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1.
Plants (Basel) ; 12(12)2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37375953

RESUMEN

Grape production worldwide is increasingly threatened by grapevine trunk diseases (GTDs). No grapevine cultivar is known to be entirely resistant to GTDs, but susceptibility varies greatly. To quantify these differences, four Hungarian grape germplasm collections containing 305 different cultivars were surveyed to determine the ratios of GTDs based on symptom expression and the proportion of plant loss within all GTD symptoms. The cultivars of monophyletic Vitis vinifera L. origin were amongst the most sensitive ones, and their sensitivity was significantly (p < 0.01) higher than that of the interspecific (hybrid) cultivars assessed, which are defined by the presence of Vitis species other than V. vinifera (e.g., V. labrusca L., V. rupestris Scheele, and V. amurensis Rupr.) in their pedigree. We conclude that the ancestral diversity of grapes confers a higher degree of resilience against GTDs.

2.
Sci Total Environ ; 873: 162302, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-36822430

RESUMEN

Forest management integrating nature conservation aspects into timber production focuses increasingly on small-scale interventions. However, the ecological consequences of gap cuttings remain ambiguous in oak-dominated forests. In the Pilis Gap Experiment, we analyze how combinations of different gap shapes (circular and elongated), and gap sizes (150 m2 and 300 m2) affect the microclimate and biota of a mature sessile oak-hornbeam forest in Hungary. We first report the changes in direct and diffuse light, soil moisture, daily air and soil temperatures, and relative air humidity in the experimental cuttings in the vegetation season directly following their implementation. Diffuse light had a central maximum and a concentric pattern. Direct light was distributed along a north-south gradient, with maxima in northern gap parts. Soil moisture was determined by gap shape: it increased significantly in the center of circular gaps, with multiple local maxima in the southern-central parts of large circular gaps. Its pattern was negatively related to direct light, and larger spatial variability was present in circular than in elongated gaps. The daily mean air temperatures at 1.3 m increased in all, especially in large gaps. Soil and ground-level temperatures remained largely unchanged, reflecting on light and soil moisture conditions affecting evaporative cooling. Relative humidity remained unaltered. Even though the opening of experimental gaps changed microclimatic conditions immediately, effect sizes remained moderate. Gap size and gap shape were both important determinants of microclimate responses: gap size markedly affected irradiation increase, gap shape determined soil moisture surplus, while soil and air temperatures, and air humidity depended on both components of the gap design. We conclude that 150-300 m2 sized management-created gaps can essentially maintain forest microclimate while theoretically providing enough light for oak regeneration; and that the manipulation of gap shape and gap size within this range are effective tools of adaptive management.

3.
Sensors (Basel) ; 22(24)2022 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-36560311

RESUMEN

In this study, sonication with mild heat treatment was used to reduce the E. coli count in inoculated liquid whole egg, egg yolk and albumen. Ultrasonic equipment (20/40 kHz, 180/300 W) has been used for 30/60 min with a 55 °C water bath. The combination of sonication and low-heat treatment was able to reduce the concentration of E. coli from 5-log CFU × mL-1 below 10 CFU × mL-1 at 300 W, 40 kHz and 60 min of sonication in liquid egg products. The 60 min treatment was able to reduce the E. coli concentration below 10 CFU × mL-1 in the case of egg yolk regardless of the applied frequency, absorbed power or applied energy dose. The 30 min treatment of sonication and heating was able to reduce significantly the number of E. coli in the egg products, as well. Our results showed that sonication with mild heat treatment can be a useful technique to decrease the number of microorganisms in liquid egg products to a very low level. Near-infrared spectroscopy was used to investigate structural changes in the samples, induced by the combined treatment. Principal component analysis showed that this method can alter the C-H, C-N, -OH and -NH bonds in these egg products.


