27 research outputs found
Exploring Safety Aspects in Dental School Clinics Including Droplet Infection Prevention
BACKGROUND: Health-care safety focuses on improving patient’s and worker’s safety in a safe working clinics’ environment and prevent infection transmission including droplet infections as seasonal influenza and novel coronavirus (COVID-19). Dental health-care personnel (DHCP) are the target of safety measures and are themselves responsible for elimination of preventable harm. Dental schools are expected to demonstrate the model for quality safe care.
AIM: This study aims to achieve high-quality safe dental care at dental clinics, Faculty of Dentistry, Cairo University.
METHODS: A cross-sectional survey study was conducted at two Dental Outpatient Clinics, Cairo University. Disk review of policies, observation checklists for practices and awareness questionnaires of DHCP were used.
RESULTS: DHCP showed good awareness for most of infection control (IC) and X-ray safety items. However, there are no policies or procedures to control droplet infections in the clinics. The clinics were closed in the current COVID-19 pandemic. There were poor patient safety practices, hand hygiene compliance, and personal protective equipment (PPE) use except for protecting clothes and disposable gloves. Students showed better compliance for patient safety guidelines. Other safety policies were poorly communicated.
CONCLUSION: There should be preparedness plan to deal with any droplet infection outbreak, epidemic or pandemic as COVID-19 in all dental settings. There is a need to initiate dental safety unit in dental schools to implement, communicate, train, and supervise all dental safety practices including infection control
3D porous polymers for selective removal of CO2 and H2 storage: experimental and computational studies
In this article, newly designed 3D porous polymers with tuned porosity were synthesized by the polycondensation of tetrakis (4-aminophenyl) methane with pyrrole to form M1 polymer and with phenazine to form M2 polymer. The polymerization reaction used p-formaldehyde as a linker and nitric acid as a catalyst. The newly designed 3D porous polymers showed permanent porosity with a BET surface area of 575 m2/g for M1 and 389 m2/g for M2. The structure and thermal stability were investigated by solid 13C-NMR spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA). The performance of the synthesized polymers toward CO2 and H2 was evaluated, demonstrating adsorption capacities of 1.85 mmol/g and 2.10 mmol/g for CO2 by M1 and M2, respectively. The importance of the synthesized polymers lies in their selectivity for CO2 capture, with CO2/N2 selectivity of 43 and 51 for M1 and M2, respectively. M1 and M2 polymers showed their capability for hydrogen storage with a capacity of 66 cm3/g (0.6 wt%) and 87 cm3/g (0.8 wt%), respectively, at 1 bar and 77 K. Molecular dynamics (MD) simulations using the grand canonical Monte Carlo (GCMC) method revealed the presence of considerable microporosity on M2, making it highly selective to CO2. The exceptional removal capabilities, combined with the high thermal stability and microporosity, enable M2 to be a potential material for flue gas purification and hydrogen storage
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Treating with Birds: The Insights of Two Mamluk Sources about the Medical Benefits of Birds
Two important Mamluk sources that discuss animals, including birds, are the encyclopedic Masālik al-abṣār fī mamālik al-amṣār by al-ʿUmarī and al-Damīrī’s zoology book Ḥayāt al-ḥayawān. Although neither is a medical text, they both devote protracted parts to the medical benefits and pharmaceutical uses of birds. Since medicine, pharmacy, and dietetics were connected sciences correlated with human physical well-being and health, discussing birds primarily used as food necessitated the elucidation of their medical benefits and how to use them for treatment. Furthermore, the sources explained the usage of their parts, extracts, products, and droppings in both formal and folk medicine. This study explores the medical benefits of birds as presented in those two Mamluk sources to investigate the importance of substances of animal origin in the preparation of simple and compound medicines and folk remedies. Such an investigation can also shed light on other intellectual and social aspects of Mamluk society in Egypt
Painless aortic dissection presented with acute paraplegia
Acute aortic dissection is considered a potentially fatal condition. Neurologic manifestations such as paraplegia are quite rare. We report a case of acute paraplegia in a hypertensive smoker chronic obstructive lung disease patient. Transthoracic echocardiography revealed a dissection flap starting at the aortic annulus and extending to the descending thoracic aorta. Computed tomographic aortography confirmed the diagnosis with a dissection flap extended from the aortic annulus to the entire distal aorta. The patient was referred to another specialized cardiothoracic center, but unfortunately, he died during the surgery
Effect of Different Surface Treatments on Bond Strength to Tetragonal and Cubic Zirconia
Background: Dental zirconia has been widely used due to its superior mechanical properties. However, traditional etching techniques and surface treatments are generally ineffective on zirconia surfaces due to its inertness and lack of a silica phase. Hence, various surface treatments are applied to improve bonding to zirconia.
Objectives: The aim of this study was to evaluate the effect of three different surface treatments: low pressure air borne particle abrasion, selective infiltration etching and fusion sputtering on bond strength to both Tetragonal zirconia and Cubic zirconia.
Materials and Methods: Ninety two specimens of zirconia were used in this study. Two of the specimens were investigated for surface analysis and ninety specimens was divided into 2 groups according to type of zirconia used cubic zirconia (Bruxir anterior) and tetragonal zirconia (Cercon), specimens of each group will be divided into 3 subgroups according to type of surface treatments low pressure airborne-particle abrasion, selective infiltration etching and fusion sputtering, then will be divided into 3 divisions according to time interval as immediate, thermocycling and water storage.
