGF-β3 were significantly upregulated in the SMG, as were TGF-β receptor 1 and downstream Smad family transcription factors in salivary acinar cells, but not in ductal cells. In acinar cells, duct ligation also led to upregulation of snail, a Smad-activated E-cadherin repressor and regulator of epithelial-mesenchymal transition, whereas in ductal cells upregulation of E-cadherin was observed while snail expression was unchanged. Upregulation of these TGF-β signaling components correlated with upregulation of fibrosis markers collagen 1 and fibronectin, responses that were inhibited by administration of the TGF-β receptor 1 inhibitors SB431542 or GW788388. After SMG regeneration following a 28 day duct deligation, TGF-β signaling components and epithelial-mesenchymal transition markers returned to levels similar to non-ligated controls. The results from this study indicate that increased TGF-β signaling contributes to duct ligation-induced changes in salivary epithelium that correlate with glandular fibrosis. Furthermore, the reversibility of enhanced TGF-β signaling in acinar cells of duct-ligated mouse SMG after deligation indicates that this is an ideal model for studying TGF-β signaling mechanisms in salivary epithelium as well as mechanisms of fibrosis initiation and their resolution.

  13. Nitrogen control of chloroplast differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, G.W.

    1992-07-01

    This project is directed toward understanding how the availability of nitrogen affects the accumulation of chloroplast pigments and proteins functioning in energy transduction and carbon metabolism. Molecular analyses performed with Chlamydomonas reinhardtii grown in a continuous culture system such that ammonium concentration is maintained at a low steady-state concentration so as to limit cell division. As compared to chloroplasts from cells of non-limiting nitrogen provisions, chloroplasts of N-limited cells are profoundly chlorophyll-deficient but still assimilate carbon for deposition of as starch and as storage lipids. Chlorophyll deficiency arises by limiting accumulation of appropriate nuclear-encoded mRNAs of and by depressed rates of translation of chloroplast mRNAs for apoproteins of reaction centers. Chloroplast translational effects can be partially ascribed to diminished rates of chlorophyll biosynthesis in N-limited cells, but pigment levels are not determinants for expression of the nuclear light-harvesting protein genes. Consequently, other signals that are responsive to nitrogen availability mediate transcriptional or post-transcriptional processes for accumulation of the mRNAs for LHC apoproteins and other mRNAs whose abundance is dependent upon high nitrogen levels. Conversely, limited nitrogen availability promotes accumulation of other proteins involved in carbon metabolism and oxidative electron transport in chloroplasts. Hence, thylakoids of N-limited cells exhibit enhanced chlororespiratory activities wherein oxygen serves as the electron acceptor in a pathway that involves plastoquinone and other electron carrier proteins that remain to be thoroughly characterized. Ongoing and future studies are also outlined.

  14. A comparison of the forces required to produce tooth movement in vitro using two self-ligating brackets and a pre-adjusted bracket employing two types of ligation.

    Science.gov (United States)

    Sims, A P; Waters, N E; Birnie, D J; Pethybridge, R J

    1993-10-01

    Friction in fixed appliance systems has received considerable attention in the recent literature, although that attributable to the type of ligation used has not been fully investigated. This in vitro study of 0.022 x 0.028 inch slot Minitwin, Activa ('A' Company, San Diego, California, USA), and SPEED brackets (Strite Industries Ltd., Cambridge, Ontario, Canada), investigates friction in two forms of self-ligating brackets and in two methods of ligating Minitwin straight wire brackets with polyurethane elastomeric ligatures. The resistance to sliding of rectangular archwires through the ligated brackets was measured on a vertically mounted Instron testing machine. The stainless steel archwires used were straight lengths of 0.016" x 0.022", 0.017" x 0.025", 0.018" x 0.025", and 0.019" x 0.025" Nubryte Gold (GAC International Inc., Central Islip, New York, USA). The results showed a significant reduction (P brackets compared with SPEED brackets by a factor of approximately 15. When the SPEED brackets were compared to Minitwin brackets, the reduction in friction was by 50-70 per cent (P self-ligating brackets require less force to produce tooth movement because they apply less frictional contact to the archwire than conventionally tied siamese brackets. PMID:8223972

  15. Comparative assessment of forces generated during simulated alignment with self-ligating and conventional brackets.

    Science.gov (United States)

    Pandis, Nikolaos; Eliades, Theodore; Bourauel, Christoph

    2009-12-01

    The objectives of this study were to comparatively assess the magnitude and direction of forces and moments generated from different bracket systems, during the initial levelling and alignment stage of orthodontic treatment. Three types of brackets were used: Orthos2 (Ormco), Damon2 (Ormco), and In-Ovation R (GAC). The brackets were bonded on resin replicas models of a patient's crowded mandibular arch, and a 0.014 inch Damon archform CuNiTi (Ormco) wire was inserted. The model was mounted on the Orthodontic Measurement and Simulation System (OMSS) and six static measurements were taken at the initial crowded state per bracket for the lateral incisor, canine, and first premolar. A total of 10 repetitions were performed for each measurement, with new brackets and archwires used for each trial. The forces and moments generated were registered directly on the OMSS software and were statistically analyzed using a one-way analysis of variance separately for each dental arch location and force component. Group differences were further analyzed with Tukey's post hoc comparisons test at the 0.05 significance level. The lingually inclined, crowded lateral incisor presented an extrusive and buccal movement and showed the lowest force in the vertical direction, whereas the self-ligating group of brackets generated the highest force in the buccolingual direction. The moments applied by the three bracket systems followed the general trend shown for forces; in the vertical axis, the self-ligating brackets exerted lower forces than their conventional counterpart. This was modified in the buccolingual direction where, in most instances, the self-ligating appliances applied higher moments compared with the conventional bracket. In most cases, the magnitude of forces and moments ranged between 30-70 cN and 2-6 N mm, respectively. However, maximum forces and moments developed at the lateral incisor were almost four times higher than the average. PMID:19349418

  16. The preparation of aneurysm model in rabbits by vessel ligation and elastase-induced technique

    International Nuclear Information System (INIS)

    Objective: To establish an aneurysm model, which is quite similar to the human intracranial aneurysm in morphology, in rabbits by means of vessel ligation together with elastase-induced technique. Methods: Sixteen New Zealand white rabbits were used in this study. Distal carotid ligation and intraluminal elastase incubation was employed in ten rabbits (study group) to create aneurysm on the right common carotid artery. And surgical suture of a segment of the left carotid common artery was carried out in six rabbits (used as control group) to establish the aneurysm model. DSA exam of the created aneurysms by using catheterization via femoral artery was performed at one week and at one month after surgery. The patency, morphology and pathology of the aneurysms were observed. The results were statistically analyzed. Results: The aneurysms in both groups remained patent after they were created. Angiography one week after the surgery showed that all the aneurysms in study group were patent, while in control group only two aneurysms showed opacification with contrast medium and the remaining four aneurysms were all occluded. DSA at one month after the procedure demonstrated that all the aneurysms in study group remained patent, and the previous two patent aneurysms in control group became occluded. The mean width and length of the aneurysmal cavity in study group immediately after the procedure were (3.70 ± 0.16) mm and (6.53 ± 0.65) mm respectively, which enlarged to (5.06 ± 0.31) mm and (9.0 ± 0.52) mm respectively one month after the surgery. The difference in size changes was statistically significant (P < 0.05). Pathologically, almost complete absence of the internal elastic lamina and medial wall elastin of the aneurysms was observed. Conclusion: The aneurysm model prepared with vessel ligation together with elastase-induced technique carries high patent rate and possesses the feature of spontaneous growing, moreover, its morphology is quite similar to the

  17. Evaluation of seamless ligation cloning extract preparation methods from an Escherichia coli laboratory strain.

    Science.gov (United States)

    Okegawa, Yuki; Motohashi, Ken

    2015-10-01

    Seamless ligation cloning extract (SLiCE) is a simple and efficient method for DNA cloning without the use of restriction enzymes. Instead, SLiCE uses homologous recombination activities from Escherichia coli cell lysates. To date, SLiCE preparation has been performed using an expensive commercially available lytic reagent. To expand the utility of the SLiCE method, we evaluated different methods for SLiCE preparation that avoid using this reagent. Consequently, cell extracts prepared with buffers containing Triton X-100, which is a common and low-cost nonionic detergent, exhibited sufficient cloning activity for seamless gene incorporation into a vector. PMID:26133399

  18. Is it safe to divide and ligate the left innominate vein in complex cardiothoracic surgeries?

    Science.gov (United States)

    McPhee, Arthur; Shaikhrezai, Kasra; Berg, Geoffrey

    2013-09-01

    A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether it is safe to divide the left innominate vein (LIV) in aortic arch surgery to improve access. Altogether, 228 relevant papers were found using the reported search, of which nine represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Following LIV division, the venous drainage takes place via multiple collateral systems such as the azygous/hemiazygous, the internal mammary veins, the lateral thoracic and superficial thoracoabdominal veins, vertebral venous plexus as well as the transverse sinus. The possible complications are mainly left upper limb swelling and neurological symptoms. In one case series of 14 patients, the LIV was divided and ligated to facilitate the exposure for aortic arch surgery. More than 2-year follow-up did not reveal upper limb oedema or neurological symptoms. In two cohorts of 52 patients, the LIV was ligated prior to the superior vena cava (SVC) resection for malignancy. During the mid-term follow-up, no neurological or upper limb symptoms were reported. Although in two studies with 72 and 70 patients undergoing SVC resection it was not specified how many of them had LIV ligation, no relevant complications were reported. In a report, LIV occlusion was observed in 4 patients undergoing left internal jagular vein catheterization for haemodialysis. The reported symptom was left arm swelling with no neurological problems. In a cohort of 18 patients undergoing SVC resection for malignancy and major vein reconstruction, 7 patients underwent ligation of the LIV with no neurological symptoms. It was also concluded that reconstruction of the LIV is not consistent with favourable patency. In a case series of 10 patients with central venous obstruction, collateral pathways

  19. Evaluation of seamless ligation cloning extract preparation methods from an Escherichia coli laboratory strain.

    Science.gov (United States)

    Okegawa, Yuki; Motohashi, Ken

    2015-10-01

    Seamless ligation cloning extract (SLiCE) is a simple and efficient method for DNA cloning without the use of restriction enzymes. Instead, SLiCE uses homologous recombination activities from Escherichia coli cell lysates. To date, SLiCE preparation has been performed using an expensive commercially available lytic reagent. To expand the utility of the SLiCE method, we evaluated different methods for SLiCE preparation that avoid using this reagent. Consequently, cell extracts prepared with buffers containing Triton X-100, which is a common and low-cost nonionic detergent, exhibited sufficient cloning activity for seamless gene incorporation into a vector.

  20. The effect of ligation of the distal vein in snuff-box arteriovenous fistula

    OpenAIRE

    Beigi Ali; Masoudpour Hassan; Alavi Maryam

    2009-01-01

    Arterio-venous fistula (AVF) in the snuff-box region is one of the current techniques used for creating a vascular access in patients undergoing dialysis. The aim of this study is to find out whether ligating the distal vein in AVF in the snuff-box will bring about any change in the efficiency and complications of the fistula. Sixty patients (30 males, 30 females) suffering from chronic renal failure, who had been admitted for creating an AVF, were randomly divided into two groups after havin...

  1. A new resorbable device for ligation of blood vessels - A pilot study

    Directory of Open Access Journals (Sweden)

    Borg Niklas

    2011-07-01

    Full Text Available Abstract Background During surgery, controlled haemostasis to prevent blood loss is vital for a successful outcome. It can be difficult to ligate vessels located deep in the abdomen. A device that is easy to use and enables secure ligatures could be beneficial. Cable ties made of nylon have been used for ligation but the non-resorbable material caused tissue reactions. The objective of this study was to use a resorbable material to construct a device with a self-locking mechanism and to test its mechanical strength and ligation efficiency. Methods The device was manufactured by injection moulding of polydioxanone, a resorbable polymer used for suture materials. Polydioxanone with inherent viscosities of 1.9 dL/g and 1.3 dL/g were tested. The device consisted of a perforated flexible band which could be pulled through a case with a locking mechanism. After a first version of the device had been tested, some improvements were made. The locking case was downsized, corners were rounded off, the band was made thicker and the mould was redesigned to produce longer devices. Tensile tests were performed with the second version. The first version of the device was used to ligate the ovarian pedicle in a euthanized dog and to test echogenicity of the device with ultrasound. Compression of vessels of the ovarian pedicle was examined by histology. Both versions of the device were tested for haemostasis of and tissue grip on renal arteries in six anaesthetised pigs. Results The tensile strength of the flexible band of the devices with inherent viscosity of 1.9 dL/g was 50.1 ± 5.5 N (range 35.2-62.9 N, n = 11 and the devices with inherent viscosity of 1.3 dL/g had a tensile strength of 39.8 ± 8.1 N (range 18.6-54.2 N, n = 11. Injection moulding of the polymer with lower inherent viscosity resulted in a longer flow distance. Both versions of the device had an effective tissue grip and complete haemostasis of renal arteries was verified. The device attached

  2. Molecular Recognition of Cobalt(III)-ligated Peptides by Serine Proteases: The Role of Electrostatic Effects

    DEFF Research Database (Denmark)

    Bagger, Sven; Wagner, Kim

    1998-01-01

    A series of peptides with a positively charged cobalt(III)-complex group attached to the carboxylate terminal was synthesized. The behaviour of these metallopeptides as acceptor nucleophiles in acyl transfer reactions catalyzed by the three serine proteases bovine pancreatic à-chymotrypsin, porcine...... pancreatic trypsin, and proteinase K from Tritirachium album was examined. The efficiency of the substrates was assessed by kinetic measurement of the partition between aminolysis and hydrolysis. The results are discussed with special reference to coulombic interactions between the metal-ligated substrates...... and charged residues on the enzyme surfaces. The idea of using the metallopeptides in practical enzymatic peptide synthesis is put forward....

  3. Multiplexed homogeneous proximity ligation assays for high throughput protein biomarker research in serological material

    DEFF Research Database (Denmark)

    Lundberg, Martin; Thorsen, Stine Buch; Assarsson, Erika;

    2011-01-01

    A high throughput protein biomarker discovery tool has been developed based on multiplexed proximity ligation assays (PLA) in a homogeneous format in the sense of no washing steps. The platform consists of four 24-plex panels profiling 74 putative biomarkers with sub pM sensitivity each consuming...... only 1 micro Litre of human plasma sample. The system uses either matched monoclonal antibody pairs or the more readily available single batches of affinity purified polyclonal antibodies to generate the target specific reagents by covalently linking with unique nucleic acid sequences. These paired...

  4. DiGeorge Critical Region 8 (DGCR8) Is a Double-cysteine-ligated Heme Protein*

    OpenAIRE

    Barr, Ian; Smith, Aaron T.; Senturia, Rachel; Chen, Yanqiu; Scheidemantle, Brooke D.; Burstyn, Judith N.; Guo, Feng

    2011-01-01

    All known heme-thiolate proteins ligate the heme iron using one cysteine side chain. We previously found that DiGeorge Critical Region 8 (DGCR8), an essential microRNA processing factor, associates with heme of unknown redox state when overexpressed in Escherichia coli. On the basis of the similarity of the 450-nm Soret absorption peak of the DGCR8-heme complex to that of cytochrome P450 containing ferrous heme with CO bound, we identified cysteine 352 as a probable axial ligand in DGCR8. Her...

  5. Gastroprotective Effect of Rubia cordifolia Linn. on Aspirin Plus Pylorus-Ligated Ulcer

    Directory of Open Access Journals (Sweden)

    R. S. Deoda

    2011-01-01

    Full Text Available The present study was designed to investigate the effect of Rubia cordifolia (Rubiaceae against experimentally induced gastric ulcer and compare activity with its fractions by employing aspirin plus pylorus-ligated ulcer screening model in Wistar rats. Total acidity, volume of gastric acid secretion, total acid output, and pepsin activity show significant reduction, when compared with the control group. The present study confirmed that chloroform fraction showed the significant activity at lower doses compared to parent extract. The mechanism can be attributed to decrease in gastric acid secretary activity along with strengthening of mucosal defensive mechanism by prostaglandin synthesis and antioxidant potential.

  6. Identification of Cystic Fibrosis Variants by Polymerase Chain Reaction/Oligonucleotide Ligation Assay

    OpenAIRE

    Schwartz, Karen M.; Pike-Buchanan, Lisa L.; Muralidharan, Kasinathan; Redman, Joy B.; Wilson, Jean Amos; Jarvis, Michael; Cura, M. Grace; Pratt, Victoria M.

    2009-01-01

    The purpose of this work is to define rare variants of cystic fibrosis (CF) that are potential sources of error and can confound molecular genetic testing methods. We performed routine, clinical CF mutation screening using a laboratory-developed test and the oligonucleotide ligation assay reagents from Abbott/Celera. In this report, we describe 11 unique allele drop outs [3849 + 10kb C>T (NM_000492.2:c.3718-2477C>T), V520F (c.1558G>T), 1078delT (c.948delT), A455E (c.1364C>A), R347P (c.1040G>C...

  7. Coated Rectangular Composite Archwires: A Comparison Of Self-Ligating And Conventional Bracket Systems During Sliding Mechanics

    Science.gov (United States)

    Woods, David Keith

    The purpose of this study was to analyze the resistance to sliding of coated rectangular fiber reinforced composite archwires using various brackets systems and second-order bracket angulations. Resistance to sliding was investigated for eight bracket systems: six self-ligating brackets (four passive and two passive-active) and two conventional brackets. A rectangular fiber reinforced composite archwire of 0.019 x 0.025-in dimension from BiomersRTM SimpliClear was drawn through a three-bracket model system at ten millimeters per minute for 2.5 millimeters. For each bracket, the resistance to sliding was measured at four bracket angulations (0°, 2.5°, 5°, and 10°) in a dry state at room temperature. The fiber reinforced composite archwire produced the lowest sliding resistance with the passive self-ligating bracket system (Damon DQ) at each bracket angulation tested. Overall, self-ligating bracket systems generated lower sliding resistance than conventionally ligated systems, and one passive/active self-ligating bracket system (In-Ovation-R). There was a significant increase in resistance to sliding as bracket angulation increased for all bracket systems tested. Microscopic analysis revealed increased perforation of the archwire coating material as bracket angulations were increased. Our findings show that the rectangular fiber reinforced composite archwire may be acceptable for sliding mechanics during the intermediate stages of orthodontic tooth movement, however more long-term studies are needed.

  8. Alterations in plaque accumulation and gingival inflammation promoted by treatment with self-ligating and conventional orthodontic brackets

    Science.gov (United States)

    Cardoso, Mauricio de Almeida; Saraiva, Patrícia Pinto; Maltagliati, Liliana Ávila; Rhoden, Fernando Kleinübing; Costa, Carla Cristina Alvarenga; Normando, David; Capelozza, Leopoldino

    2015-01-01

    OBJECTIVE: The aim of the present study was to evaluate, comparatively, the periodontal response during orthodontic treatment performed with self-ligating and conventional brackets. METHODS: Sixteen Caucasian individuals of both sexes, aged between 12 and 16 years old and in permanent dentition were selected. Eight individuals were treated with conventional brackets installed on the lower dental arch and self-ligating brackets on the upper arch. Another eight individuals received self-ligating brackets in the lower arch and conventional brackets in the upper arch. The subjects received material and instructions for oral hygiene. Visible plaque index (VPI), gingival bleeding index (GBI) and clinical attachment level (CAL) were evaluated just after installation of orthodontic appliances, and 30, 60 and 180 days later. Mann-Whitney test was used to compare differences between groups (self-ligating and conventional), two-way ANOVA followed by Tukey's test was used to assess CAL at each site of each tooth. Significance level was set at 5%. RESULTS: No significant changes were found with regard to the assessed parameters (VPI, GBI and CAL) in either one of the systems. CONCLUSION: No significant changes were found with regard to the periodontal response to orthodontic treatment for the variables assessed and between subjects receiving passive self-ligating and conventional brackets. All individuals had received oral hygiene instructions and had their periodontal conditions monitored. PMID:25992985

  9. A pilot randomized control study to evaluate endoscopic resection using a ligation device for rectal carcinoid tumors

    Institute of Scientific and Technical Information of China (English)

    Hiroyuki Sakata; Sadahiro Amemori; Kotaro Mannen; Masanobu Mizuguchi; Kazuma Fujimoto; Ryuichi Iwakiri; Akifumi Ootani; Seiji Tsunada; Shinichi Ogata; Hibiki Ootani; Ryo Shimoda; Kanako Yamaguchi; Yasuhisa Sakata

    2006-01-01

    AIM: Rectal carcinoid tumors smaller than 10 mm can be resected with local excision using endoscopy. In order to remove rectal carcinoid tumors completely, we evaluated endoscopic mucosal resection with a ligation device in this pilot control randomized study.METHODS: Fifteen patients were diagnosed with rectal carcinoid tumor (less than 10 mm) in our hospital from 1993 to 2002. There were 9 males and 6 females,with a mean age 61.5 years (range, 34-77 years).The patientshad no complaints of carcinoid syndrome symptoms. Fifteen patients were randomly divided into 2 groups: 7 carcinoid tumors were treated by conventional endoscopic resection, and 8 carcinoid tumors were treated by endoscopic resection using a ligation device.RESULTS: All rectal carcinoid tumors were located at the middle to distal rectum. The size of the tumors varied from 3 mm to 10 mm and background characteristics of the patients were not different in the two groups.The rate of complete removal of carcinoid tumors using a ligation device (100%, 8/8) was significantly higher than that of conventional endoscopic resection (57.1%,4/7). The three patients had tumor involvement of deep margin, for which additional treatment was performed.No complications occurred during or after endoscopic resection using a ligation device. All patients in the both groups were alive during the 3-year observation period.CONCLUSION: Endoscopic resection using a ligation device is a useful and safe method for resection of small rectal carcinoid tumors.

  10. Alterations in plaque accumulation and gingival inflammation promoted by treatment with self-ligating and conventional orthodontic brackets

    Directory of Open Access Journals (Sweden)

    Mauricio de Almeida Cardoso

    2015-04-01

    Full Text Available OBJECTIVE: The aim of the present study was to evaluate, comparatively, the periodontal response during orthodontic treatment performed with self-ligating and conventional brackets. METHODS: Sixteen Caucasian individuals of both sexes, aged between 12 and 16 years old and in permanent dentition were selected. Eight individuals were treated with conventional brackets installed on the lower dental arch and self-ligating brackets on the upper arch. Another eight individuals received self-ligating brackets in the lower arch and conventional brackets in the upper arch. The subjects received material and instructions for oral hygiene. Visible plaque index (VPI, gingival bleeding index (GBI and clinical attachment level (CAL were evaluated just after installation of orthodontic appliances, and 30, 60 and 180 days later. Mann-Whitney test was used to compare differences between groups (self-ligating and conventional, two-way ANOVA followed by Tukey's test was used to assess CAL at each site of each tooth. Significance level was set at 5%. RESULTS: No significant changes were found with regard to the assessed parameters (VPI, GBI and CAL in either one of the systems. CONCLUSION: No significant changes were found with regard to the periodontal response to orthodontic treatment for the variables assessed and between subjects receiving passive self-ligating and conventional brackets. All individuals had received oral hygiene instructions and had their periodontal conditions monitored.

  11. Caracterização espectral de Paspalum notatum em diferentes níveis de adubação nitrogenada Spectral characterization of Paspalum notatum under different nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Eliana Lima da Fonseca

    2002-03-01

    Full Text Available As propriedades espectrais da vegetação podem ser utilizadas para o monitoramento das condições de crescimento da vegetação ao longo do ano, assim como a estimativa da produtividade das espécies, por meio de técnicas de sensoriamento remoto. Para tanto, é necessário, primeiramente, caracterizar espectralmente as espécies que compõem a vegetação de um ecossistema. O objetivo deste trabalho foi caracterizar a reflectância do Paspalum notatum Flügge var. notatum crescendo em diferentes níveis de adubação nitrogenada. Foi realizado um experimento de campo na Estação Experimental Agronômica da Universidade Federal do Rio Grande do Sul (30º5'22'' S e 51º39'8'' W, utilizando-se um espectrorradiômetro portátil, em parcelas de P. notatum adubadas com 0, 200 e 400 kg ha-1 de N. A resposta espectral do P. notatum foi alterada pelas variações na quantidade de biomassa do dossel, provocadas por diferenças nos níveis de adubação nitrogenada. Os aumentos na quantidade de biomassa provocaram diminuição da reflectância na porção visível do espectro e aumento na porção infravermelho, o que mostra que a análise da reflectância é um bom indicador das mudanças que ocorrem em um dossel.Remote sensing techniques using spectral properties of canopies may be used to monitor vegetation growth conditions throughout the year, as well as to estimate the yield of different species. However, before these techniques can be used, it is necessary to establish the spectral properties of each of the different species which make up the landscape. The objective of this study was to characterize the spectral reflectance of Paspalum notatum Flügge var. notatum, growing on different levels of nitrogen fertilization. A field experiment was carried out at the Agronomic Experimental Station of Universidade Federal do Rio Grande do Sul, Brazil (30º5'22'' S, 51º39''8'' W, using a portable spectroradiometer, on plots with P. notatum fertilized

  12. Peripancreatic artery ligation and artery infusion chemotherapy for advanced pancreatic carcinoma

    Institute of Scientific and Technical Information of China (English)

    纪宗正; 王永向; 陈熹; 吴涛

    2003-01-01

    Objective To develop a new treatment for advanced pancreatic carcinoma. Methods Twenty-nine patients with advanced pancreatic carcinoma (12 patients with liver metastasis at the same time) were randomly divided into two groups. In group A (n=11), patients underwent bilio-enterostomy and/or gastro-enterostomy combined with systemic chemotherapy after surgery. In group B (n=18), patients underwent bilio-enterostomy and/or gastro-enterostomy combined with peripancreatic arterial ligation and arterial infusion regional chemotherapy. Twenty-four patients were followed up for 3-18 months. The palliation of clinical symptoms, changes in carcinoma size by B ultrasound (BUS) and CT scan, survival period and serum carcinoembryonic antigen (CEA) were observed and compared between the two groups. Results Symptoms were alleviated in most patients in group B, and BUS and CT scan showed that tumor volume decreased in group B. The response rate was 66.7% in group B and 18.2% in group A (P0.05). Conclusion Peripancreatic arterial ligation combined with arterial infusion regional chemotherapy is effective against both pancreatic carcinoma and with liver metastases. It can alleviate clinical symptoms, postpone the growth rate of tumor and prolong the survival period.

