47 research outputs found
Temperature affects the silicate morphology in a diatom
No full textTemperature affects the silicate morphology in a diatom Javaheri, N.; Dries, R.M.; Burson, A.M.; Stal, L.J.; Sloot, P.M.A.; Kaandorp, J.A. Published in: Scientific Reports DOI: 10.1038/srep11652 Link to publication Citation for published version (APA): Javaheri, N., Dries, R., Burson, A., Stal, L. J., Sloot, P. M. A., & Kaandorp, J. A. (2015). Temperature affects the silicate morphology in a diatom. Scientific Reports, 5, [11652]. https://doi.org/10.1038/srep11652 General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. , and 23 °C ). We observed three distinct temperature-dependent growth phases. The morphology of silica was investigated using scanning electron microscopy followed by image analysis and supervised learning. The silica in the valves of the same species showed different structures: a mesh-like pattern in silicon-rich cultures and a treelike pattern in silicon-limited cultures. Moreover, temperature affected this silica pattern, especially in silicon-limited cultures. We conclude that cells grown at 14 °C and 18 °C divide more successfully in Si-limited conditions by developing a tree-like pattern (lower silicification)
Phänotypisierung von Mäusen mit genetischen Defekten relevant zum allergischen Erkrankungen: Proteinase 3/neutrophil Elastase Doppel-Knockout-Mäusen
No full textUnderstanding the type of cellular inflammation in acute severe asthma has important implications not only for the treatment of disease but also for its prevention. Although there is clear evidence demonstrating distinct infiltration and presence of neutrophils in asthma, their specific function for the disease is not fully elucidated.
The granule-associated elastase homologues neutrophil elastase and proteinase 3 are involved in immune defense reactions of neutrophils.
The use of genetically engineered animal models to explore the function of genes and for the selection of appropriate drug targets holds great promise in accelerating the development of valuable therapies. Model organisms, especially the mouse, have proven to be important tools to learn more about gene functions.
Understanding the role of neutrophils and its proteases has important implication not only for the treatment of asthma but also for its prevention.
In this study the role of neutrophil proteases in an animal model of asthma was investigated. We mainly focused on type I allergic reactions. Intrestingly, we found that after aerosol challenge of mice lacking the neutrophil proteases, Elastase and proteinase 3, normal attending of neutrophils in bronchial lumen can be followed by recruitment /infiltration of the normal levels of eosinophils.
Thus, surprisingly, our primary hypothesis that impaired neutrophils may cause significant changes in eosinophils infiltration in bronchoalveolar lavage was not confirmed. This observation raises the hypothesis that neutrophil serine proteases may exert more subtle effects such a delayed cellular clearance in the inflammation site.Es gibt klare Beweise für eine starke Infiltration von Neutrophilen bei Asthma. Die Aufklärung der Rolle von Neutrophilen und deren Proteasen, die Neutrophilen Elastase und Proteinase 3 kann somit wichtige Erkenntnisse für Prävention und Therapie von Asthma liefern. In dieser Studie wurde die Rolle der Neutrophilenproteasen in einem Asthma-Mausmodell untersucht. Zusammenfassend lässt sich feststellen, dass ein Defekt von Neutrophilenproteasen die Infiltration von Eosinophilen nicht beeinträchtigt. Es ist jedoch möglich, dass Neutrophilenproteasen an der Beseitigung des zellulären Infiltrates am Entzündungsort beteiligt sein können
Prevalence and etiologies of macrosomia and low birth weight in 1000 neonates at Javaheri hospital in Tehran
