The aim of this work was to assess the uptake of citrate-coated magnetite nanoparticles (NPs) by wheat plants and its effect on the bioaccumulation and toxicity of individual and joint Cd2+ and Cr6+ ...levels. Seven-day assays were conducted using quartz sand as the plant growth substrate. The endpoints measured were seed germination, root and shoot lengths, and heavy metal accumulation. Magnetite exhibited very low toxicity, regardless of the wheat seedling NP uptake and distribution into roots and shoots. The seed germination and shoot length were not sensitive enough, while the root length was a more sensitive toxicity endpoint. The root length of wheat seedlings exposed to individual metals decreased by 50% at 2.67mgCd2+kg−1 and 5.53mgCr6+kg−1. However, when magnetite NPs (1000mgkg−1) were added, the root length of the plants increased by 25 and 50%. Cd2+ and Cr6+ showed similar and noninteractive joint action, but strongly impaired the wheat seedlings. In contrast, an interactive infra-additive or antagonistic effect was observed upon adding magnetite NPs. Thus, cadmium and chromium accumulation in vegetable tissues was considerately diminished and the toxicity alleviated.
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•We assessed the effect of nanomagnetite on heavy metal toxicity in wheat plants.•Citrate-coated magnetite nanoparticles (NPs) exerted very low toxicity to plants.•Cadmium was more toxic than chromium and toxicity was mitigated by magnetite NPs.•Cadmium and chromium had a similar and noninteractive joint action on plants.•Metals showed an interactive infra-additive joint effect by adding magnetite NPs.
Cobalt ferrite nanoparticles (NPs) have received increasing attention due to their widespread therapeutic and agricultural applicability. In the environmental field, dry powder- and ...ferrofluid-suspended cobalt ferrite NPs were found to be useful for removing heavy metals and metalloids from water, while diluted suspensions of cobalt ferrite NP have been promisingly applied in medicine. However, the potential toxicological implications of widespread exposure are still unknown. Since cobalt ferrite NPs are considered residual wastes of environmental or medical applications, plants may serve as a point-of-entry for engineered nanomaterials as a result of consumption of these plants. Thus, the aim of this study was to assess the effects of dry powder and fresh cobalt ferrite NP on wheat plants. Seven-day assays were conducted, using quartz sand as the plant growth substrate. The toxicity end points measured were seed germination, root and shoot lengths, total cobalt (Co) and iron (Fe) accumulation, photosynthetic pigment production, protein (PRT) production, and activities of catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (GPX). Increasing total Co and Fe in plant tissues indicated that wheat plants were exposed to cobalt ferrite NP. Seed germination and shoot length were not sufficiently sensitive toxicity end points. The effective concentration (EC
50
) that diminished root length of plants by 50% was 1963 mg/kg for fresh ferrite NPs and 5023 mg/kg for powder ferrite NP. Hence, fresh ferrite NPs were more toxic than powder NP. Plant stress was indicated by a significant decrease in photosynthetic pigments. CAT, APX, and GPX antioxidant enzymatic activity suggested the generation of reactive oxygen species and oxidative damage induced by cobalt ferrite NP. More studies are thus necessary to determine whether the benefits of using these NPs outweigh the risks.
Alzheimer's disease (AD) is the most common form of dementia and one of the major causes of disability and dependency in older people. Accumulating evidences link gut microbiota with different ...diseases and its relationship with neurodegenerative diseases is becoming most intriguing. This study was aimed to compare the gut microbiota of transgenic APP/PS1 (TG) mice, a well‐established deterministic mouse model of AD, with their C57BL/6 wild‐type (WT) littermates. Faecal samples were collected from 3‐, 6‐ and 24‐month‐old mice and analysed by pyrosequencing of the V1–V3 region of the bacterial 16S rRNA genes. Bacterial profiles were similar in all young mice (3 months old), and started to diverge so that 6‐month‐old WT and TG mice had different and more diverse microbiota. During ageing, Turicibacteriaceae (typical mice bacterial group) and Rikenellaceae increased in all groups, although total Bacteroidetes remained stable. TG mice were characterized by an increase in Proteobacteria after 6 months, particularly the genus Sutterella (Betaproteobacteria), interestingly also increased in autism disorder. Also, the inflammation related family Erysipelotrichaceae was more abundant in TG mice at 24 months compared to wild‐type control. In summary, AD pathology in mice shifts the gut microbiota towards profiles that share features with autism and inflammatory disorders.
