32 research outputs found

    New modified poly(ester amide) resins and their uses as a binder for surface coating with different applications

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    This paper aims to prepare a new modified poly(ester amide) (PEA) resins and use it as a binder for anticorrosive and antimicrobial coatings. Design/methodology/approach New modified PEA compositions were prepared based on 4-amino-N, N-bis(2-hydroxyethyl) benzamide (AHEB) as the ingredient source of the polyol used and evaluated as vehicles for surface coating. The structure of the modifier and PEA resin was confirmed by FT-IR, H¹-NMR, MW, thermogravimetric analysis and scanning electron microscope studies. Coatings of 50±5 µm thickness were applied to the surface of glass panels and mild steel strips by means of a brush. The coating performance of the resins was evaluated using international standard test methods and involved the measurement of phyisco-mechanical properties and chemical resistance. Findings The tests carried out revealed that the modified PEA based on AHEB enhanced both phyisco-mechanical and chemical properties. Also, the resins were incorporated within primer formulations and evaluated as anti-corrosive and antimicrobial single coatings. The results illustrate that the introduction of AHEB, within the resin structure, improved the film performance and enhances the corrosion resistance and antimicrobial activity performance of PEA resins. Practical implications The modified PEA compounds can be used as binders in paint formulations to improve the chemical, physical, corrosion resistance and antimicrobial activity properties. Originality/value Modified PEA resins are cheaper and can be used to replace other more expensive binders. These modified PEA resins can compensate successfully for the presence of many the anticorrosive and antimicrobial paint formulations, and thus, lower the costs. The main advantage of these binders is that they combine the properties of both polyester and polyamide resins based on nitrogenous compound, are of lower cost and they also overcome the disadvantages of both its counterparts. Also, they can be applied in other industrial applications

    Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

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    Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

    Bioreactor for microalgal cultivation systems: strategy and development

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    Microalgae are important natural resources that can provide food, medicine, energy and various bioproducts for nutraceutical, cosmeceutical and aquaculture industries. Their production rates are superior compared to those of terrestrial crops. However, microalgae biomass production on a large scale is still a challenging problem in terms of economic and ecological viability. Microalgal cultivation system should be designed to maximize production with the least cost. Energy efficient approaches of using light, dynamic mixing to maximize use of carbon dioxide (CO2) and nutrients and selection of highly productive species are the main considerations in designing an efficient photobioreactor. In general, optimized culture conditions and biological responses are the two overarching attributes to be considered for photobioreactor design strategies. Thus, fundamental aspects of microalgae growth, such as availability of suitable light, CO2 and nutrients to each growing cell, suitable environmental parameters (including temperature and pH) and efficient removal of oxygen which otherwise would negatively impact the algal growth, should be integrated into the photobioreactor design and function. Innovations should be strategized to fully exploit the wastewaters, flue-gas, waves or solar energy to drive large outdoor microalgae cultivation systems. Cultured species should be carefully selected to match the most suitable growth parameters in different reactor systems. Factors that would decrease production such as photoinhibition, self-shading and phosphate flocculation should be nullified using appropriate technical approaches such as flashing light innovation, selective light spectrum, light-CO2 synergy and mixing dynamics. Use of predictive mathematical modelling and adoption of new technologies in novel photobioreactor design will not only increase the photosynthetic and growth rates but will also enhance the quality of microalgae composition. Optimizing the use of natural resources and industrial wastes that would otherwise harm the environment should be given emphasis in strategizing the photobioreactor mass production. To date, more research and innovation are needed since scalability and economics of microalgae cultivation using photobioreactors remain the challenges to be overcome for large-scale microalgae production

    Global variation in anastomosis and end colostomy formation following left-sided colorectal resection

