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1.
Sci Rep ; 12(1): 11324, 2022 07 05.
Article in English | MEDLINE | ID: mdl-35790780

ABSTRACT

Phytohormones mediate physiological, morphological, and enzymatic responses and are important regulators of plant growth and development at different stages. Even though temperature is one of the most important abiotic stressors for plant development and production, a spike in the temperature may have disastrous repercussions for crop performance. Physiology and growth of two tomato genotypes ('Ahmar' and 'Roma') were studied in two growth chambers (25 and 45 °C) when gibberellic acid (GA3) was applied exogenously. After the 45 days of planting, tomato plants were sprayed with GA3 at concentrations of 25, 50, 75, and 100 mg L-1, whereas untreated plants were kept as control. Under both temperature conditions, shoot and root biomass was greatest in 'Roma' plants receiving 75 mg L-1 GA3, followed by 50 mg L-1 GA3. Maximum CO2 index, photosynthetic rate, transpiration rate, and greenness index were recorded in 'Roma' plants cultivated at 25 °C, demonstrating good effects of GA3 on tomato physiology. Likewise, GA3 enhanced the proline, nitrogen, phosphorus, and potassium levels in the leaves of both genotypes at both temperatures. Foliar-sprayed GA3 up to 100 mg L-1 alleviated the oxidative stress, as inferred from the lower concentrations of MDA and H2O2, and boosted the activities of superoxide dismutase, peroxidase, catalase. The difference between control and GA3-treated heat-stressed plants suggests that GA3 may have a function in mitigating heat stress. Overall, our findings indicate that 75 mg L-1 of GA3 is the optimal dosage to reduce heat stress in tomatoes and improve their morphological, physiological, and biochemical characteristics.


Subject(s)
Solanum lycopersicum , Gibberellins/pharmacology , Heat-Shock Response , Solanum lycopersicum/genetics , Photosynthesis
2.
Int J Biol Macromol ; 187: 830-839, 2021 Sep 30.
Article in English | MEDLINE | ID: mdl-34331979

ABSTRACT

Silver nanoparticles (AgNPs) have recently emerged as promising growth promoters and immune-lifting agents in the poultry industry. This study investigated the potential impact of AgNP supplementation in the drinking water (DW) of broiler chickens during the fattening period. AgNPs were produced through chemical reduction using starch as a reducing and stabilizing agent. Different concentrations (1-5 ppm) of AgNPs were prepared and added to the DW of five different groups of chickens. Results confirmed efficient and safe application of AgNPs in DW at concentrations up to 2 ppm in term of growth performance (body weight, body weight gain, and feed conversion ratio) and hematological parameters. However, higher concentrations (3-5 ppm) induced dose-dependent mild-to-moderate adverse effects on hematological, biochemical, and oxidative parameters (MDA, TAC, and GSH-px). While growth performance, gene expression of fibroblast growth factor 2 (FGF2), vascular endothelial growth factor A (VEGFA),and insulin-like growth factor (IGF1) in muscle, histopathological and immunohistochemical evaluation of liver, kidney, spleen, bursa, and thymus, and ultrastructural analysis of breast muscle were not significantly affected, even at high concentrations of AgNPs. Therefore, supplementation of AgNPs up to 2 ppm in the DW of broilers is promising.


Subject(s)
Chickens/growth & development , Immune System/drug effects , Metal Nanoparticles , Muscle, Skeletal/drug effects , Silver Compounds/administration & dosage , Starch/administration & dosage , Weight Gain/drug effects , Administration, Oral , Animals , Biomarkers/blood , Chickens/genetics , Chickens/immunology , Chickens/metabolism , Drinking Water , Gene Expression Regulation , Immune System/immunology , Immune System/metabolism , Male , Muscle, Skeletal/growth & development , Muscle, Skeletal/ultrastructure , Organ Size
3.
Toxicol Res (Camb) ; 9(5): 693-705, 2020 Sep.
Article in English | MEDLINE | ID: mdl-33178430

