19 research outputs found
Role of Stearoyl-CoA desaturase-1 (SCD1) in the activation of epidermal growth factor receptor (EGFR) in lung cancer cells
No full textCancer cells activate lipogenic enzymes, including StearoylCoA Desaturase-1 (SCD1), the key enzyme that converts saturated fatty acids (SFA) into monounsaturated fatty acids (MUFA). Previously, we established that SCD1 regulates lipogenesis, cell proliferation and invasiveness in lung cancer cells, as well as tumor formation in mice. We recently reported that SCD1 modulates the PI3K/Akt pathway, a central signaling cascade, along with ERK, which are involved in the regulation of lipid biosynthesis, growth and survival of mammalian cells. Growth factor-activated tyrosine kinase receptors, such as epidermal growth factor (EGF) receptors (EGFR), are main activators of Akt and ERK signals, two cascades that are most often deranged in cancer. A hallmark of cancer is the metabolic shift towards macromolecular synthesis to support cell replication. SCD1 expression increases in cancer cells. The molecular mechanisms by which SCD1 regulates the biological phenotype of cancer cells is still unknown. The poor prognosis and ineffective treatments of some cancers, such as lung cancer, calls for better understanding of their mechanisms and for finding novel targets that, like SCD1, modulate the Akt and ERK pathways. Here we provide evidence that SCD1 activity controls the activation of EGFR and its downstream signaling targets, Akt and ERK. Using H460 human lung cancer cells, we observed that the activating phosphorylation of Tyr1068 and Tyr1086 residues in EGFR upon EGF stimulation was markedly impaired when SCD1 activity was blocked with CVT-11127, a novel small molecule SCD inhibitor. In addition, supplementation with oleic acid, the product of SCD1, restored EGF-induced phosphorylation of EGFR but not the full phosphorylation of Akt. Finally, abrogation of SCD1 dramatically altered distribution of rafts and non-raft domains, suggesting that the regulation of EGFR function by SCD1 may involve the alteration of membrane lipid domains. All results are representative of 3 separate experiments. In conclusion, our data indicate that SCD1 may coordinate the regulation of lipid biosynthesis and the transduction signals that control cancer cell metabolism, proliferation, survival and tumorigenesis by modulating EGFR activation, which subsequently modifies the Akt and ERK signaling platforms. Our findings also suggest SCD1 is a potential target for novel pharmacological interventions in lung cancer.M.S.Includes bibliographical referencesby Mary Nashe
GIS and geotechnical mapping of expansive soil in Toshka region
No full textAbstractThis paper presents the results of a subsurface site investigation that was performed to characterize different soil and rock formations along Sheikh Zayed canal with particular emphasis on the swelling characteristics of the clays in that area. Site-specific empirical correlations were developed to predict the clay swelling potential and pressure from simple and economic laboratory test results. The data were input into a Geographic Information System (GIS) framework to provide interactive maps that show the spatial distribution of the variables and identify their characteristics. These maps are then used to easily identify the values of swelling pressure/potential at various locations. This research provides a tool that is based on simple index tests that can be used to provide data that otherwise would require elaborate and costly investigations; the GIS framework allows storing, retrieving and updating these data easily to assist taking supported decisions dynamically
Polymer-clay Nanocomposites
No full textPhDPolymer-clay nanocomposites are attracting global interest principally because
property enhancements are obtained at low clay particle loadings (1-5 wt%).
However there is lack of fundamental understanding of such composites. The aim
of this work is to provide an insight into the interaction between polymer and clay.
This includes the driving force for intercalation, the reinforcement mechanisms and
property-volume fraction relationships.
Functionalised poly(ethylene glycol)-clay, poly(c-caprolactone)-clay and
thermoplastic starch-clay nanocomposites with a range of polymer molecular
weights, clay volume fractions and with different clays were prepared using
solution methods, melt-processing methods, and in situ polymerisation. A reliable
X-ray diffraction technique for low angle basal plane spacing of clay, the essential
parameter for structure determination, was established obtaining ±0.005 Mn
between three diffractometers. The basal plane spacing was found to be unaffected
by polymer molecular weight and preparation method but was affected by the
nature of the polymer and clay. Increasing clay loading could lead to a lower
spacing. As a cautionary observation, poly(ethylene glycol) with high molecular
weight (2: 10,000) was found to undergo degradation readily during preparation of
nanocomposites with and without clay.
