122 research outputs found

    Common Fixed Point Theorems for Weak Contraction Conditions of Integral Type

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    In this paper we shall establish two common fixed point theorems for a contractive condition and A-contraction mappings of integral type which improve and extend the results of P.B. Prajapati, R. Bhardwaj, M. O. Olatinwo and many others.Keywords: Common fixed point, general contractive mapps of integral type, weak contraction, metric spaces

    Hydraulic Jump in Circular Open Channels with Mild Slope

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    A hydraulic jump is a well-known transitionalphenomenon from supercritical to subcritical flows withundulations of water-surface. In this transition, the water flowhas a high-velocity, water surface rises abruptly, surface rollersare formed, intense mixing occurs, the air is entrained, and alarge amount of energy is dissipated. In the present studycharacteristics of the hydraulic jumps in circular open channelswith a mild sloped have been discussed under a wide range ofexperimental conditions. The study aims to determine the effectof the channel’s mild slope on the characteristics of thehydraulic jumps with circular channels. A theoretical study hasbeen done and led to obtaining equations that can be used to getspecific force for the hydraulic jump that occurred in circularopen channels. A theoretical study is based on usingmomentum, and Froude’s number equations. An experimentalstudy has been investigated using Laboratory 40 experimentalruns in circular section flume for eight different dischargesranged from 3.92 to 12.07 l/sec were given with mild slopeequals 0.000833. In total, the experiments were conducted overa range of Froude numbers from 1.78 to 8.87. The experimentalworks concluded some dimensionless curves and new usefulformulas to get the length of the jump, energy dissipated andefficiency. The conjugated depth ratio is determined and plottedversus the upstream Froude number, downstream Froudenumber, head loss, and efficiency for different values of criticaldepths. The resulting graphs and equations of the present studyare readily applicable for a design for the hydraulic jumps inthe circular open channels with mild slope

    Physostigmine: A Plant Alkaloid Isolated from Physostigma venenosum: A Review on Pharmacokinetics, Pharmacological and Toxicological Activities

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    Medicinal plants have been documented as an important source for discovering new pharmaceutical molecules that have been used to treat serious diseases. Strikingly, previous reports stated that natural products and their derived compounds exhibit lesser side effects and improved efficacy than other synthetic counterparts. Physostigmine, a parasympathomimetic plant alkaloid isolated from the West African perennial shrub Physostigma venenosum, it shows a narrow therapeutic index and a short life span, despite its ability to penetrate the blood-brain barrier (BBB). It is a widely known reversible butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE) inhibitor and has been documented to treat various ailments such as Alzheimer’s disease. Pharmacologically, physostigmine was first reported as an antidote for atropine scopolamine and belladonna alkaloids toxicity. Recently, it has been documented as a therapy for treating several ailments including glaucoma, myasthenia gravis and the intoxication caused by tricyclic antidepressant overdoses, anti-histamines, antipsychotics, and benzodiazepines. Physostigmine has been reported to be absorbed from the gastrointestinal tract and showed short half-life, as, after the oral administration of 2 mg of physostigmine salicylate, the peak plasma concentration reached to 30 minutes. This review examines the biological activities, pharmacokinetics, and toxicity of physostigmine extracted from P. venenosum. Keywords: Physostigma venenosum, Physostigmine, pharmacological activities, acetylcholinesterase and butyrylcholinesterase inhibitor

    Vitamin D Status in Neonates with Hyperbilirubinemia

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    Background: Physiological Jaundiceis more common in neonates. While causes such as incompatibility of blood groups or polycythemia can be easily identified, most are still undiagnosed. Phototherapy is an effective way to reduce the accumulation of bilirubin. Vitamin D is a fat-soluble vitamin that plays an important role in bone remodeling. It is also considered a steroid hormone, plays an important role in the main function of various organ systems, and can be a risk factor for changing the risk of many chronic diseases. There is a link between vitamin D and jaundice. Newborns with hyperbilirubinemia have low serum vitamin D levels. Conclusion: There is an association between indirect hyperbilirubinaemia and vitamin D levels in neonates with jaundice at the level necessary for phototherapy

    Radiological Hazard Evaluation of Some Egyptian Magmatic Rocks Used as Ornamental Stone: Petrography and Natural Radioactivity

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    Magmatic rocks represent one of the most significant rocks due to their abundance, durability and appearance; they can be used as ornamental stones in the construction of dwellings. The current study is concerned with the detailed petrography and natural radioactivity of seven magmatic rocks. All are commercial granitic rocks and are identified as black Aswan, Nero Aswan, white Halayeb, Karnak, Verdi, red Hurghada and red Aswan. Their respective mineralogical com-positions are classified as porpheritic granodiorite, granodiorite, tonalite, monzogranite, syenogran-ite, monzogranite and syenogranite. A total of nineteen samples were prepared from these seven rock types in order to assess their suitability as ornamental stones. Concentrations of 226Ra, 232Th and 40K radionuclides were measured using NaI (Tl) scintillation gamma-ray spectrometry. Among the studied magmatic rocks, white Halayeb had the lowest average values of226Ra (15.7 Bq/kg),232Th (4.71 Bq/kg) and40K (~292 Bq/kg), all below the UNSCEAR reported average world values or rec-ommended reference limits. In contrast, the other granitic rocks have higher values than the recom-mended limit. Except for the absorbed dose rate, other radiological hazard parameters including radium equivalent activity, annual effective dose equivalent, external, and internal hazard indices reflect that the White Halyeb rocks are favorable for use as ornamental stone in the construction of luxurious and high-demand residential buildings. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: We deeply acknowledge Taif University for supporting the researchers through Taif University Researchers Supporting Project number (TURSP-2020/287), Taif University, Taif, Saudi Arabia

    Knowledge of dental academics about the COVID-19 pandemic: a multi-country online survey.

