Appraisal of synthetic cationic Gemini surfactants as highly efficient inhibitors for carbon steel in the acidization of oil and gas wells: an experimental and computational approach.

New cationic Gemini surfactant (CGS) molecules were synthesized and investigated as anticorrosive materials for carbon steel (CS) in 1 M HCl solution by chemical, electrochemical and theoretical studies such as DFT and MDS approaches. The anticorrosion efficacy increased with the increase in the CGS concentration. It reached 95.66% at 5 × 10-3 M of the CGS molecule using PDP measurements. PDP studies confirm that the CGS molecule acts as a mixed inhibitor. The EIS outcomes were explained by an equivalent circuit in which a constant phase element (CPE) rather than a double-layer capacitance (C dl) was exploited to donate a more precise fit of the experimental outcomes. The CGS molecule follows the Langmuir isotherm as it is chemically adsorbed onto the surface of CS. To explore the kinetic and adsorption mechanisms, the thermodynamic characteristics of the activation and adsorption processes were assessed under the impact of temperature. Frontier molecular orbitals (FMOs) were achieved by the density functional theory (DFT) method. The study of interatomic interactions at the [CS (Fe(110))]/CGS level was discussed using molecular dynamics (MD) simulation.

Adsorption and Corrosion Performance of New Cationic Gemini Surfactants Derivatives of Fatty Amido Ethyl Aminium Chloride with Ester Spacer for Mild Steel in Acidic Solutions.

Three new cationic gemini surfactants with ester spacer type 2-2'-(ethane-1,2-diyl bis(oxy)) bis(N-(2-alkanamidoethyl)-N,N-dimethyl-2-oxoethan-1-aminium)) dichloride) (CGSES12, CGSES14 and CGSES16), based on N,N-dimethyl fatty amido ethylamine, were produced. These gemini quaternary ammonium salts were synthesized using a three-step reaction method, starting from th/e condensation of the fatty acid chloride (RCOCl) of various hydrophobic chain lengths (R, C11H23, C13H27, C15H31) with N,N-dimethyl ethylene diamine, followed by the quaternization of the tertiary amino group formed with the spacer of the ester group formed in the second step. The chemical configuration of the surfactants was established by FT-IR, 1HNMR, 13CNMR and Mass spectroscopies. The inhibition performance of three surfactants was studied by weight loss and electrochemical measurements. The results show that CGSES12, CGSES14 and CGSES16 behave as effective inhibitors and surface agents. The maximum efficiency was higher than 94% at 2.5 mM, and the inhibition order was CGSES16 > CGSES14 > CGSES12. This was due to the increment in hydrophobicity of the gemini surfactants. Their adsorption on a mild steel surface followed the Langmuir isotherm. CGSES12, CGSES14 and CGSES16 can be considered mixed-type inhibitors. The presence of CGSES12, CGSES14 and CGSES16 increased charge transfer resistance and decreased the corrosion rate. The adsorption focused on heteroatoms and the surface properties of cationic gemini surfactants.

Enhancement of A Cationic Surfactant by Capping Nanoparticles: Synthesis, Characterization and Multiple Applications.

There is scarce information on cationic surfactants' biocidal and corrosion inhbibition effects on Slime-Forming Bacteria (SFB) isolated from oil field formation water. Therefore, this work focused on the the synthesis of a cationic surfactant (CS) to increase its features by capping different metal nanoparticles (zinc, ZnNPs-C-CS; manganese, MnNPs-C-CS and tin, SnNPs-C-CS) and used them as biocides and corrosion inhibitors. The cationic surfactant was synthesized and characterized by Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. Afterwards, different nanoparticles were synthesized, characterized, and exploited to cap by the CS. The CS and the different nanoparticles capped by the CS were tested for their antimicrobial susceptibility against standard bacterial and yeast strains. The synthesized compounds were further evaluated as anti-biofilms agents against positively-developed bacterial biofilms. Moreover, the CS and the ZnNPs-C-CS, MnNPs-C-CS, and SnNPs-C-CS were assessed as potential biocides against SFB, particularly Pseudomonas sp. (isolated from contaminated formation water), and as corrosion inhibitors against cultivated salinity. The results revealed the great effect of the different CS-capped NPs as broad-spectrum antimicrobial and anti-biofilm agents at lower Minimum Inhibitory Concentrations (MICs), Minimum Bactericidal Concentrations (MBCs), Minimum Fungicidal Concentrations (MFCs) and Minimum Biofilm Inhibitory Concentrations (MBICs), and the activities were reported in order of SnNPs-C-CS > MnNPs-C-CS > ZnNPs-C-CS > CS. Furthermore, the ZnNPs-C-CS, MnNPs-C-CS, and SnNPs-C-CS demonstrated biocidal and corrosion inhibition effects against Pseudomonas sp. at a salinity of 3.5% NaCl, with metal corrosion inhibition efficiencies of 88.6, 94.0 and 96.9%, in comparison to a CS efficiency of 85.7%. In conclusion, the present work provides a newly synthesized cationic surfactant and has enhanced its antimicrobial and its metal corrosion inhibition effects by capping different nanoparticles, and it has been successfully applied against slime-forming bacteria at a salinity of 3.5% NaCl.

