In situ colonization of polyvinyl chloride, brass, and copper by Legionella pneumophila

1992 ◽  
Vol 38 (4) ◽  
pp. 328-330 ◽  
Author(s):  
Gregory Bezanson ◽  
Susan Burbridge ◽  
David Haldane ◽  
Thomas Marrie
Keyword(s):  
Key Words ◽  
Polyvinyl Chloride ◽  
Legionella Pneumophila ◽  
Potable Water ◽  
Sampling Device ◽  
Plumbing Systems ◽  
Materials Used ◽  
Colonization Rates

A sampling device (Robbins device) was used to expose brass, copper, and polyvinyl chloride plugs to potable water contaminated by Legionella pneumophila serogroup 1. Plugs were removed at approximately 1-week intervals and cultured. The colonization rates were polyvinyl chloride, 70; copper, 31; and brass, 25%. Quantitative cultures revealed that polyvinyl chloride was most heavily colonized, whereas brass was least colonized. We conclude that materials used in plumbing systems are readily colonized by Legionella and that the Robbins device provides a means for testing such materials in an in situ setting. Key words: Legionella, colonization, plumbing materials.

Efficiency of diagnosis and treatment non-invasive and microinvasive sgamous cell cervical cancer

2020 ◽  
pp. 71-74
Author(s):  
M.M. Melnyk ◽  
◽  
S.V. Nespradko ◽  
I.V. Goncharuk ◽  
M.V. Marchenko ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Key Words ◽  
National Cancer Institute ◽  
Reproductive Function ◽  
Diagnosis And Treatment ◽  
Non Invasive ◽  
Corpus Uteri ◽  
Complex Program ◽  
Early Cervical Cancer

The objective: analyse the effectiveness of diagnosis and treatment for early cervical cancer. Materials and methods. Analysed 107 cases of women’s disease on CIN ІІІ, cancer in situ, they were on treatment in National cancer institute and Kyiv dictrict cancer dispensary from 2010 till 2015 years. Results. Diagnosed percent relapse CIN ІІІ, cancer in situ contain 4.57% uninvasive and invasive form – 0.94%. Conclusion. According diagnostic CIN ІІ and CIN ІІІ is recommended to do treatment conization and dynamic dispensary observation. Are making complex program of infection HPV16, 18. In appering of margins resection some elements of tumor after wider conization by forms of cancer in situ. Many of expansive burns in cervical glands, in making of reproductive function, going disease (nodel leiomyoma of corpus uteri etc). In perspective is accept the notion of looking after and screening research of considering infection HPV16, 18 on CIN І, CIN ІІ. Key words: cervical cancer, сancer in situ, CIN І–ІІІ, diagnostic, treatment, conization.

scholarly journals Effects of Infills in the Seismic Performance of an RC Factory Building in Pakistan

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 276
Author(s):  
Nisar Ali Khan ◽  
Giorgio Monti ◽  
Camillo Nuti ◽  
Marco Vailati
Keyword(s):  
Numerical Model ◽  
Construction Materials ◽  
Building Codes ◽  
Construction Technique ◽  
Infill Walls ◽  
Mortar Strength ◽  
Materials Used ◽  
Seismic Response Of Buildings

