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1.
Phys Rev Lett ; 131(4): 041002, 2023 Jul 28.
Article de Anglais | MEDLINE | ID: mdl-37566836

RÉSUMÉ

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9 GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36 GeV/c^{2}, rejecting cross sections above 9.2×10^{-48} cm at the 90% confidence level.

2.
Phys Rev Lett ; 122(13): 131301, 2019 Apr 05.
Article de Anglais | MEDLINE | ID: mdl-31012624

RÉSUMÉ

The scattering of dark matter (DM) particles with sub-GeV masses off nuclei is difficult to detect using liquid xenon-based DM search instruments because the energy transfer during nuclear recoils is smaller than the typical detector threshold. However, the tree-level DM-nucleus scattering diagram can be accompanied by simultaneous emission of a bremsstrahlung photon or a so-called "Migdal" electron. These provide an electron recoil component to the experimental signature at higher energies than the corresponding nuclear recoil. The presence of this signature allows liquid xenon detectors to use both the scintillation and the ionization signals in the analysis where the nuclear recoil signal would not be otherwise visible. We report constraints on spin-independent DM-nucleon scattering for DM particles with masses of 0.4-5 GeV/c^{2} using 1.4×10^{4} kg day of search exposure from the 2013 data from the Large Underground Xenon (LUX) experiment for four different classes of mediators. This analysis extends the reach of liquid xenon-based DM search instruments to lower DM masses than has been achieved previously.

3.
Phys Rev Lett ; 118(25): 251302, 2017 Jun 23.
Article de Anglais | MEDLINE | ID: mdl-28696768

RÉSUMÉ

We present experimental constraints on the spin-dependent WIMP-nucleon elastic cross sections from the total 129.5 kg yr exposure acquired by the Large Underground Xenon experiment (LUX), operating at the Sanford Underground Research Facility in Lead, South Dakota (USA). A profile likelihood ratio analysis allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σ_{n}=1.6×10^{-41} cm^{2} (σ_{p}=5×10^{-40} cm^{2}) at 35 GeV c^{-2}, almost a sixfold improvement over the previous LUX spin-dependent results. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

4.
Phys Rev Lett ; 118(26): 261301, 2017 Jun 30.
Article de Anglais | MEDLINE | ID: mdl-28707937

RÉSUMÉ

The first searches for axions and axionlike particles with the Large Underground Xenon experiment are presented. Under the assumption of an axioelectric interaction in xenon, the coupling constant between axions and electrons g_{Ae} is tested using data collected in 2013 with an exposure totaling 95 live days ×118 kg. A double-sided, profile likelihood ratio statistic test excludes g_{Ae} larger than 3.5×10^{-12} (90% C.L.) for solar axions. Assuming the Dine-Fischler-Srednicki-Zhitnitsky theoretical description, the upper limit in coupling corresponds to an upper limit on axion mass of 0.12 eV/c^{2}, while for the Kim-Shifman-Vainshtein-Zhakharov description masses above 36.6 eV/c^{2} are excluded. For galactic axionlike particles, values of g_{Ae} larger than 4.2×10^{-13} are excluded for particle masses in the range 1-16 keV/c^{2}. These are the most stringent constraints to date for these interactions.

5.
Phys Rev Lett ; 118(2): 021303, 2017 Jan 13.
Article de Anglais | MEDLINE | ID: mdl-28128598

RÉSUMÉ

We report constraints on spin-independent weakly interacting massive particle (WIMP)-nucleon scattering using a 3.35×10^{4} kg day exposure of the Large Underground Xenon (LUX) experiment. A dual-phase xenon time projection chamber with 250 kg of active mass is operated at the Sanford Underground Research Facility under Lead, South Dakota (USA). With roughly fourfold improvement in sensitivity for high WIMP masses relative to our previous results, this search yields no evidence of WIMP nuclear recoils. At a WIMP mass of 50 GeV c^{-2}, WIMP-nucleon spin-independent cross sections above 2.2×10^{-46} cm^{2} are excluded at the 90% confidence level. When combined with the previously reported LUX exposure, this exclusion strengthens to 1.1×10^{-46} cm^{2} at 50 GeV c^{-2}.

