Idiopathic pulmonary fibrosis (IPF) is a complex lung disease with incompletely understood pathophysiology. Effectiveness of available medicines is limited and the need for new and improved therapies ...remains. Due to complexity of the disease, it is difficult to develop predictable in vitro models. In this study we have described precision-cut lung slices (PCLS) prepared from bleomycin treated mice as an in vitro model for testing of novel compounds with antifibrotic activity. We have shown that PCLS during in vitro incubation retain characteristics of bleomycin model with increased expression of fibrosis related genes ACTA2 (α-smooth muscle actin), COL1A1 (collagen 1), FN1 (fibronectin 1), MMP12 (matrix metalloproteinase 12) and TIMP1 (tissue inhibitor of metalloproteinases). To further evaluate PCLS as an in vitro model, we have tested ALK5 inhibitor SB525334 which was previously shown to attenuate fibrosis in in vivo bleomycin model and nintedanib which is the FDA approved treatment for IPF. SB525334 and nintedanib inhibited expression of fibrosis related genes in PCLS from bleomycin treated mice. In addition, comparable activity profile of SB525334 was achieved in PCLS and in vivo model. Altogether these results suggest that PCLS may be a suitable in vitro model for compound testing during drug development process.
Atypical weather and climate conditions during the spring and summer 2012th
were assumed to be the main reason for the aflatoxins contamination of corn
crops in Serbia. High humidity in spring, and ...summer temperatures above the
average contributed to the increased possibility of mycotoxins occurance in
cereals in the fields. As a consequence, at the begining of 2013th
contaminated corn used for dairy cows diet had negative impact on the safety
of cow milk. The routine laboratory control data revealed an increased
content of aflatoxin M1 in milk samples. Large number of raw milk and various
feedstuff samples were collected from February to April 2013th and were
analysed for the presence of aflatoxin M1 (AFM1) and aflatoxin B1
respectively. The collected samples were a part of enhanced self-control
plans of the large dairy farms. Quantitative competitive and sandwich types
of ELISA tests were used for the screening analysis of the feed and milk
samples. Confirmation of the positive results obtained by ELISA tests was
performed by UPLC-MS/MS method. Out of 281 samples of complete mixtures for
dairy cows, 67 samples (24%) contained aflatoxin B1 quantities higher than
the MRL of 0,005 mg/kg 4. Corn samples were also tested for the presence of
aflatoxin B1 revealing contamination of 22% above the MRL (0.03mg/kg).
Aflatoxin M1 content in the 934 positive milk samples ranged from 0,005- 1,25
?g/kg. The corresponding feed samples of sunflower meal, hay silage, corn
silage and sugar beet pulp were screening negative, with the content of
aflatoxin B1 less than 2 ?g/kg. The main source of aflatoxins were corn
samples, wholemeal and feed mixtures derived from contaminated corn. The
contamination peak was during March 2013, when 65% of milk samples contained
amounts of aflatoxin M1 higher than 0,05 ?g/kg, and 13% of milk samples
contained amounts higher than 0,5 ?g/kg.
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Objectives
The purpose of this study was to evaluate efficacy of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP) ...containing pastes among individuals with Sjögren’s syndrome (SS).
Materials and methods
Thirty patients were randomised into three groups: CPP-ACP, CPP-ACFP, and 0.05 % NaF to be used two times a day during a 28-day experimental period. Saliva was analysed for flow rate, pH, buffering capacity and mineral concentrations. Dental plaque was examined for pH. Following the formation of artificial carious lesion, participants wore enamel slabs for an in situ remineralisation study. Remineralisation potential was examined using scanning electron microscope (SEM) and energy dispersive spectroscopic (EDS) technique. SE microphotographs were subsequently analysed for area, diameter, perimeter, roundness and the number of enamel defects and percentage of tooth surface affected by defects.
Results
At the end of the experimental period, a slight increase of salivary pH could have been observed. No differences in mineral composition of saliva were noted. The use of CPP-ACP and CPP-ACFP contributed to a significant rise of plaque pH. Image analysis revealed excessive reduction of defects’ dimensions in the three experimental groups, and a decrease of the number of enamel defects in the CPP-ACP and CPP-ACFP groups. The EDS analysis did not show differences in Ca/P, Ca/O and P/O ratios in any of the treatment groups.
Conclusion
CPP-ACP and CPP-ACFP hold promise as remineralising agents for patients with SS.
Clinical relevance
Pastes containing CPP-ACP/CPP-ACFP show enhanced remineralisation potential compared with NaF mouthrinse in patients with SS.
In this work, epoxy hybrid materials were synthesized by addition of
thermoplastic segmented aliphatic polyurethanes with good elastic properties.
The modified epoxy samples were obtained by curing ...of previously homogenized
mixture of prepared polyurethane melts, epoxy resin and crosslinking agent
Jeffamine D-2000. The influence of different weight content of polyurethanes
(5, 10 and 15 wt. % compared to pure epoxy resin) as well the influence of
different hard segments of elastomers (20, 25 and 30 wt. %) on the curing of
modified epoxy systems was studied. The curing was followed by differential
scanning calorimetry (DSC), in dynamic regime from 30 to 300?C, at three
heating rates (5, 10 and 20?C/min). With the increase of hard segments
content of polyurethanes added in higher concentration (10 and 15 wt. %) into
epoxy matrix, the temperature of maximum ratio of curing was shifted to lower
values (from 205 to 179?C). Obtained DSC data were analyzed using two
integral methods (Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose) and one
differential kinetic model (Friedman). The significant differences were
observed in the second part of the epoxy curing (for the reaction degrees
higher than 60 %), where the values of activation energies remarkably
increase. The addition of polyurethane elastomers retarded the curing process
due to decreased mobility of reactant molecules caused by higher viscosity of
reaction mixture. By detailed analysis of determined kinetic parameters, it
is concluded that the influence of slow diffusion is more pronounced in the
presence of thermoplastic polycarbonate-based polyurethanes, which confirmed
their effect on the mechanism of epoxy curing. The highest tensile strength
and hardness showed the DGEBA modified with the polyurethane with highest
hard segment content. Increasing the hard segment content of polyurethane and
its concentration in matrix, the tensile strength of modified epoxy was
increased. The elongation at break of modified epoxy samples was
significantly improved by addition of polycarbonate-based polyurethanes with
low hard segment content, due to higher content of flexible soft segment
chains.
