Fabrication of Multifunctional Nanostructured Porous Materials

Nanostructured porous materials generally, and nanoporous noble metals specifically, have received considerable attention due to their superior chemical and physical properties over nanoparticles and bulk counterparts. This dissertation work aims to develop well-established strategies for the preparation of multifunctional nanostructured porous materials based on the combination of inorganic-chemistry, organic-chemistry and electrochemistry. The preparation strategies involved one or more of the following processes: sol-gel synthesis, co-electrodeposition, metal ions reduction, electropolymerization and dealloying or chemical etching. The study did not stop at the preparation limits but extended to investigate the reaction mechanism behind the formation of these multifunctional nanoporous structures in order to determine the different factors controlling the nanoporous structures formation. First, gold-silica nanocomposites were prepared and used as a building blocks for the fabrication of high surface area gold coral electrodes. Well-controlled surface area enhancement, film thickness and morphology were achieved. An enhancement in the electrode’s surface area up to 57 times relative to the geometric area was achieved. A critical sol-gel monomer concentration was also noted at which the deposited silica around the gold coral was able to stabilize the gold corals and below which the deposited coral structures are not stable. Second, free-standing and transferable strata-like 3D porous polypyrrole nanostructures were obtained from chemical etching of the electrodeposited polypyrrole-silica nanocomposite films. A new reaction mechanism was developed and a new structural directing factor has been discovered for the first time. Finally, silver-rich platinum alloys were prepared and dealloyed in acidic medium to produce 3D bicontinuous nanoporous platinum nanorods and films with a nanoporous gold-like structure. The 3D-BC-NP-Pt displayed high surface area, typical electrochemical sensing properties in an aqueous medium, and exceptional electrochemical sensing capability in a complex biofouling environment containing fibrinogen. The 3D-BC-NP-Pt displayed high catalytic activity toward the methanol electro-oxidation that is 30 times higher that of planar platinum and high volumetric capacitance of 400 F/cm3. These findings will pave the way toward the development of high performance and reliable electrodes for catalysis, sensing, high power outputs fuel cells, battery-like supercapacitors and miniaturized device applications

Prevalence of cesarean section on demand in Assiut Governorate, Egypt

Background: The current study aims to evaluate the prevalence of CS on demand in Women's health hospital, Assiut University and Abnob Central Hospital in Assiut Governorate, Egypt.Methods: A cross sectional study conducted in Assiut Women Health Hospital and Abnob central hospital from January 2017 to December 2017. The total number of cesarean section done was 180 cases and the number of CS on demand was 64 (35.6%). The demographic data were collected by one of the study investigators. Women were asked about the causes of requesting CS before surgery.Results: The study group was 64 women with age ranging from 18-40 years old, 40 primipara and 24 multipara. Of those 24 women, 21 of them previously delivered vaginally and only 3 women delivered by emergency CS. Twenty- six women had a history of previous abortion. Fear of pain was the main cause for CS on demand in the whole study participants (57.8%). In primipara, the main cause for requesting CS is fear of pain in 62.5% of participants followed by fear on the baby in 45 % of women. On the other hand, in multipara, the main cause for CS on demand was bad history of previous experience (60%) followed by fear of pain in 50% of cases. There was statistical significant difference between both groups in only two causes; fear of pelvic floor injuries (50% in multipara vs. 20% in primipara, p=0.02) and bad history of previous experience (60% in multipara vs. 0% in primipara, p=0.001). Other causes were not statistically different.Conclusions: The incidence of cesarean sections performed on request without medical indications is rising. The reasons for this are not only for perceived medical benefit, but also due to social, cultural, and psychological factors

C-reactive protein as a screening test for gestational diabetes mellitus in first-trimester of pregnancy: a prospective cohort study

