450 research outputs found

    Self-Emulsifying Drug Delivery Systems: Easy to Prepare Multifunctional Vectors for Efficient Oral Delivery

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    Self-emulsifying drug delivery systems (SEDDS) have been mainly investigated to enhance the oral bioavailability of drugs belonging to class II of the Biopharmaceutics Classification System. However, in the past few years, they have shown promising outcomes in the oral delivery of various types of therapeutic agents. In this chapter, we discuss the recent progress in the application of SEDDS for oral delivery of protein therapeutics and genetic materials. The role of SEDDS in enhancing the oral bioavailability of P-glycoprotein and cytochrome P450 3A4 substrate drugs is also highlighted. Also, we discuss the most critical evaluation criteria of SEDDS. Additionally, we summarize various solidification techniques employed to transform liquid SEDDS to the more stable solid self-emulsifying drug delivery systems (s-SEDDS) that are associated with high patient compliance. This chapter provides a comprehensive approach to develop high utility SEDDS and their further transformation into s-SEDDS

    Isolation and identification of bacterial strains from apple flowers in Trentino and their evaluation as biocontrol agents of Erwinia amylovora

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    Fire blight caused by Erwinia amylovora (Ea) represents a great threat to apple and pear production worldwide. For instance, the outbreak of fire blight occurred in Trentino caused a relevant reduction of crop yield in 2020. Since Ea can spread rapidly in the environment, it is difficult to manage this devastating phytopathogenic bacterium. It is now widely accepted that apple flowers may harbor bacterial taxa that might hinder the ability of Ea to colonize apple flower. Based on this body of knowledge, we aimed at investigating the microbiota of apple flowers to select new potential biocontrol agents active against Ea. Flowers of Malus domestica cv. Golden Delicious from Trentino apple orchards were sampled at the ‘Baloon stage’ and surface sterilised to isolate only bacteria residing within the flowers. Bacterial isolates were initially selected on R2A dishes according to their colony morphology and subsequently identified through 16S rRNA gene sequencing. The phylogenetic analysis showed the bacterial isolates mainly belonged to the Enterobacteriaceae, Pseudomonadaceae, and Microbacteriaceae families. One member of each bacterial family was selected and tested against Ea both on newly open apple flowers and on pear slices. Preliminary results showed some of these strains might have a significant effect on the control of Ea. In particular, Pantoea agglomerans and Curtobacterium flaccumfaciens strains showed the highest efficacy. In the future, we will carry out further experiments to investigate and understand the modes of action of these bacterial strains

    Adsorption Refrigeration Technologies

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    This chapter introduces a comprehensive overview about the principles, challenges and applications of adsorption refrigeration systems (ARSs), as a promising sustainable solution for many of cooling and heating applications. In addition to the features and the basics of ARSs, the following topics have been covered such as characteristics of working pairs, trends in improving the heat and mass transfer of the adsorber; advanced adsorption cycles and performance and operational data of some adsorption refrigeration applications. In some details, the operating range and the performance of ARSs are greatly affected by the employed working adsorbent/refrigerant pairs. Therefore, the study, development and optimum selection of adsorbent/refrigerant pairs, particularly the composite adsorbents, can lead to improving the performance and reliability of ARSs. Regarding the enhancement of heat and mass transfer in the adsorbent bed, two methods are commonly used: one is the development of adsorbents through different coating technologies or new materials such as metal-organic frameworks, and the second is the optimization of the adsorber geometrical parameters and cycle modes. Finally, a brief on some adsorption chillers applications have started to find their share in markets and driven by solar or waste heats

    Frequency of abdominal aortic aneurysm in persons who have been examined with ultrasound at Kasr Al-Ainy Hospitals: a single center pilot study