Background: Toxicological investigations of tissues of normally slaughtered
chickens were carried out to provide preliminary evaluation of the incidence
of OTA in chicken tissues (n=90). Majority of ...tissue samples were not found
to contain measurable amounts of OTA, while in general, the OTA levels found
in the analyzed tissue were low. Methods: The presence of OTA in tissue
samples was determined by HPLC-FL after liquid-liquid extraction procedure.
Method validation was performed according to the Commission Decision
2002/657/EC. Results: Of the 90 liver, kidney and gizzard samples originating
from chicken farms located in the different agricultural areas of Serbia, OTA
was reported in 23 (38.33%), 17 (28.3%) and 16 (26.6%) samples, respectively,
with levels ranging from 0.14 to 3.9 ng/g in liver, 0.1 to 7.02 ng/g in
kidneys and 0.25 to 9.94 ng/g in gizzard. None of the tissue samples
contained more than the maximum level (10 ng/g) recommended by the European
Commission. Conclusion: Low OTA results also suggested that chicken meat
available in the retail market is unlikely to pose an adverse health risk to
the consumers in respect to OTA toxicity.
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In this work, the attention was paid at the investigation of montmorillonite
dispersion in epoxy/amine systems due to improved final properties of the
nanocomposites. The influence of different ...montmorillonite content on the
kinetics of curing of epoxy/Jeffamine D-230 systems was followed by
differential scanning calorimetry (DSC). The curing of epoxy nanocomposites
was performed using dynamic regime at three different heating rates: 5, 10
and 20?C/min. Three isoconversional methods were applied: two integral
(Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose methods) and one differential
(Friedman method). The presence of montmorillonite (MMT) causes the beginning
of curing at lower temperatures. The shape of the DSC curves has been changed
by the addition of MMT, supporting the hypothesis of a change in the reaction
mechanism. For hybrids with 3 and 5 wt.% of MMT, the E? dependence is very
similar to those found for the reference system (epoxy/Jeffamine D-230) for
the curing degree less than 60%. The hybrid with 10 wt.% of MMT has lower
energy activation in regard to the referent system without montmorillonite.
Greater differences are observed in the second part of the reaction, where it
is known that the curing process is more controlled by diffusion (?>0.60).
The Ea value increases at the end of the reaction (??1), which was observed
for all systems, and is more pronounced in the presence of montmorillonite.
Recent trends in development of methods for screening and diagnosis of environmental pollutants such as dioxin and dioxin-like compounds utilizing chemical and bioanalytical detection, their ...principles and advantages/limitations are described in the present literature review. This study briefly summarizes methods for determination of dioxin and dioxin-like compounds based on chemical methods, biological receptor ligands, enzyme-inducing compounds and artificial peptides.
A combination of an alkyd resin with a melamine-formaldehyde resin gives a
cured enamel film with the flexibility of the alkyd constituent and the high
chemical resistance and hardness of the ...melamine resin at the same time. The
melamine resin is a minor constituent and plays the role of a crosslinking
agent. In this paper, alkyd resins of high hydroxyl numbers based on
trimethylolpropane, ricinoleic acid and phthalic anhydride were synthesized.
Two alkyds having 30 and 40 wt% of ricinoleic acid were formulated by
calculation on alkyd constant. Alkyds were characterized by FTIR and by the
determination of acid and hydroxyl numbers. Then synthesized alkyds were made
into baking enamels by mixing with melamine-formaldehyde resins (weight ratio
of 70:30 based on dried mass). Two types of commercial melamine resins were
used: threeisobutoxymethyl melamine-formaldehyde resin (TIMMF) and
hexamethoxymethyl melamine resin (HMMMF). Prepared alkyd/melamine resin
mixtures were cured in a differential scanning calorimeter (DSC) under
non-isothermal mode. Apparent degree of curing as a function of temperature
was calculated from the curing enthalpies. Kinetic parameters of curing were
calculated using Freeman-Carroll method. TIMMF resin is more reactive with
synthesized alkyds than HMMMF resin what was expected. Alkyd resin with 30
wt% of ricinoleic acid is slightly more reactive than alkyd with 40 wt% of
ricinoleic acid, probably because it has the high contents of free hydroxyl
and acid groups. The gel content, Tg, thermal stability, hardness, elasticity
and impact resistance of coated films cured at 150?C for 60 min were
measured. Cured films show good thermal stability since the onset of films
thermal degradation determined by thermogravimetric analysis (TGA) is
observed at the temperatures from 281 to 329?C. Films based on alkyd 30 are
more thermal stable than those from alkyd 40, with the same melamine resin.
The type of alkyd resin has no significant effect on the gel content and the
hardness of film. Hardness of cured film increases with increasing of Tg. The
values of the films elasticity are satisfied for all prepared samples and are
independent on the type of alkyd or melamine resin. The impact resistances of
coated films are very high.
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