669 research outputs found
Recent results and future of the NA61/SHINE strong interactions program
NA61/SHINE is a fixed target experiment at the CERN Super-Proton-
Synchrotron. The main goals of the experiment are to discover the critical
point of strongly interacting matter and study the properties of the onset of
deconfnement. In order to reach these goals the collaboration studies hadron
production properties in nucleus-nucleus, proton-proton and proton-nucleus
interactions. In this talk, recent results on particle production in p+p
interactions, as well as Be+Be and Ar+Sc collisions in the SPS energy range are
reviewed. The results are compared with available world data. The future of the
NA61/SHINE scientifc program is also presented
O instante fotográfico: os lugares de memória da cidade do Rio Grande do período de Juscelino Kubistchek
Os anos 1950, mais precisamente os anos do governo de Juscelino Kubistchek de Oliveira (1956-1961) eram marcados pelo desejo e anseio pela urbanização e, consequentemente, modernização. Assim, chega-se a cidade do Rio Grande, localizada no Rio Grande do Sul, e possuindo importância considerável portuária (variando entre a 1ª a 3ª posição brasileira) e industrial. O objetivo principal deste trabalho é compreender como se expressou a visualidade urbana, consequentemente a modernização e urbanização na cidade do Rio Grande. Para isso, serão utilizadas fotografias da cidade, oriundas do estúdio Casa Foto Rio Grande e fotorreportagens do Jornal Rio Grande. A fotografia é um produto da cultura material do momento. Assim, este trabalho, sob a perspectiva da atualidade, é um trabalho de “patrimonialização” daquele instante. Dessa maneira, as imagens, configurações e representações do tempo vivido ou imaginado pertencem ao campo da memória.Sem bols
Development of a Haptic Training Simulation for the Administration of Dental Anaesthesia based upon Accurate Anatomical Data
In the dental curriculum, the initial administration of local anaesthesia injection on live patients is critical and students may experience a high degree of anxiety. Low self-confidence often caused by insufficient knowledge of anatomy has been repeatedly reported as one of the major causes. In this paper, we focus on the development of a haptic training system based upon an accurate anatomical model, which aims to encourage self-paced learning of the practical skills that are required in such procedures and to increase students’ self-confidence. We first present the workflow we have considered to develop an accurate anatomical model of the human head and neck and introduce a Virtual Reality-based application commissioned by NHS Education for Scotland to support the learning of the anatomy in a safe and repeatable manner. Finally, we describe the functionalities of the haptic training system and discuss further developments with regard to existing research outcomes
Nefopam for the prevention of postoperative pain: quantitative systematic review
Nefopam, a centrally acting analgesic, has been used in the surgical setting in many countries since the mid-1970s. However, clinical trials provide contflicting results for its analgesic potency. We performed a systematic search (multiple databases, bibliographies, any language, to January 2008) for randomized, placebo-controlled trials of nefopam for the prevention of postoperative pain. Data were combined using classic methods of meta-analyses and were expressed as weighted mean difference (WMD), relative risk (RR), and number needed to treat/harm (NNT/H) with 95% confidence interval (CI). Nine trials (847 adult patients, 359 received nefopam) were included. Nefopam (cumulative doses, 20-160 mg) was given orally or i.v., as single or multiple doses, or as a continuous infusion. Compared with placebo, cumulative 24 h morphine consumption was decreased with nefopam: WMD −13 mg (95% CI −17.9 to −8.15). Pain intensity at 24 h was also decreased: on a 100 mm visual analogue scale, WMD −11.5 mm (95% CI −15.1 to −7.85). The incidence of tachycardia was increased with nefopam (RR 3.12, 95% CI 1.11-8.79; NNH 7), as was the incidence of sweating (RR 4.92, 95% CI 2.0-12.1; NNH 13). There is limited evidence from the published literature that nefopam may be a useful non-opioid analgesic in surgical patients. The analgesic potency seems to be similar to non-steroidal anti-inflammatory drugs. However, dose responsiveness and adverse effect profile remain unclear, and the role of nefopam as part of multimodal analgesia needs to be established. Data in children are lackin
Benefit and risk of intrathecal morphine without local anaesthetic in patients undergoing major surgery: meta-analysis of randomized trials