Asunto(s)
Escherichia coli , Espectroscopía Infrarroja Corta , Calor , Recuento de Colonia Microbiana , Huevos/análisis
4.
Polymers (Basel) ; 14(14)2022 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-35890570

RESUMEN

Thanks to the polymer revolution of the 20th century, plastics are now part of our everyday lives. We use plastics as naturally as if they had always been an integral part of our lives. However, in the recent past, we were still predominantly using wood, metal, and glass objects, which were replaced by plastic products at an explosive rate. In many cases, this replacement has resulted in products with better physical, chemical, or biological properties. The changeover was too rapid, and the consequences were not recognized in time. This is evidenced by the huge scale of plastic pollution worldwide today. It is therefore in the interests of the future of both humans and animals that we must pay particular attention to the direct and indirect environmental impact of plastics introduced in animal husbandry. Starting from the tetrafunctional initiator produced as the first step of my work, poly(n-butyll acrylate) star polymers of different molecular weights were synthesized by atom transfer radical polymerization, using the so-called "core first" method. The bromine chain end of the produced star polymers was replaced by an azide group using a substitution reaction. Propalgyl telechelic PEGs were synthesized as a result of lattice end modification of poly(ethylene glycol) with different molecular weights. The azidated star polymers were connected with propalgyl telechelic PEGs using Huisgen's "click" chemical process, and as a result of the "click" connection, amphiphilic polymer networks with several different structures were obtained.

5.
Front Nutr ; 9: 1011553, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36846024

RESUMEN

Modern consumer expectations have become highly diversified: they want more opportunities to meet diverse family needs (diversity of family members in age, gender, physical activity, etc. ,) and individual health goals with a huge variety of sensorial preferences. Our research is aimed to develop a protein-dense, highly bioactive, lactose- and whey protein-free beverage applying a central composite rotational design (CCRD) with 2 factors. For this purpose, an egg white-based beverage was flavored with mixed berries (factor A) and enriched with bovine collagen peptides (factor B). After suitable sample preparation, the rheological properties were investigated by an Anton Paar MCR 92 rheometer (with CC 27 system, and flow behavior was analyzed with a Herschel-Bulkley (H-B) model). The antioxidant capacity of samples was investigated by Ferric Reducing Antioxidant Power (FRAP) method, the total anthocyanin content was estimated based on a spectrophotometric method, and the total phenolic content was determined by the Folin Ciocalteu method. Our results are figured on response surfaces demonstrating that both factors and their interactions show a positive correlation with the examined parameters. Based on the CCRD, all investigated parameters are significantly influenced by at least one aspect and can be adequately estimated for further product development.

6.
Foods ; 10(10)2021 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-34681332

RESUMEN

Discrimination and species identification of meat has always been of paramount importance in the European meat market. This is often achieved using different conventional analytical methods but advanced sensor-based methods, such as the electronic tongue (e-tongue), are also gaining attention for rapid and reliable analysis. The aim of this study was to discriminate Angus, domestic buffalo, Hungarian Grey, Hungarian Spotted cattle, and Holstein beef meat samples from the chuck steak part of the animals, which mostly contained longissimus dorsi muscles, using e-tongue as a correlative technique with conventional methods for analysis of pH, color, texture, water activity, water-holding capacity, cooking yield, water binding activity, and descriptive sensory analysis. Analysis of variance (ANOVA) was used to determine significant differences between the measured quality traits of the five-meat species after analysis with conventional analytical methods. E-tongue data were visualized with principal component analysis (PCA) before classifying the five-meat species with linear discriminant analysis (LDA). Significant differences were observed among some of the investigated quality parameter. In most cases, Hungarian Grey was most different from the other species. Using e-tongue, separation patterns could be observed in the PCA that were confirmed with 100% recognition and 97.5% prediction of all the different meat species in LDA.

7.
Sci Rep ; 11(1): 20520, 2021 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-34654879

RESUMEN

To secure the ecosystem services forests provide, it is important to understand how different management practices impact various components of these ecosystems. We aimed to uncover how silvicultural treatments affected the ground-dwelling spider communities during the first five years of a forest ecological experiment. In an oak-hornbeam forest stand, five treatments, belonging to clear-cutting, shelterwood and continuous cover forestry systems, were implemented using randomised complete block design. Spiders were sampled by pitfall traps, and detailed vegetation, soil and microclimate data were collected throughout the experiment. In the treatment plots spider abundance and species richness increased marginally. Species composition changes were more pronounced and treatment specific, initially diverging from the control plots, but becoming more similar again by the fifth year. These changes were correlated mostly to treatment-related light intensity and humidity gradients. The patchy implementation of the treatments induced modest increase in both gamma and beta diversity of spiders in the stand. Overall, spiders gave a prompt and species specific response to treatments that was by the fifth year showing signs of relatively quick recovery to pre-treatment state. At the present fine scale of implementation the magnitude of changes was not different among forestry treatments, irrespective of their severity.