ABSTRACT

In the present study, the protective effects of honey and bee venom (BV) either independently or in combination against lipopolysaccharide (LPS) and carbon tetrachloride (CCl4)-induced hepatoxicity, lipid peroxidation, and hematological alterations in male albino rats were investigated. In addition, histopathological alterations of hepatic tissues induced by LPS/CCL4 were recorded. Sixty-four of male albino rats of average weight 120-150 g were included in this study. Rats were divided into eight equal groups of eight. The obtained results demonstrated that treatment with LPS/CCl4 caused an increase in the levels of alpha-fetoprotein, which was accompanied by changes in the hepatic function biomarkers that characterized by the increased levels of transaminases (AST, ALT). The results showed oxidative stress as assigned by the increase in lipid peroxide. Meantime detraction in the antioxidants, including glutathione peroxidase was observed. Interruptions in biochemical parameters accompanied by disturbances in hematological parameters and liver histopathology were resulted due to exposure to LPS/CCl4. This study showed the use of honey and BV provided a protective effect on hepatotoxicity induced by LPS/CCl4. This might have been occurred through the reduction of hepatic transaminases and the "Alpha-fetoprotein" in serum and the equilibration of the antioxidation system, thereby, inhibiting the reactive oxygen species accumulation. Honey and BV administration reestablish disturbed hematological parameters and liver histopathology persuaded by LPS/CCl4. More interesting, we demonstrated that using a combination of the honey and BV showed promising enhancement in their protective effects over the use of just one of the two reagents.

4.
J Food Biochem ; : e13398, 2020 Aug 04.
Article in English | MEDLINE | ID: mdl-32754950

ABSTRACT

Potential of Casimiroa edulis and Glycosmis pentaphylla leaves extracts were investigated against the effect of two different particle sizes of silver nanoparticles induced toxicity in mice. Mice received silver nanoparticles (AgNPs) (100 mg/kg) with 20 and 100 nm for four weeks followed by daily oral dose of extracts (500 mg/kg) for three weeks. C. edulis leaves identified fourteen phenolic compounds while, G. pentaphylla leaves identified, twelve phenolic compounds. Additionally, biochemical, genotoxicity, mutagenicity, and histopathological investigations were carried out, revealed that liver function activities, lipid profile, hydrogen peroxide, and C-reactive protein were significantly elevate post AgNPs exposure. While, superoxide dismutase, glutathione-S-transferases, and glutathione peroxidase significantly reduce. A marked amelioration in all detected biomarkers, improved histopathological changes and repair DNA damage after treated with C. edulis and G. pentaphylla leaves extracts. These extracts are used for the first time as promising candidate therapeutic agents against toxicity induced by AgNPs. PRACTICAL APPLICATIONS: The potential applications of AgNPs make it necessary to investigate the possible toxicity associated with release of free silver ions in the biological system. AgNPs of varying particle sizes had toxic effects as evidenced by alterations in some cellular biochemical parameters, genotoxicity, mutagenicity, and histopathological indices on mice. Casimiroa edulis and Glycosmis pentaphylla leaves extracts are used for the first time as promising candidate therapeutic, where they are able to ameliorate the toxicity induced via AgNPs and record vacillate percentage of improvement in the selected biomarkers, as a result of the bioactive secondary metabolites especially flavonoids and other polyphenolic compounds.

