146 research outputs found

    Hydroponics as a valid tool to assess arsenic availability in mine soils

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    The low solubility of As in mine soils limits its phytoavailability. This makes the extrapolation of data obtained under hydroponic conditions unrealistic because the concentration in nutrient solution frequently overexposes plants to this metalloid. This work evaluates whether As supply in hydroponics resembles, to some extent, the As phytoavailable fraction in soils and the implications for phytoremediation. Phytotoxicity of As, in terms of biomass production, chlorophyll levels, and As concentrations in plants, was estimated and compared in both soils and hydroponics. In order for hydroponic conditions to be compared to soil conditions, plant exposure levels were measured in both cultures. Hydroponic As concentration ranging from 2-8 μM equated to the same plant organ concentrations from soils with 700-3000 mg kg-1. Total and extractable As fractions exceeded those values, but As concentrations in pore water were bellow them. According to our results (i) hydroponics should include doses in the range 0-10 μM As to allow the extrapolation of the results to As-polluted soils, and (ii) phytoextraction of As in mining sites will be limited by low As phytoavailabilityThis study was supported by the Spanish Ministry of Education and Science, project CTM 2007-66401-CO2/TECNO, and by Comunidad de Madrid, project S-0505/AMB/029

    Virus en Endodoncia

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    La infección endodóntica es la infección que afecta al sistema de conductos radiculares y, sin duda, es el principal agente etiológico de las periodontitis apicales. Además, de las bacterias patógenas endodónticas, se ha buscado en los últimos años asociar la presencia de virus en distintos tipos de patología endodóntica. Los virus que más se han buscado y asociado son los pertenecientes a la familia herpesvirus, los cuales se han encontrado presentes en patologías periapicales principalmente. Se ha buscado además, relacionar su presencia a patologías que cursan con mayor sintomatología, o que presentan a la imagen radiográfica destrucciones óseas periapicales mayores. El rol de los virus en las lesiones apicales de origen endodóntico está aún poco claro, se habla de efectos acumulativos a los de las bacterias, además de posibles inmunosupresiones locales que favorecerían el crecimiento y el efecto de estas última

    Low-level laser therapy in patients with Burning Mouth Syndrome : a double-blind, randomized, controlled clinical trial

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    Evaluate the effect of LLLT in the treatment of burning mouth syndrome (BMS). Twenty-one BMS patients were randomly assigned to two groups: 12 in the laser group (LG) and 9 in the control group (CG). Patients in the LG underwent 2-week sessions of LLLT for 4 weeks. The spot tip area of this tool is 0.088cm2, semi-conductor GaAlAs, with a wavelength of 808nm ±5nm (infrared), 200 mW output power, 1.97W/cm2 of power density, 3 J energy per point and application time 15 seconds per point. LLLT was applied punctually, in continuous emissions, on each of the sites where there was a symptom. Symptoms were evaluated with a visual analogue scale (VAS) and patient psychological profiles were assessed using the Hospital Anxiety-Depression Scale. No side effects were recorded. Statistical analysis was carried out via ANOVA and logistic regression analysis. The initial VAS score mean was 8.9 for the LG and 8.3 for the CG (p >0.05). After the eighth session the VAS score was 5.5 and 5.8 respectively, and at two months it was 4.7 and 5.1 respectively. Improvement variables were established by dichotomizing the pain scales. We obtained levels of significance for the improvement variable for the LG at the two-month follow-up (p=0.0038) and for the univariate analysis of the treatment. The improvement was marginally significant in the multivariant analysis of: dry mouth, dysgeusia, pain and the treatment (p=0.0538). LLLT may be an alternative treatment for the relief of oral burning in patients with BMS

    Analysis of Tag Loss Ratio in dynamic RFID systems

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    Abstract. Radio Frequency Identification (RFID) systems promise a revolution in logistics and inventory applications. By means of wireless communication, a master device can detect and identify nearby electronic tags. Traditionally, the performance of RFID systems and their identification protocols has been analyzed for static configurations, that is, without considering incoming or outgoing tags, but just a fixed number of initially unidentified tags. However, many real scenarios cannot be consistently modeled that way. In this work we introduce a Markov model which allows us to study a dynamic RFID tag scenario, where a flow of tags is considered. This model can be used to compute the Tag Loss Ratio, which measures the ratio of outgoing unidentified tags to the incoming tags in the system, which is a critical metric in dynamic configurations. The analysis is carried out for two families of protocols used as medium access control in RFID, Framed Slotted Aloha and non-persistent CSMA. With the aim of validating the analysis predictions, we get simulation results, by means of a simulator. We evaluate a scenario similar to a real application, i.e. a mail control system based on RFID