Competitive sorption experiments for molecular weight showed that high
molecular weight fractions of polymer intercalate preferentially into clay during
solution preparation. Thermodynamic studies on the intercalation process found
that significant enthalpic change occurred during intercalation, which is coincident
with the observation that heat-treated clays without interlayer water can intercalate
polymer. The calculation of true volume fraction against nominal volume fraction
provided reasonable explanation of property enhancement and helps understand the
relation between nanocomposites and conventional composites. At a given clay
loading, nanocomposites with better dispersion gave more property enhancement
than those with lower dispersion or conventional composites. The crystallinity of
semicrystalline polymer was also affected by varying extents of dispersion of clay.
The use of X-ray diffraction with an internal standard was explored for quantitative
analysis of intercalation and exfoliation
Maxwell-f(Q) Theory
No full textExploring the four-dimensional AdS black hole is crucial within the framework of the AdS/CFT correspondence. In this research, four-dimensional stationary and rotating AdS solutions in the framework of the (Formula presented.) gravitational theory are investigated, considering the charged scenario. Author\u27s emphasis is on the power-law ansatz, which consistent with observations and is deemed the most viable. Because this solution does not have an uncharged version or relate to general relativity, it falls into a new category, which derives its features from changes in non-metricity and incorporates the Maxwell domain. The singularities of such a solution are analyzed, computing all the quantities of different curvature and non-metricity invariants. Author\u27s results indicate the presence of a central singularity, albeit with a softer nature compared to standard non-metricity or Einstein general relativity, attributed to the influence of the effect of (Formula presented.). Several physical characteristics of black hole from thermodynamics perspective and demonstrate the existence of an outer event horizon in addition to the inner Cauchy horizons are examined. However, under the conditions of sufficiently large electric charge, a naked singularity emerges. Finally, a class of rotating black hole in four-dimensional (Formula presented.) gravity that are asymptotically anti-de Sitter charged is derived
Innovative Bio-nanocomposites Based on Bacterial Cellulose
No full textPhDA variety natural materials that are environmentally friendly, renewable and low cost
have been created. Bacterial cellulose (BC), which is produced by a harmless
bacterium, Acetobacter xylinum, has been used as a reinforcement agent to form bionanocomposites.
Apple and radish pulp which are themselves cellulosic, were
blended with bacterial cellulose to produce a high quality nanopaper which can be
used for special purposes. The resulting sheets are characterised in terms of their
morphology as well as their mechanical and thermal properties. Another approach
adopted was the combination of BC with bio-polymers such as poly (ε-caprolactone)
and a commercially available starch based polymer, Mater-Bi. Freeze-dried BC,
which was kept in its 3D shape, was used as a comparison. These innovative
composite systems are non-petroleum based and are biodegradable. The morphology,
structure, thermal properties and performance of the resulting bio-composites were
investigated using scanning electron microscopy, Fourier Transform Infrared
spectroscopy, Differential Scanning Calorimetry, Dynamic Mechanical Analysis, and
by measuring the mechanical properties. Purification is a crucial step in removing
impurities and another organic materials remaining in the BC. The BC gel which was
purified in two steps, i.e. with 2.5 wt.% NaOH and then bleaching with 2.5 wt.%
NaOCl respectively, showed a greater performance in its thermal and mechanical
properties. In addition, it was shown that the cellulose I structure of BC is not
converted to cellulose II. BC is an interesting material for in-vivo studies. However,
to make it an interesting biological composite a suitable resin must be found. Poly
(vinyl alcohol) (PVA) is a known water soluble polymer and is therefore a suitable
candidate material. In this study BC was grown in PVA solution to produce an in-situ
