Coated Hematite Nanoparticles Alleviate Iron Deficiency in Cucumber in Acidic Nutrient Solution and as Foliar Spray

Micronutrient iron (Fe) deficiency poses a widespread agricultural challenge with global implications. Fe deficiency affects plant growth and immune function, leading to reduced yields and contributing to the global "hidden hunger." While conventional Fe-based fertilizers are available, their efficacy is limited under certain conditions. Most recently, nanofertilizers have been shown as promising alternatives to conventional fertilizers. In this study, three nanohematite/nanoferrihydrite preparations (NHs) with different coatings were applied through the roots and shoots to Fe-deficient cucumber plants. To enhance Fe mobilization to leaves during foliar treatment, the plants were pre-treated with various acids (citric acid, ascorbic acid, and glycine) at a concentration of 0.5 mM. Multiple physiological parameters were examined, revealing that both root and foliar treatments resulted in improved chlorophyll content, biomass, photosynthetic parameters, and reduced ferric chelate reductase activity. The plants also significantly accumulated Fe in their developing leaves and its distribution after NHs treatment, detected by X-ray fluorescence mapping, implied long-distance mobilization in their veins. These findings suggest that the applied NHs effectively mitigated Fe deficiency in cucumber plants through both modes of application, highlighting their potential as nanofertilizers on a larger scale.

Iron uptake of etioplasts is independent from photosynthesis but applies the reduction-based strategy

Introduction

Iron (Fe) is one of themost important cofactors in the photosynthetic apparatus, and its uptake by chloroplasts has also been associated with the operation of the photosynthetic electron transport chain during reduction-based plastidial Fe uptake. Therefore, plastidial Fe uptake was considered not to be operational in the absence of the photosynthetic activity. Nevertheless, Fe is also required for enzymatic functions unrelated to photosynthesis, highlighting the importance of Fe acquisition by non-photosynthetic plastids. Yet, it remains unclear how these plastids acquire Fe in the absence of photosynthetic function. Furthermore, plastids of etiolated tissues should already possess the ability to acquire Fe, since the biosynthesis of thylakoid membrane complexes requires a massive amount of readily available Fe. Thus, we aimed to investigate whether the reduction-based plastidial Fe uptake solely relies on the functioning photosynthetic apparatus.

Methods

In our combined structure, iron content and transcript amount analysis studies, we used Savoy cabbage plant as a model, which develops natural etiolation in the inner leaves of the heads due to the shading of the outer leaf layers.

Results

Foliar and plastidial Fe content of Savoy cabbage leaves decreased towards the inner leaf layers. The leaves of the innermost leaf layers proved to be etiolated, containing etioplasts that lacked the photosynthetic machinery and thus were photosynthetically inactive. However, we discovered that these etioplasts contained, and were able to take up, Fe. Although the relative transcript abundance of genes associated with plastidial Fe uptake and homeostasis decreased towards the inner leaf layers, both ferric chelate reductase FRO7 transcripts and activity were detected in the innermost leaf layer. Additionally, a significant NADP(H) pool and NAD(P)H dehydrogenase activity was detected in the etioplasts of the innermost leaf layer, indicating the presence of the reducing capacity that likely supports the reduction-based Fe uptake of etioplasts.

Discussion

Based on these findings, the reduction-based plastidial Fe acquisition should not be considered exclusively dependent on the photosynthetic functions.

Influence of the urban environment on four mushroom species in the light of their elemental composition

