873 research outputs found
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
Kinetic Spectrophotometric Determination of Certain Cephalosporins in Pharmaceutical Formulations
A simple, reliable, and sensitive kinetic spectrophotometric method was developed for determination of eight cephalosporin antibiotics, namely, Cefotaxime sodium, Cephapirin sodium, Cephradine dihydrate, Cephalexin monohydrate, Ceftazidime pentahydrate, Cefazoline sodium, Ceftriaxone sodium, and Cefuroxime sodium. The method depends on oxidation of each of studied drugs with alkaline potassium permanganate. The reaction is followed spectrophotometrically by measuring the rate of change of absorbance at 610ânm. The initial rate and fixed time (at 3 minutes) methods are utilized for construction of calibration graphs to determine the concentration of the studied drugs. The calibration graphs are linear in the concentration ranges 5â15âÎŒgâmLâ1 and 5â25âÎŒgâmLâ1 using the initial rate and fixed time methods, respectively. The results are validated statistically and checked through recovery studies. The method has been successfully applied for the determination of the studied cephalosporins in commercial dosage forms. Statistical comparisons of the results with the reference methods show the excellent agreement and indicate no significant difference in accuracy and precision
Carcinome epidermoĂŻde du larynx chez la femme
Le cancer du larynx est assez rare chez la femme. Cependant, il risque dâĂȘtre en recrudescence Ă cause de lâaugmentation du tabagisme fĂ©minin. Peu de travaux se sont consacrĂ©s Ă rechercher les spĂ©cificitĂ©s du cancer du larynx chez la femme.But: Analyser le profil Ă©pidĂ©miologique et clinique des femmes porteuses dâun carcinome Ă©pidermoĂŻde du larynx et dĂ©gager les caractĂ©ristiques thĂ©rapeutiques, Ă©volutives et les facteurs pronostiques chez cette population.MĂ©thodes: Ă©tude rĂ©trospective portant sur 50 femmes prises en charge pour un carcinome Ă©pidermoĂŻde du larynx sur une pĂ©riode de treize ans (1994-2006).RĂ©sultats : LâĂąge moyen de nos patientes Ă©tait de 63,5 ans. Lâintoxication tabagique Ă©tait retrouvĂ©e chez 32,6% des patientes. Chez 30% de nos patientes aucun facteur de risque nâa Ă©tĂ© retrouvĂ©. Les signes cliniques Ă©taient dominĂ©s par la dysphonie suivie de la dyspnĂ©e et la dysphagie. Les tumeurs prenaient naissanceau dĂ©pend de lâĂ©tage glottique dans 55,8% des cas. Nous avons relevĂ©Â que 60,4% des tumeurs Ă©taient vus Ă un stade Ă©voluĂ© T3-T4 et que 95,3% des tumeurs Ă©taient initialement classĂ©es N0. La chirurgie a Ă©tĂ© pratiquĂ©e chez 47,5% des patientes tandis que 16,2% ont reçu une radio-chimiothĂ©rapie. La survie globale cumulĂ©e Ă©tait de 78,8% Ă 3 ans et de 73,5% Ă 5 ans.Conclusion : Lâabsence des facteurs de risque classiques chez un grand nombre de nos patientes laisse supposer le rĂŽle dâautres facteurs Ă©tiopathogĂ©niques dans la genĂšse du cancer du larynx chez la femme. Toute dysphonie chez la femme doit ĂȘtre explorĂ©e mĂȘme en lâabsence de facteurs de risque. La prise en charge et le pronostic semblent superposables Ă celui de lâhomme.Mots clĂ©s : Tumeur â Larynx â Femme â EpidĂ©miologie â 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
Electrochemical kinetics of SEI growth on carbon black, II: Modeling
Mathematical models of capacity fade can reduce the time and cost of
lithium-ion battery development and deployment, and growth of the
solid-electrolyte interphase (SEI) is a major source of capacity fade.