composite. The concluding work for this project is an in-vitro study of BC for
scaffolds for tissue engineering. The BC network was seeded with bovine
chondrocytes (bone cells) obtained from an 18 months old deer and cultured into the
BC gel to establish the viability of this material for medical applications
An investigation and study from the chapter of divorce of the patient to the chapter of seizure from the book "Tuhfat al-Akhayyar Ala al-Dur al-Mukhtar" which was written by Abu al-Safa Burhan al-Din Ibrahim bin Mustafa al-Halabi
No full textBu çalışma İstanbul Sebahattin Zaim üniversitesinde İslami ilimler programı yüksek lisans derecesi kazanmak için takdim edilmiş ilmi bir çalışmadır. Tez konumuzun başlığı Ebü'l-Sefâ Burhânüddîn İbrâhîm b. Mustafa el-Halebî'nin Tuhfetü'l-Ahyâr alâ Dürrü'l-mu'târ eserinden "talâkul merîz babından istîlâ babına kadar olan bölümün tahkik ve incelemesini teşkil etmektedir. Tuhfetü'l-Ahyâr, Muhammed b. Abdullah et-Timurtaşî'nin Tenvîrü'l-eb'âr adlı eserine Haskefî'nin ed-Dürrü'l-mu'târ adıyla yazdığı şerh üzerine yazılmış bir hâşiyedir. El-Halebî haşiyesinde kapalı ibareleri açıklamış, problemli yerlere notlar düşmüş, bazen tashih bazen beyan bazense tasvipte bulunmuştur. Halebî'nin bu haşiyesi bu kitap üzerine yazılmış haşiyelerin en önemlilerindendir. Arzu edilen amaca yönelik en faydalı, kabul gören bir düzene sahip, mümkün olduğunca doğru görüşler belirtilmiştir. Yazar, eserindeki itiraz tashih ve düzeltmelerde ulemaya karşı saygısını korumuştur. Tahkik edilen bölüme talâk kitabından bir miktar, ricat, îlâ, Hulu, zihar, li'ân, anin ve iddet bablarından ayrıca itk kitabından da bir bölüm ilave etmiştir. Çalışmamı iki ana bölüme ayırdım; Bir: inceleme İki: seçili bölümün tahkiki Tüm bunları inşallah yeri geldikçe açıklayacağım. Yüce Rabbimden takdim ettiğim çalışmamın bana fayda sağlamasını niyaz ediyorum. İmam el-Halebî'ye ilim ve ilim ehline sağladığı katkılardan ötürü mükafatların en hayırlısını bahşetmesini diliyorum. Rabbimden bu çalışmamı yazarın Murad ettiği incelikleri tespit ederek itmam etme konusunda yardım talep ediyorum. Rabbul âlemin her şeye gücü yeten ve her şeyin sahibidir.This Scientific Thesis Was Prepared In An Effort To Obtain A Master's Degree In The Islamic Studies Program At The Istanbul Sabahattin Zaim University. It Is Titled "An Investigation And Study From The Chapter Of Divorce Of The Patient To The Chapter Of Seizure" From The Book "Tuhfat Al-Akhayyar Ala Al-Dur Al-Mukhtar" Which Was Written By Abu Al-Safa Burhan Al-Din Ibrahim Bin Mustafa Al-Halabi. Tuhfat Al-Akhayyar Is An Annotation Placed On "Al-Durr Al-Mukhtar" By Ala Al-Din Al-Hasakfi In His Commentary On Tanwir Al-Absar By Muhammad Al-Tamrtashi. Al-Halabi Has Explained In His Annotation The Ambiguous Phrases And Commented On The Touchy Issues As Well As Added Some Corrections. That Is Why Al-Habibi's Explanation Was One Of The Most Important Annotations To This Book. It Served A Great Purpose And Coordinated An Acceptable Method Of Making Corrections. He Was As Polite And Humble With The Scholars In His Objection, Criticism And Correction. This Investigative Thesis Has Included Some Of The Divorce Chapter, The Chapters Of Rajah, Lla, Khule, Zihar, Li'an. Eanan, Iddah And Some Of The Manumission Chapter. I Divided The Thesis Into Two Parts. First, Being The Study Of The Content And The Second Being The Investigation Of The Assigned Section. This Will Be Explained In Detail Within The Thesis, Allah Willing. Finally, I Ask Allah Almighty To Benefit Me From What I Have Endeavored Upon, And To Reward Imam Al-Halabi For His Knowledge The Best Reward, And To Help Me To Produce This Thesis Accurately As It Was Desired By It's Author
Physical-chemical Properties of Aqueous TBAOH Solution for Gas Hydrates Promotion
