111 research outputs found

    Effects of space plasma on an oxide coating of spacecraft's surface materials

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    The aim of this paper is to study the properties of the materials for spacecraft surfaces under the effects of simulated low Earth orbit (LEO) plasma environment to understand the effects of charging and discharging phenomena, which are known to take place when spacecraft is moving through space plasma in LEO. Anodized aluminum Al2O3 samples were prepared using electrochemical techniques with different thicknesses to investigate the role of the Al2O3 coating in the charging and discharging phenomena. Penning plasma source is used to generate plasma using Ar gas flowing through the vacuum chamber. The peak current and the voltage waveform associated with charging and discharging processes, when a negatively biased voltage is applied to the substrate, are discussed. The structural properties before and after plasma exposure are investigated through the morphology and optical analyses of the samples. Morphological analyses confirmed the significant contribution of space plasma in the variation of the crystalline structure, and sample characteristics are dependent on the value of the thickness. In addition, the results confirm the variation of optical properties and the microcrystalline structure over the surface of the anodic oxide film

    Knowledge, attitude and practice of long acting reversible hormonal contraception (LARHC) among women in urban upper Egypt

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    Background: The current study aims to assess the knowledge, attitude and practice of long acting reversible hormonal contraception (LARHC) among women in urban upper Egypt.Methods: A cross sectional study which included 902 married women, in the reproductive age, attending the outpatient clinics (Gynecology and family planning) of: 1-Assiut University Maternity Hospital, 2- Sohag University Hospital, and 3-Gehina General Hospital (MOH hospital) with current or previous use of any method of LARHC methods. A Questionnaire file was designed to assay knowledge attitude and practice of clients towards contraceptive methods. All data collected from clients reviewed separately to assess knowledge, attitude and practice of women towards contraceptive methods.Results: The most popular contraceptive method is COCs followed by IUD then DMPA. 99% of studied sample heard with good description about different types of LARHC. 54.9% of studied sample most popular/famous LARHC DMPA, most sources of information on LARHC were, Hospital, Relative/friends and health workers. 94.24% of the studied sample were in favor to use of LARHC, 94.2% of them agree to take a space between births, about 55.4% of them were health child and 61% comfortable lifestyle benefit from birth spacing, 33% of studied sample were maternal health, 68% of them were think/prefer to use implants, 64.5% of them didn’t pregnant while breastfeeding. 11% of sample women never used any contraception before and most reasons for not using contraception are fear of side effects, desire for more children, irregular sexual relationship, and husband opposition. Only 16.6 % of studied sample used LARHC before and most of them used DMPA, however 3 women who used DMPA get pregnant while using it.Conclusions: There is a good level of knowledge between upper Egypt women about LARHC methods

    Spermatozoal Fractalkine Signaling Pathway Is Upregulated in Subclinical Varicocele Patients with Normal Seminogram and Low-Level Leucospermia

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    Background. Fractalkine is produced in seminal plasma in small amounts and correlates with sperm motility. Purpose. To investigate the possible effect of low-level leucospermia on spermatozoa oxidative stress and sDNA fragmentation in patients with subclinical varicocele and apparently normal seminogram, and also to study the role of spermatozoal fractalkine and its receptor (CX3CR1) gene expression as a marker of spermatozoa inflammatory response. Methods. This study included 80 patients with subclinical varicocele (45 fertile and 35 infertile) and 45 age-matched fertile volunteers. In semen samples, fractalkine and CX3CR1 gene expression were investigated by qRT-PCR. Moreover, seminal plasma malondialdehyde (MDA) and total antioxidant capacity (TAC) were measured. Results. There are significant decrease in semen quality and significant increase in seminal leucocytes count in subclinical varicocele. Our results show a significant increase in MDA and TAC levels, DNA fragmentation, and expression levels of fractalkine and its receptor (CX3CR1) in subclinical varicocele groups. Conclusion. Subclinical varicocele induces seminal and spermatozoal subclinical inflammatory response in the form of low-level leucospermia and increased mRNA expression of the fractalkine signaling pathway, leading to increased spermatozoal ROS production, oxidative stress, and DNA fragmentation. These could cooperate in the pathogenesis of delayed fertility in males with subclinical varicocele