6.
Rev Med Interne ; 35(5): 337-40, 2014 May.
Article de Français | MEDLINE | ID: mdl-23773904

RÉSUMÉ

INTRODUCTION: The reactivation of varicella-zoster virus occurs in immunocompromised patients, especially in cases of hematological malignancy. Disseminated reactivation could involve digestive tract with life-threatening condition. CASE REPORT: A 76-year-old woman, with a history of chronic lymphocytic leukemia, presented with left hypochondrium pain, and a vesicular rash with hemorrhagic shock that revealed an hemorrhagic gastritis due to varicella-zoster virus. The literature review identified 28 additional cases of gastrointestinal mucosal damage during reactivation of varicella-zoster virus. Mortality is 40%. We report here the first case in the course of low-grade lymphoid malignancy. CONCLUSION: Acute gastrointestinal symptoms in immunocompromised patients should evoke a varicella-zoster virus reactivation with gastrointestinal involvement. This clinical manifestation, although rare, should not be ignored because of its severity.


Sujet(s)
Gastrite/complications , Hémorragie gastro-intestinale/complications , Zona/complications , Leucémie chronique lymphocytaire à cellules B/complications , Sujet âgé , Femelle , Gastrite/diagnostic , Gastrite/virologie , Hémorragie gastro-intestinale/diagnostic , Hémorragie gastro-intestinale/virologie , Zona/diagnostic , Herpèsvirus humain de type 3/physiologie , Humains , Leucémie chronique lymphocytaire à cellules B/diagnostic , Leucémie chronique lymphocytaire à cellules B/virologie , Activation virale
7.
J Clin Neurosci ; 19(11): 1580-2, 2012 Nov.
Article de Anglais | MEDLINE | ID: mdl-22925419

RÉSUMÉ

We report a 72-year-old patient who developed acute limbic encephalitis initially considered of uncertain aetiology. Detailed information on clinical presentation, MRI appearance, antibody levels, cognitive impairment assessment, treatment and evolution of the patient is reported here. Since the early 2000s, many antibodies implied in central nervous system autoimmune disorders have been identified. Anti-glioma-inactivated 1 (LGI1) antibodies have been recently identified as associated with limbic encephalitis, as was the case in our patient.


Sujet(s)
Anticorps/usage thérapeutique , Tumeurs du cerveau/immunologie , Gliome/immunologie , Immunothérapie/méthodes , Encéphalite limbique/thérapie , Protéines/immunologie , Sujet âgé , Anti-inflammatoires/usage thérapeutique , Troubles de la cognition/étiologie , Troubles de la cognition/psychologie , Électroencéphalographie , Humains , Immunoglobulines par voie veineuse/usage thérapeutique , Protéines et peptides de signalisation intracellulaire , Encéphalite limbique/complications , Encéphalite limbique/psychologie , Imagerie par résonance magnétique , Mâle , Troubles mentaux/étiologie , Méthylprednisolone/usage thérapeutique , Tests neuropsychologiques , Prednisolone/usage thérapeutique , Performance psychomotrice/physiologie , Crises épileptiques/étiologie , Tomodensitométrie
8.
Rev Med Interne ; 30(7): 602-8, 2009 Jul.
Article de Français | MEDLINE | ID: mdl-19303175

RÉSUMÉ

INTRODUCTION: Cat scratch disease is an infectious disease caused by Bartonella henselae. Most of the patients present with a lymphadenopathy associated with a local infection at the site of the cat scratch. Disseminated infection is uncommon. CASE REPORT: We report an immunocompetent 61-year-old woman who presented with a systemic cat scratch disease including a multifocal osteomyelitis. Diagnosis was confirmed by PCR on the adenopathy. A literature review identified 51 other cases of osteomyelitis associated with cat scratch disease, 14 of those confirmed by PCR. CONCLUSION: Bone involvement in cat scratch disease is rare, especially in adults. The diagnosis should be suspected on the basis of patient questioning. The antibiotherapy and the place of surgery are discussed.


