scholarly journals Effect of Bacteria Inoculums on Compressive Strength

2021 ◽  
Vol 8 (2) ◽  
pp. 59-63
Author(s):  
Pooja Bandekar ◽  
Sandhay Basavaraj ◽  
Prakash Mallappa Munnoli ◽  
Jyoti Gupta ◽  
Geeta Shetteppanavar ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Cement Mortar ◽  
Culture Collection ◽  
Self Healing ◽  
Cement Concrete ◽  
Calcite Precipitation ◽  
Chain Reaction ◽  
Colony Forming Units ◽  
Polymerase Chain ◽  
Strength And Durability

The use of bio-concrete is increasing in the present day context and researchers are working on strength and durability characteristics of concrete using bacteria species which have shown calcite precipitation. Three different species of bacteria namely P. Fluorescence, B. Pumilis and B. Subliis that have calcite precipitation properties have been investigated in this study. The investigations were carried first on cement mortar (CM) cubes using these three bacteria species suspension of 20%; 40% and 60% having colony forming units P. Fluorescence (108 CFU/ml), B. Pumilis (106 CFU/ml) and B. Subtilis (108 CFU/ml) respectively. The 40% suspension in all the three cases has shown increased compressive strength as compared to 20% and 60%. The compressive strength measured showed increase (CS) of 18%; 12% for P. Fluorescence; B. Subtilis and decrease of 35% with B. Pumilis respectively. B. Subtilis with optimized 40% suspension having CFU 10x108/ml showed 4.32% ; 5.56%; and 3.81% increase in CS of CC cubes with 3 days; 7 days and 28 days respectively and 5.92% overall increase in CS of CC cubes as compared to the 3 days CS of control cube. ABBREVIATIONSSDW: Sterile Distilled Water; SHC: Self-Healing Concrete; PCR: Polymerase Chain Reaction; BC: Bacterial Concrete; CP: Calcite precipitation; CS: Compressive Strength; CC: Cement Concrete; CM: Cement Mortar; MTCC: Microbial Type Culture Collection; CFU: Colony Forming Unit/ml

Clonal analysis of deletions on chromosome 20q and JAK2-V617F in MPD suggests that del20q acts independently and is not one of the predisposing mutations for JAK2-V617F

Blood ◽  
2009 ◽  
Vol 113 (9) ◽  
pp. 2022-2027 ◽  
Author(s):  
Franz X. Schaub ◽  
Roland Jäger ◽  
Renate Looser ◽  
Hui Hao-Shen ◽  
Sylvie Hermouet ◽  
...  
Keyword(s):  
Temporal Order ◽  
Jak2 V617f ◽  
Myeloproliferative Disorders ◽  
Genetic Alterations ◽  
Parental Origin ◽  
Wild Type ◽  
Chain Reaction ◽  
Colony Forming Units ◽  
Opposite Order ◽  
Polymerase Chain

We developed a real-time copy number polymerase chain reaction assay for deletions on chromosome 20q (del20q), screened peripheral blood granulocytes from 664 patients with myeloproliferative disorders, and identified 19 patients with del20q (2.9%), of which 14 (74%) were also positive for JAK2-V617F. To examine the temporal relationship between the occurrence of del20q and JAK2-V617F, we performed colony assays in methylcellulose, picked individual burst-forming units–erythroid (BFU-E) and colony-forming units–granulocyte (CFU-G) colonies, and genotyped each colony individually for del20q and JAK2-V617F. In 2 of 9 patients, we found that some colonies with del20q carried only wild-type JAK2, whereas other del20q colonies were JAK2-V617F positive, indicating that del20q occurred before the acquisition of JAK2-V617F. However, in colonies from 3 of 9 patients, we observed the opposite order of events. The lack of a strict temporal order of occurrence makes it doubtful that del20q represents a predisposing event for JAK2-V617F. In 2 patients with JAK2-V617F and 1 patient with MPL-W515L, microsatellite analysis revealed that del20q affected chromosomes of different parental origin and/or 9pLOH occurred at least twice. The fact that rare somatic events, such as del20q or 9pLOH, occurred more than once in subclones from the same patients suggests that the myeloproliferative disorder clone carries a predisposition to acquiring such genetic alterations.