5.
J Neurol ; 267(5): 1233-1244, 2020 May.
Article in English | MEDLINE | ID: mdl-30694379

ABSTRACT

Immune-mediated myelopathies are a heterogeneous group of inflammatory spinal cord disorders including autoimmune disorders with known antibodies, e.g. aquaporin-4 IgG channelopathy or anti-myelin oligodendrocyte glycoprotein-associated myelitis, myelopathies in the context of multiple sclerosis and systemic autoimmune disorders with myelopathy, as well as post-infectious and paraneoplastic myelopathies. Although magnetic resonance imaging of the spinal cord is still challenging due to the small dimension of the cord cross-section and frequent movement and susceptibility artifacts, recent methodological advances have led to improved diagnostic evaluation and characterization of immune-mediated myelopathies. Topography, length and width of the lesion, gadolinium enhancement pattern, and changes in morphology over time help in narrowing the broad differential diagnosis. In this review, we give an overview of recent advances in magnetic resonance imaging of immune-mediated myelopathies and its role in the differential diagnosis and monitoring of this heterogeneous group of disorders.


Subject(s)
Autoimmune Diseases of the Nervous System/diagnostic imaging , Magnetic Resonance Imaging , Neuroimaging , Spinal Cord Diseases/diagnostic imaging , Humans , Magnetic Resonance Imaging/standards , Neuroimaging/standards
6.
Waste Manag Res ; 37(12): 1229-1239, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31659932

ABSTRACT

Landfill mining is a prospective tool for the recycling of valuable materials (waste-to-material) and secondary fuel (waste-to-energy) from old, therefore more or less stabilised municipal solid waste landfills. The main target of Horizon 2020 'SMARTGROUND' R&D was improving the availability and accessibility of data and information from both urban landfills and mining dumps through a set of activities to integrate all the data - from existing sources and new information retrieved with time progress - in a single EU database. Concerning urban landfills, a new sampling protocol was designed on the basis of the current Hungarian national municipal solid waste analysis standards, optimised for landfill mining. This protocol was then applied in a sampling campaign on a municipal solid waste landfill in Debrecen, Hungary. The composition and parameters of the landfilled materials were measured as a 12-year timescale. The total wet and dry mass of the valuable components possible for utilisation was estimated.


Subject(s)
Refuse Disposal , Solid Waste , Mining , Prospective Studies , Recycling , Waste Disposal Facilities
7.
Biomarkers ; 24(5): 492-498, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31099265

ABSTRACT

Objective: The aim of the present work is to evaluate the toxicity of titanium dioxide nanoparticles (TiO2NPs) according to their doses and particle sizes. Materials and methods: The effect of five days oral administration of TiO2NPs (21 and 80 nm) with different doses (50, 250 and 500 mg/kg body weight) was assessed in mice via measurement of oxidative stress markers; glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and nitric oxide (NO), liver function indices; aspartate and alanine aminotransferases (AST and ALT), chromosomal aberrations and liver histopathological pattern. Results: The results revealed drastic alterations in all the measured parameters and showed positive correlation with the gradual dose increment. In addition, the smaller particle size of TiO2NPS (21 nm) had more adverse effect in all the selected biochemical parameters, genetic aberrations and histological investigations. Conclusions: Toxicity of TiO2NPs increases in a dose-dependent manner and vice versa with particles size. The evaluated biomarkers are good indicators for TiO2NPs toxicity. More detailed studies are required before the recommendation of TiO2NPS as food additives.


Subject(s)
Biomarkers/blood , Nanoparticles/toxicity , Titanium/toxicity , Alanine Transaminase/blood , Animals , Aspartate Aminotransferases/blood , Catalase/blood , Chromosome Aberrations/drug effects , Dose-Response Relationship, Drug , Glutathione/blood , Liver/metabolism , Liver/pathology , Malondialdehyde/blood , Mice , Nanoparticles/metabolism , Nitric Oxide/metabolism , Oxidative Stress/drug effects , Particle Size , Superoxide Dismutase/blood , Titanium/metabolism
8.
Phys Rev Lett ; 121(21): 211601, 2018 Nov 23.
Article in English | MEDLINE | ID: mdl-30517805

ABSTRACT

The Becchi-Rouet-Stora-Tyutin (BRST) transformations and equations of motion of a gravity-two-form-dilaton system are derived from the product of two Yang-Mills theories in a BRST covariant form, to linear approximation. The inclusion of ghost fields facilitates the separation of the graviton and dilaton. The gravitational gauge fixing term is uniquely determined by those of the Yang-Mills factors which can be freely chosen. Moreover, the resulting gravity-two-form-dilaton Lagrangian is anti-BRST invariant and the BRST and anti-BRST charges anticommute as a direct consequence of the formalism.

