The impact of environmentally friendly supramolecular coordination polymers as carbon steel corrosion inhibitors in HCl solution: synthesis and characterization.

Two 3D-supramolecular coordination polymers (SCP1 & SCP2) have been synthesized and characterized by physicochemical and spectroscopic methods. In a solution of 1.0 M HCl, SCPs were used to prevent corrosion of carbon steel (CS). The inhibition productivity (%η) rises as the synthetic inhibitor dose rises, and the opposite is true as the temperature rises. The study was carried out using chemical (mass loss, ML) and electrochemical ( potentiodynamic polarization, PDP and electrochemical impedance microscopy, EIS) techniques, which showed %η reached to 93.1% and 92.5% for SCP1 & SCP2, respectively at 21 × 10-6 M, 25 °C. For the polarization results, SCPs behave as mixed-type inhibitors. With increasing doses of SCPs, the charge transfer resistance grew and the double layer's capacitance lowered. The creation of a monolayer on the surface of CS was demonstrated by the finding that the adsorption of SCPs on its surface followed the Henry adsorption isotherm. The parameters of thermodynamics were computed and explained. The physical adsorption of SCPs on the surface of CS is shown by the lowering values of free energy (∆Goads < - 20 kJ mol-1) and increasing the activation energy (E*a) values in presence of SCP1 & SCP2 than in their absence. Atomic force microscope (AFM) and scanning electron microscopy (SEM) demonstrated the development of a protective thin film of SCPs precipitated on the surface of CS. There is a strong matching between results obtained from experimental and theoretical studies. Results from each approach that was used were consistent.

Insights into the use of two novel supramolecular compounds as corrosion inhibitors for stainless steel in a chloride environment: experimental as well as theoretical investigation.

Novel supramolecular (SCPs) compounds such as: {[Ni (EIN)4(NCS)2]}, SCP1 and {[Co (EIN)4 (NCS)2]}, SCP2 have been studied using weight loss (WL) and electrochemical tests on the corrosion performance of stainless steel 304 (SS304) in 1.0 M hydrochloric acid (HCl) solution. The experimental results revealed that inhibition efficacy (η%) rises with increasing concentrations of SCPs and reached 92.3% and 89.6% at 16 × 10-6 M, 25 °C, from the WL method for SCP1 and SCP2, respectively. However, by raising the temperature, η% was reduced. Polarization measurements (PDP) showed that the SCPs molecules represent a mixed-type. The SCPs were adsorbed on a SS304 surface physically, and the Langmuir adsorption isotherm was found to govern the adsorption process. The determination of thermodynamic parameters was carried out at various temperatures. Quantum chemical calculations were calculated to prove the adsorption process of SCP components, using the molecular dynamics (MD) simulations and electron density map. The inhibition performance of SCPs for SS304 dissolution in an acidic medium was proved to be excellent through FT-IR and AFM analysis. The results obtained from all measurements exhibit a high level of agreement with each other.

Novel porphyrin derivatives as corrosion inhibitors for stainless steel 304 in acidic environment: synthesis, electrochemical and quantum calculation studies.

A Novel 5,10,15,20-tetra (thiophen-2-yl) porphyrin (P1) and 5,10,15,20-tetrakis (5-Bromothiophen-2-yl) porphyrin (P2) were successfully synthesized, and their chemical structures were proved based on its correct elemental analysis and spectral data (IR and 1H-NMR). These compounds were examined as corrosion inhibitors for stainless steel 304 (SS304) in 2 M HCl utilizing mass reduction (MR) and electrochemical tests at inhibitor concentration (1 × 10-6-21 × 10-6 M). The protection efficiency (IE %) was effectively enhanced with improving the concentration of investigated compounds and reached 92.5%, 88.5% at 21 × 10-6 M for P1 & P2, respectively and decreases with raising the temperature. Langmuir's isotherm was constrained as the best fitted isotherm depicts the physical-chemical adsorption capabilities of P1 & P2 on SS304 surface with change in ΔGoads = 22.5 kJ mol-1. According to the PDP data reported, P1 and P2 work as mixed find inhibitors to suppress both cathodic and anodic processes. Porphyrin derivatives (P1 & P2) are included on the surface of SS304, according to surface morphology techniques SEM/EDX and AFM. Quantum calculations (DFT) and Monte Carlo simulation (MC) showed the impact of the chemical structure of porphyrin derivatives on their IE %.

Nano-metal-organic frameworks as corrosion inhibitors for strengthening anti-corrosion behavior of carbon steel in a sulfuric acid environment: from synthesis to applications.

