41 research outputs found
Alcohol-Selective Oxidation in Water under Mild Conditions via a Novel Approach to Hybrid Composite Photocatalysts
The oxidation of alcohols to carbonyl compounds in a clean fashion (i.e., with water as a solvent or under solvent-free conditions, and using O2 or H2O2 as the primary oxidant) is the subject of considerable research efforts. A new approach for the selective oxidation of soluble aromatic alcohols in water under mild conditions via a novel composite photocatalyst has been developed. The catalyst is synthesized by grafting 4-(4-(4-hydroxyphenylimino)cyclohexa-2,5dienylideneamino)phenol and silver nanoparticles onto the surface of moderately crystalline titanium dioxide. The titanium dioxide-based composite was first extensively characterized and then employed in the catalytic oxidation of 4-methoxybenzyl alcohol to 4-methoxybenzaldehyde under UV irradiation in water at room temperature. The corresponding aldehyde was obtained with unprecedented high selectivity (up to 86 %). The method is general and opens the route to fabrication of photocatalytic composites based on titanium dioxide functionalized with shuttle organic molecules and metal nanoparticles for a variety of oxidative conversions
Chest wall reconstruction still has place in Today’s modern practice:" a tertiary center experience"
Background: The key factor following chest wall resection is the preservation of the stability and integrity of the chest wall to support the respiration and protect the underlying organs. The present study aims to evaluate the use of the available grafts and prosthetic materials at our center in chest wall reconstruction with adherence to the proper surgical techniques, good perioperative and postoperative care to obtain good results.
Methods: This is a retrospective single center study that concludes all patients underwent chest wall reconstruction for a variety of defects resulting from resection of tumors, trauma due to primarily firearms or motor car accidents, resection of radio necrotic tissues, infection and dehiscence of median sternotomy wounds after cardiac surgery.
Results: Study population consisted of 30 patients between January 2015and may 2018, among them were 20 male (70%) and 10 female patients (30%), with a median age of 43 ± 16.3 years, resection and reconstruction was performed in 23 cases (15 neoplastic,5 infective and 3 firearm cases) while reconstruction alone was performed in 7 (traumatic flail chest) cases. Eighteen patients, underwent rib resection with an average 4.18 ± 2.2 ribs (range 2-6). Associated lung resection was performed in 5 patients (27.8 %): diaphragmatic resection was done in 2 cases in addition total sternal resection was performed in 5 cases. Most of the patients (96.7%) had primary healing of their wounds. there was one death (3.3%) in the early postoperative period. The average length of hospital stay for all patients was 8.7 days (range: 5–15). Respiratory complications occurred in three cases in the form of atelectasis and pneumonia at the ipsilateral side of reconstruction. Three cases suffered wound seroma which successfully managed by daily dressing and antibiotic coverage.