Infilled reinforced concrete (IRC) frames are a very common construction typology, not only in developing countries such as Pakistan but also in southern Europe and Western countries, due to their ease of construction and less technical skills required for the construction. Their performance during past earthquakes has been in some cases satisfactory and in other cases inadequate. Significant effort has been made among researchers to improve such performance, but few have highlighted the influence of construction materials used in the infill walls. In some building codes, infills are still considered as non-structural elements, both in the design of new buildings and, sometimes, in the assessment of existing buildings. This is mainly due to some difficulties in modeling their mechanical behavior and also the large variety of typologies, which are difficult to categorize. Some building codes, for example, Eurocode, already address the influence of infill walls in design, but there is still a lack of homogeneity among different codes. For example, the Pakistan building code (PBC) does not address infills, despite being a common construction technique in the country. Past earthquake survey records show that construction materials and infill types significantly affect the seismic response of buildings, thus highlighting the importance of investigating such parameters. This is the object of this work, where a numerical model for infill walls is introduced, which aims at predicting their failure mode, as a function of some essential parameters, such as the friction coefficient between mortar and brick surface and mortar strength, usually disregarded in previous models. A comprehensive case study is presented of a three-story IRC frame located in the city of Mirpur, Pakistan, hit by an earthquake of magnitude 5.9 on 24 September 2019. The results obtained from the numerical model show good agreement with the damage patterns observed in situ, thus highlighting the importance of correctly modeling the infill walls when seismically designing or assessing Pakistani buildings that make use of this technology.

Chromosome mobilization of Legionella pneumophila with RK2::Mu and Tn5-Mob

1992 ◽  
Vol 38 (7) ◽  
pp. 664-671 ◽  
Author(s):  
Clifford S. Mintz ◽  
Chang Hua Zou
Keyword(s):  
Genetic Mapping ◽  
Key Words ◽  
Legionella Pneumophila ◽  
Transposon Tn5 ◽  
Helper Plasmid ◽  
Chromosome Transfer ◽  
Chromosomal Markers

RK2::Mu plasmids and transposon Tn5-Mob were used to mobilize the Legionella pneumophila chromosome. Plate matings between L. pneumophila donors that contained RK2::Mu plasmids and auxotrophic recipients yielded recombinants at fequencies ranging from 10−6 to 10−7 per recipient for the markers tested. The presence of a Mu insertion in the chromosome of donors that harbored RK2::Mu plasmids increased the frequency of chromosome transfer of certain selected markers as compared with strains that contained RK2::Mu alone. Cotransfer experiments with Mu-containing donors and a thymidine and tryptophan auxotroph failed to reveal any linkage between the thy and trp loci in L. pneumophila. A strain that contained a chromosomal Tn5-Mob insertion and helper plasmid pRK24.4 transferred chromosomal markers at frequencies of 10−7 per recipient. These findings suggest that RK2::Mu plasmids and Tn5-Mob may be useful for genetic mapping experiments with L. pneumophila. Key words: Legionella pneumophila, chromosome transfer, Tn5-Mob, RK2::Mu.

In situ estimation of the coefficient of consolidation in clays

1990 ◽  
Vol 27 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Mohammed G. Kabir ◽  
Alan J. Lutenegger
Keyword(s):  
Key Words ◽  
Pore Pressure ◽  
Reference Values ◽  
Time Factors ◽  
In Situ Tests ◽  
Coefficient Of Consolidation ◽  
Oedometer Test ◽  
Undisturbed Samples ◽  
Oedometer Tests

An investigation was conducted to demonstrate the applicability of cylindrical piezocone and flat piezoblade tests for providing reliable estimates of the coefficient of consolidation in clays. Coefficients of consolidation were calculated from piezocone dissipation tests for different degrees of consolidation using theoretical time factors to provide a comparison with laboratory oedometer tests. Three techniques were developed to calculate the coefficient of consolidation from piezoblade dissipation tests. Results from in situ pore pressure dissipation tests were compared with laboratory oedometer tests performed on undisturbed samples oriented in both the vertical and horizontal directions, to provide reference values of cv and ch. The results of investigations conducted at several clay sites are presented. Key words: in situ tests, piezocone, piezoblade, coefficient of consolidation, oedometer test, clays.

