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1.
Opt Express ; 32(9): 15978-15992, 2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38859236

ABSTRACT

This paper presents a laboratory study of the aberrations calculation in underwater turbulence using the Shack-Hartmann wavefront sensor. The wavefront decomposition method and Zernike polynomials determine the aberration parameters. In our experimental setup, the turbulent phase screen generator is located in two locations: near the transmitter and therefore far from the receiver, and near the receiver and consequently far from the transmitter. Additionally, we investigate the impact of aperture diameter on turbulence-induced aberrations in the optical receiver system. However, it is essential to note that the coefficients of Zernike polynomials obtained using this method are subject to errors caused by receiver sensor noise and correlation between the polynomials. To address this, we first calculate the coefficients in different arrangements and then correct measurement errors arising from sensor noise and polynomial coefficient correlation.

2.
Orphanet J Rare Dis ; 19(1): 120, 2024 Mar 13.
Article in English | MEDLINE | ID: mdl-38481240

ABSTRACT

BACKGROUND: Locoregional recurrence is a critical factor in the prognosis of sinonasal malignancies. Due to the rarity of these tumours, as well as the heterogeneity of histologies and anatomical subsites, there is little evidence regarding the rate and location of regional metastases in sinonasal malignancies. Elective regional lymph node dissection in the therapy of sinonasal malignancies has become controversial. On the one hand, elective regional lymph node dissection is considered to be an overtreatment in the cN0 cases. On the other hand, undetected occult lymphatic metastases are associated with a poor prognosis. In this study, we discuss the role of sentinel lymph node biopsy as a minimally invasive procedure in the treatment of sinonasal malignancies based on our two years of practical experience and the currently available data. RESULTS: This is a descriptive, monocentric, retrospective study, including 20 cases of cN0 malignant sinonasal neoplasm, that underwent a surgical therapy between 2020 and 2022. The following aspects were investigated: tumour entity, localisation of the primary tumour, tumoral stage, localisation of the sentinel lymph nodes, and postoperative complications. Squamous cell carcinoma was the most frequently diagnosed tumour entity (50%), followed by adenocarcinoma (20%) and malignant melanoma (15%), adenoid cystic carcinoma and mucoepidermoid carcinoma. Sentinel lymph nodes were most frequently found in the ipsilateral neck region I (45%), followed by the ipsilateral neck region II (40%). In all cases, the removed lymph nodes were free of malignancy. There were no postoperative complications due to lymph node biopsy. There were no recurrences during the study period. CONCLUSION: Sentinel node biopsy could add more safety to the management of cN0 sinonasal malignancies due to its low morbidity. Whether SNB could provide an alternative to elective neck dissection in the management of SNM should be investigated in further studies.


Subject(s)
Sentinel Lymph Node Biopsy , Skin Neoplasms , Humans , Sentinel Lymph Node Biopsy/methods , Retrospective Studies , Neoplasm Recurrence, Local/surgery , Skin Neoplasms/pathology , Lymphatic Metastasis
3.
Int J Biol Macromol ; 253(Pt 7): 127170, 2023 Dec 31.
Article in English | MEDLINE | ID: mdl-37783250

ABSTRACT

The primary objective of this paper is to serve as a comprehensive study on the synthesis of stimulus-sensitive micelles based on polysaccharides. In pursuit of this goal, functionalization with polylactide (PLA) was used as the water-resistance part and poly[2(Dimethyl amino)ethyl methacrylate] (PDMAEMA) or poly(methacrylic acid) (PMA) were employed as the stimulus-sensitive part to create micelles with a simple structure. FTIR and 1HNMR measurements were utilized to characterize the functionalized polysaccharides. Fluorescence spectroscopy was used to determine the critical micelle concentration. The average micelles' diameter, as observed in SEM and TEM pictures, ranges from 50 to 200 nm. To gain a better understanding of the potential of theses micelles for delivering drugs in a stimulus-sensitive manner, drug release tests were conducted. The cytotoxicity of these nano-vehicles was examined using the MTT assay. Utilizing MCF7 cells stained with DAPI and Mito Tracker, cellular uptake studies were also investigated. The results indicate that the behavior of the micelles is nearly same even though they used polysaccharides with various charge densities or different stimulus sensitive polymers. This approach, therefore, demonstrates that a broad range of micelle production is possible by employing diverse polysaccharides functionalized with PLA and polymethacrylates.