  13. Rubber band ligation for 750 cases of symptomatic hemorrhoids out of 2200 cases

    Institute of Scientific and Technical Information of China (English)

    Ayman M El Nakeeb; Hisham H Abd Elmoniam; Waiel W Khafagy; Mosaad H Horshed; Ramadan E El Lithy; Mohamed E Farid; Amir A Fikry; Waleed H Omar; Elyamani M Fouda; Tito A El Metwally; Hosam E Ghazy; Sabry A Badr; Mohmed Y Abu Elkhar; Salih M Elawady

    2008-01-01

    AIM: To study the results for the treatment of symptomatic hemorrhoids using rubber band ligation (RBL) method. METHODS: A retrospective study for 750 patients who came to the colorectal unit from June, 1998 to September, 2006, data was retrieved from archived files. RBL was performed using the Mc Gown applicator on an outpatient basis. The patients were asked to return to out-patient clinic for follow up at 2 wk, 1 mo, 6 mo and through telephone call every 6 mo for 2 years). RESULTS: After RBL, 696 patients (92.8%) were cured with no difference in outcome for second or third degree hemorrhoids (P = 0.31). Symptomatic recurrence was detected in 11.04% after 2 years. A total of 52 patients (6.93%) had 77 complications from RBL which required no hospitalization. Complications were pain, rectal bleeding and vaso-vagal symptoms (4.13%, 4.13% and 1.33% of patients, respectively). At 1 mo there were a significant improvement in mean SF-36 scores over baseline in five items, while after 2 years there were improvement in all items over baseline, but not significant. No significant manometeric changes after band ligation. CONCLUSION: RBL is a simple, safe and effective method for treating symptomatic second and third degree hemorrhoids as an out patient procedure with significant improvement in quality of life. RBL doesn't alter ano-rectal functions.

  14. Comparative study of torque expression among active and passive self-ligating and conventional brackets

    Science.gov (United States)

    Franco, Érika Mendonça Fernandes; Valarelli, Fabrício Pinelli; Fernandes, João Batista; Cançado, Rodrigo Hermont; de Freitas, Karina Maria Salvatore

    2015-01-01

    Abstract Objective: The aim of this study was to compare torque expression in active and passive self-ligating and conventional brackets. Methods: A total of 300 segments of stainless steel wire 0.019 x 0.025-in and six different brands of brackets (Damon 3MX, Portia, In-Ovation R, Bioquick, Roth SLI and Roth Max) were used. Torque moments were measured at 12°, 24°, 36° and 48°, using a wire torsion device associated with a universal testing machine. The data obtained were compared by analysis of variance followed by Tukey test for multiple comparisons. Regression analysis was performed by the least-squares method to generate the mathematical equation of the optimal curve for each brand of bracket. Results: Statistically significant differences were observed in the expression of torque among all evaluated bracket brands in all evaluated torsions (p bracket presented the highest torque expression up to 36° torsion. Conclusions: The connection system between wire/bracket (active, passive self-ligating or conventional with elastic ligature) seems not to interfere in the final torque expression, the latter being probably dependent on the interaction between the wire and the bracket chosen for orthodontic mechanics. PMID:26691972

  15. Analysis of microRNA signatures using size-coded ligation-mediated PCR

    Science.gov (United States)

    Arefian, Ehsan; Kiani, Jafar; Soleimani, Masoud; Shariati, S. Ali M.; Aghaee-Bakhtiari, Seyed Hamid; Atashi, Amir; Gheisari, Yousof; Ahmadbeigi, Naser; Banaei-Moghaddam, Ali M.; Naderi, Mahmood; Namvarasl, Nabiolah; Good, Liam; Faridani, Omid R.

    2011-01-01

    The expression pattern and regulatory functions of microRNAs (miRNAs) are intensively investigated in various tissues, cell types and disorders. Differential miRNA expression signatures have been revealed in healthy and unhealthy tissues using high-throughput profiling methods. For further analyses of miRNA signatures in biological samples, we describe here a simple and efficient method to detect multiple miRNAs simultaneously in total RNA. The size-coded ligation-mediated polymerase chain reaction (SL-PCR) method is based on size-coded DNA probe hybridization in solution, followed-by ligation, PCR amplification and gel fractionation. The new method shows quantitative and specific detection of miRNAs. We profiled miRNAs of the let-7 family in a number of organisms, tissues and cell types and the results correspond with their incidence in the genome and reported expression levels. Finally, SL-PCR detected let-7 expression changes in human embryonic stem cells as they differentiate to neuron and also in young and aged mice brain and bone marrow. We conclude that the method can efficiently reveal miRNA signatures in a range of biological samples. PMID:21486750

  16. Pathogen detection in milk samples by ligation detection reaction-mediated universal array method.

    Science.gov (United States)

    Cremonesi, P; Pisoni, G; Severgnini, M; Consolandi, C; Moroni, P; Raschetti, M; Castiglioni, B

    2009-07-01

    This paper describes a new DNA chip, based on the use of a ligation detection reaction coupled to a universal array, developed to detect and analyze, directly from milk samples, microbial pathogens known to cause bovine, ovine, and caprine mastitis or to be responsible for foodborne intoxication or infection, or both. Probes were designed for the identification of 15 different bacterial groups: Staphylococcus aureus, Streptococcus agalactiae, nonaureus staphylococci, Streptococcus bovis, Streptococcus equi, Streptococcus canis, Streptococcus dysgalactiae, Streptococcus parauberis, Streptococcus uberis, Streptococcus pyogenes, Mycoplasma spp., Salmonella spp., Bacillus spp., Campylobacter spp., and Escherichia coli and related species. These groups were identified based on the 16S rRNA gene. For microarray validation, 22 strains from the American Type Culture Collection or other culture collections and 50 milk samples were tested. The results demonstrated high specificity, with sensitivity as low as 6 fmol. Moreover, the ligation detection reaction-universal array assay allowed for the identification of Mycoplasma spp. in a few hours, avoiding the long incubation times of traditional microbiological identification methods. The universal array described here is a versatile tool able to identify milk pathogens efficiently and rapidly. PMID:19528580

  17. CD28 ligation increases macrophage suppression of T-cell proliferation.

    Science.gov (United States)

    Silberman, Daniel; Bucknum, Amanda; Bartlett, Thomas; Composto, Gabriella; Kozlowski, Megan; Walker, Amanda; Werda, Amy; Cua, Jackelyn; Sharpe, Arlene H; Somerville, John E; Riggs, James E

    2012-07-01

    When compared to spleen or lymph node cells, resident peritoneal cavity cells respond poorly to T-cell activation in vitro. The greater proportional representation of macrophages in this cell source has been shown to actively suppress the T-cell response. Peritoneal macrophages exhibit an immature phenotype (MHC class II(lo), B7(lo)) that reduces their efficacy as antigen-presenting cells. Furthermore, these cells readily express inducible nitric oxide synthase (iNOS), an enzyme that promotes T-cell tolerance by catabolism of the limiting amino acid arginine. Here, we investigate the ability of exogenous T-cell costimulation to recover the peritoneal T-cell response. We show that CD28 ligation failed to recover the peritoneal T-cell response and actually suppressed responses that had been recovered by inhibiting iNOS. As indicated by cytokine ELISpot and neutralizing monoclonal antibody (mAb) treatment, this 'cosuppression' response was due to CD28 ligation increasing the number of interferon (IFN)-γ-secreting cells. Our results illustrate that cellular composition and cytokine milieu influence T-cell costimulation biology.Cellular & Molecular Immunology advance online publication, 23 April 2012; doi:10.1038/cmi.2012.13.

  18. Simultaneous bile duct and portal venous branch ligation in two-stage hepatectomy

    Institute of Scientific and Technical Information of China (English)

    Hiroya Iida; Chiaki Yasui; Tsukasa Aihara; Shinichi Ikuta; Hidenori Yoshie; Naoki Yamanaka

    2011-01-01

    Hepatectomy is an effective surgical treatment for multiple bilobar liver metastases from colon cancer; however, one of the primary obstacles to completing surgical resection for these cases is an insufficient volume of the future remnant liver, which may cause postoperative liver failure. To induce atrophy of the unilateral lobe and hypertrophy of the future remnant liver, procedures to occlude the portal vein have been conventionally used prior to major hepatectomy. We report a case of a 50-year-old woman in whom two-stage hepatectomy was performed in combination with intraoperative ligation of the portal vein and the bile duct of the right hepatic lobe. This procedure was designed to promote the atrophic effect on the right hepatic lobe more effectively than the conventional technique, and to the best of our knowledge, it was used for the first time in the present case. Despite successful induction of liver volume shift as well as the following procedure, the patient died of subsequent liver failure after developing recurrent tumors. We discuss the first case in which simultaneous ligation of the portal vein and the biliary system was successfully applied as part of the first step of two-stage hepatectomy.

  19. Comparative study of torque expression among active and passive self-ligating and conventional brackets

    Directory of Open Access Journals (Sweden)

    Érika Mendonça Fernandes Franco

    2015-12-01

    Full Text Available Abstract Objective: The aim of this study was to compare torque expression in active and passive self-ligating and conventional brackets. Methods: A total of 300 segments of stainless steel wire 0.019 x 0.025-in and six different brands of brackets (Damon 3MX, Portia, In-Ovation R, Bioquick, Roth SLI and Roth Max were used. Torque moments were measured at 12°, 24°, 36° and 48°, using a wire torsion device associated with a universal testing machine. The data obtained were compared by analysis of variance followed by Tukey test for multiple comparisons. Regression analysis was performed by the least-squares method to generate the mathematical equation of the optimal curve for each brand of bracket. Results: Statistically significant differences were observed in the expression of torque among all evaluated bracket brands in all evaluated torsions (p < 0.05. It was found that Bioquick presented the lowest torque expression in all tested torsions; in contrast, Damon 3MX bracket presented the highest torque expression up to 36° torsion. Conclusions: The connection system between wire/bracket (active, passive self-ligating or conventional with elastic ligature seems not to interfere in the final torque expression, the latter being probably dependent on the interaction between the wire and the bracket chosen for orthodontic mechanics.

  20. Sequencing by ligation variation with endonuclease V digestion and deoxyinosine-containing query oligonucleotides

    Directory of Open Access Journals (Sweden)

    Ho Antoine

    2011-12-01

    Full Text Available Abstract Background Sequencing-by-ligation (SBL is one of several next-generation sequencing methods that has been developed for massive sequencing of DNA immobilized on arrayed beads (or other clonal amplicons. SBL has the advantage of being easy to implement and accessible to all because it can be performed with off-the-shelf reagents. However, SBL has the limitation of very short read lengths. Results To overcome the read length limitation, research groups have developed complex library preparation processes, which can be time-consuming, difficult, and result in low complexity libraries. Herein we describe a variation on traditional SBL protocols that extends the number of sequential bases that can be sequenced by using Endonuclease V to nick a query primer, thus leaving a ligatable end extended into the unknown sequence for further SBL cycles. To demonstrate the protocol, we constructed a known DNA sequence and utilized our SBL variation, cyclic SBL (cSBL, to resequence this region. Using our method, we were able to read thirteen contiguous bases in the 3' - 5' direction. Conclusions Combining this read length with sequencing in the 5' - 3' direction would allow a read length of over twenty bases on a single tage. Implementing mate-paired tags and this SBL variation could enable > 95% coverage of the genome.

  1. Evaluating Necessity of Azygos Vein Ligation in Primary Repair of Esophageal Atresia.

    Science.gov (United States)

    Fathi, Mehdi; Joudi, Marjan; Morteza, Afsaneh

    2015-12-01

    Surgery has dramatically improved survival of infants with esophageal atresia. However, early and late complications of these surgeries affect the future life of this population. A probable step toward minimizing such complications is through modifying the technique of surgery. We evaluated two groups of esophageal atresia undergoing surgery with two different techniques including preservation and ligation of the Azygos vein and compared early complications, duration of surgery, and hospital and neonatal intensive care unit (NICU) stay between them. A total number of 24 patients with mean age of 24 to 48 h, who were diagnosed with esophageal atresia, were included in the study. All cases were randomly allocated in two groups: group A (case group) in which patients underwent surgery with preservation of the Azygos vein and group B (control group) in which patients underwent the former surgical method with ligation of the Azygos vein. Incidence of early complications, duration of surgery, and NICU and hospital stay were compared between the two groups. None of the complications occurred in either group. Duration of surgery, NICU stay, and hospital stay were not statistically significant between the groups. Preserving the Azygos vein during esophageal atresia surgery is probably a good modification of the classic technique. PMID:26730061

  2. A noncatalytic function of the ligation complex during nonhomologous end joining.

    Science.gov (United States)

    Cottarel, Jessica; Frit, Philippe; Bombarde, Oriane; Salles, Bernard; Négrel, Aurélie; Bernard, Stéphanie; Jeggo, Penny A; Lieber, Michael R; Modesti, Mauro; Calsou, Patrick

    2013-01-21

    Nonhomologous end joining is the primary deoxyribonucleic acid (DNA) double-strand break repair pathway in multicellular eukaryotes. To initiate repair, Ku binds DNA ends and recruits the DNA-dependent protein kinase (DNA-PK) catalytic subunit (DNA-PKcs) forming the holoenzyme. Early end synapsis is associated with kinase autophosphorylation. The XRCC4 (X4)-DNA Ligase IV (LIG4) complex (X4LIG4) executes the final ligation promoted by Cernunnos (Cer)-X4-like factor (XLF). In this paper, using a cell-free system that recapitulates end synapsis and DNA-PKcs autophosphorylation, we found a defect in both activities in human cell extracts lacking LIG4. LIG4 also stimulated the DNA-PKcs autophosphorylation in a reconstitution assay with purified components. We additionally uncovered a kinase autophosphorylation defect in LIG4-defective cells that was corrected by ectopic expression of catalytically dead LIG4. Finally, our data support a contribution of Cer-XLF to this unexpected early role of the ligation complex in end joining. We propose that productive end joining occurs by early formation of a supramolecular entity containing both DNA-PK and X4LIG4-Cer-XLF complexes on DNA ends. PMID:23337116

  3. Long-term outcome and efficacy of endoscopic hemorrhoid ligation for symptomatic internal hemorrhoids

    Institute of Scientific and Technical Information of China (English)

    Ming-Yao Su; Cheng-Tang Chiu; Wei-Pin Lin; Chen-Ming Hsu; Pang-Chi Chen

    2011-01-01

    AIM: To assess the long-term outcome of endoscopic hemorrhoid ligation (EHL) for the treatment of symptomatic internal hemorrhoids. METHODS: A total of 759 consecutive patients (415 males and 344 females) were enrolled. Clinical presentations were rectal bleeding (593 patients) and mucosal prolapse (166 patients). All patients received EHL at outpatient clinics. Hemorrhoid severity was classified by Goligher's grading. The mean follow-up period was 55.4 mo (range, 45-92 mo). RESULTS: The number of band ligations averaged 2.35 in the first session for bleeding and 2.69 for prolapsed patients. Bleeding was controlled in 587 (98.0%) patients, while prolapse was reduced in 137 (82.5%) patients. After treatment, 93 patients experienced anal pain and 48 patients had mild bleeding. Patient subjective satisfaction was 93.6%. Repeat treatment or surgery was performed if symptoms were not relieved in the first session. In the bleeding group, the recurrence rate was 3.7% (22 patients) at 1 year, and 6.6% and 13.0% at 2 and 5 years. In the prolapsed group, the recurrence rate was 3.0%, 9.6% and 16.9% at 1, 2 and 5 years, respectively. CONCLUSION: EHL is an easy and well-tolerated procedure for the treatment of symptomatic internal hemorrhoids, with good long-term results.

  4. Glyoxalase-1 overexpression partially prevents diabetes-induced impaired arteriogenesis in a rat hindlimb ligation model.

    Science.gov (United States)

    Brouwers, Olaf; Yu, Liang; Niessen, Petra; Slenter, Jos; Jaspers, Karolien; Wagenaar, Allard; Post, Mark; Miyata, Toshio; Backes, Walter; Stehouwer, Coen; Huijberts, Maya; Schalkwijk, Casper

    2016-08-01

    We hypothesize that diabetes-induced impaired collateral formation after a hindlimb ligation in rats is in part caused by intracellular glycation and that overexpression of glyoxalase-I (GLO-I), i.e. the major detoxifying enzyme for advanced-glycation-endproduct (AGE) precursors, can prevent this. Wild-type and GLO-I transgenic rats with or without diabetes (induced by 55 mg/kg streptozotocin) were subjected to ligation of the right femoral artery. Laser Doppler perfusion imaging showed a significantly decreased blood perfusion recovery after 6 days in the diabetic animals compared with control animals, without any effect of Glo1 overexpression. In vivo time-of-flight magnetic resonance angiography at 7-Tesla showed a significant decrease in the number and volume of collaterals in the wild-type diabetic animals compared with the control animals. Glo1 overexpression partially prevented this decrease in the diabetic animals. Diabetes-induced impairment of arteriogenic adaptation can be partially rescued by overexpressing of GLO-I, indicating a role of AGEs in diabetes-induced impaired collateral formation. PMID:27296676

  5. Comparison of emergency endoscopic variceal ligation plus octride or octride alone for acute esophageal variceal bleeding

    Institute of Scientific and Technical Information of China (English)

    LIU Jin-song; LIU Jun

    2009-01-01

    Background Octride was the main method for the treatment of esophageal variceal bleeding (EVB). The aim of this study was to compare the cost-effect and safety between esophageal variceal ligation (EVL) plus octride and octride alone in acute esophageal bleeding.Methods A total of 101 cirrhotic patients with EVB were involved in this study and received emergency EVL+octride (EVL group) or only octride therapy randomly. The cost, efficacy and safety were analyzed and compared between the two groups.Results Among 51 patients in EVL group, 5 (10%) patients failed. Among 50 patients in the octride treatment group, 13 patients (26%) failed. The difference was significant (P<0.05). The average blood transfusion volume was (2.4±2.2) units in the EVL group and (6.4±3.4) units in the octride treatment group (P <0.05). Hospital stay was (7.4±1.3) days in the EVL group and (11.4±3.3) days in the octride treatment group (P<0.05). The average hospital cost was (10 983±1147) yuan in the EVL group and (13 921 ±2107) yuan in the octride treatment group (P<0.05). Conclusion Emergency endoscopic ligation plus octride is superior to octride alone in the treatment of acute EVB with lower cost and higher efficacy with enough safety.

  6. Risk factors for predicting early variceal rebleeding after endoscopic variceal ligation

    Institute of Scientific and Technical Information of China (English)

    Liang Xu; Feng Ji; Qin-Wei Xu; Mie-Qing Zhang

    2011-01-01

    AIM: To analyze the clinical risk factors for early variceal rebleeding after endoscopic variceal ligation (EVL). METHODS: 342 cirrhotic patients with esophageal varices who received elective EVL to prevent bleeding or rebleeding at our endoscopy center between January 2005 and July 2010. were included in this study. The early rebleeding cases after EVL were confirmed by clinical signs or endoscopy. A case-control study was performed comparing the patients presenting with early rebleeding with those without this complication. RESULTS: The incidence of early rebleeding after EVL was 7.60%, and the morbidity of rebleeding was 26.9%. Stepwise multivariate logistic regression analysis showed that four variables were independent risk factors for early rebleeding: moderate to excessive ascites [odds ratio (OR) 62.83, 95% CI: 9.39-420.56, P 18 s (OR 11.35, 95% CI: 1.93-66.70, P = 0.007). CONCLUSION: The early rebleeding rate after EVL is mainly affected by the volume of ascites, number of rubber bands used to ligate, severity of varices and prolonged PT. Effective measures for prevention and treatment should be adopted before and after EVL.

  7. Controlling tetramer formation, subunit rotation and DNA ligation during Hin-catalyzed DNA inversion.

    Science.gov (United States)

    Chang, Yong; Johnson, Reid C

    2015-07-27

    Two critical steps controlling serine recombinase activity are the remodeling of dimers into the chemically active synaptic tetramer and the regulation of subunit rotation during DNA exchange. We identify a set of hydrophobic residues within the oligomerization helix that controls these steps by the Hin DNA invertase. Phe105 and Met109 insert into hydrophobic pockets within the catalytic domain of the same subunit to stabilize the inactive dimer conformation. These rotate out of the catalytic domain in the dimer and into the subunit rotation interface of the tetramer. About half of residue 105 and 109 substitutions gain the ability to generate stable synaptic tetramers and/or promote DNA chemistry without activation by the Fis/enhancer element. Phe106 replaces Phe105 in the catalytic domain pocket to stabilize the tetramer conformation. Significantly, many of the residue 105 and 109 substitutions support subunit rotation but impair ligation, implying a defect in rotational pausing at the tetrameric conformer poised for ligation. We propose that a ratchet-like surface involving Phe105, Met109 and Leu112 within the rotation interface functions to gate the subunit rotation reaction. Hydrophobic residues are present in analogous positions in other serine recombinases and likely perform similar functions. PMID:26056171

  8. Simulation of Soil-Plant Nitrogen Interactions for Educational Purposes.

    Science.gov (United States)

    Huck, M. G.; Hoeft, R. G.

    1994-01-01

    Describes a computer model characterizing the balance of soil-plant Nitrogen that allows students to see the likely consequences of different biological and weather-related parameters. Proposes three uses for the model: (1) orienting beginning students to understand the soil Nitrogen cycle; (2) providing information for advanced students; and (3)…

  9. Estimation of infarct size by determination of myocardial 3H-tetracycline accumulation in the coronary ligated rat

    International Nuclear Information System (INIS)

    Myocardial infarction was produced in rats by ligation of the left coronary artery. Rats were injected with 3H-tetracycline (50 muCi/kg) i.p., 10 minutes prior to ligation. The rats were killed at various time periods after ligation and the myocardial accumulation of 3H-tetracycline determined in the left ventricle or in whole heart homogenates. CPK was also determined in the myocardium or serum. Myocardial 3H-tetracycline was not significantly elevated in the whole heart homogenates. However, there was a significant increase in 3H-tetracycline in the digests of the left ventricle 6 h post-infarct. This increase correlated very well with serum CPK activity. This suggest that this method could be a useful tool in the estimation of infarct size

  10. Superantigen and HLA-DR ligation induce phospholipase-C gamma 1 activation in class II+ T cells

    DEFF Research Database (Denmark)

    Kanner, S B; Odum, Niels; Grosmaire, L;

    1992-01-01

    activated by HLA-DR ligation through antibody cross-linking or by direct enterotoxin superantigen binding. Both types of stimuli induced tyrosine phosphorylation of phosphatidylinositol-specific phospholipase C gamma 1 (PLC gamma 1) and an increase in intracellular calcium concentration; however......, superantigen-induced signaling was stronger than class II ligation alone. Antibody-mediated ligation of HLA-DR with CD3 resulted in augmented PLC gamma 1 activation and increased calcium mobilization, consistent with a mechanism of superantigen activity through a combination of class II and CD3/Ti signals...... to the PLC gamma 1 signal transduction pathway, and that coligation of HLA-DR with CD3 augments T cell signaling comparable to that induced by enterotoxin superantigen. Thus, we suggest that superantigen-induced early signaling responses in activated T cells may be due in part to class II transmembrane...

  11. Hydrolytic Amino Acids Employed as a Novel Organic Nitrogen Source for the Preparation of PGPF-Containing Bio-Organic Fertilizer for Plant Growth Promotion and Characterization of Substance Transformation during BOF Production.

    Directory of Open Access Journals (Sweden)

    Fengge Zhang

    Full Text Available Opportunity costs seriously limit the large-scale production of bio-organic fertilizers (BOFs both in China and internationally. This study addresses the utilization of amino acids resulting from the acidic hydrolysis of pig corpses as organic nitrogen sources to increase the density of TrichodermaharzianumT-E5 (a typical plant growth-promoting fungi, PGPF. This results in a novel, economical, highly efficient and environmentally friendly BOF product. Fluorescence excitation-emission matrix (EEM spectroscopy combined with fluorescence regional integration (FRI was employed to monitor compost maturity levels, while pot experiments were utilized to test the effects of this novel BOF on plant growth. An optimization experiment, based on response surface methodologies (RSMs, showed that a maximum T-E5 population (3.72 × 108 ITS copies g-1 was obtained from a mixture of 65.17% cattle manure compost (W/W, 19.33% maggot manure (W/W, 15.50% (V/Whydrolytic amino acid solution and 4.69% (V/W inoculum at 28.7°C after a 14 day secondary solid fermentation. Spectroscopy analysis revealed that the compost transformation process involved the degradation of protein-like substances and the formation of fulvic-like and humic-like substances. FRI parameters (PI, n, PII, n, PIII, n and PV, n were used to characterize the degree of compost maturity. The BOF resulted in significantly higher increased chlorophyll content, shoot length, and shoot and root dry weights of three vegetables (cucumber, tomato and pepper by 9.9%~22.4%, 22.9%~58.5%, 31.0%~84.9%, and 24.2%~34.1%, respectively. In summary, this study presents an operational means of increasing PGPF T-E5 populations in BOF to promote plant growth with a concomitant reduction in production cost. In addition, a BOF compost maturity assessment using fluorescence EEM spectroscopy and FRI ensured its safe field application.

  12. Stability of a rat model of prehepatic portal hypertension caused by partial ligation of the portal vein

    Institute of Scientific and Technical Information of China (English)

    Zhe Wen; Jin-Zhe Zhang; Hui-Min Xia; Chun-Xiao Yang; Ya-Jun Chen

    2009-01-01

    AIM:To study the stability of portal hypertension (PHT) caused by partial ligation of the portal vein ligation (PVL) in a rat model.METHODS:Thirty male adult Wistar rats were divided into two groups:10 in Group Ⅰ received a sham operation;and 20 in Group Ⅱ received partial PVL.Portal vein pressure (PVP) was measured at four time periods:before ligation,2 wk,6 wk and 10 wk postsurgery.Portal venography,blood sampling and liver and spleen pathological examinations were conducted at 10 wk after surgery.RESULTS:The PVP was 9.15±0.58 cmH2O before ligation,and increased to 17.32±0.63 cmH2O 2 wk after PVL.By repeat measurement of the PVP in each rat,it was shown to remain elevated for 10 wk.There were no significant differences in the pressure measurements at 2 wk,6 wk and 10 wk.Varices were found mainly in the mesenteric vein 2 wk after PVL,which were more obvious later,while these manifestations were similar at week 6 and week 10.Portal venography demonstrated the varices and collaterals.There was no significant change in liver pathology.The volume of the spleen was enlarged 2-fold after ligation,and the sinus of the spleen was enlarged due to congestion.Significant sinus endothelial cell proliferation was observed,but no evidence of hypersplenia was found on hemogram and biochemical examination.CONCLUSION:These findings suggest that a satisfactory prehepatic PHT rat model can be obtained by partial ligation of the portal vein,and this PHT rat model was stable for at least 10 wk.

  13. Nitrogen trading tool

    Science.gov (United States)

    The nitrogen cycle is impacted by human activities, including those that increase the use of nitrogen in agricultural systems, and this impact can be seen in effects such as increased nitrate (NO3) levels in groundwater or surface water resources, increased concentration of nitrous oxide (N2O) in th...

  14. Nitrogen use efficiency (NUE)

    NARCIS (Netherlands)

    Oenema, O.

    2015-01-01

    There is a need for communications about resource use efficiency and for measures to increase the use efficiency of nutrients in relation to food production. This holds especially for nitrogen. Nitrogen (N) is essential for life and a main nutrient element. It is needed in relatively large quantitie

  15. Protective effect of ginger oil on aspirin and pylorus ligation-induced gastric ulcer model in rats

    Directory of Open Access Journals (Sweden)

    Khushtar M

    2009-01-01

    Full Text Available The present investigation was performed in aspirin and pylorus ligation-induced ulcer model in Wistar rats, in which ability of ginger oil to provide gastric protection was studied at two different doses, 0.5 and 1 g/kg po. Gastric protection was evaluated by measuring the ulcer index, serum λ- GTP levels, total acidity of gastric juice and gastric wall mucus thickness. The results obtained in the present study indicated that ginger oil has a protective action against gastric ulcers induced by aspirin plus pylorus ligation in Wistar rats.

