Toward Creating Life in a Test-Tube

2003 ◽  
pp. 257-272
Author(s):  
Martino Rizzotti
Keyword(s):  
Test Tube

In Vitro Studies on the Mechanism of the Antifibrino-lytic Action of E-Aminocaproic Acid (EACA)

1968 ◽  
Vol 19 (03/04) ◽  
pp. 584-592 ◽  
Author(s):  
Hanna Lukasiewicz ◽  
S Niewiarowski
Keyword(s):  
Aminocaproic Acid ◽  
Test Tube ◽  
In Vitro Studies ◽  
Lytic Action ◽  
Human Plasminogen ◽  
Experimental Findings ◽  
Fibrin Clots

Summary and Conclusion1. It has been found that EACA does not inhibit activation of human plasminogen into plasmin by SK and UK in a concentration of 5 × 10–2 M. The activation of bovine plasminogen by SK and UK is inhibited by this concentration of EACA but not by a lower one.2. EACA in concentrations of 1,5 × 10–1 – 10–4 M does not inhibit casein proteolysis by plasmin. The proteolysis of fibrinogen and fibrin measured by the release of TCA soluble tyrosine is inhibited by EACA in concentrations of 1,5 × 10–1 – 10–2 M.3. The lysis of non-stabilized clots by plasmin measured in a test tube was inhibited by an EACA concentration of 5 × 10–3 – 5 × 10–4 M. The lysis of stabilized clots by plasmin was inhibited by an EACA concentration of 10–5 M.4. On the basis of experimental findings and data given in literature the authors postulate that the mechanism of the antifibrinolytic effects of EACA consists mainly in a modification of plasmin action on fibrin. These effects are dependent on the structure of the fibrin clots.

New Caledonia: Pacific Test Tube

1945 ◽  
Vol 14 (24) ◽  
pp. 355-357
Author(s):  
Lawrence Lader
Keyword(s):  
New Caledonia ◽  
Test Tube

Design and Analysis of the Novel Test Tube Magnet for Portable NMR Device

PIERS Online ◽  
2007 ◽  
Vol 3 (6) ◽  
pp. 900-904
Author(s):  
Jizhong Chen ◽  
Yiming Zhang ◽  
Jijun Xiao
Keyword(s):  
Test Tube ◽  
The Novel ◽  
Portable Nmr

scholarly journals Investigation of the Effectiveness of Disinfectants Used in Meat-Processing Facilities to Control Clostridium sporogenes and Clostridioides difficile Spores

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1436
Author(s):  
Siobhán McSharry ◽  
Leonard Koolman ◽  
Paul Whyte ◽  
Declan Bolton
Keyword(s):  
Test Tube ◽  
Meat Industry ◽  
Meat Processing ◽  
Clostridium Sporogenes ◽  
Safety Issues ◽  
Clostridioides Difficile ◽  
Plant Environment ◽  
D Values ◽  
Sulphamic Acid ◽  
Spore Forming Bacteria

Spore-forming bacteria are a major concern for the food industry as they cause both spoilage and food safety issues. Moreover, as they are more resistant than vegetative cells, their removal from the food processing environment may be difficult to achieve. This study investigated the efficacy of the ten most commonly used disinfectant agents (assigned 1–10), used at the recommended concentrations in the meat industry, for their ability to eliminate Clostridium sporogenes and Clostridioides difficile spores. Test-tube based suspension assays suggested that disinfectants 2 (10% v/v preparation of a mixture of hydrogen peroxide (10–30%), acetic acid (1–10%) and peracetic acid (1–10%)), 7 (4% w/v preparation of a mixture of peroxymonosulphate (30–50%), sulphamic acid (1–10%) and troclosene sodium (1–10%)) and 10 (2% v/v preparation of a mixture of glutaraldehyde (10–30%), benzalkonium chloride (1–10%)) were the most effective formulations. D-values for these ranged from 2.1 to 8.4 min at 20 °C for the target spores. Based on these findings, it is recommended that these disinfectants are used to control Clostridium spores in the meat plant environment.

scholarly journals Systematic heat transfer measurements in highly viscous binary fluids

2021 ◽  
Author(s):  
Ann-Christin Fleer ◽  
Markus Richter ◽  
Roland Span
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Volatile Component ◽  
Test Tube ◽  
Heat Fluxes ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Low Viscosity ◽  
The Heat Transfer Coefficient

