868 research outputs found

    Intrinsic non-uniqueness of the acoustic full waveform inverse problem

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    SUMMARY In the context of seismic imaging, full waveform inversion (FWI) is increasingly popular. Because of its lower numerical cost, the acoustic approximation is often used, especially at the exploration geophysics scale, both for tests and for real data. Moreover, some research domains such as helioseismology face true acoustic media for which FWI can be useful. In this work, an argument that combines particle relabelling and homogenization is used to show that the general acoustic inverse problem based on band-limited data is intrinsically non-unique. It follows that the results of such inversions should be interpreted with caution. To illustrate these ideas, we consider 2-D numerical FWI examples based on a Gauss–Newton iterative inversion scheme and demonstrate effects of this non-uniqueness in the local optimization context.</jats:p

    Gene Expression and Methylation Levels of PCSK9 Gene in Iraqi Patients with Coronary Artery Disease

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    يرتبط التعبير الجيني لجين  PCSK9ارتباطًا وثيقًا بمستويات الدهون وخطر الإصابة بمرض تصلب الشرايين التاجية. تهدف الدراسة الحالية إلى قياس كمية التعبير الجيني للجين PCSK9 وتأثير المثيلة على مستوى تعبيره الذي يساهم في التسبب في اضطراب الشريان التاجي الحاد. تضمنت الدراسة الحالية 150 شخصًا من المجتمع العراقي ، 100 مريض بمرض الشريان التاجي و 50 من الأصحاء. تم تحديد تركيز PCSK9 في كل عينات المصل المدروسة بواسطة تقنية ELISA ، وتم تقدير مستويات التعبير عن جين PCSK9 في الدم الكامل بطريقة qRT-PCR ، واكتشاف مستوى مثيلة الحمض النووي في جين PCSK9 باستخدام تقنية HRM-PCR. كان التعبير عن جين ب مستوى اعلى  PCSK9 6.06 ± 1.84 في مجموعة مرضى ASCAD مقارنة بمجموعة التحكم 1.00 ± 0.19. أيضا كان تركيز بروتين PCSK9 عالياً في مجموعة المرضى مقارنة بمجموعة الاصحاء P = &lt;0.01. فضلا عن ان مستويات مثيلة PCSK9 ، اظهرت فرقاً معنوياً بين مجموعتي الدراسة بمستوى 0.002P=. في الختام ، ترتبط مستويات بروتين PCSK9 في المصل بمرض الشريان التاجي كما موضح في receiver operating characteristic (ROC) analysis ، مما يؤدي إلى اعتبار أن تركيز بروتين PCSK9  قد يكون مؤشرًا جيدًا لتطور مرض الشريان التاجي.The expression of the Proprotein Convertase Subtilisin/Kexin Type 9 gene (PCSK9) is inextricably related to lipid levels and a risk of atherosclerotic coronary artery disease (ASCAD). The present study aims to measure the quantity of PCSK9 gene expression and the effect of methylation on its expression level taking part in the pathogenesis of acute coronary artery disorder. A current study included 150 subjects from the Iraqi population, 100 ASCAD patients and 50 healthy controls. The concentration of PCSK9 in each serum sample was determined by the ELISA technique, the expression levels of the PCSK9 gene in whole blood were estimated by RT-qPCR – Quantitative Reverse Transcription PCR method, and DNA methylation level detection in PCSK9 gene by using High Resolution Melting Analysis (HRM) technique. The expression level of the PCSK9 gene was 6.06 ± 1.84 in ASCAD patients group compared with a control group 1.00 ±0.19. That indicates the up-regulation of the PCSK9 gene in patient with atherosclerosis. In addition, the PCSK9 concentration was higher in patient group in comparison to the healthy controls group P= &lt; 0.01. However, PCSK9 methylation levels, a highly significant distinction between the two study groups p=0.002. In conclusion, serum PCSK9 levels are associated with coronary artery lesions as shown in receiver operating characteristic (ROC) analysis. Suggests that, serum PCSK9 might be a good indicator of coronary artery disease development

    Sulfonyl-Substituted Heteroleptic Cyclometalated Iridium(III) Complexes as Blue Emitters for Solution-Processable Phosphorescent Organic Light-Emitting Diodes

