958 research outputs found
Primary renal leiomyosarcoma: Case report and literature review
Primary leimyosarcoma of the kidney is extremely rare. The management is unclear due to the limited literature on the subject. The diagnosis should be considered when imaging shows a relatively hypovascular tumor involving one renal pole, with atypical features on microscopy. We report a renal leiomyosarcoma in a 68 year old man, who underwent right radical nephrectomy. A tumor-free surgical margin is the most important prognostic factor. Although various modalities of adjuvant treatment have been tried, the overall prognosis is poor as the tumor is highly aggressive
Growth and dislocation studies of β-HMX
Background: The defect structure of organic materials is important as it plays a major role in their crystal growth
properties. It also can play a subcritical role in “hot-spot” detonation processes of energetics and one such
energetic is cyclotetramethylene-tetranitramine, in the commonly used beta form (β-HMX).
Results: The as-grown crystals grown by evaporation from acetone show prismatic, tabular and columnar habits, all
with {011}, {110}, (010) and (101) faces. Etching on (010) surfaces revealed three different types of etch pits, two of
which could be identified with either pure screw or pure edge dislocations, the third is shown to be an artifact of
the twinning process that this material undergoes. Examination of the {011} and {110} surfaces show only one type
of etch pit on each surface; however their natural asymmetry precludes the easy identification of their Burgers
vector or dislocation type. Etching of cleaved {011} surfaces demonstrates that the etch pits can be associated with
line dislocations. All dislocations appear randomly on the crystal surfaces and do not form alignments characteristic
of mechanical deformation by dislocation slip.
Conclusions: Crystals of β-HMX grown from acetone show good morphological agreement with that predicted by
modelling, with three distinct crystal habits observed depending upon the supersaturation of the growth solution.
Prismatic habit was favoured at low supersaturation, while tabular and columnar crystals were predominant at
higher super saturations. The twin plane in β-HMX was identified as a (101) reflection plane. The low plasticity of
β-HMX is shown by the lack of etch pit alignments corresponding to mechanically induced dislocation arrays.
On untwinned {010} faces, two types of dislocations exist, pure edge dislocations with b = [010] and pure screw
dislocations with b = [010]. On twinned (010) faces, a third dislocation type exists and it is proposed that these pits
are associated with pure screw dislocations with b = [010]
Relation between therapeutic response and side effects induced by methylphenidate as observed by parents and teachers of children with ADHD
<p>Abstract</p> <p>Background</p> <p>The desired (therapeutic) and undesired (side) effects of methylphenidate might have underlying correlations. The aim of this study was to explore the strength and the possible sources of these correlations.</p> <p>Methods</p> <p>One hundred and fifty-seven children with ADHD (6-12 years) were administered placebo and methylphenidate (0.5 mg/kg in a divided b.i.d. dose), each for a one-week period, in a double-blind, crossover trial. Therapeutic response was assessed using the Conners' Global Index for parents (CGI-Parents) and teachers (CGI-Teachers), while side effects were assessed using the Barkley Side Effects Rating Scale (SERS).</p> <p>Results</p> <p>The side effect profile as assessed by the SERS was similar to that of previous studies with insomnia, decreased appetite, and headaches showing significant treatment effects (p < 0.005). These "somatic/physical" side effects did not correlate with CGI-Parents or CGI-Teachers. However, the side effects of "irritability", "proneness to crying", and "anxiousness" showed significant relationships with CGI-Parents. These "mood/anxiety" side effects showed no significant correlations with the CGI-Teachers.</p> <p>Conclusion</p> <p>The greater "mood/anxiety" side effects on methylphenidate and placebo, the less the parents observe improvement of their children while treated with methylphenidate. This suggests that the correlations between "mood/anxiety" side effects and poor response to treatment may be driven by observer effects rather than biological commonalities between therapeutic and side effects of methylphenidate.</p
Limits on WWZ and WW\gamma couplings from p\bar{p}\to e\nu jj X events at \sqrt{s} = 1.8 TeV
We present limits on anomalous WWZ and WW-gamma couplings from a search for
WW and WZ production in p-bar p collisions at sqrt(s)=1.8 TeV. We use p-bar p
-> e-nu jjX events recorded with the D0 detector at the Fermilab Tevatron
Collider during the 1992-1995 run. The data sample corresponds to an integrated
luminosity of 96.0+-5.1 pb^(-1). Assuming identical WWZ and WW-gamma coupling
parameters, the 95% CL limits on the CP-conserving couplings are
-0.33<lambda<0.36 (Delta-kappa=0) and -0.43<Delta-kappa<0.59 (lambda=0), for a
form factor scale Lambda = 2.0 TeV. Limits based on other assumptions are also
presented.Comment: 11 pages, 2 figures, 2 table
Search for New Physics in e mu X Data at D0 Using Sleuth: A Quasi-Model-Independent Search Strategy for New Physics
We present a quasi-model-independent search for the physics responsible for
electroweak symmetry breaking. We define final states to be studied, and
construct a rule that identifies a set of relevant variables for any particular
final state. A new algorithm ("Sleuth") searches for regions of excess in those
variables and quantifies the significance of any detected excess. After
demonstrating the sensitivity of the method, we apply it to the semi-inclusive
channel e mu X collected in 108 pb^-1 of ppbar collisions at sqrt(s) = 1.8 TeV
at the D0 experiment during 1992-1996 at the Fermilab Tevatron. We find no
evidence of new high p_T physics in this sample.Comment: 23 pages, 12 figures. Submitted to Physical Review
Search For Heavy Pointlike Dirac Monopoles
We have searched for central production of a pair of photons with high
transverse energies in collisions at TeV using of data collected with the D\O detector at the Fermilab Tevatron in
1994--1996. If they exist, virtual heavy pointlike Dirac monopoles could
rescatter pairs of nearly real photons into this final state via a box diagram.
We observe no excess of events above background, and set lower 95% C.L. limits
of on the mass of a spin 0, 1/2, or 1 Dirac
monopole.Comment: 12 pages, 4 figure
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