Evaluation of polymerization shrinkage of resin cements through in vitro and in situ experiments

2014 ◽  
Author(s):  
A. P. G. O. Franco ◽  
L. Z. Karam ◽  
C. A. Pulido ◽  
O. M. M. Gomes ◽  
H. J. Kalinowski
Keyword(s):  
Resin Cements ◽  
Polymerization Shrinkage ◽  
In Situ Experiments

ANG II modifies cardiomyocyte function via extracardiac and intracardiac neurons: in situ and in vitro studies

1997 ◽  
Vol 272 (3) ◽  
pp. R766-R775 ◽  
Author(s):  
M. Horackova ◽  
J. A. Armour
Keyword(s):  
Guinea Pig ◽  
Receptor Antagonist ◽  
Neuronal Activity ◽  
Ang Ii ◽  
Arterial Blood ◽  
Cardiac Ganglia ◽  
In Situ Experiments ◽  
Anesthetized Dogs

To determine whether angiotensin II (ANG II) affects cardiac performance via neurons in intrathoracic cardiac ganglia, studies were performed on anesthetized dogs. To exclude possible vascular regulatory effects of ANG II, experiments were also performed using long-term cultures of adult guinea pig ventricular cardiomyocytes with or without intrathoracic neurons. 1) In in situ experiments in 10 anesthetized dogs, cardiac augmentation occurred when ANG II (10 microl or 0.1 ml; 10-100 microM) was administered into limited loci within acutely decentralized stellate or middle cervical ganglia that were neurally connected to, but not those disconnected from, the heart. In another 18 dogs, ANG II increased intrinsic cardiac neuronal activity when administered adjacent to such neurons or into their local arterial blood supply. Ventricular ionotropic effects elicited by ANG II were eliminated by timolol, whereas increases in intrinsic cardiac neuronal activity were not affected. Effects elicited by ANG II were eliminated by administration of a selective AT1 receptor antagonist (losartan) but not by a selective AT2 receptor antagonist (PD-123319). 2) In in vitro experiments, ANG II (100 nM) induced positive chronotropic effects on cultured adult guinea pig cardiomyocytes innervated with adult extrinsic or intrinsic cardiac neurons, but not those cultured without neurons. The frequency of calcium inward current (Ca(i)) transients (recorded by fura 2 fluorescence) increased in innervated cocultures but not in the noninnervated cardiomyocyte cultures; however, the amplitude of Ca(i) transients was not affected by ANG II in cultures or in freshly isolated adult guinea pig cardiomyocytes. ANG II-induced effects in cocultures were blocked by losartan but not PD-123319 or timolol. Thus 1) ANG II-sensitive neurons exist in intrathoracic extracardiac and intrinsic cardiac ganglia; 2) these neurons possess AT1 receptors; and 3) these neurons appear to act directly and indirectly via adrenergic neurons to enhance cardiomyocyte function.

scholarly journals Electrical impedance measurement system to assess in-situ experiments on epithelia under ELF magnetic fields exposure

2021 ◽  
Vol 19 (3) ◽  
pp. 217-226
Author(s):  
G. Domínguez ◽  
E. Cardiel ◽  
J.L Reyes ◽  
E. Sánchez ◽  
P.R. Hernández
Keyword(s):  
Impedance Spectroscopy ◽  
Magnetic Fields ◽  
Cell Cultures ◽  
Electrical Impedance ◽  
Controlled Environment ◽  
Spectroscopy Technique ◽  
In Situ Experiments ◽  
Impedance Spectroscopy Technique

Purpose: The development of an electric impedance meter based on the impedance spectroscopy technique, for in vitro and in situ experimentation, with cellular epithelia submitted to extremely low frequency magnetic fields in a controlled environment. Unlike other reported systems, a strength of the one presented here is that it avoids the influence of external factors on the experiment. Materials and methods: The designed system employs the electrical impedance values obtained by the impedance spectroscopy technique to determine the parameters of the simple equivalent electrical model of a cellular monolayer. The Madin-Darby Canine Kidney (MDCK) cell cultures were used as subjects of study in the experimental protocol. Results: The validation was carried out by comparing the transepithelial electrical impedance data of the cell cultures obtained with the developed system and those of the Cellzscope® commercial system used as the standard. Non-significant differences were obtained. Conclusion: It was confirmed that the developed system provides reliable values of transepithelial electrical impedance to experiment with cell cultures and take advantage of the controlled environment to reduce the effects of experimental management.