  16. Reversible recruitment and emission of DO3A-derived lanthanide complexes at ligating molecular films on gold.

    Science.gov (United States)

    Lehr, Joshua; Bennett, Jamie; Tropiano, Manuel; Sørensen, Thomas J; Faulkner, Stephen; Beer, Paul D; Davis, Jason J

    2013-02-01

    The recruitment of DO3A-derived lanthanide complexes by ligation to isophthalic acid and catechol-modified gold surfaces, and their resulting sensitization, is reported herein. Predictably pH-dependent surface recruitment is associated with the expected fingerprint europium and terbium emission characteristics. The intensity of the lanthanide luminescence scales exponentially with spacer length, indicating a strong quenching interaction between the lanthanide and the gold surface. The switchable catechol oxidation state provides a means of electrochemically triggering the release of prior ligated complexes. PMID:23320931

  17. Nitrogen in Chinese coals

    Science.gov (United States)

    Wu, D.; Lei, J.; Zheng, B.; Tang, X.; Wang, M.; Hu, Jiawen; Li, S.; Wang, B.; Finkelman, R.B.

    2011-01-01

    Three hundred and six coal samples were taken from main coal mines of twenty-six provinces, autonomous regions, and municipalities in China, according to the resource distribution and coal-forming periods as well as the coal ranks and coal yields. Nitrogen was determined by using the Kjeldahl method at U. S. Geological Survey (USGS), which exhibit a normal frequency distribution. The nitrogen contents of over 90% Chinese coal vary from 0.52% to 1.41% and the average nitrogen content is recommended to be 0.98%. Nitrogen in coal exists primarily in organic form. There is a slight positive relationship between nitrogen content and coal ranking. ?? 2011 Science Press, Institute of Geochemistry, CAS and Springer Berlin Heidelberg.

  18. The preparation and characterization of Cu(II complexes with N,N’,N”,N’”-tetrakis(2-pyridylmethyl-1,4,8,11-tetraazacyclotetradecane and 2,6-diacetylpyridine bis(semi/thiosemicarbazones

    Directory of Open Access Journals (Sweden)

    GORDANA VUCKOVIC

    2004-03-01

    Full Text Available Two new Cu(II mixed-ligand complexes with octadentate N,N’,N”,N’”-tetrakis(2-pyridylmethyl-1,4,8,11-tetraazacyclotetradecane (tpmc and potentially pentadentate ligands 2,6-diacetylpyridine bis(semicarbazone (DAPsc2 or 2,6-diacetylpyridine bis(thiosemicarbazone (DAPtsc2 were prepared. The general formulas: [Cu4 DAPsc2(tpmc2]ClO48·5CH3COCH3·H2O and [Cu2 DAPtsc2(tpmc](ClO44·7C2H5OH were proposed on the basis of elemental analyses and conductometric measurements. The complexes were characterized by magnetic measurement, electronic absorption and IR spectroscopy. For the dinuclear complex, an exo coordination of Cu(II with four nitrogens from tpmc and m-bonded DAPtsc2 through sulfurs and possibly terminal hydrazinic (azomethine nitrogens is assumed. For the tetranuclear complex, it is supposed that one DAPsc2 bridges two [Cu2 tpmc]4+ units using oxygens and terminal hydrazinic nitrogens as ligators. Finally, some antibacterial activity of the complexes was found.

  19. Analysis of nitrogen species in titanium oxynitride ALD films

    Science.gov (United States)

    Sowińska, Małgorzata; Brizzi, Simone; Das, Chittaranjan; Kärkkänen, Irina; Schneidewind, Jessica; Naumann, Franziska; Gargouri, Hassan; Henkel, Karsten; Schmeißer, Dieter

    2016-09-01

    Titanium oxynitride films are prepared by plasma enhanced atomic layer deposition method using two different precursors and nitrogen sources. Synchrotron radiation-based X-ray photoelectron spectroscopy and X-ray absorption spectroscopy are used to characterize the nitrogen species incorporated within these films depending on the deposition parameters. It is found that nitrogen atoms in these films are differently bonded. In particular, it can be distinguished between Tisbnd ON and Tisbnd N bonding configurations and molecular nitrogen species caused by precursor fragments.

  20. Increased secretion of insulin and proliferation of islet β-cells in rats with mesenteric lymph duct ligation

    International Nuclear Information System (INIS)

    Highlights: ► Insulin secretion was increased during the OGTT or IVGTT in mesenteric lymph duct-ligated rats. ► Proliferation of islet β-cells was upregulated in lymph duct-ligated rats. ► Mesenteric lymph duct flow has a role in glucose metabolism. -- Abstract: Background and aims: It has been suggested that intestinal lymph flow plays an important role in insulin secretion and glucose metabolism after meals. In this study, we investigated the influence of ligation of the mesenteric lymph duct on glucose metabolism and islet β-cells in rats. Methods: Male Sprague–Dawley rats (10 weeks old) were divided into two groups: one underwent ligation of the mesenteric lymph duct above the cistern (ligation group), and the other underwent a sham operation (sham group). After 1 and 2 weeks, fasting plasma concentrations of glucose, insulin, triglyceride, glucose-dependent insulinotropic polypeptide (GIP), and the active form of glucagon-like peptide-1 (GLP-1) were measured. At 2 weeks after the operation, the oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT) were performed. After the rats had been sacrificed, the insulin content of the pancreas was measured and the proliferation of β-cells was assessed immunohistochemically using antibodies against insulin and Ki-67. Results: During the OGTT, the ligation group showed a significant decrease in the plasma glucose concentration at 120 min (p < 0.05) and a significant increase in the plasma insulin concentration by more than 2-fold at 15 min (p < 0.01). On the other hand, the plasma GIP concentration was significantly decreased at 60 min (p < 0.01) in the ligated group, while the active form of GLP-1 showed a significantly higher level at 90 min (1.7-fold; p < 0.05) and 120 min (2.5-fold; p < 0.01). During the IVGTT, the plasma insulin concentration in the ligation group was significantly higher at 2 min (more than 1.4-fold; p < 0.05). Immunohistochemistry showed that the ratios of

  1. Increased secretion of insulin and proliferation of islet {beta}-cells in rats with mesenteric lymph duct ligation

    Energy Technology Data Exchange (ETDEWEB)

    Nagino, Ko; Yokozawa, Junji; Sasaki, Yu; Matsuda, Akiko; Takeda, Hiroaki [Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585 (Japan); Kawata, Sumio, E-mail: Sumio_Kawata@pref.hyogo.lg.jp [Department of Gastroenterology, Faculty of Medicine, Yamagata University, Yamagata 990-9585 (Japan); Hyogo Prefectural Nishinomiya Hospital, 13-9 Rokutanji-cho, Nishinomiya 662-0918 (Japan)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Insulin secretion was increased during the OGTT or IVGTT in mesenteric lymph duct-ligated rats. Black-Right-Pointing-Pointer Proliferation of islet {beta}-cells was upregulated in lymph duct-ligated rats. Black-Right-Pointing-Pointer Mesenteric lymph duct flow has a role in glucose metabolism. -- Abstract: Background and aims: It has been suggested that intestinal lymph flow plays an important role in insulin secretion and glucose metabolism after meals. In this study, we investigated the influence of ligation of the mesenteric lymph duct on glucose metabolism and islet {beta}-cells in rats. Methods: Male Sprague-Dawley rats (10 weeks old) were divided into two groups: one underwent ligation of the mesenteric lymph duct above the cistern (ligation group), and the other underwent a sham operation (sham group). After 1 and 2 weeks, fasting plasma concentrations of glucose, insulin, triglyceride, glucose-dependent insulinotropic polypeptide (GIP), and the active form of glucagon-like peptide-1 (GLP-1) were measured. At 2 weeks after the operation, the oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT) were performed. After the rats had been sacrificed, the insulin content of the pancreas was measured and the proliferation of {beta}-cells was assessed immunohistochemically using antibodies against insulin and Ki-67. Results: During the OGTT, the ligation group showed a significant decrease in the plasma glucose concentration at 120 min (p < 0.05) and a significant increase in the plasma insulin concentration by more than 2-fold at 15 min (p < 0.01). On the other hand, the plasma GIP concentration was significantly decreased at 60 min (p < 0.01) in the ligated group, while the active form of GLP-1 showed a significantly higher level at 90 min (1.7-fold; p < 0.05) and 120 min (2.5-fold; p < 0.01). During the IVGTT, the plasma insulin concentration in the ligation group was significantly higher at 2

  2. Plaque retention by self-ligating vs elastomeric orthodontic brackets: quantitative comparison of oral bacteria and detection with adenosine triphosphate-driven bioluminescence.

    NARCIS (Netherlands)

    Pellegrini, P.; Sauerwein, R.W.; Finlayson, T.; McLeod, J.; Covell, D.A.; Maier, T.; Machida, C.A.

    2009-01-01

    INTRODUCTION: Enamel decalcification is a common problem in orthodontics. The objectives of this randomized clinical study were to enumerate and compare plaque bacteria surrounding 2 bracket types, self-ligating (SL) vs elastomeric ligating (E), and to determine whether adenosine triphosphate (ATP)-

  3. Effects of urban stream burial on nitrogen uptake and ecosystem metabolism: implications for watershed nitrogen and carbon fluxes

    Science.gov (United States)

    Urbanization has resulted in extensive burial and channelization of headwater streams, yet little is known about impacts on stream ecosystem functions critical for reducing downstream nitrogen pollution. To characterize the biogeochemical impact of stream burial, we measured NO3...

  4. Modeling nitrogen fluxes in Germany - where does the nitrogen go?

    Science.gov (United States)

    Klement, Laura; Bach, Martin; Breuer, Lutz

    2016-04-01

    According to the latest inventory of the EU Water Framework Directive, 26.3% of German groundwater bodies are in a poor chemical state regarding nitrate. Additionally, the EU initiated infringement proceedings against Germany for not meeting the quality standards of the EU Nitrate Directive. Agriculture has been determined as the main source of nitrate pollution due to over-fertilization and regionally high density of livestock farming. The nitrogen balance surplus is commonly used as an indicator characterizing the potential of nitrate leaching into groundwater bodies and thus also serves as a foundation to introduce legislative restrictions or to monitor the success of mitigation measures. Currently, there is an ongoing discussion which measures are suitable for reducing the risk of nitrate leaching and also to what extent. However, there is still uncertainty about just how much the nitrogen surplus has to be reduced to meet the groundwater quality standards nationwide. Therefore, the aims of our study were firstly to determine the level of the nitrogen surplus that would be acceptable at the utmost and secondly whether the currently discussed target value of 30 kg N per hectare agricultural land for the soil surface nitrogen balance would be sufficient. The models MONERIS (Modeling Nutrient Emissions in River System) and MoRE (Modelling of Regionalized Emissions), the latter based on the first, are commonly used for estimating nitrogen loads into the river system in Germany at the mesoscale, as well as the effect of mitigation measures in the context of the EU directive 2008/105/EC (Environmental quality standards applicable to surface water). We used MoRE to calculate nitrate concentration for 2759 analytical units in Germany. Main factors are the surplus of the soil surface nitrogen balance, the percolation rate and an exponent representing the denitrification in the vadose zone. The modeled groundwater nitrate concentrations did not correspond to the regional

  5. Pulmonary Functions After Injection Sclerotherapy Of Esophageal Varices & After Band Ligation

    Directory of Open Access Journals (Sweden)

    Mohamed A. Metwally*, Ahmad Abdelsadek Mohammad,**Galal A. Moawad,*.

    2013-04-01

    Full Text Available Aim of the study: To study changes in pulmonary function tests after esophageal variceal injection sclerotherapy in comparison to changes after esophageal variceal band ligation.Patients & methods:This study was designed as non randomized controlled study. Thirty patients with hepatic cirrhosis & portal hypertension who were admitted to Hepatology, Gastroenterology and Infectious Diseases department , Benha university hospital for elective esophageal variceal therapy (secondary prophylaxis were classified into group I:15 patients treated with sclerotherapy by using 5-15 ml ethanolamine oleate and group II:15 patients treated with band ligation. Patients were subjected for full clinical evaluation including history, general, chest, and abdominal examination. Laboratory and radiological investigation including complete blood count, liver function tests, kidney function tests and blood sugar and plain chest x-ray (P.A. and lateral views were done. Pulmonary function tests and arterial blood gasses were done before, one day after and one week after the procedure.Results:The results revealed , significant decrease in vital capacity in group I one day after injection ( p ˂ 0.05,but no significant decrease in vital capacity in group II. There was a significant decrease in PaO2 in group I one day after injection sclerotherapy ( p ˂ 0.05 but no significant changes in group II and no significant changes in PaCO2 in both groups one day after the procedures. The study has also revealed no significant changes in FVC,FEV1/FVC and PaCO2 in group I and group II after procedures. The study revealed significant linear correlation between the decreases in PaO2 and the percentage decrease in vital capacity( p ˂ 0.05. One week after procedure, pulmonary functions that has been affected in group I returned back to baseline values.Conclusions: esophageal injection sclerotherapy produces restrictive defect (decrease in PaO2 and vital capacity in pulmonary functions

  6. Nitrogen control in bacteria.

    Science.gov (United States)

    Merrick, M J; Edwards, R A

    1995-12-01

    Nitrogen metabolism in prokaryotes involves the coordinated expression of a large number of enzymes concerned with both utilization of extracellular nitrogen sources and intracellular biosynthesis of nitrogen-containing compounds. The control of this expression is determined by the availability of fixed nitrogen to the cell and is effected by complex regulatory networks involving regulation at both the transcriptional and posttranslational levels. While the most detailed studies to date have been carried out with enteric bacteria, there is a considerable body of evidence to show that the nitrogen regulation (ntr) systems described in the enterics extend to many other genera. Furthermore, as the range of bacteria in which the phenomenon of nitrogen control is examined is being extended, new regulatory mechanisms are also being discovered. In this review, we have attempted to summarize recent research in prokaryotic nitrogen control; to show the ubiquity of the ntr system, at least in gram-negative organisms; and to identify those areas and groups of organisms about which there is much still to learn. PMID:8531888

  7. Comparison of Frictional Forces Generated by a New Ceramic Bracket with the Conventional Brackets using Unconventional and Conventional Ligation System and the Self-ligating Brackets: An In Vitro Study

    Science.gov (United States)

    Pasha, Azam; Vishwakarma, Swati; Narayan, Anjali; Vinay, K; Shetty, Smitha V; Roy, Partha Pratim

    2015-01-01

    Background: Fixed orthodontic mechanotherapy is associated with friction between the bracket - wire - ligature interfaces during the sliding mechanics. A sound knowledge of the various factors affecting the magnitude of friction is of paramount importance. The present study was done to analyze and compare the frictional forces generated by a new ceramic (Clarity Advanced) bracket with the conventional, (metal and ceramic) brackets using unconventional and conventional ligation system, and the self-ligating (metal and ceramic) brackets in the dry condition. Materials and Methods: The various bracket wire ligation combinations were tested in dry condition. The brackets used were of 0.022″ × 0.028″ nominal slot dimension of MBT prescription: Stainless steel (SS) self-ligating bracket (SLB) of (SmartClip), SS Conventional bracket (CB) (Victory series), Ceramic SLB (Clarity SL), Conventional Ceramic bracket with metal slot (Clarity Bracket), Clarity Advanced Ceramic Brackets (Clarity™ ADVANCED, 3M Unitek). These brackets were used with two types of elastomeric ligatures: Conventional Elastomeric Ligatures (CEL) (Clear medium mini modules) and Unconventional Elastomeric Ligatures (UEL) (Clear medium slide ligatures, Leone orthodontic products). The aligning and the retraction wires were used, i.e., 0.014″ nickel titanium (NiTi) wires and 0.019″ × 0.025″ SS wires, respectively. A universal strength testing machine was used to measure the friction produced between the different bracket, archwires, and ligation combination. This was done with the use of a custom-made jig being in position. Results: Mean, standard deviation, and range were computed for the frictional values obtained. Results were subjected to statistical analysis through ANOVA. The frictional resistance observed in the new Clarity Advanced bracket with a conventional elastomeric ligature was almost similar with the Clarity metal slot bracket with a conventional elastomeric ligature. When using

  8. Marine nitrogen cycle

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.

    and particulate organic forms, respectively) and atmospheric deposition (~50 Tg N a -1 ), a substantial fraction of which is believed to be of anthropogenic (human-made) origin. Of the various loss terms of combined nitrogen from the ocean, emission of N 2 O... and nitrous oxide budgets: Moving targets as we enter the anthropocene?, Sci. Mar., 65, 85-105, 2001. Page 2 of 3Marine nitrogen cycle - Encyclopedia of Earth 11/20/2006http://www.eoearth.org/article/Marine_nitrogen_cycle square6 Gruber, N.: The dynamics...

  9. Detection of reverse transcriptase termination sites using cDNA ligation and massive parallel sequencing

    DEFF Research Database (Denmark)

    Kielpinski, Lukasz J; Boyd, Mette; Sandelin, Albin;

    2013-01-01

    of these methods can be increased by applying massive parallel sequencing technologies.Here, we describe a versatile method for detection of reverse transcriptase termination sites based on ligation of an adapter to the 3' end of cDNA with bacteriophage TS2126 RNA ligase (CircLigase™). In the following PCR......Detection of reverse transcriptase termination sites is important in many different applications, such as structural probing of RNAs, rapid amplification of cDNA 5' ends (5' RACE), cap analysis of gene expression, and detection of RNA modifications and protein-RNA cross-links. The throughput...... that do not require formal bioinformatics training. As an example, we apply the method to detection of transcription start sites in mouse liver cells....

  10. Testing the feasibility of DNA typing for human identification by PCR and an oligonucleotide ligation assay

    Energy Technology Data Exchange (ETDEWEB)

    Delahunty, C.; Ankener, W.; Deng, Qiang [Univ. of Washington, Seattle, WA (United States)] [and others

    1996-06-01

    The use of DNA typing in human genome analysis is increasing and finding widespread application in the area of forensic and paternity testing. In this report, we explore the feasibility of typing single nucleotide polymorphisms (SNPs) by using a semiautomated method for analyzing human DNA samples. In this approach, PCR is used to amplify segments of human DNA containing a common SNP. Allelic nucleotides in the amplified product are then typed by a calorimetric implementation of the oligonucleotide ligation assay (OLA). The results of the combined assay, PCR/OLA, are read directly by a spectrophotometer; the absorbances are compiled and the genotypes are automatically determined. A panel of 20 markers has been developed for DNA typing and has been tested using a sample panel from the CEPH pedigrees (CEPH parents). The results of this typing, as well as the potential to apply this method to larger populations, are discussed. 62 refs., 2 figs., 4 tabs.

  11. Laser brackets debonding: Tm:YAP and ClarityTM SL self-ligating appliance system

    Science.gov (United States)

    Dostálová, Tatjana; Jelínková, Helena; Šulc, Jan; Koranda, Petr; Němec, Michal; Jelínek, Michal; Fibrich, Martin; Michalik, Pavel; Miyagi, Mitsunobu

    2010-02-01

    The study demonstrates the possibility of using Tm:YAP laser radiation for the removing ceramic brackets. The amount of enamel loss and residual resin on teeth has been evaluated. A diode-pumped Tm:YAP microchip laser generating at wavelength 1.9 μm was used for the debonding process. The transmission and absorption measurement of the basic elements - bracket, adhesive resin, and enamel was analyzed to explain the source of the heat and bracket debonding. Quantitative measurements are made for visualizing enamel surface before and after a self-ligating bonding technique. Temperature rise observation during the debonding procedure - from 0.5 to 2 W power - has improved the accuracy of assessment. The results were evaluated by CCD camera and scanning electron microscope. From the measurements it is possible to conclude that continuously running small diode pumped Tm:YAP microchip laser having output power 1W can remove the ceramic bracket without enamel iatrogenic damage.

  12. Effect of glutamine synthetase inhibition on brain and interorgan ammonia metabolism in bile duct ligated rats

    DEFF Research Database (Denmark)

    Fries, Andreas W; Dadsetan, Sherry; Keiding, Susanne;

    2014-01-01

    Ammonia has a key role in the development of hepatic encephalopathy (HE). In the brain, glutamine synthetase (GS) rapidly converts blood-borne ammonia into glutamine which in high concentrations may cause mitochondrial dysfunction and osmolytic brain edema. In astrocyte-neuron cocultures and brains...... of healthy rats, inhibition of GS by methionine sulfoximine (MSO) reduced glutamine synthesis and increased alanine synthesis. Here, we investigate effects of MSO on brain and interorgan ammonia metabolism in sham and bile duct ligated (BDL) rats. Concentrations of glutamine, glutamate, alanine......, and aspartate and incorporation of (15)NH4(+) into these amino acids in brain, liver, muscle, kidney, and plasma were similar in sham and BDL rats treated with saline. Methionine sulfoximine reduced glutamine concentrations in liver, kidney, and plasma but not in brain and muscle; MSO reduced incorporation...

  13. Hmb(off/on) as a switchable thiol protecting group for native chemical ligation.

    Science.gov (United States)

    Qi, Yun-Kun; Tang, Shan; Huang, Yi-Chao; Pan, Man; Zheng, Ji-Shen; Liu, Lei

    2016-05-01

    A new thiol protecting group Hmb(off/on) is described, which has a switchable activity that may be useful in the chemical synthesis of proteins. When placed on the side chain of Cys, Cys(Hmb(off)) is stable to trifluoroacetic acid (TFA) in the process of solid-phase peptide synthesis. When Cys(Hmb(off)) is treated with neutral aqueous buffers, it is cleanly converted to acid-labile Cys(Hmb(on)), which can later be fully deprotected by TFA to generate free Cys. The utility of Cys(Hmb(off/on)) is demonstrated by the chemical synthesis of an erythropoietin segment, EPO[Cys(98)-Arg(166)]-OH through native chemical ligation. PMID:27102373

  14. [Experimental results after acute and chronic ligation of bile duct (author's transl)].

    Science.gov (United States)

    Kirchner, R; Hartung, H; Trendelenburg, C

    1980-08-01

    The bile duct was ligated in 14 bastard dogs. Bilirubine, alcaline phosphatase, GOT, GPT, GLDH, and gamma GT were measured pre- and postoperatively. On the 8th postoperative day stenosis of the choledochus was eliminated using a patch plasty for dilatation in 7 dogs, whereas the occlusion remained in the other 7 dogs. Laboratory and histological results were characteristic for cholestasis 8 days after occlusion; these changes disappeared within 4 weeks after patch plastic surgery. In the controls these parameters normalized as well within 8 weeks, in spite of the persisting occlusion. These results show, that pathological changes after short term cholestasis are fully reversible; they demonstrate as well, that there are compensatory mechanisms operating in dogs with permanent occlusion of the bile duct.

  15. Proximity ligation in situ assay for monitoring the global DNA methylation in cells

    Directory of Open Access Journals (Sweden)

    Vallette François M

    2011-04-01

    Full Text Available Abstract Background DNA methylation has a central role in the epigenetic control of mammalian gene expression, and is required for X inactivation, genomics imprinting and silencing of retrotransposons and repetitive sequences. Thus, several technologies have been developed to measure the degree of DNA methylation. Results We here present the development of the detection of protein-protein interactions via the adaptation of the proximity ligation in situ technology to evaluate the DNA methylation status in cells since the quantification of Dnmt1/PCNA interaction in cells reflects the degree of DNA methylation. Conclusion This method being directly realizable on cells, it appears that it could suggest a wide range of applications in basic research and drug development. More particularly, this method is specially adapted for the investigations realized from a weak quantity of biologic materiel such as stem cells or primary cultured tumor cells for examples.

  16. Validation of multiplex ligation-dependent probe amplification for confirmation of array comparative genomic hybridization.

    Science.gov (United States)

    Jennings, Lawrence J; Yu, Min; Fitzpatrick, Carrie; Smith, Frederick A

    2011-09-01

    The American College of Medical Genetics recommends that each laboratory should confirm abnormal or ambiguous results detected by array comparative genomic hybridization (aCGH). At present, the gold standard method for aCGH confirmation is fluorescent in situ hybridization (FISH). However, FISH is not well suited for small tandem duplications or very small deletions that are detectable by oligonucleotide arrays. Therefore, we developed and validated multiplex ligation-dependent probe amplification (MLPA) for aCGH confirmation. The method performance validation showed linearity through the expected analytical measurement range (0.05 to 2 genome equivalents). The interassay normalized coefficient of variation averaged 3.7% across 12 control and target probes. This low imprecision allowed detection of 20% mosaicism with exceptional confidence (Pcomparision with reference populations. We have successfully incorporated aCGH confirmation using custom-designed MLPA into our normal workflow, and used it for confirmation of all abnormal or ambiguous results. PMID:21817904

  17. Demonstration of metabolic and cellular effects of portal vein ligation using multi-modal PET/MRI measurements in healthy rat liver.

    Directory of Open Access Journals (Sweden)

    András Fülöp

    Full Text Available OBJECTIVES: In the early recognition of portal vein ligation (PVL induced tumor progression, positron emission tomography and magnetic resonance imaging (PET/MRI could improve diagnostic accuracy of conventionally used methods. It is unknown how PVL affects metabolic patterns of tumor free hepatic tissues. The aim of this preliminary study is to evaluate the effect of PVL on glucose metabolism, using PET/MRI imaging in healthy rat liver. MATERIALS AND METHODS: Male Wistar rats (n=30 underwent PVL. 2-deoxy-2-(18Ffluoro-D-glucose (FDG PET/MRI imaging (nanoScan PET/MRI and morphological/histological examination were performed before (Day 0 and 1, 2, 3, and 7 days after PVL. Dynamic PET data were collected and the standardized uptake values (SUV for ligated and non-ligated liver lobes were calculated in relation to cardiac left ventricle (SUVVOI/SUVCLV and mean liver SUV (SUVVOI/SUVLiver. RESULTS: PVL induced atrophy of ligated lobes, while non-ligated liver tissue showed compensatory hypertrophy. Dynamic PET scan revealed altered FDG kinetics in both ligated and non-ligated liver lobes. SUVVOI/SUVCLV significantly increased in both groups of lobes, with a maximal value at the 2nd postoperative day and returned near to the baseline 7 days after the ligation. After PVL, ligated liver lobes showed significantly higher tracer uptake compared to the non-ligated lobes (significantly higher SUVVOI/SUVLiver values were observed at postoperative day 1, 2 and 3. The homogenous tracer biodistribution observed before PVL reappeared by 7th postoperative day. CONCLUSION: The observed alterations in FDG uptake dynamics should be taken into account during the assessment of PET data until the PVL induced atrophic and regenerative processes are completed.