8.
Molecules ; 26(15)2021 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-34361851

RESUMEN

Non-destructive testing (NDT) for eggshell faults is highly important for the egg industry, as cracked eggs account for around 3% of total production. The most commonly used method at present, candling, is labor intensive, while computer vision systems are expensive and complicated. In this paper, we present a simple, yet efficient, novel method for eggshell crack detection by acoustic spectroscopy. Altogether, 693 sound recordings were evaluated by different classification methods. The results show a cross-validated 2.1% total classification error, with only 0.87% false positive rate, which is the crucial metric for fresh eggs. Adapting the developed method to an industrial setting may lead to a reliable, fast and cost-effective detection method.


Asunto(s)
Acústica , Pollos , Cáscara de Huevo , Huevos , Análisis Espectral , Animales
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 260: 119912, 2021 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-34015742

RESUMEN

The strength and geometry of adsorption of substituted phenylpyruvates on silver surface was studied by means of surface enhanced Raman spectroscopy (SERS) using silver sol. 2'-nitrophenylpyruvates were used as starting materials in a newly developed heterogeneous catalytic asymmetric cascade reaction to produce substituted quinoline derivatives. Substituents on the aromatic ring of the starting materials had significant influence on the yield of the desired quinoline derivatives. Product selectivity of the transformation of nitrophenylpyruvates were enhanced by the acid added. The geometry and the strength of the adsorption are assumed to play an important role in the outcome of this reaction, so we have tried to find correlation between the structure of adsorbed phenylpyruvates and their catalytic performance. Based on the results of our spectroscopic measurements, the enol form is predominant in the series of phenylpyruvates in solid form and methanol solutions. Stronger adsorption of phenylpyruvates in acidic media through oxygen atoms was indicated by the increased enhancement in the SERS spectrum. The nitro group of 2'-nitrophenylpyruvates has no direct role in the adsorption on Ag surface. This observation has explained why the hydrogenation of the keto group (presumably via the enol form) occurs preferentially and why the formation of the undesired indole derivatives requiring reduction of the nitro group is suppressed. The SERS behavior has helped to get a closer look on the first step of adsorption of starting materials contributing to a better understanding of the cascade reaction studied, thus providing a better flexibility in catalyst design.

11.
Sensors (Basel) ; 21(2)2021 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-33429975

RESUMEN

In this study, liquid egg, albumen, and egg yolk were artificially inoculated with E. coli. Ultrasound equipment (20/40 kHz, 180/300 W; 30/45/60 min) with a circulation cooling system was used to lower the colony forming units (CFU) of E. coli samples. Frequency, absorbed power, energy dose, and duration of sonication showed a significant impact on E. coli with 0.5 log CFU/mL in albumen, 0.7 log CFU/mL in yolk and 0.5 log CFU/mL decrease at 40 kHz and 6.9 W absorbed power level. Significant linear correlation (p < 0.001) was observed between the energy dose of sonication and the decrease of E. coli. The results showed that sonication can be a useful tool as a supplementary method to reduce the number of microorganism in egg products. With near-infrared (NIR) spectra analysis we were able to detect the structural changes of the egg samples, due to ultrasonic treatment. Principal component analysis (PCA) showed that sonication can alter C-H, C-N, -OH and N-H bonds in egg. The aquagrams showed that sonication can alter the properties of H2O structure in egg products. The observed data showed that the absorbance of free water (1412 nm), water molecules with one (1440 nm), two (1462 nm), three (1472 nm) and four (1488 nm) hydrogen bonds, water solvation shell (1452 nm) and strongly bonded water (1512 nm) of the egg samples have been changed during ultrasonic treatment.