    Memantine loaded PEGylated biodegradable nanoparticles for the treatment of glaucoma

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    Glaucoma is a multifactorial neurodegenerative disease associated with retinal ganglion cells (RGC) loss. Increasing reports of similarities in glaucoma and other neurodegenerative conditions have led to speculation that therapies for brain neurodegenerative disorders may also have potential as glaucoma therapies. Memantine is an N-methyl-d-aspartate (NMDA) antagonist approved for Alzheimer's disease treatment. Glutamate-induced excitotoxicity is implicated in glaucoma and NMDA receptor antagonism is advocated as a potential strategy for RGC preservation. This study describes the development of a topical formulation of memantine-loaded PLGA-PEG nanoparticles (MEM-NP) and investigates the efficacy of this formulation using a well-established glaucoma model. MEM-NPs <200 nm in diameter and incorporating 4 mg mL−1 of memantine were prepared with 0.35 mg mL−1 localized to the aqueous interior. In vitro assessment indicated sustained release from MEM-NPs and ex vivo ocular permeation studies demonstrated enhanced delivery. MEM-NPs were additionally found to be well tolerated in vitro (human retinoblastoma cells) and in vivo (Draize test). Finally, when applied topically in a rodent model of ocular hypertension for three weeks, MEM-NP eye drops were found to significantly (p < 0.0001) reduce RGC loss. These results suggest that topical MEM-NP is safe, well tolerated, and, most promisingly, neuroprotective in an experimental glaucoma model

    Memantine loaded PLGA PEGylated nanoparticles for Alzheimer's disease: in vitro and in vivo characterization

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    Background: Memantine, drug approved for moderate to severe Alzheimer's disease, has not shown to be fully efective. In order to solve this issue, polylactic-co-glycolic (PLGA) nanoparticles could be a suitable solution to increase drug's action on the target site as well as decrease adverse efects. For these reason, Memantine was loaded in biodegradable PLGA nanoparticles, produced by double emulsion method and surface-coated with polyethylene glycol. MEM-PEG-PLGA nanoparticles (NPs) were aimed to target the blood-brain barrier (BBB) upon oral administra‑ tion for the treatment of Alzheimer's disease. Results: The production parameters were optimized by design of experiments. MEM-PEG-PLGA NPs showed a mean particle size below 200 nm (152.6±0.5 nm), monomodal size distribution (polydispersity index, PI<0.1) and negative surface charge (−22.4 mV). Physicochemical characterization of NPs confrmed that the crystalline drug was dispersed inside the PLGA matrix. MEM-PEG-PLGA NPs were found to be non-cytotoxic on brain cell lines (bEnd.3 and astrocytes). Memantine followed a slower release profle from the NPs against the free drug solution, allowing to reduce drug administration frequency in vivo. Nanoparticles were able to cross BBB both in vitro and in vivo. Behavio‑ ral tests carried out on transgenic APPswe/PS1dE9 mice demonstrated to enhance the beneft of decreasing memory impairment when using MEM-PEG-PLGA NPs in comparison to the free drug solution. Histological studies confrmed that MEM-PEG-PLGA NPs reduced β-amyloid plaques and the associated infammation characteristic of Alzheimer's disease. Conclusions: Memantine NPs were suitable for Alzheimer's disease and more efective than the free drug

    PP2A ligand ITH12246 protects against memory impairment and focal cerebral ischemia in mice