    Awareness, Perceptions and Beliefs About Physiotherapy Profession Among Orthopedists and Neurosurgeons Working in the Main Hospitals of the Ministry of Health in Gaza Strip

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    Background: - Healthcare professions have rapidly developed due to advancements in technology along with innovations over years, and Physiotherapists are considered as a key-member of collaborative inter-professional teams due to their broad scope of practice. - Increasing disabilities in Palestine due to occupation and other reasons, life expectancy and the special circumstances made it one of the most imperative socioeconomic medical issues in Gaza Strip. This emphasizes the need for the development and recognition of physiotherapy in multidisciplinary healthcare structures. - In order to deliver effective care, communication, cooperation and agreement between physicians and physiotherapist is essential. - If a physician were well informed about physiotherapy abilities in helping the treatments, prevent complications and decrease hospital stays, that would decrease the burden on the healthcare system. - Lack of knowledge about physiotherapy among medical professionals affects several aspects, including patients, the role of physiotherapy as a part of the healthcare teams, and the outcomes. Objectives: - The aim of the study was to identify awareness, perception and believes about physiotherapy among orthopedists and neurosurgeons. Methods: - A cross-sectional study was conducted between January – June 2019 at the three main hospitals of the Ministry of Health in Gaza Strip. The study population included Orthopedists and Neurosurgeons who work according to the settings. - The total collected samples were 67, and participants of the study were recruited through a Non-Probability convenience sample. - Data was collected through a questionnaire, that was designed in English, with four main parts, a total of 30 items, then data analysis using the (SPSS-V.22) and several statistical operations were done including Cross tabulation using chi-squarer with significance value was defined as p≤0.05. Results: - Results of this study showed that the awareness of orthopedists and neurosurgeons about physiotherapy was 95.5%. The study showed that 54.7% of these physicians received their knowledge through their studying. The study showed that 78.1% of physicians believe that the intervention of physiotherapy is in therapeutic exercises, while 57.8% believe that the biggest intervention is the use of electrical modalities, and 60.9% believe that it is manual therapy. The study found that 96.9% of physicians believe that physiotherapy plays an important role in the treatment plan for the patient. And 71.9% of the physicians believe that the physiotherapist has the right to return the patient to the physician due to misdiagnosis. The study indicated that 90.6% of physicians believe it is important to discuss the patient's discharge with a physiotherapist, and shocking result was that 95.3% of physicians say that they write on the referral what should a physiotherapist do to a patient, and that is a huge violation of the physiotherapists right of making their own decision. Conclusions: - There is a close association between orthopedists and neurosurgeons about physiotherapy. The study has shown that they have a clear awareness, perception and beliefs about physiotherapy. - This relationship should be supported and developed to provide the best possible treatment to patients

    Review: Biological determinants of between-animal variation in feed efficiency of growing beef cattle