  18. Intestinal absorption and postabsorptive metabolism of linoleic acid in rats with short-term bile duct ligation

    NARCIS (Netherlands)

    Minich, DM; Havinga, R; Stellaard, F; Vonk, RJ; Kuipers, F; Verkade, HJ

    2000-01-01

    We investigated in bile duct-ligated (BDL) and sham-operated control rats whether the frequent presence of essential fatty acid deficiency in cholestatic liver disease could be related to linoleic acid malabsorption, altered linoleic acid metabolism, or both. In plasma of BDL rats, the triene-to-tet

  19. Do intra-operative fluids influence the need for post-operative cardiotropic support after a PDA ligation?

    Institute of Scientific and Technical Information of China (English)

    Brigitte LEMYRE; Ling LIU; Gregory Paul MOORE; Sarah Linda LAWRENCE; Nicholas J. BARROWMAN

    2011-01-01

    Objective To investigate the effect of intra-operative intravenous fluids on post-operative hemodynamic stability. Methods We performed a retrospective cohort study of 98 preterm infants who underwent a patent ductus arteriosus (PDA) ligation in one N1CU between 2001 and 2007. The primary outcome was the need for cardiotropic support within 24 hrs of ligation. Results Twenty-seven infants (28%) required post-operative cardiotropic support. The amount of intra-operative fluids varied between 0 and 50.4 mL/kg (median; 10.2 mL/kg). No intra-operative fluid was recorded in 26 patients. Fluids were not associated with the need for post-operative cardiotropic support (P = 0. 10). Using a multivariate logistic regression model, age at ligation, weight at ligation and pre-operative FiO2 were significant predictors of post-operative cardiotropic support. Conclusions Intra-operative fluids do not appear to be associated with the need for post-operative cardiotropic support. A prospective cohort study may help identify modifiable risk factors and improve outcomes in this population.

  20. Proton NMR investigation of heme and surrounding proton in low-spin cyanide-ligated bacterial hemoglobin from Vitreoscilla

    Institute of Scientific and Technical Information of China (English)

    夏佑林; 吴季辉; 光寿红; 张海阳; 梁山; 施蕴渝

    2000-01-01

    1H NMR spectra of low-spin cyanide-ligated bacterial hemoglobin from Vitreoscilla (VtHb-CN) are reported. The assignments of the 1H NMR spectra of VtHb-CN have been made through MCOSY, NOESY, 1D TOE and SUPERWEFT experiments. Almost all resonance peaks of heme and ligated His85 are identified. The spin-lattice relaxation time T1’s and the variation relationships of chemical shifts of these peaks with temperature have been acquired, from which the distances between the measured protons and Fe3+, and the diamagnetic chemical shifts have been acquired, respectively. The ionization constants of pKa’s of ligated His85 are determined through pH titration of chemical shift, which is 4.95 for ligated His85 C2H proton. The lower pKa is attributed to the influence of the Fe3+ of carrying positive charge and the coordination of His85 and Fe3+ of heme.

  1. Size-dependent stability toward dissociation and ligand binding energies of phosphine-ligated gold cluster ions

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Grant E.; Priest, Thomas A.; Laskin, Julia

    2014-01-01

    The stability of sub-nanometer size gold clusters ligated with organic molecules is of paramount importance to the scalable synthesis of monodisperse size-selected metal clusters with highly tunable chemical and physical properties. For the first time, a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR-MS) equipped with surface induced dissociation (SID) has been employed to investigate the time and collision energy resolved fragmentation behavior of cationic doubly charged gold clusters containing 7-9 gold atoms and 6-7 triphenylphosphine (TPP) ligands prepared by reduction synthesis in solution. The TPP ligated gold clusters are demonstrated to fragment through three primary dissociation pathways: (1) Loss of a neutral TPP ligand from the precursor gold cluster, (2) asymmetric fission and (3) symmetric fission and charge separation of the gold core resulting in formation of complementary pairs of singly charged fragment ions. Threshold energies and activation entropies of these fragmentation pathways have been determined employing Rice-Ramsperger-Kassel-Marcus (RRKM) modeling of the experimental SID data. It is demonstrated that the doubly charged cluster ion containing eight gold atoms and six TPP ligands, (8,6)2+, exhibits exceptional stability compared to the other cationic gold clusters examined in this study due to its large ligand binding energy of 1.76 eV. Our findings demonstrate the dramatic effect of the size and extent of ligation on the gas-phase stability and preferred fragmentation pathways of small TPP-ligated gold clusters.

  2. A systematic analysis of DMTMM vs EDC/NHS for ligation of amines to hyaluronan in water.

    Science.gov (United States)

    D'Este, Matteo; Eglin, David; Alini, Mauro

    2014-08-01

    The activation of carboxyl groups with N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide (EDC/NHS) for amide formation is the standard method for amine ligation to hyaluronan (HA), and a very well established wide-ranging bioconjugation method. In this paper we compare 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) to EDC/NHS activation chemistry for HA ligation using an array of substrates including small, large and functional molecules. For all the substrates tested DMTMM yields were superior at parity of feed ratio. DMTMM chemistry resulted effective also in absence of pH control, which is essential for EDC/NHS conjugation. Overall our results demonstrate that DMTMM is more efficient than EDC/NHS for ligation of amines to HA and does not require accurate pH control or pH shift during the reaction to be effective. DMTMM-mediated ligation is a new promising chemical tool to synthesize HA derivatives for biomedical and pharmaceutical applications. PMID:24751270

  3. Prophylactic Role of Echinacea, Green Tea and Boswellia Extracts in Pyloric Ligation-Induced Gastric Ulcer in Rats

    Directory of Open Access Journals (Sweden)

    Souty M. Sharkawi

    2012-10-01

    Full Text Available Peptic ulcer is a common disorder of the stomach and duodenum. Herbs and medicinal plants are considered to be a potential source to combat various diseases including gastric ulcer. The present study was conducted to evaluate the gastro protective effects of Echinacea extract, Green tea extract and Boswellia extract on a pyloric ligation-induced gastric ulcer. Six groups of rats were intraperitoneally pre-treated with saline as normal group, saline as ulcer group, 20 mg/kg of ranitidine as positive group, Echinacea extract (25 mg/kg, I.P, Green tea extract (25 mg/kg, I.P and Boswellia extract (200 mg/kg, I.P for 15 consecutive days before pyloric ligation. Gastric acidity, ulcer index and histology were assessed. Gastric homogenates were determined for Malondialdehyde (MDA content, Glutathione (GSH content in addition to blood Superoxide Dismutase (SOD activity. Pyloric ligation elevated gastric acidity, ulcer index and malondialdehyde content, while glutathione content and superoxide dismutase activity were significantly decreased. Prior administration of extracts mitigated the injurious effects of pyloric ligation. Echinacea, Green tea and Boswellia extracts separately ameliorated all the altered biochemical parameters. These results were confirmed histologically. These data suggested that Green tea, Echinacea or Boswellia extract could have a protective role in gastric ulcer probably via regulation of oxidant/antioxidant balance.

  4. Heterolytic H2 activation on a carbene-ligated rhodathiaborane promoted by isonido-nido cage opening

    OpenAIRE

    Calvo, Beatriz; Macías, Ramón; Polo, Víctor; Artigas, Maria Jose; Lahoz, Fernando J.; Oro, Luis A.

    2013-01-01

    A new mechanism of H2 activation is reported to occur on a carbene-ligated rhodathiaborane that features metal-thiaborane bifunctional synergistic effects. The key is the creation of vacant coordination sites by an isonido-nido structural transformation leading to the heterolytic H-H bond splitting. © 2013 The Royal Society of Chemistry.

  5. Multiplex ligation-dependent probe amplification for the detection of chromosomal gains and losses in formalin-fixed tissue.

    NARCIS (Netherlands)

    Dijk, M.C.R.F. van; Rombout, P.D.M.; Sprenger, S.H.E.; Straatman, H.M.P.M.; Bernsen, M.R.; Ruiter, D.J.; Jeuken, J.W.M.

    2005-01-01

    Molecular analysis on formalin-fixed paraffin-embedded tissue is of increasing importance in diagnostic histopathology and tumor research. Multiplex ligation-dependent probe amplification (MLPA) is a technique that can be used for detection of copy number alterations of up to 45 different DNA sequen

  6. Endoscopic variceal ligation plus propranolol vs. transjugular intrahepatic portosystemic stent shunt : A long-term randomized trial

    NARCIS (Netherlands)

    Sauer, P; Hansmann, J; Richter, GM; Stremmel, W; Stiehl, A

    2002-01-01

    Background and Study Aims: After a first variceal bleeding episode in patients with cirrhosis of the liver, treatment with transjugular intrahepatic portosystemic stent shunt (TIPS) and endoscopic variceal ligation (EVL) plus propranolol were compared, with regard to prevention of variceal rebleedin

  7. Synthesis of histone proteins by CPE ligation using a recombinant peptide as the C-terminal building block.

    Science.gov (United States)

    Kawakami, Toru; Yoshikawa, Ryo; Fujiyoshi, Yuki; Mishima, Yuichi; Hojo, Hironobu; Tajima, Shoji; Suetake, Isao

    2015-11-01

    The post-translational modification of histones plays an important role in gene expression. We report herein on a method for synthesizing such modified histones by ligating chemically prepared N-terminal peptides and C-terminal recombinant peptide building blocks. Based on their chemical synthesis, core histones can be categorized as two types; histones H2A, H2B and H4 which contain no Cys residues, and histone H3 which contains a Cys residue(s) in the C-terminal region. A combination of native chemical ligation and desulphurization can be simply used to prepare histones without Cys residues. For the synthesis of histone H3, the endogenous Cys residue(s) must be selectively protected, while keeping the N-terminal Cys residue of the C-terminal building block that is introduced for purposes of chemical ligation unprotected. To this end, a phenacyl group was successfully utilized to protect endogenous Cys residue(s), and the recombinant peptide was ligated with a peptide containing a Cys-Pro ester (CPE) sequence as a thioester precursor. Using this approach it was possible to prepare all of the core histones H2A, H2B, H3 and H4 with any modifications. The resulting proteins could then be used to prepare a core histone library of proteins that have been post-translationally modified.

  8. MicroRNA expression analysis and Multiplex ligation-dependent probe amplification in metastatic and non-metastatic uveal melanoma

    DEFF Research Database (Denmark)

    Larsen, Ann-Cathrine; Holst, Line; Kaczkowski, Bogumil;

    2014-01-01

    Purpose: To determine the association of microRNA expression and chromosomal changes with metastasis and survival in uveal melanoma (UM). Methods: Thirty-six patients with UM were selected based on the metastatic status, and clinicopathological data were collected. Multiplex ligation-dependent pr...

  9. Two-way molecular ligation for efficient conversion of monomeric hepatitis B virus DNA constructs into tandem dimers.

    Science.gov (United States)

    Zong, Li; Qin, Yanli; Jia, Haodi; Zhou, Huailiang; Chen, Chaoyang; Qiao, Ke; Zhang, Jiming; Wang, Yongxiang; Li, Jisu; Tong, Shuping

    2016-07-01

    Replication of the 3.2-kb hepatitis B virus (HBV) genome is driven by the covalently closed circular (ccc) DNA in the nucleus, from which four classes of co-terminal RNAs are transcribed. Genome replication requires just the 3.5-kb pregenomic RNA, which is terminally redundant. Cloning the full-length HBV genome into a vector disrupts its continuity, thus preventing genome replication at the step of pregenomic RNA transcription. This can be overcome by converting the monomeric construct into a tandem dimer, yet the need to ligate two molecules of the HBV genome with vector DNA makes it inefficient and even unsuccessful. To overcome this problem we partially digested the monomeric construct with the unique restriction enzyme used for cloning, and dephosphorylated the linearized monomer before its ligation with another copy of the HBV genome. Alternatively, the monomer was linearized at another unique restriction site inside the HBV genome, followed by its dephosphorylation and ligation with another copy of the HBV genome linearized at the same site. These approaches of two-way molecular ligation greatly improved the efficiency of dimer formation with about 50% of the bacterial colonies screened harboring tandem dimers. PMID:27025357

  10. PERIPANCREATIC ARTERIAL LIGATION COMBINED WITH ARTERIAL INFUSION REGIONAL CHEMOTHERAPY FOR TREATING PATIENTS WITH ADVANCED PANCREATIC CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To find out a new treatment method for advanced pancreatic carcinoma. Methods Twenty-nine patients with advanced pancreatic carcinoma and liver metastases were randomly divided into 2 groups.Group A (n=11) underwent bilio-enterostomy and/or gastro-enterostomy combined with systemic chemotherapy after operation;Group B(n=18) underwent bilio-enterostomy and/or gastro-enterostomy combined with peripancreatic arterial ligation and arterial infusion regional chemotherapy.The alleviation of clinical symptom,the change of carcinoma volume by BUS and CT scan,survival period and serum CEA were observed in two groups. Results The symptoms were alleviated apparently in most cases in Group B;BUS and CT scan showed that the tumor volume decreased apparently in Group B;The response rate was 67.7% in Group B,and 18.2% in Group A,respectively(P<0.01);the mean survival period was (4.8±0.6) months in Group A,and (12.5±1.2) months in Group B,respectively(P<0.01),there was significant difference between the two groups.The decrease of serum CEA was 54% in Group A and 60% in Group B,but the difference was not significant(P>0.05). Conclusion Peripancreatic arterial ligation combined with arterial infusion regional chmotherapy is believed to be effective against both pancreatic carcinoma and liver metastases,and it can alleviate the clinical symptoms,postpone the growth speed of tumor,and prolong the survival period.

  11. The ligational behavior of an isatinic quinolyl hydrazone towards copper(II- ions

    Directory of Open Access Journals (Sweden)

    Mousa Marwa A

    2011-04-01

    Full Text Available Abstract Background The importance of the isatinic quinolyl hydrazones arises from incorporating the quinoline ring with the indole ring. Quinoline ring has therapeutic and biological activities whereas, the indole ring occurs in Jasmine flowers and Orange blossoms. As a ligand, the isatin moiety is potentially ambidentate and can coordinate the metal ions either through its lactam or lactim forms. In a previous study, the ligational behavior of a phenolic quinolyl hydrazone towards copper(II- ions has been studied. As continuation of our interest, the present study is planned to check the ligational behavior of an isatinic quinolyl hydrazone. Results New homo- and heteroleptic copper(II- complexes were obtained from the reaction of an isatinic quinolyl hydrazone (HL with several copper(II- salts viz. Clˉ, Brˉ, NO3ˉ, ClO4-, SO42- and AcO-. The obtained complexes have Oh, Td and D4h- symmetry and fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO42- anions. Depending on the type of the anion, the ligand coordinates the copper(II- ions either through its lactam (NO3ˉ and ClO4- or lactim (the others forms. Conclusion The effect of anion for the same metal ion is obvious from either the geometry of the isolated complexes (Oh, Td and D4h or the various modes of bonding. Also, the obtained complexes fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO42- anions in consistency with the donor ability of the anions. In case of copper(II- acetate, a unique homoleptic complex (5 was obtained in which the AcO- anion acts as a base enough to quantitatively deprotonate the hydrazone. The isatinic hydrazone uses its lactim form in most complexes.

  12. Dose-related effects of dexamethasone on liver damage due to bile duct ligation in rats

    Institute of Scientific and Technical Information of China (English)

    Halil Eken; Hayrettin Ozturk; Hulya Ozturk; Huseyin Buyukbayram

    2006-01-01

    AIM: To evaluate the effects of dexamethasone on liver damage in rats with bile duct ligation. METHODS: A total of 40 male Sprague-Dawley rats,weighing 165-205 g, were used in this study. Group 1 (sham-control, n = 10) rats underwent laparotomy alone and the bile duct was just dissected from the surrounding tissue. Group 2 rats (untreated, n = 10)were subjected to bile duct ligation (BDL) and no drug was applied. Group 3 rats (low-dose dexa, n = 10)received a daily dose of dexamethasone by orogastric tube for 14 d after BDL. Group 4 rats (high-dose dexa,n = 10) received a daily dose of dexamethasone by orogastric tube for 14 d after BDL. At the end of the twoweek period, biochemical and histological evaluations were processed.RESULTS: The mean serum bilirubin and liver enzyme levels significantly decreased, and superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSHPx) values were significantly increased in low-dose dexa and high-dose dexa groups when compared to the untreated group. The histopathological score was significantly less in the low-dose and high-dose dexa groups compared to the untreated rats. In the low-dose dexa group, moderate liver damage was seen, while mild liver damage was observed in the high-dose dexa group.CONCLUSION: Corticosteroids reduced liver damage produced by bile duct obstruction. However, the histopathological score was not significantly lower in the high-dose corticosteroid group as compared to the lowdose group. Thus, low-dose corticosteroid provides a significant reduction of liver damage without increased side effects, while high dose is associated not with lower fibrosis but with increased side effects.

  13. Sensitive detection of Aβ protofibrils by proximity ligation - relevance for Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Gustafsdottir Sigrun

    2010-10-01

    Full Text Available Abstract Background Protein aggregation plays important roles in several neurodegenerative disorders. For instance, insoluble aggregates of phosphorylated tau and of Aβ peptides are cornerstones in the pathology of Alzheimer's disease. Soluble protein aggregates are therefore potential diagnostic and prognostic biomarkers for their cognate disorders. Detection of the aggregated species requires sensitive tools that efficiently discriminate them from monomers of the same proteins. Here we have established a proximity ligation assay (PLA for specific and sensitive detection of Aβ protofibrils via simultaneous recognition of three identical determinants present in the aggregates. PLA is a versatile technology in which the requirement for multiple target recognitions is combined with the ability to translate signals from detected target molecules to amplifiable DNA strands, providing very high specificity and sensitivity. Results For specific detection of Aβ protofibrils we have used a monoclonal antibody, mAb158, selective for Aβ protofibrils in a modified PLA, where the same monoclonal antibody was used for the three classes of affinity reagents required in the assay. These reagents were used for detection of soluble Aβ aggregates in solid-phase reactions, allowing detection of just 0.1 pg/ml Aβ protofibrils, and with a dynamic range greater than six orders of magnitude. Compared to a sandwich ELISA setup of the same antibody the PLA increases the sensitivity of the Aβ protofibril detection by up to 25-fold. The assay was used to measure soluble Aβ aggregates in brain homogenates from mice transgenic for a human allele predisposing to Aβ aggregation. Conclusions The proximity ligation assay is a versatile analytical technology for proteins, which can provide highly sensitive and specific detection of Aβ aggregates - and by implication other protein aggregates of relevance in Alzheimer's disease and other neurodegenerative disorders.

  14. Ultrasound assisted great saphenous vein ligation and division: an office procedure

    Directory of Open Access Journals (Sweden)

    Stefano Ricci

    2014-10-01

    Full Text Available The aim of this proof of concept study is to describe an ultrasound (US assisted simplified surgical procedure for pre-terminal great saphenous vein (GSV high ligation/division avoiding groin dissection and tributary interruption, in an office setting, in association to varices phlebectomy and saphenous vein foam occlusion treatment. Inclusion criteria: primary GSV reflux due to terminal valve, vein diameter >6 mm. By ultrasonography in standing position, the point GSV passing over the adductor longus muscle (about 3 cm from the junction is identified. This E (easy point, relatively superficial, free from tributaries and other structures, allows an easy grasping and extraction of the GSV vein through a 3 mm stab incision provided an ultrasonography assistance. The vein is divided/ligated about 2 cm distal from the ostium, the distal stump is cannulated and foam is injected on the distal segment from the E-point incision in a retrograde fashion, varices are avulsed by phlebectomy. Twenty procedures in 18 patients (venous clinical severity score: mean 3.15 - GSV diameter: mean 7.34 were performed, all the cases without inconveniences, with a duration not exceeding 10 min in addition to the phlebectomy procedure time. No complications as hemorrhage, infection, nerve lesion, lymphatic leak or thrombosis have been registered. At one month the residual saphenous stump length was in average 2.16 cm with complete closure of GSV in all. Three patients have been controlled at 6 months showing GSV complete closure. The procedure described is a simple office US assisted method for GSV ligationdivision, leaving the 2 last cm of the saphenofemoral junction. It could be associated to most of the procedures in use with limited additional time and resources required.

  15. Intrahepatic Left to Right Portoportal Venous Collateral Vascular Formation in Patients Undergoing Right Portal Vein Ligation

    Energy Technology Data Exchange (ETDEWEB)

    Lienden, K. P. van, E-mail: k.p.vanlienden@amc.uva.nl [Academic Medical Center, University of Amsterdam, Department of Interventional Radiology (Netherlands); Hoekstra, L. T. [Academic Medical Center, University of Amsterdam, Department of Surgery (Netherlands); Bennink, R. J. [Academic Medical Center, University of Amsterdam, Department of Nuclear Medicine (Netherlands); Gulik, T. M. van [Academic Medical Center, University of Amsterdam, Department of Surgery (Netherlands)

    2013-12-15

    Purpose: We investigated intrahepatic vascular changes in patients undergoing right portal vein ligation (PVL) or portal vein embolization (PVE) in conjunction with the ensuing hypertrophic response and function of the left liver lobe. Methods: Between December 2008 and October 2011, 7 patients underwent right PVL and 14 patients PVE. Computed tomographic (CT) volumetry to assess future remnant liver (FRL) and functional hepatobiliary scintigraphy were performed in all patients before and 3 weeks after portal vein occlusion. In 18 patients an intraoperative portography was performed to assess perfusion through the occluded portal branches. Results: In all patients after initially successful PVL, reperfused portal veins were observed on CT scan 3 weeks after portal occlusion. This was confirmed in all cases during intraoperative portography. Intrahepatic portoportal collaterals were identified in all patients in the PVL group and in one patient in the PVE group. In all other PVE patients, complete occlusion of the embolized portal branches was observed on CT scan and on intraoperative portography. The median increase of FRL volume after PVE was 41.6 % (range 10-305 %), and after PVL was only 8.1 % (range 0-102 %) (p = 0.179). There were no differences in FRL function between both groups. Conclusion: Preoperative PVE and PVL are both methods to induce hypertrophy of the FRL in anticipation of major liver resection. Compared to PVE, PVL seems less efficient in inducing hypertrophy of the nonoccluded left lobe. This could be caused by the formation of intrahepatic portoportal neocollateral vessels, through which the ligated portal branches are reperfused within 3 weeks.

  16. Identification of zinc-ligated cysteine residues based on 13Calpha and 13Cbeta chemical shift data.

    Science.gov (United States)

    Kornhaber, Gregory J; Snyder, David; Moseley, Hunter N B; Montelione, Gaetano T

    2006-04-01

    Although a significant number of proteins include bound metals as part of their structure, the identification of amino acid residues coordinated to non-paramagnetic metals by NMR remains a challenge. Metal ligands can stabilize the native structure and/or play critical catalytic roles in the underlying biochemistry. An atom's chemical shift is exquisitely sensitive to its electronic environment. Chemical shift data can provide valuable insights into structural features, including metal ligation. In this study, we demonstrate that overlapped 13Cbeta chemical shift distributions of Zn-ligated and non-metal-ligated cysteine residues are largely resolved by the inclusion of the corresponding 13Calpha chemical shift information, together with secondary structural information. We demonstrate this with a bivariate distribution plot, and statistically with a multivariate analysis of variance (MANOVA) and hierarchical logistic regression analysis. Using 287 13Calpha/13Cbeta shift pairs from 79 proteins with known three-dimensional structures, including 86 13Calpha and 13Cbeta shifts for 43 Zn-ligated cysteine residues, along with corresponding oxidation state and secondary structure information, we have built a logistic regression model that distinguishes between oxidized cystines, reduced (non-metal ligated) cysteines, and Zn-ligated cysteines. Classifying cysteines/cystines with a statistical model incorporating all three phenomena resulted in a predictor of Zn ligation with a recall, precision and F-measure of 83.7%, and an accuracy of 95.1%. This model was applied in the analysis of Bacillus subtilis IscU, a protein involved in iron-sulfur cluster assembly. The model predicts that all three cysteines of IscU are metal ligands. We confirmed these results by (i) examining the effect of metal chelation on the NMR spectrum of IscU, and (ii) inductively coupled plasma mass spectrometry analysis. To gain further insight into the frequency of occurrence of non-cysteine Zn

  17. Alteration of P2X3 expression in dorsal root ganglia after sciatic nerve ligation

    Institute of Scientific and Technical Information of China (English)

    Guoxing Zhou; Lesi Xie; Qiben Wang; Qingping Yu; Xiaofu Liu; Qiumei Liu; Wei Peng; Zhicheng Zeng

    2007-01-01

    BACKGROUND: The expressions of P2X3 receptor in dorsal root ganglia (DRG) after different peripheral nerve injuries are diverse. It indicates the different roles of P2X3 in different models-caused neuropathologic pains.OBJECTIVE: To observe the expressions of P2X3 in corresponding DRG after sciatic nerve ligation in rats.DESIGN: Controlled observation experiment.SETTING: Department of Morphology, Hunan Traditional Chinese Medical College; Department of Human Anatomy and Neurobiology, Xiangya Medical College, Central South University.MATERIALS: Thirty-five healthy adult SD rats of clean grade an d either gender, weighing (200±20) g,were involved. According to the random digits table, the involved rats were randomized into 3 groups:normal group (n =5), sham-operated group (n =5) and experimental group (n =25). The experimental group were subdivided into 3, 7, 14, 21, 28 days groups according to different surviving time after operation, 5 rats at each time point. Polyclonal rabbit anti-P2X3 antibody (ABCAM company); biotinylated goat anti-rabbit IgG (Zhongshanjingqiao Biotechnical Co., Ltd., Beijing); Motic fluorescence microscope (Motic, Germany).METHODS: The experiments were carried out in the Department of Human Anatomy and Neurobiology,Xiangya Medical College, Central South University from June to December 2006. ① Rats of experimental group were created into models by ligation of right sciatic nerve according to the method of Seltzer et al. Left sciatic nerve was used as self-control. As for rats in the sham-operated group, ligation of sciatic nerve was omitted, but other procedures were the same as those in the experimental group. Rats of normal group were untouched. ② Rats of the normal group and sham-operated group survived for 14 days separately, and those of experimental group survived for corresponding time. After being deeply anesthetized by intraperitoneal injection of over-dose sodium pentobarbital, the rats of experimental group were transcardially

  18. Mineral commodity profiles: nitrogen

    Science.gov (United States)

    Kramer, Deborah A.

    2004-01-01

    Overview -- Nitrogen (N) is an essential element of life and a part of all animal and plant proteins. As a part of the DNA and RNA molecules, nitrogen is an essential constituent of each individual's genetic blueprint. As an essential element in the chlorophyll molecule, nitrogen is vital to a plant's ability to photosynthesize. Some crop plants, such as alfalfa, peas, peanuts, and soybeans, can convert atmospheric nitrogen into a usable form by a process referred to as 'fixation.' Most of the nitrogen that is available for crop production, however, comes from decomposing animal and plant waste or from commercially produced fertilizers. Commercial fertilizers contain nitrogen in the form of ammonium and/or nitrate or in a form that is quickly converted to the ammonium or nitrate form once the fertilizer is applied to the soil. Ammonia is generally the source of nitrogen in fertilizers. Anhydrous ammonia is commercially produced by reacting nitrogen with hydrogen under high temperatures and pressures. The source of nitrogen is the atmosphere, which is almost 80 percent nitrogen. Hydrogen is derived from a variety of raw materials, which include water, and crude oil, coal, and natural gas hydrocarbons. Nitrogen-based fertilizers are produced from ammonia feedstocks through a variety of chemical processes. Small quantities of nitrates are produced from mineral resources principally in Chile. In 2002, anhydrous ammonia and other nitrogen materials were produced in more than 70 countries. Global ammonia production was 108 million metric tons (Mt) of contained nitrogen. With 28 percent of this total, China was the largest producer of ammonia. Asia contributed 46 percent of total world ammonia production, and countries of the former U.S.S.R. represented 13 percent. North America also produced 13 percent of the total; Western Europe, 9 percent; the Middle East, 7 percent; Central America and South America, 5 percent; Eastern Europe, 3 percent; and Africa and Oceania

  19. Commercial Nitrogen Fertilizer Purchased

    Data.gov (United States)

    U.S. Environmental Protection Agency — Amounts of fertilizer nitrogen (N) purchased by states in individual years 2003, 2005, 2007, 2009 and 2011, and the % change in average amounts purchased per year...

