239 research outputs found

    Application of Lignins in Formulation and Manufacturing Bio- Based Polyurethanes by 31P NMR Spectroscopy

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    The application of several industrial and technical biomass lignins from forestry and agricultural residues extracted by different chemical pulping processes in view of bio-based polyurethanes were studied. Several qualitative and quantitative methods were utilized to characterize and elucidate lignin profiles by evaluating their physical and chemical properties as a potential substitute for petroleum-based polyols. The morphology, molecular weight distributions, elemental compositions, glass transition temperature and several important functional groups containing hydroxyl units were classified and their contents were determined quantitatively. In this chapter, lignin substitution in polyurethane by (i) direct substitution, (ii) with combination of polyols or (iii) chemically modified was reviewed. The emerging information aims at addressing a number of pressing issues relevant to the scientific development for value-added applications from lignins during industrial production of biofoams

    Phytochemistry, pharmacology, and therapeutic uses of black seed (Nigella sativa)

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    Black seed (Nigella sativa) is an annual flowering plant from Ranunculaceae family, native to southwest Asia. This plant has many food and medicinal uses. The use of its seeds and oil is common for treatment of many diseases, including rheumatoid arthritis, asthma, inflammatory diseases, diabetes and digestive diseases. The purpose of this study was to provide a comprehensive review on the scientific reports that have been published about N. sativa. The facts and statistics presented in this review article were gathered from the journals accessible in creditable databases such as Science Direct, Medline, PubMed, Scopus, EBSCO, EMBASE, SID and IranMedex. The keywords searched in Persian and English books on medicinal plants and traditional medicine, as well as the above reputable databases were “Black seed”, ”Nigella sativa“, “therapeutic effect”, and “medicinal plant”. The results showed that N. sativa has many biological effects such as anti-inflammatory, anti-hyperlipidemic, anti-microbial, anti-cancer, anti-oxidant, anti-diabetic, anti-hypertensive, and wound healing activities. It also has effects on reproductive, digestive, immune and central nervous systems, such as anticonvulsant and analgesic activities. In summary, it can be used as a valuable plant for production of new drugs for treatment of many diseases

    Mutational Analysis of the Arf1•GTP/Arf GAP Interface Reveals an Arf1 Mutant that Selectively Affects the Arf GAP ASAP1

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    SummaryArf1 is a GTP binding protein that functions at a number of cellular sites to control membrane traffic and actin remodeling. Arf1 is regulated by site-specific GTPase-activating proteins (GAPs). The combined results of crystallographic and biochemical studies [1–3] have led to the proposal that Arf1 GAPs differ in the specific interface formed with Arf1. To test this hypothesis, we have used mutagenesis to examine the interaction of three Arf GAPs (ASAP1, AGAP1, and ArfGAP1) with switch 1, switch 2, and α helix3 of Arf1. The GAPs were similar in being affected by mutations in switch 1 and 2. However, effects of a mutation within α helix3 and specific mutations within switch 1 and 2 differed among the GAPs. The largest differences were observed with a change of isoleucine 46 to aspartate ([I46D]Arf1), which reduced ASAP1-induced catalysis by ∼10,000-fold but had a 3-fold effect on AGAP1. The reduction was due to an isolated effect on the catalytic rate, kcat. In vivo [I46D]Arf1 had no detectable effect on the Golgi apparatus but, instead, functioned as a constitutively active mutant in the cell periphery, affecting the localization of ASAP1 and paxillin. Based on our results, we conclude that the contribution of specific residues within switch 1 of Arf to binding and achieving a transition state toward GTP hydrolysis differs among Arf GAPs

    The progenitors of the intra-cluster light and intra-cluster globular clusters in galaxy groups and clusters

