7,221 research outputs found
Using b-tagging to enhance the SUSY reach of the CERN Large Hadron Collider
Assuming that supersymmetry is realized with parameters in the hyperbolic
branch/focus point (HB/FP) region of the minimal supergravity (mSUGRA) model,
we show that by searching for multijet + missing E_T events with tagged b jets
the reach of experiments at the LHC may be extended by as much as 20% from
current projections. The reason for this is that gluino decays to third
generation quarks are enhanced because the lightest neutralino has substantial
higgsino components. Although we were motivated to perform this analysis
because the HB/FP region is compatible with the recent determination of the
relic density of cold dark matter, our considerations may well have a wider
applicability since decays of gluinos to third generation quarks are favoured
in a wide variety of models.Comment: 16 pages, 1 figur
Novel non-invasive adjunctive techniques for early oral cancer diagnosis and oral lesions examination
Oral cancer is a potentially fatal disease with an increasing incidence and an unchanged 5-year mortality rate. Unfortunately, oral cancer is often still late diagnosed, which leads to an increase in the likelihood of functional impairment due to treatment and mortality rate. Definitive diagnosis of oral cancer must be confirmed by scalpel biopsy and histological assessment. However despite its benefits, scalpel biopsy is invasive and it is burdened by a potential morbidity. Furthermore, previous studies have suggested a high degree of intraobserver and interobserver variability regarding the histological evaluation of malignancy. As a consequence, in recent years there has been a growing and persisting demand towards developing new non-invasive, practical diagnostic tools that might facilitate the early detection of oral cancer. The most investigated non-invasive adjunctive techniques are vital staining, autofluorescence, chemiluminescence, narrow band imaging, and exfoliative cytology. Aim of the review is to critically describe these adjunctive aids and, after considering the literature data, an expert opinion on the effectiveness and the possible use of each technique will be provided
The use of sublingual fentanyl for breakthrough pain by using doses proportional to opioid basal regimen.
Abstract
OBJECTIVE:
The aim of this study was to prospectively assess the efficacy and safety of sublingual fentanyl (SLF) in doses proportional to opioid doses used for background analgesia for the treatment of BTP of cancer patients.
METHODS:
A sample of patients admitted to an acute palliative care unit, presenting breakthrough pain (BTP) episodes and receiving stable doses of opioids for background pain was selected to assess the efficacy and safety of SLF used in doses proportional to the basal opioid regimen used for the management of BTP. For each patient, data from four consecutive episodes were collected. For each episode, nurses collected changes in pain intensity and adverse effects when pain got severe (T0), and 5, 10, and 15 minutes after SLF was given (T15).
RESULTS:
Seventy patients were recruited for the study. The mean age was 61.7 (\ub111.5). Forty-one patients were males. A total of 173 episodes of BTP were recorded (mean 2.5 episodes/patient). In 19 events, documentation regarding changes in pain intensity was incomplete. Of the 154 evaluable episodes, 143 were successfully treated (92%). Mean doses of SLF were 637 \ub5g (SD 786), and 51 patients (72.8%) received SLF doses 65800 \ub5g. When compared to younger adult patients, older patients received significantly lower doses of SLF (p < 0.0005) [DOSAGE ERROR CORRECTED], similarly to their lower basal opioid regimen. Pain intensity significantly decreased at T5, 10 and T15 (p < 0.0005). The number of patients with a pain reduction of more than 33% at T5, T10, and T15 were 11, 79, and 137, respectively, and the number of patients with a reduction in pain intensity of more than 50% were 1, 21, 114 at the same intervals, respectively. No differences in changes in pain intensity for gender (p < 0.9) or age (p < 0.85) were observed. No significant changes in the number of patients reporting adverse effects of mild-moderate intensity were reported after SLF administration in comparison with baseline, and no adverse effects severe enough in intensity to require medical intervention were observed. Limitations of this study are represented by the uncontrolled design.
CONCLUSION:
This study suggests that SLF given in doses proportional to the basal opioid regimen for the management of BTP is safe and effective in clinical practice
LHC Reach for Gauge Mediated Supersymmetry Breaking Models Via Prompt Photon Channels
We evaluate the supersymmetry reach of the Large Hadron Collider within the
gauge-mediated low energy supersymmetry breaking framework, assuming that a
neutralino is the second lightest sparticle and that it decays promptly into a
gravitino which escapes detection. We find that the maximum reach is obtained
via a search for inclusive \gamma\gamma+\eslt events coming dominantly from
chargino and neutralino production. Assuming an integrated luminosity of
10~, we find that LHC experiments will be able to probe values of the
model parameter \Lambda \alt 400 TeV, corresponding to
TeV. A measure of the model parameter may be possible from the photon
spectrum.Comment: 10 page Revtex file plus 4 EPS figure
Changes of QTc interval after opioid switching to oral methadone.