The mushrooms are living organisms with excellent capability to adapt to the multiple challenges of their environment. Several species are well represented in urban green areas (parks, green spots, and recreation grounds). We investigated the influence of the urban environment over two saprotrophic (Bovista plumbea, Lycoperdon perlatum) and two mycorrhizal (Amanita rubescens, Suillus granulatus) species commonly present in urban parks of Cluj-Napoca, a major city of Romania. Three control sites close to the city were chosen. We determined 19 elements (Ag, Al, Ba, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, S, Si, Sr, Ti, and Zn) in the fruiting bodies of mushrooms and in soils by ICP OES technique. S. granulatus was the most sensible species to the urban pollution; this species accumulated 130 and 4.40 mg kg^-1 (dry weight) median concentrations of Al and Ni, respectively. The highest concentration of Ag, Cu and Fe was determined in B. plumbea (3.18, 83.7 and 141 mg kg^-1, respectively) and L. perlatum (4.68, 91.0 and 125 kg^-1, respectively) collected from the city. The saprotrophic species contained appreciably higher concentrations of Ag, Cu, Fe, Mg, P, and S than the mycorrhizal ones. Common feature of all four species was the higher Ag and Sr concentrations in the fruiting bodies of urban origin. Our results suggest that the unique defence mechanisms of the species might have higher impact over the elemental profile of the mushrooms than the soil properties. We propose L. perlatum and S. granulatus as suitable indicator species of the urban pollution with regard to inorganic pollutants.

Apoplast utilisation of nanohaematite initiates parallel suppression of RIBA1 and FRO1&3 in Cucumis sativus

Nanoscale Fe containing particles can penetrate the root apoplast. Nevertheless, cell wall size exclusion questions that for Fe mobilisation, a close contact between the membrane integrating FERRIC REDUCTASE OXIDASE (FRO) enzymes and Fe containing particles is required. Haematite nanoparticle suspension, size of 10-20 nm, characterized by ⁵⁷Fe Mössbauer spectroscopy, TEM, ICP and SAED was subjected to Fe utilisation by the flavin secreting model plant cucumber (Cucumis sativus). Alterations in the structure and distribution of the particles were revealed by ⁵⁷Fe Mössbauer spectroscopy, HRTEM and EDS element mapping. Biological utilisation of Fe resulted in a suppression of Fe deficiency responses (expression of CsFRO 1, 2 & 3 and RIBOFLAVIN A1; CsRIBA1 genes and root ferric chelate reductase activity). Haematite nanoparticles were stacked in the middle lamella of the apoplast. Fe mobilisation is evidenced by the reduction in the particle size. Fe release from nanoparticles does not require a contact with the plasma membrane. Parallel suppression in the CsFRO 1&3 and CsRIBA1 transcript amounts support that flavin biosynthesis is an inclusive Fe deficiency response involved in the reduction-based Fe utilisation of Cucumis sativus roots. CsFRO2 is suggested to play a role in the intracellular Fe homeostasis.

S-Methylmethionine Effectively Alleviates Stress in Szarvasi-1 Energy Grass by Reducing Root-to-Shoot Cadmium Translocation

S-methylmethionine (SMM) is a universal metabolite of higher plants derived from L-methionine that has an approved priming effect under different types of abiotic and biotic stresses. Szarvasi-1 energy grass (Elymus elongatus subsp. ponticus cv. Szarvasi-1) is a biomass plant increasingly applied in phytoremediation to stabilize or extract heavy metals. In this study, Szarvasi-1 was grown in a nutrient solution. As a priming agent, SMM was applied in 0.02, 0.05 and 0.1 mM concentrations prior to 0.01 mM Cd addition. The growth and physiological parameters, as well as the accumulation pattern of Cd and essential mineral nutrients, were investigated. Cd exposure decreased the root and shoot growth, chlorophyll concentration, stomatal conductance, photosystem II function and increased the carotenoid content. Except for stomatal conductance, SMM priming had a positive effect on these parameters compared to Cd treatment without priming. In addition, it decreased the translocation and accumulation of Cd. Cd treatment decreased K, Mg, Mn, Zn and P in the roots, and K, S, Cu and Zn in the shoots compared to the untreated control. SMM priming changed the pattern of nutrient uptake, of which Fe showed characteristic accumulation in the roots in response to increasing SMM concentrations. We have concluded that SMM priming exerts a positive effect on Cd-stressed Szarvasi-1 plants, which retained their physiological performance and growth. This ameliorative effect is suggested to be based on, at least partly, the lower root-to-shoot Cd translocation by the upregulated Fe uptake and transport.