Subject(s)
Chitosan , Micelles , Starch , Alginates , Polymers/chemistry , Polyesters/chemistry , Methacrylates/chemistry
4.
Lasers Surg Med ; 53(3): 309-315, 2021 03.
Article in English | MEDLINE | ID: mdl-32573010

ABSTRACT

BACKGROUND AND OBJECTIVES: Hereditary hemorrhagic telangiectasia (HHT) is a hereditary condition that is associated with arteriovenous malformations. A common site for these malformations is the nasal mucosa, which is associated with severe epistaxis and debilitation for affected patients. We evaluated the efficacy and safety of blue light laser technology in treating these endonasal manifestations in a retrospective chart analysis. Additionally, we compared blue light laser technology to bipolar coagulation in an animal model. STUDY DESIGN/MATERIALS AND METHODS: We performed a retrospective chart analysis of all patients that were diagnosed with HHT and received endonasal blue light laser treatment between 10/2017 and 04/2019. In addition, we performed bipolar or blue light laser coagulation of all macroscopically visible vessels on thyroid gland lobes (n = 4) from Dunkin-Hartley Guinea Pigs. Hematoxylin-eosin (HE) staining was then used to visualize depth and area of coagulation surrounding these vessels. RESULTS: One hundred and fifty-one treatments in 23 patients were analyzed. Under regular blue light laser treatment, quality of life (QOL), indicated on a visual analog scale from 1 to 10, gradually increased significantly from 5.6 ± 0.5 (before the first treatment) to 7.5 ± 0.9 (after the second treatment). Following this, QOL remained steady throughout additional treatments. Adverse effects were not recorded. HE staining showed that coagulation depth (162 ± 56 vs. 586 ± 192 µm) and area (74 ± 35 vs. 1015 ± 449 µm2 ) were significantly lower after laser treatment. CONCLUSION: Blue light laser therapy is safe and efficient in treating HHT. Damage to the surrounding tissue is significantly lower compared with bipolar coagulation. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.


Subject(s)
Telangiectasia, Hereditary Hemorrhagic , Animals , Epistaxis , Guinea Pigs , Humans , Quality of Life , Retrospective Studies , Telangiectasia, Hereditary Hemorrhagic/complications , Treatment Outcome
8.
Cardiovasc Res ; 114(2): 312-323, 2018 02 01.
Article in English | MEDLINE | ID: mdl-29036612

ABSTRACT

Aims: CD40 ligand (CD40L) signaling controls vascular oxidative stress and related dysfunction in angiotensin-II-induced arterial hypertension by regulating vascular immune cell recruitment and platelet activation. Here we investigated the role of CD40L in experimental hyperlipidemia. Methods and results: Male wild type and CD40L-/- mice (C57BL/6 background) were subjected to high fat diet for sixteen weeks. Weight, cholesterol, HDL, and LDL levels, endothelial function (isometric tension recording), oxidative stress (NADPH oxidase expression, dihydroethidium fluorescence) and inflammatory parameters (inducible nitric oxide synthase, interleukin-6 expression) were assessed. CD40L expression, weight, leptin and lipids were increased, and endothelial dysfunction, oxidative stress and inflammation were more pronounced in wild type mice on a high fat diet, all of which was almost normalized by CD40L deficiency. Similar results were obtained in diabetic db/db mice with CD40/TRAF6 inhibitor (6877002) therapy. In a small human study higher serum sCD40L levels and an inflammatory phenotype were detected in the blood and Aorta ascendens of obese patients (body mass index > 35) that underwent by-pass surgery. Conclusion: CD40L controls obesity-associated vascular inflammation, oxidative stress and endothelial dysfunction in mice and potentially humans. Thus, CD40L represents a therapeutic target in lipid metabolic disorders which is a leading cause in cardiovascular disease.