No full textAbstractGas hydrates attract the attention of many industries for various potential applications such as gas separation and storage. To industrialize the gas hydrate technology, rapid hydrate formation at mild conditions is crucial. Chemical additives such as ionic liquids were investigated for hydrate promotion. The knowledge of physical-chemical properties of ionic liquids is crucial in development of gas hydrate technology in industry as these fundamental properties determined the hydrate formation rate. This work measures the density, pH, electrical conductivity, and surface tension of aqueous tetrabutylammonium hydroxide solutions. The concentrations were chosen to cover the common hydrate promotion range of 0.001-10 wt%. The results showed high dependence of the studied properties on the concentration. pH and electrical conductivity were increased with increase of TBAOH concentration conversely to density and surface tension. The amount of CO2 consumed to form the hydrate was measured at a pressure of 35bar and a temperature 274.15. Significant increase of CO2 consumption in the presence of TBAOH solutions was observed. However, as the concentration increased, more CO2 was consumed
Gas Hydrate Equilibrium Measurement of Methane + Carbon Dioxide + Tetrahydrofuran+ Water System at High CO2 Concentrations
No full textAbstractApplication of gas hydrate in separation of carbon dioxide (CO2) form nitrogen in Carbon Capture and Storage (CCS) chain is recently studied by many researchers. Tetrahydrofuran (THF) is suggested as promoter for this process. The same process can be suggested for separation of CO2 from methane (CH4) for gas treatment and sweetening, especially for high CO2 content mixtures such as landfill gas. The first step in development of such process is understanding of the phase boundary of this mixture at different pressure-temperature condition and gas/liquid composition. In this work, gas hydrate phase boundary of CH4, CO2, THF and water at different pressure from 4.5 to 8.1 MPa is experimentally measured. CO2 mole fraction in gas phase is fixed at 0.7 and THF concentration in the liquid phase set at 0.03 mole fraction. Results show that presence of THF in the mixtures shift the phase boundary to the lower pressure / higher temperature condition. This effect is favorable for industrial applications
RAMAN AND INFRARED SPECTRA, CONFORMATIONAL STABILITY, BARRIERS TO INTERNAL ROTATION. AB INITIO CALCULATIONS AND STRUCTURE FOR VINYL SILYL FLUORIDE
No full textAuthor Institution: Department of Chemistry, University of Missouri-Kansas CityThe Raman (3250 to ) and infrared (3250 to ) spectra of the gaseous and solid vinyl silyl fluoride (), have been recorded. From the far infrared spectrum of the gas, the fundamental asymmetric torsions for both the cis and gauche conformers have been observed at 102.34 and , respectively, with each having several excited state transitions falling to lower frequencies. From these transitions, the potential function to internal rotation has been determined with the following values: and , with the gauche conformer thermodynamically preferred by . The cis to gauche, gauche to gauche, and gauche to cis barriers and 702 (8.40 kJ/mol), 588 (7.04 kJ/mol) and (7.42 kJ/mol), respectively. Variable temperature ( to ) studies of the infrared spectra of the sample dissolved in liquid krypton have been carried out. From these data, the enthalpy difference has been determined to be (0.91 kJ/mol). Additionally, ab initio calculations have been carried out utilizing the 6-31G (d) basis sets to obtain the conformational stability, barriers to internal rotation and optimized structural parameters
RAMAN AND INFRARED SPECTRA, CONFORMATIONAL STABILITY, AB INITIO CALCULATIONS AND VIBRATIONAL ASSIGNMENTS FOR ETHYL FLUOROSILANE
No full textAuthor Institution: Department of Chemistry, University of Missouri-Kansas CityThe infrared (3500 to ) spectra of gaseous and solid and the Raman (3500 to ) spectra of the liquid with quantitative depolarization ratios and solid ethyl fluorosilane, , have been recorded. These data indicate that two conformers are present in the fluid states but only one conformer is present in the annealed crystalline state. The mid-infrared spectra of the sample dissolved in liquefied xenon as a function of temperature (-100 to ) have been recorded, Utilizing conformer pairs a 1022 (gauche), 1010 (trans), 719 (gauche), 727 (trans), and 693 (trans) the enthalpy difference has been determined to be kJ/mol) with the gauche conformer the more stable species and the one remaining in the solid. The optimized geometries, conformational stabilities, harmonic force fields, infrared intensities, Raman activities, depolarization ratios, and vibrational frequencies will be reported for both conformers from ab initio calculations. The gauche conformer is predicted to be the more stable rotamer from ab initio calculations in agreement with the experimental results