scholarly journals Agrobiological Interactions of Essential Oils of Two Menthol Mints: Mentha piperita and Mentha arvensis

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 59 ◽  
Author(s):  
Danuta Kalemba ◽  
Agnieszka Synowiec
Keyword(s):  
Biological Activities ◽  
Review Article ◽  
Mentha Piperita ◽  
Agricultural Pest ◽  
Mentha Arvensis ◽  
Botanical Pesticides ◽  
New Methods ◽  
In Situ Experiments

This review article discusses the active constituents and potential of two menthol mint oils, Mentha piperita (MPEO) and Mentha arvensis (MAEO), as natural sources for botanical pesticides. The biological activities of these menthol mint oils, which can be useful in agriculture, have been broadly researched, especially toward phytotoxic microorganisms. To a lesser extent, the insecticidal and herbicidal activities of mint EOs have also been studied. It is apparent that the prospect of using menthol mint oils in agriculture is increasing in popularity. A number of investigations showed that the in vitro efficacy of MPEO and MAEO, as well as that of their main constituent, menthol, is pronounced. The results of in vitro research are useful for choosing EOs for further investigations. However, it is clear that in situ experiments are crucial and should be more extensively developed. At the same time, known techniques are to be applied to this area and new methods should be worked out, aiming at the improvement of EOs’ pesticidal efficacy and cost-effectiveness, for future implementation in agricultural pest control.

scholarly journals Use of in-vitro experimental results to model in-situ experiments: bio-denitrification under geological disposal conditions

SpringerPlus ◽  
2013 ◽  
Vol 2 (1) ◽  
Author(s):  
Kaoru Masuda ◽  
Hiroshi Murakami ◽  
Yoshitaka Kurimoto ◽  
Osamu Kato ◽  
Ko Kato ◽  
...  
Keyword(s):  
Experimental Results ◽  
Geological Disposal ◽  
In Situ Experiments

scholarly journals In vitro and in situ study on characterizationand mechanismofthe intestinal absorptionof 2,3,5,4'-tetrahydroxy-stilbene-2-O-β-D-glucoside

2020 ◽  
Author(s):  
Cheng Wang ◽  
Yimeng Zhou ◽  
Xiaohong Gong ◽  
Li Zheng ◽  
Yunxia Li
Keyword(s):  
Intestinal Absorption ◽  
High Performance ◽  
Cell Monolayer ◽  
Absorption Mechanism ◽  
Pharmacological Activities ◽  
Concentration Time ◽  
In Situ Experiments ◽  
Basic Parameters

Abstract Background: 2,3,5,4'-tetrahydroxystilbence-2-O-β-D-glucoside(TSG) is a polyhydroxyphenolic compound, which exhibited a broad spectrum of pharmacological activities, such asanti-inflammatory, anti-depression, anti-oxidation and anti-atherosclerosis.However, the compound had poor bioavailability and the underlying absorption mechanisms had not been studied. Therefore, the purpose of this study was to investigate the intestinal absorption mechanism of TSG. Methods: This study used Caco-2 cell monolayer model and single-passintestinal perfusion modelto explore the gastrointestinal absorption mechanisms of TSG. The effects of basic parameters such as drug concentration, time and pH on the intestinal absorption of TSG were analyzed by high performance liquid chromatography.The absorption susceptibility of TSG to three inhibitors, P-gp inhibitors verapamil hydrochloride and quinidine, and MRP2 inhibitor probenecid were also assessed. Results: TSG was poorly absorbed in the intestines and the absorption of TSG in stomach is much higher than that in intestine. Both in vitro and in situ experiments showed that the absorption of TSG was saturated with increasing concentration and it was better absorbed in a weakly acidic environment pH 6.4. Moreover, TSG interacts with P-gp and MRP2, and TSG was not only the substrate of the P-gp and MRP2, but also affected the expression of P-gp and MRP2. Conclusions: It wasconcluded that the gastrointestinalabsorption mechanisms ofTSG involved processes passive transport and the participation ofefflux transporters.

