Abstract Aims The aim of the project was to determine the vertical variability of soil under the influence of deadwood (DWD) in a temperate forest ecosystem. Methods The laboratory analyses included ...soil layers of 0–5 cm, 5–10 cm, 10–20 cm and 20–40 cm, which were taken directly under the deadwood, as well as the forest litter layer and deadwood fragments. The control samples were taken 30 m away. Results The decomposition processes of deadwood are associated with a 55% increase in soil organic carbon (SOC) deposition to a depth of -40 cm and a 36% increase in total nitrogen (N) content compared to soils without deadwood. DWD significantly increases exchangeable cations, especially at a depth of -5 cm to -20 cm. Deadwood contains slightly more hydrogen (H +) and aluminum ions (Al 3+ ) than forest litter, but soil acidification is related to pedogenic processes rather than decomposition of deadwood in hyperacid forest soils. The soil surface under deadwood with a high degree of decomposition is characterised by a lower bulk density (BD) value than the soil where only forest litter was present. Conclusions Our studies suggest that the physicochemical properties of forest soils change under the influence of deadwood such that the deeper layers beneath the logs take on propertie8s that make them similar to the shallower layers without deadwood. To summarise, leaving deadwood in the forest has a positive effect on soil fertility by enriching the soil with nutrients (Ca 2+ , K + , Na + , less Mg 2+ ) and improving its physical properties.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The Bialowieza Primeval Forest (BF) is one of the well-known forests in Central Europe. The most common tree species in BF was Norway spruce (Picea abies (L.) H. Karst), comprising 26%. However, a ...mass dieback of spruce has occurred during recent years. The spruce dieback in Bialowieza Forest is directly caused by the spruce bark beetle. However, the mass appearance of this pest can be a consequence of global warming and drought. Changes in air temperature were presented and drought indices were calculated as follows: standardized precipitation index, Palmer drought severity index, climatic water balance and soil water storage deficit. The warming of the climate of Bialowieza from 1950 to 2015 is comparable to that observed throughout central Europe. The temperature increased by 1.27 °C. The occurrence of drought from 1950 to 1966 and from 1985 to 2015 had a similar frequency. From 1963 to 1966, the volume of removed deadwood from the managed part of Bialowieza Forest was 27 thousand m3 but from 2012 to 2016, the volume was more than one million m3.
Purpose
Skin and soft tissue infections are increasingly prevalent and often complicated by potentially fatal therapeutic hurdles, such as poor drug perfusion and antibiotic resistance. Delivery ...vehicles capable of versatile loading may improve local bioavailability and minimize systemic toxicities yet such vehicles are not clinically available. Therefore, we aimed to expand upon the use of glutathione-conjugated poly(ethylene glycol) GSH-PEG hydrogels beyond protein delivery and evaluate the ability to deliver traditional therapeutic molecules.
Methods
PEG and GSH-PEG hydrogels were prepared using ultraviolet light (UV)-polymerization. Hydrogel loading and release of selected drug candidates was examined using UV-visible spectrometry. Therapeutic molecules and GST-fusion protein loading was examined using UV-visible and fluorescent spectrometry. Efficacy of released meropenem was assessed against meropenem-sensitive and -resistant
P. aeruginosa
in an agar diffusion bioassay.
Results
For all tested agents, GSH-PEG hydrogels demonstrated time-dependent loading whereas PEG hydrogels did not. GSH-PEG hydrogels released meropenem over 24 h. Co-loading of biologic and traditional therapeutics into a single vehicle was successfully demonstrated. Meropenem-loaded GSH-PEG hydrogels inhibited the growth of meropenem-sensitive and resistant
P. aeruginosa
isolates.
Conclusion
GSH ligands within GSH-PEG hydrogels allow loading and effective delivery of charged therapeutic agents, in addition to biologic therapeutics.
Graphical abstract
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We investigated the occurrence and pathogenicity of
Beauveria
spp. (Hypocreales: Cordycipitaceae) in forest soils in Poland, in outbreak areas of cockchafers (Coleoptera: Scarabaeidae):
Melolontha
...melolontha
L. and
M. hippocastani
F. We also examined the occurrence of
Beauveria
in relation to soil pH.
Beauveria
spp. isolates were characterised at species and genotype levels using ITS and microsatellite markers.
Beauveria
spp., which were detected at over 80% of sites, were sensitive to pH, preferring neutral or alkaline soils. This suggests that the acidity of forest soils in Poland can affect their efficacy as biological control agents (BCAs).
