scholarly journals Microbiologically induced aesthetic and structural changes to dimension stone

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Christine C. Gaylarde ◽  
Jose Antonio Baptista-Neto
Keyword(s):  
Biofilm Formation ◽  
Acid Production ◽  
Structural Damage ◽  
Structural Changes ◽  
Higher Plants ◽  
Dimension Stone ◽  
Stone Cell ◽  
Natural Rock ◽  
And Control ◽  
Initial Biofilm

AbstractDimension stone is natural rock prepared for building use. It is rapidly colonised by microorganisms that cause discoloration (mainly cyanobacteria, algae and fungi) and structural damage. Microbial mobilisation of ions leads to new superficial or internal deposits, weakening the structure. Cyanobacteria and fungi may penetrate, filling pores or creating new spaces. Lichens, fungus/phototroph associations, colonise surfaces and damage stone through ingrowing rhizines and acid production. Initial degradation produces conditions suitable for germination of seeds of higher plants and further destruction. Emerging techniques to elucidate stone-cell interactions and control of initial biofilm formation that eventuates in stone disintegration are discussed.

Drought Induced Structural Changes in Developing Chloroplasts of Jalapeno Pepper (Capsicum annuum)

2001 ◽  
Vol 7 (S2) ◽  
pp. 66-67 ◽  
Author(s):  
Kristine Fambrough ◽  
Soumitra Ghoshroy
Keyword(s):  
Structural Changes ◽  
Higher Plants ◽  
Turgor Pressure ◽  
Prolamellar Body ◽  
Control Group ◽  
Time Intervals ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
And Control ◽  
Pepper Plants

Chloroplasts, present in leaves of higher plants have an extensive, folded network of photosynthetic membranes. These membranes have closely appressed (grana) and non-appressed (stroma) regions and they are responsible for the conversion of solar energy into biochemically useful forms. Light plays an important role for the development of mature chloroplasts from proplastids. However, when seeds germinate in the dark, the proplastids do not form mature chloroplasts and instead they form etioplasts. The etioplasts contain a compact, highly regular lattice of inner membranes called prolamellar body. Exposure of dark grown seedlings to light induces formation of fully mature chloroplasts from etioplasts. Plant growth and development is dependent on various environmental factors and drought has profound effect on plant metabolism. Leaves depend on adequate water for both turgor pressure and photosynthesis. Turgor pressure enables nutrients in the form of carbon and minerals to be transported from soil to leaves where they are needed for synthesis of organic compounds. in this study we evaluated the influence of drought on the ultrastructure of developing chloroplasts in pepper plants.Jalapeno pepper plants were grown from seeds in the dark and drought was induced to experimental group of plants after they developed the first pair of primary leaves. The dark grown control plants received water throughout the drought induction period. At the end of tenth day of drought, plants in both control and experimental groups were exposed to light for up to 48 hours and leaf samples from both groups were obtained at various time intervals after exposure to light. The samples were fixed, dehydrated and embedded for transmission electron microscopy. Ultrathin sections were made, observed under a Hitachi H7000 TEM and data were collected for ultrastructural study. The mature chloroplast and etioplast structures were compared between experimental and control group of plants.

scholarly journals Effects of Irregularities in the Microstructure of Surgical Instruments on Microbial Adherence and Challenges for Processing

2020 ◽  
Vol 41 (S1) ◽  
pp. s208-s208
Author(s):  
Sintia Evangelista ◽  
Adriana Oliveira
Keyword(s):  
Biofilm Formation ◽  
Structural Damage ◽  
Microbial Growth ◽  
Structural Changes ◽  
Surgical Instruments ◽  
Surgical Instrument ◽  
E Coli ◽  
Prolonged Contact ◽  
Additional Challenge ◽  
Microbial Adherence