Measuring peroxidasin activity in live cells using bromide addition for signal amplification

Peroxidasin (PXDN) is involved in the crosslinking of collagen IV, a major constituent of basement membranes. Disruption of basement membrane integrity as observed in genetic alterations of collagen IV or PXDN can result in developmental defects and diverse pathologies. Hence, the study of PXDN activity in (patho)physiological contexts is highly relevant. So far, measurements of PXDN activity have been reported from purified proteins, cell lysates and de-cellularized extracellular matrix. Here, for the first time we report the measurement of PXDN activity in live cells using the Amplex Red assay with a signal amplifying modification. We observe that bromide addition enhances the obtained signal, most likely due to formation of HOBr. Abrogation of signal amplification by the HOBr scavenger carnosine supports this hypothesis. Both, pharmacological inhibition as well as complementary genetic approaches confirm that the obtained signal is indeed related to PXDN activity. We validate the modified assay by investigating the effect of Brefeldin A, to inhibit the secretory pathway and thus the access of PXDN to the extracellular Amplex Red dye. Our method opens up new possibilities to investigate the activity of PXDN in (patho)physiological contexts.

Halochromic Behavior and Anticancer Effect of New Synthetic Anthocyanidins Complexed with β-Cyclodextrin Derivatives

Anthocyanidins, the aglycons of anthocyanins, are known, beyond their function in plants, also as compounds with a wide range of biological and pharmacological activities, including cytostatic effect against various cancer cells. The nature and position of the substituents in the flavylium cation is essential for such biological properties, as well as the equilibrium between the multistate of the different chemical species that are generated by the flavylium cation, including quinoidal base, hemiketal, and cis- and trans-chalcones. In this work, eight new flavylium derivatives were synthesized, characterized for confirmation of the structure by FT-IR and 2D-NMR, and investigated in vitro as possible cytostatic compounds against HCT116 and HepG2 cancer cells. The most active two compounds were explored for their halochromic properties that can influence the biological activity and subjected to molecular encapsulation in β-cyclodextrin derivatives in order to increase their solubility in water and bioavailability. The anticancer effect was influenced by the position (6-, 7-, or 8-) of the methoxy group in the β-ring of the methoxy-4′-hydroxy-3′-methoxyflavylium cation, while the study of the halochromic properties revealed the important role played by the chalcone species of the pH-dependent multistate in both the uncomplexed and inclusion complex forms of these anthocyanidins.

Altered element homeostasis and transmethylation ability in short-term polyphenol rich supplementation in hyperlipidemic animal model

Non-alcoholic fatty liver disease is one of the most common chronic liver diseases with unclarified pathomechanism and without evidence-proven therapy. Dietary polyphenols, targeting oxidative stress, are at the center of investigations. Our aim was to examine the effects of a polyphenol rich extract on metal element homeostasis and transmethylation ability in non-alcoholic fatty liver model. A ten-day rat model was used (control group, hyperlipidemic group with fat-rich diet, hyperlipidemic group with fat-rich diet and polyphenol supplementation, N = 8 in each group). The hyperlipidemic diet increased the concentration of the majority of the elements with significantly higher contents of B, Co, Cu, Fe, Mg, Mn, Na, Ni, P, Se, Si, and Zn in the liver. Further elevation of Al, Pb, and Sn concentrations could be observed in polyphenol supplemented animals. The polyphenol supplement unexpectedly decreased the transmethylation ability of the liver (132.00 vs. 114.15 vs. 92.25 HCHO μg g−1) further. The results emphasize the possible role of altered metal and non-metal element concentrations and decreased transmethylation ability in the pathomechanism of fatty liver disease. Dietary supplementation with natural compounds may have undesirable effect as well, there is the necessity to improve the efficacy of polyphenol formulations because of their low oral bioavailability.