Asunto(s)
Yema de Huevo , Escherichia coli , Animales , Pollos , Recuento de Colonia Microbiana , Huevos , Sonicación
12.
RSC Adv ; 11(6): 3713-3724, 2021 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-35424281

RESUMEN

Two polymorphs and a solvatomorph of a new dimethylammonium polytungstate-decakis(dimethylammonium) dihydrogendodecatungstate, (Me2NH2)10(W12O42)·nH2O (n = 10 or 11)-have been synthesized. Their structures were characterized by single-crystal X-ray diffraction and solid-phase NMR methods. The shape of the dodecatungstate anions is essentially the same in all three structures, their interaction with the cations and water of crystallization, however, is remarkably variable, because the latter forms different hydrogen-bonded networks, and provides a highly versatile matrix. Accordingly, the N-H⋯O and C-H⋯O hydrogen bonds are positioned in each crystal lattice in a variety of environments, characteristic to the structure, which can be distinguished by solid-state 1H-CRAMPS, 13C, 15N CP MAS and 1H-13C heteronuclear correlation NMR. Thermogravimetry of the solvatomorphs also reflect the difference and multiformity of the environment of the water molecules in the different crystal lattices. The major factors behind the variability of the matrix are the ability of ammonium cations to form two hydrogen bonds and the rigidity of the polyoxometalate anion cage. The positions of the oxygen atoms in the latter are favourable for the formation of bifurcated and trifurcated cation-anion hydrogen bonds, some which are so durable that they persist after the crystals are dissolved in water, forming ion associates even in dilute solutions. The H atom involved in furcated hydrogen bonds cannot be exchanged by deuterium when the compound is dissolved in D2O. An obvious consequence of the versatility of the matrix is the propensity of these compounds to form multiple polymorphs.

13.
Anal Bioanal Chem ; 412(19): 4619-4628, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32472144

RESUMEN

Extracellular vesicles (EVs) are lipid bilayer-bounded particles that are actively synthesized and released by cells. The main components of EVs are lipids, proteins, and nucleic acids and their composition is characteristic to their type and origin, and it reveals the physiological and pathological conditions of the parent cells. The concentration and protein composition of EVs closely relate to their functions; therefore, total protein determination can assist in EV-based diagnostics and disease prognosis. Here, we present a simple, reagent-free method based on attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy to quantify the protein content of EV samples without any further sample preparation. After calibration with bovine serum albumin, the protein concentration of red blood cell-derived EVs (REVs) were investigated by ATR-FTIR spectroscopy. The integrated area of the amide I band was calculated from the IR spectra of REVs, which was proportional to the protein quantity in the sample' regardless of its secondary structure. A spike test and a dilution test were performed to determine the ability to use ATR-FTIR spectroscopy for protein quantification in EV samples, which resulted in linearity with R2 values as high as 0.992 over the concentration range of 0.08 to 1 mg/mL. Additionally, multivariate calibration with the partial least squares (PLS) regression method was carried out on the bovine serum albumin and EV spectra. R2 values were 0.94 for the calibration and 0.91 for the validation set. The results indicate that ATR-FTIR measurements provide a reliable method for reagent-free protein quantification of EVs. Graphical abstract.


Asunto(s)
Eritrocitos/química , Vesículas Extracelulares/química , Proteínas/análisis , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Animales , Bovinos , Humanos , Indicadores y Reactivos , Análisis de los Mínimos Cuadrados , Albúmina Sérica Bovina/análisis
14.
Biol Futur ; 71(3): 209-222, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34554510

