1,358 research outputs found

    Pengaruh Pemanasan pada Proses Pembuatan Ekstrak Kulit Buah Manggis (Garcinia Mangostana Linn) terhadap Aktivitas Antimikroba

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    Telah dilakukan penelitian tentang pengaruh pemanasan pada proses pembuatan ekstrak kulit buah manggis (Garcinia mangostana Linn) terhadap aktivitas antimikroba. Metode yang digunakan adalah metode pemanasan pada proses pembuatan ekstrak kulit buah manggis sedangkan metode cakram kertas dan metode berat kering digunakan pada uji antimikroba. Mikroba yang diuji menggunakan, bakteri Escherichia coli, Staphylococcus aureus, khamir Candida albicans, dan jamur Aspergillus Niger. Metode cakram kertas untuk mengidentifikasi aktivitas antimikroba pada bakteri Escherichia coli, Staphylococcus aureus, khamir Candida albicans, sedangkan metode berat kering digunakan untuk identifikasi aktivitas antimikroba dari jamur Aspergillus Niger. Konsentrasi Hambat Minimum pada metode cakram kertas pada mikroba bakteri Escherichia coli, Staphylococcus aureus, khamir Candida albicans yaitu 5 % (w/v), dengan rata-rata luas zona hambat masing-masing 0,043 cm2, 0,018 cm2, 0,013 cm2. Sedangkan pada jamur Aspergillus Niger pada konsentrasi 0,5% (w/v), dengan berat kering 0,06 gram

    A P-type ATPase importer that discriminates between essential and toxic transition metals

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    Transition metals, although being essential cofactors in many physiological processes, are toxic at elevated concentrations. Among the membrane-embedded transport proteins that maintain appropriate intracellular levels of transition metals are ATP-driven pumps belonging to the P-type ATPase superfamily. These metal transporters may be differentiated according to their substrate specificities, where the majority of pumps can extrude either silver and copper or zinc, cadmium, and lead. In the present report, we have established the substrate specificities of nine previously uncharacterized prokaryotic transition-metal P-type ATPases. We find that all of the newly identified exporters indeed fall into one of the two above-mentioned categories. In addition to these exporters, one importer, Pseudomonas aeruginosa Q9I147, was also identified. This protein, designated HmtA (heavy metal transporter A), exhibited a different substrate recognition profile from the exporters. In vivo metal susceptibility assays, intracellular metal measurements, and transport experiments all suggest that HmtA mediates the uptake of copper and zinc but not of silver, mercury, or cadmium. The substrate selectivity of this importer ensures the high-affinity uptake of essential metals, while avoiding intracellular contamination by their toxic counterparts

    The Isomorphism Relation Between Tree-Automatic Structures

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    An ω\omega-tree-automatic structure is a relational structure whose domain and relations are accepted by Muller or Rabin tree automata. We investigate in this paper the isomorphism problem for ω\omega-tree-automatic structures. We prove first that the isomorphism relation for ω\omega-tree-automatic boolean algebras (respectively, partial orders, rings, commutative rings, non commutative rings, non commutative groups, nilpotent groups of class n >1) is not determined by the axiomatic system ZFC. Then we prove that the isomorphism problem for ω\omega-tree-automatic boolean algebras (respectively, partial orders, rings, commutative rings, non commutative rings, non commutative groups, nilpotent groups of class n >1) is neither a Σ21\Sigma_2^1-set nor a Π21\Pi_2^1-set

    Proteomic responses to gold(III)-toxicity in the bacterium Cupriavidus metallidurans CH34

