scholarly journals Study of Surface Structure Changes for Selected Ceramics Used in the CAD/CAM System on the Degree of Microbial Colonization, In Vitro Tests

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Maciej Dobrzynski ◽  
Magdalena Pajaczkowska ◽  
Joanna Nowicka ◽  
Aleksander Jaworski ◽  
Piotr Kosior ◽  
...  
Keyword(s):  
Dental Materials ◽  
Lactobacillus Rhamnosus ◽  
Microbial Colonization ◽  
In Vitro Tests ◽  
Adhesive Properties ◽  
Structure Changes ◽  
Cad Cam ◽  
Biofilm Development ◽  
Made In

In the article has been presented an analysis of susceptibility of selected dental materials, made in the CAD/CAM technology. The morphology and structural properties of selected dental materials and their composites were determined by using XRPD (X-ray powder diffraction) techniques, as well as the IR (infrared) spectroscopy. Moreover, an adhesion as well as development of biofilm by oral microorganisms has been studied. It has been shown that a degree of the biofilm development on the tested dental materials depended on microorganism genus and species. Streptococcus mutans has demonstrated the best adhesion to the tested materials in comparison with Candida albicans and Lactobacillus rhamnosus. However, the sintered materials such as IPS e.max® and the polished IPS e.max® have showed the best “anti-adhesive properties” in relation to S. mutans and L. rhamnosus that have not formed the biofilm on the polished IPS e.max® sample. Furthermore, S. mutans have not formed the biofilm on both surfaces. On the contrary to S. mutans and L. rhamnosus, C. albicans has demonstrated the adhesive properties in relation to the above-mentioned surfaces. Moreover, in contrast to S. mutans and C. albicans, L. rhamnosus has not formed the biofilm on the polished IPS Empress material.

scholarly journals Fungal Colonization and Biodeterioration of Plasticized Polyvinyl Chloride

2000 ◽  
Vol 66 (8) ◽  
pp. 3194-3200 ◽  
Author(s):  
Jeremy S. Webb ◽  
Marianne Nixon ◽  
Ian M. Eastwood ◽  
Malcolm Greenhalgh ◽  
Geoffrey D. Robson ◽  
...  
Keyword(s):  
Bacterial Colonization ◽  
Morphological Characteristics ◽  
Sole Source ◽  
Dioctyl Phthalate ◽  
Microbial Colonization ◽  
Fungal Colonization ◽  
In Vitro Tests ◽  
Rrna Gene ◽  
Microbial Succession

ABSTRACT Significant substratum damage can occur when plasticized PVC (pPVC) is colonized by microorganisms. We investigated microbial colonization of pPVC in an in situ, longitudinal study. Pieces of pPVC containing the plasticizers dioctyl phthalate and dioctyl adipate (DOA) were exposed to the atmosphere for up to 2 years. Fungal and bacterial populations were quantified, and colonizing fungi were identified by rRNA gene sequencing and morphological characteristics.Aureobasidium pullulans was the principal colonizing fungus, establishing itself on the pPVC between 25 and 40 weeks of exposure. A group of yeasts and yeast-like fungi, includingRhodotorula aurantiaca and Kluyveromyces spp., established themselves on the pPVC much later (after 80 weeks of exposure). Numerically, these organisms dominated A. pullulans after 95 weeks, with a mean viable count ± standard error of 1,000 ± 200 yeast CFU cm−2, compared to 390 ± 50 A. pullulans CFU cm−2. No bacterial colonization was observed. We also used in vitro tests to characterize the deteriogenic properties of fungi isolated from the pPVC. All strains of A. pullulans tested could grow with the intact pPVC formulation as the sole source of carbon, degrade the plasticizer DOA, produce extracellular esterase, and cause weight loss of the substratum during growth in vitro. In contrast, several yeast isolates could not grow on pPVC or degrade DOA. These results suggest that microbial succession may occur during the colonization of pPVC and that A. pullulans is critical to the establishment of a microbial community on pPVC.

scholarly journals First Report of Leaf Blight Caused by Alternaria longipes on Carrots in Israel