RESUMEN

Hybridization associated with polyploidization and apomixis is a frequent mechanism of speciation. Sorbus is a genus with ongoing hybridization resulting in a polyploid complex with different parental lineage. Triparens is the smallest hybridogenous subgenus of Sorbus so far known to comprise only two taxa, S. intermedia and S. × liljeforsii that combine the genomes of three taxa (S. aria agg., S. aucuparia and S. torminalis). To elucidate the origins of S. dacica, S. paxiana and S. tauricola, three new trigenomic candidates formerly believed to be of biparental origin with either S. aria agg. × S. aucuparia or S. aria agg. × S. torminalis lineage we combined data from HPLC and chloroplast DNA analysing additional 33 related taxa as well. We concluded that the 'torminalis-type' flavonoid profile and the 'aucuparia-type' plastid indicate the participation of both S. torminalis and S. aucuparia resulting in the formation of S. dacica, S. paxiana and S. tauricola. Sorbus aria agg. as the third ancestor and as a necessary link to meet genes of S. torminalis and S. aucuparia in one genome is obvious from morphological features (densely tomentose undersides of leaves). The tetraploid cytotypes and obligate pseudogamy of S. dacica and S. paxiana were determined by flow cytometry and are published here for the first time. The most probable evolutionary scenario for Triparens species is: 1. a diploid sexual S. aucuparia as pollen acceptor hybridized with a tetraploid apomictic taxon from the S. aria agg. producing a triploid apomictic taxon with 'aucuparia-type' plastid inherited maternally; 2. during a second crossing event this subgenus Soraria hybrid as maternal progenitor hybridized with the sexual diploid S. torminalis (providing gene(s) of apigenin O-glucuronide synthesis) forming a tetraploid Triparens hybrid with 'aucuparia-type' plastid and 'torminalis-type' flavonoids.


Asunto(s)
Especiación Genética , Hibridación Genética , Sorbus/genética , Sorbus/química , Sorbus/clasificación , Tetraploidía
15.
Ecol Appl ; 30(2): e02043, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31758609

RESUMEN

A stable below-canopy microclimate of forests is essential for their biodiversity and ecosystem functionality. Forest management necessarily modifies the buffering capacity of woodlands. However, the specific effects of different forestry treatments on site conditions, the temporal recovery after the harvests, and the reason for the contrasts between treatments are still poorly understood. The effects of four different forestry treatments (clear-cutting, retention tree group, preparation cutting, and gap-cutting) on microclimatic variables were studied within a field experiment in a managed oak-dominated stand in Hungary, before (2014) and after (2015-2017) the interventions by complete block design with six replicates. From the first post-treatment year, clear-cuts differed the most from the uncut control due to the increased irradiance and heat load. Means and variability of air and soil temperature increased, air became dryer along with higher soil moisture levels. Retention tree groups could effectively ameliorate the extreme temperatures but not the mean values. Preparation cutting induced slight changes from the original buffered and humid forest microclimate. Despite the substantially more incoming light, gap-cutting could retain the cool and humid air conditions and showed the highest increase in soil moisture after the interventions. For most microclimate variables, we could not observe any obvious trend within 3 yr. However, soil temperature variability decreased with time in clear-cuts, while soil moisture difference continuously increased in gap- and clear-cuts. Based on multivariate analyses, the treatments separated significantly based mainly on the temperature maxima and variability. We found that (1) the effect sizes among treatment levels were consistent throughout the years, (2) the climatic recovery time for variables appears to be far more than 3 yr, and (3) the applied silvicultural methods diverged mainly among the temperature maxima. Based on our study, the spatially heterogeneous and fine-scaled treatments of continuous cover forestry (gap-cutting, selection systems) are recommended. By applying these practices, the essential structural elements creating buffered microclimate could be more successfully maintained. Thus, forestry interventions could induce less pronounced alterations in environmental conditions for forest-dwelling organism groups.


Asunto(s)
Microclima , Quercus , Ecosistema , Agricultura Forestal , Bosques , Hungría , Árboles
16.
Chembiochem ; 20(12): 1578-1590, 2019 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-30720915