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    Animal's feed efficiency in growing cattle (i.e. the animal ability to reach a market or adult BW with the least amount of feed intake), is a key factor in the beef cattle industry. Feeding systems have made huge progress to understand dietary factors influencing the average animal feed efficiency. However, there exists a considerable amount of animal-to-animal variation around the average feed efficiency observed in beef cattle reared in similar conditions, which is still far from being understood. This review aims to identify biological determinants and molecular pathways involved in the between-animal variation in feed efficiency with particular reference to growing beef cattle phenotyped for residual feed intake (RFI). Moreover, the review attempts to distinguish true potential determinants from those revealed through simple associations or indirectly linked to RFI through their association with feed intake. Most representative and studied biological processes which seem to be connected to feed efficiency were reviewed, such as feeding behaviour, digestion and methane production, rumen microbiome structure and functioning, energy metabolism at the whole body and cellular levels, protein turnover, hormone regulation and body composition. In addition, an overall molecular network analysis was conducted for unravelling networks and their linked functions involved in between-animal variation in feed efficiency. The results from this review suggest that feeding and digestive-related mechanisms could be associated with RFI mainly because they co-vary with feed intake. Although much more research is warranted, especially with high-forage diets, the role of feeding and digestive related mechanisms as true determinants of animal variability in feed efficiency could be minor. Concerning the metabolic-related mechanisms, despite the scarcity of studies using reference methods it seems that feed efficient animals have a significantly lower energy metabolic rate independent of the associated intake reduction. This lower heat production in feed efficient animals may result from a decreased protein turnover and a higher efficiency of ATP production in mitochondria, both mechanisms also identified in the molecular network analysis. In contrast, hormones and body composition could not be conclusively related to animal-to-animal variation in feed efficiency. The analysis of potential biological networks underlying RFI variations highlighted other significant pathways such as lipid metabolism and immunity and stress response. Finally, emerging knowledge suggests that metabolic functions underlying genetic variation in feed efficiency could be associated with other important traits in animal production. This emphasizes the relevance of understanding the biological basis of relevant animal traits to better define future balanced breeding programmes

    Neutralizing antibodies against SARS-CoV-2 are higher but decline faster in mRNA vaccinees compared to individuals with natural infection.

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    Waning protection against emerging SARS-CoV-2 variants by pre-existing antibodies elicited due to current vaccination or natural infection is a global concern. Whether this is due to the waning of immunity to SARS-COV-2 remains unclear. We aimed to investigate the dynamics of antibody isotype responses among vaccinated naïve (VN) and naturally infected (NI) individuals. We followed up antibody levels in COVID-19 mRNA-vaccinated subjects without prior infection (VN, n = 100) in two phases: phase-I (P-I) at ~ 1.4 and phase-II (P-II) at ~ 5.3 months. Antibody levels were compared to those of unvaccinated and naturally infected subjects (NI, n = 40) at ~ 1.7 (P-1) and 5.2 (P-II) months post-infection. Neutralizing antibodies (NTAb), anti-S-RBD-IgG, -IgM, and anti-S-IgA isotypes were measured. The VN group elicited significantly greater antibody responses (p < 0.001) than the NI group at P-I, except for IgM. In the VN group, a significant waning in antibody response was observed in all isotypes. There was about ~ a 4-fold decline in NTAb levels (p < 0.001), anti-S-RBD-IgG (~5-folds, p < 0.001), anti-S-RBD-IgM (~6-folds, p < 0.001), and anti-S1-IgA (2-folds, p < 0.001). In the NI group, a significant but less steady decline was notable in S-RBD-IgM (~2-folds, p < 0.001), and a much smaller but significant difference in NTAb (<2-folds, p < 0.001) anti-S-RBD IgG (<2-folds, p = 0.005). Unlike the VN group, the NI group mounted a lasting anti-S1-IgA response with no significant decline. Anti-S1-IgA, which were ~ 3 folds higher in VN subjects compared to NI in P-1 (p < 0.001), dropped to almost the same levels, with no significant difference observed between the two groups in P-II. While double-dose mRNA vaccination boosted antibody levels, vaccinated individuals' 'boost' was relatively short-lived.This work was made possible by WHO grant numbers COVID-19-22-43 and UREP28–173–3-057 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors

    Relating circulating thyroid hormone concentrations to serum interleukins-6 and -10 in association with non-thyroidal illnesses including chronic renal insufficiency

