Synthesis of green thermo-responsive amphoteric terpolymer functionalized silica nanocomposite derived from waste vegetable oil triglycerides for enhanced oil recovery (EOR)

Despite the high efficiency of polymer flooding as a chemical enhanced oil recovery (CEOR) technique, the low thermal stability and poor salt resistance of widely applied partially hydrolyzed polyacrylamide (HPAM) limited the application of this technique in oil reservoirs at harsh reservoir conditions of high–temperature and high–salinity (HTHS). These inadequacies of HPAM, result in the urge for an environmentally friendly polymer with good viscosifying properties and a substantial effect on mobility ratio at HTHS reservoir conditions. In this research, a high oleic acid waste vegetable oil (WVO) is utilized to synthesize a novel environmentally benign, thermo-responsive amphoteric nanocomposite for EOR applications at HTHS reservoir conditions. A green route transesterification reaction has been utilized to synthesize a novel thermo-sensitive monomer from WVO. The existence of unsaturated fatty acids isolated double bonds and acryloyl functional groups in the synthesized monomer has been confirmed using different characterization methods. The reactive acryloyl double bond in the synthesized monomer has been copolymerized with acrylamide, acrylacyloxyethyltrimethyl ammonium chloride, and 2-acrylamide-2-methylpropane sulfonic acid in presence of dimethylphenylvinylsilane via free radical emulsion polymerization. The synthesized nanocomposite has been characterized by FTIR, 1H NMR, SEM, EDX, TEM, and DLS. The thermal stability of the nanocomposite has been evaluated by TGA and DTA analysis. The results indicated that nanocomposite solution exhibited a pouncing thermo-thickening behaviour and superior viscosifying properties even at an ultra-low polymer concentration of 0.04 wt.% as the temperature increased from 25 to 100 °C, with increasing salinity from 10,000 to 230,000 ppm as well as salt-free solutions. Flooding experiments demonstrated that the oil recovery factor reached 15.4 ± 0.1% using low nanocomposite concentrations of 0.04 wt.%, 22.6 ± 0.3% using nanocomposite concentrations of 0.06 wt.% and 25 ± 0.2% using 0.1 wt.% nanocomposite concentrations evaluated under hostile conditions of 100 °C and salinity of about 230,000 ppm. This research offers a new direction for the synthesis of a novel green, high molecular weight thermo-responsive nanocomposite for EOR application at extremely harsh reservoir conditions via WVO valorization

In vitro propagation of Rosa hybrida L. cv. Al-Taif Rose plant

In this study, a protocol for in vitro propagation of Rosa hybrida L. cv. Al-Taif Rose was established using nodal segments harboring axillary buds as explants. In vitro stages of shoot initiation, multiplication and elongation were performed. Explants were cultured on solid Murashige and Skoog medium (MS) supplemented with different concentrations of benzyl aminopurine (BAP, 1, 2 and 3 mg/l) in combination with 1 mg/l kinetin (Kn). Effect of different concentrations and combinations of indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) on root formation of shoots were studied. The highest percentage of shoot initiation (85%) was observed on MS medium containing 2 mg/l BAP + 1 mg/l Kn, whereas maximum average number of multiplied shoots (2.7) was produced on MS medium with 3 mg/l BAP + 1 mg/l Kn. Highest average number of elongated shoots (26.7) was noticed on MS medium containing 1 mg/l BAP and 1 mg/l Kn. For rooting, highest percentage (66.7%) of rooted shoots was obtained on MS medium supplemented with 2 mg/l IBA. Plantlets with 4 to 5 roots of 3 to 5 cm length were successfully transferred to pots containing sterile peat moss for acclimatization.Keywords: Rosa hybrid L. cv. Al-Taif Rose, axillary bud explants, in vitro propagation, multiplication, acclimatizatio

Synthesis and characterization of a novel amphoteric terpolymer nanocomposite for enhanced oil recovery applications

Water-soluble polymers are highly applied to increase the recovery from oil reservoirs. The application of these polymers in enhanced oil recovery (EOR) has some limitations regarding chemical, thermal and mechanical degradation at harsh reservoir condition. In this research, a novel stable terpolymer has been synthesised by preparing and grafting vinylbenzyl starch with poly (acrylamide/ acrylic acid/ acrylacyloxyethyltrimethyl ammonium chloride) in the presence of silica nanoparticles via free radical emulsion polymerization. Different stability investigations have been applied for the synthesised polymer including temperature, salinity and shear stability analyses at harsh conditions. The chemical structure of the novel polymer has been characterized using numerous methods including proton nuclear magnetic resonance (1H NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy and high-resolution transmission electron microscope (TEM). Thermal properties have been evaluated by thermal gravimetric analysis (TGA). The rheological properties have been studied at harsh reservoir conditions in terms of formation water salinity, temperature, and shear rate. The results have shown that the introduction of vinylbenzyl starch has significantly enhanced the thermal and chemical stability of the prepared polymer. Moreover, flooding experiments conducted on sandstone core have shown that the synthesised terpolymer can enhance the oil recovery up to 43% at polymer concentration of 3 g/L

