A new spiral structure associated with the flagellum of Azospirillum lipoferum

1981 ◽  
Vol 27 (12) ◽  
pp. 1267-1271
Author(s):  
Eeva-Liisa Nurmiaho-Lassila ◽  
Kielo Haahtela ◽  
Veronica Sundman
Keyword(s):  
Liquid Culture ◽  
Culture Medium ◽  
Spiral Structure ◽  
Polar Flagellum ◽  
Azospirillum Lipoferum ◽  
Spiral Structures

N2-fixing strains of Azospirillum lipoferum, when grown in liquid culture, produce spiral structures, here named "spirae." The diameter of a spira varies between 40 and 55 nm and its length is variable. Each spira consists of a single helical thread, approximately 5 nm in diameter. These spirae are either attached to the cell, mostly wound around the single polar flagellum, or unattached in the culture medium.

Isolation of previously uncultured rumen bacteria by dilution to extinction using a new liquid culture medium

2011 ◽  
Vol 84 (1) ◽  
pp. 52-60 ◽  
Author(s):  
Nikki Kenters ◽  
Gemma Henderson ◽  
Jeyamalar Jeyanathan ◽  
Sandra Kittelmann ◽  
Peter H. Janssen
Keyword(s):  
Liquid Culture ◽  
Culture Medium ◽  
Rumen Bacteria ◽  
Liquid Culture Medium

scholarly journals Threefold Spiral Structure Constructed by 1D Chains of [[M(NCS)2(bpa)2]·biphenyl]n (M = Fe, Co; bpa = 1,2-bis(4-pyridyl)ethane)

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 97 ◽  
Author(s):  
Satoshi Tokinobu ◽  
Haruka Dote ◽  
Satoru Nakashima
Keyword(s):  
Spin Crossover ◽  
Spiral Structure ◽  
Diffusion Method ◽  
Central Metal ◽  
X Ray ◽  
Pyridine Complex ◽  
1D Chain ◽  
One Step ◽  
Spiral Structures ◽  
1D Chains

Assembled complexes [[M(NCS)2(bpa)2]·biphenyl]n (M = Fe, Co; bpa = 1,2-bis(4-pyridyl)ethane) have been synthesized because [Fe(NCBH3)2(bpa)2·biphenyl]n has a novel threefold spiral structure and shows stepwise spin-crossover phenomenon. We attempted to obtain spiral structures for [[Fe(NCS)2(bpa)2]·biphenyl]n and [[Co(NCS)2(bpa)2]·biphenyl]n using a one-step diffusion method, while the reported spiral structure of [[Fe(NCBH3)2(bpa)2]·biphenyl]n was obtained by diffusion method after synthesizing Fe(II)-pyridine complex. X-ray structural analysis revealed that [[Fe(NCS)2(bpa)2]·biphenyl]n and [[Co(NCS)2(bpa)2]·biphenyl]n had a chiral propeller structure of pyridines around the central metal, and they had a novel spiral structure and chiral space group P3121 without the presence of chiral auxiliaries. It was shown that the host 1D chain, having a chiral propeller structure of pyridines around the central metal along with its concerted interaction with an atropisomer of biphenyl, made a threefold spiral structure.

scholarly journals A liquid culture system for murine megakaryocyte progenitor cells

Blood ◽  
1982 ◽  
Vol 59 (2) ◽  
pp. 250-257
Author(s):  
T Nagasawa ◽  
M Nakazawa ◽  
T Abe
Keyword(s):  
Progenitor Cells ◽  
Conditioned Medium ◽  
Culture System ◽  
Liquid Culture ◽  
Culture Medium ◽  
Pokeweed Mitogen ◽  
Plasma Clot ◽  
Liquid Culture System ◽  
Cell Conditioned Medium ◽  
Number Of Cells

A liquid culture system is described for murine megakaryocyte progenitor cells (CFU-M) in the presence of pokeweed-mitogen-stimulated spleen-cell conditioned medium. There were dose-related responses between the number of CFU-M developed and the number of cells cultured and the dosage of conditioned medium in this liquid culture system. Murine CFU-M were abundantly cloned in this system an the plating efficiency was similar in comparison with that in a plasma clot system. The acetylcholinesterase-positive colonies (more than 4 acetylcholinesterase-positive cells) were clearly seen on day 3 of culture, and they reached a maximum (60.5 +/- 10.7/2 x 10(5) cells) on day 7 of culture. Ultrastructural analyses of megakaryocytic maturation in this system showed that a few megakaryocytes produced platelets that were released in the culture medium on day 5 of culture. This liquid culture system is suitable for the study of the dynamic process of the megakaryocyte-platelet system.