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    Background End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection. Methods This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle- and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model. Results In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6·9 per cent) from low-HDI, 254 (15·5 per cent) from middle-HDI and 1268 (77·6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57·5, 40·9 and 35·4 per cent; P < 0·001) and subsequent use of end colostomy (52·2, 24·8 and 18·9 per cent; P < 0·001) in low- compared with middle- and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3·20, 95 per cent c.i. 1·35 to 7·57; P = 0·008) after risk adjustment for malignant disease (OR 2·34, 1·65 to 3·32; P < 0·001), emergency surgery (OR 4·08, 2·73 to 6·10; P < 0·001), time to operation at least 48 h (OR 1·99, 1·28 to 3·09; P = 0·002) and disease perforation (OR 4·00, 2·81 to 5·69; P < 0·001). Conclusion Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone

    Efficient Harmonic Generation in High-Q Gallium Nitride Photonic Crystal Cavities on Silicon

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    Summary form only given. Frequency conversion from the telecom range into the visible is demonstrated in suspended GaN slab photonic crystal (PhC) cavities through second harmonic generation (SHG) and third harmonic generation (THG), under continuous-wave resonant excitation. PhC cavities based on L3 and H0 designs are implemented with embedded injectors, the latter shown in Fig. 1a, enabling improved coupling to the fundamental cavity mode using far-field excitation. Q-factors as high as 2.2×10 5 near λ=1550 nm were obtained through automated optimization runs for the localized cavity modes [1], based on guided-mode expansion computations. To confirm scalability across the telecom range, two design wavelengths at 1300 nm and 1550 nm were targeted for the devices.Fabricated cavities were characterized by means of resonant scattering, to extract the unloaded Qfactors and the coupling efficiency. Record Q-factors of up to 4.1×104 and 4.4×104 were measured for the L3 and H0 cavities respectively near λ=1550 nm. For cavities that exhibited intermediate-sized injectors (theoretical external coupling efficiency of 55-60 %), experimental Q-factors were lower than the computed theoretical values by less than a factor of two. The strong enhancement in field coupling and localization in cavities with optimal combination of injector size and Q-factor has enabled efficient SHG, which achieved normalized conversion efficiency values of up to 2.4×10-3 W-1, the highest reported in GaN to date across all platforms. The emitted SHG signal was found to be delocalized due to the absence of a photonic bandgap at the second harmonic for quasi transverse-magnetic modes, and is seen in Fig. 1b to traverse the lattice of an optimized H0 cavity

    The Effect of an Education Program on School Children Oral Health in Khartoum, Sudan

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    Galal Faisal Abdulqader Abdulla Albani,1 Widad Ibrahim Abdelgadir,2,3 Amal Abdelgadir Ali Mohamed,4 Magda Yousif,5 Amna Mohammed Ali Mustafa,6 Egbal Abbashar Algmair Almkiy,7,8 Khadiga Z M Mohammed,4,9 Eman Ahmed Saad Mohamed,7 Fahad Abdullah A Alghamdi,10 Raga Gasim Ahmed,11 Manal SA Hakami,10 Niemat A Dinar,10 Amal Alsulami,2 AbdAllah Ibrahim AbdAlrahman Mudawi,12 Waled AM Ahmed10 1Department of Nursing, Faculty of Medical Sciences, Aljanad University for Science and Technology, Taiz, Yemen; 2Department of Community Health Nursing & Mental Nursing Sciences College of Nursing,Taif university, Taif, Saudi Arabia; 3Faculty of Nursing Sciences Bahri University, Sudan; 4Department of Maternal and Child Nursing Sciences College of Nursing,Taif university, Taif, Saudi Arabia; 5Nursing Department, Prince Sultan Military College of Health Sciences, Dhahran, Saudi Arabia; 6Faculty of Nursing Sciences, Jazan University, Jazan Saudi Arabia; 7Department of Nursing, Faculty of Applied Medical Sciences, Buraydah College, Buraydah, Saudi Arabia; 8Faculty of Nursing Sciences, Alneelain University, Sudan; 9Nursing Faculty, Zagazig University, Zagazig, Egypt; 10Faculty of Nursing, Al-Baha University, Al-Baha, Saudi Arabia; 11Department of Nursing, Faculty of Applied Medical Sciences, Al-Baha University, Al-Baha, Saudi Arabia; 12Oral and Dental Health Department, Faculty of Applied Medical Sciences, Al-Baha University, Al-Baha, Saudi ArabiaCorrespondence: Waled AM Ahmed; Amal Abdelgadir Ali Mohamed, Tel +966508245369; +966550367392, Email [email protected]; [email protected]: Oral health education programs have long been considered an essential part of oral health policies. This is important for reducing the risk of oral diseases through health enhancement and voluntary behavioral changes due to learning opportunities. This study aimed to evaluate the effects of school-based oral health education program on oral health in school children in Sudan.Methods: A quasi-experimental study was conducted at four governmental schools in Khartoum, Sudan, between August 2018, and March 2022. A total of 423 school children were randomly allocated into the control (n = 211) and study (n = 212) groups. An adapted questionnaire was administered to students before and after the intervention to assess their knowledge and practice of oral health. The study group participated in oral health education activities. Data were analyzed using the Statistical Package for the Social Sciences (SPSS), version 21.Results: The findings revealed that the mean knowledge at the pre-educational program was 9.3066 (SD = 3.91078) and the mean knowledge after the educational program was 21.2736 (SD = 2.13982). The scores indicated that the school children had significantly higher knowledge and practice scores after the oral health education program.Conclusion: The study concluded that education program on oral health improved students’ oral health knowledge and practices. Imposing theoretical and practical lessons on oral and dental health in school curricula can motivate students to maintain oral health care, and this improves oral health status.Keywords: education program, school children, oral health, knowledge, practice, Suda