  20. Nitrogen oxide formation from chemically-bound nitrogen during the combustion of fossil fuels. [Extended Zeldovich reactions

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, R.E.

    1976-06-01

    One of the many problems associated with the firing of fossil fuels is the impact on the ambient levels of nitrogen oxides. Since the use of coals, oils and coal-derived fuels is expected to triple by 1985, it is urgent that the formation of nitrogen oxides from molecular nitrogen and organo-nitrogen species be fully characterized so that emission abatement strategies can be formulated. The thermal fixation of atmospheric nitrogen and the free radical reactions of nitrogenous species are the sources of NO/sub x/. The fixation reactions can be described by the extended Zeldovich mechanism, and techniques such as staged combustion and flue gas recirculation have been employed to reduce combustion temperatures and, hence, thermally formed NO. These techniques have had little effect, however, on the conversion of chemically-bound nitrogen to NO/sub x/. The fate of chemically-bound nitrogen depends upon such factors as the nitrogen content of the fuel and the equivalence ratio and upon the physical processes governing combustion. Research is proposed to establish the kinetic processes involved in the conversion of fuel nitrogen to NO and N/sub 2/ in environments characteristic of fossil fuel combustion and to identify those conditions which favor the reduction of NO to N/sub 2/.

  1. Surgical Ligation for Patent Ductus Arteriosus in Extremely Premature Infants: Strategy to Reduce their Risk of Neurodevelopmental Impairment.

    Science.gov (United States)

    Ito, Satoko; Matsuda, Tadashi; Usuda, Haruo; Watanabe, Shimpei; Kitanishi, Ryuta; Hanita, Takushi; Watanabe, Tatsuya; Adachi, Osamu

    2016-01-01

    Surgical ligation for patent ductus arteriosus (PDA) in extremely low birth weight infants (ELBWIs) has been shown a possible association with neurodevelopmental impairment (NDI) because of its invasiveness. However, we have undergone surgical ligation for ELBWIs immediately after cyclooxygenase inhibitor failed to close a hemodynamically significant PDA (hsPDA) to maintain proper systemic circulation. We aimed to determine the effect of surgical ligation for hsPDA on NDI in ELBWIs. In enrolled 71 ELBWIs, the clinical parameters, including the developmental quotient (DQ), were collected and compared among three groups that were divided by closure mode: spontaneous closure (n = 11), cyclooxygenase inhibitor therapy (n = 37) and surgical ligation (n = 23). No significant differences in DQ at the age of 36 months among the three groups were found: Median (interquartile range): 92.0 (31.0), 89.0 (22.0) and 92.0 (24.5), respectively. In a comparison between groups of DQ < 70 (n = 15) and DQ ≥ 70 (n = 56), a significant difference was found in the parameters related to prematurity (p < 0.05 for each): gestational age [23.9 (1.70) vs. 25.4 (2.50) weeks], birth weight [595 (183) vs. 714 (192) g], Apgar score < 5 (1 min) (67% vs. 36%), and laser photocoagulation for retinopathy of prematurity (73% vs. 43%), but there was no significant association with hsPDA. Therefore, we propose that surgical ligation for hsPDA in ELBWIs should be immediately carried out for preventing future neurodevelopmental deterioration if the cyclooxygenase inhibitor failed to close hsPDA. PMID:27558322

  2. Comparison of frictional resistance between self-ligating and conventional brackets tied with elastomeric and metal ligature in orthodontic archwires

    Directory of Open Access Journals (Sweden)

    Vanessa Vieira Leite

    2014-06-01

    Full Text Available OBJECTIVE: To compare the frictional resistance between self-ligating and conventional brackets tied to different types of wire. MATERIAL AND METHODS : Abzil Kirium Capelozza (Pattern I and Easy Clip (Roth prescription incisor brackets were used. An elastomeric ligature or a ligating wire 0.10-in was used to ligate the wire to the Abzil bracket. Three types of orthodontic archwire alloys were assessed: 0.016-in NiTi wire, 0.016 x 0.021-in NiTi wire and 0.019 x 0.025-in steel wire. Ten observations were carried out for each bracket-archwire angulation combination. Brackets were mounted in a special appliance, positioned at 90 degrees in relation to the wire and tested in two angulations. Frictional test was performed in a Universal Testing Machine at 5 mm/min and 10 mm of displacement. The means (MPa were submitted to ANOVA and Tukey's test set at 5% of significance. The surfaces of wires and brackets were observed at SEM. RESULTS: Steel-tied brackets (16.48 ± 8.31 showed higher means of frictional resistance than elastomeric-tied brackets (4.29 ± 2.16 and self-ligating brackets (1.66 ± 1.57 (P 0.05. No statistical differences (P > 0.05 were found between zero (7.76 ± 8.46 and five-degree (7.19 ± 7.93 angulations. CONCLUSIONS: Friction was influenced not only by the type of bracket, but also by the ligating systems. Different morphological aspects were observed for the brackets and wires studied

  3. Epiregulin is critical for the acinar cell regeneration of the submandibular gland in a mouse duct ligation model.

    Science.gov (United States)

    Nagai, Koichi; Arai, Hideo; Okudera, Michisato; Yamamura, Takashi; Oki, Hidero; Komiyama, Kazuo

    2014-05-01

    Acinar cell regeneration from tubular structures has been reported to occur in duct-deligated salivary glands. However, the detailed process of acinar cell regeneration has not been clarified. We have developed a mouse duct ligation model to clarify the mechanisms underlying acinar cell regeneration, and we analyzed the epidermal growth factor receptor (EGFR) and epidermal growth factor (EGF) ligands using the model. We studied these ligands expressions in the course of acinar cell regeneration using immunohistochemistry and RT-PCR methods. In the duct-ligated portion of the submandibular gland (SMG) that underwent atrophy, newly formed acinar cells were observed arising from the tubular structures after the release of the duct obstruction. The constitutive expression of EGFR was observed by immunohistochemistry in both the duct-ligated and duct-deligated animals as well as in normal controls. The EGFR phosphorylation detected on the tubular structures after duct ligation paralleled the acinar cell regeneration. RT-PCR showed an increase in the epiregulin and heparin-binding EGF levels from day 0 to day 3 after the release of the duct obstruction. The EGF level was increased only after day 7. In vitro, cultured cells isolated from ligated SMGs proliferated and produced EGF ligands following the addition of epiregulin to the culture medium. These findings suggest that the tubular structures localized in an atrophic gland are the source of acinar cell regeneration of the salivary gland. The induction of EGF ligands, in particular epiregulin, may play an important role in acinar cell regeneration in this model.

  4. 腹腔镜电凝结扎术和开腹结扎术的疗效比较%Effect Comparison between Laparoscopic Electrocoagulation Ligation and Open Ligation

    Institute of Scientific and Technical Information of China (English)

    陈士花

    2013-01-01

    Objective:To observe the clinical effect and safety of laparoscopic electrocoagulation tubal ligation and open tubal ligation.Method:64 patients received tubal ligation in our hospital in 2011 were selected and divided into two groups according to different treatment methods.Two groups received laparoscopic electrocoagulation tubal ligation and open ligation respectively.And the surgical situation and follow-up result of two groups were analyzed.Result:The operation time,bleeding volume in operation,analgesics application after operation,postoperative fever and length of stay of the patients received laparoscopic electrocoagulation ligation were better than those of the patients received open ligation(P<0.05).After following up for (14.8±6.9)months,incision pain,incision infection,the incidence rate of chronic pelvic pain and failure rate of operation of the patients receiving laparoscopic electrocoagulation ligation were lower evidently,there were statistically significant differences(P<0.05).Conclusion:Laparoscopic electrocoagulation tubal ligation has the advantages of small surgical trauma,short recovery time,less complications and evident improvement of sterilisation effect,which is promoted and applied to family planning operation.%目的:探讨腹腔镜电凝输卵管结扎术与开腹输卵管结扎术的临床效果与安全性。方法:选取本院2011年行输卵管结扎绝育手术的患者64例,根据治疗方法的不同随机平均分为两组,分别行腹腔镜输卵管电凝与开腹输卵管结扎手术,统计两组患者的手术情况与随访结果。结果:腹腔镜组患者手术时间、术中出血量、术后镇痛药物使用、术后发热以及住院时间均优于开腹组(P<0.05),术后随访(14.8±6.9)个月,腹腔镜组的切口疼痛、切口感染、慢性盆腔痛发生率、手术失败率均明显低于开腹组,比较差异均有统计学意义(P<0.05)。结论:腹腔镜输卵管

  5. Delayed Treatment with Sodium Hydrosulfide Improves Regional Blood Flow and Alleviates Cecal Ligation and Puncture (CLP)-Induced Septic Shock.

    Science.gov (United States)

    Ahmad, Akbar; Druzhyna, Nadiya; Szabo, Csaba

    2016-08-01

    Cecal ligation and puncture (CLP)-induced sepsis is a serious medical condition, caused by a severe systemic infection resulting in a systemic inflammatory response. Recent studies have suggested the therapeutic potential of donors of hydrogen sulfide (H2S), a novel endogenous gasotransmitter and biological mediator in various diseases. The aim of the present study was to assess the effect of H2S supplementation in sepsis, with special reference to its effect on the modulation of regional blood flow. We infused sodium hydrosulfide (NaHS), a compound that produces H2S in aqueous solution (1, 3, or 10 mg/kg/h, for 1 h at each dose level) in control rats or rats 24 h after CLP, and measured blood flow using fluorescent microspheres. In normal control animals, NaHS induced a characteristic redistribution of blood flow, and reduced cardiac, hepatic, and renal blood flow in a dose-dependent fashion. In contrast, in rats subjected to CLP, cardiac, hepatic, and renal blood flow was significantly reduced; infusion of NaHS (1 mg/kg/h and 3 mg/kg/h) significantly increased organ blood flow. In other words, the effect of H2S on regional blood flow is dependent on the status of the animals (i.e., a decrease in blood flow in normal controls, but an increase in blood flow in CLP). We have also evaluated the effect of delayed treatment with NaHS on organ dysfunction and the inflammatory response by treating the animals with NaHS (3 mg/kg) intraperitoneally (i.p.) at 24 h after the start of the CLP procedure; plasma levels of various cytokines and tissue indicators of inflammatory cell infiltration and oxidative stress were measured 6 h later. After 24 h of CLP, glomerular function was significantly impaired, as evidenced by markedly increased (over 4-fold over baseline) blood urea nitrogen and creatinine levels; this increase was also significantly reduced by treatment with NaHS. NaHS also attenuated the CLP-induced increases in malondialdehyde levels (an index of

  6. Delayed Treatment with Sodium Hydrosulfide Improves Regional Blood Flow and Alleviates Cecal Ligation and Puncture (CLP)-Induced Septic Shock.

    Science.gov (United States)

    Ahmad, Akbar; Druzhyna, Nadiya; Szabo, Csaba

    2016-08-01

    Cecal ligation and puncture (CLP)-induced sepsis is a serious medical condition, caused by a severe systemic infection resulting in a systemic inflammatory response. Recent studies have suggested the therapeutic potential of donors of hydrogen sulfide (H2S), a novel endogenous gasotransmitter and biological mediator in various diseases. The aim of the present study was to assess the effect of H2S supplementation in sepsis, with special reference to its effect on the modulation of regional blood flow. We infused sodium hydrosulfide (NaHS), a compound that produces H2S in aqueous solution (1, 3, or 10 mg/kg/h, for 1 h at each dose level) in control rats or rats 24 h after CLP, and measured blood flow using fluorescent microspheres. In normal control animals, NaHS induced a characteristic redistribution of blood flow, and reduced cardiac, hepatic, and renal blood flow in a dose-dependent fashion. In contrast, in rats subjected to CLP, cardiac, hepatic, and renal blood flow was significantly reduced; infusion of NaHS (1 mg/kg/h and 3 mg/kg/h) significantly increased organ blood flow. In other words, the effect of H2S on regional blood flow is dependent on the status of the animals (i.e., a decrease in blood flow in normal controls, but an increase in blood flow in CLP). We have also evaluated the effect of delayed treatment with NaHS on organ dysfunction and the inflammatory response by treating the animals with NaHS (3 mg/kg) intraperitoneally (i.p.) at 24 h after the start of the CLP procedure; plasma levels of various cytokines and tissue indicators of inflammatory cell infiltration and oxidative stress were measured 6 h later. After 24 h of CLP, glomerular function was significantly impaired, as evidenced by markedly increased (over 4-fold over baseline) blood urea nitrogen and creatinine levels; this increase was also significantly reduced by treatment with NaHS. NaHS also attenuated the CLP-induced increases in malondialdehyde levels (an index of

  7. Nitrogen Inputs via Nitrogen Fixation in Northern Plants and Soils

    Science.gov (United States)

    Thorp, N. R.; Wieder, R. K.; Vile, M. A.

    2015-12-01

    Dominated by cold and often acidic water logged environments, mineralization of organic matter is slow in the majority of northern ecosystems. Measures of extractable ammonium and nitrate are generally low and can be undetectable in peat pore waters. Despite this apparent nitrogen limitation, many of these environments produce deep deposits of soil organic matter. Biological nitrogen fixation carried out by autotrophic and heterotrophic diazotrophs associated with cryptograms provides the majority of known nitrogen inputs in these northern ecosystems. Nitrogen fixation was assessed in a variety of northern soils within rhizospheres of dominant plant communities. We investigated the availability of this newly fixed nitrogen to the vascular plant community in nitrogen limited northern plant communities. We tracked nitrogen flow from 15N2 gas fixed in Sphagnum mosses into tissues of two native vascular plant species, boreal cranberry (Vaccinium oxycoccus) and black spruce (Picea mariana). 15N-labeled Sphagnum microcosms were grown within variable mesh size exclusion/inclusion fabrics in a nitrogen addition experiment in situ in order to investigate the role of mycorrhizal fungi in the uptake of newly fixed nitrogen. Up to 24% of daily fixed 15N label was transferred to vascular plant tissues during 2 months. Nitrogen addition resulted in decreased N2 fixation rates; however, with higher nitrogen availability there was a higher rate of 15N label uptake into the vascular plants, likely the result of increased production of dissolved organic nitrogen. Reliance on mycorrhizal networks for nitrogen acquisition was indicated by nitrogen isotope fractionation patterns. Moreover, N2 fixation activities in mosses were stimulated when vascular plants were grown in moss microcosms versus "moss only" treatments. Results indicate that bog vascular plants may derive considerable nitrogen from atmospheric N2 biologically fixed within Sphagnum mosses. This work demonstrates that

  8. Failed surgical ligation of the proximal left subclavian artery during hybrid thoracic endovascular aortic repair successfully managed by percutaneous plug or coil occlusion: a report of 3 cases

    Directory of Open Access Journals (Sweden)

    Vaninbroukx Johan

    2011-04-01

    Full Text Available Abstract Open surgical rerouting and proximal ligation of one or more supra-aortic vessels prior to endovascular stent-graft placement has become an alternative to major open thoracic surgery in the treatment of complex thoracic aortic disease. Complications owing to failed surgical ligation of the left subclavian artery are rare. In this report, 3 cases of failed ligation are presented. Diagnosis was made by CT-scan and treatment was performed by transcatheter coil and plug embolization, avoiding redo neck surgery.

  9. Is Previous Tubal Ligation a Risk Factor for Hysterectomy because of Abnormal Uterine Bleeding?

    Directory of Open Access Journals (Sweden)

    Sanam Moradan

    2012-07-01

    Full Text Available Objectives: Post tubal ligation syndrome (PTLS is a term used to describe a variety of post tubal ligation side effects or symptoms. These include increased menstrual bleeding and hysterectomy. Whether or not post tubal syndrome is a real entity, it has been a subject of controversy in the medical literature for decades. Numerous studies have reported conflicting conclusions about these symptoms. In this study the incidence of hysterectomy for bleeding disorders among sterilized women was compared with the incidence of hysterectomy for bleeding disorders among non-sterilized female population of the same age.Methods: This study was carried out on 160 women, 38-52 years, who underwent hysterectomy in Amir University Hospital, Semnan, Iran, from September 2008 to September 2011. After gathering of data from medical records, in this study, the incidence of hysterectomy for bleeding disorders among sterilized women was compared with the incidence of hysterectomy for bleeding disorders among nonsterilized female population for the same age.Results: The mean age of the study group was 44/4±5/7 and the mean age of the control group was 45/2±5/3, (p=0.424.The mean parity of the study group was 3/8±1/8 and the mean parity of the control group was 3/5±1/4, (p=0.220. So, in regard to age and parity, two groups were matched. Hysterectomies were performed for 160 cases and abnormal uterine bleeding was the cause of hysterectomy in 67 cases. Among 67 cases, 19 cases (37.3% had previous tubal sterilization + hysterectomy (study group and 48 cases (44% were not undergoing tubal sterilization but had hysterectomy for abnormal bleeding causes (control group. Statistical analyses showed that there were not significant differences between two groups, (RR=0.85; 95% CI: 0.56-1.28; p=0.418.Conclusion: The result of this study showed that previous tubal sterilization is not a risk factor for undergoing hysterectomy because of abnormal uterine bleeding.

  10. Constructing recombinant replication-defective adenoviral vectors that express glucose transporter-1 through in vitro ligation

    Institute of Scientific and Technical Information of China (English)

    Fangcheng Li; Junliang Li; Ranyi Liu; Xinke Xu; Kaichang Yuan; Zhonghua Wu

    2008-01-01

    BACKGROUND: We constructed a homologous recombination bacterial method based on the pAdEasy system, a widely used system, for generating recombinant adenoviral vectors that express glucose transporter-1 (GLUT1) in rats.OBJECTIVE: This study was designed to investigate the feasibility of generating recombinant replication-defective adenoviral vectors that express GLUT1 in rats by in vitro ligation based on the Adeno-XTM system. DESIGN: An in vitro cell-based experiment. SETTING: This study was performed at the Linbaixin Medical Research Center of the Second Hospital Affiliated to Sun Yat-sen University and Central Laboratory for Prevention and Treatment of Tumor, Sun Yat-sen University between January and August 2004. MATERIALS: Male, adult, Sprague Dawley rats were used to extract total RNA from brain tissue. E. coli DH5?and human embryonic kidney 293 cells (HEK293 cells) used in the present study were cryo-preserved by the Second Hospital Affiliated to Sun Yat-sen University. Rabbit anti-rat GLUT1 polyclonal antibody (Chemicon, U.S.A.) and primers (Shanghai Boya Bioengineering Co., Ltd) were also used. METHODS: E1/E3-deleted replication-defective adenoviral vectors were used. Using in vitro ligation, the target gene was first sub-cloned into a shuttle vector plasmid to obtain the fragment containing target gene expression cassettes by enzyme digestion. Subsequently, the fragment was co-transformed with linearized adenoviral backbone vector into the E. coli strain. The recombinant adenoviral plasmid was transfected into HEK293 cells to assembly recombinant adenoviral vectors with replication capabilities. The procedure was repeated several times for recombinant adenoviral vectors amplification. MAIN OUTCOME MEASURES: Efficiency of recombinant adenoviral vectors to express the target gene was measured by gene and protein expression through polymerase chain reaction and Western Blot assays, respectively.RESULTS: Results demonstrated that recombinant adenoviral

  11. Carbon and nitrogen isotopic signatures and nitrogen profile to identify adulteration in organic fertilizers.

    Science.gov (United States)

    Verenitch, Sergei; Mazumder, Asit

    2012-08-29

    Recently it has been shown that stable isotopes of nitrogen can be used to discriminate between organic and synthetic fertilizers, but the robustness of the approach is questionable. This work developed a comprehensive method that is far more robust in identifying an adulteration of organic nitrogen fertilizers. Organic fertilizers of various types (manures, composts, blood meal, bone meal, fish meal, products of poultry and plant productions, molasses and seaweed based, and others) available on the North American market were analyzed to reveal the most sensitive criteria as well as their quantitative ranges, which can be used in their authentication. Organic nitrogen fertilizers of known origins with a wide δ(15)N range between -0.55 and 28.85‰ (n = 1258) were characterized for C and N content, δ(13)C, δ(15)N, viscosity, pH, and nitrogen profile (urea, ammonia, organic N, water insoluble N, and NO3). A statistically significant data set of characterized unique organic nitrogen fertilizers (n = 335) of various known origins has been assembled. Deliberately adulterated samples of different types of organic fertilizers mixed with synthetic fertilizers at a wide range of proportions have been used to develop the quantitative critical characteristics of organic fertilizers as the key indicators of their adulteration. Statistical analysis based on the discriminant functions of the quantitative critical characteristics of organic nitrogen fertilizers from 14 different source materials revealed a very high average rate of correct classification. The developed methodology has been successfully used as a source identification tool for numerous commercial nitrogen fertilizers available on the North American market.

  12. NITROGEN IN SUPERALLOYS

    Institute of Scientific and Technical Information of China (English)

    A. Mitchell

    2005-01-01

    Nitrogen has a significant effect on superalloy mechanical properties, almost without exception in a negative sense. All of the alloys contain strong nitride formers (Ti, V, Nb, Hf, Ta) and will,because of the nitride-former concentration, produce nitride precipitates not only during solidification but also when the alloy is fully liquid and significantly superheated. In this review we present an examination of the problems involved in removing nitrogen from the alloys and also of the mechanisms by which nitrides influence mechanical behaviour. It is concluded that one of the most effective means of control of the nitrogen content lies in the choice of raw materials for the alloy make-up, but that the subsequent nitride formation can be minimised by correct choice of process routes in VIM, ESR, VAR and EBCHM.

  13. Forest fuel reduces the nitrogen load - calculations of nitrogen flows

    International Nuclear Information System (INIS)

    Nitrogen deposition in Sweden has increased strongly during recent decades, particularly in southern Sweden. Nitrogen appears to be largely accumulated in biomass and in the soil. It is therefore desirable to check the accumulation of nitrogen in the forest. The most suitable way of doing this is to remove more nitrogen-rich biomass from the forest, i.e., increase the removal of felling residues from final fellings and cleanings. An ecological condition for intensive removal of fuel is that the ashes are returned. The critical load for nitrogen, CL(N), indicates the level of nitrogen deposition that the forest can withstand without leading to ecological changes. Today, nitrogen deposition is higher than the CL(N) in almost all of Sweden. CL(N) is calculated in such a manner that nitrogen deposition should largely be balanced by nitrogen losses through harvesting during a forest rotation. The value of CL(N) thus largely depends on how much nitrogen is removed with the harvested biomass. When both stems and felling residues are harvested, the CL(N) is about three times higher than in conventional forestry. The increase is directly related to the amount of nitrogen in the removed biofuel. Use of biofuel also causes a certain amount of nitrogen emissions. From the environmental viewpoint there is no difference between the sources of the nitrogen compounds. An analysis of the entire fuel chain shows that, compared with the amount of nitrogen removed from the forest with the fuel, about 5 % will be emitted as nitrogen oxides or ammonia during combustion, and a further ca 5 % during handling and transports. A net amount of about 90 % of biomass nitrogen is removed from the system and becomes inert nitrogen (N2). 60 refs, 3 figs, 4 tabs, 11 appendices

  14. Indigenous nitrogen in the Moon: Constraints from coupled nitrogen-noble gas analyses of mare basalts

    Science.gov (United States)

    Füri, Evelyn; Barry, Peter H.; Taylor, Lawrence A.; Marty, Bernard

    2015-12-01

    Nitrogen and noble gas (Ne-Ar) abundances and isotope ratios, determined by step-wise CO2 laser-extraction, static-mass spectrometry analysis, are reported for bulk fragments and mineral separates of ten lunar mare basalts (10020, 10057, 12008, 14053, 15555, 70255, 71557, 71576, 74255, 74275), one highland breccia (14321), and one ferroan anorthosite (15414). The mare basalt sub-samples 10057,183 and 71576,12 contain a large amount of solar noble gases, whereas neon and argon in all other samples are purely cosmogenic, as shown by their 21Ne/22Ne ratios of ≈0.85 and 36Ar/38Ar ratios of ≈0.65. The solar-gas-free basalts contain a two-component mixture of cosmogenic 15N and indigenous nitrogen (Earth's primordial mantle or an enstatite chondrite-like impactor. While the lowest δ15 N values allow for nitrogen trapped in the Moon's interior to be inherited from the proto-Earth and/or the impactor, the more 15N-enriched compositions require that carbonaceous chondrites provided nitrogen to the lunar magma ocean prior to the solidification of the crust. Since nitrogen can efficiently be incorporated into mafic minerals (olivine, pyroxene) under oxygen fugacities close to or below the iron-wustite buffer (Li et al., 2013), the mare basalt source region is likely characterized by a high nitrogen storage capacity. In contrast, anorthosite 15414 shows no traces of indigenous nitrogen, suggesting that nitrogen was not efficiently incorporated into the lunar crust during magma ocean differentiation.

  15. Nanoscale Nitrogen Doping in Silicon by Self-Assembled Monolayers

    Science.gov (United States)

    Guan, Bin; Siampour, Hamidreza; Fan, Zhao; Wang, Shun; Kong, Xiang Yang; Mesli, Abdelmadjid; Zhang, Jian; Dan, Yaping

    2015-07-01

    This Report presents a nitrogen-doping method by chemically forming self-assembled monolayers on silicon. Van der Pauw technique, secondary-ion mass spectroscopy and low temperature Hall effect measurements are employed to characterize the nitrogen dopants. The experimental data show that the diffusion coefficient of nitrogen dopants is 3.66 × 10-15 cm2 s-1, 2 orders magnitude lower than that of phosphorus dopants in silicon. It is found that less than 1% of nitrogen dopants exhibit electrical activity. The analysis of Hall effect data at low temperatures indicates that the donor energy level for nitrogen dopants is located at 189 meV below the conduction band, consistent with the literature value.

  16. Nitrogen Availability Of Nitriding Atmosphere In Controlled Gas Nitriding Processes

    Directory of Open Access Journals (Sweden)

    Michalski J.

    2015-06-01

    Full Text Available Parameters which characterize the nitriding atmosphere in the gas nitriding process of steel are: the nitriding potential KN, ammonia dissociation rate α and nitrogen availabilitymN2. The article discusses the possibilities of utilization of the nitriding atmosphere’s nitrogen availability in the design of gas nitriding processes of alloyed steels in atmospheres derived from raw ammonia, raw ammonia diluted with pre-dissociated ammonia, with nitrogen, as well as with both nitrogen and pre-dissociated ammonia. The nitriding processes were accomplished in four series. The parameters selected in the particular processes were: process temperature (T, time (t, value of nitriding potential (KN, corresponding to known dissociation rate of the ammonia which dissociates during the nitriding process (α. Variable parameters were: nitrogen availability (mN2, composition of the ingoing atmosphere and flow rate of the ingoing atmosphere (FIn.

