Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
Add more filters










Publication year range
1.
J Environ Manage ; 344: 118628, 2023 Oct 15.
Article in English | MEDLINE | ID: mdl-37536237

ABSTRACT

Organic and inorganic soil amendments are used to increase crop yields and fertilizer efficiency, as well as to improve the physical and biological properties of soil, increase carbon sequestration, and restore contaminated and saline soils. The present study aimed to evaluate the effect of various zeolite composites mixed with either lignite or leonardite on the biomass production of spring wheat and rapeseed and their root morphology. A pot experiment involved the application of the following treatments: zeolite-carbon, zeolite-vermiculite composites, both mixed with lignite or leonardite, and a control treatment with no amendments. Inorganic composites were applied in a dose of 3% and 6%. The study also included an analysis of the root morphometric parameters and aboveground biomass of spring wheat and rapeseed. The lowest productivity was observed when both crops were not enriched with fertilizers or other amendments, 24.92 g per pot and 29.83 g per pot for spring wheat and rapeseed, respectively. The application of mineral fertilizers in combination with zeolite-carbon composite gave the highest aboveground biomass of spring wheat, 110.11 g per pot. Both zeolite-carbon and zeolite-vermiculite composites modified the morphological parameters of roots, with the control treatment showing the lowest root length and dry matter. Although mineral fertilization was found to have a positive impact root development in relation to untreated control, the treatment amended with zeolite-carbon composite and leonardite exhibited the highest root length and biomass of spring wheat. No other soil amendments improved the properties of rapeseed roots.


Subject(s)
Brassica napus , Zeolites , Soil , Triticum , Biomass , Fertilizers/analysis , Carbon
2.
Materials (Basel) ; 16(6)2023 Mar 07.
Article in English | MEDLINE | ID: mdl-36984022

ABSTRACT

Waste fly ash, with both low (with the addition of vermiculite) and high contents of unburned coal, were subjected to hydrothermal syntheses aiming to obtain zeolite composite materials-zeolite + vermiculite (NaX-Ver) and zeolite + unburned carbon (NaX-C). The composites were compared with parent zeolite obtained from waste fly ash with a low content of unburned carbon (NaX-FA). In this study, the physicochemical characteristics of the obtained materials were evaluated. The potential application of the investigated zeolites for the adsorption of ammonium ions from aqueous solutions was determined. Composite NaX-Ver and parent zeolite NaX-FA were characterized by comparable adsorption capacities toward ammonium ions of 38.46 and 40.00 mg (NH4+) g-1, respectively. The nearly 2-fold lower adsorption capacity of composite NaX-C (21.05 mg (NH4+) g-1) was probably a result of the lower availability of ion exchange sites within the material. Adsorbents were also regenerated using 1 M NaCl solution at a pH of 10 and subjected to 3 cycles of adsorption-desorption experiments, which proved only a small reduction in adsorption properties. This study follows the current trend of waste utilization (fly ash) and the removal of pollutants from aqueous solutions with respect to their reuse, which remains in line with the goals of the circular economy.

3.
PLoS One ; 12(2): e0172804, 2017.
Article in English | MEDLINE | ID: mdl-28235039

ABSTRACT

BACKGROUND: Accurate measurement of physical performance in individuals with musculoskeletal pain is essential. Accelerometry is a powerful tool for this purpose, yet the current methods designed to evaluate energy expenditure are not optimized for this population. The goal of this study is to empirically derive a method of accelerometry analysis specifically for musculoskeletal pain populations. METHODS: We extracted data from 6,796 participants in the 2003-4 National Health and Nutrition Examination Survey (NHANES) including: 7-day accelerometry, health and pain questionnaires, and anthropomorphics. Custom macros were used for data processing, complex survey regression analyses, model selection, and statistical adjustment. After controlling for a multitude of variables that influence physical activity, we investigated whether distinct accelerometry profiles accompany pain in different locations of the body; and we identified the intensity intervals that best characterized these profiles. RESULTS: Unique accelerometry profiles were observed for pain in different body regions, logically clustering together based on proximity. Based on this, the following novel intervals (counts/minute) were identified and defined: Performance Sedentary (PSE) = 1-100, Performance Light 1 (PL1) = 101-350, Performance Light 2 (PL2) = 351-800, Performance Light 3 (PL3) = 801-2500, and Performance Moderate/Vigorous (PMV) = 2501-30000. The refinement of accelerometry signals into these new intervals, including 3 distinct ranges that fit inside the established light activity range, best captures alterations in real-life physical performance as a result of regional pain. DISCUSSION AND CONCLUSIONS: These new accelerometry intervals provide a model for objective measurement of real-life physical performance in people with pain and musculoskeletal disorders, with many potential uses. They may be used to better evaluate the relationship between pain and daily physical function, monitor musculoskeletal disease progression, gauge disease severity, inform exercise prescription, and quantify the functional impact of treatments. Based on these findings, we recommend that future studies of pain and musculoskeletal disorders analyze accelerometry output based on these new "physical performance" intervals.