Plant Disease ◽  
2002 ◽  
Vol 86 (2) ◽  
pp. 186-186
Author(s):  
H. Vintal ◽  
D. Shtienberg ◽  
E. Shlevin ◽  
E. Ben-Noon
Keyword(s):  
Leaf Blight ◽  
In Vitro Tests ◽  
Northwestern Part ◽  
Potato Dextrose Agar Medium ◽  
Daucus Carota L ◽  
Mycelia Growth ◽  
Alternaria Dauci ◽  
Foliar Pathogens ◽  
Made In

Alternaria leaf blight, caused by Alternaria dauci (Köhn) Groves & Skolko, is one of the most devastating foliar pathogens of carrots (Daucus carota L.). Lesions appear as minute, necrotic, dark brown spots often initiated on the edge of the leaflet blade. They later enlarge in size and may merge into a large necrotic area, causing shriveling of the entire leaflet (1). In summer 2000, observations made in several carrot fields in the northwestern part of the Negev Region in Israel revealed infections that were atypical for A. dauci because they were initiated primarily in the middle section of the leaflet blade and were surrounded by a large yellowish area. A. longipes (Ellis & Everh.) E. Mason was consistently isolated from the lesions. Occasionally both A. longipes and A. dauci developed on the same leaves. The two pathogens differed in conidial morphology (size and shape of spore and beak) when cultured on potato dextrose agar medium. One hundred conidia of each species were measured. A. dauci conidia were 100 to 450 μm long and 6 to 15 μm wide, with a beak of up to 3 times the length of the conidium; A. longipes conidia were 35 to 110 μm long and 11 to 21 μm wide, and the beak measured one-third to one-half the length of the conidium. These measurements corresponded to the sizes listed previously (2). Inoculation of greenhouse-grown plants and completion of Koch's postulates confirmed that A. longipes is pathogenic to carrots. Conidia of both species germinated at temperatures from 5 to 36°C. In vitro tests revealed that A. longipes was less sensitive than A. dauci to fungicides commonly used in Israel in carrot fields. A fifty percent effective dose of chlorothalonil and difenoconazole was 3.0 and 0.2 μg a.i./ml, respectively, for mycelia growth of A. dauci, whereas the corresponding values for A. longipes were 10.5 and 3.0 μg a.i./ml, respectively. The prevalence of A. longipes in carrot fields and the influence of this pathogen on yields are currently not known. References: (1) I. Barash et al. Physiol. Plant Pathol. 19:7, 1981. (2) M. B. Ellis. Dematiaceous Hyphomycetes. CMI. Kew, Surrey, England, 1971.

An Automatic Suturing Machine for Intestinal Anastomosis: Advantages Compared With Hand-Suturing Technique

2018 ◽  
Vol 26 (2) ◽  
pp. 209-218 ◽  
Author(s):  
Sanaz Mosafer Khoorjestan ◽  
Gholamreza Rouhi
Keyword(s):  
Mechanical Strength ◽  
Intestinal Anastomosis ◽  
Tensile Tests ◽  
Point Of View ◽  
In Vitro Tests ◽  
System A ◽  
Expert Surgeon ◽  
Suturing Methods ◽  
Made In

One of the main procedures in intestinal surgery is anastomosis, which is mostly performed by stapling or hand suturing. Due to limitations of these methods, a novel automatic suturing machine was designed and fabricated in this study, equipped with a needle-driving system; a thread control mechanism, and a linear mechanism, which is applicable in intestinal anastomosis by making continuous sutures. The main advantages of the fabricated machine are employing biocompatible suture, from the tissue’s adaptation point of view, and making a uniform suturing pattern, independent of surgeon’s skill, and thus offering a greater strength than the hand-sutured specimen. In order to evaluate the capability of the fabricated machine and investigate the validity of the hypothesis made in this study, that is, a more uniform suture will result in a greater mechanical strength of the sutured tissue, in vitro tests were performed on human intestine specimens, which were manually sutured by an expert surgeon and by the automatic suturing machine. The tensile tests with an elongation rate of 5 mm/min were done for 90 specimens, in 9 groups with various suturing configurations. The optimum pattern, from the mechanical strength point of view, was found to be the same in both manual and automatic suturing methods, that is, h7 d6 ( h = distance of suture from the edge of the tissue = 7 mm, and d = distance between stitches = 6 mm). It was also shown that the maximum breaking strength, for the best suturing pattern, h7 d6, is significantly greater when the automatic suturing machine was employed, compared with the hand-sutured tissue ( P < .001).