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    Introduction: To know frequency of abdominal aortic aneurysm (AAA) using ultrasound and clarify associated risk factors in 1000 Egyptians. Material and methods: Prospective study. 1000 patients aged 50 years or more (mean: 57.97 ± [7.68]) were examined by B-mode ultrasound at our radiology department to measure suprarenal maximum diameter of the abdominal aorta (wall to wall measurement) and to identify the occurrence of AAA (aneurysms were defined as 1.5 times the mean diameter). Demographic data and risk factors were also noted. Results: Mean aortic diameter in study population was 18.9 ± (3.2) mm. AAA diameter was 28.3 mm. Frequency of AAA was 1.5%. AAA prevalence: 2.35% in males versus 0.75% in females. Prevalence of AAA in different age groups: < 60 years (n = 653), 60–70 (n = 282), > 70 years (n = 65) was 6 (0.9%), 6 (2.1%), 3 (4.6%) respectively. Patients with AAA were older (P < 0.001), more often male (P < 0.001), smokers (P < 0.001). Conclusion: Study showed that mean aortic diameter was 18.9 mm and AAA is present in 1.5% of the study population which was less than that seen in previously conducted studies in other countries

    A high-speed microturbine PMA-SYnRg emulation using power hardware-in-the-loop for wind energy conversion systems

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    In this paper, a high-speed microturbine (MT) permanent magnet assisted synchronous reluctance generator (PMa-SynRG) real-time emulation based on linear impedance regulator (LIR) using power hardware-in-the-loop (PHIL) for wind energy generation tests is presented. The LIR is designed without any feedback control loop for reshaping the s-domain performances of the current filter along with the converter inside the PMa-SynRG emulated system. The PHIL platform not only provides a method for eliminating the high cost of using real renewable energy hardware but also it enables the developers to create new, rapid, and reliable controllers for renewable energy testing. This platform can be used in investigating the performance of energy system under various conditions even if the generator prototype is not yet developed or unavailable. PMa-SynRG mathematical model is emulated in the real-time using PHIL platform while the output voltage of the proposed emulator imitates the generated voltage through the simulated model. In addition, a voltage source converter is employed as a voltage amplifier for imitating the PMa-SynRG performance when supplying nonlinear/linear loads. In this paper, the proportional-integral resonant (PIR) controller is utilized at the voltage control loop for tracking the distorted output reference signal voltage. In order to investigate the performance of the proposed PMa-SynRG emulator, it has been simulated and compared with MATLAB/SIMULINK environment

    CPS Attacks Mitigation Approaches on Power Electronic Systems with Security Challenges for Smart Grid Applications: A Review

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    This paper presents an inclusive review of the cyber-physical (CP) attacks, vulnerabilities, mitigation approaches on the power electronics and the security challenges for the smart grid applications. With the rapid evolution of the physical systems in the power electronics applications for interfacing renewable energy sources that incorporate with cyber frameworks, the cyber threats have a critical impact on the smart grid performance. Due to the existence of electronic devices in the smart grid applications, which are interconnected through communication networks, these networks may be subjected to severe cyber-attacks by hackers. If this occurs, the digital controllers can be physically isolated from the control loop. Therefore, the cyber-physical systems (CPSs) in the power electronic systems employed in the smart grid need special treatment and security. In this paper, an overview of the power electronics systems security on the networked smart grid from the CP perception, as well as then emphases on prominent CP attack patterns with substantial influence on the power electronics components operation along with analogous defense solutions. Furthermore, appraisal of the CPS threats attacks mitigation approaches, and encounters along the smart grid applications are discussed. Finally, the paper concludes with upcoming trends and challenges in CP security in the smart grid applications

    Utilization of Some Fruits and Vegetables By-Products to Produce High Dietary Fiber Jam