Intrathecal morphine without local anaesthetic is often added to a general anaesthetic to prevent pain after major surgery. Quantification of benefit and harm and assessment of dose-response are needed. We performed a meta-analysis of randomized trials testing intrathecal morphine alone (without local anaesthetic) in adults undergoing major surgery under general anaesthesia. Twenty-seven studies (15 cardiac-thoracic, nine abdominal, and three spine surgery) were included; 645 patients received intrathecal morphine (dose-range, 100-4000 µg). Pain intensity at rest was decreased by 2 cm on the 10 cm visual analogue scale up to 4 h after operation and by about 1 cm at 12 and 24 h. Pain intensity on movement was decreased by 2 cm at 12 and 24 h. Opioid requirement was decreased intraoperatively, and up to 48 h after operation. Morphine-sparing at 24 h was significantly greater after abdominal surgery {weighted mean difference, −24.2 mg [95% confidence interval (CI) −29.5 to −19.0]}, compared with cardiac-thoracic surgery [−9.7 mg (95% CI −17.6 to −1.80)]. The incidence of respiratory depression was increased with intrathecal morphine [odds ratio (OR) 7.86 (95% CI 1.54-40.3)], as was the incidence of pruritus [OR 3.85 (95% CI 2.40-6.15)]. There was no evidence of linear dose-responsiveness for any of the beneficial or harmful outcomes. In conclusion, intrathecal morphine decreases pain intensity at rest and on movement up to 24 h after major surgery. Morphine-sparing is more pronounced after abdominal than after cardiac-thoracic surgery. Respiratory depression remains a major safety concer
Plasma Concentrations of Brain-derived Neurotrophic Factor in Patients Undergoing Minor Surgery: A Randomized Controlled Trial
We measured perioperative plasma concentrations of brain-derived neurotrophic factor (BDNF), a major mediator of synaptic plasticity in the central nervous system, in males, 30-65 years old, undergoing lumbar or cervical discotomy. Patients were randomly allocated to a general anesthetic with propofol induction and maintenance or with thiopental induction and isoflurane maintenance. BDNF plasma concentrations were measured before induction (baseline), 15min after induction but before start of surgery, at skin closure, in the post-anesthetic care unit, and 24h postoperatively. Data from 26 patients (13 in each group) were analyzed. At each time point, BDNF plasma concentrations showed large variability. At baseline, concentrations were 631±337 (mean±SD)pgml−1 in the propofol group and were 549±512pgml−1 in the thiopental-isoflurane group (P=0.31). At 15min, concentrations significantly decreased in the propofol group (247±219pgml−1, P=0.0012 compared with baseline) but remained unchanged in the thiopental-isoflurane group (597±471pgml−1, P=0.798 compared with baseline). At skin closure and in the post-anesthetic care unit, concentrations were not different from baseline in both groups. At 24h, concentrations significantly decreased below baseline in both groups (propofol: 232±129pgml−1, P=0.0015; thiopental-isoflurane: 253±250pgml−1, P=0.016). In the propofol group, there was a weak but statistically significant positive correlation (R 2=0.38, P=0.026) between the duration of surgery and BDNF plasma concentrations at skin closure. These data suggest that in males undergoing elective minor surgery, BDNF plasma concentrations show a specific pattern that is influenced by the anesthetic technique and, possibly, by the duration of surger
Propofol 1% versus propofol 2% in children undergoing minor ENT surgery
Background. The induction characteristics of propofol 1% and 2% were compared in children undergoing ENT surgery, in a prospective, randomized, double‐blind study. Methods. One hundred and eight children received propofol 1% (n=55) or 2% (n=53) for induction and maintenance of anaesthesia. For induction, propofol 4mgkg-1 was injected at a constant rate (1200mlh-1), supplemented with alfentanil. Intubating conditions without the use of a neuromuscular blocking agent were scored. Results. Pain on injection occurred in 9% and 21% of patients after propofol 1% and 2%, respectively (P=0.09). Loss of consciousness was more rapid with propofol 2% compared with propofol 1% (47s vs 54s; P=0.02). Spontaneous movements during induction occurred in 22% and 34% (P=0.18), and intubating conditions were satisfactory in 87% and 96% (P=0.19) of children receiving propofol 1% or 2%, respectively. There were no differences between the two groups in respect of haemodynamic changes or adverse events. Conclusions. For the end‐points tested, propofol 1% and propofol 2% are similar for induction of anaesthesia in children undergoing minor ENT surgery. Br J Anaesth 2003: 90: 375-
Bispectral and spectral entropy indices at propofol-induced loss of consciousness in young and elderly patients