9.
Sci Rep ; 8(1): 15191, 2018 10 12.
Article in English | MEDLINE | ID: mdl-30315218

ABSTRACT

Bio-food materials are heterogeneous in structure with cellular diversity, where the majority of the water is located in the intracellular spaces. Understanding of the nature of the microscopic behaviour of water transport is crucial to enhance the energy efficiency in food processing and obtain the better quality of processed food. In this research, apoplastic and symplastic transport of cellular water in the bio-food material during drying was investigated using 1H-NMR-T2 relaxometry. We found that intracellular water (ICW) migrates from intracellular spaces to the intercellular spaces by progressive rupturing the cell membranes while drying at a higher temperatures (60 °C-70 °C). In this case, apoplastic process dominates the transport process. However, at lower temperature (45 °C), cell membranes do not rupture and therefore ICW migrates from cell to the neighbouring cell through micro-capillaries, where the symplastic process dominates the mass transfer at different stages of drying.


Subject(s)
Cell Physiological Phenomena , Dehydration/metabolism , Food , Nutritional Physiological Phenomena , Water/metabolism , Animals , Biological Transport , Food Handling , Fruit/cytology , Fruit/metabolism , Intracellular Space , Spectrum Analysis
10.
Rev Neurol ; 65(9): 385-395, 2017 Nov 01.
Article in Spanish, English | MEDLINE | ID: mdl-29071697

ABSTRACT

INTRODUCTION: Motor imagery is a mental representation of movement without any body movement and its training accelerates motor learning and improves motor skills. A thorough understanding of how to manipulate mental images is necessary before using motor imagery in physical rehabilitation. This systematic review analyzes the psychometric properties of the outcome measures on motor imagery ability for the Spanish-speaking people and discusses its usefulness in people with motor disabilities. MATERIALS AND METHODS: A review was conducted, using the COSMIN checklist to appraise 19 articles on measurement properties of motor imagery ability assessments found in reviewed databases. The criteria for grading the usefulness of instruments to measure motor imagery was established depending on the sensory modality assessed. We found 17 questionnaires. RESULTS: Methodological quality was mostly fair in reliability and validity. Four tests have been considered highly useful in assessing motor imagery. MIQ (alpha = 0.90; EFA=2) and MIQ-R (alpha = 0.84; EFA=2) are the best suited to evaluate motor imagery in Spanish-speaking population. To handle spatial images, MASMI (alpha = 0.93) or MARMI (alpha = 0.90) tests may be more beneficial. CONCLUSIONS: MIQ and MIQ-R evaluate visual and kinesthetic imagery, but these are difficult to use in the physical rehabilitation of people with motor disabilities. Currently, there are no valid Spanish translations of studies regarding motor imagery outcome measures for people with disabilities.