4,4'-(((1E,5E)-pentane-1,5-diylidene)bis(azanylylidene))bis(1-dodecylpyridin-1-ium) bromide as a novel corrosion inhibitor in an acidic solution (part I).

The metal corrosion inhibition efficiency of a novel synthesized cationic gemini surfactant (SCGS), namely, 4,4'-(((1E,5E)-pentane-1,5-diylidene)bis(azanylylidene))bis (1-dodecylpyridin-1-ium) bromide, was studied in acidic medium by three techniques. The achieved results displayed the inhibition efficiency of the metal corrosion that was elevated by increasing both the SCGS's concentration and the applied temperature values. Furthermore, it was noticed that the charge transfer resistance value was elevated; however, the constant phase element was decreased with increasing the SCGS concentrations. The SCGS regards an excellent and mixed-type corrosion inhibitor. The adsorption of SCGS has agreed the Langmuir's adsorption isotherm and was related to physisorption and chemisorption.

Multiple Applications of a Novel Cationic Gemini Surfactant: Anti-Microbial, Anti-Biofilm, Biocide, Salinity Corrosion Inhibitor, and Biofilm Dispersion (Part II).

The Egyptian petroleum industries are incurring severe problems with corrosion, particularly corrosion that is induced by sulfidogenic microbial activities in harsh salinity environments despite extensively using biocides and metal corrosion inhibitors. Therefore, in this study, a synthesized cationic gemini surfactant (SCGS) was tested as a broad-spectrum antimicrobial, anti-bacterial, anti-candida, anti-fungal, anti-biofilm (anti-adhesive), and bio-dispersion agent. The SCGS was evaluated as a biocide against environmental sulfidogenic-bacteria and as a corrosion inhibitor for a high salinity cultivated medium. The SCGS displayed wide spectrum antimicrobial activity with minimum bactericidal/fungicidal inhibitory concentrations. The SCGS demonstrated anti-bacterial, anti-biofilm, and bio-dispersion activity. The SCGS exhibited bactericidal activity against environmental sulfidogenic bacteria and the highest corrosion inhibition efficiency of 93.8% at 5 mM. Additionally, the SCGS demonstrated bio-dispersion activity against the environmental sulfidogenic bacteria at 5.49% salinity. In conclusion, this study provides a novel synthesized cationic surfactant with many applications in the oil and gas industry: as broad-spectrum antimicrobial and anti-biofilm agents, corrosion inhibition for high salinity, biocides for environmentally sulfidogenic bacteria, and as bio-dispersion agents.

Papillary thyroid carcinoma in cervical lymph nodes with vanished thyroid gland after ablation of Graves' disease by radioactive iodine.

Primary thyroid carcinoma after thyroid ablation by radioactive iodine is rare. We present a very rare condition of lateral apparent papillary thyroid carcinoma eight years after receiving radioactive iodine for thyrotoxicosis, which led to complete anatomical and functional involution of the thyroid gland.

Donor related risk factors on the outcome of living donor liver transplantation

Background & objective: Liver transplantation is an established, effective treatment for acute and chronic end stage liver disease. Donors risk factors should be studied in order not to compromise the procedure of transplantation or to lose candidates for transplantation, the study aims to evaluate the effect of variable donor risk factors on the outcome of Living donor liver Transplantation regarding the morbidity and mortaly .Methods: the current study conducted on 48 patients who underwent living donor liver transplantation for End stage liver disease caused by chronic HCV. Morbidity and mortality were assessed at three and twelve months. Obtained data were studied in correlation with various donor related risk factors, a score designed to collect these risk factors, correlate them with recipient mortality, and graft rejection.Results: high rates of graft rejection and recipient mortality was significantly related to older donor age, donor obesity, donorrecipient gender mismatch, hepatic steatosis, and donor graft recipient weight ratio (GRWR) ≤ 0.8. The designed donor risk score of ≥ 7 was expectedly to associate with poor outcome & recipient mortality.Conclusion: The present study suggested that donor risk score can be a strong predictor of donor related risk factors and its effect on the outcome of Living Donor Liver Transplantation in patients espicially with hepatitis C genotype 4

The biocidal effect of a novel synthesized gemini surfactant on environmental sulfidogenic bacteria: planktonic cells and biofilms.

