557 research outputs found
Lupus nephritis. Part I. Histopathological classification, activity and chronicity scores
CITATION: Bates, W. D. et al. 1991. Lupus nephritis. Part I. Histopathological classification, activity and chronicity scores. South African Medical Journal, 79:256-259.The original publication is available at http://www.samj.org.zaRenal biopsy has made a major contribution to the understanding and management of patients with lupus nephritis. In a 5-year retrospective study the renal morphology of 55 biopsies from 51 patients with lupus nephritis was classified acccrding to World Health Organisation criteria. In addition, semi-quantitative activity and chronicity scores were documented. The findings were similar to series from other parts of the world. Of the biopsies reviewed, 6 were class II, 13 class III, 32 class IV and 4 class V. In situations of overlap, segmental proliferative features determined the class to which a biopsy specimen was assigned. Twenty-five of the patients, all WHO class IV, showed activity scores in the severe range. Most of the activity score features were common and easily recognised but necrotising angiitis was only seen in 1 patient. Haematoxylin bodies were difficult to document and the nature and value of the haematoxylin body is questioned.Publisher’s versio
Lupus nephritis. Part II. A clinicopathological correlation and study of outcome
CITATION: Halland, A.-M. et al. 1991. Lupus nephritis. Part II. A clinicopathological correlation and study of outcome. South African Medical Journal, 79:260-264.The original publication is available at http://www.samj.org.zaA 5-year retrospective study of lupus nephritis at Tygerberg Hospital was performed in an attempt to document the clinical and histological spectrum of the disease and to study the outcome of the illness. Activity and chronicity scores were used in addition to the World Health Organisation classification system. Of 55 biopsies from 51 patients reviewed, 6 were class II, 13 class III, 32 class IV and 4 class V. There were 19 deaths and in 15 of these the histological classification was IV. Renal failure and infections, often with uncommon pathogens, were the most important causes of death. Serum creatinine values and creatinine clearance at the time of biopsy or follow-up, and hypertension at follow-up showed a significant relationship with outcome. WHO class IV was associated with a poor outcome (P= 0,048) when compared with the other WHO classes combined. Activity scores showed a significant relationship to the outcome (P = 0,018). The anticardiolipin antibodies IgG and IgM were not associated with WHO class or outcome. The study revealed a spectrum of histological results similar to that of other studies, with a high mortality rate, particularly in class IV disease. Poor renal function, persistent hypertension, histological classification IV, and high activity scores were found to be important prognostic indicators.Publisher’s versio
Realization of an Interacting Two-Valley AlAs Bilayer System
By using different widths for two AlAs quantum wells comprising a bilayer
system, we force the X-point conduction-band electrons in the two layers to
occupy valleys with different Fermi contours, electron effective masses, and
g-factors. Since the occupied valleys are at different X-points of the
Brillouin zone, the interlayer tunneling is negligibly small despite the close
electron layer spacing. We demonstrate the realization of this system via
magneto-transport measurements and the observation of a phase-coherent, bilayer
=1 quantum Hall state flanked by a reentrant insulating phase.Comment: 5 page
Mind your language: working with interpreters in healthcare settings and therapeutic encounters
Global mental health and climate change: A geo-psychiatry perspectiv
Climate changes affect planet ecosystems, living beings, humans, including their lives, rights, economy, housing, migration, and both physical and mental health. Geo-psychiatry is a new discipline within the field of psychiatry studying the interface between various geo-political factors including geographical, political, economic, commercial and cultural determinants which affect society and psychiatry: it provides a holistic overview on global issues such as climate changes, poverty, public health and accessibility to health care. It identifies geopolitical factors and their effects at the international and national levels, as well as considers the politics of climate changes and poverty within this context. This paper then introduces the Compassion, Assertive Action, Pragmatism, and Evidence Vulnerability Index (CAPE-VI) as a global foreign policy index: CAPE-VI calculates how foreign aid should be prioritised for countries that are at risk or already considered to be fragile. These countries are characterised by various forms of conflict, disadvantaged by extremes of climate change, poverty, human rights abuses, and suffering from internal warfare or terrorism
Uncoupled excitons in semiconductor microcavities detected in resonant Raman scattering
We present an outgoing resonant Raman-scattering study of a GaAs/AlGaAs based microcavity embedded in a p-i-n junction. The p-i-n junction allows the vertical electric field to be varied, permitting control of exciton-photon detuning and quenching of photoluminescence which otherwise obscures the inelastic light scattering signals. Peaks corresponding to the upper and lower polariton branches are observed in the resonant Raman cross sections, along with a third peak at the energy of uncoupled excitons. This third peak, attributed to disorder activated Raman scattering, provides clear evidence for the existence of uncoupled exciton reservoir states in microcavities in the strong-coupling regime
Effect of deconfinement on resonant transport in quantum wires
The effect of deconfinement due to finite band offsets on transport through
quantum wires with two constrictions is investigated. It is shown that the
increase in resonance linewidth becomes increasingly important as the size is
reduced and ultimately places an upper limit on the energy (temperature) scale
for which resonances may be observed.Comment: 6 pages, 6 postscript files with figures; uses REVTe
Ethnographic perspectives on global mental health
The field of Global Mental Health (GMH) aims to influence mental health policy and practice worldwide, with a focus on human rights and access to care. There have been important achievements, but GMH has also been the focus of scholarly controversies arising from political, cultural and pragmatic critiques. These debates have become increasingly polarized, giving rise to a need for more dialogue and experience-near research to inform theorizing. Ethnography has much to offer in this respect. This paper frames and introduces five articles in the issue of Transcultural Psychiatry that illustrate the role of ethnographic methods in understanding the effects and implications of the field of global mental health on mental health policy and practice. The papers include ethnographies from South Africa, India and Tonga, that show the potential for ethnographic evidence to inform GMH projects. These studies provide nuanced conceptualizations of GMH’s varied manifestations across different settings, the diverse ways that GMH’s achievements can be evaluated, and the connections that can be drawn between locally observed experiences and wider historical, political and social phenomena. Ethnography can provide a basis for constructive dialogue between those engaged in developing and implementing GMH interventions and those critical of some of its approaches
Unusual conductance collapse in one-dimensional quantum structures
We report an unusual insulating state in one-dimensional quantum wires with a
non-uniform confinement potential. The wires consist of a series of closely
spaced split gates in high mobility GaAs/AlGaAs heterostructures. At certain
combinations of wire widths, the conductance abruptly drops over three orders
of magnitude, to zero on a linear scale. Two types of collapse are observed,
one occurring in multi-subband wires in zero magnetic field and one in single
subband wires in an in-plane field. The conductance of the wire in the collapse
region is thermally activated with an energy of the order of 1 K. At low
temperatures, the conductance shows a steep rise beyond a threshold DC
source-drain voltage of order 1 mV, indicative of a gap in the density of
states. Magnetic depopulation measurements show a decrease in the carrier
density with lowering temperature. We discuss these results in the context of
many-body effects such as charge density waves and Wigner crystallization in
quantum wires.Comment: 5 pages, 5 eps figures, revte
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