How the parasitic bacterium Legionella pneumophila modifies its phagosome and transforms it into rough ER: implications for conversion of plasma membrane to the ER membrane

2001 ◽  
Vol 114 (24) ◽  
pp. 4637-4650 ◽  
Author(s):  
Lewis G. Tilney ◽  
Omar S. Harb ◽  
Patricia S. Connelly ◽  
Camenzind G. Robinson ◽  
Craig R. Roy
Keyword(s):  
Legionella Pneumophila ◽  
Mitochondrial Membranes ◽  
Macrophage Infection ◽  
Thin Sections ◽  
Stage Process ◽  
Legionnaires Disease ◽  
Rough Er ◽  
Membrane Changes ◽  
Phagosomal Membrane

Within five minutes of macrophage infection by Legionella pneumophila, the bacterium responsible for Legionnaires’ disease, elements of the rough endoplasmic reticulum (RER) and mitochondria attach to the surface of the bacteria-enclosed phagosome. Connecting these abutting membranes are tiny hairs, which are frequently periodic like the rungs of a ladder. These connections are stable and of high affinity - phagosomes from infected macrophages remain connected to the ER and mitochondria (as they were in situ) even after infected macrophages are homogenized. Thin sections through the plasma and phagosomal membranes show that the phagosomal membrane is thicker (72±2 Å) than the ER and mitochondrial membranes (60±2 Å), presumably owing to the lack of cholesterol, sphingolipids and glycolipids in the ER. Interestingly, within 15 minutes of infection, the phagosomal membrane changes thickness to resemble that of the attached ER vesicles. Only later (e.g. after six hours) does the ER-phagosome association become less frequent. Instead ribosomes stud the former phagosomal membrane and L. pneumophila reside directly in the rough ER. Examination of phagosomes of various L. pneumophila mutants suggests that this membrane conversion is a four-stage process used by L. pneumophila to establish itself in the RER and to survive intracellularly. But what is particularly interesting is that L. pneumophila is exploiting a poorly characterized naturally occuring cellular process.

scholarly journals The presence and absence of periplasmic rings in bacterial flagellar motors correlates with stator type

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Mohammed Kaplan ◽  
Debnath Ghosal ◽  
Poorna Subramanian ◽  
Catherine M Oikonomou ◽  
Andreas Kjaer ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Pathogenic Bacteria ◽  
Bioinformatics Analysis ◽  
Cell Envelope ◽  
Shewanella Oneidensis ◽  
Flagellar Motor ◽  
Flagellar Motors ◽  
A Cell ◽  
Animal Hosts

The bacterial flagellar motor, a cell-envelope-embedded macromolecular machine that functions as a cellular propeller, exhibits significant structural variability between species. Different torque-generating stator modules allow motors to operate in different pH, salt or viscosity levels. How such diversity evolved is unknown. Here, we use electron cryo-tomography to determine the in situ macromolecular structures of three Gammaproteobacteria motors: Legionella pneumophila, Pseudomonas aeruginosa, and Shewanella oneidensis, providing the first views of intact motors with dual stator systems. Complementing our imaging with bioinformatics analysis, we find a correlation between the motor’s stator system and its structural elaboration. Motors with a single H+-driven stator have only the core periplasmic P- and L-rings; those with dual H+-driven stators have an elaborated P-ring; and motors with Na+ or Na+/H+-driven stators have both their P- and L-rings embellished. Our results suggest an evolution of structural elaboration that may have enabled pathogenic bacteria to colonize higher-viscosity environments in animal hosts.

scholarly journals Susceptibility of earth-based construction materials to fungal proliferation: laboratory and in situ assessment

2019 ◽  
Vol 3 ◽  
pp. 140-149 ◽  
Author(s):  
Alexis Simons ◽  
Alexandra Bertron ◽  
Christophe Roux ◽  
Aurélie Laborel-Préneron ◽  
Jean-Emmanuel Aubert ◽  
...  
Keyword(s):  
Air Quality ◽  
Manufacturing Process ◽  
Building Materials ◽  
Construction Materials ◽  
Microbial Density ◽  
Microbial Proliferation ◽  
Materials Used ◽  
Ecological Construction ◽  
The Impact