A cationic gemini surfactant was synthesized and characterized. The surfactant was successfully applied as a biocide against environmental sulfidogenic bacteria in the bulk phase (planktonic) and on the surface (biofilm). The activity of the synthesized surfactant was discussed based on the redox potential and the sulfide productivity in the bulk phase. The cultivated biofilm structure analysis and corrosion rate were estimated on the metal surface. The lowest metal corrosion rate was recognized at a concentration of 1mM with a metal corrosion inhibition efficiency of 95%. The synthesized gemini surfactant prevented the biofilm formation at a concentration of 0.1mM. The synthesized gemini surfactant displayed a broad spectrum antibacterial activity against Gram-positive and Gram-negative bacteria.

Role of computed tomography angiography in the diagnosis of vascular stenosis in head and neck microvascular free flap reconstruction.

The aim of this study was to evaluate the role of computed tomography angiography (CTA) in the diagnosis of vascular stenosis at the vascular pedicle of head and neck microvascular free flaps. A prospective study was done of 65 consecutive patients (49 male, 16 female; mean age 55 years) who had undergone head and neck microvascular free flap reconstruction. All patients underwent 64-slice CTA of the carotid artery. Post-processing with volume rendering reconstruction of CTA images was done. There was excellent inter-observer agreement (weighted kappa=0.82, 95% confidence interval (CI) 0.74-0.93) in grading of the degree of vascular stenosis. The true sensitivity of CTA for diagnosis of stenosis of the vascular pedicle to the flap was 63% (95% CI 63-100%). Patients with failed flaps showed complete occlusion (n=2) on CTA and underwent a replacement flap procedure. Patients with failing flaps showed severe stenosis (n=6) of the vascular pedicle on CTA and underwent revision surgery. There was no change in the degree of stenosis on follow-up CTA for patients with moderate stenosis (n=9). CTA is a reliable, non-invasive, high-quality imaging tool for the diagnosis and grading of vascular stenosis of the vascular pedicle of head and neck microvascular free flaps.

Amalgamation of procalcitonin, C-reactive protein, and sequential organ failure scoring system in predicting sepsis survival.

BACKGROUND: The clinical value of inflammatory biomarkers is still questionable. AIM OF THE WORK: The aim of this study is to compare the clinical informative value of procalcitonin (PCT) and C-reactive protein (CRP) plasma concentration in the early detection of sepsis, as well as relating these biomarkers to other scoring systems. PATIENTS AND METHODS: A total of 138 patients were enrolled in our study. All were subjected to PCT, CRP, and sequential organ failure assessment (SOFA) scores daily for 7 days (starting from admission day). Blood samples were collected before starting antibiotics, with 28 days follow-up and patients were assigned to three groups: Group I: SOFA 2-7, Group II: SOFA 8-10, and Group III: SOFA ≥11. RESULTS: Underlying clinical diagnosis revealed pneumonia in 72 patients, urinary tract infections in eight, bloodstream infection in four, and other infections in 23, while infection could not be traced in 25 patients. The mean PCT was 3 ng/ml (95% confidence interval [CI]: 1-4), 12 ng/ml (95% CI: 9.1-14), and 19 ng/ml (95% CI: 16.3-22.3) in Groups I, II, and III, respectively, with a statistically significant difference in the mean PCT level among the three groups (P < 0.0001). On the other hand, CRP mean level did not significantly differentiate between the groups (147.1 mg/L in Group II, which was even higher than the level of Group III, 138.4 mg/L). CONCLUSION: PCT seems to do better than CRP in predicting the SOFA groups, giving its patronage display over a wide spectrum of insults.

Bivariate versus multivariate smart spectrophotometric calibration methods for the simultaneous determination of a quaternary mixture of mosapride, pantoprazole and their degradation products.

The ability of bivariate and multivariate spectrophotometric methods was demonstrated in the resolution of a quaternary mixture of mosapride, pantoprazole and their degradation products. The bivariate calibrations include bivariate spectrophotometric method (BSM) and H-point standard addition method (HPSAM), which were able to determine the two drugs, simultaneously, but not in the presence of their degradation products, the results showed that simultaneous determinations could be performed in the concentration ranges of 5.0-50.0 microg/ml for mosapride and 10.0-40.0 microg/ml for pantoprazole by bivariate spectrophotometric method and in the concentration ranges of 5.0-45.0 microg/ml for both drugs by H-point standard addition method. Moreover, the applied multivariate calibration methods were able for the determination of mosapride, pantoprazole and their degradation products using concentration residuals augmented classical least squares (CRACLS) and partial least squares (PLS). The proposed multivariate methods were applied to 17 synthetic samples in the concentration ranges of 3.0-12.0 microg/ml mosapride, 8.0-32.0 microg/ml pantoprazole, 1.5-6.0 microg/ml mosapride degradation products and 2.0-8.0 microg/ml pantoprazole degradation products. The proposed bivariate and multivariate calibration methods were successfully applied to the determination of mosapride and pantoprazole in their pharmaceutical preparations.