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    Accepted 11th October 2016The metal-resistant β-proteobacterium Cupriavidus metallidurans drives gold (Au) biomineralisation and the (trans)formation of Au nuggets largely via unknown biochemical processes, ultimately leading to the reductive precipitation of mobile, toxic Au(i/iii)-complexes. In this study proteomic responses of C. metallidurans CH34 to mobile, toxic Au(iii)-chloride are investigated. Cells were grown in the presence of 10 and 50 μM Au(iii)-chloride, 50 μM Cu(ii)-chloride and without additional metals. Differentially expressed proteins were detected by difference gel electrophoresis and identified by liquid chromatography coupled mass spectrometry. Proteins that were more abundant in the presence of Au(iii)-chloride are involved in a range of important cellular functions, e.g., metabolic activities, transcriptional regulation, efflux and metal transport. To identify Au-binding proteins, protein extracts were separated by native 2D gel electrophoresis and Au in protein spots was detected by laser absorption inductively coupled plasma mass spectrometry. A chaperon protein commonly understood to bind copper (Cu), CupC, was identified and shown to bind Au. This indicates that it forms part of a multi-metal detoxification system and suggests that similar/shared detoxification pathways for Au and Cu exist. Overall, this means that C. metallidurans CH34 is able to mollify the toxic effects of cytoplasmic Au(iii) by sequestering this Au-species. This effect may in the future be used to develop CupC-based biosensing capabilities for the in-field detection of Au in exploration samples.Carla M. Zammit, Florian Weiland, Joël Brugger, Benjamin Wade, Lyron Juan Winderbaum, Dietrich H. Nies, Gordon Southam, Peter Hoffmann and Frank Reit

    Development of Human Membrane Transporters: Drug Disposition and Pharmacogenetics

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    Membrane transporters play an essential role in the transport of endogenous and exogenous compounds, and consequently they mediate the uptake, distribution, and excretion of many drugs. The clinical relevance of transporters in drug disposition and their effect in adults have been shown in drug–drug interaction and pharmacogenomic studies. Little is known, however, about the ontogeny of human membrane transporters and their roles in pediatric pharmacotherapy. As they are involved in the transport of endogenous substrates, growth and development may be important determinants of their expression and activity. This review presents an overview of our current knowledge on human membrane transporters in pediatric drug disposition and effect. Existing pharmacokinetic and pharmacogenetic data on membrane substrate drugs frequently used in children are presented and related, where possible, to existing ex vivo data, providing a basis for developmental patterns for individual human membrane transporters. As data for individual transporters are currently still scarce, there is a striking information gap regarding the role of human membrane transporters in drug therapy in children

    New Opportunities, New Responsibilities: Welfare Reform in Wyoming

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    Early experiments with welfare-to-work programs and other welfare reform initiatives had disappointing results, but successful state trial programs since the Family Support Act of 1988 are changing the prevailing wisdom. With evidence that reform can enhance self-sufficiency, many states are embarking on a redefinition of public assistance. Wyoming, a conservative frontier state, is implementing a welfare reform plan that incorporates components shown to be successful elsewhere. In addition to enhanced child support enforcement and workfare, Wyoming welfare reform stresses job preparation, education, and training up to the university level. Degree programs utilize the state\u27s video network and are adapted to the rural context

    Cesium, iodine and tritium in NW Pacific waters - a comparison of the Fukushima impact with global fallout

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    Radionuclide impact of the Fukushima Dai-ichi nuclear power plant accident on the distribution of radionuclides in seawater of the NW Pacific Ocean is compared with global fallout from atmospheric tests of nuclear weapons. Surface and water column samples collected during the <i>Ka'imikai-o-Kanaloa</i> (<i>KOK</i>) international expedition carried out in June 2011 were analyzed for <sup>134</sup>Cs, <sup>137</sup>Cs, <sup>129</sup>I and <sup>3</sup>H. The <sup>137</sup>Cs, <sup>129</sup>I and <sup>3</sup>H levels in surface seawater offshore Fukushima varied between 0.002–3.5 Bq L<sup>−1</sup>, 0.01–0.8 μBq L<sup>−1</sup>, and 0.05–0.15 Bq L<sup>−1</sup>, respectively. At the sampling site about 40 km from the coast, where all three radionuclides were analyzed, the Fukushima impact on the levels of these three radionuclides represents an increase above the global fallout background by factors of about 1000, 50 and 3, respectively. The water column data indicate that the transport of Fukushima-derived radionuclides downward to the depth of 300 m has already occurred. The observed <sup>137</sup>Cs levels in surface waters and in the water column are compared with predictions obtained from the ocean general circulation model, which indicates that the Kuroshio Current acts as a southern boundary for the transport of the radionuclides, which have been transported from the Fukushima coast eastward in the NW Pacific Ocean. The <sup>137</sup>Cs inventory in the water column is estimated to be about 2.2 PBq, what can be regarded as a lower limit of the direct liquid discharges into the sea as the seawater sampling was carried out only in the area from 34 to 37° N, and from 142 to 147° E. About 4.6 GBq of <sup>129</sup>I was deposited in the NW Pacific Ocean, and 2.4–7 GBq of <sup>129</sup>I was directly discharged as liquid wastes into the sea offshore Fukushima. The total amount of <sup>3</sup>H released and deposited over the NW Pacific Ocean was estimated to be 0.1–0.5 PBq. These estimations depend, however, on the evaluation of the total <sup>137</sup>Cs activities released as liquid wastes directly into the sea, which should improve when more data are available. Due to a suitable residence time in the ocean, Fukushima-derived radionuclides will provide useful tracers for isotope oceanography studies on the transport of water masses during the next decades in the NW Pacific Ocean

