326 research outputs found

    Numerical Study of Reinforced Concrete Beam by Using ABAQUS Software

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    Cracks are serious problems in the structural characteristics of a concrete structure due to several failure modes such as, flexural and shear. Reinforced concrete behaviour is complicated, and for a realistic simulation of such behaviour a prober material modelling has to be used.  In this work an attempt has been made to simulate concrete and embedded reinforcement steel to predict the crack propagation in RC beam using a plastic damage behaviour by ABAQUS software. The proposed modelling has been validated against experimental results found in the literature. The results have shown that displacement associated with ultimate load is in a good agreement with experiment, as well as the failure load. The crack pattern indicated that the cracks will start from the tension zone in the bottom of RC beam and extended to top of beam

    Ability of a Local Bacillus cereus DS1 Isolate of Dematallization of Heavy Metals

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    Bacillus cereusDS1 isolate obtained from oil contaminated soil sample, has been isolated in the previous experiments. It was selected for its ability to degrade Nickel protoporphyrin disodium as a model of a heavy metal organic compound .In this research we report capability of the bacterial isolate of growing on Vanadium oxide octaethyl porphyrin with concentration of 20 mg / l as a carbon source. Result showed less efficiency to grow with existence of this substrate .Effect of other compounds used as a chloride metals was investigated .Bacterial strain exhibited a deferent pattern of growth with addition of this metals .The results shown an obvious growth inhibition in state of using Zn metal, when added Cu stimulated the growth activity. Such isolate can be interesting in improving oil quality. Keywords: bacteria, protoporphyrins, heavy metals, dematallization and crud oil

    Ability of a Local Bacillus cereus DS1 Isolate of Dematallization of Heavy Metals

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    Bacillus cereusDS1 isolate obtained from oil contaminated soil sample, has been isolated in the previous experiments. It was selected for its ability to degrade Nickel protoporphyrin disodium as a model of a heavy metal organic compound .In this research we report capability of the bacterial isolate of growing on Vanadium oxide octaethyl porphyrin with concentration of 20 mg / l as a carbon source. Result showed less efficiency to grow with existence of this substrate .Effect of other compounds used as a chloride metals was investigated .Bacterial strain exhibited a deferent pattern of growth with addition of this metals .The results shown an obvious growth inhibition in state of using Zn metal, when added Cu stimulated the growth activity. Such isolate can be interesting in improving oil quality. Keywords: bacteria, protoporphyrins, heavy metals, dematallization and crud oil

    Exploring noise effects in chaotic optical networks

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    We report the experimental evidence coherence and stochastic resonance in a dynamics of fast chaotic spiking of a semiconductor laser with optical feedback using an external nonwhite noise in the pumping current. We characterize both coherence and stochastic resonance in the time and frequency domain. We show that the regularity of the chaotic pulses in the intensity of laser diod increases when adding noise and it is optimal for some intermediate value of the noise intensity. We find that the power spectrum of the signal develops a peak at a finite frequency at intermediate values of the noise. The results show that noise may help in extracting the periodic signal without synchronization in chaotic communication. Then we reported the effect of external noise numerically on a single system by using bifurcation diagram. Finally, we considered Chaos synchronization in a network of 28 distinct chaotic systems with independent initial conditions when a normal Gaussian noise is added. The transition between non-synchronization to synchronization states using a suitable spatio-temporal representation has been reported. The role of coherence has also been considered. Keywords: Coherence resonance, Stochastic resonance, Control, Nois

    Diet-induced gene expression of isolated pancreatic islets from a polygenic mouse model of the metabolic syndrome

