Synthesis and Characterization of a Tertiary Composite of Cu, Mn, and g-C3N4: An Efficient Visible Light-Active Catalyst for Wastewater Treatment.

In this study, a tertiary composite of graphitic carbon nitride (GCN) with copper and manganese is utilized for photocatalytic degradation to add to efforts for tackling environmental pollution problems. The photocatalytic efficiency of GCN is enhanced with the doping of copper and manganese. This composite is prepared using melamine thermal self-condensation. The formation and characteristics of the composite Cu-Mn-doped GCN are affirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet (UV), and Fourier transform infrared spectroscopy (FTIR). This composite has been used for the degradation of an organic dye (methylene blue (MB)) from water at neutral conditions (pH = 7) of the solution. The percentage photocatalytic degradation of MB by Cu-Mn-doped GCN is higher than that of Cu-GCN and GCN. The prepared composite enhances the degradation of methylene blue (MB) from 5 to 98% under sunlight. The photocatalytic degradation is enhanced owing to the reduction of hole-electron recombination in GCN, enhanced surface area, and extended sunlight utilization by the doped Cu and Mn.

A Rare Case of Huge Schistosomiasis-Associated Cecal Polyp Mimicking Colon Carcinoma.

Schistosomiasis is a parasitic infection caused by Schistosoma species, commonly found in tropical and subtropical regions. It affects millions of people worldwide and can lead to different clinical presentations like abdominal pain, weight loss, anemia, and chronic colonic schistosomiasis. In rare cases, chronic infection can result in the development of polyps, which can mimic colon carcinoma, posing a diagnostic challenge. Here, we present a rare case of a huge Schistosomiasis-associated cecal polyp in a patient initially suspected to have colon cancer. The patient's clinical history and the histopathological analysis confirmed the diagnosis, emphasizing the importance of considering parasitic infections in the differential diagnosis of gastrointestinal polyps in Schistosomiasis-endemic areas. This case report highlights the need for increased awareness among healthcare professionals of the potential for Schistosomiasis-associated polyps and the importance of multidisciplinary management in such cases.

Development of Heavy-Weight Hematite-Based Geopolymers for Oil and Gas Well Cementing.

In the petroleum industry, ordinary Portland cement (OPC) is utilized for different cementing applications. Yet, there are some technical and environmental issues for the usage of OPC in well cementing. The technical problems include gas invasion while setting, instability at corrosive environments, cement failure while perforation and fracturing due to high stiffness and brittleness, and strength reduction and thermal instability at elevated temperatures. Moreover, OPC production consumes massive energy and generates high greenhouse gas emissions. This study introduced the first hematite-based class F fly ash geopolymer formulation that can be used in oil and gas well cementing. Different properties of the designed slurry and hardened samples such as rheology, thickening time, strength, and elastic and petrophysical properties were evaluated. Moreover, mixability and pumpability challenges of heavy-weight geopolymer slurries were investigated. Unlike most of the studies in the literature, this work used 4 M NaOH solution only as an activator that can reduce the overall cost. The results showed that increasing the hematite percentage significantly decreased the thickening time. The developed formulation fell within the recommended fluid loss ranges for some cementing applications without using a fluid loss control additive. A proposed mixture of retarder and superplasticizer was introduced to enhance the thickening time by almost 5 times. The compressive strength increased by 49% and the tensile strength was enhanced by 27.4% by increasing the curing time from 1 to 7 days. The improvement in both compressive and tensile strength with curing time indicated that the geopolymerization reaction continued for extended time but with a smaller rate. The developed slurry acted more like a power law fluid at low temperatures and more like a Bingham plastic fluid at high temperatures. The elastic properties of the developed geopolymer samples proved that they are more flexible than some cement systems.

Assessing the Factors Affecting the Use of the Precast Concrete Systems in Saudi Arabia Based on Stakeholders Survey.

The construction industry in Saudi Arabia (SA) is improving and growing rapidly. The use of precast concrete systems (PCS) proposes numerous advantages such as rapid construction, high-quality construction, sustainability, and efficient associated costs, which are all aligned with the Saudi Arabia 2030 vision. These advantages could be the most important factors in deciding to use PCS as a construction system. However, other factors could adversely affect the use of PCS in SA. These factors are not identified in the existing literature and this study addresses this gap. The study investigates the factors affecting the use of PCS in SA. These factors are identified through an online industry survey, and 171 responses were recorded from various stakeholders. The results present the positive and negative factors affecting the use of PCS in SA from the industry perspective. Recommendations are proposed to overcome the negative factors and increase the use of PCS in SA.