Results: Statistical analysis of data revealed significant differences in surface treatments on shear bond strength (F=124, P
Conclusion: Within limitations of this study, Selective infiltration etching produced the highest shear bond strength compared to other surface treatment. Selective infiltration etching is a promising surface treatment for both cubic and tetragonal zirconia. Both thermocycling and water storage significantly affected the shear bond strength of both cubic and tetragonal zirconia
A Ovsynch Produced Larger Follicles and Corpora Lutea of Lower Blood Flow associated Lower Ovarian and Uterine Blood Flows, Estradiol and Nitric Oxide in Cows : Ovsynch ovarian response and blood flow of cows
The use of ovsynch and its modifications for synchronizing estrous cycle and ovulation in ruminants is widely used with lowered conceptions rates. This study aimed to investigate the follicular (F1) and the corpus luteum (CL) hemodynamics, ovarian (OvA) and uterine arteries (UtA) blood flow volumes (BFV) and dynamics associated with the circulating estradiol (E2), progesterone (P4), glucose and nitric oxide (NO) in cows treated with the ovsynch protocol. Eight Friesian cows underwent trans-rectal Doppler scanning and blood sampling each other day throughout two successive non-treated (Spontaneous) and two treated successive estrous cycles (ovsynch). The results revealed that the existed dominant follicles (F1) area, antrum area, color area, and the CL area and the color area on the ovaries declined following the first dose of the gonadotropin-releasing hormone (GnRH, Day-11) till Day -5 then another dominant follicle started growth and reached ovulation (Day 0). Ovsynch pre-ovulatory phase (Day-5 to 0) had more (P<0.01) small, medium, and total follicles. The ovsynch F1 (P=0.001) and the CL (P=0.006) had higher areas but lower color areas percent. The ovsynch increased ipsi-lateral OvA pulsatility index (PI) that associated decreased diameter and time average mean velocity (TAMV) and blood flow volume except Day 6 (BFV, P<0.05). The ovsynch improved (P<0.01) the ipsilateral UtA PI but lowered its diameter, peak systolic velocity (PSV), TAMV, and BFV except Day 10. Ovsynch ovulation was characterized by low E2, NO, and high glucose but the late luteal phase had high (P<0.001) P4 and glucose with low E2. In conclusion, the decreased follicle and luteal vascularization with lowered uterine blood flow and estradiol may adversely affect the quality of the oocyte and the decreased progesterone from Day 7 till Day 10 and the ipsilateral uterine artery BFV may not support the implantation and disturb the maintenance of the embryo after timed insemination
Optimization of tannase production by Aspergillus glaucus in solid-state fermentation of black tea waste
Abstract Tannases are valuable industrial enzymes used in food, pharmaceutical, cosmetic, leather manufacture and in environmental biotechnology. In this study, 15 fungal isolates were obtained from Egyptian cultivated soil and marine samples. The isolated fungi were qualitatively and quantitatively screened for their abilities to produce tannase. The selected fungal isolate NRC8 giving highest tannase activity was identified by molecular technique (18S rRNA) as Aspergillus glaucus. Among different tannin-containing wastes tested, the black tea waste was the best substrate for tannase production by Aspergillus glaucus in solid-state fermentation (SSF). Optimization of the different process parameters required for maximum enzyme production was carried out to design a suitable SSF process. Maximal tannase production was achieved with moisture content of 75%, an inoculums size of 6 × 108 spore/ml and sodium nitrate 0.2% (pH of 5.0) at 30 °C after 5 days of incubation. Box–Behnken experiment was designed to get a quadratic model for further optimization studies. Four-factor response-surface method with 27 runs was prepared using independent parameters including (moisture content %, initial pH, substrate concentration (g) and sodium nitrate concentration (g) for tannase model. The F- and P-values of the model were 4.30 and 0.002, respectively, which implied that the model is significant. In addition, the lack-of-fit was 1040.37 which indicates the same significance relative to the pure error. A. glaucus tannase was evaluated by the efficiency of conversion of tannic acid to gallic acid. Moreover, production of gallic acid from SSF process of A. glaucus using black tea waste was found to be 38.27 mg/ml. The best bioconversion efficiency was achieved at 40 °C with tannic acid concentration up to 200 g/L. Graphical Abstrac
SYNTHESIS AND BIOLOGICAL EVALUATION OF NOVEL COUMARIN DERIVATIVES AS POTENTIAL ANTIMICROBIAL AGENTS
Objective: Synthesize new series of 7-hydroxy-4-methylcoumarin and 7-alkoxy-4-methylcoumarin derivatives featuring thiosemicarbazone or thiazolidin-4-one moieties and to evaluate their antimicrobial activity against two strains of Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), two Gram-negative bacteria (Escherichia Coli and Pseudomonas aeruginosa), and Candida albicans.Methods: Preparation of the new coumarin derivatives was done by adopting Pechmann condensation and attaching different isothiocyanates to give coumarin-thiosemicarbazone hybrids. Thiosemicarbazones were cyclized into thiazolidine-4-ones using chloroacetic acid or diethyl bromo malonate.Results: Compounds VIb, Xb, XIVb, and XVc gave the highest inhibition zones (>20 mm) against Staphylococcus aureus. Their MIC (minimum inhibitory concentration) values ranging from 0.19-0.36 µg/ml were better than the reference drug tobramycin with MIC= 2µg/ml.Conclusion: The newly synthesized compounds with the 7-hydroxyl group showed better antimicrobial activity than those with the 7-alkoxy groups.Keywords: Coumarin, Thiosemicarbazones, Thiazolidin-4-ones, Antimicrobial activit