Metronidazole does not show direct antioxidant activity in in vitro global systems

Metronidazole has been widely used topically and systemically for more than 50 years but data on its antioxidant properties are still incomplete, unclear and contradictory. Its antioxidant properties are primarily hypothesized based on in vivo results, therefore, studies have been performed to determine whether metronidazole has antioxidant activity in vitro. We used so-called global spectrophotometric and luminometric methods. Fe³⁺/Fe²⁺-reducing ability, hydrogen donor activity, hydroxyl radical scavenging property and lipid peroxidation inhibitory activity were investigated. Under the condition used, metronidazole has negligible iron-reducing ability and hydrogen donor activity. The hydroxyl radical scavenging capacity cannot be demonstrated. It acts as a pro-oxidant in the H₂O₂/^.OH-microperoxidase-luminol system, but it can inhibit the induced lipid peroxidation. According to our results, metronidazole has not shown antioxidant activity in vitro but can affect redox homeostasis by a ROS-independent mechanism due to its non-direct antioxidant properties.

Effect of the Microstructure of the Semiconductor Support on the Photocatalytic Performance of the Pt-PtOx/TiO2 Catalyst System

The influence of the semiconductor microstructure on the photocatalytic behavior of Pt-PtOx/TiO2 catalysts was studied by comparing the methanol-reforming performance of systems based on commercial P25 or TiO2 from sol-gel synthesis calcined at different temperatures. The Pt co-catalyst was deposited by incipient wetness and formed either by calcination or high-temperature H2 treatment. Structural features of the photocatalysts were established by X-ray powder diffraction (XRD), electron spin resonance (ESR), X-ray photoelectron spectroscopy (XPS), optical absorption, Raman spectroscopy and TEM measurements. In situ reduction of Pt during the photocatalytic reaction was generally observed. The P25-based samples showed the best H2 production, while the activity of all sol-gel-based samples was similar in spite of the varying microstructures resulting from the different preparation conditions. Accordingly, the sol-gel-based TiO2 has a fundamental structural feature interfering with its photocatalytic performance, which could not be improved by annealing in the 400-500 °C range even by scarifying specific surface area at higher temperatures.

Elemental composition of Russula cyanoxantha along an urbanization gradient in Cluj-Napoca (Romania)

How far-reaching is the influence of the urban area over the mineral composition of the Russula cyanoxantha mushroom? We studied the metal uptake behavior of this fungus relying on the soil properties. We sampled mushroom and soil from six forests according to an urbanization gradient, and two city parks in Cluj-Napoca (Romania). The elements were quantified using inductively coupled plasma - optical emission spectroscopy (ICP-OES). The concentrations of some elements differed significantly (p < 0.05) in the samples from the city (0.39 ± 0.35 mg kg^-1 for cadmium (Cd), 0.40 ± 0.19 mg kg^-1 for chromium (Cr), 69.1 ± 29.9 mg kg^-1 for iron (Fe), 10.9 ± 1.3 mg kg^-1 for manganese (Mn), 0.76 ± 0.45 mg kg^-1 for titanium (Ti) compared with the samples from the forests (3.15-14.1 mg kg^-1 Cd, < 0.18 mg kg^-1 for Cr, 22.6-34.5 mg kg^-1 for Fe, 15.9-19.1 mg kg^-1 for Mn, 0.19-0.36 mg kg^-1 for Ti). We observed a definite negative trend in the mineral accumulation potential of this fungus along the urbanization gradient. The fungus turned from a cadmium-accumulator to a cadmium-excluder. This highlights a positive environmental influence of the urbanization over the toxic metal uptake of R. cyanoxantha. The hypothesis, that the urban soil pollution would increase the metal content of the mushroom was disproved. The possible explanation might be the elevated carbonate content of the urban soil, which is known to immobilize the metals in the soil.