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    We use the IllustrisTNG50 cosmological hydrodynamical simulation, complemented by a catalog of tagged globular clusters, to investigate the properties and build up of two extended luminous components: the intra-cluster light (ICL) and the intra-cluster globular clusters (ICGC). We select the 39 most massive groups and clusters in the box, spanning the range of virial masses 5×1012<M200/M<2×10145 \times 10^{12} < \rm M_{200}/\rm M_{\odot} < 2 \times 10^{14}. We find good agreement between predictions from the simulations and current observational estimates of the fraction of mass in the ICL and its radial extension. The stellar mass of the ICL is only 10%20%\sim10\%-20\% of the stellar mass in the central galaxy but encodes useful information on the assembly history of the group or cluster. About half the ICL in all our systems is brought in by galaxies in a narrow stellar mass range, M=10101011M_*=10^{10}-10^{11} M\rm M_{\odot}. However, the contribution of low-mass galaxies (M<1010M_*<10^{10} M\rm M_{\odot}) to the build-up of the ICL varies broadly from system to system, 5%45%\sim 5\%-45\%, a feature that might be recovered from the observable properties of the ICL at z=0z=0. At fixed virial mass, systems where the accretion of dwarf galaxies plays an important role have shallower metallicity profiles, less metal content and a lower stellar mass in the ICL than systems where the main contributors are more massive galaxies. We show that intra-cluster GCs are also good tracers of this history, representing a valuable alternative when diffuse light is not detectable

    (m-Phenyl­enedimethyl­ene)diammonium p-nitro­phenyl­phosphate perchlorate

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    The title compound, C8H14N2 2+·C12H8N2O8P−·ClO4 −, was formed by the reaction of α,α-bis-m-xylenediamine and sodium bis-p-nitro­phenyl­phosphate in the presence of Zn(ClO4)·6H2O in methanol solution. The two amine groups of the m-xylenediammonium ion are each protonated and each hydrogen-bonded to two O atoms of the phosphate anion, which acts as a 1,3-bridge. The ammonium groups are arranged matched face to face and each pair is doubly bridged by two perchlorate ions through hydrogen bonding. In addition, there are also weak C—H⋯O inter­actions. Both the N—H⋯O and C—H⋯O inter­actions are contained in a channel down the a axis. The perchlorate oxygen atoms are disordered over two positions with site occupancy factors of ca 0.7 and 0.3

    The effects of celery leave extract on male hormones in rats

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    Introduction: Celery (Apium graveolens) belongs to the Umbelliferae family, and has a plenty of nutritional and pharmaceutical applications. The presence of phytoestrogenic compounds has been reported in this plant. These compounds may affect the pituitary-gonad axis. The aim of the present study was to evaluate the efficacy of hydro-alcoholic extracts of celery leaves on serum levels of testosterone, LH and FSH in male rats. Methods: In this experimental study, 32 male Wistar rats were divided into four groups, eight rats included in each. The control group did not receive any treatment. The placebo group received distilled water and the case groups received 200 and 300 mg/kg/B.W of hydro-alcoholic celery leaf extract for 20 consecutive days by oral administration. After completion of the treatment, the rats were anesthetized and blood sampling from their heart was carried out. Then, serum levels of testosterone, LH and FSH were measured using immunoassay methods. The obtained data were analyzed by the SPSS using the statistical ANOVA test. Results: The level of LH in the case group receiving 200 mg/kg B.W of celery extract showed a significant decrease compared with the control and placebo groups (P&lt;0.05). The level of FSH and testosterone in case groups did not show any significant difference in comparison with the control group (P&gt;0.05). Conclusion: The result of the present study shows that in the administered dose, celery extract does not have any considerable side effect on the secretion of hormones in male rats.</p

    Therapeutic and pharmacological potential of <em>Foeniculum vulgare</em> Mill: a review