TITLE: Revision sistematica sobre instrumentos de valoracion de la imaginacion motora para poblacion hispanohablante: su uso en rehabilitacion.Introduccion. La imaginacion motora es el acto de imaginar una accion sin realizar el movimiento fisico. Su practica acelera el aprendizaje y mejora las destrezas motrices. Previamente a la rehabilitacion fisica utilizando la imaginacion motora, es necesario evaluar la capacidad de los individuos para formar y manipular imagenes mentales. Esta revision sistematica analiza las propiedades psicometricas de las herramientas existentes que miden la imaginacion motora en la comunidad hispanohablante y discute su utilidad clinica en personas con discapacidad motora. Materiales y metodos. Se hallaron 19 articulos en diferentes bases de datos, y se aplico la escala COSMIN para evaluar los 17 instrumentos de medida hallados sobre imaginacion mental. El criterio utilizado para graduar la utilidad clinica de estas herramientas fue establecido en funcion de la modalidad sensorial evaluada. Resultados. La calidad metodologica de los estudios fue aceptable en terminos de fiabilidad y validez. Cuatro cuestionarios se consideraron de utilidad alta en imaginacion motora. El Movement Imagery Questionnaire (MIQ) (alfa = 0,90; AFE = 2) y su version revisada (MIQ-R) (alfa = 0,84; AFE=2) son los cuestionarios autoadministrables que mejor se ajustan para evaluar la imaginacion motora en la poblacion hispanohablante. Entre los tests espaciales es posible utilizar la medida de la aptitud para formar imagenes mentales espaciales (alfa = 0,93) o la medida de la aptitud para rotar imagenes mentales (alfa = 0,90). Conclusiones. Aunque el MIQ y el MIQ-R evaluan la imaginacion visual y cinestesica, su aplicacion en la rehabilitacion con personas con discapacidad motora es complicada. Actualmente no hay instrumentos validados en castellano para poblacion con discapacidad fisica.


Subject(s)
Imagery, Psychotherapy , Neurological Rehabilitation/methods , Diagnostic Self Evaluation , Humans , Movement , Spain , Treatment Outcome
11.
Metab Brain Dis ; 32(5): 1519-1527, 2017 10.
Article in English | MEDLINE | ID: mdl-28560538

ABSTRACT

Diabetic encephalopathy is an important complication of diabetes characterized by cognitive impairment, neurochemical and structural abnormalities. This study aimed to investigate the effect of coenzyme Q10 (CoQ10) and niacin as well as their combination in the treatment of encephalopathy associated with streptozotocin (STZ)- induced diabetes in rats. Glibenclamide (reference diabetic drug) and donepezil hydrochloride (acetylcholinesterase inhibitor) were also evaluated. Diabetes was induced by a single intraperitoneal injection of STZ (60 mg/kg). One month after STZ injection, diabetic rats were treated with the aforementioned drugs for two weeks. The evaluation was done through measuring glucose level, total antioxidant capacity (TAC), interleukin 6 (IL6), DNA degradation as well as serotonin and noradrenaline as neurotransmitters. The present data illustrated that combining CoQ10 and niacin exhibiting the most potent effect in improving the measured parameters and ameliorating some of diabetes complications.


Subject(s)
Antioxidants/therapeutic use , Brain Diseases/chemically induced , Brain Diseases/prevention & control , Diabetes Mellitus, Experimental/drug therapy , Niacin/therapeutic use , Ubiquinone/analogs & derivatives , Vitamins/therapeutic use , Animals , Antioxidants/metabolism , Blood Glucose/metabolism , Cholinesterase Inhibitors/therapeutic use , Diabetes Mellitus, Experimental/pathology , Donepezil , Glyburide/therapeutic use , Hypoglycemic Agents/therapeutic use , Indans/therapeutic use , Interleukin-6/metabolism , Male , Neurotransmitter Agents/metabolism , Piperidines/therapeutic use , Rats , Rats, Wistar , Ubiquinone/therapeutic use
13.
Mol Neurobiol ; 54(3): 1601-1611, 2017 04.
Article in English | MEDLINE | ID: mdl-26867655

