363 research outputs found
pH-Sensitive nanoparticles containing 5-fluorouracil and leucovorin as an improved anti-cancer option for colon cancer
Parenteral administration of chemotherapeutic drugs, 5-fluorouracil (5-FU) and leucovorin (LV), is commonly used to treat large bowel carcinomas such as colon cancer (CC) and colorectal carcinoma (CRC). Our study aims to design a novel nanoparticulate drug-delivery vehicle for oral use capable of colon-specific release. A modified double-emulsion solvent evaporation method was used in the preparation of pH-responsive Eudargit S100 polymeric nanoparticles, loaded with 5-FU/LV combination (5-FU/LV-loaded Eudargit S100 NPs). Our optimized drug-loaded NP showed a pH-responsive drug release and exhibited significantly more cytotoxic actions in cancer-cell lines than free drugs. These findings open the way for conducting clinical trials for colon malignancies treated with nanoparticles
Amenability of heap leaching technology on uranium extraction from Gattar and El Missikat area, Eastern Desert, Egypt: A kinetic approach
Studies of uranium heap leaching from different uranium mineralization situated in Eastern Desert of Egypt was investigated via batch experiments, followed by its optimum condition applicationon column percolationtests.The optimum process operating parameters were implemented on large column scale in order to make more condition control and evaluate the time and reagents needed in the large scale. The results show thatleaching efficiency of GIIattained about 78.3% with 34kg/ton acid consumption in a 44 days period, while leaching efficiency of El-Missikat attained about 86.6% with 28kg/ton acid consumption in a 40 days period.Kinetics reaction models of column tests have been investigated to optimize the column leaching behavior. Based on the leaching results of two mineralized samples, the rate of the uranium metal dissolution is controlled by the chemical reaction and the diffusion reaction but diffusion reaction control was more predominate than a chemical reaction control
New Algorithm for Drawings of 3-Planar Graphs
Graphs arise in a natural way in many applications, together with the need to be drawn. Except for very small instances, drawing a graph by hand becomes a very complex task, which must be performed by automatic tools. The field of graph drawing is concerned with finding algorithms to draw graph in an aesthetically pleasant way, based upon a certain number of aesthetic criteria that define what a good drawing, (synonyms: diagrams, pictures, layouts), of a graph should be. This problem can be found in many such as in the computer networks, data networks, class inter-relationship diagrams in object oriented databases and object oriented programs, visual programming interfaces, database design systems, software engineering…etc. Given a plane graph G, we wish to find a drawing of G in the plane such that the vertices of G are represented as grid points, and the edges are represented as straight-line segments between their endpoints without any edge-intersection. Such drawings are called planar straight-line drawings of G. An additional objective is to minimize the area of the rectangular grid in which G is drawn. In this paper we introduce a new algorithms that finds an embedding of 3-planar graph. Keywords: 3- Planar Graph; Graph Drawing; drawing on grid
Kemijski sastav sojeva plijesni Monascus ruber
Chemical profile of Monascus ruber strains has been studied using gas chromatography-mass spectrometry (GC/MS) analysis. The colour intensity of the red pigment and secondary metabolic products of two M. ruber strains (AUMC 4066 and AUMC 5705) cultivated on ten different media were also studied. Metabolic products can be classified into four categories: anticholesterol, anticancer, food colouring, and essential fatty acids necessary for human health. Using GC/MS, the following 88 metabolic products were detected: butyric acid and its derivatives (25 products), other fatty acids and their derivatives (19 products), pyran and its derivatives (22 products) and other metabolites (22 products). Among these, 32 metabolites were specific for AUMC 4066 strain and 34 for AUMC 5705 strain, whereas 22 metabolites were produced by both strains on different tested substrates. Production of some metabolites depended on the substrate used. High number of metabolites was recorded in the red pigment extract obtained by both strains grown on malt broth and malt agar. Also, 42 aroma compounds were recorded (4 alcohols, 2 benzaldehydes, 27 esters, 3 lactones, 1 phenol, 1 terpenoid, 3 thiol compounds and acetate-3-mercapto butyric acid). Thin