Green Corrosion Inhibitors, Past, Present, and Future

Green corrosion inhibitors are of interest because there has been an increase in environmental awareness and a change in regulations that restrict regular corrosion inhibitors due to their toxicity. Natural products are a good source of green corrosion inhibitors, where most of their extracts containing the necessary elements such as O, C, N, and S, which are active in organic compounds, assist in adsorption of these compounds on metals or alloys to form a film that protects the surface and hinders corrosion. Numerous natural products and their application in different processes, especially in steel reinforcement embedded in concrete, are discussed. Development of green chemistry and green chemical technologies offers novel synthetic methods for ionic liquids, which are considered as new corrosion green inhibitors, and their mechanism of adsorption, how these green inhibitors act in different media, and their protective role for different metals and alloys are discussed. Finally, industrial applications of vapor-phase inhibitors and their mechanisms are presented

Prise en charge des complications de la chirurgie partielle du larynx

Introduction : Le cancer du larynx est un cancer fréquent occupant la première place des cancers des voies aéro-digestives chez l’homme en Tunisie. Le tabac est le principal facteur favorisant surtout s’il est associé à l’éthylisme chronique. Il s’agit le plus souvent d’un carcinome épidermoïde plus ou moins différencié. Son pronostic est généralement bon, en raison de son développement dans un tube rigide bien limité et d’un traitement chirurgical actuellement bien codifié. La chirurgie partielle du cancer du larynx est une chirurgie à risque de complications postopératoires nécessitant une prise en charge adéquate.Patients et méthodes : Notre série comprend 54 patients ayant bénéficié d’une chirurgie partielle du larynx au sein du service de chirurgie carcinologique de l’institut Salah Azaiez sur une période de 15 ans (1997-2011).But : Présenter notre expérience en matière de prise en charge des complications de la chirurgie partielle du larynx.Résultats : La moyenne d’âge de nos patients était de 54,9 ans avec des extrêmes allant de 33 à 69 ans. La prédominance masculine était nette avec un sex-ratio de 26. La consommation tabagique était notée dans 92,6% des cas et la dysphonie était présente chez 40 patients porteurs d’une tumeur à localisation glottique. Six types d’interventions ont été pratiqués: cordectomie (9 cas), laryngectomie fronto-latérale (4 cas), laryngectomie frontale antérieure reconstructive type Tucker (10 cas), laryngectomie partielle supra-cricoïdienne avec crico-hyoïdopexie (CHP) (4 cas), laryngectomie partielle supra-cricoïdienne avec crico-hyoïdo-épiglottopexie (CHEP) (24 cas) et laryngectomie horizontale supra-glottique (3 cas). Une antibioprophylaxie était administrée chez 79,6% des patients pour une durée moyenne de 7 jours. Les complications postopératoires ont été analysées et discutées en fonction du type de la chirurgie partielle pratiquée et du type d’antibiothérapie utilisée. Ces complications étaient les suivantes: infection du trachéostome (20,4%), infection de paroi (5 cas), complications respiratoires (29,6%), emphysème sous cutané (7,4%), fistule salivaire (1 cas) et pancréatite aigüe (1 cas).Conclusion : Cette étude montre dans l’ensemble des bons résultats tant sur le plan infectieux que respiratoires, justifiant ainsi l’importance de la prise en charge des complications de la chirurgie partielle du cancer du larynx.Introduction : Laryngeal cancer is a common cancer occurring mainly in men. Smoking is the main risk factor especially if associated with chronic alcoholism. Squamous cell carcinoma is the most common histologic type. Prognosis is generally good, due to the development of the tumor in a very limited rigid tube and to a well-codified surgical treatment. Partial surgery of laryngeal cancer is characterized by postoperative complications requiring an adequate management.Methods : Our series includes 54 cases of laryngeal cancer treated with partial laryngectomy in the ENT department of Salah Azaiez Institute over a period of 15 years from 1997 to 2011.Objective : To present our experience in the management of partial laryngeal surgery complications.Results : Average age of our patients was 54.9 years ranging from 33 to 69 years. Male predominance was marked with a sex ratio of 26. Tobacco abuse was found in 92.6%. Dysphonia was the most common symptom found in 40 patients with glottic cancer. Six varieties of partial laryngectomy were performed: cordectomy (9 cases), fronto-lateral laryngectomy (4 cases), fronto-anterior reconstructive laryngectomy (10 cases), partial supra-cricoid laryngectomy with CHP (4 cases), partial supra-cricoid laryngectomy with CHEP (24 cases) and supra glottic horizontal laryngectomy (3 cases). 79.6 % of our patients received prophylactic antibiotics for an average of 7 days. Postoperative complications were analyzed and discussed in terms of the type of surgery performed and the antibiotic used. Complications observed were: infection of the tracheostoma (20.4%), parietal infection (5 cases), respiratory complications (29.6%), subcutaneous emphysema (7.4%), salivary fistula (1 case) and acute pancreatitis (1 case).Conclusion : This study shows overall good results for partial laryngeal cancer surgery with minimal post-operative complications and oncologic failure justifying the importance of an early management of these complications