Management of frontal sinus fungal osteomyelitis in the COVID 19 era: A case series.

The aim of this study was to review different approaches and outcomes in the management of post-COVID-19 frontal sinus fungal osteomyelitis. The study included 19 patients with frontal sinus fungal osteomyelitis. The main line of treatment was surgical debridement (sequestrectomy). Approaches included combined external and endoscopic approaches (n = 15) and pure endoscopic approaches (n = 4) according to the extent and accessibility of the sequestrum. Postoperative healing was satisfactory in all patients. All patients returned to their normal daily activity within 4-6 weeks, without residual or recurrent frontal sinus infection, osteomyelitis or need for revision procedures. Within the limitation of this case series, it seems that there is no need to adopt a new therapy regimen for treatment of frontal sinus fungal osteomyelitis because the conventional and well-known treatment approach combining surgery and antifungal drugs seems to work well. However, early, and adequate debridement and sequestrectomy is crucial. Furthermore, an open approach may be required according to the extent of osteomyelitis.

Unmodified Gum Arabic/Chitosan/Nanohydroxyapatite Nanocomposite Hydrogels as Potential Scaffolds for Bone Regeneration.

In this work, physical cross-linking was used to create nanocomposite hydrogels composed of unmodified gum arabic (GA), chitosan (Ch), and natural nanohydroxyapatite (nHA), using an acrylic acid (AA) solvent. Different GA/chitosan contents (15%, 25%, and 35% of the used AA) as well as different nHA contents (2, 5, and 10 wt.%), were used and studied. The natural nHA and the fabricated GA/Ch/nHA nanocomposite hydrogels were characterized using different analysis techniques. Using acrylic acid solvent produced novel hydrogels with compressive strength of 15.43-22.20 MPa which is similar to that of natural cortical bone. The addition of natural nHA to the hydrogels resulted in a significant improvement in the compressive strength of the fabricated hydrogels. In vitro studies of water absorption and degradation-and in vivo studies-confirmed that the nanocomposite hydrogels described here are biodegradable, biocompatible, and facilitate apatite formation while immersed in the simulated body fluid (SBF). In light of these findings, the GA/Ch/nHA nanocomposite hydrogels are recommended for preparing bioactive nanoscaffolds for testing in bone regeneration applications.

Nasal Spine of the Frontal Bone: A Consistent Landmark for Safe Outside-In Frontal Drill-Out.

BACKGROUND: Outside-in frontal drill out entails drilling the frontal sinus floor in the midline before identifying and dissecting the frontal recesses. It is a more direct approach, especially in revision surgery or cases with challenging anatomy. OBJECTIVES: The aim of this study was to highlight the anatomical and surgical concepts for easy and safe outside-in frontal drill out by a preclinical anatomic study on cadaveric heads. In addition, to review our experience with this approach over a 5-year period for challenging frontal sinus pathologies. METHODS: The study included 2 sectors; a preclinical study, in which 5 cadaveric heads were dissected and studied to identify and standardize the anatomical landmarks of this approach. This was followed by a clinical case series which included 22 patients with challenging frontal sinus pathologies that were treated with this proposed approach. RESULTS: We concluded from the anatomic study that the nasal spine of the frontal bone (NSFB) and its anatomical orientation in relation to the nasal branch of the anterior ethmoidal artery (NBAEA) is a consistent landmark that enables the surgeon to identify the correct coronal trajectory of drilling to avoid injury of the cribriform and the skull base. The clinical case series included 22 patients that were successfully treated with the proposed approach. No intraoperative nor postoperative complications were reported in this study. Long-term follow-up showed that the frontal neo-ostium was patent in all cases (n = 22). CONCLUSION: Outside-in frontal drill-out is a safe and easy approach; especially in challenging frontal sinus pathologies; using the NSFB and its anatomical coronal orientation to the NBAEA as a consistent landmark, anterior to the skull base. This approach offers early, safe, and direct bone removal without the need for initial identification and dissection of the frontal recess.

Environmentally Friendly Polyvinyl Alcohol-Alginate/Bentonite Semi-Interpenetrating Polymer Network Nanocomposite Hydrogel Beads as an Efficient Adsorbent for the Removal of Methylene Blue from Aqueous Solution.