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    AIMS/HYPOTHESIS: Numerous new genes have recently been identified in genome-wide association studies for type 2 diabetes. Most are highly expressed in beta cells and presumably play important roles in their function. However, these genes account for only a small proportion of total risk and there are likely to be additional candidate genes not detected by current methodology. We therefore investigated islets from the polygenic New Zealand mouse (NZL) model of diet-induced beta cell dysfunction to identify novel genes and pathways that may play a role in the pathogenesis of diabetes. METHODS: NZL mice were fed a diabetogenic high-fat diet (HF) or a diabetes-protective carbohydrate-free HF diet (CHF). Pancreatic islets were isolated by laser capture microdissection (LCM) and subjected to genome-wide transcriptome analyses. RESULTS: In the prediabetic state, 2,109 islet transcripts were differentially regulated (>1.5-fold) between HF and CHF diets. Of the genes identified, 39 (e.g. Cacna1d, Chd2, Clip2, Igf2bp2, Dach1, Tspan8) correlated with data from the Diabetes Genetics Initiative and Wellcome Trust Case Control Consortium genome-wide scans for type 2 diabetes, thus validating our approach. HF diet induced early changes in gene expression associated with increased cell-cycle progression, proliferation and differentiation of islet cells, and oxidative stress (e.g. Cdkn1b, Tmem27, Pax6, Cat, Prdx4 and Txnip). In addition, pathway analysis identified oxidative phosphorylation as the predominant gene-set that was significantly upregulated in response to the diabetogenic HF diet. CONCLUSIONS/INTERPRETATION: We demonstrated that LCM of pancreatic islet cells in combination with transcriptional profiling can be successfully used to identify novel candidate genes for diabetes. Our data strongly implicate glucose-induced oxidative stress in disease progression

    Alternative exon splicing and differential expression in pancreatic islets reveals candidate genes and pathways implicated in early diabetes development

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    Type 2 diabetes (T2D) has a strong genetic component. Most of the gene variants driving the pathogenesis of T2D seem to target pancreatic β-cell function. To identify novel gene variants acting at early stage of the disease, we analyzed whole transcriptome data to identify differential expression (DE) and alternative exon splicing (AS) transcripts in pancreatic islets collected from two metabolically diverse mouse strains at 6 weeks of age after three weeks of high-fat-diet intervention. Our analysis revealed 1218 DE and 436 AS genes in islets from NZO/Hl vs C3HeB/FeJ. Whereas some of the revealed genes present well-established markers for β-cell failure, such as Cd36 or Aldh1a3, we identified numerous DE/AS genes that have not been described in context with β-cell function before. The gene Lgals2, previously associated with human T2D development, was DE as well as AS and localizes in a quantitative trait locus (QTL) for blood glucose on Chr.15 that we reported recently in our N2(NZOxC3H) population. In addition, pathway enrichment analysis of DE and AS genes showed an overlap of only half of the revealed pathways, indicating that DE and AS in large parts influence different pathways in T2D development. PPARG and adipogenesis pathways, two well-established metabolic pathways, were overrepresented for both DE and AS genes, probably as an adaptive mechanism to cope for increased cellular stress. Our results provide guidance for the identification of novel T2D candidate genes and demonstrate the presence of numerous AS transcripts possibly involved in islet function and maintenance of glucose homeostasis

    Baghdad’s thirdspace: Between liminality, anti-structures and territorial mappings

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    Wedged in-between the dense urban grain of Baghdad, blast walls of t-shaped concrete have littered the streets and neighbourhoods since 2003, after the US led invasion. The idiosyncrasy of these walls lies in their exaggerated spatial liminality. They appear, change location and disappear overnight, and on a daily basis, leaving Iraqis to navigate through labyrinths of in-between spaces. This article critically reveals the new social and power structures that have emerged in the context of the city in response to the condition resulting from this unique urban intervention. This uncanny spatial and social condition of permanent liminality will be analysed through Victor Turner’s critical theories of liminality and anti-structure coupled with Edward Soja’s theory of Thirdspace, interpreting, through a series of territorial mappings, a complex liminal condition in a contested and disrupted city

    In vitro pharmacology of fentanyl analogs at the human mu opioid receptor and their spectroscopic analysis