In Vitro and In Situ Fiber Bragg Grating Sensor Analysis of Two Dental Resin Cements

2015 ◽  
Vol 33 (12) ◽  
pp. 2543-2548 ◽  
Author(s):  
Leandro Zen Karam ◽  
Ana Paula G. de O. Franco ◽  
Camilo A. Pulido ◽  
Osnara Maria Mongruel Gomes ◽  
Hypolito J. Kalinowski
Keyword(s):  
Fiber Bragg Grating ◽  
Fiber Bragg Grating Sensor ◽  
Bragg Grating ◽  
Dental Resin ◽  
Resin Cements ◽  
Sensor Analysis ◽  
Bragg Grating Sensor

Comparison of the Efficacy of a Hydrogen Peroxide Dry-Mist Disinfection System and Sodium Hypochlorite Solution for Eradication of Clostridium difficile Spores

2009 ◽  
Vol 30 (6) ◽  
pp. 507-514 ◽  
Author(s):  
F. Barbut ◽  
D. Menuet ◽  
M. Verachten ◽  
E. Girou
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hypochlorite ◽  
Environmental Contamination ◽  
Bacterial Count ◽  
Sodium Hypochlorite Solution ◽  
Hypochlorite Solution ◽  
Colony Forming Units ◽  
In Situ Experiments

Objective.To compare a hydrogen peroxide dry-mist system and a 0.5% hypochlorite solution with respect to their ability to disinfect Clostridium difficile-contaminated surfaces in vitro and in situ.Design.Prospective, randomized, before-after trial.Setting.Two French hospitals affected by C. difficile.Intervention.In situ efficacy of disinfectants was assessed in rooms that had housed patients with C. difficile infection. A prospective study was performed at 2 hospitals that involved randomization of disinfection processes. When a patient with C. difficile infection was discharged, environmental contamination in the patient's room was evaluated before and after disinfection. Environmental surfaces were sampled for C. difficile by use of moistened swabs; swab samples were cultured on selective plates and in broth. Both disinfectants were tested in vitro with a spore-carrier test; in this test, 2 types of material, vinyl polychloride (representative of the room's floor) and laminate (representative of the room's furniture), were experimentally contaminated with spores from 3 C. difficile strains, including the epidemic clone ribotype 027-North American pulsed-field gel electrophoresis type 1.Results.There were 748 surface samples collected (360 from rooms treated with hydrogen peroxide and 388 from rooms treated with hypochlorite). Before disinfection, 46 (24%) of 194 samples obtained in the rooms randomized to hypochlorite treatment and 34 (19%) of 180 samples obtained in the rooms randomized to hydrogen peroxide treatment showed environmental contamination. After disinfection, 23 (12%) of 194 samples from hypochlorite-treated rooms and 4 (2%) of 180 samples from hydrogen peroxide treated rooms showed environmental contamination, a decrease in contamination of 50% after hypochlorite decontamination and 91% after hydrogen peroxide decontamination (P < .005). The in vitro activity of 0.5% hypochlorite was time dependent. The mean (±SD) reduction in initial log10 bacterial count was 4.32 ± 0.35 log10 colony-forming units after 10 minutes of exposure to hypochlorite and 4.18 ± 0.8 logl0 colony-forming units after 1 cycle of hydrogen peroxide decontamination.Conclusion.In situ experiments indicate that the hydrogen peroxide dry-mist disinfection system is significantly more effective than 0.5% sodium hypochlorite solution at eradicating С difficile spores and might represent a new alternative for disinfecting the rooms of patients with C. difficile infection.

scholarly journals Use of Plant Extracts in the Control of Post-Harvest Fungal Rots in Apples

2019 ◽  
Vol 1 (3) ◽  
Author(s):  
EL ALAMI Nabila ◽  
EL ATTARI Soufiyan
Keyword(s):  
Plant Extracts ◽  
Pathogen Resistance ◽  
Economic Losses ◽  
Consumer Health ◽  
Higher Plant ◽  
New Approach ◽  
Post Harvest ◽  
In Situ Experiments