Hazardous chemicals like toxic organic dyes are very harmful to the environment and their removal is quite challenging. Therefore there is a necessity to develop techniques, which are environment friendly, cost-effective and easily available in nature for water purification and remediation. The present research work is focused on the development` and characterization of the ecofriendly semi-interpenetrating polymer network (semi-IPN) nanocomposite hydrogels composed of polyvinyl alcohol (PVA) and alginate (Alg) hydrogel beads incorporating natural bentonite (Bent) clay as a beneficial adsorbent for the removal of toxic methylene blue (MB) from aqueous solution. PVA-Alg/Bent nanocomposite hydrogel beads with different Bent content (0, 10, 20, and 30 wt%) were synthesized via external ionic gelation method. The designed porous and steady structure beads were characterized by the use of Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). The performance of the beads as MB adsorbents was investigated by treating aqueous solutions in batch mode. The experimental results indicated that the incorporation of Bent (30 wt%) in the nanocomposite formulation sustained the porous structure, preserved water uptake, and increased MB removal efficiency by 230% compared to empty beads. Designed beads possessed higher affinity to MB at high pH 8, 30 °C, and fitted well to pseudo-second-order kinetic model with a high correlation coefficient. Moreover, the designed beads had good stability and reusability as they exhibited excellent removal efficiency (90%) after six consecutive adsorption-desorption cycles. The adsorption process was found be combination of both monolayer adsorption on homogeneous surface and multilayer adsorption on heterogeneous surface. The maximum adsorption capacity of the designed beads system as calculated by Langmuir isotherm was found to be 51.34 mg/g, which is in good agreement with the reported clay-related adsorbents. The designed semi-IPN PVA-Alg/Bent nanocomposite hydrogel beads demonstrated good adsorbent properties and could be potentially used for MB removal from polluted water.

Surface Morphology and Mechanical Properties of Polyether Ether Ketone (PEEK) Nanocomposites Reinforced by Nano-Sized Silica (SiO2) for Prosthodontics and Restorative Dentistry.

In the field of orthopedics and traumatology, polyether ether ketone (PEEK) serves a significant role as a suitable alternative to traditional metal-based implants like titanium. PEEK is being used more commonly to replace traditional dental products. For bonding with various adhesive agents and preserved teeth, the surface alteration of PEEK was investigated. The aim of this research was to understand how different types and contents of nano-sized silica (SiO2) fillers influenced the surface and mechanical properties of PEEK nanocomposites used in prosthodontics. In this work, PEEK based nanocomposites containing hydrophilic or hydrophobic nano-silica were prepared by a compression molding technique. The influence of nano-SiO2 type and content (10, 20 and 30% wt) on surface properties of the resultant nanocomposites was investigated by the use of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), surface roughness analysis, and contact angle measurement. The crystalline structures of PEEK/SiO2 nanocomposites were examined by X-ray diffraction (XRD) spectroscopy. Mechanical properties were measured by microhardness, elastic compression modulus, and flexural strength. All nanocomposites showed increased surface roughness compared to pure PEEK. SEM images revealed that nanocomposites filled with low content hydrophobic nano-SiO2 showed uniform dispersion within the PEEK matrix. The introduction of 10 wt% of hydrophobic nano-SiO2 to the PEEK matrix improved elastic modulus, flexural strength, and microhardness, according to the findings. The addition of nano-SiO2 fillers in a higher weight percentage, over 10%, significantly damages the mechanical characteristics of the resultant nanocomposite. On the basis of the obtained results, PEEK/SiO2 nanocomposites loaded with low content hydrophobic nano-SiO2 are recommended as promising candidates for orthopedic and prosthodontics materials.

Viscoelasticity, Mechanical Properties, and In Vitro Bioactivity of Gelatin/Borosilicate Bioactive Glass Nanocomposite Hydrogels as Potential Scaffolds for Bone Regeneration.

Chemical cross-linking was used to create nanocomposite hydrogels made up of gelatin (G) and borosilicate bioactive glass (BBG) with different content (0, 3, and 5 wt.%). The G/BBG nanocomposite hydrogels were studied for their morphology, mechanical properties, and viscoelasticity. SEM images revealed a macroporous interconnected structure with particles scattered across the pore walls. Studies of water absorption and degradation confirmed that the nanocomposite scaffolds were hydrophilic and biodegradable. The addition of 5% BBG to the scaffold formulations increased the compressive modulus by 413% and the compressive intensity by 20%, respectively. At all frequency ranges tested, the storage modulus (G') was greater than the loss modulus (G″), revealing a self-standing elastic nanocomposite hydrogel. The nanocomposite scaffolds facilitated apatite formation while immersed in simulated body fluid (SBF). According to the findings, G/BBG nanocomposite scaffolds could be a promising biomaterial for bone regeneration.