Orthogonal spiral structures for energy harvesting applications: Theoretical and experimental analysis

2018 ◽  
Vol 29 (9) ◽  
pp. 1900-1912 ◽  
Author(s):  
Auteliano Antunes Dos Santos ◽  
Jared D. Hobeck ◽  
Daniel J Inman
Keyword(s):  
Energy Harvesting ◽  
Cantilever Beam ◽  
Microelectromechanical Systems ◽  
Spiral Structure ◽  
Structure Design ◽  
Lumped Parameter Model ◽  
Archimedean Spiral ◽  
Reduced Frequency ◽  
Harvesting Systems ◽  
Spiral Structures

The capture of energy from vibration of mechanical systems has been extensively studied with the goal of providing power for various microelectromechanical systems. The traditional cantilever beam approach was used as a starting design for more complex, multiple-beam structures like zigzag or spiral geometries. This work presents the orthogonal spiral structure, an alternative compact periodic structure for reduced frequency energy harvesting. The proposed orthogonal spiral structure design is inspired by a combination of zigzag and Archimedean spiral geometries. The orthogonal spiral structure takes advantage of a simple cantilever beam-based design as with the zigzag, but includes the compact concentric-type design of an Archimedean spiral. First, the fundamental frequency is estimated using a lumped parameter model for the substrate beam and the results are compared with experimental results for two different sizes of orthogonal spiral structures. Then, the same model is updated to include a layer of piezoelectric material and used to identify the strain nodes along each beam obtained from the first mode shape. Finally, electromechanical modeling is developed allowing for the evaluation of the energy harvested from base excitations. The results show that the orthogonal spiral structure can be used as an alternative to current energy harvesting systems for micro scale applications.

scholarly journals Magnetic Fields and Spiral Structure

1983 ◽  
Vol 100 ◽  
pp. 159-160 ◽  
Author(s):  
R. Beck
Keyword(s):  
Star Formation ◽  
Magnetic Fields ◽  
Milky Way ◽  
Spiral Structure ◽  
Radio Continuum ◽  
Continuum Emission ◽  
Radio Telescopes ◽  
Evolution Of Galaxies ◽  
Structure Strength ◽  
Spiral Structures

Interstellar magnetic fields are known to be a constraint for star formation, but their influence on the formation of spiral structures and the evolution of galaxies is generally neglected. Structure, strength and degree of uniformity of interstellar magnetic fields can be determined by measuring the linearly polarised radio continuum emission at several frequencies (e.g. Beck, 1982). Results for 7 galaxies observed until now with the Effelsberg and Westerbork radio telescopes are given in the table. The Milky Way is also included for comparison.

scholarly journals FORMATION OF TRYPSIN FROM TRYPSINOGEN BY AN ENZYME PRODUCED BY A MOLD OF THE GENUS PENICILLIUM

1938 ◽  
Vol 21 (5) ◽  
pp. 601-620 ◽  
Author(s):  
M. Kunitz
Keyword(s):  
Temperature Coefficient ◽  
Acid Medium ◽  
Experimental Error ◽  
Protein Concentration ◽  
Liquid Culture ◽  
Culture Medium ◽  
Specific Activity ◽  
Crystalline Form ◽  
Liquid Culture Medium ◽  
Autocatalytic Activation

1. A powerful kinase which changes trypsinogen to trypsin was found to be present in the synthetic liquid culture medium of a mold of the genus Penicillium. 2. The concentration of kinase in the medium is increased gradually during the growth of the mold organism and continues to increase for some time even after the mold has ceased growing. 3. Mold kinase transforms trypsinogen to trypsin only in an acid medium. It differs thus from enterokinase and trypsin which activate trypsinogen best in a slightly alkaline medium. 4. The action of the mold kinase in the process of transformation of trypsinogen is that of a typical enzyme. The process follows the course of a catalytic unimolecular reaction, the rate of formation of a definite amount of trypsin being proportional to the concentration of kinase added. The ultimate amount of trypsin formed, however, is independent of the concentration of kinase used. 5. The formation of trypsin from trypsinogen by mold kinase is not accompanied by any measurable loss of protein. 6. The temperature coefficient of formation of trypsin from trypsinogen by mold kinase varies from Q5–15 = 1.70 to Q25–30 = 1.25 with a corresponding variation in the value of µ from 8100 to 4250. 7. Trypsin formed from trypsinogen by means of mold kinase is identical in crystalline form with the crystalline trypsin obtained by spontaneous autocatalytic activation of trypsinogen at pH 8.0. The two products have within the experimental error the same solubility and specific activity. A solution saturated with the crystals of either one of the trypsin preparations does not show any increase in protein concentration or activity when crystals of the other trypsin preparation are added. 8. The Penicillium mold kinase has a slight activating effect on chymo-trypsinogen the rate being only 1–2 per cent of that of trypsinogen. The activation, as in the case of trypsinogen, takes place only in an acid medium. 9. Mold kinase is rapidly destroyed when brought to pH 6.5 or higher, and also when heated to 70°C. In the temperature range of 50–60°C. the inactivation of kinase follows a unimolecular course with a temperature coefficient of Q10 = 12.1 and µ = 53,500. The molecular weight of mold kinase, as determined by diffusion, is 40,000.