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    Introduction: Fennel (Foeniculum vulgare Mill) is one of the oldest spice plants which, due to its economic importance and significant pharmaceutical industry applications, is considered as one of the world&rsquo;s most important medicinal plants. The purpose of this study is to investigate and collect scientific reports such as morphological characteristics, phytochemical compounds and evaluation of the therapeutic properties of this valuable medicinal plant that have been published. Methods: In order to gather the information the keywords Fennel and Foeniculum vulgare mill, therapeutic, and pharmacology have been searched until January 1, 2015 from journals accessible in databases such as ScienceDirect, Scopus, EBSCO, Medline, PubMed, Embase, SID and Iran Medex. Results: The results showed that this plant has various pharmacological properties including antioxidant, anti-cancer activity, anti-inflammatory, antifungal, anti-bacterial and estrogenic effects which are probably due to the presence of aromatic compounds such as anethole, estragole and fenshon. Conclusion: Fennel possesses various pharmacological properties and the fennel bioactive molecules play an important role in human health, hence, it might be used for different drug productions.</p

    A giant thin stellar stream in the Coma Galaxy Cluster

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    The study of dynamically cold stellar streams reveals information about the gravitational potential where they reside and provides important constraints on the properties of dark matter. However, the intrinsic faintness of these streams makes their detection beyond Local environments highly challenging. Here, we report the detection of an extremely faint stellar stream (μg, max = 29.5 mag arcsec-2) with an extraordinarily coherent and thin morphology in the Coma Galaxy Cluster. This Giant Coma Stream spans ∼510 kpc in length and appears as a free-floating structure located at a projected distance of 0.8 Mpc from the center of Coma. We do not identify any potential galaxy remnant or core, and the stream structure appears featureless in our data. We interpret the Giant Coma Stream as being a recently accreted, tidally disrupting passive dwarf. Using the Illustris-TNG50 simulation, we identify a case with similar characteristics, showing that, although rare, these types of streams are predicted to exist in N-CDM. Our work unveils the presence of free-floating, extremely faint and thin stellar streams in galaxy clusters, widening the environmental context in which these objects are found ahead of their promising future application in the study of the properties of dark matter.</p

    A giant thin stellar stream in the Coma Galaxy Cluster

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    The study of dynamically cold stellar streams reveals information about the gravitational potential where they reside and provides important constraints on the properties of dark matter. However, the intrinsic faintness of these streams makes their detection beyond Local environments highly challenging. Here, we report the detection of an extremely faint stellar stream (μg, max = 29.5 mag arcsec-2) with an extraordinarily coherent and thin morphology in the Coma Galaxy Cluster. This Giant Coma Stream spans ∼510 kpc in length and appears as a free-floating structure located at a projected distance of 0.8 Mpc from the center of Coma. We do not identify any potential galaxy remnant or core, and the stream structure appears featureless in our data. We interpret the Giant Coma Stream as being a recently accreted, tidally disrupting passive dwarf. Using the Illustris-TNG50 simulation, we identify a case with similar characteristics, showing that, although rare, these types of streams are predicted to exist in N-CDM. Our work unveils the presence of free-floating, extremely faint and thin stellar streams in galaxy clusters, widening the environmental context in which these objects are found ahead of their promising future application in the study of the properties of dark matter.</p

    A giant thin stellar stream in the Coma Galaxy Cluster

    Get PDF
    The study of dynamically cold stellar streams reveals information about the gravitational potential where they reside and provides important constraints on the properties of dark matter. However, the intrinsic faintness of these streams makes their detection beyond Local environments highly challenging. Here, we report the detection of an extremely faint stellar stream (μg, max = 29.5 mag arcsec-2) with an extraordinarily coherent and thin morphology in the Coma Galaxy Cluster. This Giant Coma Stream spans ∼510 kpc in length and appears as a free-floating structure located at a projected distance of 0.8 Mpc from the center of Coma. We do not identify any potential galaxy remnant or core, and the stream structure appears featureless in our data. We interpret the Giant Coma Stream as being a recently accreted, tidally disrupting passive dwarf. Using the Illustris-TNG50 simulation, we identify a case with similar characteristics, showing that, although rare, these types of streams are predicted to exist in N-CDM. Our work unveils the presence of free-floating, extremely faint and thin stellar streams in galaxy clusters, widening the environmental context in which these objects are found ahead of their promising future application in the study of the properties of dark matter.</p
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