Data on elemental composition of Russula cyanoxantha along an urbanization gradient in Cluj-Napoca (Romania)

How far-reaching is the influence of the urban area over the mineral composition of the Russula cyanoxantha mushroom? To answer this question, we monitored the metal uptake behavior of this fungus relying on the soil properties. We sampled mushroom and soil from six forests according to an urbanization gradient, and two city parks in Cluj-Napoca (Romania). The elements were quantified using inductively coupled plasma - optical emission spectroscopy (ICP-OES). The concentrations of some elements differed significantly (p < 0.05) in the samples from the city (0.39 ± 0.35 mg kg-1 for cadmium (Cd), 0.40 ± 0.19 mg kg-1 for chromium (Cr), 69.1 ± 29.9 mg kg-1 for iron (Fe), 10.9 ± 1.3 mg kg-1 for manganese (Mn), 0.76 ± 0.45 mg kg-1 for titanium (Ti)) compared with the samples from the forests (3.15–14.1 mg kg-1 Cd, < 0.18 mg kg-1 for Cr, 22.6–34.5 mg kg-1 for Fe, 15.9–19.1 mg kg-1 for Mn, 0.19–0.36 mg kg-1 for Ti). We observed a definite negative trend in the mineral accumulation potential of this fungus along the urbanization gradient. The fungus turned from a cadmium-accumulator to a cadmium-excluder. This highlights a positive environmental influence of the urbanization over the toxic metal uptake of R. cyanoxantha. The hypothesis, that the urban soil pollution would increase the metal content of the mushroom was disproved. The possible explanation might be the elevated carbonate content of the urban soil, which is known to immobilize the metals in the soil.

Relationship between solid state structure and solution stability of copper(ii)–hydroxypyridinecarboxylate complexes

More acidic –OH groups increase the solution stability of copper(ii)–hydroxypyridinecarboxylate complexes and they lose the bridging role in cyclic dimer formation.

[Investigation of metal element content of some European and Far Eastern herbs]

INTRODUCTION

Metal elements and their excess intake have significant influence on general health.

AIM

There is only little information how Far Eastern herbs resemble European's regarding their purity and essential metal element content. The aim of the authors was to determine metal elements in different Chinese and European herbs and extracts.

METHOD

The studied European herbs included Calendula officinalis petals, Achillea millefolium, Epilobium parviflorum herba, Urtica dioica leaves, Crataegus monogyna flowers while Far Eastern herbs were Cordyceps sinensis, Ganoderma lucidum, Ginkgo biloba leaves, Panax ginseng and Curcuma longa roots. The analysis was performed using inductively coupled plasma optical emission spectroscopy.

RESULTS

There was no considerable difference in essential metal elements and the Ca:Mg concentration ratio between European and Far Eastern drugs and extracts.

CONCLUSIONS

The extracts are preferential metal element sources and their magnesium content are also advantageous, because of a shift of the Ca:Mg concentration ratio towards magnesium.

Remineralization of demineralized bone matrix in critical size cranial defects in rats: A 6-month follow-up study

The key drawback of using demineralized bone matrix (DBM) is its low initial mechanical stability due to the severe depletion of mineral content. In the present study, we investigated the long-term regeneration of DBM in a critical size bone defect model and investigated the remineralization after 6 months. Bone defects were created in the cranium of male Wistar rats which were filled with DBM or left empty as negative control. In vivo bone formation was monitored with computed tomography after 11, 19, and 26 weeks postoperatively. After 6 months, parietal bones were subjected to micro-CT. Mineral content was determined with spectrophotometric analysis. After 11 weeks the DBM-filled bone defects were completely closed, while empty defects were still open. Density of the DBM-treated group increased significantly while the controls remained unchanged. Quantitative analysis by micro-CT confirmed the in vivo results, bone volume/tissue volume was significantly lower in the controls than in the DBM group. The demineralization procedure depleted the key minerals of the bone to a very low level. Six months after implantation Ca, P, Na, Mg, Zn, and Cr contents were completely restored to the normal level, while K, Sr, and Mn were only partially restored. The remineralization process of DBM is largely complete by the 6th month after implantation in terms of bone density, structure, and key mineral levels. Although DBM does not provide sufficient sources for any of these minerals, it induces a faster and more complete regeneration process. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1336-1342, 2016.