ABSTRACT

Diabetes mellitus (DM) is characterized by hyperglycemia due to insulin inactivity or insufficiency with increasing risk of developing specific complications, including retinopathy, nephropathy, neuropathy, and atherosclerosis. The aim of the present study is to evaluate the efficacy of coenzyme Q10 (CoQ10), niacin, as well as their combination in ameliorating brain disorders associated with streptozotocin (STZ)-induced diabetes in rats. Glibenclamide, a reference diabetic drug, and donepezil, an acetylcholine inhibitor drug, were also evaluated. Diabetes was induced by single intraperitoneal injection of STZ (60 mg/kg body weight (b.wt)). One-month diabetic rats were treated with the selected drugs daily for another two consecutive weeks. The evaluation was done through the estimation of the levels of blood glucose, serum insulin, and oxidative stress markers: malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH); neurotransmitters: acetylcholinesterase (AchE) and dopamine (DA); vasoconstrictor indices: intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1(VCAM-1), and angiotensin II (Ang II); and apoptosis markers: tumor necrosis factor-α (TNF-α) and caspase-3 as well as the histopathological picture of the cerebellum region of the brain. The results revealed that the combination of niacin and CoQ10 improved most of the measured parameters with variable degrees. In conclusion, niacin and CoQ10 are promising dietary supplements in the management of diabetic encephalopathy.


Subject(s)
Brain Diseases/drug therapy , Diabetes Mellitus, Experimental/drug therapy , Niacin/administration & dosage , Ubiquinone/analogs & derivatives , Animals , Blood Glucose/drug effects , Blood Glucose/metabolism , Brain Diseases/blood , Brain Diseases/pathology , Diabetes Mellitus, Experimental/blood , Diabetes Mellitus, Experimental/pathology , Drug Therapy, Combination , Intercellular Adhesion Molecule-1/blood , Male , Rats , Rats, Wistar , Ubiquinone/administration & dosage , Vascular Cell Adhesion Molecule-1/blood , Vitamin B Complex/administration & dosage
14.
Article in English | MEDLINE | ID: mdl-26565247

ABSTRACT

Within a high-magnetic-field approximation, employing Ruelle's algebraic perturbation theory, a field-dependent free-energy expression is proposed which allows one to determine the magnetic properties of ferrofluids modeled as dipolar hard-sphere systems. We compare the ensuing magnetization curves, following from this free energy, with those obtained by Ivanov and Kuznetsova [Phys. Rev. E 64, 041405 (2001)] as well as with new corresponding Monte Carlo simulation data. Based on the power-series expansion of the magnetization, a closed expression for the magnetization is also proposed, which is a high-density extension of the corresponding equation of Ivanov and Kuznetsova. From both magnetization equations the zero-field susceptibility expression due to Tani et al. [Mol. Phys. 48, 863 (1983)] can be obtained, which is in good agreement with our MC simulation results. From the closed expression for the magnetization the second-order nonlinear magnetic susceptibility is also derived, which shows fair agreement with the corresponding MC simulation data.

15.
Infect Dis (Auckl) ; 8: 5-16, 2015.
Article in English | MEDLINE | ID: mdl-26124666

ABSTRACT

In this paper, we investigate the role of two active constituents isolated from the leaves of Egyptian medicinal plants. D-mannitol a naturally occurring sugar isolated from the leaves Ixora undulata Roxb., and the pectin a linear chain homogalacturonan (HG) polysaccharide isolated from the leaves of Linum grandiflorum Desf. (scarlet flax). Both are evaluated for their therapeutic effect against schistosomiasis with biochemical and histochemical evaluations and compared with praziquantel, a reference drug. Biochemical studies of hepatic glucose, the glycogen content, and total serum protein were carried out, and histochemical evaluations through serum protein fractions separated by polyacrylamide gel electrophoresis with different molecular weights (260-10 kDa) were made in all groups, in addition to liver and body weight. D-mannitol and pectin show a remarkable effect in enhancing liver and kidney functions through enhancing most protein fractions in the serum of mice infected with Schistosoma mansoni. Also, the glucose and glycogen content in injured liver tissues improved, in addition liver and body weight in the infected groups. Thus they may be of therapeutic potential in the treatment hepatoxicity and nephrotoxicity.