Subject(s)
CD40 Ligand/metabolism , Diabetes Mellitus, Type 2/metabolism , Diet, High-Fat , Endothelium, Vascular/metabolism , Inflammation Mediators/metabolism , Inflammation/metabolism , Obesity/metabolism , Oxidative Stress , Vasodilation , Animals , Anti-Inflammatory Agents/pharmacology , Antioxidants/pharmacology , Biomarkers/metabolism , CD40 Ligand/antagonists & inhibitors , CD40 Ligand/deficiency , CD40 Ligand/genetics , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/physiopathology , Diabetes Mellitus, Type 2/prevention & control , Disease Models, Animal , Endothelium, Vascular/drug effects , Endothelium, Vascular/physiopathology , Humans , Hyperlipidemias/genetics , Hyperlipidemias/metabolism , Hyperlipidemias/physiopathology , Inflammation/genetics , Inflammation/physiopathology , Inflammation/prevention & control , Interleukin-6/metabolism , Lipids/blood , Male , Mice, Inbred C57BL , Mice, Knockout , Myocardium/metabolism , NADPH Oxidases/metabolism , Nitric Oxide Synthase Type II/metabolism , Obesity/genetics , Obesity/physiopathology , Obesity/prevention & control , Oxidative Stress/drug effects , Platelet Activation , TNF Receptor-Associated Factor 6/antagonists & inhibitors , TNF Receptor-Associated Factor 6/metabolism , Vasodilation/drug effects , Weight Gain
9.
Oxid Med Cell Longev ; 2018: 7845629, 2018.
Article in English | MEDLINE | ID: mdl-30687454

ABSTRACT

OBJECTIVE: Organic nitrates such as isosorbide-5-mononitrate (ISMN) and isosorbide dinitrate (ISDN) are used for the treatment of patients with chronic symptomatic stable coronary artery disease and chronic congestive heart failure. Limiting side effects of these nitrovasodilators include nitrate tolerance and/or endothelial dysfunction mediated by oxidative stress. Here, we tested the therapeutic effects of the dual endothelin (ET) receptor antagonist macitentan in ISMN- and ISDN-treated animals. METHODS AND RESULTS: Organic nitrates (ISMN, ISDN, and nitroglycerin (GTN)) augmented the oxidative burst and interleukin-6 release in cultured macrophages, whereas macitentan decreased the oxidative burst in isolated human leukocytes. Male C57BL/6j mice were treated with ISMN (75 mg/kg/d) or ISDN (25 mg/kg/d) via s.c. infusion for 7 days and some mice in addition with 30 mg/kg/d of macitentan (gavage, once daily). ISMN and ISDN in vivo therapy caused endothelial dysfunction but no nitrate (or cross-)tolerance to the organic nitrates, respectively. ISMN/ISDN increased blood nitrosative stress, vascular/cardiac oxidative stress via NOX-2 (fluorescence and chemiluminescence methods), ET1 expression, ET receptor signaling, and markers of inflammation (protein and mRNA level). ET receptor signaling blockade by macitentan normalized endothelial function, vascular/cardiac oxidative stress, and inflammatory phenotype in both nitrate therapy groups. CONCLUSION: ISMN/ISDN treatment caused activation of the NOX-2/ET receptor signaling axis leading to increased vascular oxidative stress and inflammation as well as endothelial dysfunction. Our study demonstrates for the first time that blockade of ET receptor signaling by the dual endothelin receptor blocker macitentan improves adverse side effects of the organic nitrates ISMN and ISDN.