Detection Method for Histamine-Producing, Dairy-Related Bacteria using Diamine Oxidase and Leucocrystal Violet

1989 ◽  
Vol 52 (2) ◽  
pp. 105-108 ◽  
Author(s):  
SUSAN S. SUMNER ◽  
STEVE L. TAYLOR
Keyword(s):  
Hydrogen Peroxide ◽  
Liquid Culture ◽  
Diamine Oxidase ◽  
Culture Medium ◽  
Detection Method ◽  
Enzyme System ◽  
Color Formation ◽  
Liquid Culture Medium ◽  
Leucocrystal Violet ◽  
Purple Color

A detection method for histamine-producing, dairy-related bacteria was developed that involves a two-step sequential enzyme system. First, isolated bacteria are incubated in MRS broth or trypticase soy broth fortified with histidine. The histamine formed during this incubation period is reacted with diamine oxidase, which catalyzes the oxidation of histamine to form imidazole acetaldehyde, ammonia, and hydrogen peroxide. The hydrogen peroxide is then detected by the formation of crystal violet from the leuco base in the presence of horseradish peroxidase. Liquid culture medium containing bacteria that produce greater than 1200 nmole histamine per ml will develop a positive purple color. Cultures containing bacteria that produce little or no histamine will not develop a purple color. Other amines often found in cheese, such as tyramine, cadaverine, or putrescine, will not interfere with the color formation.

A PROCEDURE FOR RAPID RECOVERY OF AFLATOXINS FROM CHEESE AND OTHER FOODS1

1971 ◽  
Vol 34 (3) ◽  
pp. 119-123 ◽  
Author(s):  
C. N. Shih ◽  
E. H. Marth
Keyword(s):  
Liquid Culture ◽  
Culture Medium ◽  
Peanut Butter ◽  
Corn Meal ◽  
Water Fraction ◽  
Food Residue ◽  
Liquid Culture Medium ◽  
Chloroform Layer ◽  
Sequential Addition ◽  
Chloroform Methanol

A rapid and efficient method has been developed to recover aflatoxin from cheese and other foods. The procedure involves: (a) blending the sample with a mixture of chloroform, methanol, and water (solvents are used in such proportions that a miscible (monophasic) system is formed, (b) adding more chloroform and water so the mixture becomes biphasic, (c) filtering to remove the food residue, (d) separating the lower chloroform layer which contains virtually all of the aflatoxin, and (e) purification, if necessary, of the material in step (d) after it has been concentrated. Purification is achieved by sequential addition of methanol, water, and hexane; recovery of tho methanol-water fraction; and extraction of aflatoxins from it with chloroform. Purification can be eliminated if the substrate contains little or no lipid or pigment which, if present, interfere with thin-layer chromaographic analysis. Extraction can be done in approximately 35 min and purification in approximately 20 min. When aflatoxins were added to various substrates, the method recovered 92–98% B1 and 96–100% G1 from rice; 95–96% B1 and 90–95% G1 from peanut butter; 93–94% B1 and 92–98% G1 from Cheddar cheese; 100% B1 and G1 from corn meal; 91–100% B1, 91–100% B2, 90–96% G1, and 92–100% G2 from brick cheese; and 97–100% B1, 95–100% B2, 92–100% G1, and 98–100% G2 from a liquid culture medium.

Rapid analysis of GBSS1 and Vinv genes expressed in potato tubers using microtubers produced in liquid culture medium

2020 ◽  
Vol 39 (11) ◽  
pp. 1415-1424
Author(s):  
Yuhya Wakasa ◽  
Atsushi Kasai ◽  
Muneo Yamazaki ◽  
Yutaka Tabei ◽  
Mutsuo Tsuyama ◽  
...  
Keyword(s):  
Liquid Culture ◽  
Culture Medium ◽  
Rapid Analysis ◽  
Potato Tubers ◽  
Liquid Culture Medium
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