B. brongniartii
(Sacc.) Petch as a pathogen of cockchafers occurred at 41% of sites, but often at densities below the threshold values for infection, and it infected only 1.3% of cockchafer grubs. Our results suggest that
B. brongniartii
genotype isolated from cockchafers in forest soils can potentially expand the pool of BCAs in this environment.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Raised bogs dominated by the vegetation association
Ledo
-
Sphagnetum magellanici
Sukopp 1959 em. Neuhäusl 1969 are a valuable and ecologically important plant community that occurs in Central ...Europe. They develop in impervious depressions with precipitation as the only water source, and are particularly sensitive to drainage, climate change, eutrophication and overgrowing by trees and shrubs. The high pressure of threat justifies taking protective measures. This research focused on the effects of the removal of birch from two bogs, which were dominated by two birch species (
Betula pubescens
,
B. pendula
) and also included stands of Scots pine (
Pinus sylvestris
); the bogs are located in northeastern Poland and showed signs of drying. The trees were removed in early spring 2008. To capture the response to tree cutting, vegetation monitoring was performed for 7 years. The results were compared to pre-cutting environmental conditions (precipitation, temperature, air transpiration). At the first site, which was drained at the beginning of the twentieth century, the ground water level initially decreased; then, from 2010 onwards, the level stabilised and exhibited a negative correlation with the average annual air temperature. While the second site exhibited no significant differences in the ground water table, a correlation with the average annual rainfall was found. At both sites, there was an increase in the coverage of species appropriate for raised bogs,
Oxycocco
-
Sphagnatea
Br.-Bl. et R. Tx. 1943, whereas only the second site had significant coverage of these species. These actions improved the habitat conditions and initiated the process of raised bog restoration at that site because
Oxycocco
-
Sphagnatea
species cover and frequency increased.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Natural products remain an important source of drug candidates, but the difficulties inherent to traditional isolation, coupled with unacceptably high rates of compound rediscovery, limit the pace of ...natural product detection. Here we describe a reactivity-based screening method to rapidly identify exported bacterial metabolites that contain dehydrated amino acids (i.e., carbonyl- or imine-activated alkenes), a common motif in several classes of natural products. Our strategy entails the use of a commercially available thiol, dithiothreitol, for the covalent labeling of activated alkenes by nucleophilic 1,4-addition. Modification is easily discerned by comparing mass spectra of reacted and unreacted cell surface extracts. When combined with bioinformatic analysis of putative natural product gene clusters, targeted screening and isolation can be performed on a prioritized list of strains. Moreover, known compounds are easily dereplicated, effectively eliminating superfluous isolation and characterization. As a proof of principle, this labeling method was used to identify known natural products belonging to the thiopeptide, lanthipeptide, and linaridin classes. Further, upon screening a panel of only 23 actinomycetes, we discovered and characterized a novel thiopeptide antibiotic, cyclothiazomycin C.
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IJS, KILJ, NUK, PNG, UL, UM, UPUK
The article, while trying to avoid any strait apologetic approach to the religious problem of
miracle, considers it in the theological perspective. The theological interpretation seems to be
...necessary, as those aspects of the Judeo-Christian revelation that make it believable need to be
integrated into a broader and deeper outlook, into a broader epistemological and religious
framework for its proper understanding. The article consists of the following parts: “Voices of
Dictionary”, “Miracle as the Definitive Criterion of Revelation, “Miracle and its Dimensions”,
“Miracles as the Credibility of Faith”, “Miracles, Christology, Liberation”, “Functions of
Miracle”.