Significance and Impact of the Study
Alzheimer's disease is a neurodegenerative disease and neuroinflammation in the central nervous system appears to have a pivotal role. Using the transgenic APP/PS1 (TG) mouse model, we successfully characterized how AD pathology shifted gut microbiota composition during ageing towards an inflammation related bacterial profile related to Proteobacteria and Erysipelotrichaceae and suggest that these changes could contribute to disease progression and severity. Microbiota‐targeted interventions could therefore represent a strategy to postpone disease symptoms.
Significance and Impact of the Study: Alzheimer's disease is a neurodegenerative disease and neuroinflammation in the central nervous system appears to have a pivotal role. Using the transgenic APP/PS1 (TG) mouse model, we successfully characterized how AD pathology shifted gut microbiota composition during ageing towards an inflammation related bacterial profile related to Proteobacteria and Erysipelotrichaceae and suggest that these changes could contribute to disease progression and severity. Microbiota‐targeted interventions could therefore represent a strategy to postpone disease symptoms.
We present the results of prompt optical follow-up of the electromagnetic counterpart of the gravitational-wave event GW170817 by the Transient Optical Robotic Observatory of the South Collaboration. ...We detected highly significant dimming in the light curves of the counterpart ( mag, mag, mag) over the course of only 80 minutes of observations obtained ∼35 hr after the trigger with the T80-South telescope. A second epoch of observations, obtained ∼59 hr after the event with the EABA 1.5 m telescope, confirms the fast fading nature of the transient. The observed colors of the counterpart suggest that this event was a "blue kilonova" relatively free of lanthanides.
Oil activity has generated severe problems of soil contamination. Different techniques have been employed for the removal of pollutants, which are mainly used separately as treatments, but if ...combined, removal could be improved. The aim of this study was to remove total petroleum hydrocarbons (TPH) from soil artificially contaminated with crude oil using Fenton oxidation followed by biostimulation with nutrients and oil palm bagasse (OPB) used as an amendment. Microcosm units of soil with hydrocarbons were treated with H
2
O
2
and Fe citrate at 30% humidity and 25 °C. Samples were taken at 0, 10, and 30 days. Each unit was then adjusted to a C:N:P ratio of 100:10:1, which is considered optimal for remediation of soils contaminated with petroleum hydrocarbons, and mixed with OPB at a ratio of 96:4, 30% humidity, and 25 °C. Samples were taken at 0, 10, 30, and 40 days. Physicochemical parameters, TPH, microbial population, and lipase and dehydrogenase activity were monitored. Slight TPH removal (20.3%), a decrease in enzymatic activities, and a reduction in bacterial population were observed with Fenton oxidation. In the case of the biostimulation-amendment treatment, TPH removal was of 55%, with an increase in enzymatic activities and microbial population.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
► When
Ψ
stem
<
−1.7
MPa half-inversed or completely inversed diurnal
P
p curves were recorded. ► This was reversible: normal
P
p curves were recorded within a few days after rewatering. ► ...Information on water stress was derived from the inversed
P
p curves. ► An early detection of water stress can be achieved with LPCP probes installed in the east part of the canopy. ► The LPCP probe is an advantageous alternative to the pressure chamber in hedgerow olive orchards.
