478 research outputs found
Invasive Streptococcus pyogenes Infections in <3-Month-Old Infants in France: Clinical and Laboratory Features.
Few data are available on invasive group A Streptococcus (GAS) infections (IGASIs) in infants. We described initial clinical and laboratory features and outcomes of <3-month-old infants hospitalized for an IGASI between 2007 and 2016 in France. Patients were identified from the French National Reference Centre for streptococci. IGASI was defined by the isolation of GAS from blood cultures or from other usually sterile sites. Data collection was performed by assessing the patients' hospitalization reports. Twenty-six patients (15 males; 57.7%) were included. Among 19 cases with available data, 14 (73.7%) were household contacts of a GAS infection, reaching 8/9 (88.9%) in neonates. The diagnoses were bacteremia (n = 18; 69.2%), pleural effusion or pneumonia (n = 6; 23.1%), meningitis with brain abscess (n = 1; 3.8%), and septic arthritis (n = 1; 3.8%). Fever (n = 10; 38.5%), hemodynamic disorders (n = 11; 42.3%), respiratory disorders (n = 7; 26.9%), thrombocytopenia (n = 7; 26.9%), and neutropenia (n = 5; 19.2%) were frequently observed. The main emm-genotype was emm-1 (n = 8; 30.8%). Thirteen (50.0%) infants have been admitted to the intensive care unit, and two (7.7%) died. Respiratory disorders, high C-reactive protein level, and the need for transfusion were significantly associated with severity. IGASI remains uncommon in <3-month-old children but leads to a high morbidity. Whether an antibiotic prophylaxis for contact neonates of a patient with GAS infection decreases the risk of infection remains to be determined
Homogeneous redox catalysed reduction of chloromethyldimethylchlorosilane
The electrochemical reduction of chloromethyldimethylchlorosilane, affording 1,1,3,3-tetramethyl-1,3-disilacyclobutane, involves a dissociative electron transfer to the LUMO which contains the predominant contribution of the Si-Cl orbitals, and results in the C-Cl bond cleavage. The reduction of trimethylchlorosilane occurs through the dissociative Si-Cl bond rupture. In the course of the reduction of chloromethyltrimethylsilane, the α-silicon stabilisation of the negative charge makes an individual anion radical to appear on the reaction coordinate. © 1999 Elsevier Science Ltd. All rights reserved
From pelvic radiation to social isolation: a qualitative study of survivors’ experiences of chronic bowel symptoms after pelvic radiotherapy
\ua9 2024, The Author(s).Purpose: We explored survivors’ experiences of chronic bowel symptoms following pelvic radiotherapy, strategies employed in living with these symptoms, effects on daily activities, and roles at home and in the workplace. Methods: Semi-structured interviews were conducted with 28 individuals (10 gynaecological, 14 prostate, four anal/rectal cancer survivors) who had completed pelvic radiotherapy at least six months prior to data collection and who had experience of bowel symptoms during this post-treatment period. Reflexive thematic analysis was undertaken. Results: We propose four themes describing a process leading from experience of symptoms to withdrawal from activities and roles. These are (1) losing control (the experience of unintended anal leakage or discharge); (2) experiencing embarrassment and fear (the experience of embarrassment or fear of embarrassment as a result of discharge becoming public); (3) managing and reacting (acting to reduce the likelihood of discharge or to prevent this becoming public); and (4) restriction and withdrawal (avoiding specific activities or situations so as to reduce or remove the risk of embarrassment). Returning to the workplace presented additional challenges across these themes. Conclusions: Impacts of chronic bowel symptoms can be severe. Survivors employ a variety of methods and strategies in living with their symptoms. Some of these support continued role fulfilment but some constitute a withdrawal from pre-treatment roles. Current healthcare provision and statutory protections fail to fully meet needs following pelvic radiotherapy. Implications for cancer survivors. There is a need to develop and implement evidence-based services and supported self-management programmes for survivors experiencing chronic bowel problems post-radiotherapy
An exact sequence for contact- and symplectic homology
A symplectic manifold with contact type boundary induces
a linearization of the contact homology of with corresponding linearized
contact homology . We establish a Gysin-type exact sequence in which the
symplectic homology of maps to , which in turn maps to
, by a map of degree -2, which then maps to . Furthermore, we
give a description of the degree -2 map in terms of rational holomorphic curves
with constrained asymptotic markers, in the symplectization of .Comment: Final version. Changes for v2: Proof of main theorem supplemented
with detailed discussion of continuation maps. Description of degree -2 map
rewritten with emphasis on asymptotic markers. Sec. 5.2 rewritten with
emphasis on 0-dim. moduli spaces. Transversality discussion reorganized for
clarity (now Remark 9). Various other minor modification
The Geometry of D=11 Killing Spinors
We propose a way to classify all supersymmetric configurations of D=11
supergravity using the G-structures defined by the Killing spinors. We show
that the most general bosonic geometries admitting a Killing spinor have at
least a local SU(5) or an (Spin(7)\ltimes R^8)x R structure, depending on
whether the Killing vector constructed from the Killing spinor is timelike or
null, respectively. In the former case we determine what kind of local SU(5)
structure is present and show that almost all of the form of the geometry is
determined by the structure. We also deduce what further conditions must be
imposed in order that the equations of motion are satisfied. We illustrate the
formalism with some known solutions and also present some new solutions
including a rotating generalisation of the resolved membrane solutions and
generalisations of the recently constructed D=11 Godel solution.Comment: 36 pages. Typos corrected and discussion on G-structures improved.