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    ITH12246 (ethyl 5-amino-2-methyl-6,7,8,9-tetrahydrobenzo[b][1,8] naphthyridine-3-carboxylate) is a 1,8-naphthyridine described to feature an interesting neuroprotective profile in in vitro models of Alzheimer's disease. These effects were proposed to be due in part to a regulatory action on protein phosphatase 2A inhibition, as it prevented binding of its inhibitor okadaic acid. We decided to investigate the pharmacological properties of ITH12246, evaluating its ability to counteract the memory impairment evoked by scopolamine, a muscarinic antagonist described to promote memory loss, as well as to reduce the infarct volume in mice suffering phototrombosis. Prior to conducting these experiments, we confirmed its in vitro neuroprotective activity against both oxidative stress and Ca2+ overload-derived excitotoxicity, using SH-SY5Y neuroblastoma cells and rat hippocampal slices. Using a predictive model of blood-brain barrier crossing, it seems that the passage of ITH12246 is not hindered. Its potential hepatotoxicity was observed only at very high concentrations, from 0.1 mM. ITH12246, at the concentration of 10 mg/kg i.p., was able to improve the memory index of mice treated with scopolamine, from 0.22 to 0.35, in a similar fashion to the well-known Alzheimer's disease drug galantamine 2.5 mg/kg. On the other hand, ITH12246, at the concentration of 2.5 mg/kg, reduced the phototrombosis-triggered infarct volume by 67%. In the same experimental conditions, 15 mg/kg melatonin, used as control standard, reduced the infarct volume by 30%. All of these findings allow us to consider ITH12246 as a new potential drug for the treatment of neurodegenerative diseases, which would act as a multifactorial neuroprotectant.Peer Reviewe

    Association between Use of Enhanced Recovery after Surgery Protocol and Postoperative Complications in Total Hip and Knee Arthroplasty in the Postoperative Outcomes Within Enhanced Recovery after Surgery Protocol in Elective Total Hip and Knee Arthroplasty Study (POWER2)

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    Importance: The Enhanced Recovery After Surgery (ERAS) care protocol has been shown to improve outcomes compared with traditional care in certain types of surgery. Objective: To assess the association of use of the ERAS protocols with complications in patients undergoing elective total hip arthroplasty (THA) and total knee arthroplasty (TKA). Design, Setting, and Participants: This multicenter, prospective cohort study included patients recruited from 131 centers in Spain from October 22 through December 22, 2018. All consecutive adults scheduled for elective THA or TKA were eligible for inclusion. Patients were stratified between those treated in a self-designated ERAS center (ERAS group) and those treated in a non-ERAS center (non-ERAS group). Data were analyzed from June 15 through September 15, 2019. Exposures: Total hip or knee arthroplasty and perioperative management. Sixteen individual ERAS items were assessed in all included patients, whether they were treated at a center that was part of an established ERAS protocol or not. Main Outcomes and Measures: The primary outcome was postoperative complications within 30 days after surgery. Secondary outcomes included length of stay and mortality. Results: During the 2-month recruitment period, 6146 patients were included (3580 women [58.2%]; median age, 71 [interquartile range (IQR), 63-76] years). Of these, 680 patients (11.1%) presented with postoperative complications. No differences were found in the number of patients with overall postoperative complications between ERAS and non-ERAS groups (163 [10.2%] vs 517 [11.4%]; odds ratio [OR], 0.89; 95% CI, 0.74-1.07; P =.22). Fewer patients in the ERAS group had moderate to severe complications (73 [4.6%] vs 279 [6.1%]; OR, 0.74; 95% CI, 0.56-0.96; P =.02). The median overall adherence rate with the ERAS protocol was 50.0% (IQR, 43.8%-62.5%), with the rate for ERAS facilities being 68.8% (IQR, 56.2%-81.2%) vs 50.0% (IQR, 37.5%-56.2%) at non-ERAS centers (P <.001). Among the patients with the highest and lowest quartiles of adherence to ERAS components, the patients with the highest adherence had fewer overall postoperative complications (144 [10.6%] vs 270 [13.0%]; OR, 0.80; 95% CI, 0.64-0.99; P <.001) and moderate to severe postoperative complications (59 [4.4%] vs 143 [6.9%]; OR, 0.62; 95% CI, 0.45-0.84; P <.001) and shorter median length of hospital stay (4 [IQR, 3-5] vs 5 [IQR, 4-6] days; OR, 0.97; 95% CI, 0.96-0.99; P <.001). Conclusions and Relevance: An increase in adherence to the ERAS program was associated with a decrease in postoperative complications, although only a few ERAS items were individually associated with improved outcomes
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