  17. 焦化蜡油中碱性氮化合物的ESI FT-ICR MS表征及其催化裂化反应特性%CHARACTERIZATION OF BASIC NITROGEN COMPOUNDS IN COKER GAS OIL BY ESI FT-ICR MS AND THEIR CATALYTIC CRACKING PERFORMANCE

    Institute of Scientific and Technical Information of China (English)

    陈小博; 沈本贤; 孙金鹏; 山红红

    2013-01-01

    利用盐酸-乙醇溶液对焦化蜡油(CGO)中的碱性氮化合物进行了萃取分离,采用电喷雾-傅里叶变换离子回旋共振质谱仪(ESI FT-ICR MS)对CGO及其盐酸抽提物中的碱性氮化合物进行了表征,并在小型提升管催化裂化实验装置上,考察了碱性氮化合物的催化裂化反应特性.结果表明:CGO中的碱性氮化合物以N1类化合物为主,主要是带烷基或环烷基侧链的喹啉类和苯并喹啉类衍生物;在催化裂化条件下,萃取出的碱性氮化合物仍具有一定的催化裂化性能,但转化率较低,主要发生烷基侧链、环烷基侧链以及联苯桥键的断裂反应,较高含量的碱性氮化合物和多环芳烃是导致其转化率低、产物分布差的关键因素.%The basic nitrogen compounds were extracted by hydrochloric acid and alcohol from CGO.Then the types and structures of basic nitrogen species in CGO and its hydrochloric extract were characterized by Electrospray Ionization (ESI) Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS),and the catalytic cracking performance of the basic nitrogen compounds was studied.The data indicate that N1 type basic nitrogen compounds are dominant in CGO and these species are mainly derivatives of quinoline and benzoquinoline with alkyl and cycloalkyl chains.Under the conditions of FCC,the basic nitrogen compounds extracted from CGO still have certain catalytic cracking ability;however,the conversion is relatively low.The bond-breakages of alkyl side-chains,cycloalkyl side-chains and biphenyl bridge are the main reaction.High content of basic nitrogen compounds and polycyclic aromatic hydrocarbons are the key factors that lead to lower conversion and poorer products distribution.

  18. 'Clickable' 2,5-diketopiperazines as scaffolds for ligation of biomolecules: their use in Aβ inhibitor assembly.

    Science.gov (United States)

    Dufour, E; Moni, L; Bonnat, L; Chierici, S; Garcia, J

    2014-07-21

    The synthesis of 1,3,6-trisubstituted-2,5-diketopiperazine scaffolds bearing up to three 'clickable' sites for further oxime bond or alkyne-azide cycloaddition ligations is described. The orthogonally Boc/Alloc protected DKP precursors prepared from L-lysine residues and an aminohexyl arm are efficiently prepared on a gram scale by sequentially using Fukuyama-Mitsunobu alkylation, dipeptide coupling and diketopiperazine ring formation as key steps. These scaffolds, with their glyoxylyl, aminooxy, alkynyl or azido functions, are "ready-to-use" platforms for biomolecular assembly. Their potentiality in this field was proved through the chemoselective ligation of Aβ-binding motifs, the KLVFFA peptide and the curcumin molecule. The inhibitory effect of these conjugates on Aβ amyloid fibril formation is reported using thioflavin T fluorescence assays and AFM observation.

  19. Shear bond strength of self-ligating orthodontic brackets on different types of porcelain crowns

    Directory of Open Access Journals (Sweden)

    Karamdeep Singh Ahluwalia

    2013-01-01

    Full Text Available Aim: The aim of this study is to compare shear bond strength (SBS and adhesive remnant index (ARI of self-ligating orthodontic brackets bonded to different porcelain crowns. Materials and Methods: Three groups of different types of porcelain crowns, each containing 12 crowns were fabricated by the same technician and allocated to one of the study groups as follows: Group I - IPS porcelain crowns (Ivoclar Vivadent AG, Schaan, Liechtenstein, Group II - Porcelain fused to zirconia crowns (Zirkonzahn GmbH, Gais, Italy, Noritake Co., Tokyo, Japan and Group III - Conventional porcelain fused to metal crowns (Ceramco3, Densply, PA, USA. The orthodontic brackets were bonded to these crowns using hydrofluoric acid (HFA + silane etching protocol. After bonding, the SBS of the brackets were tested with a universal testing machine under standard test conditions. Results: Statistical evaluation using analysis of variance showed a significant difference between the groups (P 0.05. Chi-square comparison revealed no significant difference in ARI scores between groups (P > 0.05. Conclusions: When HFA + silane etching protocol were used, IPS crowns showed the greatest SBS of orthodontic brackets. The ARI score was non-significant. Therefore, if there is a need to place crowns over teeth then these crowns can be used for restoration of teeth before orthodontic treatment.

  20. Endoscopic band ligation with a water-jet scope for the treatment of colonic diverticular hemorrhage.

    Science.gov (United States)

    Ishii, Naoki; Itoh, Toshiyuki; Uemura, Masayo; Maruyama, Masataka; Horiki, Noriyuki; Setoyama, Takeshi; Matsuda, Michitaka; Suzuki, Shoko; Iizuka, Yusuke; Fukuda, Katsuyuki; Fujita, Yoshiyuki

    2010-07-01

    Although lower gastrointestinal bleeding generally has a less severe course and stops spontaneously in most cases without therapeutic intervention, some patients require endoscopic, surgical, or angiographic treatment depending on the nature of the bleeding. We applied endoscopic band ligation (EBL) with a water-jet scope to bleeding colonic diverticula and evaluated the efficacy and safety of EBL retrospectively. Five consecutive patients were diagnosed as having colonic diverticular hemorrhage, and were treated with EBL at St Luke's International Hospital in Tokyo from June 2009 to August 2009. Comorbid diseases, usage of anti-platelet agents, hemoglobin level on admission, procedural time, complications such as perforation and abscess formation, and rebleeding after EBL were retrospectively evaluated. In all cases, EBL achieved successful immediate hemostasis without any procedural complications. In four of five cases, bleeding colonic diverticula were everted after EBL. The mean length of hospital stay after EBL was 5 days (range 4-8 days). No patient exhibited clinical evidence of further bleeding during the mean follow-up period of 3 months (range 2-4 months), and no further intervention was needed after EBL. EBL with a water-jet scope is considered to be a safe and effective endoscopic treatment for colonic diverticular hemorrhage. PMID:20642616

  1. Combining modular ligation and supramolecular self-assembly for the construction of star-shaped macromolecules.

    Science.gov (United States)

    Altintas, Ozcan; Muller, Thierry; Lejeune, Elise; Plietzsch, Oliver; Bräse, Stefan; Barner-Kowollik, Christopher

    2012-06-14

    A well-defined random copolymer of styrene (S) and chloromethylstyrene (CMS) featuring lateral chlorine moieties with an alkyne terminal group is prepared (P(S-co-CMS), M(n) = 5500 Da, PDI = 1.13). The chloromethyl groups are converted into Hamilton wedge (HW) entities (P(S-co-HWS), M(n) = 6200 Da, PDI = 1.13). The P(S-co-HWS) polymer is subsequently ligated with tetrakis(4-azidophenyl)methane to give HW-functional star-shaped macromolecules (P(S-co-HWS))(4), M(n) = 25,100 Da, PDI = 1.08). Supramolecular star-shaped copolymers are then prepared via self-assembly between the HW-functionalized four-arm star-shaped macromolecules (P(S-co-HW))(4) and cyanuric acid (CA) end-functionalized PS (PS-CA, M(n) = 3700 Da, PDI = 1.04), CA end-functionalized poly(methyl methacrylate) (PMMA-CA, M(n) = 8500 Da, PDI = 1.13) and CA end-functionalized polyethylene glycol (PEG-CA, M(n) = 1700 Da, PDI = 1.05). The self-assembly is monitored by (1)H NMR spectroscopy and light scattering analyses.

  2. Orthodontic Bracket Manufacturing Tolerances and Dimensional Differences between Select Self-Ligating Brackets

    Science.gov (United States)

    Major, Thomas W.; Carey, Jason P.; Nobes, David S.; Major, Paul W.

    2010-01-01

    In all manufacturing processes there are tolerances; however, orthodontic bracket manufacturers seldom state the slot dimensional tolerances. This experiment develops a novel method of analyzing slot profile dimensions using photographs of the slot. Five points are selected along each wall, and lines are fitted to define a trapezoidal slot shape. This investigation measures slot height at the slot's top and bottom, angles between walls, slot taper, and the linearity of each wall. Slot dimensions for 30 upper right central incisor self-ligating stainless steel brackets from three manufacturers were evaluated. Speed brackets have a slot height 2% smaller than the nominal 0.559 mm size and have a slightly convergent taper. In-Ovation brackets have a divergent taper at an average angle of 1.47 degrees. In-Ovation is closest to the nominal value of slot height at the slot base and has the smallest manufacturing tolerances. Damon Q brackets are the most rectangular in shape, with nearly 90-degree corners between the slot bottom and walls. Damon slot height is on average 3% oversized. PMID:20981299

  3. Temporal differential proteomes of Clostridium difficile in the pig ileal-ligated loop model.

    Directory of Open Access Journals (Sweden)

    Tavan Janvilisri

    Full Text Available The impact of Clostridium difficile infection (CDI on healthcare is becoming increasingly recognized as it represents a major cause of nosocomial diarrhea. A rising number of CDI cases and outbreaks have been reported worldwide. Here, we developed the pig ileal-ligated loop model for semi-quantitative analysis comparing temporal differential proteomes in C. difficile following in vivo incubation with in vitro growth using isobaric tags for relative and absolute quantification (iTRAQ. Proteins retrieved from the in vitro cultures and the loop contents after 4, 8, and 12 h in vivo incubation were subjected to in-solution digestion, iTRAQ labeling, two-dimensional liquid chromatography/tandem mass spectrometry and statistical analyses. From a total of 1152 distinct proteins identified in this study, 705 proteins were available for quantitative measures at all time points in both biological and technical replicates; 109 proteins were found to be differentially expressed. With analysis of clusters of orthologous group and protein-protein network interactions, we identified the proteins that might play roles in adaptive responses to the host environment, hence enhancing pathogenicity during CDI. This report represents the quantitative proteomic analysis of C. difficile that demonstrates time-dependent protein expression changes under conditions that mimic in vivo infection and identifies potential candidates for diagnostic or therapeutic measures.

  4. Heme oxygenase-1 overexpression increases liver injury after bile duct ligation in rats

    Institute of Scientific and Technical Information of China (English)

    Matthias Froh; Ronald G Thurman; Lars Conzelmann; Peter Walbrun; Susanne Netter; Reiner Wiest; Michael D Wheeler; Mark Lehnert; Takehiko Uesugi; Jurgen Scholmerich

    2007-01-01

    AIM: To investigate the effects of heme oxygenase-1(HO-1) against oxidant-induced injury caused by bile duct ligation (BDL).METHODS: Either cobalt protoporphyrin (CoPP), a HO-1 inducer, or saline were injected intraperitoneally in male SD-rats. Three days later, BDL or sham-operations were performed. Rats were sacrificed 3 wk after BDL and livers were harvested for histology. Fibrosis was evaluated by sirius red staining and image analysis.Alpha-smooth muscular actin, which indicates activation of stellate cells, was detected by immunohistochemical staining, and cytokine and collagen- Ⅰα (Col- Ⅰα) mRNA expression was detected using RNase protection assays.RESULTS: Serum alanine transaminase increased 8-fold above normal levels one day after BDL. Surprisingly,enzyme release was not reduced in rats receiving CoPP.Liver fibrosis was evaluated 3 wk after BDL and the sirius red-positive area was found to be increased to about 7.8%. However, in CoPP pretreated rats sirius redpositive areas were increased to about 11.7% after BDL.Collagen- Ⅰα and TGF-β mRNA increased significantly by BDL. Again, this effect was increased by HO-1overexpression.CONCLUSION: Hepatic fibrosis due to BDL is not reduced by the HO-1 inducer CoPP. In contrast, HO-1overexpression increases liver injury in rats under conditions of experimental chronic cholestasis.

  5. Hydrogen sulfide ameliorates cardiovascular dysfunction induced by cecal ligation and puncture in rats.

    Science.gov (United States)

    Abdelrahman, R S; El-Awady, M S; Nader, M A; Ammar, E M

    2015-10-01

    Hydrogen sulfide (H2S) is an endogenously produced gaseous messenger that participates in regulation of cardiovascular functions. This study evaluates the possible protective effect of H2S in cardiovascular dysfunction induced by cecal ligation and puncture (CLP) in rats. After 24 h of induction of CLP, heart rate (HR), mortality, cardiac and inflammation biomarkers (creatine kinase-MB (CK-MB) isozyme, cardiac troponin I (cTnI), C-reactive protein (CRP), and lactate dehydrogenase (LDH)), in vitro vascular reactivity, histopathological examination, and oxidative biomarkers (malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD)) were determined. CLP induced elevations in HR, mortality, serum CK-MB, cTnI, CRP, and LDH, in addition to impaired aortic contraction to potassium chloride and phenylephrine and relaxation to acetylcholine without affecting sodium nitroprusside responses. Moreover, CLP increased cardiac and aortic MDA and decreased SOD, without affecting GSH and caused a marked subserosal and interstitial inflammation in endocardium. Sodium hydrosulfide, but not the irreversible inhibitor of H2S synthesis dl-propargyl glycine, protected against CLP-induced changes in HR, mortality, cardiac and inflammatory biomarkers, oxidative stress, and myocardium histopathological changes without affecting vascular dysfunction. Our results confirm that H2S can attenuate CLP-induced cardiac, but not vascular, dysfunction possibly through its anti-inflammatory and antioxidant effects.

  6. Studies on different iron source absorption by in situ ligated intestinal loops of broilers.

    Science.gov (United States)

    Jia, Y F; Jiang, M M; Sun, J; Shi, R B; Liu, D S

    2015-02-01

    The objective of this study was to investigate the iron source absorption in the small intestine of broiler. In situ ligated intestinal loops of 70 birds were poured into one of seven solutions, including inorganic iron (FeSO4, Fe2(SO4)3), organic Fe glycine chelate (Fe-Gly(II), Fe-Gly(III)), the mixtures (FeSO4 with glycine (Fe+Gly(II)), Fe2(SO4)3 with glycine (Fe+Gly(III)), and no Fe source (control). The total volume of 3-mL solution (containing 1 mg of elemental Fe) was injected into intestinal loops, and then 120-min incubation was performed. Compared with inorganic iron groups, in which higher FeSO4 absorption than Fe2(SO4)3 was observed, supplementation with organic Fe glycine chelate significantly increased the Fe concentration in the duodenum and jejunum (P small intestine. Those results indicated that the absorption of organic Fe glycine chelate was more effective than that of inorganic Fe, and the orders of iron absorption in the small intestine were: Fe-Gly(II), Fe-Gly(III) > FeSO4, Fe+Gly(II) > Fe2(SO4)3, Fe+Gly(III). Additionally, the simple mixture of inorganic iron and glycine could not increase Fe absorption, and the duodenum was the main site of Fe absorption in the intestines of broilers and the ileum absorbed iron rarely.

  7. Synemin: Molecular Features and the Use of Proximity Ligation Assay to Study Its Interactions.

    Science.gov (United States)

    Paul, Madhumita; Skalli, Omar

    2016-01-01

    Synemin has three splice variants (α, β, and L) with identical head and rod domains but with tail domains of varying size. α- and β-Synemin are larger than most intermediate filament proteins (1565 and 1253 amino acids, respectively) but L-synemin is shorter (339 amino acids). Synemin isoforms do not self-assemble into filaments but can copolymerize with vimentin and desmin. Synemin is present in all muscle cell types, in a few neural cell types, and in various other nonepithelial cell types. Synemin expression is regulated, sometimes in an isoform-specific manner, during development of the nervous system, in brain and breast cancer cells and during injuries to the brain and liver. Mice-lacking synemin develop a myopathic phenotype, possibly due to synemin role in linking desmin filaments to costameres and sarcomeres. Synemin may play this role through its demonstrated binding to costameric and sarcolemmal proteins, such as α-actinin, vinculin, and members of the dystroglycan complex. In astrocytoma cells, synemin regulates proliferation by interacting with PP2A to modulate Akt phosphorylation status. Methods to identify synemin binding partners are central to understand the roles of this protein in diverse cell types. Here, we describe how to use proximal ligation assays (PLA) for this purpose. PLA complement biochemical methods such as immunoprecipitation by relying on the use of antibodies conjugated to oligonucleotide probes to visualize by fluorescence microscopy protein-protein interactions in cells and tissues.

  8. Thrombus-in-Transit Entrapped in a Partially Ligated Left Atrial Appendage

    Directory of Open Access Journals (Sweden)

    Farideh Roshanali

    2015-10-01

    Full Text Available A 54-year-old man referred to our center with Barlow’s disease and severe mitral regurgitation. He had atrial fibrillation (AF rhythm, with a mildly enlarged left atrium (LA. Transesophageal echocardiography (TEE showed no clot in the LA and LA appendage; there was only mild spontaneous echo contrast in the LA appendage. The patient underwent mitral valve repair and the Maze operation, during which the LA appendage was ligated with the double suture technique. He was discharged from the hospital in good condition and in sinus rhythm. He was recommended Warfarin and PT control.One month later, he returned with the complaint of vision loss twice in the left eye each time for a few seconds. The AF rhythm had returned.TEE demonstrated a fresh and mobile thrombus entrapped in the LA appendage with a small portion in the LA (Figures 1 and 2. Laboratory tests showed therapeutic international normalized ratio (INR. The patient refused re- operation.  Plavix was added to his medication, and he was discharged.

  9. Efficient Synthesis of Peptide and Protein Functionalized Pyrrole-Imidazole Polyamides Using Native Chemical Ligation.

    Science.gov (United States)

    Janssen, Brian M G; van Ommeren, Sven P F I; Merkx, Maarten

    2015-06-04

    The advancement of DNA-based bionanotechnology requires efficient strategies to functionalize DNA nanostructures in a specific manner with other biomolecules, most importantly peptides and proteins. Common DNA-functionalization methods rely on laborious and covalent conjugation between DNA and proteins or peptides. Pyrrole-imidazole (Py-Im) polyamides, based on natural minor groove DNA-binding small molecules, can bind to DNA in a sequence specific fashion. In this study, we explore the use of Py-Im polyamides for addressing proteins and peptides to DNA in a sequence specific and non-covalent manner. A generic synthetic approach based on native chemical ligation was established that allows efficient conjugation of both peptides and recombinant proteins to Py-Im polyamides. The effect of Py-Im polyamide conjugation on DNA binding was investigated by Surface Plasmon Resonance (SPR). Although the synthesis of different protein-Py-Im-polyamide conjugates was successful, attenuation of DNA affinity was observed, in particular for the protein-Py-Im-polyamide conjugates. The practical use of protein-Py-Im-polyamide conjugates for addressing DNA structures in an orthogonal but non-covalent manner, therefore, remains to be established.

  10. Efficient Synthesis of Peptide and Protein Functionalized Pyrrole-Imidazole Polyamides Using Native Chemical Ligation

    Directory of Open Access Journals (Sweden)

    Brian M. G. Janssen

    2015-06-01

    Full Text Available The advancement of DNA-based bionanotechnology requires efficient strategies to functionalize DNA nanostructures in a specific manner with other biomolecules, most importantly peptides and proteins. Common DNA-functionalization methods rely on laborious and covalent conjugation between DNA and proteins or peptides. Pyrrole-imidazole (Py–Im polyamides, based on natural minor groove DNA-binding small molecules, can bind to DNA in a sequence specific fashion. In this study, we explore the use of Py–Im polyamides for addressing proteins and peptides to DNA in a sequence specific and non-covalent manner. A generic synthetic approach based on native chemical ligation was established that allows efficient conjugation of both peptides and recombinant proteins to Py–Im polyamides. The effect of Py–Im polyamide conjugation on DNA binding was investigated by Surface Plasmon Resonance (SPR. Although the synthesis of different protein-Py–Im-polyamide conjugates was successful, attenuation of DNA affinity was observed, in particular for the protein-Py–Im-polyamide conjugates. The practical use of protein-Py–Im-polyamide conjugates for addressing DNA structures in an orthogonal but non-covalent manner, therefore, remains to be established.

  11. Chemical Ligation and Isotope Labeling to Locate Dynamic Effects during Catalysis by Dihydrofolate Reductase.

    Science.gov (United States)

    Luk, Louis Y P; Ruiz-Pernía, J Javier; Adesina, Aduragbemi S; Loveridge, E Joel; Tuñón, Iñaki; Moliner, Vincent; Allemann, Rudolf K

    2015-07-27

    Chemical ligation has been used to alter motions in specific regions of dihydrofolate reductase from E. coli and to investigate the effects of localized motional changes on enzyme catalysis. Two isotopic hybrids were prepared; one with the mobile N-terminal segment containing heavy isotopes ((2) H, (13) C, (15) N) and the remainder of the protein with natural isotopic abundance, and the other one with only the C-terminal segment isotopically labeled. Kinetic investigations indicated that isotopic substitution of the N-terminal segment affected only a physical step of catalysis, whereas the enzyme chemistry was affected by protein motions from the C-terminal segment. QM/MM studies support the idea that dynamic effects on catalysis mostly originate from the C-terminal segment. The use of isotope hybrids provides insights into the microscopic mechanism of dynamic coupling, which is difficult to obtain with other studies, and helps define the dynamic networks of intramolecular interactions central to enzyme catalysis.

  12. ProteinSeq: high-performance proteomic analyses by proximity ligation and next generation sequencing.

    Directory of Open Access Journals (Sweden)

    Spyros Darmanis

    Full Text Available Despite intense interest, methods that provide enhanced sensitivity and specificity in parallel measurements of candidate protein biomarkers in numerous samples have been lacking. We present herein a multiplex proximity ligation assay with readout via realtime PCR or DNA sequencing (ProteinSeq. We demonstrate improved sensitivity over conventional sandwich assays for simultaneous analysis of sets of 35 proteins in 5 µl of blood plasma. Importantly, we observe a minimal tendency to increased background with multiplexing, compared to a sandwich assay, suggesting that higher levels of multiplexing are possible. We used ProteinSeq to analyze proteins in plasma samples from cardiovascular disease (CVD patient cohorts and matched controls. Three proteins, namely P-selectin, Cystatin-B and Kallikrein-6, were identified as putative diagnostic biomarkers for CVD. The latter two have not been previously reported in the literature and their potential roles must be validated in larger patient cohorts. We conclude that ProteinSeq is promising for screening large numbers of proteins and samples while the technology can provide a much-needed platform for validation of diagnostic markers in biobank samples and in clinical use.

  13. Two-dimensional resonance Raman spectroscopy of oxygen- and water-ligated myoglobins

    Science.gov (United States)

    Molesky, Brian P.; Guo, Zhenkun; Cheshire, Thomas P.; Moran, Andrew M.

    2016-07-01

    Two-dimensional resonance Raman (2DRR) spectroscopy has recently been developed as a tool for studies of structural heterogeneity and photochemical dynamics in condensed phases. In this paper, 2DRR spectroscopy is used to investigate line broadening mechanisms of both oxygen- and water-ligated myoglobins. General signatures of anharmonicity and inhomogeneous line broadening are first established with model calculations to facilitate signal interpretation. It is shown that the present quasi-degenerate version of 2DRR spectroscopy is insensitive to anharmonicity, because signal generation is allowed for harmonic modes. Rather, the key information to be gained from 2DRR spectroscopy pertains to the line broadening mechanisms, which are fairly obvious by inspection of the data. 2DRR signals acquired for both heme protein systems reveal significant heterogeneity in the vibrational modes local to the heme's propionic acid side chains. These side chains are known to interact with solvent, because they protrude from the hydrophobic pocket that encloses the heme. Molecular dynamics simulations suggest that the heterogeneity detected in our 2DRR experiments reflects fluctuations in the geometries of the side chains. Knowledge of such thermal motions will be useful for understanding protein function (e.g., ligand binding) because the side chains are an effective "gateway" for the exchange of thermal energy between the heme and solvent.

  14. Generation of functional CLL-specific cord blood CTL using CD40-ligated CLL APC.

    Directory of Open Access Journals (Sweden)

    William K Decker

    Full Text Available Though remissions have been observed following allo-HSCT for the treatment of CLL, many CLL patients are ineligible for transplant due to the lack of HLA-compatible donors. The use of umbilical cord blood (UCB permits transplantation of many patients who lack HLA-compatible donors due to reduced requirements for stringent HLA matching between graft and recipient; however, disease relapse remains a concern with this modality. The generation of CLL-specific CTL from UCB T-cells, primed and expanded against the leukemic clone, might enhance the GVL effect and improve outcomes with UCB transplantation. Here we report the generation of functional, CLL-specific CTL using CD40-ligated CLL cells to prime partially-HLA matched UCB T-cells. Functionality and specificity were demonstrated by immune synapse assay, IFN-γ ELISpot, multi-parametric intracellular cytokine flow cytometry, and (51Cr release assay. The use of patient-specific, non-CLL controls demonstrated the generation of both alloantigen and CLL-specific responses. Subsequently, we developed a clinically-applicable procedure permitting separation of alloreactive CTL from leukemia-specific CTL. Leukemia-specific CTL were able to mediate in vivo killing of CLL in humanized mice without concurrent or subsequent development of xenoGVHD. Our results demonstrate that generation of CLL-specific effectors from UCB is feasible and practical, and the results support further exploration of this strategy as a treatment modality for CLL.

  15. Therapeutic effects of endoscopic variceal ligation combined with partial splenic embolization for portal hypertension

    Institute of Scientific and Technical Information of China (English)

    Rui-Yun Xu; Bo Liu; Nan Lin

    2004-01-01

    AIM: To evaluate the feasibility of a new strategy of endoscopic variceal ligation combined with partial splenic embolization (EVL-PSE) for patients with cirrhosis and portal hypertension.METHODS: From May 1999 to May 2002, 41 cases with cirrhosis and portal hypertension underwent EVL-PSE.Hemodynamics of the main portal vein (MPV), the left gastric vein (LGV) and azygos vein, including maximum velocity,flow rate and vein diameter, were assessed by Doppler ultrasonography.RESULTS: One case died from pulmonary artery embolism.One case complicated with splenic abscess was successfully managed by laparotomy. The esophageal varices and hypersplenism were well controlled after EVL-PSE in other patients. After EVL-PSE, the flow rate and velocity of MPV was significantly reduced (P<0.05), as well as the flow rate of the LGV and azygos vein. During the follow-up, no recurrent bleeding was found.CONCLUSION: Being more convenient and less invasive,EVL-PSE is hopeful to be a proper intervention strategy for portal hypertensive patients with impaired hepatic function or those intolerant to shunting or devascularization surgery.