Influence of Particle Size Distribution of Fly Ash on Compressive Strength and Durability of Portland Cement Concrete

2011 ◽  
Vol 685 ◽  
pp. 211-215
Author(s):  
Jian Ping Zhu ◽  
Qi Lei Guo ◽  
Dong Xu Li ◽  
Cun Jun Li
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Power Plants ◽  
Reference Sample ◽  
Chloride Penetration ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Strength And Durability ◽  
Different Content ◽  
Better Than

The Present Research Investigates the Compressive and Durable Properties of Concretes with Fly Ash (FA), a by-Product of Coal-Fired Power Plants. for this Purpose, a Reference Sample and Twenty-one Concretes Containing FA Were Tested. the FA Was Sieved to 200, 300, and 400 Mesh. then FA Was Mixed into Concrete with Different Content. Compressive Strength at 7 and 28 Days, and Chloride Penetration Properties Were Measured. it Is Concluded that FA Can Be Used in the Production of Concrete. in Addition, the FA Concretes Present Satisfactory Physical Properties. when Proper Amount of FA Were Added the Concrete Properties Can Be Better than the Blank one.

Influences of Initial Curing Conditions on the Microstructure of Fly Ash Cement System

2010 ◽  
Vol 168-170 ◽  
pp. 532-536 ◽  
Author(s):  
Guo Li ◽  
En Li Lu ◽  
Peng Wang ◽  
Ou Geng ◽  
Yong Sheng Ji
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Cement Mortar ◽  
Early Age ◽  
Concrete Durability ◽  
Cement Concrete ◽  
Hydration Degree ◽  
Curing Conditions ◽  
Cement System ◽  
C 30

In order to study the influences of initial curing conditions on fly ash (FA) cement concrete durability, fly ash cement samples with 30% replacement ratio were fabricated and cured in water at 10°C, 20°C, 30°Cand 40°C for 3d, 7d, 14d and 28d respectively. Hydration degrees of fly ash at early age were measured using the selective dissolve method. Correspondingly the pore structure and morphology of FA-cement mortar and compared cement mortar were studied by using MIP and SEM methods. Then early age compressive strengths of FA-cement concrete and compared normal cement concrete were tested. Experimental results show that initial curing temperatures and ages are important factors to fly ash early age hydration degree, FA-cement system microstructure, morphology and early age compressive strength etc. High curing temperatures and longer curing time can lead higher fly ash hydration degree, and then higher compressive strength of FA-cement concrete, and make the micro-structures of fly ash-cement system denser.

scholarly journals Compressive strength of bacterial concrete by varying concentrations of E.Coli and JC3 bacteria for Self-Healing Concrete

2019 ◽  
Vol 9 (1) ◽  
pp. 3659-3661
Keyword(s):  
Compressive Strength ◽  
Bacillus Subtilis ◽  
Cell Concentration ◽  
Self Healing ◽  
E Coli ◽  
Strength And Durability ◽  
Bacterial Concrete

This paper focuses on how the bacterium produces calcite to repair cracks and thereby increases the strength and durability of the concrete. The bacterial concrete can be made by embedding bacteria in the concrete to make it constantly precipitate calcite. Bacillus E Coli and Bacillus Subtilis JC3 are used for this purpose. Bacillus E coli and Bacillus Subtilis JC3 induced at cell concentration 10^5 cells/ml improves properties of concrete. This paper campaigns for the induction of bacteria in concrete for the promotion of self-healing cracks.

scholarly journals Detection of pathogenicYersinia enterocoliticausing the multiplex polymerase chain reaction

1996 ◽  
Vol 117 (1) ◽  
pp. 59-67 ◽  
Author(s):  
N. Harnett ◽  
Y. P. Lin ◽  
C. Krishnan
Keyword(s):  
Polymerase Chain Reaction ◽  
Multiplex Polymerase Chain Reaction ◽  
Oligonucleotide Probes ◽  
Chain Reaction ◽  
Base Pairs ◽  
Single Colony ◽  
Colony Forming Units ◽  
The Family ◽  
Stool Specimens ◽  
Polymerase Chain

SummaryA multiplex polymerase chain reaction (PCR) was developed to detect the presence of theail, yst, andvirFgenes ofYersinia enterocoliticasimultaneously, quickly and accurately. The amplified fragment sizes were 356 base-pairs (bp) for theailgene, 134 bp for theystgene, and 231 bp for thevirFgene. The specificity of the amplified products was confirmed by hybridization with digoxigenin-labelled oligonucleotide probes. Amplification was successful whether the template was derived from a single colony of bacteria, aliquots of boiled bacterial suspensions, from DNA extracted from pure or mixed cultures or from stool specimens. Amplification of thevirFgene was also achieved from strains ofY. pseudotuberculosiscarrying the 70 kb plasmid but not with preparations from other relatedYersiniaspecies or from other members of the familyEnterobacteriaceae. The detection limit we established was 5–10 colony forming units per millilitre (cfu/ml) and 1·0 pg of DNA.