Subject(s)
Endothelium, Vascular/drug effects , Inflammation/prevention & control , Isosorbide Dinitrate/analogs & derivatives , Isosorbide Dinitrate/toxicity , Oxidative Stress/drug effects , Pyrimidines/pharmacology , Sulfonamides/pharmacology , Vascular Diseases/prevention & control , Animals , Cells, Cultured , Endothelin Receptor Antagonists/pharmacology , Endothelium, Vascular/pathology , Humans , Inflammation/chemically induced , Inflammation/pathology , Male , Mice , Mice, Inbred C57BL , Rats , Rats, Wistar , Vascular Diseases/chemically induced , Vascular Diseases/pathology , Vasodilator Agents/toxicity
10.
J Opt Soc Am A Opt Image Sci Vis ; 34(12): 2126-2137, 2017 Dec 01.
Article in English | MEDLINE | ID: mdl-29240086

ABSTRACT

In this paper, the performance of underwater wireless optical communication (UWOC) links, which is made up of the partially coherent flat-topped (PCFT) array laser beam, has been investigated in detail. Providing high power, array laser beams are employed to increase the range of UWOC links. For characterization of the effects of oceanic turbulence on the propagation behavior of the considered beam, using the extended Huygens-Fresnel principle, an analytical expression for cross-spectral density matrix elements and a semi-analytical one for fourth-order statistical moment have been derived. Then, based on these expressions, the on-axis scintillation index of the mentioned beam propagating through weak oceanic turbulence has been calculated. Furthermore, in order to quantify the performance of the UWOC link, the average bit error rate (BER) has also been evaluated. The effects of some source factors and turbulent ocean parameters on the propagation behavior of the scintillation index and the BER have been studied in detail. The results of this investigation indicate that in comparison with the Gaussian array beam, when the source size of beamlets is larger than the first Fresnel zone, the PCFT array laser beam with the higher flatness order is found to have a lower scintillation index and hence lower BER. Specifically, in the sense of scintillation index reduction, using the PCFT array laser beams has a considerable benefit in comparison with the single PCFT or Gaussian laser beams and also Gaussian array beams. All the simulation results of this paper have been shown by graphs and they have been analyzed in detail.

11.
Int J Mol Sci ; 18(10)2017 Oct 18.
Article in English | MEDLINE | ID: mdl-29057830

ABSTRACT

Sepsis is a severe and multifactorial disease with a high mortality rate. It represents a strong inflammatory response to an infection and is associated with vascular inflammation and oxidative/nitrosative stress. Here, we studied the underlying time responses in the widely used lipopolysaccharide (LPS)-induced endotoxaemia model in mice and rats. LPS (10 mg/kg; from Salmonella Typhosa) was intraperitoneally injected into mice and rats. Animals of every species were divided into five groups and sacrificed at specific points in time (0, 3, 6, 9, 12 h). White blood cells (WBC) decreased significantly in both species after 3 h and partially recovered with time, whereas platelet decrease did not recover. Oxidative burst and iNOS-derived nitrosyl-iron hemoglobin (HbNO) increased with time (maxima at 9 or 12 h). Immune cell infiltration (CD68 and F4/80 content) showed an increase with time, which was supported by increased vascular mRNA expression of VCAM-1, P-selectin, IL-6 and TNF-α. We characterized the time responses of vascular inflammation and oxidative/nitrosative stress in LPS-induced endotoxaemic mice and rats. The results of this study will help to interpret and compare data from different animal species in LPS-induced endotoxaemia models for the identification of new drug targets.


Subject(s)
Bacteremia/metabolism , Oxidative Stress , Salmonella Infections/metabolism , Animals , Bacteremia/blood , Hemoglobins/metabolism , Interleukin-6/metabolism , Leukocyte Count , Lipopolysaccharides/toxicity , Male , Mice , Mice, Inbred C57BL , Nitric Oxide Synthase Type II/metabolism , P-Selectin/metabolism , Platelet Count , Rats , Rats, Wistar , Reaction Time , Salmonella Infections/blood , Species Specificity , Tumor Necrosis Factor-alpha/metabolism , Vascular Cell Adhesion Molecule-1/metabolism
12.
Redox Biol ; 13: 370-385, 2017 10.
Article in English | MEDLINE | ID: mdl-28667906

