3,130 research outputs found
Calciphylaxis following kidney transplantation: a case report
Introduction: Calciphylaxis occurring after kidney transplantation is rare and rarely reported. It results in chronic non-healing wounds and is associated with a poor prognosis and is often fatal. We present a case of proximal lower limb calciphylaxis that occurred early after kidney transplantation. The patient had no classic associated risk factors. He had previously had a total parathyroidectomy but had normal serum calcium-phosphate product and parathyroid hormone levels. The clinical outcome of this case was favorable and highlights some fundamental issues relating to management.
Case prsentation: A 70-year-old British Caucasian man with end-stage renal failure secondary to IgA nephropathy presented six months post kidney transplantation with cutaneous calciphylaxis lesions involving the medial aspect of the thigh bilaterally.
Conclusion: To the best of our knowledge, this is the first reported case of rapid onset cutaneous calciphylaxis occurring soon after kidney transplantation that was associated with a favorable outcome. Cutaneous calciphylaxis lesions should be promptly managed with meticulous wound care, antimicrobial therapy and the correction of calcium-phosphate product where indicated
Protecting eyewitness evidence: Examining the efficacy of a self-administered interview tool
Given the crucial role of eyewitness evidence, statements should be obtained as soon as possible after an incident. This is not always achieved due to demands on police resources. Two studies trace the development of a new tool, the Self-Administered Interview (SAI), designed to elicit a comprehensive initial statement. In Study 1, SAI participants reported more correct details than participants who provided a free recall account, and performed at the same level as participants given a Cognitive Interview. In Study 2, participants viewed a simulated crime and half recorded their statement using the SAI. After a delay of 1 week, all participants completed a free recall test. SAI participants recalled more correct details in the delayed recall task than control participants
Coherent spinor dynamics in a spin-1 Bose condensate
Collisions in a thermal gas are perceived as random or incoherent as a
consequence of the large numbers of initial and final quantum states accessible
to the system. In a quantum gas, e.g. a Bose-Einstein condensate or a
degenerate Fermi gas, the phase space accessible to low energy collisions is so
restricted that collisions be-come coherent and reversible. Here, we report the
observation of coherent spin-changing collisions in a gas of spin-1 bosons.
Starting with condensates occupying two spin states, a condensate in the third
spin state is coherently and reversibly created by atomic collisions. The
observed dynamics are analogous to Josephson oscillations in weakly connected
superconductors and represent a type of matter-wave four-wave mixing. The
spin-dependent scattering length is determined from these oscillations to be
-1.45(18) Bohr. Finally, we demonstrate coherent control of the evolution of
the system by applying differential phase shifts to the spin states using
magnetic fields.Comment: 19 pages, 3 figure
Curves on Heisenberg invariant quartic surfaces in projective 3-space
This paper is about the family of smooth quartic surfaces that are invariant under the Heisenberg group . For a
very general such surface , we show that the Picard number of is 16 and
determine its Picard group. It turns out that the general Heisenberg invariant
quartic contains 320 smooth conics and that in the very general case, this
collection of conics generates the Picard group.Comment: Updated references, corrected typo
Case report on trial: Do you, Doctor, swear to tell the truth, the whole truth and nothing but the truth?
We are in the era of "evidence based medicine" in which our knowledge is stratified from top to bottom in a hierarchy of evidence. Many in the medical and dental communities highly value randomized clinical trials as the gold standard of care and undervalue clinical reports. The aim of this editorial is to emphasize the benefits of case reports in dental and oral medicine, and encourage those of us who write and read them
A novel formulation technology for baculoviruses protects biopesticide from degradation by ultraviolet radiation
Biopesticides are biological pest control agents that are viewed as safer alternatives to the synthetic chemicals that dominate the global insecticide market. A major constraint on the wider adoption of biopesticides is their susceptibility to the ultraviolet (UV: 290–400 nm) radiation in sunlight, which limits their persistence and efficacy. Here, we describe a novel formulation technology for biopesticides in which the active ingredient (baculovirus) is micro-encapsulated in an ENTOSTAT wax combined with a UV absorbant (titanium dioxide, TiO2). Importantly, this capsule protects the sensitive viral DNA from degrading in sunlight, but dissolves in the alkaline insect gut to release the virus, which then infects and kills the pest. We show, using simulated sunlight, in both laboratory bioassays and trials on cabbage and tomato plants, that this can extend the efficacy of the biopesticide well beyond the few hours of existing virus formulations, potentially increasing the spray interval and/or reducing the need for high application rates. The new formulation has a shelf-life at 30 °C of at least 6 months, which is comparable to standard commercial biopesticides and has no phytotoxic effect on the host plants. Taken together, these findings suggest that the new formulation technology could reduce the costs and increase the efficacy of baculovirus biopesticides, with the potential to make them commercially competitive alternatives to synthetic chemicals
Role of gamma probes in performing minimally invasive parathyroidectomy in patients with primary hyperparathyroidism: optimization of preoperative and intraoperative procedures
