مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: لخلاصة بالفضة. تمت مطعمة جزيئات ب طعمة م لتحضير مصفوفات هلام – محلول في العمل الحالي ، تم استخدام طريقة ة دراسة معاملات طريقة التحضير من اجل تحديد الظروف المثلى لمصفوف . كما تم ) Dy3+ الديسبروسيوم ( ) Ag الفضة ( - ب طعمة السيليكا الم ة و الفضة النانوية مصفوف تحضير جسيمات الفضة النانوية بطريقة الاختزال الكيميائي. تم استخدام سترات الصوديوم كعامل اختزال. تمت دراسة العديد من المعلمات التي تؤثر على خصائص تحضير الجسيمات . من النتائج التي تم الحصول عليها وجد ان محاليل النانوية ، مثل فترة الاختزال وتركيز ال ر يتطلب فترة اختزال قصيرة وتركيز منخفض. اصغ يمات جس تحضير حجم لوحظ ان فترة وقد xerogels. داخل السيليكا مدمجة تمت دراسة جسيمات الفضة النانوية ال . تم 5 الديسبروسيوم Ag ) - الفضة ( ب المطعمة دقائق وان افضل تركيز لنترات الفضة كان 9 التخفيض الامثل كانت xerogels السيليكا استخدام كلاهما لاحقا لاعداد عينات . (Dy3+ ( كلوريد جسيمات مع على التحليل محلول من عن طريق اذابة الديسبروسيوم هلام بايونات – محلول مصفوفة تطعيم تم Silica xerogels التطعيم المشترك ل . تم Dy3+ مختلفة من بتراكيز الديسبروسيوم جسيمات الفضة النانوية لدراسة تاثير رنين البلازمون السطحي لـ الفضة النانوية لتطبيقات الضوء الابيض. Dy3+ الطيفي لايونات اكدت النتائج التجريبية تكوين جزيئات الفضة النانوية. تم تحديد الحد الادنى لحجم الجسيمات ة اختزال قصيرة وتركيز منخفض. ادى نانومتر مع التوزيع المنتظم عند استخدام فتر 41 البالغ استخدام فترة التخفيض الطويلة والتركيز العالي الى زيادة حجم الجسيمات مع التوزيع غير 144 المنتظم. من نتائج التلالؤ الضوئي ، لوحظت ثلاث قمم انبعاث عند نانومتر 845 و 845 و ) انه تم الحصول على CIE ية ( نانومتر ، واظهرت نتائج مخطط اللون 083 عند الاثارة بمصدر نانومتر. يمكن ان تكون 083 انبعاث ضوئي جيد للضوء الابيض باستخدام طول موجة الاثارة مرشحا واعدا لتطبيقات الضوء الابيض.Ag - Dy3+ ب مطعما السيليكا المشترك xeroge

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خصائص الاغشية الرقيقة للمركب MEH-PPV المشوب بالمعدن كمتحسس غازي == Characterization of metal doped MEH-PPV Thin films for gas sensor

اسم المؤلف: نور مثنى جبار

اسم المشرف: مصطفى محمد علي حسين

الموضوع العام: علوم الفيزياء

السنة: 2022

الموضوع الدقيق: فيزياء الليزر والكهروبصريات

الدرجة: ماجستير

الجامعة: جامعة بغداد

اللغة: الانكليزية

مكان الجامعة: بغداد

الصفحات الاولى:

المستخلص: Abstract In this study, optimized thin films were prepared to measure the gas sensor. Thin films of the nanocomposite were prepared from mixing poly(2- methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene) (MEH-PPV):Ferric Chloride (FeCl3) with different weight ratios and were prepared by spin coating and drop casting methods. Some physical properties of the thin films of pure MEH-PPV nanocomposite and doping FeCl3 were measured at different weight ratios (0.03wt%, 0.06wt%, 0.09wt% and .0.12wt%). When (FTIR) was measured, it was found that a physical reaction occurred and no chemical one between MEH-PPV and FeCl3. As for the measurement of (FESEM), the pure sample MEH-PPV was homogeneous, but when FeCl3 was added in different weight percentages (0.03wt%, 0.06wt%, 0.09 wt% and 0.12wt%) prominent circles were formed indicating the formation of adsorption and it increases as the concentration percentage increases, and the highest adsorption appears in MEH-PPV:FeCl3 (0.06%). Also, by measuring (EDX), The results demonstrate that there are no unwanted elements in the samples. Some elements were found this may due to the contaminator champers which used to test. It also indicates the presence of small peaks of iron (Fe) and chlorine (Cl). Carbon peaks indicate (C) and oxygen (O) to the presence of the chemical elements of MEH-PPV. And when the (UV-Vis) was measured, Determining the band gap for thin films, where it was found that there are two energy gaps, the first region is Q band, and this was an nonsystematic behavior, and the second region is B band, and here the energy gap increases when the ratio of doping increases. It is noted that the MEHPPV polymer has an absorption peak at the wavelength of 490 nm, and when FeCl3 is added, a blue shift is noticed towards short wavelengths at 453 nm. When the Hall effect was measured, it was found that the conductivity and carrier mobility increase when the doping concentration ratio increases. As well as for the measurement of sensors based on MEH-PPV:FeCl3, a Abstract II noticeable response appeared when the sensor was exposed to H2S gas at a concentration of 25 ppm, where the maximum sensitivity at MEHPPV/FeCl3 (0.06%) was 57.36% at an operating temperature of 175°C with a response time (9sec) and recovery time (55.8sec)

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تثبيط تعبير جينات fimH ,fimD ,fimC في بكتريا E. coli الممرضة للمجاري البولية باستعمال جسيمات ثنائي اوكسيد التيتانيوم النانوية المصنعة حيويا من المعززات الحيوية البكتيرية == Inhibition the Expression of fimC, fimD, fimH Genes in Uropathogenic E. coli Using TiO2 Nanoparticles Biosynthesized by Probiotics Bacteria

