39 research outputs found
Beyond the pandemic : COVID-19 pandemic changed the face of life
Funding Information: This work was supported by the Swedish Research Council Vetenskapsr?det (VR grant 2016?05885). Funding Information: Acknowledgments: H.R. El-Seedi is very grateful to the Swedish Research links grant VR 2016– 05885 and the Department of Molecular Biosciences, Wenner-Grens Institute, Stockholm University, Sweden, for the financial support. Publisher Copyright: © 2021 by the au-thors. Licensee MDPI, Basel, Switzerland.The COVID-19 pandemic is a serious challenge for societies around the globe as entire populations have fallen victim to the infectious spread and have taken up social distancing. In many countries, people have had to self-isolate and to be confined to their homes for several weeks to months to prevent the spread of the virus. Social distancing measures have had both negative and positive impacts on various aspects of economies, lifestyles, education, transportation, food supply, health, social life, and mental wellbeing. On other hands, due to reduced population movements and the decline in human activities, gas emissions decreased and the ozone layer improved; this had a positive impact on Earth’s weather and environment. Overall, the COVID-19 pandemic has negative effects on human activities and positive impacts on nature. This study discusses the impact of the COVID-19 pandemic on different life aspects including the economy, social life, health, education, and the environment.publishersversionPeer reviewe
On the transition from static to dynamic boundary friction of lubricated PEEK for a spreading adhesive contact by macroscopic oscillatory tribometry
The tribology of lubricated poly(ether ether ketone) (PEEK)steel tribosystems was investigated in the static and boundary friction regime. Pentaerythrite ester and trimellitic acid ester were used as lubricants. The lubricants differed in their molecular structure but showed only minor differences in their rheological and cohesive energetic properties. In order to investigate the effect of the lubricants on static and dynamic friction, macroscopic oscillatory tribometry experiments and gliding experiments were carried out. The surface and interfacial energies of PEEK, lubricant, and steel, which can be used to determine e.g. the spreading tendency of the lubricant, were employed to explain the tribological characteristics of the system. The gliding experiments exhibited a velocity dependence of the coefficient of friction which indicates a rate-and-state type of friction. Trimellitic acid ester resulted in the lowest static and dynamic friction values due to its high tendency to spread. A different static friction behavior was found for pentaerythrite ester, which indicates a possible lubricant-induced mobilization of the polymer surface chains. This finding was supported by an increased interaction energy measured by contact angle measurements. The macroscopic oscillatory tribometry was shown to be a unique and precise method to investigate the transition from static to dynamic friction and to quantify macroscopic adhesive friction. Both types of experiments used a polished steel surface as a frictional partner, which favors the adhesive component of friction. However, the results for the lubricated contacts of polished steel surfaces in the boundary lubrication regime can give some insight into effects of the polymer transfer to rough steel surfaces in the mixed lubrication regime
The transition from static to dynamic boundary friction of a lubricated spreading and a non-spreading adhesive contact by macroscopic oscillatory tribometry
Lubricated poly(ether ether ketone) (PEEK) and polyamide (PA46)steel tribosystems were investigated. They show a complex but systematic transition behavior from static to boundary friction, to dynamic friction or to mixed-lubrication. Nonstandard macroscopic oscillatory tribometry as well as gliding experiments were carried out. A previous study showed that the surface and interfacial energies of PEEK, lubricant and steel can indicate trends in the tribological behavior. In the current study, these findings are confirmed for PA46 and a wider range of lubricants. It was shown that a reversal of the order of the work of spreading of two lubricants by switching from PEEK to PA46 as polymer component in the tribological system also resulted in a reversal of the coefficient of friction (COF) a t low gliding velocities for these systems. The adhesion threshold of PA46 with the non-spreading lubricants water, glycerine, a waterglycerine mixture, ethylene glycol and poly-1-decene decreased with increasing solving tendency of the lubricants in contrast to the previous results for spreading lubricants for PEEK. Furthermore, the onset of forced wetting was studied for lubricants with different surface and interfacial energies and viscosities η. In general, a 1/η dependency was observed for the velocity which marks the onset of forced wetting. This agrees with theoretical models
The utility of 64-multidetector computed tomography in the diagnosis and staging of hepatoblastoma patients
Objective: To assess the utility of 64 MDCT in the diagnosis, staging and follow-up of HB patients.
Patients & methods: This study included 17 children, 9 males and 8 females with HB from multiple centers aged 6 months- 3 years. Patients were subjected to complete clinical examination and laboratory investigations at presentation and during follow-up. Patients were evaluated, staged and treated according to SIOPEL HB protocols for management. Imaging evaluation was conducted using abdominal U/S, bone scan and MDCT for chest and abdomen.