Subject(s)
Accelerometry , Exercise , Musculoskeletal Pain/diagnosis , Musculoskeletal Pain/therapy , Pain Management/methods , Pain Measurement/methods , Algorithms , Anthropometry , Cluster Analysis , Databases, Factual , Disabled Persons , Disease Progression , Humans , Models, Statistical , Nutrition Surveys , Regression Analysis , Software , Surveys and Questionnaires , United States
5.
PM R ; 6(10): 882-92, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24631950

ABSTRACT

OBJECTIVES: To develop and implement methodologies for characterizing accelerometry-derived patterns of physical activity (PA) in the United States in relation to demographics, anthropometrics, behaviors, and comorbidities using the National Health and Nutrition Examination Survey (NHANES) dataset. DESIGN: Retrospective analysis of nationally representative database. SETTING: Computer-generated modeling in silico. PARTICIPANTS: A total of 6329 adults in the United States from the NHANES 2003-2004 database. METHODS: To discover subtle multivariate signal in the dynamic and noisy accelerometry data, we developed a novel approach, termed discretized multiple adaptive regression and implemented the algorithm in SAS 9.2 (SAS Institute, Cary, NC). MAIN OUTCOME MEASUREMENTS: Demographic, anthropometric, comorbidity, and behavioral variables. RESULTS: The intensity of PA decreased with both increased age and increased body mass index. Both greater education and greater income correlate with increased activity over short durations and reduced activity intensity over long durations. Numerous predictors demonstrated effects within activity ranges that may be masked by use of the standard activity intensity intervals. These include age, one of the most robust variables, where we discovered decreasing activities inside the moderate activity range. It also includes gender, where women compared with men have increased proportions of active times up to the center of light activity range, and income greater than $45,000, where a complex effect is seen with little correspondence to existing cut-points. CONCLUSIONS: The results presented in this study suggest that the method of multiple regression and heat map visualization can generate insights otherwise hidden in large datasets such as NHANES. A review of the provided heat maps reveals the trends discussed previously involving demographic, anthropometric, comorbidity, and behavioral variables. It also demonstrates the power of accelerometry to expose alterations in PA. Ultimately, this study provides a US population-based norm to use in future studies of PA.


Subject(s)
Accelerometry/methods , Computer Simulation , Motor Activity , Nutrition Surveys/methods , Obesity/epidemiology , Adult , Aged , Female , Humans , Male , Middle Aged , Obesity/prevention & control , Reproducibility of Results , Retrospective Studies , United States/epidemiology , Young Adult
6.
Top Spinal Cord Inj Rehabil ; 18(4): 315-21, 2012.
Article in English | MEDLINE | ID: mdl-23459661

ABSTRACT

The management of chronic respiratory insufficiency and/or long-term inability to breathe independently has traditionally been via positive-pressure ventilation through a mechanical ventilator. Although life-sustaining, it is associated with limitations of function, lack of independence, decreased quality of life, sleep disturbance, and increased risk for infections. In addition, its mechanical and electronic complexity requires full understanding of the possible malfunctions by patients and caregivers. Ventilator-associated pneumonia, tracheal injury, and equipment malfunction account for common complications of prolonged ventilation, and respiratory infections are the most common cause of death in spinal cord-injured patients. The development of functional electric stimulation (FES) as an alternative to mechanical ventilation has been motivated by a goal to improve the quality of life of affected individuals. In this article, we will review the physiology, types, characteristics, risks and benefits, surgical techniques, and complications of the 2 commercially available FES strategies - phrenic nerve pacing (PNP) and diaphragm motor point pacing (DMPP).

7.
Bioorg Med Chem Lett ; 14(15): 4069-74, 2004 Aug 02.
Article in English | MEDLINE | ID: mdl-15225728

ABSTRACT

A recently reported dual LPA(1)/LPA(3) receptor antagonist (1) has been modified so as to modulate the basicity, sterics, and dipole moment of the 2-pyridyl moiety. Additionally, the implications of installing nonhydrolyzable phosphate head group isosteres with regard to antagonist potency and selectivity at LPA receptors is described. This study has resulted in the development of the first nonhydrolyzable and presumably phosphatase-resistant LPA(3)-selective antagonist reported to date.


Subject(s)
Pyridines/pharmacology , Receptors, Lysophosphatidic Acid/antagonists & inhibitors , Animals , Fibroblasts/drug effects , Fibroblasts/physiology , Guanosine 5'-O-(3-Thiotriphosphate)/metabolism , Molecular Conformation , Molecular Structure , Pyridines/chemical synthesis , Pyridines/chemistry , Structure-Activity Relationship
8.
Bioorg Med Chem Lett ; 14(13): 3473-6, 2004 Jul 05.
Article in English | MEDLINE | ID: mdl-15177455

ABSTRACT

Using an N-oleoyl ethanolamide scaffold, a series of phosphate polar head group analogues of LPA comprised of various alpha-substituted phosphonates and thiophosphates was prepared. In a broken cell GTP[gamma35S] binding assay, agonist activity was evaluated at the three LPA receptors of the endothelial differentiation gene (Edg) family. This study has resulted in the discovery of a nonhydrolyzable LPA1-selective agonist (11). Additionally, thiophosphate 19 bears an isosteric phosphate mimetic that confers agonism at the LPA1 receptor but not LPA2.