Cisplatin administration influences on toxic and non-essential element metabolism in rats

Nowadays several papers deal with the effectiveness and side effects of metal complexes, especially cisplatin, in cancer therapy. The excretion of essential metal elements from the body is a serious problem in the treatment, but there are no data concerning the distribution and metabolism of toxic and nonessential elements. Therefore our aim was to study the concentration of some of these elements after treatment with cisplatin. Male Wistar rats (n=20, 175-190 g) were randomly divided into 2 groups (n=10/group). The control group received 1% (w/v) methyl cellulose at 10 mL/kg body weight, p.o. by gastric gavage twice daily for 14 days, while cisplatin was injected i.p. in a single dose of 6.5 mg/kg body weight. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used for measuring Al, B, Ba, Cr, Li, Ni, Pb, Pt, Sb, Si, Sn, Sr and V content in plasma, liver and kidney. Liver total scavenger capacity, diene conjugate content and malondialdehyde concentration were also determined. Cisplatin elevated the free radical reactions in the liver, although redox balance did not change significantly. According to the study it seems that the metabolism of Al, Ba, Cr, Ni, Pb, Sr were changed by the effect of cisplatin, and the most notable alterations were found for Al and Pb. Therefore, besides the toxic effect of and free radical induction by Pt, the side effects of increased levels of other toxic and non-essential elements have to be taken into consideration.

Polystyrene films as barrier layers for corrosion protection of copper and copper alloys

Dip-coated polystyrene layers of sub-micrometre thickness (85-500nm) have been applied on copper and copper alloys (aluminium brass, copper-nickel 70/30), as well as on stainless steel 304, and produced an effective barrier against corrosion and adhesion of corrosion-relevant microorganisms. According to the dynamic wettability measurements, the coatings exhibited high advancing (103°), receding (79°) and equilibrium (87°) contact angles, low contact angle hysteresis (6°) and surface free energy (31mJ/m(2)). The corrosion rate of copper-nickel 70/30 alloy samples in 3.5% NaCl was as low as 3.2μm/a (44% of that of the uncoated samples), and in artificial seawater was only 0.9μm/a (29% of that of the uncoated samples). Cell adhesion was studied by fluorescence microscopy, using monoculture of Desulfovibrio alaskensis. The coatings not only decreased the corrosion rate but also markedly reduced the number of bacterial cells adhered to the coated surfaces. The PS coating on copper gave the best result, 2×10(3)cells/cm(2) (1% of that of the uncoated control).

[Mineral content of some herbs and plant extracts with anti-inflammatory effect used in gastrointestinal diseases]

INTRODUCTION

In gastrointestinal diseases folk medicine usually recommends herbs and teas with antiinflammatory activities, especially mucilage and bitter agent containing plants. The use of stomatics as adjuvant therapy in medical practice is frequent.

AIM

The authors explored the mineral element content of some herbs, because mineral elements may have significant role in the development and treatment of gastrointestinal diseases, and a close connection between the presence or absence of mineral elements and inflammatory mediators was noted.

METHODS

The mineral content in Trigonellae foenugraeci semen, Farfarae folium et flos, Taraxaci radix and Cichorii radix and teas prepared from these herbs was determined using inductively coupled plasma optical emission spectrometry. The results were evaluated from nutritional and biomedical points of view.

RESULTS

Farfarae folium et flos tea was found to be a rich source of calcium, chromium, manganese and molybdenum. Trigonellae foenugraeci semen, Taraxaci radix and Cichorii radix displayed favourable calcium to magnesium ratio (1-1.5) and they contained other elements (manganese, iron, copper, zinc) which may have significant role in the immune defence system.

CONCLUSION

The beneficial therapeutic effect of the studied herbs may be related to their mineral element content.