Background: A surgical instrument can have areas that pose different challenges to cleaning, hindering the removal of dirt. This can directly impact the effectiveness of its processing while potentially promoting cross contamination. Moreover, structural changes (ie, cracks or fissures) on the instrument surface, although rarely addressed, can act as reservoirs for microorganisms, contributing to organic matter retention, microbial growth, and biofilm formation. Our aim was to determine the effect of irregularities in the microstructure of surgical instruments on microbial adherence. Methods: We analyzed 18 fragments of 3 distinct areas of new crile forceps: the ratchet, shank, and jaw. Of these fragments, 15 were artificially contaminated by immersion in tryptic soy broth containing 10 6 CFU/mL of Escherichia coli (ATCC 25922), for 4, 6, 8, and 12 hours of incubation at 37C with agitation at 100 rpm. The other 3 fragments were used as controls. All fragments were subjected to scanning electron microscopy to evaluate the adhesion of the microorganism. Results: An irregular surface was found in 3 of 6 shank fragments (50%) (Fig. 1) and in all the jaw and ratchet fragments, grooves, and cracks. Initially, there was less adherence of E. coli to the smooth shank surface after contamination, but the concentration of the microorganism increased progressively over time in relation to that in the jaw or ratchet at the same time, and a higher concentration occurred in the cracks and grooves. Conclusions: Structural damage was observed in all fragments, especially in the ratchet and jaw areas, favoring microbial accumulation. Microorganisms housed in the cracks and grooves were better protected from removal by scrubbing with a brush (being unlikely to reach them), making these areas a microbial reservoir and source of contamination. Prolonged contact of the instrument with the contaminating microorganism allowed for greater adherence, even on the smooth areas. The results support the relevance of the early onset of cleaning, considering that even microscopic changes on the surface of the instrument may represent an additional challenge to its effective processing.Funding: NoneDisclosures: None

Evaluation of single-electron movies of glutamine synthetase molecules

1983 ◽  
Vol 41 ◽  
pp. 280-281
Author(s):  
W. Kunath ◽  
E. Zeitler ◽  
M. Kessel
Keyword(s):  
Electron Microscope ◽  
Glutamine Synthetase ◽  
Electron Irradiation ◽  
Structural Damage ◽  
Structural Changes ◽  
Single Electron ◽  
Continuous Series ◽  
Digital Recording ◽  
Recording Device ◽  
Low Exposure

The features of digital recording of a continuous series (movie) of singleelectron TV frames are reported. The technique is used to investigate structural changes in negatively stained glutamine synthetase molecules (GS) during electron irradiation and, as an ultimate goal, to look for the molecules' “undamaged” structure, say, after a 1 e/Å2 dose.The TV frame of fig. la shows an image of 5 glutamine synthetase molecules exposed to 1/150 e/Å2. Every single electron is recorded as a unit signal in a 256 ×256 field. The extremely low exposure of a single TV frame as dictated by the single-electron recording device including the electron microscope requires accumulation of 150 TV frames into one frame (fig. lb) thus achieving a reasonable compromise between the conflicting aspects of exposure time per frame of 3 sec. vs. object drift of less than 1 Å, and exposure per frame of 1 e/Å2 vs. rate of structural damage.

Food Security Doctrine – What Has Changed in 2020

2020 ◽  
pp. 7-10
Author(s):  
T.M. Yarkova ◽  
Keyword(s):  
Food Security ◽  
Public Administration ◽  
Russian Federation ◽  
Structural Changes ◽  
Food Policy ◽  
Assessment System ◽  
Security Assessment ◽  
Social Bias ◽  
The Russian Federation ◽  
And Control

This article presents an analysis of the changes that have occurred in one of the most important state documents - the Food Security Doctrine of the Russian Federation. Criticism of this document can be traced in many scientific works: some experts attribute the Doctrine only to a program document, while others expect it to be implement and control, i.e. much more in practice. An assessment of the significance and essence of such a document as the doctrine as a whole made it possible to determine its place both in the system of public administration and the degree of its significance in the regulatory field. Based on the findings, an attempt was made to analyze changes in the new Doctrine of Food Security of the Russian Federation, approved by Decree of the President of Russia No. 20 of 01.21.2020. Structural changes in the new Doctrine are highlighted, as well as a critical assessment of the features of all its main sections. The greatest changes were revealed in the state food security assessment system, and it was also determined that the new version of the Doctrine has a greater social bias. If there are positive changes, some omissions of the most important areas of agri-food policy have been identified, which, despite their absence or insufficient reflection in the Doctrine, can be presented and decided at the level of subsequent documents, but only if the Doctrine in practice will be a fundamental document of public administration and regulatory framework.

scholarly journals Imaging of Joint and Soft Tissue Involvement in Systemic Lupus Erythematosus