scholarly journals Bisphenol A Analogues: A Brief Review of their Occurrence in Food, Biological Samples and Endocrine Effects

2020 ◽  
Vol 2 (4) ◽  
pp. 89-94
Author(s):  
Nikola Knizatova ◽  
Katarína Tokárová ◽  
Hana Greifová ◽  
Tomáš Jambor ◽  
Peter Massányi ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Human Health ◽  
Human Exposure ◽  
Food Packaging ◽  
In Vitro Tests ◽  
Endocrine Disrupting Chemical ◽  
Endocrine Disrupting ◽  
Made In

Bisphenol A (BPA) is the most well-known compound from the bisphenol family. There is increasing evidence that bisphenol BPA used in plastics, receipts, food packaging, and other products might be harmful to human health due to its actions as an endocrine-disrupting chemical, therefore BPA is being replaced by compounds very similar in structure, but data on the occurrence and effects of these BPA analogs are limited. Therefore, there is increasing concern regarding human exposure to bisphenol analogs (BPs) due to their widespread use and potential adverse effects. The main objective of this work was to investigate human exposure to BPs and the associated endocrine activities. We performed a literature review of the available research made in humans, in in vivo and in vitro tests. The findings support the idea that exposure to BPs may have an impact on human health, especially in terms of endocrine disruption.

Evaluation of the Adhesion of a Novel Design of Veneers to Dental Materials

2017 ◽  
Vol 68 (9) ◽  
pp. 2125-2128
Author(s):  
Alexandra Cristina Maroiu ◽  
Cosmin Sinescu ◽  
Radu Negru ◽  
Liviu Marsavina ◽  
Ioana Delia Bretean ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
High Performance ◽  
Dental Materials ◽  
In Vitro Study ◽  
The Novel ◽  
Adhesive Properties ◽  
Computer Aided ◽  
Aided Design ◽  
Novel Design

The aim of this in vitro study was to assess a new design that, to our knowledge, we have introduced (patent pending) for indirect dental veneers. Their effect on the retention and adhesive properties at their interfaces have been studied. Fourteen high performance polymeric (PEEK) dental veneers have been elaborated using a computer-aided-design (CAD) software and then milled using a computer-aided-machine (CAM). They were divided in two experimental groups: seven classical veneers with a liniar marginal contour and seven dental veneers with the novel proposed sinusoidal marginal design. All the samples have been bonded to polymeric blocks that had the vestibular face prepared in a specific way for each group. The values of the retention and adhesive forces were tested in vitro by applying bending forces on the incisal edge of the veneers, from the oral to the vestibular direction. A 50% increase of the values of these forces for the novel design with regard to the classical one has been demonstrated through the study.

scholarly journals Bisphenol A Analogues in Food and Their Hormonal and Obesogenic Effects: A Review

Nutrients ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 2136 ◽  
Author(s):  
Andújar ◽  
Gálvez-Ontiveros ◽  
Zafra-Gómez ◽  
Rodrigo ◽  
Álvarez-Cubero ◽  
...  
Keyword(s):  
Literature Review ◽  
Bisphenol A ◽  
Human Health ◽  
Health Effects ◽  
Human Exposure ◽  
In Vitro Tests ◽  
Adverse Health Effects ◽  
Made In

Bisphenol A (BPA) is the most well-known compound from the bisphenol family. As BPA has recently come under pressure, it is being replaced by compounds very similar in structure, but data on the occurrence of these BPA analogues in food and human matrices are limited. The main objective of this work was to investigate human exposure to BPA and analogues and the associated health effects. We performed a literature review of the available research made in humans, in in vivo and in vitro tests. The findings support the idea that exposure to BPA analogues may have an impact on human health, especially in terms of obesity and other adverse health effects in children.