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    The synthesis is reported of a series of blue-emitting heteroleptic iridium complexes with phenylpyridine (ppy) ligands substituted with sulfonyl, fluorine, and/or methoxy substituents on the phenyl ring and a picolinate (pic) ancillary ligand. Some derivatives are additionally substituted with a mesityl substituent on the pyridyl ring of ppy to increase solubility. Analogues with two ppy and one 2-(2′-oxyphenyl)pyridyl (oppy) ancillary ligand were obtained by an unusual in situ nucleophilic displacement of a fluorine substituent on one of the ppy ligands by water followed by N^O chelation to iridium. The X-ray crystal structures of seven of the complexes are reported. The photophysical and electrochemical properties of the complexes are supported by density functional theory (DFT) and time-dependent DFT calculations. Efficient blue phosphorescent organic light-emitting devices (PhOLEDs) were fabricated using a selection of the complexes in a simple device architecture using a solution-processed single-emitting layer in the configuration ITO/PEDOT:PSS/PVK:OXD-7(35%):Ir complex(15%)/TPBi/LiF/Al. The addition of a sulfonyl substituent blue-shifts the electroluminescence by ca. 12 nm to λmaxEL 463 nm with CIEx,y coordinates (0.19, 0.29), compared to the benchmark complex FIrpic (λmaxEL 475 nm, 0.19, 0.38) in directly comparable devices, confirming the potential of the new complexes to serve as effective blue dopants in PhOLEDs. Replacing a fluorine by a methoxy group in these complexes red shifts the PL and EL λmax by ca. 4–6 nm. The efficiency of the blue PhOLEDs of the sulfonyl-substituted complexes is, in most cases, significantly enhanced by the presence of a mesityl substituent on the pyridyl ring of the ppy ligands

    AUTOMATED MEASUREMENT AND SYSTEM DATA LOGGER FOR CONTINUOUS MONITORING OF SLICED BANANA FRUIT DURING DRYING PROCESS BY A SOLAR HOT- AIR DRYER

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    The aim of this work is developing and evaluating an automated measurement and system datalogger for continuous monitoring of solar hot air drier for natural convection solar cabinet drier. Measurements includes monitoring of drying process for sliced Banana (Musa acuminata) relation to weather parameters such as ambient air temperature, relative humidity and wind velocity which ensures precise measurements and reproduction of experiments. An electronic measurement system was used for measurement of temperature, humidity, air speed, a solar intensity. A programmable microcontroller ship and code were used to control measurement, timing, and data storage twenty-four hours/day. All measurements data was collected and saved in storage memory card. Results showed that the solar drier drying rate achieved (-0.018gH2O/g dm.h), while the drying rate with mean of electrical thermal drier were  (-0.956 018gH2O/gdm.h) at 105°C, (-0.552 018gH2O/g dm.h) at 70°C and (-0.513 018gH2O/gdm.h) at 50°C. The electronic measurement - datalogging system was able to give an accurate measurement and assessment to the drying system and process. It was found that air leakage from the system and poor insulation inhibit the airflow over the solar absorber plate and drying chamber causing thermal leakage form the bottom and drier sides. It was recommended to supply the solar drier with an air fan, seal the drying air leakage, and air-lock at the entrance to control airflow as well as the temperature of the drying process

    Osmolyte regulation by TonEBP/NFAT5 during anoxia-recovery and dehydration- rehydration stresses in the freeze-tolerant wood frog (Rana sylvatica)

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    Background. The wood frog, Rana sylvatica, tolerates freezing as a means of winter survival. Freezing is considered to be an ischemic/anoxic event in which oxygen delivery is significantly impaired. In addition, cellular dehydration occurs during freezing because water is lost to extracellular compartments in order to promote freezing. In order to prevent severe cell shrinkage and cell death, it is important for the wood frog to have adaptive mechanisms for osmoregulation. One important mechanism of cellular osmoregulation occurs through the cellular uptake/production of organic osmolytes like sorbitol, betaine, and myo-inositol. Betaine and myo-inositol are transported by the proteins BGT-1 and SMIT, respectively. Sorbitol on the other hand, is synthesized inside the cell by the enzyme aldose reductase. These three proteins are regulated at the transcriptional level by the transcription factor, NFAT5/TonEBP. Therefore, the objective of this study was to elucidate the role of NFAT5/TonEBP in regulating BGT-1, SMIT, and aldose reductase, during dehydration and anoxia in the wood frog muscle, liver, and kidney tissues. Methods. Wood frogs were subjected to 24 h anoxia-4 h recovery and 40% dehydration- full rehydration experiments. Protein levels of NFAT5, BGT-1, SMIT, and aldose reductase were studied using immunoblotting in muscle, liver, and kidney tissues. Results. Immunoblotting results demonstrated downregulations in NFAT5 protein levels in both liver and kidney tissues during anoxia (decreases by 41% and 44% relative to control for liver and kidney, respectively). Aldose reductase protein levels also decreased in both muscle and kidney tissues during anoxia (by 37% and 30% for muscle and kidney, respectively). On the other hand, BGT-1 levels increased during anoxia in muscle (0.9-fold compared to control) and kidney (1.1-fold). Under 40% dehydration, NFAT5 levels decreased in liver by 53%. Aldose reductase levels also decreased by 42% in dehydrated muscle, and by