layer chromatography and GC/MS analyses revealed no mycotoxin citrinin in any media used for the growth of the two M. ruber strains.Svrha je rada bila proučiti kemijski sastav sojeva plijesni Monascus ruber pomoću plinske kromatografije i masene spektrometrije. Ispitan je i intenzitet crvenog pigmenta te sekundarni produkti metabolizma dvaju sojeva plijesni M. ruber (AUMC 4066 i AUMC 5705) uzgojenih na deset različitih podloga. Produkti metabolizma mogu se razvrstati u 4 skupine: spojevi koji snižavaju razinu kolesterola, antikancerogeni spojevi, prehrambene boje i esencijalne masne kiseline neophodne za ljudsko zdravlje. Plinskom je kromatografijom i masenom spektrometrijom pronađeno 88 produkata metabolizma, a među njima maslačna kiselina i njezini derivati (25), ostale masne kiseline i njihovi derivati (19), piran i njegovi derivati (22), te ostali metaboliti (22). Od ukupnog broja produkata, njih 33 je specifično za soj AUMC 4066, a 34 za soj AUMC 5705, dok su oba soja proizvela 22 produkta na različitim podlogama. Proizvodnja je produkata ovisila o upotrijebljenoj podlozi. Velik je broj metabolita pronađen u ekstraktima crvenog pigmenta iz oba soja uzgojena na podlogama od slada. Pronađena su 42 aromatska spoja, i to 4 alkohola, 27 estera, 3 laktona, 1 fenol, 1 terpenoid, 3 tiola i 1 merkapto spoj. Tankoslojnom i plinskom kromatografijom te masenom spektrometrijom nije pronađen mikotoksin citrinin ni u jednoj podlozi na kojoj su rasla ova dva soja plijesni M. ruber
Predictors of Long Covid 19 Syndrome
Background: Symptoms of covid persist in most cases with development of a multisystem syndrome called long covid syndrome.Objective: The aim of the work was to evaluate symptoms that persist after the acute stage of the disease in a cohort of patients with confirmed or suspected COVID 19 and to define the predictors for long COVID syndrome.Patients and method: This retrospective study involved 164 patients with previously confirmed or highly suspected COVID 19 and still attending to the post covid outpatient clinic in El-Minia University Chest Hospital complaining from persistence of symptoms or for regular follow up. Their data was obtained from their previous medical reports. Results: Post Covid 19 symptoms were found in about 86 % of the studied patients with 42.7% reported neuropsychiatric symptoms and 26.8% reported respiratory symptoms. The most common reported symptoms in nonsevere cases were the anxiety disorders (18.9%), followed by chronic fatigue and neuropathy (15.2%), while chronic dyspnea in 9.8% mostly in severe cases, while vertigo and headache in 9.1%, musculoskeletal symptoms in 6.1% and skin lesions in 3.7%.Conclusion: It could be concluded that persistence of symptoms is very common after acute Covid 19 infection. Chronic dyspnea was reported more frequently in severe cases while anxiety reported mostly by patients with mild disease
Stimuli-responsive hydrogels: smart state of-the-art platforms for cardiac tissue engineering
Biomedicine and tissue regeneration have made significant advancements recently, positively affecting the whole healthcare spectrum. This opened the way for them to develop their applications for revitalizing damaged tissues. Thus, their functionality will be restored. Cardiac tissue engineering (CTE) using curative procedures that combine biomolecules, biomimetic scaffolds, and cells plays a critical part in this path. Stimuli-responsive hydrogels (SRHs) are excellent three-dimensional (3D) biomaterials for tissue engineering (TE) and various biomedical applications. They can mimic the intrinsic tissues’ physicochemical, mechanical, and biological characteristics in a variety of ways. They also provide for 3D setup, adequate aqueous conditions, and the mechanical consistency required for cell development. Furthermore, they function as competent delivery platforms for various biomolecules. Many natural and synthetic polymers were used to fabricate these intelligent platforms with innovative enhanced features and specialized capabilities that are appropriate for CTE applications. In the present review, different strategies employed for CTE were outlined. The light was shed on the limitations of the use of conventional hydrogels in CTE. Moreover, diverse types of SRHs, their characteristics, assembly and exploitation for CTE were discussed. To summarize, recent development in the construction of SRHs increases their potential to operate as intelligent, sophisticated systems in the reconstruction of degenerated cardiac tissues
pH-sensitive nanoparticles containing 5-fluorouracil and leucovorin as an improved anti-cancer option for colon cancer.