In order to demonstrate the effect of Nano-metal organic frameworks, [Cu2(CN)4(Ph3Sn) (Pyz2-caH)2] (NMOF1) and [∞3[Cu(CN)2(Me3Sn)(Pyz)]] (NMOF2) as corrosion inhibitors for C-steel in 0.5 M sulfuric acid solutions, the following methods were utilized: mass reduction (MR), potentiodynamic polarization (PDP), and AC electrochemical impedance (EIS). The results of the experiments showed that by increasing the dose of these compounds, the inhibition efficacy (η%) of C-steel corrosion increased and reached 74.4-90% for NMOF2 and NMOF1 at a dose of 25 × 10-6 M, respectively. On the other hand, the η% decreased as the temperature range rose. Parameters for activation and adsorption were determined and discussed. Both NMOF2 and NMOF1 were physically adsorbed on the surface of C-steel and conformed to the Langmuir adsorption isotherm model. The PDP studies revealed that these compounds functioned as mixed type inhibitors, i.e. affecting both metal dissolution and hydrogen evolution reactions. Attenuated Total Reflection Infra-Red (ATR-IR) analysis was carried out to determine the morphology of the inhibited C-steel surface. There is good agreement between the findings of EIS, PDP and MR.

Synthesis and characterization of novel acrylamide derivatives and their use as corrosion inhibitors for carbon steel in hydrochloric acid solution.

Two new acrylamide derivatives were prepared namely: "N-(bis(2-hydroxyethyl) carbamothioyl) acrylamide (BHCA) and N-((2-hydroxyethyl) carbamothioyl) acrylamide( HCA) and their chemical structures were analyzed and confirmed using IR and 1H NMR". These chemicals were investigated as corrosion inhibitors for carbon steel (CS) in 1 M HCl medium using chemical method (mass  loss, ML), and electrochemical techniques including potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). The results showed that the acrylamide derivatives work well as corrosion inhibitors, with inhibition efficacy (%IE) reaching 94.91-95.28% at 60 ppm for BHCA and HCA, respectively. Their inhibition depends mainly on their concentration and temperature of the solution. According to the PDP files, these derivatives function as mixed-type inhibitors that physically adsorb on the CS surface in accordance with the Langmuir adsorption isotherm, creating a thin coating that shields the CS surface from corrosive fluids. The charge transfer resistance (Rct) increased and the double layer capacitance (Cdl) decreased as a result of the adsorption of the used derivatives. Calculated and described were the thermodynamic parameters for activation and adsorption. Quantum chemistry computations and Monte Carlo simulations were examined and discussed for these derivatives under investigation. Surface analysis was checked using atomic force microscope (AFM). Validity of the obtained data was demonstrated by the confirmation of these several independent procedures.

Change of site of intra-articular injection of hypertonic dextrose resulted in different effects of treatment.

Most minimally invasive treatments for dysfunction of the temporomandibular joint (TMJ) are empirical, and aimed at the painful trigger points with the purpose of preventing muscular spasm and restoring normal function. In this prospective study I investigated whether the choice of site of injection of hypertonic dextrose affected the benefits of treatment of internal derangement and pain. I studied 72 patients with pain and clicking as a result of dysfunction of the TMJ. Patients were divided into four groups with four separate sites for intra-articular injection. Dextrose was injected into the superior joint space, inferior joint space, retrodiscal tissue, and anterior capsule injection. Results showed that the retrodiscal site was the most effective for reducing clicking and subsequently improving derangement, while the inferior joint space was the best site for the relief of pain, and the extracapsular site should be used in cases of hypermobility. In conclusion, the injection site should be selected according to the symptoms being treated, and could be used as an adjunct to other sites to improve outcome.

Progressive stridor: could it be a congenital cystic lung disease?

UNLABELLED: Bronchogenic cyst of the mediastinum, a cause of stridor early in life, is the result of abnormal budding of the ventral segment of the primitive foregut. Bronchogenic cysts are often asymptomatic in older children and adults. However, symptomatic cases usually manifest early in life with cough, stridor or wheezing due to airway compression. We report a female infant aged 4.5 months with a normal full-term pregnancy, who developed respiratory distress with stridor. This stridor was preceded by a history of slowly progressive noisy breathing. Physical examination revealed evidence of bilateral obstructive emphysema. Chest radiograph revealed bilateral overinflation. Fibro-optic bronchoscopy revealed posterior mediastinal compression. Possibility of congenital cystic lung disease (CCLD) was considered, emphasizing the value of computed tomography (CT) chest, which revealed a cyst probably bronchogenic. Surgical excision was performed with evident histological confirmation of bronchogenic cyst. CONCLUSION: we highlight that in any infant, presented with slowly progressive noisy breathing in the first year of life, CCLD should be considered in the differential diagnosis even with normal X-ray chest. CT chest should be performed for exclusion or diagnosis of the case.

Hemodynamic and catecholamine responses to laryngoscopy with vs. without endotracheal intubation.