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    <p>Abstract</p> <p>Background</p> <p>Because of the possible role of cytokines including interleukins (IL) in systemic non-thyroidal illnesses' (NTI) pathogenesis and consequently the frequently associated alterations in thyroid hormone (TH) concentrations constituting the euthyroid sick syndrome (ESS), we aimed in this research to elucidate the possible relation between IL-6 & IL-10 and any documented ESS in a cohort of patients with NTI.</p> <p>Methods</p> <p>Sixty patients and twenty healthy volunteers were recruited. The patients were subdivided into three subgroups depending on their underlying NTI and included 20 patients with chronic renal insufficiency (CRI), congestive heart failure (CHF), and ICU patients with myocardial infarction (MI). Determination of the circulating serum levels of IL-6 and IL-10, thyroid stimulating hormone (TSH), as well as total T4 and T3 was carried out.</p> <p>Results</p> <p>In the whole group of patients, we detected a significantly lower T3 and T4 levels compared to control subjects (0.938 ± 0.477 vs 1.345 ± 0.44 nmol/L, p = 0.001 and 47.9 ± 28.41 vs 108 ± 19.49 nmol/L, p < 0.0001 respectively) while the TSH level was normal (1.08+0.518 μIU/L). Further, IL-6 was substantially higher above controls' levels (105.18 ± 72.01 vs 3.35 ± 1.18 ng/L, p < 0.00001) and correlated negatively with both T3 and T4 (r = -0.620, p < 0.0001 & -0.267, p < 0.001, respectively). Similarly was IL-10 level (74.13 ± 52.99 vs 2.64 ± 0.92 ng/ml, p < 0.00001) that correlated negatively with T3 (r = -0.512, p < 0.0001) but not T4. Interestingly, both interleukins correlated positively (r = 0.770, p = <0.001). Moreover, IL-6 (R<sup>2 </sup>= 0.338, p = 0.001) and not IL-10 was a predictor of low T3 levels with only a borderline significance for T4 (R<sup>2 </sup>= 0.082, p = 0.071).</p> <p>By subgroup analysis, the proportion of patients with subnormal T3, T4, and TSH levels was highest in the MI patients (70%, 70%, and 72%, respectively) who displayed the greatest IL-6 and IL-10 concentrations (192.5 ± 45.1 ng/L & 122.95 ± 46.1 ng/L, respectively) compared with CHF (82.95 ± 28.9 ng/L & 69.05 ± 44.0 ng/L, respectively) and CRI patients (40.05 ± 28.9 ng/L & 30.4 ± 10.6 ng/L, respectively). Surprisingly, CRI patients showed the least disturbance in IL-6 and IL-10 despite the lower levels of T3, T4, and TSH in a higher proportion of them compared to CHF patients (40%, 45%, & 26% vs 35%, 25%, & 18%, respectively).</p> <p>Conclusion</p> <p>the high prevalence of ESS we detected in NTI including CRI may be linked to IL-6 and IL-10 alterations. Further, perturbation of IL-6 and not IL-10 might be involved in ESS pathogenesis although it is not the only key player as suggested by our findings in CRI.</p

    Chemical proteomics approaches for identifying the cellular targets of natural products.

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    Covering: 2010 up to 2016. Deconvoluting the mode of action of natural products and drugs remains one of the biggest challenges in chemistry and biology today. Chemical proteomics is a growing area of chemical biology that seeks to design small molecule probes to understand protein function. In the context of natural products, chemical proteomics can be used to identify the protein binding partners or targets of small molecules in live cells. Here, we highlight recent examples of chemical probes based on natural products and their application for target identification. The review focuses on probes that can be covalently linked to their target proteins (either via intrinsic chemical reactivity or via the introduction of photocrosslinkers), and can be applied "in situ" - in living systems rather than cell lysates. We also focus here on strategies that employ a click reaction, the copper-catalysed azide-alkyne cycloaddition reaction (CuAAC), to allow minimal functionalisation of natural product scaffolds with an alkyne or azide tag. We also discuss 'competitive mode' approaches that screen for natural products that compete with a well-characterised chemical probe for binding to a particular set of protein targets. Fuelled by advances in mass spectrometry instrumentation and bioinformatics, many modern strategies are now embracing quantitative proteomics to help define the true interacting partners of probes, and we highlight the opportunities this rapidly evolving technology provides in chemical proteomics. Finally, some of the limitations and challenges of chemical proteomics approaches are discussed
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