646 research outputs found
Activity of Bryophyllum pinnatum S. Kurz extracts on respiratory tract pathogenic bacteria
Ethanol extract of Bryophyllum pinnatum (commonly known as ‘Shuka halinka’ or ‘Karan masallachi’ in Hausa) (BP1) was partitioned into n-hexane, chloroform, ethyl acetate and aqueous methanol soluble fractions and labeled BP1–01, BP1–02, BP1–03 and BP1–04 respectively. These fractions were subjected to antibacterial testing against respiratory tract pathogenic bacteria. The n-hexane soluble fraction showed activity against the selected microorganism with highest on Staphylococcus aureus (12mm), Klebsiella pneumonia (11mm) and Salmonella typhi (08mm); ethyl acetate soluble fraction showed mild activity against Escherichia coli (06mm), Staphylococcus aureus (07mm) and Salmonella typhi (07mm), at 10mg/ml. The n-hexane soluble fraction was subjected to activity guided column chromatography. This leads to isolation of three bioactive compounds: BP1-01-01, BP1-01-33 and BP1-01-65. The activity of this plant’s extracts against the test bacteria coupled with the various phytochemical compounds present in the fractions is a pointer to the plant’s potential as a source of drugs that can be used against respiratory tract pathogens.
Keywords: Bryophyllum pinnatum, respiratory tract pathogens, phytochemical screening, antibacterial activit
SKRINING FITOKIMIA DAN UJI DAYA HAMBAT EKTRAK DAUN JAHE MERAH (Zingiber officinale var rubrum) TERHADAP BAKTERI Staphylococcus Epidermidis DAN Escherichia Coli
Infectious disease is one of the diseases caused by microbes, including bacteria. Staphylococcus epidermidis and Escherichia coli are gram-positive and gram-negative bacteria that cause infectious diseases. The selection of medicinal plants as an alternative solution is an effective way of reducing the resistance of bacteria. Based on the empirical data, herbal plants with antimicrobial potential are red ginger (Zingiber officinale var rubrum). This research aimed to determine the inhibition test on Staphylococcus Epidermidis and Escherichia coli due to phytochemical compounds contained in the leaves of red ginger which serve as an antibacterial. Through this experimental laboratory research, a crude drug was extracted using n-hexane, chloroform, ethyl acetate, and methanol solvent. The phytochemical screening results of n-hexane extract showed that red ginger leaves contain alkaloids and terpenoids; chloroform extract contains alkaloids, steroids, and tannins; ethyl acetate extract contains alkaloids, steroids, flavonoids, and tannins; and the methanol extract contains alkaloids, terpenoids, flavonoids, and tannins. Chloramphenicol and Dimethyl sulfoxide (DMSO) were used as the positive control and negative control respectively. Inhibition test results were obtained from the four n-hexane extracts, chloroform extracts, ethyl acetate extracts, and methanol extracts with three different concentrations.The results obtained the greatest inhibition against Staphylococcus Epidermidis bacteria, namely at a concentration of 20% chlorform extract of red ginger leaves as large as 18,90 mm. Meanwhile, the inhibition of Escherichia Coli is at a concentration of 20% n-hexane extract with an inhibitory power of 17,84 mm inhibition zone that is classified as a strong category to inhibit the growth of bacteria .The results of the One Way ANOVA data analysis (p less than 0.01) with a confidence level of 99%
Characterisation of the Binding Properties of Bacillus Thuringiensis 18 Toxin on Leukaemic Cells
<p>Abstract</p> <p>Background</p> <p>Various strains of <it>Bacillus thuringiensis </it>(Bt) have been found to produce parasporal proteins that are cytotoxic to human cancer cells. This study aims to establish the binding affinity of purified Bt 18 toxin for CEM-SS (T lymphoblastic leukaemia cell line), to determine if competition exists between the toxin and commercial anticancer drugs for the binding site on CEM-SS and to localise the binding site of the toxin on CEM-SS.</p> <p>Methods</p> <p>In homologous competitive binding study, the purified toxin was labelled with biotin and allowed to compete with unlabelled toxin for binding sites on CEM-SS and its dissociation constant (Kd) was determined. Comparisons were made with CCRF-SB, CCRF-HSB-2 and MCF-7. In heterologous competitive binding study, biotinylated toxin competition was determined with two other Bt toxins (crude Btj and crude Bt 22) and anticancer drugs (cisplatin, doxorubicin, etoposide, navelbine and methotrexate). To localise the binding site under the confocal microscope, the biotinylated toxin was tagged with FITC-conjugated streptavidin.</p> <p>Results</p> <p>Homologous competitive binding assays revealed decreasing binding affinity of Bt 18 toxin for CEM-SS, CCRF-SB, and CCRF-HSB-2 with Kd of 8.44 nM, 14.98 nM and 17.71 nM respectively. Kd for MCF-7 was not determined as the inhibitory concentration (IC<sub>50</sub>) was not reached. Heterologous competitive study showed little competition (< 30%) between biotinylated Bt 18 toxin and all test compounds used. Confocal microscopy revealed binding of toxin at the periphery of the cell.</p> <p>Conclusions</p> <p>It was postulated that purified Bt 18 toxin binds on the cell surface of CEM-SS and the mechanism of cell death may differ from that of Btj toxin, Bt 22 toxin and all five anticancer drugs used in this study, since it did not significantly compete with these compounds for the same binding site.</p
Higgs production in CP-violating supersymmetric cascade decays: probing the `open hole' at the Large Hadron Collider
A benchmark CP-violating supersymmetric scenario (known as 'CPX-scenario' in
the literature) is studied in the context of the Large Hadron Collider (LHC).