  16. Esophageal varices before and after endoscopic variceal ligation: evaluation using helical CT

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, T.; Namba, R.; Matsuoka, T.; Tabuchi, K.; Yamamoto, K.; Uesugi, Y.; Matsui, R.; Sueyoshi, K.; Narabayashi, I. [Dept. of Radiology, Osaka Medical College (Japan)

    1999-10-01

    The purpose of this study was to demonstrate the utility of helical CT in assessing the therapeutic effects of endoscopic variceal ligation (EVL). Twenty-four patients with esophageal varices were examined. Helical scanning was initiated 60 s after intravenous injection (Iopamidol 300 mgI/ml, total 120 ml, 3 ml/s) was started. Esophageal varices were clearly depicted as high-density areas. Multiplanar reformation and 3D images demonstrated collateral circulation three-dimensionally. After EVL, mucosal high-density areas had diminished markedly, but collateral veins around the esophagus, and gastro- and/or spleno-renal shunts, were unchanged in all patients. Of 21 patients with collateral circulation, esophageal varices recurred endoscopically in 6 patients within 12 months. In 3 patients without collateral circulation, esophageal varices did not recur within 12 months. From these findings, we conclude that helical CT is a useful method for assessing the therapeutic effects of EVL. (orig.) With 3 figs., 1 tab., 14 refs.

  17. GENOMIC PROFILING BY MULTIPLEX LIGATION - DEPENDENT PROBE AMPLIFICATION IN CHRONIC LYMPHOCYTIC LEUKEMIA PATIENTS

    Directory of Open Access Journals (Sweden)

    Georgiana-Emilia Grigore

    2013-11-01

    Full Text Available The clinical management of severe pathological conditions, such as B-cell chronic lymphocytic leukemia (B-CLL, is subject to continuous optimization and re-evaluation. Patients may fully benefit from rapid, standardized laboratory tools designed to facilitate their early stratification according to disease risk, stage and prognosis. Such technologies may also aid the clinician in selecting the therapeutic option with the greatest chances of success. The presence of specific genetic abnormalities are frequently associated with the clinical outcome of oncologic patients in general, and B-CLL patients in particular. In the current study, a group of 58 B-CLL patients were evaluated for the detection of gene copy number alterations (deletions or duplication/ amplifications within 45 distinct genetic targets, by means of a novel molecular methodology, Multiplex Ligation - Dependent Probe Amplification (MLPA. Simple or complex genetic defects were identified in 67% of cases, and the most common aberrations observed were: deletion of the short arm of chromosome 13 in 33% of cases, deletion of the long arm of chromosome 11 in 16% of cases, trisomy 12 in 16% of cases, and deletion of the short arm of chromosome 17 in 7% of cases. The main conclusion of the study presented here points towards MLPA as a potential key step of clinical management protocols in B-CLL, providing that it will be fully standardised for routine diagnosis.

  18. Direct Copper(III) Formation from O2 and Copper(I) with Histamine Ligation.

    Science.gov (United States)

    Gary, J Brannon; Citek, Cooper; Brown, Timothy A; Zare, Richard N; Wasinger, Erik C; Stack, T Daniel P

    2016-08-10

    Histamine chelation of copper(I) by a terminal histidine residue in copper hydroxylating enzymes activates dioxygen to form unknown oxidants, generally assumed as copper(II) species. The direct formation of copper(III)-containing products from the oxygenation of histamine-ligated copper(I) complexes is demonstrated here, indicating that copper(III) is a viable oxidation state in such products from both kinetic and thermodynamic perspectives. At low temperatures, both trinuclear Cu(II)2Cu(III)O2 and dinuclear Cu(III)2O2 predominate, with the distribution dependent on the histamine ligand structure and oxygenation conditions. Kinetics studies suggest the bifurcation point to these two products is an unobserved peroxide-level dimer intermediate. The hydrogen atom reactivity difference between the trinuclear and binuclear complexes at parity of histamine ligand is striking. This behavior is best attributed to the accessibility of the bridging oxide ligands to exogenous substrates rather than a difference in oxidizing abilities of the clusters. PMID:27467215

  19. Cecal ligation and puncture followed by MRSA pneumonia increases mortality in mice and blunts production of local and systemic cytokines

    OpenAIRE

    Jung, Enjae; Perrone, Erin E.; Liang, Zhe; Elise R Breed; Dominguez, Jessica A.; Clark, Andrew T.; Fox, Amy C.; Dunne, W. Michael; Burd, Eileen M.; Farris, Alton B.; Richard S Hotchkiss; Coopersmith, Craig M.

    2012-01-01

    Mortality in the ICU frequently results from the synergistic effect of two temporally-distinct infections. This study examined the pathophysiology of a new model of intraabdominal sepsis followed by methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. Mice underwent cecal ligation and puncture (CLP) or sham laparotomy followed three days later by an intratracheal injection of MRSA or saline. Both CLP/saline and sham/MRSA mice had 100% survival while animals with CLP followed by MRSA ...

  20. Comparative study of friction between metallic and conventional interactive self-ligating brackets in different alignment conditions

    Science.gov (United States)

    Jakob, Sérgio Ricardo; Matheus, Davison; Jimenez-Pellegrin, Maria Cristina; Turssi, Cecília Pedroso; do Amaral, Flávia Lucisano Botelho

    2014-01-01

    Objective The aim of this study was to compare the friction between three bracket models: conventional stainless steel (Ovation, Dentsply GAC), self-ligating ceramic (In-Ovation, Denstply GAC) and self-ligating stainless steel brackets (In-Ovation R, Dentsply GAC). Methods Five brackets were used for each model. They were bonded to an aluminum prototype that allowed the simulation of four misalignment situations (n = 10). Three of these situations occurred at the initial phase (in which a 0.016-in nickel-titanium wire was used): 1. horizontal; 2. vertical; and 3. simultaneous horizontal/vertical. One of the situations occurred at the final treatment phase: 4. no misalignment (in which a 0.019 x 0.025-inch stainless steel rectangular wire was used). The wires slipped through the brackets and friction was measured by a Universal Testing Machine. Results Analysis of variance followed by Tukey's Test for multiple comparisons (α = 0.05) were applied to assess the results. Significant interaction (p bracket produced the highest friction. The two self-ligating models resulted in lower and similar values, except for the horizontal situation, in which In-Ovation C® showed lower friction, which was similar to the In-Ovation R® metallic model. For the no misalignment situation, the same results were observed. Conclusion The self-ligating system was superior to the conventional one due to producing less friction. With regard to the material used for manufacturing the brackets, the In-Ovation C® ceramic model showed less friction than the metallic ones. PMID:25162570

  1. Effect of passive self-ligating bracket placement on the posterior teeth on reduction of frictional force in sliding mechanics

    OpenAIRE

    Kim, Kyu-Ry; Baek, Seung-Hak

    2016-01-01

    Objective The purpose of this study was to investigate the static (SFF) and kinetic frictional forces (KFF) in sliding mechanics of hybrid bracket systems that involve placing a conventional bracket (CB) or active self-ligating bracket (ASLB) on the maxillary anterior teeth (MXAT) and a passive SLB (PSLB) on the maxillary posterior teeth (MXPT). Methods The samples consisted of two thoroughbred types (group 1, anterior-CB + posterior-CB; group 2, anterior-ASLB + posterior-ASLB) and four hybri...

  2. Analysis of lamb lung development with tracheal ligation in left posterolateral diaphragmatic hernia in cases and controls

    OpenAIRE

    Mahmoud Ashrafi; Masoud Jamshidi; Mahdi Fareed; Mohmmad Hosein Sanei

    2006-01-01

    BACKGROUND: When we perform surgery in utero, lungs have an appropriate time to decrease magnitude of hypoplasia, with surgery in uterus. METHODS: Six time-dated single-fetus ewes were selected to induce diaphragmatic hernia. Fetal lambs were divided proportionally into 2 groups, namely group 1, diaphragmatic hernia and tracheal ligation (TL group), and group 2, diaphragmatic hernia only (NL group). Morphologic assessments (weight, volume, bronchiolar branching) and histological tests (l...

  3. Bilateral spermatic cord en bloc ligation by laparoendoscopic single-site surgery: preliminary experience compared to conventional laparoscopy

    OpenAIRE

    Micali, Salvatore; Ghaith, Ahmed; Martorana, Eugenio; Zordani, Alessio; Territo, Angelo; Bianchi, Giampaolo

    2014-01-01

    Background Laparo Endoscopic Single-site Surgery (LESS) represents an evolution of minimally invasive surgery and aims to improve cosmetic outcome and reduce surgical trauma and complications associated with traditional laparoscopy. This study was performed to present our preliminary experience in bilateral spermatic cord ligation with the LESS technique and compare the results with the outcomes of conventional laparoscopic surgery. Methods Between June 2007 and May 2013, 24 patients were ref...

  4. A validated system for ligation-free USER™ -based assembly of expression vectors for mammalian cell engineering

    DEFF Research Database (Denmark)

    Lund, Anne Mathilde; Kildegaard, Helene Faustrup; Hansen, Bjarne Gram;

    The development in the field of mammalian cell factories require fast and high-throughput methods, this means a high need for simpler and more efficient cloning techniques. For optimization of protein expression by genetic engineering and for allowing metabolic engineering in mammalian cells, a new...... versatile expression vector system was developed. This vector system applies the ligation-free uracilexcision cloning technique to construct mammalian expression vectors of multiple parts and with maximum flexibility....

  5. Triplex Forming Oligonucleotides against Type α 1(I) Collagen attenuates Liver Fibrosis induced by Bile Duct ligation

    OpenAIRE

    Panakanti, Ravikiran; Pratap, Akshay; Yang, Ningning; JACKSON, JOHN S.; Mahato, Ram I.

    2010-01-01

    Liver fibrosis is a consequence of chronic liver disorders which lead to the accumulation of extracellular matrix (ECM). Particularly, there is an increased accumulation of collagen in the fibrotic liver. We have therefore used a triplex forming oligonucleotide (TFO) against the type α 1 (I) collagen and evaluated, whether it can attenuate liver fibrosis induced by common bile duct ligation (CBDL) in rats. There was a significant decrease in hydroxyproline levels and Masson’s trichrome staini...

  6. Different effects of cytoprotective drugs on ethanol- and aspirin-induced gastric mucosal injury in pylorus-ligated rats

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, K.; Nishiwaki, H.; Niida, H.; Okabe, S. (Kyoto Pharmaceutical Univ. (Japan))

    1990-02-01

    In anesthetized rats oral administration (2 ml) of both ethanol (50% in 150 mM HCl) and aspirin (80 mM in 150 mM HCl) produced bandlike lesions in the stomach, while more generalized lesions occurred in the pylorus-ligated stomach when the irritant was given intragastrically through the fistula prepared in the rumen and the mucosal folds were removed by stomach distension. The bandlike lesions induced in the intact stomach by both irritants were significantly and dose-dependently prevented by 16,16-dimethyl PGE2 (dmPGE2: 3 and 10 micrograms/kg, subcutaneously), cysteamine (30 and 100 mg/kg, subcutaneously) or timoprazole (10 and 30 mg/kg, per os) at the doses which significantly inhibited gastric motility. In the pylorus-ligated stomach, however, neither of these agents showed any protection against the generalized lesions induced by ethanol, but such lesions caused by aspirin were significantly prevented only by dmPGE2. These agents also showed similar effects against the reduction of transmucosal PD in the pylorus-ligated stomach exposed to ethanol and aspirin. These results suggest that (1) the formation of bandlike lesions caused by ethanol and aspirin depends on the presence of mucosal folds and may be prevented by the agents that inhibit gastric motility, (2) the pathogenesis of the lesions induced by aspirin and ethanol may be different in the pylorus-ligated stomach, and (3) dmPGE2 has a unique protective ability that is not shared by usual cytoprotective agents.

  7. QuickStep-Cloning: a sequence-independent, ligation-free method for rapid construction of recombinant plasmids

    OpenAIRE

    Jajesniak, Pawel; Wong, Tuck Seng

    2015-01-01

    Background Molecular cloning is an essential step in biological engineering. Methods involving megaprimer-based PCR of a whole plasmid are promising alternatives to the traditional restriction-ligation-based molecular cloning. Their widespread use, however, is hampered by some of their inherent characteristics, e.g., linear amplification, use of self-annealing megaprimers and difficulty with performing point insertion of DNA. These limitations result in low product yield and reduced flexibili...

  8. Gene changes in Duchenne muscular dystrophy: Comparison of multiplex PCR and multiplex ligation-dependent probe amplification techniques

    OpenAIRE

    Kohli Sudha; Saxena Renu; Thomas Elizabeth; Singh Jyoti; Verma Ishwar

    2010-01-01

    Background: Duchenne muscular dystrophy (DMD) is a common X-linked recessive neuromuscular disorder, affecting 1 in 3,500 live male births. About 65% of cases are caused by deletions; ~5% to 8%, by duplication; and the remaining, by point mutations of the dystrophin gene. The frequency of complex rearrangements (double-deletion and non-contiguous duplications) is reported to be 4%. Aim: In this study, we examined the usefulness of multiplex ligation-dependent probe...

  9. A retrospective comparative study of histoacryl injection and banding ligation in the treatment of acute type 1 gastric variceal hemorrhage.

    Science.gov (United States)

    Lo, Gin-Ho; Lin, Chih-Wen; Perng, Daw-Shyong; Chang, Chi-Yang; Lee, Ching-Tai; Hsu, Chuan-Yuan; Wang, Huay-Min; Lin, Hui-Chen

    2013-10-01

    BACKGROUND. Esophageal varices extending along lesser curvature side of stomach is classified as GOV1. The optimal therapy for GOV1 bleeding is still undetermined. METHODS. One hundred and sixty-two patients diagnosed as acute hemorrhage from GOV1 were enrolled. At endoscopists' discretion, 118 patients received glue injection (Glue group) and 44 patients received ligation to arrest bleeding [endoscopic variceal ligation (EVL) group]. This study aimed to compare hemostasis, rebleeding, complications and mortality within 42 days. RESULTS. Both groups were comparable in baseline data. In 109 patients (92%) in the Glue group and 36 patients (82%) in the EVL group (p = 0.07) 48-h hemostasis was achieved . Hemostasis of active bleeding was achieved in 49 of 55 patients (89%) in the Glue group and 24 of 28 patients (85%) in the EVL group (p = 0.70). Treatment failure was noted in 14% of the Glue group and 23% in the EVL group (p = 0.22). Eight patients in the Glue group and four patients in the EVL group rebled between 5 and 42 days (p = 0.73). A total of 48 and 19 adverse events occurred in the Glue and EVL groups, respectively (p = 0.85). Six patients in the Glue group and seven patients in the EVL group encountered posttreatment gastric ulcer bleeding (p = 0.04). Seventeen patients (14%) in the Glue group and 10 (23%) patients in the EVL group died within 42 days (p < 0.001). CONCLUSIONS. Banding ligation was similar to glue injection in achieving successful hemostasis of acute bleeding from GOV1. However, a higher incidence of posttreatment ulcer bleeding and mortality may be associated with banding ligation. PMID:24047398

  10. Predictive mutagenesis of ligation-independent cloning (LIC) vectors for protein expression and site-specific chemical conjugation

    DEFF Research Database (Denmark)

    Vernet, Erik; Sauer, Jørgen; Andersen, Peter Andreas;

    2011-01-01

    Ligation-independent cloning (LIC) allows for cloning of DNA constructs independent of insert restriction sites and ligases. However, any required mutations are typically introduced by additional, time-consuming steps. We present a rapid, inexpensive method for mutagenesis in the 5' LIC site of e......-oxy functionalized polyethylene glycol (PEG) ligand under aniline catalysis to provide a protein selectively modified at the N-terminus....

  11. Native chemical ligation between asparagine and valine: application and limitations for the synthesis of tri-phosphorylated C-terminal tau.

    Science.gov (United States)

    Reimann, Oliver; Glanz, Maria; Hackenberger, Christian P R

    2015-06-15

    We present the successful native chemical ligation (NCL) at an Asn-Val site employing β-mercaptovaline and subsequent desulfurization in the synthesis of native phosphorylated C-terminal tau, relevant for Alzheimer's disease related research. Despite recent progress in the field of NCL we illustrate limitations of this ligation site that stem from thioester hydrolysis and predominantly aspartimide formation. We systematically investigated the influence of pH, temperature, peptide concentration and thiol additives on the outcome of this ligation and identified conditions under which the ligation can be driven toward complete conversion, which required the deployment of a high surplus of thioester. Application of the optimized conditions allowed us to gain access to challenging tri-phosphorylated C-terminal tau peptide in practical yields.

  12. Dentoalveolar mandibular changes with self-ligating versus conventional bracket systems: A CBCT and dental cast study

    Directory of Open Access Journals (Sweden)

    Marcio Rodrigues de Almeida

    2015-06-01

    Full Text Available OBJECTIVE: The aim of the present study was to compare dentoalveolar changes in mandibular arch, regarding transversal measures and buccal bone thickness, in patients undergoing the initial phase of orthodontic treatment with self-ligating or conventional bracket systems. METHODS: A sample of 25 patients requiring orthodontic treatment was assessed based on the bracket type. Group 1 comprised 13 patients bonded with 0.022-in self-ligating brackets (SLB. Group 2 included 12 patients bonded with 0.022-in conventional brackets (CLB. Cone-beam computed tomography (CBCT scans and a 3D program (Dolphin assessed changes in transversal width of buccal bone (TWBB and buccal bone thickness (BBT before (T1 and 7 months after treatment onset (T2. Measurements on dental casts were performed using a digital caliper. Differences between and within groups were analyzed by Student's t-test; Pearson correlation coefficient was also calculated. RESULTS: Significant mandibular expansion was observed for both groups; however, no significant differences were found between groups. There was significant decrease in mandibular buccal bone thickness and transversal width of buccal bone in both groups. There was no significant correlation between buccal bone thickness and dental arch expansion. CONCLUSIONS: There were no significant differences between self-ligating brackets and conventional brackets systems regarding mandibular arch expansion and changes in buccal bone thickness or transversal width of buccal bone.

  13. Restriction-ligation-free (RLF) cloning: a high-throughput cloning method by in vivo homologous recombination of PCR products.

    Science.gov (United States)

    Wang, Y; Liu, Y; Chen, J; Tang, M J; Zhang, S L; Wei, L N; Li, C H; Wei, D B

    2015-01-01

    In this study, we optimized a restriction-ligation-free (RLF) method to save time and cost of constructing multiple plasmids with the same gene insert, and examined the efficacy of RLF on high-throughput multi-plasmid cloning. This method utilizes the precise DNA repair and recombination systems within Escherichia coli, which allows to bypass the in vitro restriction and ligation enzyme reactions commonly included in routine cloning procedures. A homologous arm is linked to the 5'-end of the forward primer used to amplify both the target gene and vector. A different homologous arm is linked to the 5'-end of the reverse primer. Therefore, genes can be cloned into the vectors by homologous recombination after co-transformation of the amplified target gene and the linearized vector, which bear the same homologous arm on either end. More than twenty-four different plasmids were generated by this method, which uses two simple polymerase chain reaction steps. This method is highly efficient in cloning any gene of interest into any vector at any site without sequence constraints, as no restriction and ligation reactions are required. PMID:26505379

  14. Pathological study on the effect of vitamin D3 on sepsis experimentally induced in rats by cecal ligation and punctures

    Directory of Open Access Journals (Sweden)

    A.M. Al-Saidya

    2014-06-01

    Full Text Available The aim of this study was to investigate the effects of the Vitamin D3 on the rats with sepsis that experimentally induced by cecal ligation and puncture. 100 Rats were divided into 5 groups, these include untreated control group, sham-operated group, CLP group and 2 treated groups pretreated daily a Subcutaneous injections of 1,25-dihydroxyvitamin D3 100 ng/kg for 3 days, then one of the pretreated groups subjected to sepsis accomplished by abdominal surgery comprising a cecal ligation and puncture. The following parameters were recorded: survival rate, hematological examinations and histopathological changes of the liver and heart were examined. It was found that vitamin D3 pretreated showed improvement in the survival rats and enhancement in the blood leukocyte count, also protect the rats from thrombocytopenia and Disseminated Intravascular Coagulation (DIC, but vitamin D3 pretreated show slight improvement in the histopathological lesions in the liver and heart due to cecal ligation and puncture sepsis.

  15. Replication-Coupled PCNA Unloading by the Elg1 Complex Occurs Genome-wide and Requires Okazaki Fragment Ligation

    Directory of Open Access Journals (Sweden)

    Takashi Kubota

    2015-08-01

    Full Text Available The sliding clamp PCNA is a crucial component of the DNA replication machinery. Timely PCNA loading and unloading are central for genome integrity and must be strictly coordinated with other DNA processing steps during replication. Here, we show that the S. cerevisiae Elg1 replication factor C-like complex (Elg1-RLC unloads PCNA genome-wide following Okazaki fragment ligation. In the absence of Elg1, PCNA is retained on chromosomes in the wake of replication forks, rather than at specific sites. Degradation of the Okazaki fragment ligase Cdc9 leads to PCNA accumulation on chromatin, similar to the accumulation caused by lack of Elg1. We demonstrate that Okazaki fragment ligation is the critical prerequisite for PCNA unloading, since Chlorella virus DNA ligase can substitute for Cdc9 in yeast and simultaneously promotes PCNA unloading. Our results suggest that Elg1-RLC acts as a general PCNA unloader and is dependent upon DNA ligation during chromosome replication.

  16. Safety and Effectiveness of Endovenous Laser Ablation Combined With Ligation for Severe Saphenous Varicose Veins in Japanese Patients.

    Science.gov (United States)

    Izumi, Masafumi; Ikeda, Yuichi; Yamashita, Hiroharu; Asaoka, Yoshinari; Fujishiro, Mitsuhiro; Shin, Masahiro; Abo, Yoshihisa

    2016-01-01

    Endovenous laser ablation (EVLA), which is a relatively new therapeutic option for saphenous varicose veins of the legs, is less invasive than conventional stripping surgery with ligation. In this study, we evaluated the safety and effectiveness of EVLA combined with ligation for severe saphenous varicose veins that were graded as ≥ C4 by the CEAP classification. We treated 119 Japanese patients (141 limbs) between July 2005 and December 2007 utilizing a 1320-nm Nd:YAG laser. The obliteration rate of the treated veins was found to be 100% over the entire follow-up period (2.5 years). Consistent with this finding, all of the patients exhibited improved skin lesions (ie, skin pigmentation and ulceration). No major complications, including deep vein thrombosis (DVT) and nerve injury, were observed. A questionnaire survey with a reasonable response rate (66.4%) demonstrated that subjective symptoms and minor complications that were initially observed after EVLA, such as mild pain, numbness, indurations, and localized hot flashes, were remarkably improved by the end of the follow-up period. Furthermore, high levels of patient satisfaction were noted. Thus, EVLA combined with ligation constituted a safe and effective strategy for treating severe saphenous varicose veins in Japanese patients.

  17. Synthesis, characterization, and energetic properties of 6-amino-tetrazolo[1,5-b]-1,2,4,5-tetrazine-7-N-oxide: a nitrogen-rich material with high density.

    Science.gov (United States)

    Wei, Hao; Zhang, Jiaheng; Shreeve, Jean'ne M

    2015-05-01

    The synthesis and energetic properties of a novel N-oxide high-nitrogen compound, 6-amino-tetrazolo[1,5-b]-1,2,4,5-tetrazine-7-N-oxide, are described. Resulting from the N-oxide and fused rings system, this molecule exhibits high density, excellent detonation properties, and acceptable impact and friction sensitivities, which suggests potential applications as an energetic material. Compared to known high-nitrogen compounds, such as 3,6-diazido-1,2,4,5-tetrazine (DiAT), 2,4,6-tri(azido)-1,3,5-triazine (TAT), and 4,4',6,6'-tetra(azido)azo-1,3,5-triazine (TAAT), a marked performance and stability increase is seen. This supports the superior qualities of this new compound and the advantage of design strategy.

  18. Nitrogen Trading Tool (NTT)

    Science.gov (United States)

    The Natural Resources Conservation Service (NRCS) recently developed a prototype web-based nitrogen trading tool to facilitate water quality credit trading. The development team has worked closely with the Agriculture Research Service Soil Plant Nutrient Research Unit (ARS-SPNR) and the Environmenta...

  19. Nitrogen Fixation in Cyanobacteria

    NARCIS (Netherlands)

    Stal, L.J.

    2015-01-01

    Cyanobacteria are oxygenic photosynthetic bacteria that are widespread in marine, freshwater and terrestrial environments, and many of them are capable of fixing atmospheric nitrogen. However, ironically, nitrogenase, the enzyme that is responsible for the reduction of N2, is extremely sensitive to

  20. Slow magnetic relaxation in four square-based pyramidal dysprosium hydroxo clusters ligated by chiral amino acid anions - a comparative study.

    Science.gov (United States)

    Thielemann, Dominique T; Wagner, Anna T; Lan, Yanhua; Anson, Christopher E; Gamer, Michael T; Powell, Annie K; Roesky, Peter W

    2013-10-01

    The synthesis and characterization of three chiral and one achiral amino acid anion ligated dysprosium hydroxo clusters [Dy5(OH)5(α-AA)4(Ph2acac)6] (α-AA = d-PhGly, l-Pro, l-Trp, Ph2Gly; Ph2acac = dibenzoylmethanide) are reported. The solid state structures were determined using single crystal X-ray diffraction and show that five Dy(iii) ions are arranged in a square-based pyramidal geometry with NO7-donor-sets for the basal and O8-donor-sets for the apical Dy atom. Both static (dc) and dynamic (ac) magnetic properties were investigated for all four compounds and show a slow relaxation of magnetization, indicative of single molecule magnet (SMM) behaviour below 10 K in all cases. The similar SMM behaviour observed for all four compounds suggests that the very similar coordination geometries seen for the dysprosium atoms in all members of this family, which are independent of the amino acid ligand used, play a decisive role in steering the contribution of the single ion anisotropies to the observed magnetic relaxation. PMID:23986134

  1. Cystathionine-γ-lyase gene silencing with siRNA in monocytes/ macrophages attenuates inflammation in cecal ligation and puncture-induced sepsis in the mouse

    Indian Academy of Sciences (India)

    A Badiei; ST Chambers; RR Gaddam; M Bhatia

    2016-03-01

    Hydrogen sulphide is an endogenous inflammatory mediator produced by cystathionine-γ-lyase (CSE) in macrophages. To determine the role of H2S and macrophages in sepsis, we used small interference RNA (siRNA) to target the CSE gene and investigated its effect in a mouse model of sepsis. Cecal ligation puncture (CLP)-induced sepsis is characterized by increased levels of myeloperoxidase (MPO) activity, morphological changes in liver and pro-inflammatory cytokines and chemokines in the liver and lung. SiRNA treatment attenuated inflammation in the liver and lungs of mice following CLP-induced sepsis. Liver MPO activity increased in CLP-induced sepsis and treatment with siRNA significantly reduced this. Similarly, lung MPO activity increased following induction of sepsis with CLP while siRNA treatment significantly reduced MPO activity. Liver and lung cytokine and chemokine levels in CLP-induced sepsis reduced following treatment with siRNA. These findings show a crucial pro-inflammatory role for H2S synthesized by CSE in macrophages in sepsis and suggest CSE gene silencing with siRNA as a potential therapeutic approach for this condition.

