341 research outputs found

    Nitrogen release properties of urea–kaolinite controlled release fertilizer with chitosan binder

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    To reduce environmental and economic concerns of feeding crops with traditional fertilizers, a new type of controlled release fertilizer was prepared. In this study, urea–kaolinite was mixed with chitosan as a binder and then was granulated. The granules were incubated in water at room temperature for 30 days and urea release was measured in 5-days intervals using UV/Vis technique and through diacetylmonoxime (DAM) calorimetric method. In this study, different binder concentration was investigated. The results of UV–Vis spectroscopy illustrated that by increasing the chitosan concentration, nitrogen release decreased from 41.23 to 25.25 % after 24 h and from 77.31 to 59.27 % after 30 days incubation in water. By doing this, the prepared controlled release fertilizer (CRF) behaved according to the standard for CRFs. Compressive stress at break was measured for granules with different size and various concentration of chitosan. Results show that the force required to crush the granules is a function of the granule diameter and binder concentration

    Mineral potential modelling of orogenic gold systems in the granites-tanami Orogen, Northern Territory, Australia: A multi-technique approach

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    In this study we adopted fuzzy inference system (FIS), transformed predictor map-based random forest (RF) and feed-forward deep neural network (FF-DNN) approaches to mineral potential modelling (MPM) of the Granites-Tanami Orogen (GTO), Northern Territory, Australia, to (i) predict gold prospectivity, and (ii) compare the performance of these models to those previously generated in the study area. The current study, which utilized 19 predictor maps previously developed by Roshanravan et al. (2020) in the framework of a mineral systems approach, took into consideration the learnings gained and results obtained from previous approaches to modelling the gold potential of the GTO (Roshanravan et al., 2020: continuous fuzzy gamma, geometric average, data-driven index overlay and non-transformed predictor map-based RF; Roshanravan et al., 2021: cuckoo optimization algorithm). Importantly, our study area extending over > 46,000 km2 in the GTO, represents one of the few, if not the only, areas worldwide that has been subjected to eight different modelling techniques, an approach that delivered unique insights that cannot be achieved by utilizing a single technique. For example, our multi-technique approach enabled us to study what effect predictor maps may have on model performance and resulting mineral potential maps. In the case of data-driven MPM with RF, arguably-one of the most popular machine learning techniques, the effect of non-transformed (i.e., original) and transformed (i.e., derivative) predictor maps has never been evaluated simultaneously. To achieve this, we generated a transformed predictor map-based RF potential model with the aim of comparing it to the non-transformed predictor map-based RF model of Roshanravan et al. (2020). The FF-DNN and Mamdani-type FIS approaches to MPM were carried out specifically for the purpose of comparing and further investigating the modelling results. With respect to the Mamdani-type FIS, the concentration-area (C-A) fractal technique served to more objectively determine thresholds of the underlying mathematical functions, a novel approach that aids in reducing bias resulting from human input and expert opinion. The thresholded results demonstrate that the RF potential map generated with transformed predictor maps outperformed all other data-driven and continuous models. Overall, our multi-technique approach to MPM and the comparing and contrasting of a large set of resulting gold potential models, not only offered insights that helped to develop and calibrate new tools and techniques but also delivered what we believe are more robust gold exploration targets. As a result, we strongly recommend to using a multi-technique approach to MPM, which we hope will soon replace the currently accepted and widely utilized single-technique approach

    Mitochondrial dysfunction and oxidative stress in patients with chronic kidney disease.

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    Mitochondria abnormalities in skeletal muscle may contribute to frailty and sarcopenia, commonly present in patients with chronic kidney disease (CKD). Dysfunctional mitochondria are also a major source of oxidative stress and may contribute to cardiovascular disease in CKD We tested the hypothesis that mitochondrial structure and function worsens with the severity of CKD Mitochondrial volume density, mitochondrial DNA (mtDNA) copy number, BNIP3, and PGC1α protein expression were evaluated in skeletal muscle biopsies obtained from 27 subjects (17 controls and 10 with CKD stage 5 on hemodialysis). We also measured mtDNA copy number in peripheral blood mononuclear cells (PBMCs), plasma isofurans, and plasma F2-isoprostanes in 208 subjects divided into three groups: non-CKD (eGFR>60 mL/min), CKD stage 3-4 (eGFR 60-15 mL/min), and CKD stage 5 (on hemodialysis). Muscle biopsies from patients with CKD stage 5 revealed lower mitochondrial volume density, lower mtDNA copy number, and higher BNIP3 content than controls. mtDNA copy number in PBMCs was decreased with increasing severity of CKD: non-CKD (6.48, 95% CI 4.49-8.46), CKD stage 3-4 (3.30, 95% CI 0.85-5.75, P = 0.048 vs. non-CKD), and CKD stage 5 (1.93, 95% CI 0.27-3.59, P = 0.001 vs. non-CKD). Isofurans were higher in patients with CKD stage 5 (median 59.21 pg/mL, IQR 41.76-95.36) compared to patients with non-CKD (median 49.95 pg/mL, IQR 27.88-83.46, P = 0.001), whereas F2-isoprostanes did not differ among groups. Severity of CKD is associated with mitochondrial dysfunction and markers of oxidative stress. Mitochondrial abnormalities, which are common in skeletal muscle from patients with CKD stage 5, may explain the muscle dysfunction associated with frailty and sarcopenia in CKD Further studies are required to evaluate mitochondrial function in vivo in patients with different CKD stages