No full textBackground and aimLow birth weight is one of the important problems in many societies especially developing ones. The survival rate of infants has a direct relationship with their birth weight. The aim of This cross-sectional study was to determine the prevalence and etiologies of Prevalence and etiologies of macrosomia and low birth weight in 1000 neonates of low birth weight (LBW) as well as macrosomia and their possible etiologies. Materials and methods1000 neonates were sequentially selected by nonrandom sampling method over 6 months in 2006 at Javaheri hospital in Tehran. By reviewing their medical records, the birth weight of the subjects and other variables of the study were assessed. Independent T and Qui-square tests were used for data analysis. FindingsIn this study cross sectional- study mean weigh of the neonates was 2957±910 gr. 7% of the subjects suffered from low birth weight (mean=2371±260) and 3% had macrosomia (mean=4247±240). A significant relationship was found between birth weight and gestational age of the neonates. 10% of mothers having neonates with macrosomia had gestational diabetes. The etiology of macrosomia was not known in most cases. The most common causes of low birth weight included premature rupture of membranes, twin gestation, fetal distress and maternal conditions. ConclusionAppropriate gestational care, risk factor detection before pregnancy and improvement of quantity as well as quality of maternal child health services can reduce the number of low- birth-weight infants. Keywords: Macrosomia, Low birth weight, Prevalence, Etiology. *Corresponding Author: Dr. Masoomeh, Hematyar. Islamic Azad University, College of Medicine, Tehran, Iran. E-mail: [email protected]
Generating CRISPR-dCas9 System in Clostridium difficile Bacteria
No full textThe increasing incidence of Clostridium difficile-associated disease, and its resistance to a number of antibiotics, highlight the need for additional countermeasures. The main issue that hampers the design of antibiotics is a lack of appropriate tools to study the molecular biology of C.difficile in great detail. Insight into the function of DNA replication genes and the protein they encode might eventually lead to the development of specific inhibitors that can be exploited as drugs. By means of CRISPR-dCas9 system, we designed and engineered a construct that is capable of targeting specific replication genes and silence those genes. Our design is composed of a nuclease-deactivated Cas9 (dCas9) protein and a customized single-guided RNA (sgRNA) with a 20-basepair complementary region to target replication genes in C.difficile. Co-expression of dCas9 and sgRNA can efficiently block transcription by interfering with DNA replication process. We developed a set of conjugative plasmids that carries appropriate Pveg-sgRNA targets to repress CD0001 (dnaA) and CD1214 (spo0A) genes in C.difficile. We also built a construct with dCas9 and its inducible promoter (Pcpr) that can be conjugated into C.difficile. Once both constructs are transformed into C.difficile 630 erm, we will be able to analyze and detect potential phenotypes expressed in the presence of dCas9.Biomedical ElectronicsBiomedical EngineeringMechanical, Maritime and Materials Engineerin
Fueling the heart: What are the optimal dietary strategies in heart failure?
Get PDFOBJECTIVES: Heart failure (HF) is a global health concern with rising incidence and poor prognosis. While the essential role of nutritional and dietary strategies in HF patients is acknowledged in the existing scientific guidelines and clinical practice, there are no comprehensive nutritional recommendations for optimal dietary management of HF.
METHODS: In this review, we discuss results from recent studies on the obesity paradox and the effects of calorie restriction and weight loss, intermittent fasting, the Western diet, the Mediterranean diet, the ketogenic diet, and the DASH diet on HF progression.
RESULTS: Many of these strategies remain under clinical and basic investigation for their safety and efficacy, and there is considerable heterogeneity in the observed response, presumably because of heterogeneity in the pathogenesis of different types of HF. In addition, while specific aspects of cardiac metabolism, such as changes in ketone body utilization, might underlie the effects of certain dietary strategies on the heart, there is a critical divide between supplement strategies (i.e., with ketones) and dietary strategies that impact ketogenesis.
CONCLUSION: This review aims to highlight this gap by exploring emerging evidence supporting the importance of personalized dietary strategies in preventing progression and improving outcomes in the context of HF
Effect of dietary carbohydrate restriction on cardiometabolic function in type 2 diabetes: weight loss and beyond
No full textH. pylori virulence factors: influence on immune system and pathology.