    Chronic non-specific low back pain - sub-groups or a single mechanism?

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    Copyright 2008 Wand and O'Connell; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Low back pain is a substantial health problem and has subsequently attracted a considerable amount of research. Clinical trials evaluating the efficacy of a variety of interventions for chronic non-specific low back pain indicate limited effectiveness for most commonly applied interventions and approaches. Discussion: Many clinicians challenge the results of clinical trials as they feel that this lack of effectiveness is at odds with their clinical experience of managing patients with back pain. A common explanation for this discrepancy is the perceived heterogeneity of patients with chronic non-specific low back pain. It is felt that the effects of treatment may be diluted by the application of a single intervention to a complex, heterogeneous group with diverse treatment needs. This argument presupposes that current treatment is effective when applied to the correct patient. An alternative perspective is that the clinical trials are correct and current treatments have limited efficacy. Preoccupation with sub-grouping may stifle engagement with this view and it is important that the sub-grouping paradigm is closely examined. This paper argues that there are numerous problems with the sub-grouping approach and that it may not be an important reason for the disappointing results of clinical trials. We propose instead that current treatment may be ineffective because it has been misdirected. Recent evidence that demonstrates changes within the brain in chronic low back pain sufferers raises the possibility that persistent back pain may be a problem of cortical reorganisation and degeneration. This perspective offers interesting insights into the chronic low back pain experience and suggests alternative models of intervention. Summary: The disappointing results of clinical research are commonly explained by the failure of researchers to adequately attend to sub-grouping of the chronic non-specific low back pain population. Alternatively, current approaches may be ineffective and clinicians and researchers may need to radically rethink the nature of the problem and how it should best be managed

    Intracellular sodium changes in cancer cells using a microcavity array-based bioreactor system and sodium triple-quantum mr signal

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    The sodium triple-quantum (TQ) magnetic resonance (MR) signal created by interactions of sodium ions with macromolecules has been demonstrated to be a valuable biomarker for cell viability. The aim of this study was to monitor a cellular response using the sodium TQ signal during inhibition of Na/K-ATPase in living cancer cells (HepG2). The cells were dynamically investigated after exposure to 1 mM ouabain or K+^{+}-free medium for 60 min using an MR-compatible bioreactor system. An improved TQ time proportional phase incrementation (TQTPPI) pulse sequence with almost four times TQ signal-to-noise ratio (SNR) gain allowed for conducting experiments with 12–14 × 106^{6} cells using a 9.4 T MR scanner. During cell intervention experiments, the sodium TQ signal increased to 138.9 ± 4.1% and 183.4 ± 8.9% for 1 mM ouabain (n = 3) and K+^{+}-free medium (n = 3), respectively. During reperfusion with normal medium, the sodium TQ signal further increased to 169.2 ± 5.3% for the ouabain experiment, while it recovered to 128.5 ± 6.8% for the K+^{+}-free experiment. These sodium TQ signal increases agree with an influx of sodium ions during Na/K-ATPase inhibition and hence a reduced cell viability. The improved TQ signal detection combined with this MR-compatible bioreactor system provides a capability to investigate the cellular response of a variety of cells using the sodium TQ MR signal
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