    Microbial Population Changes and Their Relationship with Human Health and Disease

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    Specific microbial profiles and changes in intestinal microbiota have been widely demonstrated to be associated with the pathogenesis of a number of extra-intestinal (obesity and metabolic syndrome) and intestinal (inflammatory bowel disease) diseases as well as other metabolic disorders, such as non-alcoholic fatty liver disease and type 2 diabetes. Thus, maintaining a healthy gut ecosystem could aid in avoiding the early onset and development of these diseases. Furthermore, it is mandatory to evaluate the alterations in the microbiota associated with pathophysiological conditions and how to counteract them to restore intestinal homeostasis. This review highlights and critically discusses recent literature focused on identifying changes in and developing gut microbiota-targeted interventions (probiotics, prebiotics, diet, and fecal microbiota transplantation, among others) for the above-mentioned pathologies. We also discuss future directions and promising approaches to counteract unhealthy alterations in the gut microbiota. Altogether, we conclude that research in this field is currently in its infancy, which may be due to the large number of factors that can elicit such alterations, the variety of related pathologies, and the heterogeneity of the population involved. Further research on the effects of probiotics, prebiotics, or fecal transplantations on the composition of the human gut microbiome is necessary.Ongoing research is funded by grant PI-0538-2017, Junta de Andalucía, Spain (to L.F.)

    Effect of foot reflexology on fatigue in patients undergoing hemodialysis: A sham-controlled randomized trial

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    Background and purpose: Fatigue is a common symptom in patients undergoing hemodialysis. Reflexology is a nursing intervention that could reduce fatigue. This study aimed at determining the effects of foot reflexology on fatigue in patients undergoing hemodialysis. Materials and methods: A clinical trial with before and after design was conducted in hemodialysis patients attending Imam-Ali and Iran-mehr clinic in Bojnurd, 2013. Using randomized sampling 78 patients were allocated into three groups: intervention, placebo, and control group. The patients in intervention group received foot reflexology, and simple foot reflexology without pressing certain parts of the foot was done in placebo group. The patients in control group received only routine care. Piper Fatigue Scale was used to measure fatigue level before and after the intervention. Data was analyzed using descriptive statistics, one-way ANOVA and Paired t-test. Results: The results showed a significant difference between fatigue scores in intervention and control groups before and after the intervention (P<0.001). After the foot reflexology, the fatigue score in intervention group reduced to 3.8±1.27 (vs. 4.34±1.35 before the intervention), while the fatigue score in control group increased to 5.19±0.87 (vs. 4.91±1.04 before the intervention) (P<0.05). The placebo group showed no significant difference before and after the intervention (P=0.9). Conclusion: Reflexology can be used as a nursing intervention in reducing fatigue among patients undergoing hemodialysis. © 2016, Mazandaran University of Medical Sciences. All rights reserved

    Quality of life with conservative care compared with assisted peritoneal dialysis and haemodialysis