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    The present study aimed to investigate the chemical composition, antioxidant activity, total phenolic compounds and ?-carotene of carrot peels, apple pomace, banana peels and mandarin peels and their quality in preparing jam. Mandarin and banana peels characterized by its higher crude fiber (12.16 and 5.25%) and vitamin C (68 and 16.6 mg/100g) compared to carrot peels (3.91%) and apple pomace (3.65%). Banana peels contained higher amount of magnesium, potassium, calcium and iron compared to other peels samples. Therefore, jam of banana peels characterized by its higher content in magnesium (758 mg/100g), potassium (779 mg/100g), calcium (191 mg/100g) and iron (59.15 mg/100g). Jam of apple pomace characterized by its higher phosphorus contents (220 mg/100g) followed by jam of banana peels (138 mg/100g), mandarin peels (128 mg/100g) and carrot peels (53 mg/100g). Jam of carrot peels characterized by its higher phenolics content as gallic acid equivalent (87.4 mg/100g) followed by jams of apple pomace (82.5 mg/100g), banana peels (42.7 mg/100g) and mandarin peels (34.6 mg/100g). The same trend was observed in total flavonoids as catechen equivalent (mg CAT/100g) in jams of carrot peels, apple pomace, banana peels and mandarin peels, where they were 35.9, 30.1, 23.5 and 21.7, respectively. Furthermore, jam of carrot peels had higher antioxidant activity, where its DPPH radical, had lower DPPH based IC50 (1.8 ?g/ml) while jam of apple pomace, banana peels and mandarin peels had higher DPPH based IC50 reached to 2.04, 2.21 and 3.34 µg/ml, respectively. The same trend was observed for the ?-carotene radical in tested jam samples. Hunter color parameter showed that jam of mandarin peels had highest lightness (L* = 39.8), followed by jam of carrot peels (29.46), apple pomace (18.27) and banana peels (15.19). Therefore, jam of banana peels was darker than other tested peels samples. Sensory evaluation showed that jam of apple pomace characterized by its higher taste and odor, followed by jam of mandarin peels, banana peels and carrot peels. Color of tested jam of carrot, banana or mandarin peels was darker than apple pomace jam. Also, jam of apple pomace gave higher scores in appearance and overall acceptability. Keywords: Jam – Peels – antioxidant activity – Total phenolics– Total Flavonoid

    Transfer deep learning approach for detecting coronavirus disease in X-ray images

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    Currently, the whole world is fighting a very dangerous and infectious disease caused by the novel coronavirus, called COVID-19. The COVID-19 is rapidly spreading around the world due to its high infection rate. Therefore, early discovery of COVID-19 is crucial to better treat the infected person as well as to slow down the spread of this virus. However, the current solution for detecting COVID-19 cases including the PCR test, CT images, epidemiologically history, and clinical symptoms suffer from high false positive. To overcome this problem, we have developed a novel transfer deep learning approach for detecting COVID-19 based on x-ray images. Our approach helps medical staff in determining if a patient is normal, has COVID-19, or other pneumonia. Our approach relies on pre-trained models including Inception-V3, Xception, and MobileNet to perform two tasks: i) binary classification to determine if a person infected with COVID-19 or not and ii) a multi-task classification problem to distinguish normal, COVID-19, and pneumonia cases. Our experimental results on a large dataset show that the F1-score is 100% in the first task and 97.66 in the second task

    Influence of Different Decontamination Approaches on Bone Substitute Adhesion to Peri-Implantitis Affected Implant Surfaces: An SEM Proof of Principle Study

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    Background: During healing, clot blended graft materials may retract away from implant surfaces creating microgaps that compromise re-osseointegration. The present study aimed to evaluate different surface decontamination materials’ effect on adhesion of the graft materials to peri-implantitis affected parts, a factor that can resist clot blended graft retraction improving re-osseointegration. Methods: Eighteen peri-implantitis affected implants diagnosed as hopeless and designated for removal contributed in this prospective, masked trial. Samples were randomly distributed into three groups, each of six implants. Group one (G1) was coated with hydroxyapatite of a micro particle size of 250 to 1000 µm after saline surface decontamination for two minutes. Group two (G2) peri-implantitis affected parts were treated with the graft material following two minutes of chlorhexidine gluconate 0.12% (CHX) surface treatment. Group three (G3) implants were coated with the graft material after citric acid (CA) (pH = 1) surface conditioning for two minutes. Implants in all groups were agitated in phosphate-buffered saline (PBS) by using an automatic tissue processor agitator for three minutes. Implants were prepared for surface scanning evaluation. Results: Scanning electron microscopy (SEM) observation of G1 saline treated control implants were devoid of bone particles adherent to peri-implantitis affected surfaces. The surface area covered by grafted particles in G2 was statistically higher than that of G1 (P<0.01). Group three (CA-treated) showed nearly complete coverage of peri-implantitis affected parts by the graft material covering 88.8% of examined surface areas which was statistically higher than that of G2 (P<0.05). Conclusion: Citric acid implant surface conditioning could improve implant re-osseointegration through enhancement of the graft adhesion to the implant surface. Smear layer barrier effect seemed to be the most important factor that compromised graft adhesion to preri-implantitis affected parts of the implant surfaces
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