2021 ◽  
Vol 23 (9) ◽  
Author(s):  
Andrea Di Matteo ◽  
Gianluca Smerilli ◽  
Edoardo Cipolletta ◽  
Fausto Salaffi ◽  
Rossella De Angelis ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Soft Tissue ◽  
Lupus Erythematosus ◽  
Structural Damage ◽  
Structural Changes ◽  
Soft Tissues ◽  
Imaging Techniques ◽  
Joint Involvement ◽  
Systemic Lupus ◽  
Muscle Involvement

Abstract Purpose of Review To highlight the potential uses and applications of imaging in the assessment of the most common and relevant musculoskeletal (MSK) manifestations in systemic lupus erythematosus (SLE). Recent Findings Ultrasound (US) and magnetic resonance imaging (MRI) are accurate and sensitive in the assessment of inflammation and structural damage at the joint and soft tissue structures in patients with SLE. The US is particularly helpful for the detection of joint and/or tendon inflammation in patients with arthralgia but without clinical synovitis, and for the early identification of bone erosions. MRI plays a key role in the early diagnosis of osteonecrosis and in the assessment of muscle involvement (i.e., myositis and myopathy). Conventional radiography (CR) remains the traditional gold standard for the evaluation of structural damage in patients with joint involvement, and for the study of bone pathology. The diagnostic value of CR is affected by the poor sensitivity in demonstrating early structural changes at joint and soft tissue level. Computed tomography allows a detailed evaluation of bone damage. However, the inability to distinguish different soft tissues and the need for ionizing radiation limit its use to selected clinical circumstances. Nuclear imaging techniques are valuable resources in patients with suspected bone infection (i.e., osteomyelitis), especially when MRI is contraindicated. Finally, dual energy X-ray absorptiometry represents the imaging mainstay for the assessment and monitoring of bone status in patients with or at-risk of osteoporosis. Summary Imaging provides relevant and valuable information in the assessment of MSK involvement in SLE.

scholarly journals Motility activity, slime production, biofilm formation and genetic typing by ERIC-PCR for Pseudomonas aeruginosa strains isolated from bovine and other sources (human and environment)

2014 ◽  
Vol 17 (2) ◽  
pp. 321-329 ◽  
Author(s):  
K. Wolska ◽  
P. Szweda ◽  
K. Lada ◽  
E. Rytel ◽  
K. Gucwa ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bovine Mastitis ◽  
Twitching Motility ◽  
Phenotypic Properties ◽  
Biofilm Production ◽  
Abiotic Surfaces ◽  
Hospital Patients ◽  
Relationship Of ◽  
Initial Biofilm ◽  
Different Sources

AbstractThe molecular-typing strategy, ERIC-PCR was used in an attempt to determine the genomic relationship of 28 P. aeruginosa strains isolated from faeces of healthy bovine, bovine mastitis and from faeces of hospital patients as well as from environment. ERIC-PCR fingerprinting revealed large molecular differentiation within this group of isolates. Twenty two out of 28 strains tested generated unique patterns of DNA bands and only three genotypes consisted of two isolates each were identified. We also tested the P. aeruginosa isolates for their ability to form a biofilm on abiotic surfaces including polyvinylchloride and polystyrene. Different biofilm-forming abilities were demonstrated among strains; however, most of them (64.3%) showed moderate-biofilm forming ability. The strains with increased swimming and twitching motility displayed elevated biofilm formation. However, a negative correlation was found between slime and initial biofilm production. On the basis of the results obtained, we suggest that there are no major differences in phenotypic properties between P. aeruginosa strains isolated from different sources

scholarly journals Risk factors and biofilm formation analyses of hospital-acquired infection of Candida pelliculosa in a neonatal intensive care unit

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Zhijie Zhang ◽  
Yu Cao ◽  
Yanjian Li ◽  
Xufang Chen ◽  
Chen Ding ◽  
...  
Keyword(s):  
Risk Factors ◽  
Intensive Care Unit ◽  
Biofilm Formation ◽  
Prevention And Control ◽  
Neonatal Intensive Care ◽  
Infection Prevention ◽  
Infection Prevention And Control ◽  
Anti Fungal ◽  
Hospital Acquired ◽  
And Control