Local treatment of experimental mandibular osteomyelitis with an injectable biomimetic gentamicin hydrogel using a new rabbit model.

Mandibular osteomyelitis (OM) is a challenging disease. Our objective was to assess a new OM model in rabbits induced by arsenic trioxide and to assess the efficacy of local treatment of OM using injectable gentamicin-collagen hydrogels (GNT-COLL). OM was induced unilaterally by controlled confinement of arsenic trioxide paste to the root canal of lower incisors of rabbits, while OM progression was characterized for 16 weeks. On the other hand, two injectable COLL hydrogels functionalized with GNT were prepared and characterized for physicochemical properties; a simple GNT-COLL and a nanohydroxyapatite (nHA)- loaded hydrogel (GNT-COLL/nHA). The two hydrogels were evaluated to treat OM model, while a multidose intramuscular GNT solution served as positive control. Outcomes were assessed by standard methods at 4 and 12 weeks post-surgery. The clinical, radiographical, and histopathological findings provided evidence for the validity of the arsenic-induced OM. The results demonstrated that a single intra-lesional injection of the two hydrogels was more suppressive to OM compared to multidose systemic GNT. The composite GNT-COLL/nHA hydrogel proved to induce early preservation of alveolar bone (ridge) length and higher amount of bone area\total area at 4 weeks (40.53% ± 2.34) followed by GNT-COLL (32.21% ± 0.72). On the other hand, the positive control group revealed the least ridge length and bone area\total area (26.22% ± 1.32) at 4 weeks. Both hydrogels successfully arrested OM with no signs of recurrence for up to 12 weeks. Therefore, results support the greater advantages of the composite hydrogel as an osteogenic/antibiotic delivery system in OM treatment.

Field Validation of Concrete Transport Property Measurement Methods.

Reinforcing steel corrosion, caused by chloride ingress into concrete, is the leading cause of reinforced concrete deterioration. One of the main findings in the literature for reducing chloride ingress is the improvement of the durability characteristics of concrete by the addition of supplementary cementitious materials (SCMs) and/or chemical agents to concrete mixtures. In this study, standard ASTM tests-such as rapid chloride permeability (RCPT), bulk diffusion and sorptivity tests-were used to measure concrete properties such as porosity, sorptivity, salt diffusion, and permeability. Eight different mixtures, prepared with different SCMs and corrosion inhibitors, were tested. Apparent and effective chloride diffusion coefficients were calculated using bound chloride isotherms and time-dependent decrease in diffusion. Diffusion coefficients decreased with time, especially with the addition of SCMs and corrosion inhibitors. The apparent diffusion coefficient calculated using the error function was slightly lower than the effective diffusion coefficient; however, there was a linear trend between the two. The formation factor was found to correlate with the effective diffusion coefficient. The results of the laboratory tests were compared and benchmarked to their counterparts in the marine exposure site in the Arabian Gulf in order to identify laboratory key tests to predict concrete durability. The overall performance of concrete containing SCMs, especially fly ash, were the best among the other mixtures in the laboratory and the field.

Challenging tracheal resection anastomosis: Case series.

OBJECTIVES: This study was conducted to review our experience in Otorhinolaryngology Department, Mansoura University Hospitals, Egypt, in the last 2 years in the management of high-risk patients who underwent cricotracheal resection due to different pathologies. METHODS: This case series included nine patients with severe, grade III or IV subglottic / cervical tracheal stenosis. These patients were considered high risk patients due to unusual pathology / etiology of stenosis or associated surgical field morbidity. Four patients had recurrent stenosis after previous unsuccessful cricotracheal resection, three patients had subglottic stenosis due to external neck trauma which compromised the surgical field. One patient had upper tracheal neoplasm, and in 1 patient there was upper tracheal stenosis associated with tracheo-esophageal fistula. RESULTS: Successful decannulation was achieved in all patients (n = 9) without any reported major intraoperative or postoperative compilations. CONCLUSION: Cases of subglottic / upper tracheal stenosis due to uncommon pathologies like neoplastic lesions, external neck trauma compromising the surgical field and revision cricotracheal resection, can be successfully managed by cricotracheal resection. However, a highly skilled team, well familiar with these surgeries, is mandatory to achieve an optimum outcome.