RESUMEN

Antimicrobial peptides (AMPs) kill bacteria by targeting their membranes through various mechanisms involving peptide assembly, often coupled with disorder-to-order structural transition. However, for several AMPs, similar conformational changes in cases in which small organic compounds of both endogenous and exogenous origin have induced folded peptide conformations have recently been reported. Thus, the function of AMPs and of natural host defence peptides can be significantly affected by the local complex molecular environment in vivo; nonetheless, this area is hardly explored. To address the relevance of such interactions with regard to structure and function, we have tested the effects of the therapeutic drug suramin on the membrane activity and antibacterial efficiency of CM15, a potent hybrid AMP. The results provided insight into a dynamic system in which peptide interaction with lipid bilayers is interfered with by the competitive binding of CM15 to suramin, resulting in an equilibrium dependent on peptide-to-drug ratio and vesicle surface charge. In vitro bacterial tests showed that when CM15⋅suramin complex formation dominates over membrane binding, antimicrobial activity is abolished. On the basis of this case study, it is proposed that small-molecule secondary structure regulators can modify AMP function and that this should be considered and could potentially be exploited in future development of AMP-based antimicrobial agents.


Asunto(s)
Antiinfecciosos , Péptidos Catiónicos Antimicrobianos , Suramina , Antiinfecciosos/química , Antiinfecciosos/farmacología , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Células Cultivadas , Dicroismo Circular/métodos , Escherichia coli , Humanos , Membrana Dobles de Lípidos/química , Estructura Secundaria de Proteína , Suramina/química , Suramina/farmacología
17.
Sci Rep ; 8(1): 14499, 2018 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-30266943

RESUMEN

Membrane-active, basic amphipathic peptides represent a class of biomolecules with diverse functions. Sequentially close protein segments also show similar behaviour in several ways. Here we investigated the effect of the lipid mediator lysophosphatidic acid (LPA) on the conformation of structurally disordered peptides including extracellular antimicrobial peptides (AMPs), and calmodulin-binding motifs derived from cytosolic and membrane target proteins. The interaction with associated LPA resulted in gain of ordered secondary structure elements, which for most cases were previously uncharacteristic of the particular peptide. Results revealed mechanism of the LPA-peptide interactions with regulation of the lipid on peptide conformation and oligomerization in a concentration-dependent manner involving (1) relocation of tryptophan residues into the lipid cluster, (2) multiple contacts between the binding partners dictated by complex driving forces, (3) multiple peptide binding to LPA associates with an affinity in the low micromolar range, and (4) selectivity for LPA compared with structurally related lipids. In line with recent findings showing endogenous molecules inducing structural changes in AMPs, we propose that accumulation of LPA in signalling or pathological processes might modulate host-defense activity or trigger certain processes by direct interaction with cationic amphipathic peptide sequences.


Asunto(s)
Péptidos Catiónicos Antimicrobianos/efectos de los fármacos , Lisofosfolípidos/farmacología , Pliegue de Proteína/efectos de los fármacos , Secuencia de Aminoácidos , Péptidos Catiónicos Antimicrobianos/química , Dicroismo Circular , Detergentes/farmacología , Liposomas , Micelas , Conformación Proteica , Estructura Secundaria de Proteína , Termodinámica , Triptófano/química
18.
Appl Radiat Isot ; 124: 32-37, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28314163

RESUMEN

In the new European Basic Safety Standard (EU-BSS), a new reference level for indoor radon concentration in workplaces has recommended that the annual average activity concentration of indoor radon shall not be higher than 300Bqm-3. This paper describes the radon concentration level in an underground workplace (manganese ore mine) over long time intervals (4 years). Several common radon monitors devices - including NRPB and Raduet (as a passive method based on CR-39), AlphaGUARD PQ 2000Pro, SARAD EQF3220, TESLA and Pylon WLX (as active methods) - were used for continuous radon measurements. The output results were used, first, to comprised the result of each device, based on conditions present in underground mines; Second, to have comprehensive measurements about all factors that cause workers exposure to radiation (each monitoring device specified for a unique measurement). The results indicate that the mine's staff had successful efforts to reach the strict requirement of the new EU-BSS, and the average annual radon activity concentrations during the working hours were below 300Bqm-3 in the investigated period. The paper presents the effective dose calculations; applying different equilibrium factors suggested by the literature and calculated basing on our measurements at the site, concluding that the differences could be about threefold.