[Effects of magnesium supplementation on calcium and magnesium levels, and redox homeostasis in normolipidemic and food-induced hyperlipidemic rats]

Magnesium supplementation is quite popular because of intention of health and healthy lifestyle. However, there is no information on the metabolic effects of magnesium supplementation in healthy people and in different diseases.

AIMS

Authors examined the effects of magnesium-malate on calcium, magnesium levels, and antioxidant parameters in normolipidemic and hyperlipidemic rats.

METHODS

Male Wistar rats (n = 40; 150-200 g) were divided into 4 groups (control, control-treated, hyperlipidemic, hyperlipidemic-treated). Rats in the control and control-treated groups were fed with normal diet, while hyperlipidemic and hyperlipidemic-treated groups were fed with fat rich diet (2% cholesterol, 20% sunflower oil, 0.5% cholic acid). After the 9-day-long diet the following parameters were measured: routine laboratory parameters with automatic analysator, metal content using ICP-OES, and redox-parameters using spectrophotometric and luminometric methods.

RESULTS

Magnesium-malate failed to produce significant changes in the measured parameters in control animals in most cases. Magnesium-malate decreased significantly serum glucose concentration, alkaline phosphatase and amylase activities in the hyperlipidemic group. Significantly low induced chemiluminescent activity was measured in the plasma and erythrocytes of hyperlipidemic group. The magnesium supplementation did not increase significantly magnesium concentration in different organs although the calcium/magnesium concentration ratio was decreased.

CONCLUSIONS

In control animals there was no significant change in the measured parameters in most cases after dietary supplementation with a large amount of magnesium for a short period of time, but magnesium supplementation affected the metal homeostasis, routine laboratory parameters and redox system in hyperlipidemic animals. Although several changes were favorable, it should be emphasized that magnesium supplementation must be applied watchfully particularly in metabolic diseases.

Comparison of stroke ward care versus mobile stroke teams in the Hungarian stroke database project

Although previous studies have proved that both stroke wards and mobile stroke teams are considerably better than non-specialized stroke care, an unresolved debate in vascular neurology is whether or not stroke wards provide better outcomes in some specific cases to stroke victims. Our prospective, multicenter, cohort study compared dedicated stroke wards versus specialist stroke team care at general hospital wards in 11 centers nationwide for 8743 consecutive stroke events during 18 months. Twenty-eight-day case-fatality rate was 12.6% at stroke wards versus 15.2% at stroke teams for all patients (P = 0.002), and stroke ward care also predicted better outcome when analyzed with multivariate logistic regression model (odds ratio 1.701; confidence interval: 1.025-2.822). Case-fatality rates were not significantly different in patients with modified Rankin score > or = 2 (case-fatality rate: 17.8% vs. 20.3%; P = 0.163), and over 60 (case-fatality rate: 14.8% vs. 15.9%; P = 0.250), however these patients were more probably at home after 4 weeks when treated at stroke wards (56.1% vs. 50.6%; P = 0.03, and 69.5% vs. 64.5%; P = 0.004). In our study, stroke ward admission provided lower case-fatality rate below 60 and for those independent prior to their strokes, and lower institutionalization over 60 and amongst previously dependent patients, when compared with stroke teams.

Hydrogen atom vs electron transfer in catecholase-mimetic oxidations by superoxometal complexes. Deuterium kinetic isotope effects

Dioximato-cobalt(II), -iron(II) and -manganese(II) complexes (1)-(6), acting as functional catecholase and phenoxazinone synthase models, exhibit a deuterium kinetic isotope effect predicted by theory (k4H/k4D < or = 3) in the catalytic oxidative dehydrogenation of 3,5-di-tert-butylcatechol and 2-aminophenol by O2. KIEs in the range of (k4H/k4D approximately 1.79-3.51) are observed with (1) and (2) as catalysts, pointing to hydrogen atom transfer in the rate-determining step from the substrate hydroxy group to the metal-bound superoxo ligand. Less significant KIEs (1.06-1.20) are exhibited by catalysts systems (3)-(6), indicating that proton-coupled electron transfer is the preferred route in those cases.