AbstractInvestigations of flow boiling in highly viscous fluids show that heat transfer mechanisms in such fluids are different from those in fluids of low viscosity like refrigerants or water. To gain a better understanding, a modified standard apparatus was developed; it was specifically designed for fluids of high viscosity up to 1000 Pa∙s and enables heat transfer measurements with a single horizontal test tube over a wide range of heat fluxes. Here, we present measurements of the heat transfer coefficient at pool boiling conditions in highly viscous binary mixtures of three different polydimethylsiloxanes (PDMS) and n-pentane, which is the volatile component in the mixture. Systematic measurements were carried out to investigate pool boiling in mixtures with a focus on the temperature, the viscosity of the non-volatile component and the fraction of the volatile component on the heat transfer coefficient. Furthermore, copper test tubes with polished and sanded surfaces were used to evaluate the influence of the surface structure on the heat transfer coefficient. The results show that viscosity and composition of the mixture have the strongest effect on the heat transfer coefficient in highly viscous mixtures, whereby the viscosity of the mixture depends on the base viscosity of the used PDMS, on the concentration of n-pentane in the mixture, and on the temperature. For nucleate boiling, the influence of the surface structure of the test tube is less pronounced than observed in boiling experiments with pure fluids of low viscosity, but the relative enhancement of the heat transfer coefficient is still significant. In particular for mixtures with high concentrations of the volatile component and at high pool temperature, heat transfer coefficients increase with heat flux until they reach a maximum. At further increased heat fluxes the heat transfer coefficients decrease again. Observed temperature differences between heating surface and pool are much larger than for boiling fluids with low viscosity. Temperature differences up to 137 K (for a mixture containing 5% n-pentane by mass at a heat flux of 13.6 kW/m2) were measured.

Crystal Violet, an Electronic Model Substance for Rubber and Related Olefins

1951 ◽  
Vol 24 (1) ◽  
pp. 169-181 ◽  
Author(s):  
G. J. van Veersen
Keyword(s):  
Crystal Violet ◽  
Electronic Structures ◽  
Radical Reaction ◽  
Test Tube ◽  
Chemical Agent ◽  
Blue Color ◽  
Electronic Model ◽  
Model Substance ◽  
Model Substances ◽  
Polar Reaction

Abstract It is shown that triphenylmethyl dyes like crystal violet can be used as model substances for rubber and related olefins. Arguments are given in support of the assumption that agents which react with rubber and related olefins in a polar manner cause a reversible shift in color from blue to yellow with crystal violet, whereas a fading of the blue color of crystal violet (if alkaline or reducing agents are excluded) points to a radical reaction. Since the electronic structures of donor olefins and crystal violet are considered and not the molecular structure, as usually is done in the choice of a model substance, these dyes have been named electronic model substances. Though crystal violet, as an electronic model substance cannot be used for the study of the overall reactions, information can often be obtained concerning the first step in a reaction of rubber with a certain chemical agent by means of a simple test-tube reaction with crystal violet. It was pointed out that the π-electron availability at the non-methylated carbon atom of the double bond in rubber and at the nitrogen atoms in crystal violet is probably of the same order. As an application of crystal violet as an electronic model substance for rubber, a polar reaction between sulfur and rubber is suggested as the first step in vulcanization.

Edward Armand Guggenheim, 1901-1970

1971 ◽  
Vol 17 ◽  
pp. 303-326 ◽  
Keyword(s):  
Organic Synthesis ◽  
Small Volume ◽  
Test Tube ◽  
Cotton Cloth ◽  
Early Age ◽  
Cambridge University ◽  
Crystalline Product ◽  
Mathematical Sciences ◽  
One Year ◽  
Oliver Lodge