اسم المؤلف: سوزان عبد الرحيم حسن

اسم المشرف: سوسن ساجد الجبوري | جيهان عبد الستار سلمان

الموضوع العام: علوم الحياة

السنة: 2021

الموضوع الدقيق: الاحياء المجهرية

الدرجة: دكتوراه

الجامعة: الجامعة المستنصرية - كلية العلوم

اللغة: الانكليزية

مكان الجامعة: بغداد

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المستخلص: Summary ►Urinary tract infections (UTIs) are the commonest human bacterial infections and are responsible for substantial morbidity and mortality, resulting in increased healthcare costs. Specialized Escherichia coli strains referred to as Uropathogenic E. coli (UPEC) causes most UTIs. ►Total 120 isolates primarily identified as E.coli; were collected from (December 2018 to February 2019). Out of total collected isolates, 94/120 were included in this study and the contaminated bacteria or weak growth were excluded. The isolated pure colonies were re-identified using some standard morphological tests followed by genetically identification using housekeeping gene (HKG) 16S rDNA. The results confirm that all the isolates were definite as E. coli. ►The UPEC isolates showed their ability of adherence to uroepithelial cells. The aggregation ability of bacterial cells were appeared as dotes on the surface of epithelial cells. ►The antimicrobial susceptibility test (AST) was performed for 50 isolates under study. The highest resistance rate was concerning to Aztreonam; Cefazolin; Ceftazidime and Ceftriaxone (84%), Cefepime (82%), while the minimum resistant was for Imipenem; Ertapenem; Meropenem; Amikacin when it was (2%) beside that none of the isolates was able to resist Tigecycline. According to AST for fifty UPEC isolates; (88%) were multidrug resistance (MDR), while (2%) was extensively drug resistance (XDR) and (10%) were sensitive to all antibiotics thus they were non-drug resistant (NDR). ►All isolates were subjected to detect type1 fimbriae genes (fimA operon) by polymerase chain reaction using specific primers (designed in this study) followed by sequencing the amplified fragment and analyzed using Geneious prime software. The results showed that all the isolates (100%) were positive for fimA, fimI, fimC, fimD, fimG, fimH, while (96%) for fimB, fimF and (82%) for fimE. ►Raw milk samples were collected for probiotics bacteria isolation. All isolates were subjected to the cultural, microscopically, biochemical tests and Vitek2 system. Results indicated that six isolates of Lactococcus spp. Identified as: Lactococcus lactis ssp. lactis, in addition, 14 isolates of Leuconostoc spp. distributed among species as (8) isolates belonged to Leuconostoc mesenteroides ssp. cremoris (3) isolates belonged to Leuconostoc mesenteroides ssp. mesenteroides, (2) isolates identified as Leuconostoc pseudomesenteroides and only one as Leuconostoc citreum. ►All isolated probiotics bacteria were tested for Titanium dioxide (TiO2) nanoparticles production. The results showed that they had the ability to biosynthesize TiO2 NPs, biosynthesized TiO2 NPs were characterized using UVVis Spectroscopy; Atomic Force Microscope (AFM); X-ray Diffraction (XRD); Field Emission Scanning Electron Microscopy (FE-SEM) Energy dispersive Xray spectroscopy (EDX); and Fourier Transform-Infrared Spectroscopy (FTIR). The detected absorption spectrum with a wide-ranging absorption band in UV range and its cut off wavelength was (344-348) nm for all 20 probiotic isolates. ►The smoothness and roughness of all samples of biosynthesized TiO2 NPs was detected by AFM with smoothest sample for L. mesenteroides ssp. cremoris (Leu.4) as 1.137nm. XRD results indicated the formation of nano anatase crystals. ►The Scanning electron microscope images of biosynthesized TiO2 NPs biosynthesized by probiotics bacteria; that were consists of a uniform distribution of spherical shaped nanostructure crystals with a smallest size of (37.48) nm for L. citreum (Leu. 13). ►The EDX analysis of TiO2 NPs existing in medium which confirm that all the samples contained the elements (Ti, O), which again established that the biosynthesized NPs were pure TiO2. ►The determination of functional group of biosynthesized TiO2 NPs studied using FTIR. The main IR absorption peaks of TiO2 biosynthesized by probiotics bacteria were in range at (408- 445) cm-1; these peaks belonged to anatase Titania. ►The biosynthesized TiO2 NPs at concentrations (1000- 0.001) mg/mL were tested for its antibacterial activity against UPEC isolates, thus there was neither bactericidal effect against pathogenic bacteria nor been as minimum inhibitory concentration (MIC). ►There was no effect of temperature, pH and photocatalytic activation on antibacterial activity of biosynthesized TiO2 NPs against clinical UPEC isolates. ►Regardless of no growth inhibition activity showed on culture media after subjecting bacterial UPEC isolates to TiO2 NPs. There was a noticeable inhibitory effect of TiO2 NPs on the attachment ability of bacterial cells without killing them. The highest inhibition was recorded at the higher concentration of biosynthesized TiO2 NPs (1000 g/mL) with inhibition reached 92% and 90.3%, while the lowest inhibition were 52% and 54.8% at 250g/mL against E.coli74 and E.coli23, respectively. ►The effect of biosynthesized TiO2 NPs by probiotics bacteria and commercial TiO2 NPs was studied on the expression of fim genes. There was a subsequent change in the gene expression in term of folding and CT values when the expression of fimH, C, D genes start to decrease by increasing concentration of TiO2 NPs as compared with control and the maximum inhibitions was noticed by using 1000 g/mL concentration of the NPs specially against fimD.

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