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    Opioids are widely misused and account for almost half of overdose deaths in the United States. The cost in terms of lives, health care, and lost productivity is significant and has been declared a national crisis. Fentanyl is a highly potent mu opioid receptor (MOR) agonist and plays a significant role in the current opioid epidemic; fentanyl and its analogs (fentalogs) are increasingly becoming one of the biggest dangers in the opioid crisis. The availability of fentalogs in the illicit market is thought to play a significant role in the recent increase in opioid‐related deaths. Although there is both rodent homolog in vivo and in vitro data for some fentalogs, prior to this publication very little was known about the pharmacology of many of these illicit compounds at the human MOR (hMOR). Using gas chromatography–mass spectrometry, nuclear magnetic resonance spectroscopy, and in vitro assays, this study describes the spectral and pharmacological properties of 34 fentalogs. The reported spectra and chemical data will allow for easy identification of novel fentalogs in unknown or mixed samples. Taken together these data are useful for law enforcement and clinical workers as they will aid in the identification of fentalogs in unknown samples and can potentially be used to predict physiological effects after exposure.This study reports the basic in vitro pharmacology (affinity, agonist activity, and potencies) of 34 fentanyl analogs at the human mu opioid receptor. In addition, these fentalogs are analyzed spectroscopically using gas chromatography–mass spectrometry and proton nuclear magnetic resonance spectroscopy, to understand structural commonalities and key differences for identification.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156439/2/dta2822.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156439/1/dta2822_am.pd

    Impact of dispersion media and carrier type on spray-dried proliposome powder formulations loaded with beclomethasone dipropionate for their pulmonary drug delivery via a next generation impactor

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    Drug delivery via aerosolization for localized and systemic effect is a non-invasive approach to achieving pulmonary targeting. The aim of this study was to prepare spray-dried proliposome (SDP) powder formulations to produce carrier particles for superior aerosolization performance, assessed via a next generation impactor (NGI) in combination with a dry powder inhaler. SDP powder formulations (F1-F10) were prepared using a spray dryer, employing five different types of lactose carriers (Lactose monohydrate (LMH), lactose microfine (LMF), lactose 003, lactose 220 and lactose 300) and two different dispersion media. The first dispersion medium was comprised of water and ethanol (50:50% v/v ratio), and the second dispersion medium comprised wholly of ethanol (100%). In the first dispersion medium, the lipid phase (consisting of Soya phosphatidylcholine (SPC as phospholipid) and Beclomethasone dipropionate (BDP; model drug) were dissolved in ethanol and the lactose carrier in water, followed by spray drying. Whereas in second dispersion medium, the lipid phase and lactose carrier were dispersed in ethanol only, post spray drying. SDP powder formulations (F1-F5) possessed significantly smaller particles (2.89 ± 1.24-4.48 ± 1.20 μm), when compared to SDP F6-F10 formulations (10.63 ± 3.71-19.27 ± 4.98 μm), irrespective of lactose carrier type via SEM (scanning electron microscopy). Crystallinity of the F6-F10 and amorphicity of F1-F15 formulations were confirmed by XRD (X-ray diffraction). Differences in size and crystallinity were further reflected in production yield, where significantly higher production yield was obtained for F1-F5 (74.87 ± 4.28-87.32 ± 2.42%) then F6-F10 formulations (40.08 ± 5.714-54.98 ± 5.82%), irrespective of carrier type. Negligible differences were noted in terms of entrapment efficiency, when comparing F1-F5 SDP formulations (94.67 ± 8.41-96.35 ± 7.93) to F6-F10 formulations (78.16 ± 9.35-82.95 ± 9.62). Moreover, formulations F1-F5 demonstrated significantly higher fine particle fraction (FPF), fine particle dose (FPD) and respirable fraction (RF) (on average of 30.35%, 890.12 μg and 85.90%) when compared to counterpart SDP powder formulations (F6-F10). This study has demonstrated that when a combination of water and ethanol was employed as dispersion medium (formulations F1-F5), superior formulation properties for pulmonary drug delivery were observed, irrespective of carrier type employed
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