Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV

Inclusive transverse momentum spectra of primary charged particles in Pb-Pb collisions at $\sqrt{s_{_{\rm NN}}}$ = 2.76 TeV have been measured by the ALICE Collaboration at the LHC. The data are presented for central and peripheral collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross section. The measured charged particle spectra in $|\eta|<0.8$ and $0.3 < p_T < 20$ GeV/$c$ are compared to the expectation in pp collisions at the same $\sqrt{s_{\rm NN}}$, scaled by the number of underlying nucleon-nucleon collisions. The comparison is expressed in terms of the nuclear modification factor $R_{\rm AA}$. The result indicates only weak medium effects ($R_{\rm AA} \approx$ 0.7) in peripheral collisions. In central collisions, $R_{\rm AA}$ reaches a minimum of about 0.14 at $p_{\rm T}=6$-7GeV/$c$ and increases significantly at larger $p_{\rm T}$. The measured suppression of high-$p_{\rm T}$ particles is stronger than that observed at lower collision energies, indicating that a very dense medium is formed in central Pb-Pb collisions at the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98

Two-pion Bose-Einstein correlations in central Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV at the Large Hadron Collider is presented. We observe a growing trend with energy now not only for the longitudinal and the outward but also for the sideward pion source radius. The pion homogeneity volume and the decoupling time are significantly larger than those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/388

Intra-nasal midazolam in conscious sedation of young pediatric dental patients.

OBJECTIVES: To compare the effects of 3 different doses of intra-nasal midazolam in the conscious sedation of young paediatric dental patients and to compare the effectiveness of the sedation in the fasting and non-fasting child. DESIGN: Double blind random controlled trial. SAMPLE AND METHODS: Thirty-eight uncooperative young children aged 2-5 years (mean age 4.02 years) were randomly assigned to one of 3 groups. The groups and the doses of midazolam administered intra-nasally were A: 0.3 mg/kg, B: 0.4 mg/kg, and C: 0.5 mg/kg body weight. Each child in each group had two visits for restorative treatment: one without food (fasting) and the other with soft drink and light food (non-fasting) before treatment. Child behaviour and sedative effects were evaluated using the scoring system of Houpt. The vital signs were monitored continuously using a pulse oximeter and Dinamap machine. RESULTS: There was rapid onset of sedation with the maximal effect between 8 and 15 minutes. This sedation lasted for 25-40 minutes in Groups A and B and for 60 minutes in Group C. Conscious sedation and dental treatment were achieved in 79%, 96% and 100% of the children in Groups A, B and C, respectively. Consistently higher Houpt scores were seen in Groups B and C, with statistically significant differences between Groups A and C, and B and C (Tukey's range test, P < 0.05). There were no significant differences in the general behaviour of the child, the onset and the duration of sedation between the fasting and the non-fasting child (nonparametric ANOVA P > 0.05). All the vital signs were within normal physiological limits and there were no significant adverse effects either with or without fasting. CONCLUSIONS: All 3 doses of intranasal midazolam were effective in modifying the behaviour of the uncooperative child patient to accept dental treatment. This was irrespective of fasting.King Saud Universit

Paediatric conscious sedation: views and experience of specialists in paediatric dentistry

Objectives The objectives were three-fold: to investigate the level of conscious sedation training received prior to and during specialist training in paediatric dentistry; to establish the use of conscious sedation during and following specialisation; and to determine the attitudes of specialists in paediatric dentistry to conscious sedation. Subjects and methods A self-administered postal questionnaire was sent to all specialists in paediatric dentistry registered with the General Dental Council in January 2008. Non-responders were contacted again after a four-week period. Results A response rate of 60% was achieved. Of the 122 respondents, 67 (55%) had received sedation training as an undergraduate; 89 (75%) had been trained during specialisation. All respondents performed dental treatment under sedation as a trainee and the majority used nitrous oxide inhalation sedation (NOIS). Over 90% of respondents felt that NOIS should be available to all children, both in appropriate primary care settings and in hospitals. One hundred and twenty-one (99%) respondents thought that all trainees in paediatric dentistry should have sedation training. Conclusions The most popular form of sedation amongst specialists in paediatric dentistry was NOIS. However, some of the respondents felt that children should have access to other forms of sedation in both the primary care and hospital settings. Additional research on other forms of sedation is required to evaluate their effectiveness and safety