scholarly journals Detection of Salmonella Enteritidis in Equine Feces using the Polymerase Chain Reaction and Genus-Specific Oligonucleotide Primers

1995 ◽  
Vol 7 (2) ◽  
pp. 219-222 ◽  
Author(s):  
Noah D. Cohen ◽  
Deeann E. Wallis ◽  
Holly L. Neibergs ◽  
Billy M. Hargis
Keyword(s):  
Polymerase Chain Reaction ◽  
Salmonella Enteritidis ◽  
Pcr Detection ◽  
Chain Reaction ◽  
Specific Primers ◽  
Fecal Samples ◽  
Oligonucleotide Primers ◽  
Colony Forming Units ◽  
Polymerase Chain ◽  
Culture Negative

Salmonella was identified in feces from horses, using the polymerase chain reaction (PCR) and genus-specific oligonucleotide primers. Feces from healthy horses were determined to be culture negative and PCR negative for Salmonella. Fecal samples were inoculated with known numbers of colony-forming units (CFU) of S. enteritidis. The fecal samples were enriched overnight in tetrathionate broth, and then DNA was extracted and amplified by PCR using genus-specific primers. Sensitivity of the assay extended to 100 CFU Salmonella enteritidis/g feces; sensitivity of microbiologic culture with enrichment extended to 100 CFU Salmonella enteritidis/g feces. Feces that were not inoculated with S. enteritidis were negative by the PCR. Detection of salmonellae in feces was possible using the PCR within 24 hours from the time of submission of samples. Because samples were enriched, isolates were available for determining antibiograms and serologic grouping or typing.

Bio-inspired self-healing cementitious mortar using Bacillus subtilis immobilized on nano-/micro-additives

2018 ◽  
Vol 30 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Rao Arsalan Khushnood ◽  
Siraj ud din ◽  
Nafeesa Shaheen ◽  
Sajjad Ahmad ◽  
Filza Zarrar
Keyword(s):  
Compressive Strength ◽  
Bacillus Subtilis ◽  
Iron Oxide ◽  
Cement Mortar ◽  
Healing Process ◽  
Main Concern ◽  
Scanning Electron Micrographs ◽  
Self Healing ◽  
Micro Cracks ◽  
Cracked Specimens

Bio-inspired self-healing strategies are much innovative and potentially viable for the production of healable cement mortar matrix. The present research explores the feasibility of gram-positive “Bacillus subtilis” microorganisms in the effective healing of nano-/micro-scale-induced structural and non-structural cracks. The main concern related to the survival of such microorganisms in cementitious environment has been successfully addressed by devising proficient immobilization scheme coherently. The investigated immobilizing media includes iron oxide nano-sized particles, micro-sized limestone particles, and milli-sized siliceous sand. The effect of induced B. subtilis microorganisms immobilized on nano-micro-additives was analyzed by the quantification of average compressive resistance of specimens (ASTM C109) and healing evaluation. The healing process was mechanically gauged by compressive strength regain of pre-cracked specimens after the healing period of 28 days. The pre-cracking load was affixed at 80% of ultimate compressive stress “[Formula: see text]” while the age of pre-cracking was kept variable as 3, 7, 14, and 28 days to precisely correlate healing effectiveness as the function of cracking period. The healing mechanism was further explored by examining the healed micro-crack using field emission scanning electron micrographs, energy dispersive x-ray spectrographs, and thermogravimetry. The results revealed that B. subtilis microorganisms contribute extremely well in the improvement of compressive strength and efficient healing process of pre-cracked cement mortar formulations. The iron oxide nano-sized particles were found to be the most effective immobilizer for preserving B. subtilis microbes till the generation of cracks followed by siliceous sand and limestone particles. The micro-graphical and chemical investigations endorsed the mechanical measurements by evidencing calcite precipitation in the induced nano-/micro-cracks as a result of microbial activity.

Improvement of capture efficacy of immunomagnetic beads forCampylobacter jejuniusing reagents that alter its motility

2013 ◽  
Vol 59 (7) ◽  
pp. 511-514 ◽  
Author(s):  
Hongsheng Huang ◽  
Beverley Phipps-Todd
Keyword(s):  
Campylobacter Jejuni ◽  
Contact Time ◽  
Detection Limits ◽  
Immunological Reactivity ◽  
Immunomagnetic Beads ◽  
Chain Reaction ◽  
Slowing Down ◽  
Colony Forming Units ◽  
High Detection ◽  
Polymerase Chain