Experiments in Part I reveal nonlinear voltage dependence and strong
charge-discharge asymmetry in SEI growth on carbon black negative electrodes,
which is not captured by previous models. Here, we present a theoretical model
for the electrochemical kinetics of SEI growth coupled to lithium
intercalation, which accurately predicts experimental results with few
adjustable parameters. The key hypothesis is that the initial SEI is a mixed
ion-electron conductor, and its electronic conductivity varies approximately
with the square of the local lithium concentration, consistent with hopping
conduction of electrons along percolating networks. By including a lithium-ion
concentration dependence for the electronic conductivity in the SEI, the bulk
SEI thus modulates the overpotential and exchange current of the electrolyte
reduction reaction. As a result, SEI growth is promoted during lithiation but
suppressed during delithiation. This new insight establishes the fundamental
electrochemistry of SEI growth kinetics. Our model improves upon existing
models by introducing the effects of electrochemical SEI growth and its
dependence on potential, current magnitude, and current direction in predicting
capacity fade.Comment: 1 manuscript, 7 main text figures, 2 supplementary information
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Prise en charge des complications de la chirurgie partielle du larynx
Introduction : Le cancer du larynx est un cancer frĂ©quent occupant la premiĂšre place des cancers des voies aĂ©ro-digestives chez lâhomme en Tunisie. Le tabac est le principal facteur favorisant surtout sâil est associĂ© Ă lâĂ©thylisme chronique. Il sâagit le plus souvent dâun carcinome Ă©pidermoĂŻde plus ou moins diffĂ©renciĂ©. Son pronostic est gĂ©nĂ©ralement bon, en raison de son dĂ©veloppement dans un tube rigide bien limitĂ© et dâun traitement chirurgical actuellement bien codifiĂ©. La chirurgie partielle du cancer du larynx est une chirurgie Ă risque de complications postopĂ©ratoires nĂ©cessitant une prise en charge adĂ©quate.Patients et mĂ©thodes : Notre sĂ©rie comprend 54 patients ayant bĂ©nĂ©ficiĂ© dâune chirurgie partielle du larynx au sein du service de chirurgie carcinologique de lâinstitut Salah Azaiez sur une pĂ©riode de 15 ans (1997-2011).But : PrĂ©senter notre expĂ©rience en matiĂšre de prise en charge des complications de la chirurgie partielle du larynx.RĂ©sultats : La moyenne dâĂąge de nos patients Ă©tait de 54,9 ans avec des extrĂȘmes allant de 33 Ă 69 ans. La prĂ©dominance masculine était nette avec un sex-ratio de 26. La consommation tabagique Ă©tait notĂ©e dans 92,6% des cas et la dysphonie Ă©tait prĂ©sente chez 40 patients porteurs dâune tumeur Ă localisation glottique. Six types dâinterventions ont Ă©tĂ© pratiquĂ©s: cordectomie (9 cas), laryngectomie fronto-latĂ©rale (4 cas), laryngectomie frontale antĂ©rieure reconstructive type Tucker (10 cas), laryngectomie partielle supra-cricoĂŻdienne avec crico-hyoĂŻdopexie (CHP) (4 cas), laryngectomie partielle supra-cricoĂŻdienne avec crico-hyoĂŻdo-Ă©piglottopexie (CHEP) (24 cas) et laryngectomie horizontale supra-glottique (3 cas). Une antibioprophylaxie Ă©tait administrĂ©e chez 79,6% des patients pour une durĂ©e moyenne de 7 jours. Les complications postopĂ©ratoires ont Ă©tĂ© analysĂ©es et discutĂ©es en fonction du type de la chirurgie partielle pratiquĂ©e et du type dâantibiothĂ©rapie utilisĂ©e. Ces complications Ă©taient les suivantes: infection du trachĂ©ostome (20,4%), infection de paroi (5 cas), complications respiratoires (29,6%), emphysĂšme sous cutanĂ© (7,4%), fistule salivaire (1 cas) et pancrĂ©atite aigĂŒe (1 cas).Conclusion : Cette Ă©tude montre dans lâensemble des bons rĂ©sultats tant sur le plan infectieux que respiratoires, justifiant ainsi lâimportance 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
Effet du chrome niacinate sur la tolérance au glucose chez le rat wistar