Background: The current study aims to determine if increased inflammation identified by increased C-reactive protein (CRP) level is associated with the subsequent development of gestational diabetes mellitus (GDM).Methods: A prospective cohort study conducted at a tertiary University Hospital included 496 booking for their antenatal care visit between 10-12 weeks of gestation. They were tested for presence of CRP in blood. All women without a history of antenatal type 1 or type 2 diabetes undergo routine GDM screening with the 50-g oral glucose-loading test (GLT) between 24 and 28 weeks 'gestation. Women whose 1-h post-loading plasma glucose level >7.8 mmol/l (>140 mg/dl) undergo a diagnostic, fasting, 100-g, 3-h oral glucose tolerance test (OGTT) within 1-2 weeks following the GLT.Results: Among these 496 women, a total of 27 women (5.4%) were diagnosed as GDM and 10 women (2.0%) were diagnosed as IGT at week 24-28. The CRP was positive and higher in the GDM diagnosed group (p=0.000) compared to those who did not develop GDM. CRP was positively correlated with diagnosis of GDM (r=0.438, p=0.012).Conclusions: There is an association between first-trimester inflammation, marked by increased CRP levels and subsequent risk of GDM

STRESS ANALYSIS COMPARING EFFECT OF TWO DIFFERENT CAD-CAM IMPLANT SUPERSTRUCTURE MATERIALS (IN-VITRO STUDY)

Purpose: This study was conducted to evaluate the micro-strain around dental implant using two different CAD/CAM crown fabricated materials through strain gauge analysis. Materials and Methods: Five dental implants were fixed in a 5 previously drilled solid rigid polyurethane test blocks in the edentulous area with neighboring abutments mesial and distal printed out using special 3D Dental printer, Cyanoacrylate adhesive was then used to fix the printed-out part on to the polyurethane test blocks, creating the bounded saddle replicas. Ten CAD/CAM screw retained crowns were fabricated; five Enamic crowns from vita enamic blocks, and five zirconia crowns from presintered katana zirconium blocks. Each crown was cemented to abutment and screwed over the implant fixture. Two strain gauges were installed on their corresponding prepared sites to measure the micro-strains in the medium surrounding the implant. For each tested implant, loads were applied by a universal testing machine, micro-strains were recorded with the strain gauges and stress distribution around the implant was statistically evaluated. Results: Micro-strain recording revealed a statistically significant difference in mean micro-strain recording applied in central fossa between Zirconia and Enamic, for both the buccal and lingual measurements, Enamic was significantly lower than Zirconia. Conclusion: The modulus of elasticity of restorative materials has a meaningful effect on forces applied to dental implant and transmitted to the supporting bone

Safety and efficacy of venous mechano-chemical ablation of the great saphenous vein

Introduction: Endovenous mechano-chemical ablation of the incompetent great saphenous vein (MOCA) is a new technique that combines mechanical endothelial injury and infusion of a sclerosant agent. Material and methods: This is a prospective study was conducted on 40 patients who presented with the chronic venous disease at Kasr Al Ainy outpatient vascular surgery clinic with CEAP classification namely C2-C6. Results: A total of 40 patients were presented with great saphenous vein incompetency, the mean age was (30), 23 patients were male and 17 were female. The vein occlusion rate at one month was 93 percent and at six months was 87 percent respectively. Conclusions: Endovenous mechanochemical ablation is a safe and effective method for the management of incompetent great saphenous veins compared to open surgery

