923 research outputs found
Non-Pulmonary Tuberculosis: A Study of 100 Cases of Tuberculosis of Bones, Joints and Glands with Reference to the Type of Bacillus and its Correlation with the Clinical Condition
Probably no disease has been more widely studied than has tuberculosis. From the earliest time in history it would appear to hare been a feature in communal life and its importance may be judged by the number of inquiries and commissions which have had for their object a study of its incidence and natural history. Even at the present time every measure, evolved by individuals and governing bodies to improve the health and general hygiene of the community has in its background the spectre of tuberculosis. The present enquiry deals with 100 consecutive cases who presented lesions which were available for examination, the strain of infecting organism isolated being typed and correlated with the clinical manifestations of the disease. It is not claimed that the investigation is in any way complete. It is hoped, however, that others will undertake further enquiries along similar lines with a view to the understanding of the changes which are taking place in the natural history of the disease at the present tine
Synthesis, structures and cytotoxicity studies of p-sulfonatocalix[4]arene lanthanide complexes
A number of p-sulfonatocalix[4]arene complexes of the lanthanides (Tb, Gd, and Eu) have been prepared, some in the presence of tetraazamacrocycle 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (DO3A), and fully characterised. Crystal structure determinations reveal lanthanide coordination at the sulfonate group, bridging several calixarene units, giving coordination polymers. All complexes in this study have been determined to be relatively non-toxic using in vitro cell assays with CC₅₀ values in the range 30–170 μM
Remote Near-IR Reflectance Measurements with the Use of a Pair of Optical Fibers and a Fourier Transform Spectrometer
Determination of Physical Properties of Reaction-Injection-Molded Polyurethanes by NIR-FT-Raman Spectroscopy
Simultaneous Chandra and VLA Observations of the Transitional Millisecond Pulsar PSR J1023+0038: Anti-correlated X-Ray and Radio Variability
We present coordinated Chandra X-ray Observatory and Karl G. Jansky Very Large Array observations of the transitional millisecond pulsar PSR J1023+0038 in its low-luminosity accreting state. The unprecedented five hours of strictly simultaneous X-ray and radio continuum coverage for the first time unambiguously show a highly reproducible, anti-correlated variability pattern. The characteristic switches from the X-ray high mode into a low mode are always accompanied by a radio brightening with a duration that closely matches the X-ray low mode interval. This behavior cannot be explained by a canonical inflow/outflow accretion model where the radiated emission and the jet luminosity are powered by, and positively correlated with, the available accretion energy. We interpret this phenomenology as alternating episodes of low-level accretion onto the neutron star during the X-ray high mode that are interrupted by rapid ejections of plasma by the active rotation-powered pulsar, possibly initiated by a reconfiguration of the pulsar magnetosphere, that cause a transition to a less X-ray luminous mode. The observed anti-correlation between radio and X-ray luminosity has an additional consequence: transitional MSPs can make excursions into a region of the radio/X-ray luminosity plane previously thought to be occupied solely by black hole X-ray binary sources. This complicates the use of this luminosity relation for identifying candidate black holes, suggesting the need for additional discriminants when attempting to establish the true nature of the accretor
Synthesis, structure, and cytotoxicity studies of oxidovanadium(IV and V) complexes bearing chelating phenolates