Acute bacterial skin and skin structure infections (ABSSSIs) confer a substantial burden on the healthcare system. Local antibiotic delivery systems can provide controlled drug release directly to ...the site of infection to maximize efficacy and minimize systemic toxicity. The purpose of this study was to examine the antibacterial activity of antibiotic-loaded glutathione-conjugated poly(ethylene glycol) hydrogels (GSH-PEG) against ABSSSIs utilizing an ex vivo porcine dermal explant model. Vancomycin- or meropenem-loaded GSH-PEG hydrogels at 3 different dose levels were loaded over 1 h. Drug release was monitored in vitro under submerged conditions, by the Franz cell diffusion method, and ex vivo utilizing a porcine dermis model. Antibacterial activity was assessed ex vivo on porcine dermis explants inoculated with Staphylococcus aureus or Pseudomonas aeruginosa isolates treated with vancomycin- or meropenem-loaded GSH-PEG hydrogels, respectively. Histological assessment of the explants was conducted to evaluate tissue integrity and viability in the context of the experimental conditions. A dose-dependent release was observed from vancomycin and meropenem hydrogels, with in vitro Franz cell diffusion data closely representing ex vivo vancomycin release, but not high dose meropenem release. High dose vancomycin-loaded hydrogels resulted in a >3 log
clearance against all S. aureus isolates at 48 h. High dose meropenem-loaded hydrogels achieved 6.5, 4, and 2 log
reductions in CFU/ml against susceptible, intermediate, and resistant P. aeruginosa isolates, respectively. Our findings demonstrate the potential application of GSH-PEG hydrogels for flexible, local antibiotic delivery against bacterial skin infections.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Acute bacterial skin and skin structure infections (ABSSSI) are a major burden on healthcare systems globally. Systemic treatment of ABSSSIs is often complicated by subtherapeutic drug concentrations ...at the infection site. Localized therapeutic delivery may overcome such barriers but current formulation approaches remain rigid and unable to accommodate flexible antimicrobial loading for ABSSSI treatment. Glutathione (GSH) is a tripeptide conventionally employed as a ligand for glutathione-S-transferase (GST) protein binding but also contains two anionic and one cationic functional groups. We explored the novel use of GSH as an association site for charge-bearing antimicrobials to provide an approach for selective antibiotic loading within polymeric hydrogels. Following polymerization of poly(ethylene glycol) hydrogels in the absence (PEG) or presence of GSH (GSH-PEG), electrostatic intermolecular forces were confirmed in the presence of GSH ligands. Placing blank hydrogels within drug solutions, increased loading of cationic and zwitterionic drugs was observed within GSH-PEG as compared to PEG hydrogels whereas anionic drugs were observed to load similarly in GSH-PEG and PEG hydrogels. Further flexibility in GSH-PEG hydrogel preparation was demonstrated by varying loading solution drug concentration to establish several dosage strengths while maintaining a rapid, clinically-relevant one hour loading period. Controlled release of antibiotics from GSH-PEG hydrogels was confirmed under submerged conditions and within a Franz diffusion system, mimicking topical application. Dose-dependent bacterial clearance was achieved with drug loaded GSH-PEG hydrogels using in vitro time kills and an ex vivo porcine dermis infection model. Moreover, the observed bacterial killing confirmed in silico mechanism-based modeling simulations, supporting the predictable and reliable nature of the GSH-PEG delivery phenomena. Conversely, human dermal fibroblast migration and proliferation was not significantly impaired in the presence of drug loaded or blank GSH-PEG hydrogels. Our findings successfully broadened the utility of GSH ligands beyond protein anchoring, providing flexible antibiotic association sites to achieve safe and effective release. These findings advance the concept of multi-functional delivery platforms in an effort to provide local therapeutic delivery tailored to patient needs in a timely and accessible manner.
Ultrasmall nanoparticles (NPs, <10 nm) have promise in cancer treatment, yet little is known about how NP physical properties influence penetration through solid tumors. To elucidate the role of NP ...size and structure, we prepared a series of sub-10 nm poly(amidoamine) (PAMAM) dendrimers and gold NPs (AuNP), and evaluated penetration in multicellular tumor spheroids (MCTS). Smaller generation 2 dendrimers (G2-NH2, 2.9 nm diameter) penetrated 2.5-fold deeper than larger G7-NH2 (8.1 nm) (P = 0.0005). Despite increased accumulation within MCTS, electrostatic cell interactions and ligand (folic acid, FA)-mediated targeting had minimal influence on penetration. NP rigidity played a minor role in penetration, with smaller rigid AuNP (2 nm) penetrating significantly more than larger AuNP (4 nm) (3-fold, P = 0.014; G2-NH2 vs. G4-NH2, 2.8-fold, P = 0.033). Our findings highlight the importance of rational NP design and provide design cues for tailored NP distributions within solid tumors.
Little is known regarding how nanoparticle (NP) physical properties influence tumor penetration. In a tumor model we evaluated sub-10 nm poly(amidoamine) dendrimers and gold NP penetration. Penetration was strictly size-dependent, within minimal influence of electrostatic interactions, ligand targeting, cellular uptake, and rigidity. We provide insights for tailored NP tumor distributions. Display omitted
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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