Sulfur-Enriched Nanoporous Carbon: A Novel Approach to CO₂ Adsorption

Carbon dioxide (CO2) intake plays a vital role in sustaining the environmental balance by influencing global carbon dynamics and climatic stability. This work addresses the production of sulfur-doped porous nanocarbons (SDCs) as prospective sorbents for CO2 capture. SDCs were fabricated by utilizing coconut shell as a carbon precursor and potassium persulfate as both a chemical activating agent and a sulfur dopant. The incorporation of sulfur functionalities into carbon matrices creates structural variability and active sites, boosting CO2 absorption capabilities. Sulfur's peculiar electrical structure allows greater intermolecular interactions with CO2, enhancing adsorption affinities. According to the experimental data, the CO2 uptake was best measured as 3.37 mmol/g at 0 °C and 1 bar and 2.56 mmol/g at 25 °C and 1 bar. The results show that the higher porosity of SDC materials adds to a large amplification in the CO2 uptake capability. The work underlines the delicate interaction between sulfur doping, morphological porosity, and surface reactivity in enhancing the effectiveness of CO2 sequestration. SDC materials hold considerable promise in tackling the present ecological concerns and developing CO22collection techniques. The suggested single-step synthesis technique described here provides a sustainable and environmentally friendly method for synthesizing SDCs for carbon capture applications

N4-Substituted Piperazinyl Norfloxacin Derivatives with Broad-Spectrum Activity and Multiple Mechanisms on Gyrase, Topoisomerase IV, and Bacterial Cell Wall Synthesis

Fluoroquinolones are an important class of antibiotics with broad-spectrum antibacterial and antitubercular activity. Here, we describe the design and synthesis of a series of 38 N4-substituted piperazinyl norfloxacin derivatives. Their activity and mechanism of action were characterized using in silico, in vitro, and in vivo approaches. Several compounds displayed interesting activities against both Gram-negative and Gram-positive bacteria, and few displayed antimycobacterial activity, whereby some were as potent as norfloxacin and ciprofloxacin. Molecular docking experiments suggested that the new derivatives inhibit both DNA gyrase and DNA topoisomerase IV in a similar manner as norfloxacin. Selecting the most promising candidates for experimental mode of action analysis, we confirmed DNA gyrase and topoisomerase IV as targets of all tested compounds using enzymatic in vitro assays. Phenotypic analysis of both Escherichia coli and Bacillus subtilis confirmed a typical gyrase inhibition phenotype for all of the tested compounds. Assessment of possible additional targets revealed three compounds with unique effects on the B. subtilis cell wall synthesis machinery, suggesting that they may have an additional target in this pathway. Comparison with known cell wall synthesis inhibitors showed that the new compounds elicit a distinct and, so far, unique phenotype, suggesting that they act differently from known cell wall synthesis inhibitors. Interestingly, our phenotypic analysis revealed that both norfloxacin and ciprofloxacin displayed additional cellular effects as well, which may be indicative of the so far unknown additional mechanisms of fluoroquinolones

Using probiotics to improve the utilization of chopped dried date palm leaves as a feed in diets of growing Farafra lambs

The study determined the ability of three probiotics to improve the nutritional value of date palm leaves in diets of growing lambs. Twenty male Farafra lambs (26 ± 0.33 kg) were randomly allocated to one of four treatments (n = 6) and fed: a control or basal diet (C; 70% concentrate + 30% date palm leaves without additives) and supplemented with Bacillofort containing 2 × 1011 CFU of Bacillus subtilis/g (BAC treatment), Lacotpro containing 1 × 1012 CFU of Lactobacillus acidophilus/g (LAC treatment) or ZAD containing 6 × 108 CFU of R. albus/g (ZAD treatment) at 4 g of all additives for 150 days. As a result of this study, LAC improved (P < 0.05) growth performance and feed efficiency compared to control. Additives increased (P = 0.001) concentrations of albumin, triiodothyronine, and thyroxine, hemoglobin concentration and red blood cells and decreased (P = 0.001) globulin and urea-N. Additives increased hot carcass (P = 0.040) while BAC increased Longissimus dorsi, meat and fat without affecting water holding capacity compared to other treatments. In the metabolism experiment, BAC increased the digestibility of crude protein, while BAC and ZAD increased the digestibility of dry matter, organic matter, and neutral detergent fiber. Additives did not affect nitrogen (N) intake and urinary N; however, decreased fecal N and increased N balance compared to the control. BAC and ZAD increased ruminal volatile fatty acids concentration compared to the control. Based on our results, Lacotpro could be used to improve growth performance and feed efficiency, while Bacillofort could be used to improve meat quality of in lambs