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    BACKGROUND: COVID-19 is a global pandemic affecting all aspects of life in all countries. We assessed COVID-19 knowledge and associated factors among dental academics in 26 countries. METHODS: We invited dental academics to participate in a cross-sectional, multi-country, online survey from March to April 2020. The survey collected data on knowledge of COVID-19 regarding the mode of transmission, symptoms, diagnosis, treatment, protection, and dental treatment precautions as well as participants' background variables. Multilevel linear models were used to assess the association between dental academics' knowledge of COVID-19 and individual level (personal and professional) and country-level (number of COVID-19 cases/ million population) factors accounting for random variation among countries. RESULTS: Two thousand forty-five academics participated in the survey (response rate 14.3%, with 54.7% female and 67% younger than 46 years of age). The mean (SD) knowledge percent score was 73.2 (11.2) %, and the score of knowledge of symptoms was significantly lower than the score of knowledge of diagnostic methods (53.1 and 85.4%, P <  0.0001). Knowledge score was significantly higher among those living with a partner/spouse than among those living alone (regression coefficient (B) = 0.48); higher among those with PhD degrees than among those with Bachelor of Dental Science degrees (B = 0.48); higher among those seeing 21 to 30 patients daily than among those seeing no patients (B = 0.65); and higher among those from countries with a higher number of COVID-19 cases/million population (B = 0.0007). CONCLUSIONS: Dental academics had poorer knowledge of COVID-19 symptoms than of COVID-19 diagnostic methods. Living arrangements, academic degrees, patient load, and magnitude of the epidemic in the country were associated with COVD-19 knowledge among dental academics. Training of dental academics on COVID-19 can be designed using these findings to recruit those with the greatest need

    Knowledge of dental academics about the COVID-19 pandemic: a multi-country online survey

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    Background: COVID-19 is a global pandemic affecting all aspects of life in all countries. We assessed COVID-19 knowledge and associated factors among dental academics in 26 countries. Methods: We invited dental academics to participate in a cross-sectional, multi-country, online survey from March to April 2020. The survey collected data on knowledge of COVID-19 regarding the mode of transmission, symptoms, diagnosis, treatment, protection, and dental treatment precautions as well as participants’ background variables. Multilevel linear models were used to assess the association between dental academics’ knowledge of COVID-19 and individual level (personal and professional) and country-level (number of COVID-19 cases/ million population) factors accounting for random variation among countries. Results: Two thousand forty-five academics participated in the survey (response rate 14.3%, with 54.7% female and 67% younger than 46 years of age). The mean (SD) knowledge percent score was 73.2 (11.2) %, and the score of knowledge of symptoms was significantly lower than the score of knowledge of diagnostic methods (53.1 and 85.4%, P &lt; 0.0001). Knowledge score was significantly higher among those living with a partner/spouse than among those living alone (regression coefficient (B) = 0.48); higher among those with PhD degrees than among those with Bachelor of Dental Science degrees (B = 0.48); higher among those seeing 21 to 30 patients daily than among those seeing no patients (B = 0.65); and higher among those from countries with a higher number of COVID-19 cases/million population (B = 0.0007). Conclusions: Dental academics had poorer knowledge of COVID-19 symptoms than of COVID-19 diagnostic methods. Living arrangements, academic degrees, patient load, and magnitude of the epidemic in the country were associated with COVD-19 knowledge among dental academics. Training of dental academics on COVID-19 can be designed using these findings to recruit those with the greatest need

    Perceived preparedness of dental academic institutions to cope with the COVID-19 pandemic: a multi-country survey

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    Dental academic institutions are affected by COVID-19. We assessed the perceived COVID19 preparedness of these institutions and the characteristics of institutions with greater perceived preparedness. An international cross-sectional survey of dental academics was conducted from March to August 2020 to assess academics’ and institutional attributes, perceived preparedness, and availability of infection prevention and control (IPC) equipment. Principal component analysis (PCA) identified perceived preparedness components. Multilevel linear regression analysis assessed the association between perceived preparedness and fixed effect factors (academics’ and institutions’ attributes) with countries as random effect variable. Of the 1820 dental academics from 28 countries, 78.4% worked in public institutions and 75.2% reported temporary closure. PCA showed five components: clinic apparel, measures before and after patient care, institutional policies, and availability of IPC equipment. Significantly less perceived preparedness was reported in lower-middle income (LMICs) (B = −1.31, p = 0.006) and upper-middle income (UMICs) (B = −0.98, p = 0.02) countries than in high-income countries (HICs), in teaching only (B = −0.55, p &lt; 0.0001) and in research only (B = −1.22, p = 0.003) than teaching and research institutions and in institutions receiving ≤100 patients daily than those receiving &gt;100 patients (B = −0.38, p &lt; 0.0001). More perceived preparedness was reported by academics with administrative roles (B = 0.59, p &lt; 0.0001). Academics from low-income countries (LICs) and LMICs reported less availability of clinic apparel, IPC equipment, measures before patient care, and institutional policies but more measures during patient care. There was greater perceived preparedness in HICs and institutions with greater involvement in teaching, research, and patient care
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