Parenteral administration of chemotherapeutic drugs, 5-fluorouracil (5-FU) and leucovorin (LV), is commonly used to treat large bowel carcinomas such as colon cancer (CC) and colorectal carcinoma (CRC). Our study aims to design a novel nanoparticulate drug-delivery vehicle for oral use capable of colon-specific release. A modified double-emulsion solvent evaporation method was used in the preparation of pH-responsive Eudargit S100 polymeric nanoparticles, loaded with 5-FU/LV combination (5-FU/LV-loaded Eudargit S100 NPs). Our optimized drug-loaded NP showed a pH-responsive drug release and exhibited significantly more cytotoxic actions in cancer-cell lines than free drugs. These findings open the way for conducting clinical trials for colon malignancies treated with nanoparticles
Laparoscopic Splenectomy Alone for Sickle Cell Disease : Account of 50 paediatric cases
Objectives: In Oman, the most frequent indication for a splenectomy in children is sickle cell disease (SCD), which is one of the most common haematological disorders in the Gulf region. This study aimed to describe paediatric laparoscopic splenectomies alone for SCD at a tertiary hospital in Oman. Methods: This study was conducted between February 2010 and October 2015 at the Sultan Qaboos University Hospital, Muscat, Oman. The medical records of all children aged ≤15 years old undergoing splenectomies during the study period were reviewed. Results: A total of 71 children underwent laparoscopic splenectomies during the study period; of these, 50 children (28 male and 22 female) underwent laparoscopic splenectomies alone for SCD. The children’s weight ranged between 11–43 kg. The most common indication for a splenectomy was a recurrent splenic sequestration crisis (92%). Surgically removed spleens weighed between 155–1,200 g and measured between 9–22 cm. Operative times ranged between 66–204 minutes and intraoperative blood loss ranged between 10–800 mL. One patient required conversion to an open splenectomy. Postoperative complications were noted in only four patients. The median hospital stay duration was three days. Conclusion: Among this cohort, the mean operating time was comparable to that reported in the international literature. In addition, rates of conversion and postoperative complications were very low. These findings indicate that a laparoscopic splenectomy alone in paediatric patients with SCD is a feasible option
Environmental pressures and eco-innovation in manufacturing SMEs: the mediating effect of environmental capabilities
Purpose: Although environmental pressures have been covered in great detail in prior literature as the drivers of eco-innovation, there remains inconsistency in the empirical results concerning the effects of these pressures on eco-innovation behaviour. Hence, this paper aims to investigate the impact of environmental pressures, namely, regulatory pressure, green demand and competitive pressure, on eco-innovation among manufacturing SMEs. Moreover, it examined the mediating role of environmental capabilities on the environmental pressure–eco-innovation relationship. Design/methodology/approach: Quantitative data were collected using an online self-reported questionnaire survey to test the hypothesised model. A total of 183 valid questionnaires were collected from managers and owners of manufacturing SMEs in Egypt. Findings: The results of the data analysis using the Smart-PLS software package revealed that among environmental pressures, only green demand had a direct effect on eco-innovation. In addition, environmental capabilities only mediated the effect of competitive pressure on eco-innovation. Originality/value: This study has been one of the few addressing the issue of how the drivers of eco-innovation interact. It has also provided the managers and owners of SMEs and policymakers with practical implications
Institutional pressure and eco-innovation: The mediating role of green absorptive capacity and strategically environmental orientation among manufacturing SMEs in Egypt
With the growing concern about climate change, businesses have been under increasing pressure from regulatory agencies and customers to implement proactive environmental practices such as eco-innovation. While environmental pressures have been extensively discussed in the literature as drivers of eco-innovation, empirical evidence on the influence of these pressures on eco-innovation behaviour remains inconsistent. Therefore, the current study essentially aims to investigate the direct effect of institutional pressures, namely, regulation, eco-friendly product demand, and competitive pressure on eco-innovation, coupled with the indirect effect of these pressures by mediating internal drivers of eco-innovation including green absorptive capacity and strategically environmental orientation among manufacturing SMEs in Egypt. Based on a sample of 176 managers and owners of these enterprises, a cross-sectional survey is conducted to collect data related to research constructs. The results of data analysis using Smart-PLS show that all external pressures are not directly associated with eco-innovation. Of the six indirect hypothesized effects, only four indirect effects are supported. The results illustrate that green absorptive capacity mediates the relationship between institutional pressure (eco-friendly product demand and competitive pressure) and eco-innovation. The results also show that strategically environmental orientation mediates the relationship between institutional pressure (regulation and competitive pressure) and eco-innovation. This study provides an in-depth understanding of firms’ responses to institutional pressures as well as the notable implications for SMEs managers, policymakers and future researchers
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