    Management of chest keloids

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    Keloid formation is one of the most challenging clinical problems in wound healing. With increasing frequency of open heart surgery, chest keloid formations are not infrequent in the clinical practice. The numerous treatment methods including surgical excision, intralesional steroid injection, radiation therapy, laser therapy, silicone gel sheeting, and pressure therapy underscore how little is understood about keloids. Keloids have a tendency to recur after surgical excision as a single treatment. Stretching tension is clearly associated with keloid generation, as keloids tend to occur on high tension sites such as chest region. The authors treated 58 chest keloid patients with surgical excision followed by intraoperative and postoperative intralesional steroid injection. Even with minor complications and recurrences, our protocol results in excellent outcomes in cases of chest keloids

    Relating quantitative 7T MRI across cortical depths to cytoarchitectonics, gene expression and connectomics

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    Ultra‐high field MRI across the depth of the cortex has the potential to provide anatomically precise biomarkers and mechanistic insights into neurodegenerative disease like Huntington's disease that show layer‐selective vulnerability. Here we compare multi‐parametric mapping (MPM) measures across cortical depths for a 7T 500 μm whole brain acquisition to (a) layer‐specific cell measures from the von Economo histology atlas, (b) layer‐specific gene expression, using the Allen Human Brain atlas and (c) white matter connections using high‐fidelity diffusion tractography, at a 1.3 mm isotropic voxel resolution, from a 300mT/m Connectom MRI system. We show that R2*, but not R1, across cortical depths is highly correlated with layer‐specific cell number and layer‐specific gene expression. R1‐ and R2*‐weighted connectivity strength of cortico‐striatal and intra‐hemispheric cortical white matter connections was highly correlated with grey matter R1 and R2* across cortical depths. Limitations of the layer‐specific relationships demonstrated are at least in part related to the high cross‐correlations of von Economo atlas cell counts and layer‐specific gene expression across cortical layers. These findings demonstrate the potential and limitations of combining 7T MPMs, gene expression and white matter connections to provide an anatomically precise framework for tracking neurodegenerative disease

    Relating quantitative 7T MRI across cortical depths to cytoarchitectonics, gene expression and connectomics

    Get PDF
    Ultra-high field MRI across the depth of the cortex has the potential to provide ana- tomically precise biomarkers and mechanistic insights into neurodegenerative disease like Huntington's disease that show layer-selective vulnerability. Here we compare multi-parametric mapping (MPM) measures across cortical depths for a 7T 500 m whole brain acquisition to (a) layer-specific cell measures from the von Economo his- tology atlas, (b) layer-specific gene expression, using the Allen Human Brain atlas and (c) white matter connections using high-fidelity diffusion tractography, at a 1.3 mm isotropic voxel resolution, from a 300mT/m Connectom MRI system. We show that R2*, but not R1, across cortical depths is highly correlated with layer-specific cell number and layer-specific gene expression. R1- and R2*-weighted connectivity strength of cortico-striatal and intra-hemispheric cortical white matter connections was highly correlated with grey matter R1 and R2* across cortical depths. Limitations of the layer-specific relationships demonstrated are at least in part related to the high cross-correlations of von Economo atlas cell counts and layer-specific gene expres- sion across cortical layers. These findings demonstrate the potential and limitations of combining 7T MPMs, gene expression and white matter connections to provide an anatomically precise framework for tracking neurodegenerative disease

    EFFECT OF STRAIN, SEASON AND BREEDER'S AGE ON SOME PHYSIOLOGICAL PARAMETERS FOR LAYER DEAD EMBRYO

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    The effect of breederʼs strain (Hy-line Brown and Hy-line White W36) flock aged (28, 36, 46, 55, 66 weeks of age) and breeding season on some physiological measurements in egg, demand organs, dead supply organs and lymphoid organs were examined. At each age, 10 unhatched eggs from each genotype were examined on embryo weight percentage, Chorioallotoic  weight %, albumen pH %, yolk pH %, residual yolk %, pectoral  muscles weight %, hatch muscles weight %, heart, liver, lunges, spleen, burse weight percentage. There was a significant difference between layer breeder genotypes for lunges weight percentage the brown was higher (0.84) than the white (0.62). The breeding season had a significant effect on heart, liver, lunges weight percentages in winter higher than summer but yolk pH and residual yolk the summer higher than the winter. Breeder's age significant effect on embryo weight percentage, Chorioallotoic weight %, albumen pH %, yolk pH%, residual yolk %, hatch muscles weight % heart, liver, lunges and burse weight percentage.  It could be observed that the genetic differences among layer breeder strain and age of breeders can affect the hatchery performance. Additionally, handling of hatching eggs and incubation management can play a major role to overcome numerous hatching problems. In turn, increasing the production of table eggs and achieves the balance between supply and demand of that strategic commodity in Egyptian market
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