No full textHelicobacter pylori is the most widespread chronic bacterial agent in humans and is well recognized for its association with ulcer disease and gastric cancer, with both representing major global health and socioeconomic issues. Given the high level of adaptation and the coevolution of this bacterium with its human host, a thorough and multidirectional view of the specific microbiological characteristics of this infection as well as the host physiology is needed in order to develop novel means of prevention of therapy. This review aims to pinpoint some of these potentially important angles, which have to be considered mutually when studying H. pylori's pathogenicity. The host's biological changes due to the virulence factors are a valuable pillar of H. pylori research as are the mechanisms by which bacteria provoke these changes. In this context, necessary adhesion molecules and significant virulence factors of H. pylori are discussed. Moreover, metabolism of the bacteria, one of the most important aspects for a better understanding of bacterial physiology and consequently possible therapeutic and prophylactic strategies, is addressed. On the other hand, we discuss the recent experimental proofs of the "hygiene hypothesis" in correlation with Helicobacter's infection, which adds another aspect of complexity to this infection
Steel pipeline for the hydrogen storage and delivery: metallurgical viewpoint for Finnish ecosystem
Get PDFAbstract
For more than a century, hydrogen has been used as an industrial chemical to produce ammonia for fertilizers and to process intermediate products in oil refineries. However, hydrogen has recently received renewed interest due to its ability to reduce carbon emissions to the atmosphere, particularly in the steel-making industries. Thus, hydrogen has the potential to play a critical role in combating climate change and achieving Finland's national goal of carbon neutrality by 2035. In this regard, national and global demand for hydrogen is rapidly increasing, and it is now three times more than what it was in 1975. The production and supply of hydrogen for industrial consumption would be a massive business that is expected to expand even faster than before. According to the IEA, the total demand for hydrogen in pure and mixed gas was approximately 115-120 million tones in 2018. (Gaseous) hydrogen can be efficiently transported by pipeline networks at a pressure of typically <100 bar. Pipelines provide an economical means of transporting hydrogen in large quantities over long/short distances, and hence they are often found serving end users who take hydrogen from a local central source of production. Nevertheless, the correct pipe material for hydrogen distribution must be designed and used, and the current natural gas pipeline infrastructure must be upgraded significantly if it is to be used for the delivery of pure hydrogen at high pressure. Hence, new research is needed to focus mainly on the possibility of use/modification of available natural gas pipeline network for hydrogen delivery as well as the study on the new economical pipeline material, exclusively for hydrogen transportation and storage.Abstract
For more than a century, hydrogen has been used as an industrial chemical to produce ammonia for fertilizers and to process intermediate products in oil refineries. However, hydrogen has recently received renewed interest due to its ability to reduce carbon emissions to the atmosphere, particularly in the steel-making industries. Thus, hydrogen has the potential to play a critical role in combating climate change and achieving Finland's national goal of carbon neutrality by 2035. In this regard, national and global demand for hydrogen is rapidly increasing, and it is now three times more than what it was in 1975. The production and supply of hydrogen for industrial consumption would be a massive business that is expected to expand even faster than before. According to the IEA, the total demand for hydrogen in pure and mixed gas was approximately 115-120 million tones in 2018. (Gaseous) hydrogen can be efficiently transported by pipeline networks at a pressure of typically <100 bar. Pipelines provide an economical means of transporting hydrogen in large quantities over long/short distances, and hence they are often found serving end users who take hydrogen from a local central source of production. Nevertheless, the correct pipe material for hydrogen distribution must be designed and used, and the current natural gas pipeline infrastructure must be upgraded significantly if it is to be used for the delivery of pure hydrogen at high pressure. Hence, new research is needed to focus mainly on the possibility of use/modification of available natural gas pipeline network for hydrogen delivery as well as the study on the new economical pipeline material, exclusively for hydrogen transportation and storage
Correction to: Fatigue assessment of the welded joints containing process relevant imperfections (Welding in the World, (2019), 63, 2, (249-261), 10.1007/s40194-018-00676-y)
No full textS.1903In the original version of this article the author René Fenzl is missing due to an oversight. The correct author list is as given in this correction.63Nr.