The need for sophisticated irrigation strategies in fruit tree orchards has led to an increasing interest in reliable and robust sensor technology that allows automatic and continuous recording of the water stress of trees under field conditions. In this work we have evaluated the potential of the leaf patch clamp pressure (LPCP) probe for monitoring water stress in a 4-year-old ‘Arbequina’ hedgerow olive orchard with 1667
trees
ha
−1. The leaf patch output pressure (
P
p) measured by the LPCP probe is inversely correlated with the leaf turgor pressure (>50
kPa). Measurements of
P
p were made over the entire irrigation season of 2010 (April to November) on control trees, irrigated up to 100% of the crop water needs (ET
c), and on trees under two regulated deficit irrigation (RDI) strategies. The 60RDI trees received 59.2% of ET
c and the 30RDI trees received 29.4% of ET
c. In the case of the RDI trees the irrigation amounts were particularly low during July and August, when the trees are less sensitive to water stress. At severe water stress levels (values of stem water potential dropped below ca. −1.70
MPa; turgor pressure
<
50
kPa) half-inversed or completely inversed diurnal
P
p curves were observed. Reason for these phenomena is the accumulation of air in the leaves. These phenomena were reversible. Normal diurnal
P
p profiles were recorded within a few days after rewatering, the number depending on the level of water stress previously reached. This indicates re-establishment of turgescence of the leaf cells. Crucial information about severe water stress was derived from the inversed diurnal
P
p curves. In addition
P
p values measured on representative trees of all treatments were compared with balancing pressure (
P
b) values recorded with a pressure chamber on leaves taken from the same trees or neighbored trees exposed to the same irrigation strategies. Concomitant diurnal
P
b measurements were performed in June and September, i.e. before and after the period of great water stress subjected to RDI trees. Results showed close relationships between
P
p and
P
b, suggesting that the pressure chamber measures relative turgor pressure changes as the LPCP probe. Therefore the probe seems to be an advantageous alternative to the pressure chamber for monitoring tree water status in hedgerow olive tree orchards.
Dendritic cell-based (DC-based) vaccines are promising immunotherapies for cancer. However, several factors, such as the lack of efficient targeted delivery and the sources and types of DCs, have ...limited the efficacy of DCs and their clinical potential. We propose an alternative nanotechnology-based vaccine platform with antibacterial prophylactic abilities that uses gold glyconanoparticles coupled to listeriolysin O 91-99 peptide (GNP-LLO
), which acts as a novel adjuvant for cancer therapy. GNP-LLO
, when used to vaccinate mice, exhibited dual antitumour activities, namely, the inhibition of tumour migration and growth and adjuvant activity for recruiting and activating DCs, including those from melanoma patients. GNP-LLO
nanoparticles caused tumour apoptosis and induced antigen- and melanoma-specific cytotoxic Th1 responses (P ≤ 0.5). We propose this adjuvant nanotherapy for preventing the progression of the first stages of melanoma.
► Application of process-based models in irrigation scheduling. ► Hydraulic limitations by soil and plant evaluated. ► Hydraulic and non-hydraulic signals in the control of transpiration quantified.
...We applied two process-based models in a hedgerow olive orchard with the aim of understanding the limitations and mechanisms behind the control of transpiration in olive trees under drip irrigation. One model is based on the biophysics of water flow through the porous media of soil and xylem. The other is a hydromechanical model based on the observed dependence of stomatal aperture on whole-plant and epidermis water relations. The experiments were made in a hedgerow olive orchard (1667treesha−1) planted with 5-year-old ‘Arbequina’ trees. Measurements were made in control trees irrigated to replace 100% of the crop water needs, and in trees under regulated deficit irrigation (RDI) strategy, in which irrigation replaced ca. 30% of the control. Soil physical properties, root distribution, leaf area, sap flow, leaf osmotic pressure and key variables of leaf gas exchange and water status were measured and models were applied. Results show how in our orchard, with a shallow root distribution and very coarse soil, most of the limitation to transpiration was imposed by the hydraulics of the rhizosphere. The model shows how this limitation was related to the ratio of root to leaf area, and how this ratio can be managed by canopy pruning or by changing the number of drippers. Likewise, osmotic adjustment occurred similarly in both irrigation treatments, despite differences found on leaf water potential. Water stress largely affected plant hydraulic conductivity of RDI trees. A potential involvement of regulating signals, other than purely hydraulics, was evident in both treatments, although our data suggests that these signals were not regulated by the soil water status only.
We used sap flow and trunk diameter measurements for assessing water stress in a high-density ‘Arbequina’ olive orchard with control trees irrigated to replace 100 % of the crop water needs, and ...60RDI and 30RDI trees, in which irrigation replaced ca. 60 and 30 % of the control, respectively. We calculated the daily difference for both tree water consumption (
) and maximum trunk diameter (
D
MXTD
) between RDI trees and control trees. The seasonal dynamics of
agreed reasonably well with that of the stem water potential. We identified peculiarities on the response
to changes in water stressing conditions, which must be taken into account when using the index. An analysis of the water stress variability in the orchard is required for choosing the instrumented trees. The reliability of the
D
MXTD
index was poorer than that of
. The maximum daily shrinkage (MDS) was not a reliable water stress indicator.
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