Subject(s)
Lysophospholipids/chemical synthesis , Phosphates/chemistry , Phosphoric Acids/chemistry , Receptors, Lysophosphatidic Acid/agonists , Amides/chemistry , Animals , Cells, Cultured , Lysophospholipids/pharmacology , Oleic Acids/chemistry , Radioligand Assay/methods , Receptors, Lysophosphatidic Acid/metabolism , Stearic Acids/chemistry
9.
Bioorg Med Chem Lett ; 14(11): 2735-40, 2004 Jun 07.
Article in English | MEDLINE | ID: mdl-15125924

ABSTRACT

A recently reported dual LPA1/LPA3 receptor antagonist (VPC12249, 1) has been modified herein so as to optimize potency and selectivity at LPA receptors. Compounds containing variation in the acyl lipid chain and linker region have been synthesized and screened for activity at individual LPA receptors. LPA1-selective (14b) and LPA3-selective (10g,m) compounds of modest potency have been discovered. Additionally, 2-pyridyl derivative 10t exhibits a Ki value of 18 nM at the LPA1 receptor and is significantly more potent than 1 at the LPA3 receptor. This paper describes the synthetic methods, biological evaluation, and structure-activity relationships (SARs) of LPA receptor antagonists.


Subject(s)
Receptors, Lysophosphatidic Acid/antagonists & inhibitors , Acylation , Cell Line , Cross-Linking Reagents/chemistry , Dose-Response Relationship, Drug , Ethanolamines/chemical synthesis , Ethanolamines/pharmacology , Guanosine 5'-O-(3-Thiotriphosphate)/metabolism , Humans , Inhibitory Concentration 50 , Ligands , Lipids/chemistry , Protein Binding , Receptors, Lysophosphatidic Acid/genetics , Structure-Activity Relationship , Transfection
10.
J Biol Chem ; 278(14): 11962-9, 2003 Apr 04.
Article in English | MEDLINE | ID: mdl-12554733

ABSTRACT

Lysophosphatidic acid (LPA) is a bioactive lysophospholipid mediator that acts through G protein-coupled receptors. Most cell lines in culture express one or more LPA receptors, making it difficult to assign a response to specific LPA receptors. Dissection of the signaling properties of LPA has been hampered by lack of LPA receptor subtype-specific agonists and antagonists. The present study characterizes an ester-linked thiophosphate derivative (1-oleoyl-2-O-methyl-rac-glycerophosphothionate, OMPT) of LPA. OMPT is a functional LPA analogue with potent mitogenic activity in fibroblasts. In contrast to LPA, OMPT does not couple to the pheromone response through the LPA(1) receptor in yeast cells. OMPT induces intracellular calcium increases efficiently in LPA(3) receptor-expressing Sf9 cells but poorly in LPA(2) receptor-expressing cells. Guanosine 5'-O-(3-[(35)S]thio)triphosphate binding assays in mammalian cells showed that LPA exhibits agonistic activity on all three LPA receptor subtypes, whereas OMPT has a potent agonistic effect only on the LPA(3) receptor. In transiently transfected HEK293 cells, OMPT stimulates mitogen-activated protein kinases through the LPA(3) but not the LPA(1) or LPA(2) receptors. Furthermore, OMPT-induced intracellular calcium mobilization in mammalian cells is efficiently inhibited by the LPA(1)/LPA(3) receptor-selective antagonist VPC12249. These results establish that OMPT is an LPA(3)-selective agonist. OMPT binding to the LPA(3) receptor in mammalian cells is sufficient to elicit multiple responses, including activation of G proteins, calcium mobilization, and activation of mitogen-activated protein kinases. Thus OMPT offers a powerful probe for the dissection of LPA signaling events in complex mammalian systems.


Subject(s)
Lysophospholipids/pharmacology , Organothiophosphates/pharmacology , Phosphatidic Acids/pharmacology , Receptors, Cell Surface/agonists , Receptors, G-Protein-Coupled , Signal Transduction/drug effects , 3T3 Cells , Animals , Calcium/metabolism , Humans , Kidney/cytology , Lysophospholipids/chemistry , Mammals , Mice , Mice, Inbred C3H , Mitogens/pharmacology , Receptors, Cell Surface/antagonists & inhibitors , Receptors, Lysophosphatidic Acid , Spodoptera , Yeasts/drug effects
SELECTION OF CITATIONS
SEARCH DETAIL
...