To study the relationship between the intensity of the stimulus exerted against the base of the tongue during direct laryngoscopy and the magnitude of associated hemodynamic and catecholamine responses, a study was conducted in 40 ASA I or II patients. Laryngoscopy lasting 40 s was performed with a size 3 Macintosh blade connected to a force-displacement transducer. The intensity of the stimulus exerted during laryngoscopy is expressed by the product of its average force (N) and duration (s) and given as impulse in Ns. Highly significant relationships were found between the impulse during laryngoscopy and the maximal hemodynamic and catecholamine responses. Also, when laryngoscopy was followed by orotracheal intubation, significant relationships were found with steeper slopes of the regression lines for systolic blood pressure, heart rate and plasma epinephrine concentrations. A more rapid regression of hemodynamic data was seen in intubated patients, whereas their plasma catecholamine concentrations regressed more slowly. The mechanisms of the responses to laryngoscopy and orotracheal intubation are proposed to be by somato-visceral reflexes. Stimulation of proprioceptors at the base of the tongue during laryngoscopy induces impulse-dependent increases of systemic blood pressure, heart rate and plasma catecholamine concentrations. Subsequent orotracheal intubation recruits additional receptors that elicit augmented hemodynamic and epinephrine responses as well as some vagal inhibition of the heart.

[Conduction deafness in adults. Diagnostic elements and therapeutic principles]. / Les surdités de transmission de l'adulte. Eléments diagnostiques et principes thérapeutiques.

In the vast majority of cases, conduction deafness is due to a lesion of the eardrum-ossicles system located in the middle ear. The diagnosis, relatively easy, rests on the results of acoumetry (performed with a tuning-fork), audiometry and acoustic impedance measurement. The causes of conduction deafness are multiple and can be divided into 5 categories: major or minor malformations, injuries, tumours, otospongiosis and chronic otitis media. The last two named are the most frequent and must be considered first. Otospongiosis is the most common cause of conduction deafness with healthy typanic membrane. Kophosurgery usually triumphs in this field, even though occasional incidents or accidents must be deplored. Chronic otitis media has different forms and usually succeeds to an inflammatory disease of childhood: serous otitis which is the most obvious common factor in all forms. Despite its apparent complexity, otitis media can be diagnosed by the general practitioner. Although kophosurgery has made remarkable advances, surgical treatment is not always required.

[Pseudotumoral nasopharyngeal sarcoidosis in the child. Apropos of a case]. / Sarcoïdose rhino-pharyngée pseudo-tumorale chez l'enfant. A propos d'une observation.

Rhino-pharyngeal, involvement is rare in sarcoidosis, and exceptional in children. The authors report a case of pseudo-tumoral involvement of the cavum in a 9 year old child, revealed by locoregional complications. Close collaboration between clinicians and the pathologist enabled correct etiological diagnosis.

[Anatomical and functional evaluation 3 and 5 years later of 94 cases of chronic cholesteatomatous otitis media. Clinical and therapeutic implications]. / Bilan anatomique et fonctionnel à 3 et 5 ans de 94 cas d'otite moyenne chronique cholestéatomateuse. Implications cliniques et thérapeutiques.

Anatomical and functional results were evaluated at 3 and 5 years after surgery for chronic cholesteatomatous otitis media in 94 patients treated by the same surgeon between 1975 and 1983. Open techniques predominated and were justified by seven clinical or epidemiologic factors present alone or in association in 80% of cases. Many patients were non-attenders at follow up (40% at 3 years and 70% at 5 years), recovery from their cholesteatoma being noted in 84% and 78% of those attending at 3 and 5 years respectively. Useful audition was recovered in 52%, including 2 of 3 due to an open technique. Petro-mastoid hollow-out with arrangement of cavity and minimal ossicular reconstruction is considered the most effective treatment for this type of affection.

[Anatomical and functional evaluation, after 3 and 5 years, of 94 cases of chronic cholesteatomatous otitis media. Clinical and therapeutic implications]. / Bilan anatomique et fonctionnel à 3 et 5 ans de 94 cas d'otite moyenne chronique cholestéatomateuse. Implications cliniques et thérapeutiques.

Anatomic and functional results are reported after 3 and 5 year follow up of 94 cases of chronic cholesteatomatous otitis operated upon and kept under surveillance by the same surgeon between 1975 and 1983. Open technics dominated and were justified by seven clinical and epidemiologic factors found alone or in combination in 80% of patients. Results must allow for the high rate of non-attenders (40% at 3 years and 70% at 5 years). Recovery from their cholesteatoma was obtained in 84 and 78% of patients after 3 and 5 years respectively, 52% recovering useful hearing, 2 out of 3 of these due to an open technic. Modified radical mastoidectomy is considered to be undoubtedly the most effective treatment for this type of affection.