Background Bispectral (BIS) and state/response entropy (SE/RE) indices have been widely used to estimate depth of anaesthesia and sedation. In adults, independent of age, adequate and safe depth of anaesthesia for surgery is usually assumed when these indices are between 40 and 60. Since the EEG is changing with increasing age, we investigated the impact of advanced age on BIS, SE, and RE indices during induction. Methods BIS and SE/RE indices were recorded continuously in elderly (≥65 yr) and young (≤40 yr) surgical patients who received propofol until loss of consciousness (LOC) using stepwise increasing effect-site concentrations. LOC was defined as an observer assessment of alertness/sedation score <2, corresponding to the absence of response to mild prodding or shaking. Results We analysed 35 elderly [average age, 78 yr (range, 67-96)] and 34 young [35 (19-40)] patients. At LOC, all indices were significantly higher in elderly compared with young patients: BISLOC, median 70 (range, 58-91) vs 58 (40-70); SELOC, 71 (31-88) vs 55.5 (23-79); and RELOC, 79 (35-96) vs 59 (25-80) (P<0.001 for all comparisons). With all three monitors, only a minority of elderly patients lost consciousness within a 40-60 index range: two (5.7%) with BIS and RE each, and seven (20%) with SE. In young patients, the respective numbers were 20 (58.8%) for BIS, 13 (38.2%) for SE, and nine (26.5%) for RE. Conclusions In adults undergoing propofol induction, BIS, SE, and RE indices at LOC are significantly affected by ag
Ventilation strategies in obese patients undergoing surgery: a quantitative systematic review and meta-analysis†
Background Pathophysiological changes due to obesity may complicate mechanical ventilation during general anaesthesia. The ideal ventilation strategy is expected to optimize gas exchange and pulmonary mechanics and to reduce the risk of respiratory complications. Methods Systematic search (databases, bibliographies, to March 2012, all languages) was performed for randomized trials testing intraoperative ventilation strategies in obese patients (BMI ≥30 kg m−2), and reporting on gas exchange, pulmonary mechanics, or pulmonary complications. Meta-analyses were performed when data from at least three studies or 100 patients could be combined. Results Thirteen studies (505 obese surgical patients) reported on a variety of ventilation strategies: pressure- or volume-controlled ventilation (PCV, VCV), various tidal volumes, and different PEEP or recruitment manoeuvres (RM), and combinations thereof. Definitions and reporting of endpoints were inconsistent. In five trials (182 patients), RM added to PEEP compared with PEEP alone improved intraoperative ratio [weighted mean difference (WMD), 16.2 kPa; 95% confidence interval (CI), 8.0-24.4] and increased respiratory system compliance (WMD, 14 ml cm H2O−1; 95% CI, 8-20). Arterial pressure remained unchanged. In four trials (100 patients) comparing PCV with VCV, there was no difference in ratio, tidal volume, or arterial pressure. Comparison of further ventilation strategies or combination of other outcomes was not feasible. Data on postoperative complications were seldom reported. Conclusions The ideal intraoperative ventilation strategy in obese patients remains obscure. There is some evidence that RM added to PEEP compared with PEEP alone improves intraoperative oxygenation and compliance without adverse effects. There is no evidence of any difference between PCV and VC
An allosteric gating model recapitulates the biophysical properties of IK,L expressed in mouse vestibular Type I hair cells
Type I and Type II hair cells are the sensory receptors of the mammalian vestibular epithelia. Type I hair cells are characterized by their basolateral membrane being enveloped in a single large afferent nerve terminal, named calyx, and by the expression of a low-voltage-activated outward rectifying K(+) current, IK,L . The biophysical properties and molecular profile of IK,L are still largely unknown. By using the patch-clamp whole-cell technique, we examined the voltage- and time-dependent properties of IK,L in Type I hair cells of the mouse semicircular canal. We found that the biophysical properties of IK,L were affected by an unstable K(+) equilibrium potential (Veq K(+) ). Both the outward and inward K(+) currents shifted Veq K(+) consistent with K(+) accumulation or depletion, respectively, in the extracellular space, which we attributed to a residual calyx attached to the basolateral membrane of the hair cells. We therefore optimized the hair cell dissociation protocol in order to isolate mature Type I hair cells without their calyx. In these cells, the uncontaminated IK,L showed a half-activation at -79.6 mV and a steep voltage dependence (2.8 mV). IK,L also showed complex activation and deactivation kinetics, which we faithfully reproduced by an allosteric channel gating scheme where the channel is able to open from all (five) closed states. The "early" open states substantially contribute to IK,L activation at negative voltages. This study provides the first complete description of the "native" biophysical properties of IK,L in adult mouse vestibular Type I hair cells. This article is protected by copyright. All rights reserved
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