Previous studies using the immunomagnetic beads separation (IMS) technique have shown high detection limits of live campylobacters but low detection limits of formalin-killed campylobacters. The present study investigated if the addition of various concentrations of reagents that alter the motility of live Campylobacter jejuni could enhance the recovery of the organisms by IMS. The addition of 5% glycerol, 0.001% formalin, 10% polyethylene glycol, or 0.001% agarose in a buffer slowed down the movement of C. jejuni and increased the recovery of live C. jejuni, using beads coated with specific monoclonal antibodies (mAbs). The highest recovery yielded was 5.2- ± 3.3-fold with 5% glycerol at 105colony-forming units (CFU)·mL−1. The addition of 5% glycerol also improved isolation at lower concentrations of C. jejuni (102to 104CFU·mL−1) in buffer. The recovery by IMS of C. jejuni killed by 1% formalin was increased up to as high as 17-fold compared with the recovery of live organisms, as detected using a real-time polymerase chain reaction assay. The reagents investigated did not enhance the immunological reactivity of the mAbs to this organism. These results indicate that the addition of several reagents enhanced the capture of C. jejuni by IMS, which could be partially due to the slowing down of the movement or the altering of the motility of C. jejuni and to the increasing of the contact time between C. jejuni and immunomagnetic beads.

scholarly journals Molecular identification of Candida dubliniensis isolated from oral lesions of HIV-positive and HIV-negative patients in São Paulo, Brazil

2006 ◽  
Vol 48 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Jorge Kleber Chavasco ◽  
Claudete Rodrigues Paula ◽  
Mario Hiroyuki Hirata ◽  
Natanael Atilas Aleva ◽  
Carlos Eduardo de Melo ◽  
...  
Keyword(s):  
Classical Method ◽  
Culture Collection ◽  
Candida Dubliniensis ◽  
Hiv Positive ◽  
Oral Lesions ◽  
Chain Reaction ◽  
Biochemical Characteristics ◽  
Two Samples ◽  
Polymerase Chain ◽  
Hiv Negative

Candida dubliniensis is a new, recently described species of yeast. This emerging oral pathogen shares many phenotypic and biochemical characteristics with C. albicans, making it hard to differentiate between them, although they are genotypically distinct. In this study, PCR (Polymerase Chain Reaction) was used to investigate the presence of C. dubliniensis in samples in a culture collection, which had been isolated from HIV-positive and HIV-negative patients with oral erythematous candidiasis. From a total of 37 samples previously identified as C. albicans by the classical method, two samples of C. dubliniensis (5.4%) were found through the use of PCR. This study underscores the presence of C. dubliniensis, whose geographical and epidemiological distribution should be more fully investigated.

scholarly journals Fosfatasa Alcalina (ALP) y Runx2 en cultivos celulares de osteoblastos estimulados con campo eléctrico

Revista Med ◽  
2012 ◽  
Vol 20 (2) ◽  
pp. 14 ◽  
Author(s):  
Jorge Arturo Rey Cubillos ◽  
Leonardo Lareo ◽  
Sandra Gutiérrez ◽  
Marcela Godoy Corredor
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcription ◽  
Culture Collection ◽  
American Type Culture Collection ◽  
Chain Reaction ◽  
Qrt Pcr ◽  
Polymerase Chain

<p>El objeto de este estudio fue identificar el estímulo eléctrico que debe aplicarse en cultivos celulares de osteoblastos (Ob) para aumentar la expresión del gen de Fosfatasa Alcalina (ALP) y el factor de transcripción Runx2. Se cultivaron Ob de la American Type Culture Collection (ATCC) Ref. CRL 11372. Los cultivos se estimularon del día cinco, cuando las células presentaron confluencia, hasta el día ocho. El estímulo aplicado a cada grupo experimental fue de 100mV, 200mV, 300mV, 400mV y 500mV respectivamente, se cultivó un grupo control no estimulado con cada grupo experimental. El campo eléctrico se generó con corriente alterna (AC) y se aplicó mediante dos placas de aluminio ubicadas de forma lateral y paralela a los frascos de cultivo de 25cm2. Los niveles de expresión de mRNA se midieron con la técnica quantitative reverse transcription polymerase chain reaction (qRT–PCR). Con la aplicación de campo generado con AC aumentó la expresión del factor de transcripción RunX2 en proporción directa al aumento del voltaje aplicado. La expresión del gen de ALP fue inversamente proporcional a la aplicación del estímulo y se identificó una diferencia significativa entre la presencia y ausencia del estímulo, siendo mayor en ausencia del estímulo. El campo eléctrico generó una señal que puede aumentar o disminuir la expresión de los genes que median la formación de tejido óseo. En el caso de Runx2, favoreció la diferenciación de células mesenquimales a Ob con la consecuente actividad de remodelación y formación del tejido óseo.</p>

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