The interaction of [VO(acac)2] with 2,6-bis(hydroxymethyl)-4-methylphenol (L1H3) or 6,6/-methylenebis(4-tert-butyl-2-(hydroxymethyl)phenol) (L2H4) in refluxing toluene afforded, following work-up in ethanol, the complexes [VOL1]2 (1) and {[VO(acac)(HOEt)](VO)L2]}2 (2), respectively. Use of 4-[3,5-bis(2-hydroxyphenyl)-1,2,4-triazol-1-yl]benzoic acid (L3H2) or 4-[3,5-bis(2-hydroxyphenyl)-1,2,4-triazol-1-yl]benzosulfonic acid (L4H2) with [VOCl3] in refluxing acetonitrile, followed by methanol and THF work-up, afforded the complexes [Et3NH][VO(OMe)L3]2 (3) and [Et3NH][VO(OMe)L4]2 (4), respectively. The interaction of [VOSO4] and L3H2 in refluxing acetonitrile afforded, with extraction into methanol, the complex [VO(OMe)L3]2 (5). The molecular structures of 2, 3 and 5 have been determined; the structure of 1 has been reported previously. The complexes in this study have been determined to be of low toxicity using in vitro cell assays with 50% cytotoxicity values (CC50) values in the range 56 – 126 µM
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Parks Canada’s adaptation framework and workshop approach: Lessons learned across a diverse series of adaptation workshops
In 2017, the Canadian Parks Council Climate Change Working Group, a team of federal, provincial, and territorial representatives, developed a Climate Change Adaptation Framework for Parks and Protected Areas, guiding practitioners through a simple, effective five-step adaptation process. This framework was adapted by Parks Canada into a two-day adaptation workshop approach, with 11 workshops subsequently held from September 2017 to May 2019 at Parks Canada sites in the Yukon, Quebec, Manitoba, Alberta, Nova Scotia, British Columbia, Newfoundland, and Ontario. Lessons learned from each workshop have been integrated into the approach, with the development of tools and guidance for each phase of the process, and a shareable, visual “placemat” that describes each step of the framework, acting as a map for those navigating the process
Quasi-simultaneous Radio/X-Ray Observations of the Candidate Transitional Millisecond Pulsar 3FGL J1544.6-1125 during its Low-luminosity Accretion-disk State
3FGL J1544.6-1125 is a candidate transitional millisecond pulsar (tMSP).
Similar to the well-established tMSPs - PSR J1023+0038, IGR J18245-2452, and
XSS J12270-4859 -- 3FGL J1544.6-1125 shows -ray emission and discrete
X-ray "low" and "high" modes during its low-luminosity accretion-disk state.
Coordinated radio/X-ray observations of PSR J1023+0038 in its current
low-luminosity accretion-disk state showed rapidly variable radio continuum
emission-possibly originating from a compact, self-absorbed jet, the
"propellering" of accretion material, and/or pulsar moding. 3FGL J1544.6-1125
is currently the only other (candidate) tMSP system in this state, and can be
studied to see whether tMSPs are typically radio-loud compared to other neutron
star binaries. In this work, we present a quasi-simultaneous Very Large Array
and Swift radio/X-ray campaign on 3FGL J1544.6-1125. We detect 10 GHz radio
emission varying in flux density from Jy down to 15
Jy (3 upper limit) at four epochs spanning three weeks. At the
brightest epoch, the radio luminosity is erg s for a quasi-simultaneous X-ray luminosity
erg s (for an assumed distance of 3.8
kpc). These luminosities are close to those of PSR J1023+0038, and the results
strengthen the case that 3FGL J1544.6-1125 is a tMSP showing similar
phenomenology to PSR J1023+0038.Comment: Accepted for publication in the Astrophysical Journa
Unusual glitch activity in the RRAT J1819-1458: an exhausted magnetar?
We present an analysis of regular timing observations of the
high-magnetic-field Rotating Radio Transient (RRAT) J18191458 obtained using
the 64-m Parkes and 76-m Lovell radio telescopes over the past five years.
During this time, the RRAT has suffered two significant glitches with
fractional frequency changes of and .
Glitches of this magnitude are a phenomenon displayed by both radio pulsars and
magnetars. However, the behaviour of J18191458 following these glitches is
quite different to that which follows glitches in other neutron stars, since
the glitch activity resulted in a significant long-term net decrease in the
slow-down rate. If such glitches occur every 30 years, the spin-down rate, and
by inference the magnetic dipole moment, will drop to zero on a timescale of a
few thousand years. There are also significant increases in the rate of pulse
detection and in the radio pulse energy immediately following the glitches.Comment: accepted for publication in MNRAS, 7 pages, 7 figures, 1 tabl
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