ABSTRACT

Hyperglycemia associated with inflammation and oxidative stress is a major cause of vascular dysfunction and cardiovascular disease in diabetes. Recent data reports that a selective sodium-glucose co-transporter 2 inhibitor (SGLT2i), empagliflozin (Jardiance®), ameliorates glucotoxicity via excretion of excess glucose in urine (glucosuria) and significantly improves cardiovascular mortality in type 2 diabetes mellitus (T2DM). The overarching hypothesis is that hyperglycemia and glucotoxicity are upstream of all other complications seen in diabetes. The aim of this study was to investigate effects of empagliflozin on glucotoxicity, ß-cell function, inflammation, oxidative stress and endothelial dysfunction in Zucker diabetic fatty (ZDF) rats. Male ZDF rats were used as a model of T2DM (35 diabetic ZDF-Leprfa/fa and 16 ZDF-Lepr+/+ controls). Empagliflozin (10 and 30mg/kg/d) was administered via drinking water for 6 weeks. Treatment with empagliflozin restored glycemic control. Empagliflozin improved endothelial function (thoracic aorta) and reduced oxidative stress in the aorta and in blood of diabetic rats. Inflammation and glucotoxicity (AGE/RAGE signaling) were epigenetically prevented by SGLT2i treatment (ChIP). Linear regression analysis revealed a significant inverse correlation of endothelial function with HbA1c, whereas leukocyte-dependent oxidative burst and C-reactive protein (CRP) were positively correlated with HbA1c. Viability of hyperglycemic endothelial cells was pleiotropically improved by SGLT2i. Empagliflozin reduces glucotoxicity and thereby prevents the development of endothelial dysfunction, reduces oxidative stress and exhibits anti-inflammatory effects in ZDF rats, despite persisting hyperlipidemia and hyperinsulinemia. Our preclinical observations provide insights into the mechanisms by which empagliflozin reduces cardiovascular mortality in humans (EMPA-REG trial).


Subject(s)
Benzhydryl Compounds/therapeutic use , Diabetic Cardiomyopathies/drug therapy , Glucosides/therapeutic use , Hypoglycemic Agents/therapeutic use , Sodium-Glucose Transporter 2 Inhibitors , Animals , Aorta, Thoracic/drug effects , Aorta, Thoracic/metabolism , Benzhydryl Compounds/pharmacology , C-Reactive Protein/metabolism , Endothelium, Vascular/drug effects , Endothelium, Vascular/metabolism , Glucose/metabolism , Glucosides/pharmacology , Glycated Hemoglobin/metabolism , Hypoglycemic Agents/pharmacology , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/metabolism , Male , Oxidative Stress , Rats , Rats, Zucker , Sodium-Glucose Transporter 2/metabolism
13.
Br J Pharmacol ; 174(12): 1620-1632, 2017 06.
Article in English | MEDLINE | ID: mdl-27435156

ABSTRACT

BACKGROUND AND PURPOSE: Excessive inflammation in sepsis causes microvascular thrombosis and thrombocytopenia associated with organ dysfunction and high mortality. The present studies aimed to investigate whether inhibition of dipeptidyl peptidase-4 (DPP-4) and supplementation with glucagon-like peptide-1 (GLP-1) receptor agonists improved endotoxaemia-associated microvascular thrombosis via immunomodulatory effects. EXPERIMENTAL APPROACH: Endotoxaemia was induced in C57BL/6J mice by a single injection of LPS (17.5 mg kg-1 for survival and 10 mg kg-1 for all other studies). For survival studies, treatment was started 6 h after LPS injection. For all other studies, drugs were injected 48 h before LPS treatment. KEY RESULTS: Mice treated with LPS alone showed severe thrombocytopenia, microvascular thrombosis in the pulmonary circulation (fluorescence imaging), increased LDH activity, endothelial dysfunction and increased markers of inflammation in aorta and whole blood (leukocyte-dependent oxidative burst, nitrosyl-iron haemoglobin, a marker of nitrosative stress, and expression of inducible NOS). Treatment with the DPP-4 inhibitor linagliptin or the GLP-1 receptor agonist liraglutide, as well as genetic deletion of DPP-4 (DPP4-/- mice) improved all these parameters. In GLP-1 receptor-deficient mice, both linagliptin and liraglutide lost their beneficial effects and improvement of prognosis. Incubation of platelets and cultured monocytes (containing GLP-1 receptor protein) with GLP-1 receptor agonists inhibited the monocytic oxidative burst and platelet activation, with a GLP-1 receptor-dependent elevation of cAMP levels and PKA activation. CONCLUSIONS AND IMPLICATIONS: GLP-1 receptor activation in platelets by linagliptin and liraglutide strongly attenuated endotoxaemia-induced microvascular thrombosis and mortality by a cAMP/PKA-dependent mechanism, preventing systemic inflammation, vascular dysfunction and end organ damage. LINKED ARTICLES: This article is part of a themed section on Redox Biology and Oxidative Stress in Health and Disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.12/issuetoc.