Le chrome est un oligoĂ©lĂ©ment essentiel Ă lâhomĂ©ostasie du mĂ©tabolisme glucidique qui pourrait Ă©galement ĂȘtre impliquĂ© dans lâĂ©tiologie de lâathĂ©rosclĂ©rose. Trois lots de rats Wistar males (n= 30, ĂągĂ© de 2 mois) traitĂ©s quotidiennement et pendant 28 jours. Les ContrĂŽles ont reçu du sĂ©rum physiologique (1”L/g/j, ip), groupe II a reçu la dexamĂ©thasone (DEX : 0,2 mg/kg/j, ip) et les rats du groupe III ont reçu le mĂȘme rĂ©gime que le groupe II avec une supplĂ©mentation en CrN Ă partir du 7 Ăšme jour de lâexpĂ©rimentation (CrN : 30 mg/kg/j, PO). A la fin de lâexpĂ©rimentation, les rats sont sacrifiĂ©s et les paramĂštres biochimiques sont dosĂ©s. Les rĂ©sultats montrent une augmentation du poids corporel des rats tĂ©moins par apport aux groupes traitĂ©s par la DEX. La supplĂ©mentation en CrN nâa pas corrigĂ© lâĂ©lĂ©vation de la glycĂ©mie et de lâinsulinĂ©mie engendrĂ© par la DEX, de mĂȘme lâajout du CrN nâinflue pas sur la variation des taux de la triglycĂ©ridĂ©mie et de la cholestĂ©rolĂ©mie entrainĂ©s par la DEX. Il est notamment observĂ© que lâaddition du CrN nâa pas dâeffet notable sur la fonction hĂ©patique et la fonction rĂ©nale.Mots-clĂ©s : chrome, diabĂšte, glycĂ©mie, dexamĂ©thasone.Effect of chromium niacinate on glucose tolerance at wistar rat Chromium is an essential trace element in the homeostasis of glucose metabolism could also be involved in the etiology of atherosclerosis. Three groups of male Wistar rats (n= 30, age 2 months) treated daily for 28 days. Controls received saline (1”l/g/day, ip), group II received dexamethasone (DEX: 0, 2 mg/kg/day, ip) and the rats of group III received the same treatment as the group II with supplementation CrN from the 7 day of the experiment (CrN: 30 mg/kg/day, PO). At the end of the experiment, the rats were sacrificed and biochemical parameters were measured. The results show an increase in the body weight of control rats contribution to the DEX treated groups. CrN supplementation did not correct the elevation of blood glucose and insulin caused by DEX. The addition of CrN does not affect the rate of change in triglycerides and cholesterol trained by DEX. It is particularly noted that the addition of CrN has no significant effect on liver and kidney functions.Keywords : chromium, diabetes, glucose, dexamethasone
Perinatal-lethal Gaucher disease presenting as hydrops fetalis
Perinatal-lethal Gaucher disease is very rare and is considered a variant of type 2 Gaucher disease that occurs in the neonatal period. The most distinct features of perinatal-lethal Gaucher disease are non-immune hydrops fetalis. Less common signs of the disease are hepatosplenomegaly, ichthyosis and arthrogryposis. We report a case of Gaucher's disease (type 2) diagnosed in a newborn who presented with Hydrops Fetalis
Diagnostic et prise en charge de lâhyperparathyroĂŻdie primaire
Objectif : LâhyperparathyroĂŻdie primaire (hPTP) est dĂ©finie par la production excessive et inappropriĂ©e de parathormone (PTh). Les formes asymptomatiques et modĂ©rĂ©es sont devenues de plus en plus frĂ©quentes. Le but de ce travail est dâĂ©tudier les caractĂ©ristiques cliniques et paracliniques de lâhPTP, de prĂ©ciser les indications thĂ©rapeutiques et de les discuter en comparant nos rĂ©sultats avec ceux de la littĂ©rature.MatĂ©riel et mĂ©thodes: Il sâagit dâune Ă©tude rĂ©trospective Ă propos de 86 patients colligĂ©s entre Janvier 2005 et DĂ©cembre 2010. Tous les patients ont bĂ©nĂ©ficiĂ© dâun examen ORL et dâun bilan biologique comportant une calcĂ©mie et un dosage de la PTh. Le bilan radiologique comportait une Ă©chographie cervicale, une scintigraphie au MIBI et/ou une IRM cervicale.Tous les patients ont Ă©tĂ© opĂ©rĂ©s sous anesthĂ©sie gĂ©nĂ©rale et ont eu une cervicotomie par approche classique. La surveillance a Ă©tĂ© clinique et biologique avec un recul moyen de 16 mois (4-36 mois).RĂ©sultats : La calcĂ©mie Ă©tait Ă©levĂ©e chez 77 patients (89,5%) et la PTh chez tous les patients. Une Ă©chographie cervicale a Ă©tĂ© rĂ©alisĂ©e chez 79 patients et a montrĂ© une image en faveur dâun adĂ©nome parathyroĂŻdien chez 37 dâentre eux (46,8%). La scintigraphie au MIBI, pratiquĂ©e chez 46 patients, a montrĂ© une hyperfixation dans 31 cas (67,4%). LâIRM aĂ©tĂ© pratiquĂ©e chez 5 patients et a rĂ©vĂ©lĂ© un adĂ©nome dans 3 cas.Lâexploration chirurgicale avec examen extemporanĂ© a rĂ©vĂ©lĂ© un adĂ©nome unique chez 65 patients deux adĂ©nomes chez 12 patients, et une hypertrophie des 4 PTh chez 9 autres. Une exĂ©rĂšse des adĂ©nomes a Ă©tĂ© ainsi rĂ©alisĂ©e chez 77 patients et une parathyroĂŻdectomie subtotale dans 9 cas. en post-opĂ©ratoire, 12 patients (14%) ont prĂ©sentĂ© une hypocalcĂ©mietransitoire. Aucune hypocalcĂ©mie dĂ©finitive ni paralysie rĂ©currentielle nâont Ă©tĂ© notĂ©es. Lâexamen anatomopathologique dĂ©finitif a rĂ©vĂ©lĂ© un adĂ©nome unique, un adĂ©nome double, une hyperplasie et PTh normale respectivement chez 58, 3, 24 et 1 patients. LâĂ©volution Ă long terme a Ă©tĂ© marquĂ©e par lâamĂ©lioration clinique et biologique chez 81 patients (94,2%). Une non-amĂ©lioration clinique et biologique a Ă©tĂ© notĂ©e chez 5 patients. Ils ont Ă©tĂ© rĂ©opĂ©rĂ©s et ont eu une parathyroĂŻdectomie subtotale. Lâanatomopathologie confirmait lâhyperplasie dans tous les cas.Conclusion : Le traitement de lâhPTP symptomatique est chirurgical. Lâapproche classique a fait preuve de son efficacitĂ©. Les progrĂšs rĂ©cents des explorations prĂ©opĂ©ratoires et le dosage peropĂ©ratoire de la PTh ont rendu possible une approche mini-invasive. Des controverses persistent quant Ă la prise en charge de lâhPTP asymptomatique dont lâindicationthĂ©rapeutique doit ĂȘtre bien Ă©tudiĂ©e.Mots-clĂ©s : hyperparathyroĂŻdie primaire, adĂ©nome, glande parathyroĂŻde, parathormone, scintigraphie, parathyroĂŻdectomi
Is dietary zinc protective for type 2 diabetes? Results from the Australian longitudinal study on women's health
Background: Animal studies have shown that zinc intake has protective effects against type 2 diabetes, but few studies have been conducted to examine this relationship in humans. The aim of this study is to investigate if dietary zinc is associated with risk of type 2 diabetes in a longitudinal study of mid-age Australian women. Methods: Data were collected from a cohort of women aged 45-50 years at baseline, participating in the Australian Longitudinal Study on Women's Health. A validated food frequency questionnaire was used to assess dietary intake and other nutrients. Predictors of 6-year incidence of type 2 diabetes were examined using multivariable logistic regression. Results: From 8921 participants, 333 incident cases of type 2 diabetes were identified over 6 years of follow-up. After adjustment for dietary and non-dietary factors, the highest quintile dietary zinc intake had almost half the odds of developing type 2 diabetes (OR = 0.50, 95% C.I. 0.32-0.77) compared with the lowest quintile. Similar findings were observed for the zinc/iron ratio; the highest quintile had half the odds of developing type 2 diabetes (OR = 0.50, 95% C.I 0.30-0.83) after multivariable adjustment of covariates. Conclusions: Higher total dietary zinc intake and high zinc/iron ratio are associated with lower risk of type 2 diabetes in women. This finding is a positive step towards further research to determine if zinc supplementation may reduce the risk of developing type 2 diabetes. © 2013 Vashum et al.; licensee BioMed Central Ltd
Primary thyroid lymphoma: Case report and review of the literature
AbstractPrimary thyroid lymphoma (PTL) is defined as a lymphoma involving only the thyroid gland or both thyroid gland and neck lymph nodes, without contiguous spread or distant metastases from other areas of involvement at diagnosis. Despite its rarity, PTL should be promptly recognized because its management is quite different from the treatment of other neoplasms of the thyroid gland.In the present study, we report a case of PTL treated by surgery and adjuvant chemotherapy. Otherwise, literature review allowed us to define main characteristics of this located lymphoma
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