Sujet(s)
Maladie des griffes du chat/diagnostic , Ostéomyélite/microbiologie , Animaux , Antibactériens/usage thérapeutique , Bartonella henselae/génétique , Bartonella henselae/isolement et purification , Maladie des griffes du chat/traitement médicamenteux , Chats , ADN bactérien/isolement et purification , Femelle , Humains , Immunocompétence , Adulte d'âge moyen , Ostéomyélite/thérapie
9.
Biol Neonate ; 75(3): 152-9, 1999 Mar.
Article de Anglais | MEDLINE | ID: mdl-9925902

RÉSUMÉ

Cerebrospinal fluid (CSF) levels of 3-methoxy-4-hydroxyphenylglycol, 5-hydroxyindoleacetic acid, homovanillic acid, tryptophan, and gamma-aminobutyric acid were measured using high-performance liquid chromatography in 102 infants during the 1st year of life (preterm and term neonates included). CSF levels are expressed versus corrected age (postnatal days - preterm days) which reflects the stage of maturity of the central nervous system. These results are compared to those obtained in CSF of 53 victims of sudden infant death syndrome (SIDS). All components were significantly higher in SIDS than in the age-matched control group. This increase does not seem to be an artefact related to death. Indeed, under the same conditions concerning postmortem time interval before CSF sampling and analysis, the levels are not significantly higher in infants who died from a known pathology than in living infants. Moreover, in living infants as regards a pathology such as asphyxia or hypoventilation in comparison with SIDS, similar profiles are observed in some neurotransmitters or metabolites. Other studies are necessary to explore further neurotransmission systems in SIDS.


Sujet(s)
Acide homovanillique/liquide cérébrospinal , Acide 5-hydroxy-indole-3-acétique/liquide cérébrospinal , Méthoxyhydroxyphénylglycol/liquide cérébrospinal , Mort subite du nourrisson/liquide cérébrospinal , Tryptophane/liquide cérébrospinal , Acide gamma-amino-butyrique/liquide cérébrospinal , Facteurs âges , Chromatographie en phase liquide à haute performance , Humains , Nourrisson , Nouveau-né , Prématuré/liquide cérébrospinal , Mort subite du nourrisson/étiologie , Mort subite du nourrisson/anatomopathologie
11.
Anesthesiology ; 82(1): 47-52, 1995 Jan.
Article de Anglais | MEDLINE | ID: mdl-7832333

RÉSUMÉ

BACKGROUND: Postoperative nausea and vomiting is a distressing anesthetic complication that may delay discharge after ambulatory surgery. Effective prophylaxis for postoperative nausea and vomiting can be achieved in adults with lower doses of ondansetron, a 5-hydroxytryptamine subtype 3 receptor antagonist, compared with chemotherapy-induced emesis. However, the doses of ondansetron used in preventing postoperative nausea and vomiting in children are based on data from chemotherapy-induced emesis. The dose-related efficacy of intravenous ondansetron in the prophylaxis of postoperative emesis in the pediatric outpatient population was determined. METHODS: In a double-blind, randomized placebo-controlled study, 130 patients (mean age 5.7 +/- 3.4 yr) received placebo, 10, 50, or 100 micrograms/kg ondansetron during a standardized anesthetic. Episodes of postoperative vomiting or retching were recorded. RESULTS: Intravenous ondansetron in a dose of 50 micrograms/kg was more effective than placebo or a dose of 10 micrograms/kg in controlling the incidence and frequency of emesis in the hospital and during the first 24 postoperative hours. Increasing the dose of ondansetron to 100 micrograms/kg intravenously did not significantly reduce the incidence or frequency of emesis compared to 50 micrograms/kg intravenously. CONCLUSIONS: Intravenous ondansetron in a dose of 50 micrograms/kg is as effective as larger doses for the prophylaxis of emesis in children undergoing surgical procedures known to be associated with an increased risk for postoperative nausea and vomiting.