Edward Armand Guggenheim was born on 11 August 1901 in Manchester; he was the elder brother of a family of three. His father, Armand Guggenheim, was of Swiss nationality but became a naturalized British subject at the age of forty-six in 1906. He was the senior partner in E. Spinner & Co., importers of Indian cotton and exporters of cotton cloth, especially khaki, and during the years 1917-1923 was also the Swiss Consul in Manchester. Edward after attending Terra Nova School, Birkdale, Southport, proceeded at the age of fourteen with a Junior Scholarship to Charterhouse. At first he was on the classical side but he switched to the science side where he came under the influence of two outstanding mathematics teachers, C. O. Tuckey and Alfred Lodge who was the brother of the more famous Oliver Lodge. His high intellectual qualities developed rapidly at Charterhouse, where he gained a Senior Scholarship in 1917 and was top of the sixth form in mathematical sciences for the period 1918-1920. His strong character and desire for authority were recognized by his election to the Head of House during his last year at School. Edward’s father died at the early age of 63, but his mother lived much longer and was an admirable hostess to Edward’s friends. After declining an Exhibition in the previous year, Edward won a Scholarship from Charterhouse to Cambridge University at Gonville and Caius College in 1920. One year later he obtained a first-class mathematical tripos in Part 1 and in 1923 a first-class in the natural science tripos, Part 2, in chemistry. One imagines that his theoretical papers were outstanding, since his practical ability at that time appears not to have been exceptionally high, particularly in preparative organic chemistry. After completion of an organic synthesis, which should have given a crystalline product, he was holding a test-tube containing a small volume of a viscous tarry material. It is reported that he contrived to collide with a perambulating demonstrator and, with studied carelessness, allowed the only record of his work to slip through his fingers with consequent breakage of the test-tube.

scholarly journals Isolation and Characterization of Nitrate Reducing Bacteria for Conversion of Vegetable-Derived Nitrate to ‘Natural Nitrite’

2021 ◽  
Vol 1 (1) ◽  
pp. 11-23
Author(s):  
Arjun Bhusal ◽  
Peter M. Muriana
Keyword(s):  
Nitrate Reduction ◽  
High Performance ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Test Tube ◽  
Screening Assay ◽  
Isolation And Characterization ◽  
The Us ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria

In the US, sodium nitrate is used as a preservative and curing agent in processed meats and is therefore a regulated ingredient. Nitrate reducing bacteria (NRB) can convert vegetable nitrate into nitrite allowing green/clean label status in the US as per the USDA-FSIS definition of ‘natural nitrite’. The current ‘in-liquid’ test tube assay for detecting nitrite is not suitable for screening mixtures of bacteria nor is commercial nitrate broth suitable for growth of many Gram (+) bacteria. M17 broth was therefore used to develop M17-nitrate broth to be inclusive of Gram (+) bacteria. An ‘on-agar’ colony-screening assay was developed to detect the conversion of nitrate to nitrite on agar plates and could detect one NRB+ colony among ~300–500 colonies on a single plate. Samples that might have NRB were spread-plated on M17 agar plates, sandwiched with nitrate agar, and after incubation followed with sequential agar overlays containing the reagents used in the nitrate reduction assay; the appearance of red color zones above colonies indicated the presence of nitrite. NRB derived from various samples were confirmed for nitrate conversion and both nitrate and nitrite were quantified by C8 reversed-phase (RP) ion-pairing high performance liquid chromatography (HPLC) analysis (1 ppm limit of detection). Staphylococcus carnosus, a strain commonly used for nitrate reduction, was able to convert 1100 ppm M17-nitrate broth to 917 ppm nitrite. Staphylococcus caprae and Panteoa agglomerans, NRB isolated using the M17-nitrate agar assay, were also able to ferment the same broth to 916 ppm and 867 ppm nitrite, respectively. This is the first report of an on-agar colony screening assay for the detection and isolation of nitrite reducing bacteria allowing NRB to be readily isolated. This may allow for the identification of new bacteria that may have a more efficient process to generate nitrite, and possibly concomitant with production of additional natural antimicrobials, as vegetable nitrite becomes more widely used to prevent spore germination.

III. On a new substance occurring in the urine of a patient with mollities ossium

1848 ◽  
Vol 138 ◽  
pp. 55-62 ◽  
Keyword(s):  
Nitric Acid ◽  
Specific Gravity ◽  
Test Tube ◽  
High Specific Gravity ◽  
Solid Substance ◽  
Semi Solid ◽  
Very High

On the 1st of November 1845 I received from Dr. Watson the following note, with a test tube containing a thick, yellow, semi-solid substance:—“The tube contains urine of very high specific gravity; when boiled it becomes highly opake; on the addition of nitric acid it effervesces, assumes a reddish hue, becomes quite clear, but, as it cools, assumes the consistence and appearance which you see: heat reliquifies it. What is it ?” A few hours afterwards a specimen of the same urine, passed by a grocer forty-seven years of age, who had been out of health for thirteen months, was sent to me by Dr. MacIntyre. He being in attendance on the case with Dr. Watson, had two days previously first observed the peculiar reactions of the urine.

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