Endoscopic stapedotomy: Merits and demerits.

INTRODUCTION: Surgical microscopes are still preferred to perform stapes surgery; but the use of the endoscopes would offer much benefits such as good panoramic view and easy accessibility to the oval window niche, the stapes and facial nerve. In this study, we aimed to analyze and compare the outcomes and complications of endoscopic versus microscopic stapes surgery. PATIENTS AND METHODS: This work was done at the Department of Otorhinolaryngology, Faculty of Medicine, Mansoura University, Egypt, between September 2015 and July 2016. The patients; diagnosed as having otosclerosis and full filled the selection criteria; were randomly divided into 2 groups. RESULTS: The group A (microscopic group) included 28 patients (aged 19-60 years) and the group B (endoscopic group) included 14 patients (aged 22-56 years). Mean follow-up durations were 4.5 months (1-8.5) in the endoscopic group and 5.5 months (1.5-8) in the microscopic group. The difference in preoperative and postoperative air-bone gap in two groups was statistically significant (p = 0.031). But there was no statistical difference for hearing results between two groups and the two techniques have similar audiological outcomes. The main merits of endoscopic stapedotomy are the good quality panoramic image, well identification and visualization of vital structures of the middle ear, minimal handling of chorda tympani nerve if needed with practically no curettage of bony wall. CONCLUSIONS: The present series shows that it is possible to perform stapes surgery using only the 4mm in diameter and 18cm long endoscopes of different angulations, without major difficulties.

Surgical correction of bifid nose.

OBJECTIVES: Evaluation of the aesthetic outcome and functional aspect after surgical correction of bifid nose by combined Millard forked flap with external rhinoplasty BACKGROUND: Bifid nose is a rare congenital anomaly that results during facial development but the explicit mechanism is not clearly understood. Clinical findings are quite variable with a wide range of severity. Surgical correction still represents great challenge to facial plastic surgeons; extensive deformities in many cases, rarity of condition and paucity of publications are contributing factors. METHODS: Surgical correction of six patients with bifid nose by a combined Millard forked flap with external rhinoplasty RESULTS: The aesthetic and functional outcomes were acceptable for all patients and parents. There were no considerable postoperative complications. CONCLUSIONS: This approach is highly effective for various grades of bifid nose. Early management is preferable to avoid psychological morbidity. Secondary rhinoplasty is usually needed for cosmetic refinement.

Cervical sympathetic schwannoma with postoperative first bite syndrome.

Extracranial schwannomas occurring in the head and neck region may arise from cranial, peripheral or autonomic nerves. Determination of the nerve of origin is not often made until the time of surgery. Schwannomas arising from the cervical sympathetic chain are extremely rare. These interesting tumors along with schwannomas in general and the remaining class of neurogenic tumors are known for their ability to mimic the physical and radiological findings of carotid body tumors. Surgery is the treatment of choice and major complications are infrequent. However, we report a case of cervical sympathetic chain schwannoma with postoperative first bite syndrome.

Pepsin assay: a marker for reflux in pediatric glue ear.

OBJECTIVE: To evaluate if analysis of pepsin/pepsinogen in middle ear effusions can be considered a diagnostic marker for laryngopharyngeal reflux (LPR) in children with otitis media with effusion (OME). MATERIAL AND METHODS: Ambulatory 24-hour dual-probe pH monitoring was carried out on 31 children with OME. Middle ear effusions were collected from 17 children during myringotomy. Total pepsin/pepsinogen concentrations in effusions were measured by ELISA using antipepsin antibody. RESULTS: Dual-probe pH monitoring showed that 22/31 (71%) of the studied children had significant LPR. The concentrations of pepsin/pepsinogen in middle ear effusions, ranged from 0.085 to 5.02 microg/ml, were found to be up to 4.5 to 231.44 times higher than the serum levels. There was a significant positive correlation between the level of pepsin/pepsinogen assayed in the effusions of the 17 children and the number of pharyngeal reflux episodes measured by pH monitoring. CONCLUSIONS: Control of LPR may be an essential component in the successful management of OME in pediatric patients. Pepsin/pepsinogen analysis in effusions of children, using ELISA, can be considered a reliable marker for assessment of reflux in children with OME.