Sujet(s)
Nausée/prévention et contrôle , Ondansétron/pharmacologie , Complications postopératoires/prévention et contrôle , Vomissement/prévention et contrôle , Procédures de chirurgie ambulatoire , Anesthésie générale , Enfant , Enfant d'âge préscolaire , Relation dose-effet des médicaments , Méthode en double aveugle , Femelle , Halothane , Humains , Injections veineuses , Mâle , Protoxyde d'azote , Ondansétron/administration et posologie , Douleur postopératoire/traitement médicamenteux , Prémédication anesthésique
13.
J R Coll Surg Edinb ; 39(6): 350-2, 1994 Dec.
Article de Anglais | MEDLINE | ID: mdl-7869289

RÉSUMÉ

Endoscopic transthoracic sympathectomy currently requires one lung anaesthesia to facilitate access to the thoracic sympathetic chain. This may cause reduced perioperative arterial oxygen saturation. We describe a series of patients in which the collapsed lung is kept partially inflated using continuous positive airway pressure (CPAP) with 100% oxygen. This modification of anaesthetic technique enabled a normal arterial oxygen saturation to be maintained thus preventing operative delays whilst the lung was reinflated to restore adequate oxygen saturation.


Sujet(s)
Ventilation à pression positive , Sympathectomie , Humains , Études rétrospectives , Sympathectomie/méthodes , Thoracoscopie
14.
J Forensic Sci ; 39(3): 650-6, 1994 May.
Article de Anglais | MEDLINE | ID: mdl-8006613

RÉSUMÉ

The authors present six cases of homicide and suicide in which the weapon involved was a handgun using shotshell. The injuries caused are described and the ballistic characteristics of the weapons are studied. Such weapons, which are relatively easy to obtain, are not as innocuous as they may appear, since they may be modified either by changing the barrel or by removal of the device inside the barrel which is intended to prevent the firing of solid slugs.


Sujet(s)
Armes à feu/classification , Plaies par arme à feu/anatomopathologie , Adolescent , Adulte , Femelle , Homicide , Humains , Mâle , Adulte d'âge moyen , Suicide , Plaies par arme à feu/mortalité
18.
Anaesthesia ; 44(7): 555-8, 1989 Jul.
Article de Anglais | MEDLINE | ID: mdl-2672868

RÉSUMÉ

Twenty patients who had abdominal hysterectomy under general anaesthesia were randomly assigned to receive either epidural ketamine (30 mg), or epidural diamorphine (5 mg) peri-operatively and on first request for analgesia. Failure to obtain satisfactory analgesia with one of the agents was treated by epidural administration of the other. Pain was assessed by an independent observer, and by the patient using a visual analogue scale. The mean (SD) pain score on recovery from general anaesthesia, on a scale of 0-4, was 2.9 (1.2) for the ketamine group and 1.0 (1.0) for the diamorphine group (p less than 0.01). The mean (SD) time to first request for analgesia was 272 (206) and 72 (41) minutes in the diamorphine and ketamine groups respectively (p less than 0.01). All patients in the diamorphine group obtained adequate analgesia, but all patients in the ketamine group were changed to epidural diamorphine. Epidural ketamine does not appear to be a sufficiently effective alternative to epidural diamorphine for routine use in postoperative pain.


Sujet(s)
Analgésie péridurale , Héroïne/administration et posologie , Kétamine/administration et posologie , Douleur postopératoire/traitement médicamenteux , Adulte , Sujet âgé , Essais cliniques comme sujet , Méthode en double aveugle , Femelle , Humains , Hystérectomie , Adulte d'âge moyen , Mesure de la douleur , Répartition aléatoire , Facteurs temps
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