Subject(s)
Endotoxemia/metabolism , Glucagon-Like Peptide-1 Receptor/metabolism , Microvessels/metabolism , Nitric Oxide/metabolism , Signal Transduction , Venous Thrombosis/metabolism , Animals , Dipeptidyl Peptidase 4/deficiency , Dipeptidyl Peptidase 4/genetics , Dipeptidyl Peptidase 4/metabolism , Endotoxemia/chemically induced , Glucagon-Like Peptide-1 Receptor/agonists , Glucagon-Like Peptide-1 Receptor/deficiency , Lipopolysaccharides/administration & dosage , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Microvessels/drug effects , Oxidative Stress/drug effects , Platelet Activation/drug effects , Signal Transduction/drug effects , Venous Thrombosis/chemically induced
14.
Appl Opt ; 55(23): 6311-20, 2016 Aug 10.
Article in English | MEDLINE | ID: mdl-27534473

ABSTRACT

In this research, based on an analytical expression for cross-spectral density (CSD) matrix elements, coherence and polarization properties of phase-locked partially coherent flat-topped (PCFT) radial array laser beams propagating through weak oceanic turbulence are analyzed. Spectral degrees of coherence and polarization are analytically calculated using CSD matrix elements. Also, the effective width of spatial degree of coherence (EWSDC) is calculated numerically. The simulation is done by considering the effects of source parameters (such as radius of the array setup's circle, effective width of the spectral degree of coherence, and wavelength) and turbulent ocean factors (such as the rate of dissipation of the turbulent kinetic energy per unit mass of fluid and relative strength of temperature and salinity fluctuations, Kolmogorov micro-scale, and rate of dissipation of the mean squared temperature) in detail. Results indicate that any change in the amount of turbulence factors that increase the turbulence power reduces the EWSDC significantly and causes the reduction in the degree of polarization, and occurs at shorter propagation distances but with smaller magnitudes. In addition, being valid for all conditions, the degradation rate of the EWSDC of Gaussian array beams are more in comparison with the PCFT ones. The simulation and calculation results are shown by graphs.