Different fungi alter apples in the post-harvest period, causing considerable economic losses and risks to consumer health due to the mycotoxins that some of these fungi produce. The control of these fungal alterations in apples is mainly dependent on the use of chemical fungicides, the effectiveness of which has been well proven. However, this use is subject to restrictions due to growing concerns about risks to human health and the environment and the continued development of pathogen resistance to commonly used fungicides. A new approach to control post-harvest fungi has been implemented through the application of plant extract.It is estimated that there are more than 250,000 higher plant species on Earth that can be evaluated for their antimicrobial bioactive chemical compounds. In recent decades, researchers have evaluated plant extracts and essential oils against fungi responsible for post-harvest apple rot. Interesting results have been obtained. The purpose of this project is to summarize and discuss the results of in vitro and in situ experiments of different literatures concerning the effects of compounds derived from plants on the control of fungi responsible for rotting apples in storage.

scholarly journals Influence of condensation domains on activity and specificity of adenylation domains

2021 ◽  
Author(s):  
Janik Kranz ◽  
Sebastian L. Wenski ◽  
Alexnder A. Dichter ◽  
Helge B. Bode ◽  
Kenan A. J. Bozhueyuek
Keyword(s):  
Structural Features ◽  
Peptide Synthetases ◽  
In Situ Experiments ◽  
The Subject ◽  
New Perspective ◽  
Condensation Domain

Many clinically used natural products are produced by non-ribosomal peptide synthetases (NRPSs), which due to their modular nature should be accessible to modification and engineering approaches. While the adenylation domain (A) plays the key role in substrate recognition and activation, the condensation domain (C) which is responsible for substrate linkage and stereochemical filtering recently became the subject of debate - with its attributed role as a "gatekeeper" being called into question. Since we have thoroughly investigated different combinations of C-A didomains in a series of in vitro, in vivo, and in situ experiments suggesting an important role to the C-A interface for the activity and specificity of the downstream A domain and not the C domain as such, we would like to contribute to this discussion. The role of the C-A interface, termed 'extended gatekeeping', due to structural features of the C domains, can also be transferred to other NRPSs by engineering, was finally investigated and characterised in an in silico approach on 30 wild-type and recombinant C-A interfaces. With these data, we not only would like to offer a new perspective on the specificity of C domains, but also to revise our previously established NRPS engineering and construction rules.

scholarly journals Surface Deterioration of Indirect Restorative Materials

2020 ◽  
Vol 31 (3) ◽  
pp. 264-271
Author(s):  
Amanda Mahammad Mushashe ◽  
Isabelli Carolini Farias ◽  
Carla Castiglia Gonzaga ◽  
Leonardo Fernandes da Cunha ◽  
Jack Libório Ferracane ◽  
...  
Keyword(s):  
Surface Characteristics ◽  
Ceramic System ◽  
Resin Cements ◽  
Restorative Materials ◽  
Levene Test ◽  
Adhesive Cement ◽  
Hybrid Ceramic ◽  
In Situ Biodegradation

Abstract The objective of this work was to evaluate the effects of in vitro and in situ biodegradation on the surface characteristics of two resin cements and a hybrid ceramic system. One hundred and eighty specimens (4X1.5mm) of each material (Maxcem Elite, NX3 Nexus and Vita Enamic) were made and randomly distributed in twelve groups (n=15) according to the material and biodegradation method. The specimens were then submitted to the following challenges: storage in distilled water 37 ºC for 24 h or 7 days, storage for 7 days, at 37 ºC, in stimulated saliva or in situ. The in situ stage corresponded to the preparation of 15 intraoral palatal devices, used for 7 days. Each device presented 3 niches, where a sample of each materials was accommodated. Specimens from both saliva and in situ groups suffered a cariogenic challenge, corresponding to the application of a solution of 20% of sucrose, 10 times throughout each day. After each biodegradation method, the surface roughness (Ra), Vickers hardness (VHN) and scanning electron microscopy (SEM) analyzes were performed. The data collected were evaluated by Levene test, two-way ANOVA and Tukey`s test (α=5%). The in situ challenge promoted the greater biodegradation, regardless of the material. Regarding the materials, the Vita Enamic VHN was negatively affected by all biodegradation methods and the Nexus NX3 presented better performance than the self-adhesive cement tested. Therefore, within the conditions of this work, it was concluded that in situ biodegradation can affect negatively the surface characteristics of indirect restorative materials.

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