Effect of prostacyclin on pulmonary vascular response to thrombin in awake sheep

1986 ◽  
Vol 60 (2) ◽  
pp. 546-553 ◽  
Author(s):  
M. B. Perlman ◽  
S. K. Lo ◽  
A. B. Malik
Keyword(s):  
Platelet Aggregation ◽  
Control Group ◽  
In Vitro Tests ◽  
Neutrophil Chemotaxis ◽  
Plasma Protein Concentration ◽  
Platelet Counts ◽  
Protein Clearance ◽  
Pulmonary Arterial ◽  
Made In

We determined the effects of infusion of prostacyclin (PGI2) and 6-alpha-carba-PGI2 (6-cPGI2), a stable PGI2 analogue, on pulmonary transvascular fluid and protein fluxes after intravascular coagulation induced by thrombin. Studies were made in control awake sheep prepared with lung lymph fistulas (n = 6) and in similarly prepared awake sheep pretreated with either 6-cPGI2 (n = 5) or PGI2 (n = 5). Both prostacyclin compounds (500 ng X kg-1 X min-1) were infused intravenously. All groups were challenged with 80 U/kg thrombin. Pulmonary arterial pressure (Ppa), pulmonary vascular resistance (PVR), pulmonary lymph flow (Qlym), lymph protein clearance (Qlym X lymph/plasma protein concentration ratio), and neutrophil and platelet counts were determined. In vitro tests assessed sheep neutrophil chemotaxis and chemiluminescence and platelet aggregation. In both 6-cPGI2 and PGI2 groups, the increases in Qlym after thrombin were less than those in the control group. The increase in lymph protein clearance in the 6-cPGI2 group was the same as that in control, whereas the increase in clearance in the PGI2 group was reduced. PVR and Ppa increased to a greater extent in the 6-cPGI2 group than in the control group, whereas the increases in PVR and Ppa were inhibited in the PGI2 group. Neutrophil and platelet counts decreased after thrombin in PGI2 and 6-cPGI2 groups, as they did in the control group. Neither 6-cPGI2 altered neutrophil chemotaxis induced by thrombin and chemiluminescence induced by opsonized zymosan. Both prostacyclin compounds inhibited platelet aggregation induced by ADP or thrombin.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Methyl Potassium Siliconate and Siloxane Inhibit the Formation of Multispecies Biofilms on Ceramic Roof Tiles: Efficiency and Comparison of Two Common Water Repellents

2021 ◽  
Vol 9 (2) ◽  
pp. 394
Author(s):  
Mattea Romani ◽  
Claire Carrion ◽  
Frédéric Fernandez ◽  
Philippe Lebaron ◽  
Raphaël Lami
Keyword(s):  
Building Materials ◽  
Microbial Colonization ◽  
Water Repellent ◽  
Colonization Patterns ◽  
Biofilm Development ◽  
Multispecies Biofilms ◽  
Water Repellents

Ceramic roof tiles are widespread marketed building materials, rapidly colonized by microorganisms that form multispecies biofilms on their surface and play crucial roles in biodeterioration processes. Coating tiles with water repellents is a pervasive industrial strategy employed to prevent liquid water penetration and slow biodeterioration. Very few studies have examined the links between the characteristics of water-repellent coatings and biofilm colonization patterns. Our work aims to compare the effects of coating tiles with two common water repellents (siliconate and siloxane) on the growth of colonizing microbes. We combined in situ exposure of tiles for over six years and macroscopic and microscopic observations with in vitro biotests, relying on the use of algal and fungal models. Our data showed that (1) tiles coated with water repellents were macroscopically less colonized by lichens (2) a significant fungal biofilm development at the microscopic scale (3) water repellents had very contrasting effects on our model strains. These data reinforce the great interest for industry to conduct more studies linking the nature of the water repellents with the composition of colonizing multispecies biofilms. The long-term objective is to improve the available water repellents and better adapt their selection to the nature of microbial colonization.

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