Results: All patients were presented with abdominal mass and elevated AFP level, Jaundice seen in only 1 patient. On MDCT, 13 patients had single focal lesion, 2 patients had multiple foci and 2 patients showed diffuse disease. MDCT was more accurate than US in detecting site, multiplicity, density and lymph nodes (LNs). Regarding tumor staging, MDCT findings were confirmed surgically. In follow-up of patients MDCT was detected with accuracy residual or recurrent lesions in 3 cases.
Conclusion: MDCT in children with HB accurately displayed the extent of hepatic involvement by tumor, tumor staging and its proximity to vascular structures that help the surgeon to identify the tumor resectability and can be used in follow-up
Down-regulation of MSH3 and MSH6 genes in female breast cancer patients receiving taxane-based therapy
Abstract Background The DNA in each cell in our body is constantly in danger of becoming damaged. Most DNA damage gets repaired straight away via many different proteins encoded by DNA—repair genes. MSH3 and MSH6 are pivotal DNA repair genes maintaining human genome integrity. Dysregulated expression of such genes has its implications resulting in developing of adverse reactions in cancer breast patients receiving taxanes. Cancer chemotherapy with some of taxane class of agents are associated with significant neurotoxicity, arthralgias and myalgias that may offset the therapeutic benefits of taxane use. Our aim is to identify gene expression pattern of MSH3 and MSH6 DNA mismatch repair genes in female breast cancer patients who develop adverse reactions to taxane-based therapy. One hundred and five patients with histologically proven breast cancer who received paclitaxel (PTX) as a single agent or combination therapy have been enrolled along with a group of 50 females with benign breast lesions serving as controls.Gene expression studies of mismatch repair genes (MMR) genes; MSH3 and MSH6; have been performed by real-time PCR. Patients were divided into groups according to the determined type/grade of PTX-based toxicity and fold changes of both genes were estimated. Results In the present work both MMR genes showed significantly lower expression in all the studied patients compared to benign cases as a control group. Toxicity findings were encountered in 75.2% of the studied patient cohort. The most common observed type of toxicity was peripheral neuropathy (PN), 58.1% of the studied patients. Both MSH3 and MSH6 genes were significantly down-regulated in the presence of high grade PN toxicity ≥ 2 (p = 0.034 and 0.01); diarrhea toxicity (p = 0.02 and 0.008); dyspnea (p = 0.01 and 0.016) respectively and bone pain (p = 0.024 for MSH6 only). Conclusion Dysregulated expression of MMR GENES [MSH3and MSH6] can be implicated in paclitaxel—induced toxicity experienced by some cancer breast patients
SOLUTION OF SOME TWO-DIMENSIONAL INCOMPRESSIBLE FLUID FLOW AND HEAT TRANSFER PROBLEMS, USING A CONTROL VOLUME FINITE-ELEMENT METHOD
UPLC-MS/MS Analysis of Naturally Derived <i>Apis mellifera</i> Products and Their Promising Effects against Cadmium-Induced Adverse Effects in Female Rats
Honeybee products arouse interest in society due to their natural origin and range of important biological properties. Propolis (P) and royal jelly (RJ) attract scientists’ attention because they exhibit antioxidant, anti-inflammatory, anti-bacterial, anti-tumor, and immunomodulatory abilities. In this study, we tested whether P and RJ could mitigate the adverse effects of cadmium (Cd) exposure, with particular emphasis on the reproductive function in female rats. In this line, one week of pretreatment was established. Six experimental groups were created, including (i) the control group (without any supplementation), (ii) the Cd group (receiving CdCl2 in a dose of 4.5 mg/kg/day), (iii) the P group (50 mg of P/kg/day), (iv) RJ group (200 mg of RJ/kg/day), (v) P + Cd group (rats pretreated with P and then treated with P and Cd simultaneously), (vi) RJ + Cd group (animals pretreated with RJ before receiving CdCl2 simultaneously with RJ). Cd treatment of rats adversely affected a number of measured parameters, including body weight, ovarian structure and ultrastructure, oxidative stress parameters, increased ovarian Cd content and prolonged the estrous cycle. Pretreatment and then cotreatment with P or RJ and Cd alleviated the adverse effects of Cd, transferring the clusters in the PCA analysis chart toward the control group. However, clusters for cotreated groups were still distinctly separated from the control and P, or RJ alone treated groups. Most likely, investigated honeybee products can alter Cd absorption in the gut and/or increase its excretion through the kidneys and/or mitigate oxidative stress by various components. Undoubtedly, pretreatment with P or RJ can effectively prepare the organism to overcome harmful insults. Although the chemical composition of RJ and P is relatively well known, focusing on proportion, duration, and scheme of treatment, as well as the effects of particular components, may provide interesting data in the future. In the era of returning to natural products, both P and RJ seem valuable materials for further consideration as anti-infertility agents