It is shown that the LHC, with low to moderate accumulated luminosity, will be
able to probe the existing `hole' in the - plane, which
cannot be ruled out by the LEP data. We explore the parameter space with
cascade decay of third generation squarks and gluino with CP-violating decay
branching fractions. We propose a multi-channel analysis to probe this
parameter space some of which are background free at an integrated luminosity
of 5-10 fb. Specially, multi-lepton final states (3\l,\, 4\l and like
sign di-lepton) are almost background free and have reach for the
corresponding signals with very early data of LHC for both 14 TeV and 7 TeV
center of mass energy.Comment: 24 pages, 9 figures, references added as in the journal versio
After the colonial: Tina Rimmer the Borneon artist
James Williamson in his 2nd edition of A Short History of British Expansion (1931) drew his readers attention to the dwindling numbers of European colonials particularly the British colonials in the colonies which numbered 1.5 million in 1921 and then 1.4 million in December 192715. Imperialism was at its closure after the world war and the world was in depression. Those who lived after the war returned home even those who were at the fringes of the British colonies. This article explores the social transformation of post imperial colonials who did not return after imperialism especially in the fringes of non-white former colonies like the North Borneo of Malaysia. The question that begs is the resistance or insistence of the imperial mindset of these colonials who did not return home after imperialism. Since there are few who are still alive to answer this question, the one important respondent that has been identified in this research is Tina Rimmer or Mary Christina Rimmer née Lewin, a much loved Borneo[n] artist who will turn a 100 in August 20171
A Comprehensive Analysis of Electric Dipole Moment Constraints on CP-violating Phases in the MSSM
We analyze the constraints placed on individual, flavor diagonal CP-violating
phases in the minimal supersymmetric extension of the Standard Model (MSSM) by
current experimental bounds on the electric dipole moments (EDMs) of the
neutron, Thallium, and Mercury atoms. We identify the four CP-violating phases
that are individually highly constrained by current EDM bounds, and we explore
how these phases and correlations among them are constrained by current EDM
limits. We also analyze the prospective implications of the next generation of
EDM experiments. We point out that all other CP-violating phases in the MSSM
are not nearly as tightly constrained by limits on the size of EDMs. We
emphasize that a rich set of phenomenological consequences is potentially
associated with these generically large EDM-allowed phases, ranging from B
physics, electroweak baryogenesis, and signals of CP-violation at the CERN
Large Hadron Collider and at future linear colliders. Our numerical study takes
into account the complete set of contributions from one- and two-loop EDMs of
the electron and quarks, one- and two-loop Chromo-EDMs of quarks, the Weinberg
3-gluon operator, and dominant 4-fermion CP-odd operator contributions,
including contributions which are both included and not included yet in the
CPsuperH2.0 package. We also introduce an open-source numerical package, 2LEDM,
which provides the complete set of two-loop electroweak diagrams contributing
to the electric dipole moments of leptons and quarks.Comment: 23 pages, 11 figures; v2: references added, minor change
Bayesian Lasso for Semiparametric Structural Equation Models
There has been great interest in developing nonlinear structural equation models and associated statistical inference procedures, including estimation and model selection methods. In this paper a general semiparametric structural equation model (SSEM) is developed in which the structural equation is composed of nonparametric functions of exogenous latent variables and fixed covariates on a set of latent endogenous variables. A basis representation is used to approximate these nonparametric functions in the structural equation and the Bayesian Lasso method coupled with a Markov Chain Monte Carlo (MCMC) algorithm is used for simultaneous estimation and model selection. The proposed method is illustrated using a simulation study and data from the Affective Dynamics and Individual Differences (ADID) study. Results demonstrate that our method can accurately estimate the unknown parameters and correctly identify the true underlying model
Probing CP Violation with and without Momentum Reconstruction at the LHC
We study the potential to observe CP-violating effects in SUSY cascade decay
chains at the LHC. We consider squark and gluino production followed by
subsequent decays into neutralinos with a three-body leptonic decay in the
final step. Asymmetries composed by triple products of momenta of the final
state particles are sensitive to CP-violating effects. Due to large boosts
these asymmetries can be difficult to observe at a hadron collider. We show
that using all available kinematic information one can reconstruct the decay
chains on an event-by-event basis even in the case of 3-body decays, neutrinos
and LSPs in the final state. We also discuss the most important experimental
effects like major backgrounds and momentum smearing due to finite detector
resolution. We show that with 300 fb of collected data, CP violation may
be discovered at the LHC for a wide range of the phase of the bino mass
parameter .Comment: Version accepted for publication in JHEP. Clarifications added on the
assumptions used for plots. New references adde
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