Asunto(s)
Contaminantes Radiactivos del Aire/análisis , Manganeso , Minería , Radón/análisis , Contaminación del Aire Interior/análisis , Humanos , Hungría , Concentración Máxima Admisible , Exposición Profesional/análisis , Dosis de Radiación , Exposición a la Radiación/análisis , Monitoreo de Radiación/métodos
19.
Int J Pharm ; 517(1-2): 234-246, 2017 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-27931785

RESUMEN

A series of 14 cationic derivatives of poly(aspartic acid) i.e. cationic polyaspartamides with different (dialkylamino)alkyl and alkyl or hydroxyalkyl side groups was synthesized by nucleophilic addition on polysuccinimide. The resulting polyaspartamides have moderate amphiphilic properties. Relationships between the structure and ratio of side groups and in vitro properties of polyaspartamides, including their cytotoxic and membrane-damaging activity towards human cell lines, primary skin fibroblasts and erythrocytes, were established and discussed. Cationic polyaspartamides vary in their DNA-binding, condensing and nuclease-protecting characteristics depending on the concentration ratio of (dialkylamino)alkyl and alkyl or hydroxyalkyl side groups. Effective cell transfection was achieved upon polyaspartamide-mediated plasmid DNA delivery in serum-free medium in the presence of chloroquine. Effect of serum proteins adsorption onto polyaspartamide based polyplexes, and the role of concentration of polyplexes in culture medium in their colloidal stability and transfection process were demonstrated. Synthesized polyaspartamides are biocompatible and long-acting gene carriers, which are applied to cells after dilution and without washing, thus providing transfection level comparable to that of commercial transfection reagent.


Asunto(s)
Amidas/química , Amidas/farmacología , Transfección/métodos , Adsorción , Amidas/síntesis química , Ácido Aspártico/análogos & derivados , Ácido Aspártico/química , Ácido Aspártico/farmacología , Proteínas Sanguíneas/química , Membrana Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , ADN/química , Portadores de Fármacos , Eritrocitos/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Humanos , Péptidos/química , Péptidos/farmacología , Cultivo Primario de Células , Relación Estructura-Actividad
20.
Acta Biomater ; 49: 486-494, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27915021

RESUMEN

Poly(aspartic acid) (PASP) derivatives with adjustable pH-dependent solubility were synthesized and characterized to establish the relationship between their structure and solubility in order to predict their applicability as a basic material for enteric coatings. Polysuccinimide, the precursor of PASP, was modified with short chain alkylamines, and the residual succinimide rings were subsequently opened to prepare the corresponding PASP derivatives. Study of the effect of the type and concentration of the side groups on the pH-dependent solubility of PASP showed that solubility can be adjusted by proper selection of the chemical structure. The Henderson-Hasselbalch (HH) and the extended HH equations were used to describe the pH-dependent solubility of the polymers quantitatively. The estimate provided by the HH equation is poor, but an accurate description of the pH-dependent solubility can be found with the extended HH equation. The dissolution rate of a polymer film prepared from a selected PASP derivative was determined by fluorescence marking. The film dissolved rapidly when the pH was increased above its pKa. Cellular viability tests show that PASP derivatives are non-toxic to a human cell line. These polymers are thus of great interest as starting materials for enteric coatings. STATEMENT OF SIGNIFICANCE: Poly(amino acid) type biocompatible polymers were synthesized for future use as pharmaceutical film coatings. To this end, we tailored the pH-dependent solubility of poly(aspartic acid) (PASP). It was found that both the solubility and the pKa values of the modified PASP depended strongly on composition. Fluorescent marking was used to characterize the dissolution of a chosen PASP derivative. In acidic media only a negligible amount of the polymer dissolved, but dissolution was very fast and complete at the pH values that prevail in the small intestine. As a consequence, enteric coatings based on such PASP derivatives may be used for drug delivery in the gastrointestinal tract.


Asunto(s)
Péptidos/química , Ácido Aspártico/análogos & derivados , Ácido Aspártico/química , Línea Celular Tumoral , Supervivencia Celular , Humanos , Concentración de Iones de Hidrógeno , Modelos Teóricos , Espectroscopía de Protones por Resonancia Magnética , Solubilidad
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