16.
Phys Rev Lett ; 113(23): 231606, 2014 Dec 05.
Article in English | MEDLINE | ID: mdl-25526117

ABSTRACT

By regarding gravity as the convolution of left and right Yang-Mills theories together with a spectator scalar field in the biadjoint representation, we derive in linearized approximation, the gravitational symmetries of general covariance, p-form gauge invariance, local Lorentz invariance, and local supersymmetry from the flat space Yang-Mills symmetries of local gauge invariance and global super-Poincaré symmetry. As a concrete example, we focus on the new minimal (12+12) off shell version of simple four-dimensional supergravity obtained by tensoring the off shell Yang-Mills multiplets (4+4, N_{L}=1) and (3+0, N_{R}=0).

17.
Phys Rev Lett ; 112(13): 131601, 2014 Apr 04.
Article in English | MEDLINE | ID: mdl-24745403

ABSTRACT

We give a unified description of D=3 super-Yang-Mills theory with N=1, 2, 4, and 8 supersymmeties in terms of the four division algebras: reals (R), complexes (C), quaternions (H) and octonions (O). Tensoring left and right super-Yang-Mills multiplets with N=1, 2, 4, 8 we obtain a magic square RR, CR, CC, HR, HC, HH, OR, OC, OH, OO description of D=3 supergravity with N=2, 3, 4, 5, 6, 8, 9, 10, 12, 16.

18.
Clin Neuroradiol ; 24(4): 355-63, 2014 Dec.
Article in English | MEDLINE | ID: mdl-24218066

ABSTRACT

PURPOSE: The aim of this study was to investigate the possibility of quantitative classification in intervertebral disc degeneration using spin-spin relaxation time (T2) cut-off values with regard to morphological classifications. METHODS: Lumbar magnetic resonance (MR) imaging was performed on 21 subjects (a total of 104 lumbar disks). The T2 relaxation time was measured in the nucleus pulposus using a sagittal multi-echo spin-echo sequence. The morphological classification of disc degeneration was assessed independently by three experienced neuroradiologists according to the Pfirrmann and Schneiderman classifications. Receiver operating characteristic analysis was performed among grades to determine T2 cut-off values in each classification. Intra- and interobserver differences were calculated using kappa statistics. RESULTS: Moderate overall interobserver agreement was found between observers in both the Pfirrmann and Schneiderman classification schemes (kappa 0.46 and 0.51), while intraobserver reliability was substantial to almost perfect. The interobserver reliability was only fair in Pfirrmann grades III and IV (kappa 0.33 and 0.36), but the T2 cut-off values still indicated a significant difference between grades (p<0.05). CONCLUSIONS: Interobserver agreement of MR evaluation in patients with intervertebral disc degeneration was only fair to moderate on the classification of more severe disc degeneration in the Pfirrmann and Schneiderman schemes. Based on our results, quantitative T2 cut-off values seem to be a more reliable method to define the degree of disc degeneration, which may help staging intervertebral disc degeneration (IVDD) even if the interobserver reliability is low.


Subject(s)
Data Interpretation, Statistical , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Intervertebral Disc Degeneration/pathology , Lumbar Vertebrae/pathology , Models, Statistical , Adolescent , Adult , Algorithms , Computer Simulation , Feasibility Studies , Female , Humans , Male , Observer Variation , Reproducibility of Results , Sensitivity and Specificity , Young Adult
20.
J Phys Condens Matter ; 25(46): 465108, 2013 Nov 20.
Article in English | MEDLINE | ID: mdl-24153397

ABSTRACT

The influence of polydispersity on the magnetization of ferrofluids is studied based on a previously published magnetization equation of state (Szalai and Dietrich, 2011 J. Phys.: Condens. Matter 23 326004) and computer simulations. The polydispersity of the particle diameter is described by the gamma distribution function. Canonical ensemble Monte Carlo simulations have been performed in order to test these theoretical results for the initial susceptibility and the magnetization. The results for the magnetic properties of the polydisperse systems turn out to be in quantitative agreement with our present simulation data. In addition, we find good agreement between our theory and experimental data for magnetite-based ferrofluids.

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