15.
Basic Res Cardiol ; 111(4): 52, 2016 07.
Article in English | MEDLINE | ID: mdl-27357950

ABSTRACT

Nitroglycerin (GTN) and other organic nitrates are widely used vasodilators. Their side effects are development of nitrate tolerance and endothelial dysfunction. Given the potential of GTN to induce nitro-oxidative stress, we investigated the interaction between nitro-oxidative DNA damage and vascular dysfunction in experimental nitrate tolerance. Cultured endothelial hybridoma cells (EA.hy 926) and Wistar rats were treated with GTN (ex vivo: 10-1000 µM; in vivo: 10, 20 and 50 mg/kg/day for 3 days, s.c.). The level of DNA strand breaks, 8-oxoguanine and O (6)-methylguanine DNA adducts was determined by Comet assay, dot blot and immunohistochemistry. Vascular function was determined by isometric tension recording. DNA adducts and strand breaks were induced by GTN in cells in vitro in a concentration-dependent manner. GTN in vivo administration leads to endothelial dysfunction, nitrate tolerance, aortic and cardiac oxidative stress, formation of DNA adducts, stabilization of p53 and apoptotic death of vascular cells in a dose-dependent fashion. Mice lacking O (6)-methylguanine-DNA methyltransferase displayed more vascular O (6)-methylguanine adducts and oxidative stress under GTN therapy than wild-type mice. Although we were not able to prove a causal role of DNA damage in the etiology of nitrate tolerance, the finding of GTN-induced DNA damage such as the mutagenic and toxic adduct O (6)-methylguanine, and cell death supports the notion that GTN based therapy may provoke adverse side effects, including endothelial function. Further studies are warranted to clarify whether GTN pro-apoptotic effects are related to an impaired recovery of patients upon myocardial infarction.


Subject(s)
DNA Damage , Drug Tolerance/physiology , Endothelium, Vascular/drug effects , Nitroglycerin/toxicity , Vasodilator Agents/toxicity , Animals , Blotting, Western , Comet Assay , Disease Models, Animal , Immunoblotting , Immunohistochemistry , Mice , Oxidative Stress , Rats , Rats, Wistar
16.
J Opt Soc Am A Opt Image Sci Vis ; 32(11): 1982-92, 2015 Nov 01.
Article in English | MEDLINE | ID: mdl-26560913

ABSTRACT

In this paper, on the basis of the extended Huygens-Fresnel principle, a semianalytical expression for describing on-axis scintillation index of a partially coherent flat-topped (PCFT) laser beam of weak to moderate oceanic turbulence is derived; consequently, by using the log-normal intensity probability density function, the bit error rate (BER) is evaluated. The effects of source factors (such as wavelength, order of flatness, and beam width) and turbulent ocean parameters (such as Kolmogorov microscale, relative strengths of temperature and salinity fluctuations, rate of dissipation of the mean squared temperature, and rate of dissipation of the turbulent kinetic energy per unit mass of fluid) on propagation behavior of scintillation index, and, hence, on BER, are studied in detail. Results indicate that, in comparison with a Gaussian beam, a PCFT laser beam with a higher order of flatness is found to have lower scintillations. In addition, the scintillation index and BER are most affected when salinity fluctuations in the ocean dominate temperature fluctuations.

17.
Pak J Biol Sci ; 10(1): 72-7, 2007 Jan 01.
Article in English | MEDLINE | ID: mdl-19069988

ABSTRACT

Greenhouse and laboratory experiments were performed to evaluate the resistant of wild oat Avena luduviciana Durieu. populations to fenoxaprop-p-ethyl. Populations of A. ludoviciana were collected from different locations in Iran, showed indications of resistance to this herbicide. Whole plant assay experiments included screening tests and dose response experiments whereas; seed bioassay experiment consisted of ID50 determination and dose response experiments. Whole plant assay experiments were conducted as a randomized complete block design in four replications. The treatments were wild oat populations included FR1, FR2, FR3, FR4 (collected from Fars province), MR1, MR2, MR3 (collected from Markazi province), KS, KR1, KR2, KR3 (collected from Khuzestan province) and S (collected from location which had never been treated previously with any graminicide). Seed bioassay experiments were conducted using a randomized design with 4 replications. On the whole plant basis, resistance was found in, KR1, KR2, KR3 and FR4 and based on a seed bioassay, these populations were also resistant to fenoxaprop-p-ethyl. Resistance ratios (R/S) of resistant populations were different. Present findings also revealed that the seed bioassay could be used as a simple, comparatively rapid, inexpensive and accurate method for identifying wild oat populations resistant to Acetyl CoA carboxylase (ACCase) inhibitors.


Subject(s)
Avena/drug effects , Biological Assay/methods , Oxazoles/pharmacology , Propionates/pharmacology , Seeds/drug effects , Avena/metabolism , Dose-Response Relationship, Drug , Herbicides/pharmacology , Seeds/metabolism
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