Abstract Background Candida pelliculosa is an ecological fungal species that can cause infections in immunocompromised individuals. Numerous studies globally have shown that C. pelliculosa infects neonates. An outbreak recently occurred in our neonatal intensive care unit; therefore, we aimed to evaluate the risk factors in this hospital-acquired fungal infection. Methods We performed a case-control study, analysing the potential risk factors for neonatal infections of C. pelliculosa so that infection prevention and control could be implemented in our units. Isolated strains were tested for drug resistance and biofilm formation, important factors for fungal transmission that give rise to hospital-acquired infections. Results The use of three or more broad-spectrum antimicrobials or long hospital stays were associated with higher likelihoods of infection with C. pelliculosa. The fungus was not identified on the hands of healthcare workers or in the environment. All fungal isolates were susceptible to anti-fungal medications, and after anti-fungal treatment, all infected patients recovered. Strict infection prevention and control procedures efficiently suppressed infection transmission. Intact adhesin-encoding genes, shown by genome analysis, indicated possible routes for fungal transmission. Conclusions The use of three or more broad-spectrum antimicrobials or a lengthy hospital stay is theoretically associated with the risk of infection with C. pelliculosa. Strains that we isolated are susceptible to anti-fungal medications, and these were eliminated by treating all patients with an antifungal. Transmission is likely via adhesion to the cell surface and biofilm formation.

scholarly journals Technological and Functional Assessment of Riboflavin Enriched Probiotic SoyCurd

Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 47
Author(s):  
Kapil Singh Narayan ◽  
Sakshi Gaurkhede ◽  
Virat Sharma ◽  
Ankur Kumar ◽  
Bharat Bhushan ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Functional Assessment ◽  
Functional Food ◽  
Acid Production ◽  
Functional Foods ◽  
Lactic Acid Production ◽  
Novel Approach ◽  
Probiotic Strains ◽  
And Control ◽  
Test Cultures

Preparation of soymilk-based product with probiotics is reasonably a novel approach in the field of fermented functional foods. The aim of this study was to develop riboflavin enriched fermented soy curds with either or combination of the two riboflavin producing probiotic strains of Lactobacillus plantarum i.e., MTCC 25432 (BBC32B) and MTCC 25433 (BBC33), and to compare the technological and functional properties of its developed products. Acidification rate and lactic acid production were enhanced with L. plantarum and its combination in a shorter time to reach pH 4.7. Hardness and cohesiveness were significantly (p < 0.05) higher for fermented soymilk by co-culture of L. plantarum followed by individual strains. Similarly, higher G′ (6.25 × 102 Pa), G” (2.30 × 103 Pa) and G* (8.00 × 102 Pa) values observed for the combination of both L. plantarum strains showed that the gel formed was firmer and had solid character. The riboflavin content of product developed with a combination of test cultures was significantly higher (342.11 µg/L) than individual cultures and control. The final product had a higher probiotic count (more than 9 log cfu/mL), which is also required for functional food containing probiotics.

Influence of Glucose Concentrations on Biofilm Formation, Motility, Exoprotease Production, and Quorum Sensing in Aeromonas hydrophila

2013 ◽  
Vol 76 (2) ◽  
pp. 239-247 ◽  
Author(s):  
IQBAL KABIR JAHID ◽  
NA-YOUNG LEE ◽  
ANNA KIM ◽  
SANG-DO HA
Keyword(s):  
Quorum Sensing ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Homoserine Lactone ◽  
Protease Production ◽  
Acyl Homoserine Lactone ◽  
Human Pathogen ◽  
Initial Biofilm ◽  
Motility Inhibition

Aeromonas hydrophila recently has received increased attention because it is opportunistic and a primary human pathogen. A. hydrophila biofilm formation and its control are a major concern for food safety because biofilms are related to virulence. Therefore, we investigated biofilm formation, motility inhibition, quorum sensing, and exoprotease production of this opportunistic pathogen in response to various glucose concentrations from 0.05 to 2.5% (wt/vol). More than 0.05% glucose significantly impaired (P &lt; 0.05) quorum sensing, biofilm formation, protease production, and swarming and swimming motility, whereas bacteria treated with 0.05% glucose had activity similar to that of the control (0% glucose). A stage shift biofilm assay revealed that the addition of glucose (2.5%) inhibited initial biofilm formation but not later stages. However, addition of quorum sensing molecules N-3-butanoyl-DL-homoserine lactone and N-3-hexanoyl homoserine lactone partially restored protease production, indicating that quorum sensing is controlled by glucose concentrations. Thus, glucose present in food or added as a preservative could regulate acyl-homoserine lactone quorum sensing molecules, which mediate biofilm formation and virulence in A. hydrophila.

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