The impact of building materials on the environment and the health of occupants is nowadays a priority issue. Ecological construction materials such as earthen materials are currently experiencing a regain of interest due to both ecological and economic factors. The microbial proliferation on indoor materials can induce a deterioration of the building air quality and lead to an increase of health risks for the occupants. The issue of indoor air quality raises questions about the use of earthen building materials and their possible susceptibility to fungal development. The microflora of earthen materials and their ability to grow on such support are indeed poorly studied. This study focused on the quantification of both bacterial and fungal microflora along the manufacturing process. The impact of extreme humidity, simulating a hydric accident, on microflora development was analyzed on the surface and inside earthen bricks. The initial microflora of these materials was dramatically reduced during the manufacturing process, especially after heat treatment for drying. Proliferation of remaining microorganisms was only observed under high humidity condition, in particular for earthen materials with vegetal aggregates. Moreover, in situ samplings were performed on naturally dried earthen materials used in buildings. The characterization of the microbial density revealed a higher microbial density than on manufactured specimens, while microbial concentration and detected taxa seemed mainly related to the room use and building history. These results provide a better understanding of microbial proliferation on these materials.

scholarly journals ELECTROCHEMICAL OXIDATION OF ETHANOL USING Ni-Co-PVC COMPOSITE ELECTRODE

2011 ◽  
Vol 11 (1) ◽  
pp. 75-84 ◽  
Author(s):  
Riyanto Riyanto ◽  
Mohamed Rozali Othman ◽  
Jumat Salimon
Keyword(s):  
Polyvinyl Chloride ◽  
Electrochemical Behavior ◽  
Morphological Characteristics ◽  
Redox System ◽  
Electrochemical Technique ◽  
Metal Foil ◽  
Composite Electrodes ◽  
Nickel Metal ◽  
Nickel Cobalt

The morphological characteristics and electrochemical behavior of nickel metal foil (Ni), nickel-polyvinyl chloride (Ni-PVC) and nickel-cobalt-polyvinyl chloride (Ni-Co-PVC) electrodes in alkaline solution has been investigated. The morphological characteristics of the electrode surface were studied using SEM and EDS, while the electrochemical behavior of the electrodes was studied using cyclic voltammetry (CV). It was found that composite electrodes (Ni-PVC and Ni-Co-PVC) have a porous, irregular and rough surface. In situ studies using electrochemical technique using those three electrodes exhibited electrochemical activity for redox system, as well as selectivity in the electrooxidation of ethanol to acetic acid. The studies also found that an electrokinetics and electrocatalytic activity behaviors of the electrodes prepared were Ni metal foil

Efficacy of thermal treatment and copper-silver ionization for controlling Legionella pneumophila in high-volume hot water plumbing systems in hospitals

1997 ◽  
Vol 25 (6) ◽  
pp. 452-457 ◽  
Author(s):  
Sue Miuetzner ◽  
Robert C. Schwille, ◽  
Adrianne Farley ◽  
Ellen R. Wald ◽  
John H. Ge ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Legionella Pneumophila ◽  
High Volume ◽  
Hot Water ◽  
Plumbing Systems

A Hand-Operated Suction Sampler for the Collection of Subtidal Organisms

1977 ◽  
Vol 34 (7) ◽  
pp. 1031-1034 ◽  
Author(s):  
C. Tanner ◽  
M. W. Hawkes ◽  
P. A. Lebednik ◽  
E. Duffield
Keyword(s):  
Key Words ◽  
Benthic Algae ◽  
Benthic Organisms ◽  
Sampling Device ◽  
Scuba Divers ◽  
Suction Sampler

A hand-operated suction sampler is described for use by SCUBA divers. The sampler is simple in construction and compact in size, and it provides a means by which diminutive benthic algae, invertebrates, or fish may be collected. Key words: algae, benthic organisms, sampling device, SCUBA, suction sampler

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