OBJECTIVE: In the last decade, surgery of primary hyperparathyroidism (HPT) due to a solitary adenoma has moved on from the traditional wide bilateral neck exploration (BNE) to more limited approaches such as unilateral neck exploration and minimally invasive parathyroidectomy. DESIGN: To define the role of intraoperative gamma probe and injection of a low (99m)Tc-MIBI dose in performing minimally invasive radio-guided surgery (MIRS) in HPT patients with a solitary parathyroid adenoma. METHODS: From September 1999 to July 2002, 214 patients with primary HPT entered the study. All patients were preoperatively investigated by a (99m)Tc-pertechnetate/MIBI subtraction scan and high-resolution neck ultrasound. The intraoperative technique we developed differs from other previously described techniques being based on the injection of a low (37 MBq) MIBI dose in the operating theatre a few minutes before the beginning of intervention. RESULTS: On the basis of scan/ultrasound findings 147 patients were selected for a MIRS and 144 of them (98%) were successfully treated by this approach: a solitary parathyroid adenoma was removed through a small 2-2.5 cm skin incision with a mean operative time of 35 min, and a mean hospital stay of 1.2 days. In the other 67 patients with scan/ultrasound evidence of concomitant nodular goiter (n=45) or multi-gland disease (n=13) or with a negative scan (n=9), the gamma probe was utilized during a traditional BNE. A low 37 MBq MIBI dose proved to be sufficient to perform a MIRS; moreover it delivered to the patient and surgeon a low, negligible, radiation exposure dose. CONCLUSIONS: The combination of a (99m)Tc-pertechnetate/MIBI subtraction scan and neck ultrasound appears to be an accurate imaging protocol in selecting primary HPT patients as candidates for a MIRS. A MIBI dose as low as 37 MBq injected in the operating theatre just before the start of surgery appears to be adequate to perform radio-guided surgery
The secret world of shrimps: polarisation vision at its best
Animal vision spans a great range of complexity, with systems evolving to
detect variations in optical intensity, distribution, colour, and polarisation.
Polarisation vision systems studied to date detect one to four channels of
linear polarisation, combining them in opponent pairs to provide
intensity-independent operation. Circular polarisation vision has never been
seen, and is widely believed to play no part in animal vision. Polarisation is
fully measured via Stokes' parameters--obtained by combined linear and circular
polarisation measurements. Optimal polarisation vision is the ability to see
Stokes' parameters: here we show that the crustacean \emph{Gonodactylus
smithii} measures the exact components required. This vision provides optimal
contrast-enhancement, and precise determination of polarisation with no
confusion-states or neutral-points--significant advantages. We emphasise that
linear and circular polarisation vision are not different modalities--both are
necessary for optimal polarisation vision, regardless of the presence of
strongly linear or circularly polarised features in the animal's environment.Comment: 10 pages, 6 figures, 2 table
Self-Organization, Layered Structure, and Aggregation Enhance Persistence of a Synthetic Biofilm Consortium
Microbial consortia constitute a majority of the earth’s biomass, but little is known about how these cooperating
communities persist despite competition among community members. Theory suggests that non-random spatial structures
contribute to the persistence of mixed communities; when particular structures form, they may provide associated
community members with a growth advantage over unassociated members. If true, this has implications for the rise and
persistence of multi-cellular organisms. However, this theory is difficult to study because we rarely observe initial instances
of non-random physical structure in natural populations. Using two engineered strains of Escherichia coli that constitute a
synthetic symbiotic microbial consortium, we fortuitously observed such spatial self-organization. This consortium forms a
biofilm and, after several days, adopts a defined layered structure that is associated with two unexpected, measurable
growth advantages. First, the consortium cannot successfully colonize a new, downstream environment until it selforganizes
in the initial environment; in other words, the structure enhances the ability of the consortium to survive
environmental disruptions. Second, when the layered structure forms in downstream environments the consortium
accumulates significantly more biomass than it did in the initial environment; in other words, the structure enhances the
global productivity of the consortium. We also observed that the layered structure only assembles in downstream
environments that are colonized by aggregates from a previous, structured community. These results demonstrate roles for
self-organization and aggregation in persistence of multi-cellular communities, and also illustrate a role for the techniques
of synthetic biology in elucidating fundamental biological principles
Perturbative quantum gravity with the Immirzi parameter
We study perturbative quantum gravity in the first-order tetrad formalism.
The lowest order action corresponds to Einstein-Cartan plus a parity-odd term,
and is known in the literature as the Holst action. The coupling constant of
the parity-odd term can be identified with the Immirzi parameter of loop
quantum gravity. We compute the quantum effective action in the one-loop
expansion. As in the metric second-order formulation, we find that in the case
of pure gravity the theory is on-shell finite, and the running of Newton's
constant and the Immirzi parameter is inessential. In the presence of fermions,
the situation changes in two fundamental aspects. First, non-renormalizable
logarithmic divergences appear, as usual. Second, the Immirzi parameter becomes
a priori observable, and we find that it is renormalized by a four-fermion
interaction generated by radiative corrections. We compute its beta function
and discuss possible implications. The sign of the beta function depends on
whether the Immirzi parameter is larger or smaller than one in absolute value,
and the values plus or minus one are UV fixed-points (we work in Euclidean
signature). Finally, we find that the Holst action is stable with respect to
radiative corrections in the case of minimal coupling, up to higher order
non-renormalizable interactions.Comment: v2 minor amendment
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