Abstract
A consecutive sample of patients who were switched from strong opioids to methadone in a period of 1 year was surveyed. QTc was assessed before switching (T0) and after achieving adequate analgesia and an acceptable level of adverse effects (Ts). Twenty-eight of 33 patients were switched to methadone successfully. The mean initial methadone doses at T0 were 67.1 mg/day (SD \ub180.2, range 12-390). The mean QTc interval at T0 was 400 ms (SD \ub130, range 330-450). The mean QTc interval at Ts (median 5 days) was 430 ms (SD \ub126, range 390-500). The difference (7.7 %) was significant (p\u2009<\u20090.0005). Only two patients had a QTc of 500 ms. No serious arrhythmia was observed. At the linear regression analysis, there was no significant association between mean opioid doses expressed as oral morphine equivalents and QTc at T0 (p\u2009=\u20090.428), nor between mean methadone doses and QTc at Ts (p\u2009=\u20090.315). No age differences were found with previous opioid doses (p\u2009=\u20090.917), methadone doses (p\u2009=\u20090.613), QTc at T0 (p\u2009=\u20090.173), QTc at Ts (p\u2009=\u20090.297), and final opioid-methadone conversion ratio (p\u2009=\u20090.064). While methadone used for opioids switching seems to be an optimal choice to improve the opioid response in patients poorly responsive to the previous opioid, the possible QTc prolongation should be of concern despite not producing clinical consequences in this group of patients. A larger number of patients should be assessed to quantify the risk of serious arrhythmia
Palliative sedation in patients with advanced cancer followed at home: a prospective study.
Abstract
CONTEXT:
Home care programs in Italy.
OBJECTIVES:
The aim of this study was to assess a protocol for palliative sedation (PS) performed at home.
METHODS:
A total of 219 patients were prospectively assessed to evaluate a PS protocol in patients with advanced cancer followed at home by two home care programs with different territorial facilities. The protocol was based on stepwise administration of midazolam.
RESULTS:
A total of 176 of the patients died at home, and PS was performed in 24 of these patients (13.6%). Younger patients received the procedure more frequently than older patients (P=0.012). The principal reasons to start PS were agitated delirium (n=20) and dyspnea (n=4). Mean duration of PS was 42.2±30.4 hours, and the mean doses of midazolam were 23-58 mg/day. Both the home care team and the patients' relatives expressed optimal or good levels of satisfaction with the procedure in all but one case, respectively.
CONCLUSION:
This protocol for PS was feasible and effective in minimizing distress for a subgroup of patients who died at home. The characteristics of patients who may be effectively sedated at home should be better explored in future studies
Opioid use and effectiveness of its prescription at discharge in an acute pain relief and palliative care unit
The aim of this study was to present how opioids
are used in an acute pain relief and palliative care unit
(APRPCU), where many patients with difficult pain conditions
are admitted from GPs, home palliative care programs,
oncology departments, other hospitals or emergency units,
and other regional places. From a consecutive sample of
cancer patients admitted to an APRPCU for a period of
6 months, patients who had been administered opioids were
included in this survey. Basic information was collected as
well as opioid therapy prescribed at admission and, subsequently,
during admission and at time of discharge. Patients
were discharged once stabilization of pain and symptoms
were obtained and the treatment was considered to be optimized.
One week after being discharged, patients or relatives
were contacted by phone to gather information about
the availability of opioids at dosages prescribed at time of
discharge. One hundred eighty six of 231 patients were
specifically admitted for uncontrolled pain, with a mean
pain intensity of 6.8 (SD 2.5). The mean dose of oral
morphine equivalents in patients receiving opioids before
admission was 45 mg/day (range 10–500 mg). One hundred
seventy five patients (75.7 %) were prescribed around the
clock opioids at admission. About one third of patients
changed treatment (opioid or route). Forty two of 175
(24 %), 27/58 (46.5 %), 10/22 (45.4 %), and 2/4 (50 %)
patients were receiving more than 200 mg of oral morphine
equivalents, as maximum dose of the first, second, third, and
fourth opioid prescriptions, respectively. The pattern of
opioids changed, with the highest doses administered with
subsequent line options. The mean final dose of opioids,
expressed as oral morphine equivalents, for all patients was
318 mg/day (SD 798), that is more than six times the doses
of pre-admission opioid doses. One hundred eighty six
patients (80.5 %) were prescribed a breakthrough cancer
pain (BTcP) medication at admission. Sixty five patients
changed their BTcP prescription, and further 27 patients
changed again. Finally, eight patients were prescribed a
fourth BTcP medication. Of 46 patients available for interview,
the majority of them (n=39, 84 %) did not have
problems with their GPs, who facilitated prescription and
availability of opioids at the dosages prescribed at discharge.
For patients with severe distress, APRPCUs may
guarantee a high-level support to optimize pain and symptom
intensities providing intensive approach and resolving
highly distressing situations in a short time by optimizing
the use of opioids
Diphoton Signals for Large Extra Dimensions at the Tevatron and CERN LHC
We analyze the potentiality of hadron colliders to search for large extra dimensions via the production of photon pairs. The virtual exchange of Kaluza--Klein gravitons can significantly enhance this processes provided the quantum gravity scale () is in the TeV range. We studied in detail the subprocesses and taking into account the complete Standard Model and graviton contributions as well as the unitarity constraints. We show that the Tevatron Run II will be able to probe up to 1.5--1.9 TeV at 2 level, while the LHC can extend this search to 5.3--6.7 TeV, depending on the number of extra dimensions
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