  2. The Inhibitory Effect of Non-Substrate and Substrate DNA on the Ligation and Self-Adenylylation Reactions Catalyzed by T4 DNA Ligase.

    Science.gov (United States)

    Bauer, Robert J; Evans, Thomas C; Lohman, Gregory J S

    2016-01-01

    DNA ligases are essential both to in vivo replication, repair and recombination processes, and in vitro molecular biology protocols. Prior characterization of DNA ligases through gel shift assays has shown the presence of a nick site to be essential for tight binding between the enzyme and its dsDNA substrate, with no interaction evident on dsDNA lacking a nick. In the current study, we observed a significant substrate inhibition effect, as well as the inhibition of both the self-adenylylation and nick-sealing steps of T4 DNA ligase by non-nicked, non-substrate dsDNA. Inhibition by non-substrate DNA was dependent only on the total DNA concentration rather than the structure; with 1 μg/mL of 40-mers, 75-mers, or circular plasmid DNA all inhibiting ligation equally. A >15-fold reduction in T4 DNA ligase self-adenylylation rate when in the presence of high non-nicked dsDNA concentrations was observed. Finally, EMSAs were utilized to demonstrate that non-substrate dsDNA can compete with nicked dsDNA substrates for enzyme binding. Based upon these data, we hypothesize the inhibition of T4 DNA ligase by non-nicked dsDNA is direct evidence for a two-step nick-binding mechanism, with an initial, nick-independent, transient dsDNA-binding event preceding a transition to a stable binding complex in the presence of a nick site.

  3. Recent Research Progress of Cecal Ligation and Puncture%盲肠结扎穿孔术-脓毒症模型研究的金标准

    Institute of Scientific and Technical Information of China (English)

    黄鑫(综述); 张敏州(审校)

    2015-01-01

    Sepsis is a high incidence and high mortality of the disease ,which is characterized by dysreg-ulated systemic in ammatory responses followed by immunosuppression , so how to choose the best animal model for the study of sepsis is crucial.Sepsis induced by cecal ligation and puncture ( CLP) is the most widely used model.Although CLP does not completely reproduce the complexity of human sepsis,the CLP model is one of the best representations of human sepsis which has made important contributions to our knowledge of the in ammation involved in sepsis and to the identi cation of therapeutic strategies .In this pa-per we gathered these datas on the cecal ligation and puncture-induced sepsis model for a review to narrow the gap between experimental sepsis models and clinical sepsis.%脓毒症是一个高发病率、高病死率的疾病。其发病特点是全身炎性反应失调引起的免疫功能障碍,因此如何选择最佳动物模型对研究脓毒症至关重要。盲肠结扎穿孔模型( CLP)是目前研究脓毒症应用最广泛、最具代表意义的一种模型,更类似于人类脓毒症的进展和特点。尽管 CLP 不能完全复制临床的脓毒症,但其仍为脓毒症发病机制和防治研究提供了大量有意义的基础数据。该文对盲肠结扎穿孔术模型的研究应用予以综述,以促进实验研究与临床试验间的转化。

  4. Comparison of myocardial infarction with sequential ligation of the left anterior descending artery and its diagonal branch in dogs and sheep.

    Science.gov (United States)

    Kim, W G; Shin, Y C; Hwang, S W; Lee, C; Na, C Y

    2003-04-01

    We report a comparison of the effects of myocardial infarction in dogs and sheep using sequential ligation of the left anterior descending artery (LAD) and its diagonal branch (DA), with hemodynamic, ultrasonographic and pathological evaluations. Five animals were used in each group. After surgical preparation, the LAD was ligated at a point approximately 40% of the distance from the apex to the base of the heart, and after one hour, the DA was ligated at the same level. Hemodynamic and ultrasonographic measurements were performed preligation, 30 minutes after LAD ligation, and 1 hour after DA ligation. As a control, two animals in each group were used for the simultaneous ligation of the LAD and the DA. Two months after the coronary ligation, the animals were evaluated as previously, and killed for postmortem examination of their hearts. All seven animals in the dog group survived the experimental procedures, while in the sheep group only animals with sequential ligation of the LAD and DA survived. Statistically significant decreases in systemic arterial blood pressure and cardiac output, and an increase in the pulmonary artery capillary wedge pressure (PACWP) were observed one hour after sequential ligation of the LAD and its DA in the sheep, while only systemic arterial pressures decreased in the dog. Ultrasonographic analyses demonstrated variable degrees of anteroseptal dyskinesia and akinesia in all sheep, but in no dogs. Data two months after coronary artery ligation showed significant increases in central venous pressure, pulmonary artery pressure, and PACWP in the sheep, but not in the dog. Left ventricular end-diastolic dimension and left ventricular end-systolic dimension in ultrasonographic studies were also increased only in the sheep. Pathologically, the well-demarcated thin-walled transmural anteroseptal infarcts with chamber enlargement were clearly seen in all specimens of sheep, and only-mild-to-moderate chamber enlargements with endocardial

  5. T-linker-specific ligation PCR (T-linker PCR): an advanced PCR technique for chromosome walking or for isolation of tagged DNA ends

    OpenAIRE

    Yuanxin, Yan; Chengcai, An; Li, Li; Jiayu, Gu; Guihong, Tan; Zhangliang, Chen

    2003-01-01

    Dozens of PCR-based methods are available for chromosome walking from a known sequence to an unknown region. These methods are of three types: inverse PCR, ligation-mediated PCR and randomly primed PCR. However, none of them has been generally applied for this purpose, because they are either difficult or inefficient. Here we describe a simple and efficient PCR strategy—T-linker-specific ligation PCR (T-linker PCR) for gene or chromosome walking. The strategy amplifies the template molecules ...

  6. A novel mode of human immunodeficiency virus type 1 (HIV-1) activation: ligation of CD28 alone induces HIV-1 replication in naturally infected lymphocytes.

    OpenAIRE

    1993-01-01

    Induction of human immunodeficiency virus (HIV) replication in infected CD4+ T lymphocytes requires cellular activation. The ligation of CD28, a signal-transducing receptor with a natural ligand on activated B cells and antigen-presenting cells, provides a costimulating signal for interleukin 2 production and T-cell proliferation as well as coactivation of the transfected HIV long terminal repeat in Jurkat cells. The aim of the present study was to investigate the ability of CD28 ligation to ...

  7. The comparison of frictional resistance in titanium, self-ligating stainless steel, and stainless steel brackets using stainless steel and TMA archwires: An in vitro study

    OpenAIRE

    Syed Altaf Khalid; Vadivel Kumar; Prithviraj Jayaram

    2012-01-01

    Aim: The aim of the study was to compare the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and titanium molybdenum alloy (TMA) archwires. Materials and Methods: We compared the frictional resistance in 0.018 slot and 0.022 slot of the three brackets - titanium, self-ligating stainless steel, and conventional stainless steel - using stainless steel archwires and TMA archwires. An in vitro study of simulated ca...

  8. Characterization and catalytic performance of CeO2-Co/SiO2 catalyst for Fischer-Tropsch synthesis using nitrogen-diluted synthesis gas over a laboratory scale fixed-bed reactor

    Institute of Scientific and Technical Information of China (English)

    Xiaoping Dai; Changchun Yu

    2008-01-01

    The surface species of CO hydrogenation on CeO2-Co/SiO2 catalyst were investigated using the techniques of temperature programmed reaction and transient response method. The results indicated that the formation of H2O and CO2 was the competitive reaction for the surface oxygen species, CH4 was produced via the hydrogenation of carbon species step by step, and C2 products were formed by the polymerization of surface-active carbon species (-CH2-). Hydrogen assisted the dissociation of CO. The hydrogenation of surface carbon species was the rate-limiting step in the hydrogenation of CO over CeO2-Co/SiO2 catalyst. The investigation of total pressure, gas hourly space velocity (GHSV), and product distribution using nitrogen-rich synthesis gas as feedstock over a laboratory scale fixed-bed reactor indicated that total pressure and GHSV had a significant effect on the catalytic performance of CeO2-Co/SiO2 catalyst. The removal of heat and control of the reaction temperature were extremely critical steps, which required lower GHSV and appropriate CO conversion to avoid the deactivation of the catalyst. The feedstock of nitrogen-rich synthesis gas was favorable to increase the conversion of CO, but there was a shift of product distribution toward the light hydrocarbon. The nitrogen-rich synthesis gas was feasible for F-T synthesis for the utilization of remote natural gas.

  9. Utilization of Non-Destructive Thermoelectric Power Measurements for Determination of Interstitial Nitrogen Content in Nitrogen-Strengthened Austenitic Stainless Steel Welds

    International Nuclear Information System (INIS)

    Through utilization of modern physics concepts, a new non-destructive, portable thermoelectric power device has been designed for the use of rapid material characterization in nitrogen-strengthened austenitic stainless steel weldments. Nitrogen is used as an interstitial strengthener in austenitic stainless steel offering enhancement in mechanical properties and corrosion resistance. A direct correlation exists between the thermoelectric power coefficient as a function of interstitial nitrogen content, revealing microstructural characteristics of the austenitic stainless steel weldment

  10. Behavioral deficits in sepsis-surviving rats induced by cecal ligation and perforation

    Directory of Open Access Journals (Sweden)

    T. Barichello

    2007-06-01

    Full Text Available Sepsis and its complications are the leading causes of mortality in intensive care units, accounting for 10-50% of deaths. Intensive care unit survivors present long-term cognitive impairment, including alterations in memory, attention, concentration, and/or global loss of cognitive function. In the present study, we investigated behavioral alterations in sepsis-surviving rats. One hundred and ten male Wistar rats (3-4 months, 250-300 g were submitted to cecal ligation and puncture (CLP, and 44 were submitted to sham operation. Forty-four rats (40% survived after CLP, and all sham-operated animals survived and were used as control. Twenty animals of each group were used in the object recognition task (10 in short-term memory and 10 in long-term memory, 12 in the plus-maze test and 12 in the forced swimming test. Ten days after surgery, the animals were submitted individually to an object recognition task, plus-maze and forced swimming tests. A significant impairment of short- and long-term recognition memory was observed in the sepsis group (recognition index 0.75 vs 0.55 and 0.74 vs 0.51 for short- and long-term memory, respectively (P < 0.05. In the elevated plus-maze test no difference was observed between groups in any of the parameters assessed. In addition, sepsis survivors presented an increase in immobility time in the forced swimming test (180 vs 233 s, P < 0.05, suggesting the presence of depressive-like symptoms in these animals after recovery from sepsis. The present results demonstrated that rats surviving exposure to CLP, a classical sepsis model, presented recognition memory impairment and depressive-like symptoms but not anxiety-like behavior.

  11. Aqueous garlic extract alleviates liver fibrosis and renal dysfunction in bile-duct-ligated rats.

    Science.gov (United States)

    Mahmoud, Mona F; Zakaria, Sara; Fahmy, Ahmed

    2014-01-01

    There is accumulating evidence that the renin-angiotensin system (RAS) is involved in hepatic inflammation and fibrogenesis. Garlic was found to lower the activity of the angiotensin converting enzyme (ACE) in the serum of rats in a diabetic model. We examined the effect of an aqueous garlic extract (AGE) on the ACE activity, cholestasis-induced liver fibrosis, and associated renal dysfunction in comparison with the effect of the standard drug enalapril. Both AGE and enalapril were administered orally for six weeks starting from the third day after bile duct ligation (BDL). BDL significantly increased the serum activities of liver enzymes, serum lactate dehydrogenase (LDH) activity, an indicator of liver cell death, serum total bilirubin (TB) level, liver myeloperoxidase (MPO) activity, and liver malondialdehyde (MDA) content. BDL was associated with elevation of serum urea and creatinine levels indicating renal dysfunction. BDL also caused an increase in the transcript levels of the genes coding for tumour necrosis factor alpha (TNF-alpha), transforming growth factor beta-1 (TGF-beta1), and matrix metalloproteinase-13 (MMP-13), a collagenase, in liver tissues. A significant decrease in hepatic reduced glutathione (GSH) was observed in BDL rats, while serum ACE activity was increased. Both AGE and enalapril counteracted all these deleterious changes, with the exception that only AGE reduced the MPO activity. These findings suggest that AGE possesses hepato- and renoprotective properties, similar to enalapril, probably by modulating the levels of proteins such as TNF-alpha, TGF-beta1 and MMP-13, and involving a reduction of ACE and of oxidative stress. PMID:24873034

  12. Association of overactive bladder and stress urinary incontinence in rats with pudendal nerve ligation injury.

    Science.gov (United States)

    Furuta, Akira; Kita, Masafumi; Suzuki, Yasuyuki; Egawa, Shin; Chancellor, Michael B; de Groat, William C; Yoshimura, Naoki

    2008-05-01

    Approximately one-third of patients with stress urinary incontinence (SUI) also suffer from urgency incontinence, which is one of the major symptoms of overactive bladder (OAB) syndrome. Pudendal nerve injury has been recognized as a possible cause for both SUI and OAB. Therefore, we investigated the effects of pudendal nerve ligation (PNL) on bladder function and urinary continence in female Sprague-Dawley rats. Conscious cystometry with or without capsaicin pretreatment (125 mg/kg sc), leak point pressures (LPPs), contractile responses of bladder muscle strips to carbachol or phenylephrine, and levels of nerve growth factor (NGF) protein and mRNA in the bladder were compared in sham and PNL rats 4 wk after the injury. Urinary frequency detected by a reduction in intercontraction intervals and voided volume was observed in PNL rats compared with sham rats, but it was not seen in PNL rats with capsaicin pretreatment that desensitizes C-fiber-afferent pathways. LPPs in PNL rats were significantly decreased compared with sham rats. The contractile responses of detrusor muscle strips to phenylephrine, but not to carbachol, were significantly increased in PNL rats. The levels of NGF protein and mRNA in the bladder of PNL rats were significantly increased compared with sham rats. These results suggest that pudendal nerve neuropathy induced by PNL may be one of the potential risk factors for OAB, as well as SUI. Somato-visceral cross sensitization between somatic (pudendal) and visceral (bladder) sensory pathways that increases NGF expression and alpha(1)-adrenoceptor-mediated contractility in the bladder may be involved in this pathophysiological mechanism.

  13. Dietary glycine blunts liver injury after bile duct ligation in rats

    Institute of Scientific and Technical Information of China (English)

    Matthias Froh; Juirgen Scholmerich; Ronald G Thurman; Zhi Zhong; Peter Walbrun; Mark Lehnert; Susanne Netter; Reiner Wiest; Lars Conzelmann; Erwin Gaibele; Claus Hellerbrand

    2008-01-01

    AIM: To investigate the effects of (dietary) glycine against oxidant-induced injury caused by bile duct ligation (BDL).METHODS: Either a diet containing 5% glycine or a standard diet was fed to male Sprague-Dawley (SD) rats. Three days later, BDL or sham-operation was performed. Rats were sacrificed 1 to 3 d after BDL. The influence of deoxycholic acid (DCA) in the presence or absence of glycine on liver cells was determined by measurement of calcium and chloride influx in cultivated Kupffer cells and lactate dehydrogenase (LDH) activity was determined in the supernatant of cultivated hepatocytes.RESULTS: Serum alanine transaminase levels increased to about 600 U/L 1 d after BDL. However, enzyme release was blunted by about two third in rats receiving glycine. Release of the alkaline phosphatase and aspartate aminotransferase was also blocked significantly in the group fed glycine. Focal necrosis was observed 2 d after BDL. Glycine partially blocked the histopathological changes. Incubation of Kupffer cells with DCA led to increased intracellular calcium that could be blocked by incubation with glycine. However, systemic blockage of Kupffer cells with gadolinium chloride had no effects on transaminase release. Incubation of isolated hepatocytes with DCA led to a significant release of LDH after 4 h. This release was largely blocked when incubation with glycine was performed.CONCLUSION: These data indicate that glycine significantly decreased liver injury, most likely by a direct effect on hepatocytes. Kupffer cells do not appear to play an important role in the pathological changes caused by cholestasis.

  14. Bile duct ligation in rats: A reliable model of hepatorenal syndrome?

    Institute of Scientific and Technical Information of China (English)

    Stelios F Assimakopoulos; Constantine E Vagianos

    2009-01-01

    The two most widely used experimental models of advanced liver disease are the administration of carbon tetrachloride, and common bile duct ligation (BDL), however, neither has been systematically evaluated as a model of hepatorenal syndrome (HRS). The BDL model in rats, studied at diverse time points, induced a progressive renal dysfunction without structural changes in the kidney. The authors concluded that BDL is a good model for further studies of HRS and its treatment. However, the renal impairment observed at the acute phase of the BDL model is based on a different pathophysiology than that of HRS. Specifically, in acute obstructive jaundice, cholemia predominates over parenchymal liver disease (reversible at this stage without portal hypertension or cirrhosis) and independently induces negative inotropic and chronotropic effects on the heart,impaired sympathetic vasoconstriction response and profound natriuresis and diuresis that might lead to volume depletion. In addition, systemic endotoxemia contributes to the prerenal etiology of renal impairment and promotes direct nephrotoxicity and acute tubular necrosis. On the other hand, the renal failure observed in the chronic BDL model (with development of biliary cirrhosis, portal hypertension and ascites) shares pathophysiological similarities with HRS, but the accordance of the chronic BDL model to the diagnostic criteria of HRS (e.g. absence of spontaneous bacterial peritonitis, no renal function improvement after plasma volume expansion) should have been confirmed. In conclusion, we think that the BDL model is not suitable for the study of the natural history of HRS, but the chronic BDL model might be valid for the study of established HRS and its potential therapies.

  15. Comparison of murine cirrhosis models induced by hepatotoxin administration and common bile duct ligation

    Institute of Scientific and Technical Information of China (English)

    Ming-Ling Chang; Chau-Ting Yeh; Pei-Yeh Chang; Jeng-Chang Chen

    2005-01-01

    AIM: To build up the research models of hepatic fibrosis in mice.METHODS: Inbred wild-type FVB/N mice were either treated with alpha-naphthyl-isothiocyanate (ANIT), allyl alcohol (AA),carbon tetrachloride (CCl4), 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC), and silica, or subjected to common bile duct ligation (CBDL) to induce hepatic injury. Liver biopsies were performed every 4 wk to evaluate hepatic fibrosis over a period of 6 mo. Cumulative cirrhosis and survival curves were constructed by life table method and compared with Wilcoxon test.RESULTS: Under the dosages used, there was neither mortality nor cirrhosis in AA and silica-treated groups. DDC and ANIT caused cirrhosis within 4-12 and 12-24 wk, respectively.Both showed significantly faster cirrhosis induction at high dosages without significant alteration of survival. The duration for cirrhosis induction by CCl4 ranged from 4 to 20 wk, mainly dependent upon the dosage. However, the increase in CCl4dosage significantly worsened survival. Intraperitoneal CCl4administration resulted in better survival in comparison with gavage administration at high dosage, but not at medium and low dosages. After CBDL, all the mice developed liver cirrhosis within 4-8 wk and then died by the end of 16 wk.CONCLUSION: CBDL and administrations of ANIT, CCl4, and DDC ensured liver cirrhosis. CBDL required the least amount of time in cirrhosis induction, but caused shortened lives of mice. It was followed by DDC and ANIT administration with favorable survival. As for CCl4, the speed of cirrhosis induction and the mouse survival depended upon the dosages and the administration route.

  16. Pathophysiology of lung injury induced by common bile duct ligation in mice.

    Directory of Open Access Journals (Sweden)

    Fumiaki Shikata

    Full Text Available BACKGROUND: Liver dysfunction and cirrhosis affect vasculature in several organ systems and cause impairment of organ functions, thereby increasing morbidity and mortality. Establishment of a mouse model of hepatopulmonary syndrome (HPS would provide greater insights into the genetic basis of the disease. Our objectives were to establish a mouse model of lung injury after common bile duct ligation (CBDL and to investigate pulmonary pathogenesis for application in future therapeutic approaches. METHODS: Eight-week-old Balb/c mice were subjected to CBDL. Immunohistochemical analyses and real-time quantitative reverse transcriptional polymerase chain reaction were performed on pulmonary tissues. The presence of HPS markers was detected by western blot and microarray analyses. RESULTS: We observed extensive proliferation of CD31-positive pulmonary vascular endothelial cells at 2 weeks after CBDL and identified 10 upregulated and 9 down-regulated proteins that were associated with angiogenesis. TNF-α and MMP-9 were highly expressed at 3 weeks after CBDL and were less expressed in the lungs of the control group. CONCLUSIONS: We constructed a mouse lung injury model by using CBDL. Contrary to our expectation, lung pathology in our mouse model exhibited differences from that of rat models, and the mechanisms responsible for these differences are unknown. This phenomenon may be explained by contrasting processes related to TNF induction of angiogenic signaling pathways in the inflammatory phase. Thus, we suggest that our mouse model can be applied to pulmonary pathological analyses in the inflammatory phase, i.e., to systemic inflammatory response syndrome, acute lung injury, and multiple organ dysfunction syndrome.

  17. Tetrathiomolybdate protects against bile duct ligation-induced cholestatic liver injury and fibrosis.

    Science.gov (United States)

    Song, Ming; Song, Zhenyuan; Barve, Shirish; Zhang, Jingwen; Chen, Theresa; Liu, Marcia; Arteel, Gavin E; Brewer, George J; McClain, Craig J

    2008-05-01

    Tetrathiomolybdate (TM), a potent copper-chelating drug, was initially developed for the treatment of Wilson's disease. Our working hypothesis is that the fibrotic pathway is copper-dependent. Because biliary excretion is the major pathway for copper elimination, a bile duct ligation (BDL) mouse model was used to test the potential protective effects of TM. TM was given in a daily dose of 0.9 mg/mouse by means of intragastric gavage 5 days before BDL. All the animals were killed 5 days after surgery. Plasma liver enzymes and total bilirubin were markedly decreased in TM-treated BDL mice. TM also inhibited the increase in plasma levels of tumor necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta1 seen in BDL mice. Cholestatic liver injury was markedly attenuated by TM treatment as shown by histology. Hepatic collagen deposition was significantly decreased, and it was paralleled by a significant suppression of hepatic smooth muscle alpha-actin and fibrogenic gene expression in TM-treated BDL mice. Although the endogenous antioxidant ability was enhanced, oxidative stress as shown by malondialdehyde and 4-hydroxyalkenals, hepatic glutathione/oxidized glutathione ratio, was not attenuated by TM treatment, suggesting the protective mechanism of TM may be independent of oxidative stress. In summary, TM attenuated BDL-induced cholestatic liver injury and fibrosis in mice, in part by inhibiting TNF-alpha and TGF-beta1 secretion. The protective mechanism seems to be independent of oxidative stress. Our data provide further evidence that TM might be a potential therapy for hepatic fibrosis.

  18. Effect of nitrogen on blood compatibility of nickel-free high nitrogen stainless steel for biomaterial

    International Nuclear Information System (INIS)

    The aim of this paper was to study the effect of nitrogen content on blood compatibility including platelet adhesion and kinetic clotting time of nickel-free high nitrogen stainless steel (HNS), also in comparison with a conventional austenitic stainless steel AISI 317L. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface chemical composition. The surface wettability and surface free energy (SFE) of these materials were characterized by water contact angle (WCA) measurement to analysis the relationship between surface properties and blood compatibility. Kinetic clotting time was used to evaluate the blood coagulation for these materials and platelet adhesion was assessed by scanning electron microscopy (SEM). The results showed that more platelets adhered on the surface of 317L stainless steel than that on HNS, and with the increase of nitrogen content, the amount of adherent platelets was further decreased on the surface of HNS. Kinetic clotting time results also showed the increased nitrogen content extended the initial clotting time of HNS. The results of surface properties also explained the effect of nitrogen on blood compatibility by traditional theory of SFE and interfacial energy.

  19. Molecular characterization of nitrogen-fixing bacteria isolated from brazilian agricultural plants at São Paulo state Caracterização molecular de bactérias fixadoras de nitrogênio isoladas de plantas brasileiras no estado de São Paulo

    Directory of Open Access Journals (Sweden)

    Érica. L. Reinhardt

    2008-09-01

    Full Text Available Fourteen strains of nitrogen-fixing bacteria were isolated from different agricultural plant species, including cassava, maize and sugarcane, using nitrogen-deprived selective isolation conditions. Ability to fix nitrogen was verified by the acetylene reduction assay. All potentially nitrogen-fixing strains tested showed positive hybridization signals with a nifH probe derived from Azospirillum brasilense. The strains were characterized by RAPD, ARDRA and 16S rDNA sequence analysis. RAPD analyses revealed 8 unique genotypes, the remaining 6 strains clustered into 3 RAPD groups, suggesting a clonal origin. ARDRA and 16S rDNA sequence analyses allowed the assignment of 13 strains to known groups of nitrogen-fixing bacteria, including organisms from the genera Azospirillum, Herbaspirillum, Pseudomonas and Enterobacteriaceae. Two strains were classified as Stenotrophomonas ssp. Molecular identification results from 16S rDNA analyses were also corroborated by morphological and biochemical data.Quatorze linhagens de bactérias fixadoras de nitrogênio foram isoladas de diferentes espécies de plantas, incluindo cassava, milho e cana-de-açúcar, usando condições seletivas desprovidas de nitrogênio. A capacidade de fixar nitrogênio foi verificada por ensaio de redução de acetileno. Todas as linhagens fixadoras de nitrogênio testadas apresentaram hibridização positiva com sonda de gene nifH derivada de Azospirillum brasilense. As linhagens foram caracterizadas por RAPD, ARDRA e sequenciamento do gene 16S rDNA. As análises de RAPD revelaram 8 genótipos, as 6 linhagens restantes foram agrupadas em 3 grupos de RAPD, sugerindo uma origem clonal. ARDRA e seqüências de 16S rDNA foram alocadas em 13 grupos conhecidos de bactérias fixadoras de nitrogênio, incluindo organismos dos gêneros Azospirillum, Herbaspirillum, Pseudomonas e Enterobacteriaceae. Duas linhagens foram classificadas como Stenotrophomonas ssp. Os resultados da identifica

  20. Soil and fertilizer nitrogen

    International Nuclear Information System (INIS)

    As a result of the intensified practices and effectively diminishing land resources per capita, increasing weights of both native soil- and added fertilizer-nitrogen will be lost to agriculture and its products, and will find their way into the environment. Soil-nitrogen levels and contingent productivity can nevertheless be maintained in the face of these losses on the basis of improved soil-N management. In some local situations nitrate levels in water for drinking purposes are likely to continue rising. In some cases agriculture and clearance practices are only one of several sources. In others they are clearly mainly responsible. In developing countries these losses represent those of a relatively increasingly costly input. This is due to the fact that industrial fertilizer nitrogen production is a particularly high energy-consuming process. In the more advanced industrialized countries they represent an addition to the problems and costs of environmental quality and health protection. The programmes, information and data reviewed here suggest that these problems can be contained by improved and extended soil and water management in agriculture on the basis of existing technology. In particular there appears to be enormous scope for the better exploitation of existing legumes both as non-legume crop alternatives or as biofertilizers which also possess more desirable C:N ratios than chemical fertilizer