    Immunogenicity and Safety of an Inactivated SARS-CoV-2 Vaccine: Preclinical Studies

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    Since the emergence of SARS-CoV-2 at the end of 2019, 64 candidate vaccines are in clinical development and 173 are in the pre-clinical phase. Five types of vaccines are currently approved for emergency use in many countries (Inactivated, Sinopharm; Viral-vector, Astrazeneca, and Gamaleya Research Institute; mRNA, Moderna, and BioNTech/Pfizer). The main challenge in this pandemic was the availability to produce an effective vaccine to be distributed to the world’s population in a short time. Herein, we developed a whole virus NRC-VACC-01 inactivated candidate SARS-CoV-2 vaccine and tested its safety and immunogenicity in laboratory animals. In the preclinical studies, we used four experimental animals (mice, rats, guinea pigs, and hamsters). Antibodies were detected as of week three post vaccination and continued up to week ten in the four experimental models. Safety evaluation of NRC-VACC-01 inactivated candidate vaccine in rats revealed that the vaccine was highly tolerable. By studying the effect of booster dose in the immunological profile of vaccinated mice, we observed an increase in neutralizing antibody titers after the booster shot, thus a booster dose was highly recommended after week three or four. Challenge infection of hamsters showed that the vaccinated group had lower morbidity and shedding than the control group. A phase I clinical trial will be performed to assess safety in human subjects

    Immunogenicity and Safety of an Inactivated SARS-CoV-2 Vaccine: Preclinical Studies

    No full text
    Since the emergence of SARS-CoV-2 at the end of 2019, 64 candidate vaccines are in clinical development and 173 are in the pre-clinical phase. Five types of vaccines are currently approved for emergency use in many countries (Inactivated, Sinopharm; Viral-vector, Astrazeneca, and Gamaleya Research Institute; mRNA, Moderna, and BioNTech/Pfizer). The main challenge in this pandemic was the availability to produce an effective vaccine to be distributed to the world’s population in a short time. Herein, we developed a whole virus NRC-VACC-01 inactivated candidate SARS-CoV-2 vaccine and tested its safety and immunogenicity in laboratory animals. In the preclinical studies, we used four experimental animals (mice, rats, guinea pigs, and hamsters). Antibodies were detected as of week three post vaccination and continued up to week ten in the four experimental models. Safety evaluation of NRC-VACC-01 inactivated candidate vaccine in rats revealed that the vaccine was highly tolerable. By studying the effect of booster dose in the immunological profile of vaccinated mice, we observed an increase in neutralizing antibody titers after the booster shot, thus a booster dose was highly recommended after week three or four. Challenge infection of hamsters showed that the vaccinated group had lower morbidity and shedding than the control group. A phase I clinical trial will be performed to assess safety in human subjects
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