Conclusions: according to our study and the analysis of similar studies, adequate perioperative preparation of patient undergoing chest wall resection and reconstruction with adherence to effective surgical techniques allowed us to use the available materials at our center for chest wall reconstruction with good and effective results without adding burden in terms of cost on the patient
Interspecies Interaction between Pseudomonas aeruginosa, Staphylococcus aureus and E. coli in vitro
Microbial interactions are frequently categorized according to how they affect each population in a binary system. We aimed to determine the interaction between P . aeruginosa, S . aureus, and E . coli in-vitro. In this experimental hospitalized patients’ sputum, urine, and blood samples were used to collect a total of 90 clinical isolates for the study in Damanhour Medical National Institute, Behira, Egypt, followed by accurate identification and testing for antibiotic sensitivity. To examine the effect of the supernatant of P. aeruginosa on S. aureus and E. coli determined MIC using broth microdilution method. We also measured the activity of lasA protease by assessing the S. aureus cell lysis potential of P. aeruginosa culture supernatants. Extraction of pyocyanin was made to determine the change in the cell nature of S. aureus upon exposure to pyocyanin by using a scanning electron microscope and the shape of colonies on the culture media was determined. Finally, we detect lasA, operon phz, phzM, phzS and rhlAB genes for P. aeruginosa. P. aeruginosa showed a great impact on S. aureus isolates resistant to different antibiotics as it facilitates their killing and may drive the normal colonies of S. aureus into SCVs. The ability to form biofilm by S. aureus and E. coli decreased in the presence of Pseudomonas supernatant
Theoretical and experimental insights into the C-steel aqueous corrosion inhibition at elevated temperatures in 1.0M HCl via multi-carbonyl Gemini cationic surfactants
Despite corrosion being an inevitable process, researchers strive to control corrosion. In this study, our goal was to prepare two amido Gemini cationic surfactants, LAPG and MAPG, each with different alkyl chains and multiple carbonyl groups as rich electronic rich centers. We aimed to evaluate these surfactants as potential corrosion inhibitors for carbon steel (CS) in 1M HCl at temperatures of 25-55 ± 0.1°C. In theoretical investigations, DFT parameters and Mont Carlo simulation were run to predict the adsorption affinity and reactive sites of the LAPG and MAPG molecules. Their efficacy was investigated experimentally considering weight loss and electrochemical techniques. The Tafel polarization revealed that at 0.1mM of LAPG and MAPG, the corrosion current density (i corr) of CS was reduced to the lowest extent (75.56 and 53.82μAcm-2) compared to 529.3μAcm-2 in the absence of the inhibitors. EIS data suggests the enhancement of the thickness of the adsorbed layers of the studied compounds from the decrease of the double-layer capacitance C dl values. The Langmuir isotherm explained the adoption phenomena of these compounds at 25-55 ± 0.1°C. Activation and adsorption thermodynamic parameters predicted the chemisorption behavior of these molecules onto the steel surface. AFM and XPS tools confirm the CS surface protection due to these inhibitors' adsorbed layer. A parallel study showed the superiority of these corrosion inhibitors in HCl compared with those reported earlier, making these compounds highly promising corrosion inhibitors, especially in high-temperature acidic environments
Mixed Climatology, Non-synoptic Phenomena and Downburst Wind Loading of Structures
Modern wind engineering was born in 1961, when Davenport published a paper in which meteorology, micrometeorology, climatology, bluff-body aerodynamics and structural dynamics were embedded within a homogeneous framework of the wind loading of structures called today \u201cDavenport chain\u201d. Idealizing the wind with a synoptic extra-tropical cyclone, this model was so simple and elegant as to become a sort of axiom. Between 1976 and 1977 Gomes and Vickery separated thunderstorm from non-thunderstorm winds, determined their disjoint extreme distributions and derived a mixed model later extended to other Aeolian phenomena; this study, which represents a milestone in mixed climatology, proved the impossibility of labelling a heterogeneous range of events by the generic term \u201cwind\u201d. This paper provides an overview of this matter, with particular regard to the studies conducted at the University of Genova on thunderstorm downbursts
Operative bzw. konservative Therapie bei flail chest - Ergebnisse und funktionelle Aspekte
Insulin-like growth factor 1 and sex hormones for assessment of anthropometric and pubertal growth of Egyptian children and adolescents with type 1 diabetes mellitus (single center study)
Abstract Background This study aimed to assess the anthropometric measures and pubertal growth of children and adolescents with Type 1 diabetes mellitus (T1DM) and to detect risk determinants affecting these measures and their link to glycemic control. Patients and methods Two hundred children and adolescents were assessed using anthropometric measurements. Those with short stature were further evaluated using insulin-like growth factor 1 (IGF-1), bone age, and thyroid profile, while those with delayed puberty were evaluated using sex hormones and pituitary gonadotropins assay. Results We found that 12.5% of our patients were short (height SDS  8.2, and albumin/creatinine ratio > 8 (p < 0.05). Conclusion Children with uncontrolled T1DM are at risk of short stature and delayed puberty. Diabetes duration and control seem to be independent risk factors for short stature