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    Background. There is little information about quality of life (QoL) for patients with end-stage kidney disease (ESKD) choosing conservative kidney management (CKM). The Frail and Elderly Patients on Dialysis (FEPOD) study demonstrated that frailty was associated with poorer QoL outcomes with little difference between dialysis modalities [assisted peritoneal dialysis (aPD) or haemodialysis (HD)]. We therefore extended the FEPOD study to include CKM patients with estimated glomerular filtration rate ⌉10 mL/min/1.73m2 (i.e. individuals with ESKD otherwise likely to be managed with dialysis). Methods. CKM patients were propensity matched to HD and aPD patients by age, gender, ethnicity, diabetes status and index of deprivation. QoL outcomes measured were Short Form-12 (SF12), Hospital Anxiety and Depression Scale depression score, symptom score, Illness Intrusiveness Rating Scale (IIRS) and Renal Treatment Satisfaction Questionnaire. Frailty was assessed using the Clinical Frailty Scale. Generalized linear modelling was used to assess the impact of treatment modality on QoL outcomes, adjusting for baseline characteristics. Results. In total, 84 (28 CKM, 28 HD and 28 PD) patients were included. Median age for the cohort was 82 (79-88) years. Compared with CKM, aPD was associated with higher SF12 physical component score (PCS) [Exp B (95% confidence interval)=1.20 (1.00-1.45), P<0.05] and lower symptom score [Exp B=0.62 (0.43-0.90), P=0.01]; depression score was lower in HD compared with CKM [Exp B=0.70 (0.52-0.92), P=0.01]. Worsening frailty was associated with higher depression scores [Exp B=2.59 (1.45-4.62), P<0.01], IIRS [Exp B=1.20 (1.12-1.28), P<0.01] and lower SF12 PCS [Exp B=0.87 (0.83-0.93), P<0.01]. Conclusion. Treatment by dialysis, both with aPD and HD, improved some QoL measures. Overall, aPD was equal to or slightly better than the other modalities in this elderly population. However, as in the primary FEPOD study, frailty was associated with worse QoL measures irrespective of CKD modality. These findings highlight the need for an individualized approach to the management of ESKD in older people.Peer reviewedFinal Published versio

    Coenzyme Q10 dose-escalation study in hemodialysis patients: safety, tolerability, and effect on oxidative stress.

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    BackgroundCoenzyme Q10 (CoQ10) supplementation improves mitochondrial coupling of respiration to oxidative phosphorylation, decreases superoxide production in endothelial cells, and may improve functional cardiac capacity in patients with congestive heart failure. There are no studies evaluating the safety, tolerability and efficacy of varying doses of CoQ10 in chronic hemodialysis patients, a population subject to increased oxidative stress.MethodsWe performed a dose escalation study to test the hypothesis that CoQ10 therapy is safe, well-tolerated, and improves biomarkers of oxidative stress in patients receiving hemodialysis therapy. Plasma concentrations of F2-isoprostanes and isofurans were measured to assess systemic oxidative stress and plasma CoQ10 concentrations were measured to determine dose, concentration and response relationships.ResultsFifteen of the 20 subjects completed the entire dose escalation sequence. Mean CoQ10 levels increased in a linear fashion from 704 ± 286 ng/mL at baseline to 4033 ± 1637 ng/mL, and plasma isofuran concentrations decreased from 141 ± 67.5 pg/mL at baseline to 72.2 ± 37.5 pg/mL at the completion of the study (P = 0.003 vs. baseline and P &lt; 0.001 for the effect of dose escalation on isofurans). Plasma F2-isoprostane concentrations did not change during the study.ConclusionsCoQ10 supplementation at doses as high as 1800 mg per day was safe in all subjects and well-tolerated in most. Short-term daily CoQ10 supplementation decreased plasma isofuran concentrations in a dose dependent manner. CoQ10 supplementation may improve mitochondrial function and decrease oxidative stress in patients receiving hemodialysis.Trial registrationThis clinical trial was registered on clinicaltrials.gov [NCT00908297] on May 21, 2009

    Genetic prescreening of a candidate for laser refractive surgery identifies risk for inadequate tissue response: a case report

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    BACKGROUND: Inadequate response to corneal laser refractive surgery, e.g., ectatic corneal diseases, may not be identified by conventional examinations, hence creating therapeutic uncertainty. Herein we demonstrate the application of genetic prescreening to augment preassessment for corneal laser refractive surgery and highlight the ability to prevent the possibility of enrolling a subject at risk for developing ectatic corneal diseases. CASE PRESENTATION: Preoperative tests were performed alongside deoxyribonucleic acid (DNA) sequencing of 75 genes specific to the structure and health of the eye of a 44-year-old Caucasian male candidate for corneal laser refractive surgery. The patient had no medical, family, or psychosocial history, nor symptoms that could lead to suspect any corneal abnormalities, and conventional preoperative tests confirmed that no corneal abnormalities were present. The sequencing results uncovered rare DNA variants within the ADGRV1, PTK2, ZNF469, and KRT15 genes. These variants were considered potential risk factors for inadequate response in the patient post corneal laser refractive surgery. Subsequent reevaluation with three different last-generation corneal tomographers identified in the left eye a “warning” for a deformity of the posterior profile of the cornea. CONCLUSIONS: Genetic prescreening identifies potential risk of inadequate response to corneal laser refractive surgery where current technologies in use may lead to a hazardous predictive diagnostic uncertainty
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