Carcinome epidermoïde du larynx chez la femme

Le cancer du larynx est assez rare chez la femme. Cependant, il risque d’être en recrudescence à cause de l’augmentation du tabagisme féminin. Peu de travaux se sont consacrés à rechercher les spécificités du cancer du larynx chez la femme.But: Analyser le profil épidémiologique et clinique des femmes porteuses d’un carcinome épidermoïde du larynx et dégager les caractéristiques thérapeutiques, évolutives et les facteurs pronostiques chez cette population.Méthodes: étude rétrospective portant sur 50 femmes prises en charge pour un carcinome épidermoïde du larynx sur une période de treize ans (1994-2006).Résultats : L’âge moyen de nos patientes était de 63,5 ans. L’intoxication tabagique était retrouvée chez 32,6% des patientes. Chez 30% de nos patientes aucun facteur de risque n’a été retrouvé. Les signes cliniques étaient dominés par la dysphonie suivie de la dyspnée et la dysphagie. Les tumeurs prenaient naissanceau dépend de l’étage glottique dans 55,8% des cas. Nous avons relevé que 60,4% des tumeurs étaient vus à un stade évolué T3-T4 et que 95,3% des tumeurs étaient initialement classées N0. La chirurgie a été pratiquée chez 47,5% des patientes tandis que 16,2% ont reçu une radio-chimiothérapie. La survie globale cumulée était de 78,8% à 3 ans et de 73,5% à 5 ans.Conclusion : L’absence des facteurs de risque classiques chez un grand nombre de nos patientes laisse supposer le rôle d’autres facteurs étiopathogéniques dans la genèse du cancer du larynx chez la femme. Toute dysphonie chez la femme doit être explorée même en l’absence de facteurs de risque. La prise en charge et le pronostic semblent superposables à celui de l’homme.Mots clés : Tumeur – Larynx – Femme – Epidémiologie – TabagismeLaryngeal cancer is quite uncommun in women. However, it may be on the rise due to the increase in smoking among women. Few studies have been devoted to find the specifics of laryngeal cancer in women.Purpose: to analyze the epidemiological and clinical profile of squamous cell carcinoma of the larynx in women, and to identify therapeutic characteristics and prognostic factors in this population.Methods: retrospective study of 50 womens treated for squamous cell carcinoma of the larynx over a period of thirteen years (1994- 2006).Results: The mean age of our patients was 63.5 years. The tobacco abuse was found in 32.6% of patients. In 30% of our patients no risk factors were found. Clinical signs were dominated by dysphonia followed by dyspnea and dysphagia. Primary tumor was localized in glottis in 55.8% of cases. We found that 60.4% of tumors were seen at an advanced stage T3-T4 and 95.3% of the tumors were initially classified N0. The surgery was performed in 47.5% of patients, while 16.2% received chemoradiotherapy. The cumulative overall survival was 78.8% at 3 years and 73.5% at 5 years.Conclusion: The absence of conventional risk factors in a large number of our patients suggests the role of other etiologic factors in the genesis of laryngeal cancer in women. Every dysphonia in women should be explored even in the absence of risk factors. The  management and prognosis seem congruent with that of man.Key words: Tumor-larynx-women-epidemiology-smokin

Serum Interleukin-4 and Total Immunoglobulin E in Nonatopic Alopecia Areata Patients and HLA-DRB1 Typing

Background. Interleukin-4 (IL-4), a Th2 cytokine, can stimulate immunoglobulin E (IgE) transcription. No previous studies evaluated the genetic mechanisms in nonatopic AA patients with elevated serum IgE. Objective. To compare serum IL-4 and total IgE levels between Egyptian nonatopic AA patients and healthy subjects and to investigate a possible relation to HLA-DRB1 alleles. Results. Serum IL-4 and total IgE were measured by ELISA in 40 controls and 54 nonatopic AA patients. Patients' HLA-DRB1 typing by sequence specific oligonucleotide probe technique was compared to normal Egyptian population. We found significantly elevated serum IL-4 and total IgE in AA patients (particularly alopecia universalis, AU, and chronic patients) (P < .01). HLA-DRB1*11 is a general susceptibility/chronicity allele. DRB1*13 is a protective allele. DRB1*01 and DRB1*07 are linked to chronicity. Localized AA showed decreased DRB1*03 and DRB1*07. Extensive forms showed increased DRB1*08 and decreased DRB1*04. Elevated IL4 and IgE were observed in patients with DRB1*07 and DRB1*11 not DRB1*04. Conclusion. Serum IL-4 and IgE are elevated in nonatopic AA patients, particularly AU and chronic disease. Relevant susceptibility, chronicity, and severity HLADRB1 alleles may have a role in determining type, magnitude, and duration of immune response in AA favouring increased IL4 and IgE