Final version to appear in JHE
Marginal Deformations of Field Theories with AdS_4 Duals
We generate new AdS_4 solutions of D=11 supergravity starting from AdS_4 x
X_7 solutions where X_7 has U(1)^3 isometry. We consider examples where X_7 is
weak G_2, Sasaki-Einstein or tri-Sasakian, corresponding to d=3 SCFTs with
N=1,2 or 3 supersymmetry, respectively, and where the deformed solutions
preserve N=1,2 or 1 supersymmetry, respectively. For the special cases when X_7
is M(3,2), Q(1,1,1) or N(1,1)_I we identify the exactly marginal deformation in
the dual field theory. We also show that the volume of supersymmetric 5-cycles
of N(1,1)_I agrees with the conformal dimension predicted by the baryons of the
dual field theory.Comment: 28 pages, 2 figures; v2. typos correcte
On BPS preons, generalized holonomies and D=11 supergravities
We develop the BPS preon conjecture to analyze the supersymmetric solutions
of D=11 supergravity. By relating the notions of Killing spinors and BPS
preons, we develop a moving G-frame method (G=GL(32,R), SL(32,R) or Sp(32,R))
to analyze their associated generalized holonomies. As a first application we
derive here the equations determining the generalized holonomies of k/32
supersymmetric solutions and, in particular, those solving the necessary
conditions for the existence of BPS preonic (31/32) solutions of the standard
D=11 supergravity. We also show that there exist elementary preonic solutions,
i.e. solutions preserving 31 out of 32 supersymmetries in a Chern--Simons type
supergravity. We present as well a family of worldvolume actions describing the
motion of pointlike and extended BPS preons in the background of a D'Auria-Fre
type OSp(1|32)-related supergravity model. We discuss the possible implications
for M-theory.Comment: 11 pages, RevTeX Typos corrected, a short note and references adde
The holonomy of the supercovariant connection and Killing spinors
We show that the holonomy of the supercovariant connection for M-theory
backgrounds with Killing spinors reduces to a subgroup of SL(32-N,\bR)\st
(\oplus^N \bR^{32-N}). We use this to give the necessary and sufficient
conditions for a background to admit Killing spinors. We show that there is
no topological obstruction for the existence of up to 22 Killing spinors in
eleven-dimensional spacetime. We investigate the symmetry superalgebras of
supersymmetric backgrounds and find that their structure constants are
determined by an antisymmetric matrix. The Lie subalgebra of bosonic generators
is related to a real form of a symplectic group. We show that there is a
one-one correspondence between certain bases of the Cartan subalgebra of
sl(32, \bR) and supersymmetric planar probe M-brane configurations. A
supersymmetric probe configuration can involve up to 31 linearly independent
planar branes and preserves one supersymmetry. The space of supersymmetric
planar probe M-brane configurations is preserved by an SO(32,\bR) subgroup of
SL(32, \bR).Comment: 27 pages, a key reference was added. v3: minor change
Vacuum interpolation in supergravity via super p-branes
We show that many of the recently proposed supersymmetric p-brane solutions
of d=10 and d=11 supergravity have the property that they interpolate between
Minkowski spacetime and a compactified spacetime, both being supersymmetric
supergravity vacua. Our results imply that the effective worldvolume action for
small fluctuations of the super p-brane is a supersingleton field theory for
, as has been often conjectured in the past.Comment: 8p
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