2,857 research outputs found
Increased absorption by coarse aerosol particles over the Gangetic–Himalayan region
Each atmospheric aerosol type has distinctive light-absorption
characteristics related to its physical/chemical properties. Climate models
treat black carbon as the main light-absorbing component of carbonaceous
atmospheric aerosols, while absorption by some organic aerosols is also
considered, particularly at ultraviolet wavelengths. Most absorbing aerosols
are assumed to be < 1 ÎĽm in diameter (sub-micron). Here we
present results from a recent field study in India, primarily during the
post-monsoon season (October–November), suggesting the presence of absorbing
aerosols sized 1–10 μm. Absorption due to super-micron-sized
particles was nearly 30% greater than that due to smaller particles.
Periods of increased absorption by larger particles ranged from a week to a
month. Radiative forcing calculations under clear-sky conditions show that
super-micron particles account for nearly 44% of the total
aerosol forcing. The origin of the large aerosols is unknown, but
meteorological conditions indicate that they are of local origin. Such
economic and habitation conditions exist throughout much of the
developing world. Hence, large absorbing particles could be an important
component of the regional-scale atmospheric energy balance
Ligation of the intersphincteric fistula tract (LIFT) to treat anal fistula: early results from a prospective observational study
Ligation of the intersphincteric tract (LIFT), a novel sphincter-saving technique, has been recently described with promising results. Literature data are still scant. In this prospective observational study, we present our experience with this technique
Acute stress impairs sensorimotor gating via the neurosteroid allopregnanolone in the prefrontal cortex
Ample evidence indicates that environmental stress impairs information processing, yet the underlying mechanisms remain partially elusive. We showed that, in several rodent models of psychopathology, the neurosteroid allopregnanolone (AP) reduces the prepulse inhibition (PPI) of the startle, a well-validated index of sensorimotor gating. Since this GABAA receptor activator is synthesized in response to acute stress, we hypothesized its participation in stress-induced PPI deficits. Systemic AP administration reduced PPI in C57BL/6J mice and Long-Evans, but not Sprague-Dawley rats. These effects were reversed by isoallopregnanolone (isoAP), an endogenous AP antagonist, and the GABAA receptor antagonist bicuculline and mimicked by AP infusions in the medial prefrontal cortex (mPFC). Building on these findings, we tested AP's implication in the PPI deficits produced by several complementary regimens of acute and short-term stress (footshock, restraint, predator exposure, and sleep deprivation). PPI was reduced by acute footshock, sleep deprivation as well as the combination of restraint and predator exposure in a time- and intensity-dependent fashion. Acute stress increased AP concentrations in the mPFC, and its detrimental effects on PPI were countered by systemic and intra-mPFC administration of isoAP. These results collectively indicate that acute stress impairs PPI by increasing AP content in the mPFC. The confirmation of these mechanisms across distinct animal models and several acute stressors strongly supports the translational value of these findings and warrants future research on the role of AP in information processing
Role of 0.4% glyceryl trinitrate ointment after haemorrhoidectomy: results of a prospective randomised study
INTRODUCTION: Conventional haemorrhoidectomy (CH) is well known to cause significant post-operative pain and delayed return to daily activities. Both surgical wounds and sphincterial apparatus spasms are likely responsible for the pain. In this study, we evaluated the role of glyceryl trinitrate ointment (GTN) in reducing post-operative pain, ameliorating wound healing and recovery after CH. PATIENTS AND METHODS: Between 01/08 and 12/11, 203 patients with symptomatic haemorrhoids were enrolled in the study and received (103 patients) or not (100 patients) 0.4 % GTN ointment for 6 weeks after surgery. Pain was assessed using a 10-cm linear visual analogue scale (VAS). Data on post-operative pain, wound secretion and bleeding, return to normal activities and complications were recorded. Data were analysed using Fisher's exact and Mann-Whitney tests. RESULTS: GTN-treated group experienced significantly less pain during the first week after surgery (p < 0.0001). This difference was more evident starting from post-operative day 4 (p < 0.0001). A significant higher percentage of untreated patients experienced severe pain (mean VAS score > 7) (10 % vs 31 %). There were significant differences in terms of secretion time (p = 0.0052) and bleeding time (p = 0.02) in favor of GTN. In addition, the duration of itching was less in the GTN group (p = 0.0145). Patients treated with GTN were able to an early return to daily activities compared to untreated (p < 0.0001). Fifteen GTN-treated patients (14.6 %) discontinued the application because of local discomfort and headache. CONCLUSIONS: GTN ointment enhances significantly post-operative recovery, reducing pain in terms of duration and intensity. This effect might be secondary to a faster wound healing expressed by reduced secretion, bleeding and itching time
Prevalence of Defaecatory Disorders in Morbidly Obese Patients Before and After Bariatric Surgery
BACKGROUND: The prevalence of obesity is increasing worldwide and has lately reached epidemic proportions in western countries. Several epidemiological studies have consistently shown that both overweight and obesity are important risk factors for the development of various functional defaecatory disorders (DDs), including faecal incontinence and constipation. However, data on their prevalence as well as effectiveness of bariatric surgery on their correction are scant. The primary objective of this study was to estimate the effect of morbid obesity on DDs in a cohort of patients listed for bariatric surgery. We also evaluated preliminary results of the effects of sleeve gastrectomy on these disorders. PATIENTS AND METHODS: A questionnaire-based study was proposed to morbidly obese patients having bariatric surgery. Data included demographics, past medical, surgical and obstetrics histories, as well as obesity related co-morbidities. Wexner Constipation Score (WCS) and the Faecal Incontinence Severity Index (FISI) questionnaires were used to evaluate constipation and incontinence. For the purpose of this study, we considered clinically relevant a WCS ≥5 and a FISI score ≥10. The same questionnaires were completed at 3 and 6 months follow-up after surgery. RESULTS: A total of 139 patients accepted the study and 68 underwent sleeve gastrectomy and fully satisfied our inclusion criteria with a minimum follow-up of 6 months. Overall, mean body mass index (BMI) at listing was 47 ± 7 kg/m(2) (range 35-67 kg/m(2)). Mean WCS was 4.1 ± 4 (range 0-17), while mean FISI score (expressed as mean±standard deviation) was 9.5 ± 9 (range 0-38). Overall, 58.9% of the patients reported DDs according to the above-mentioned scores. Twenty-eight patients (20%) had WCS ≥5. Thirty-five patients (25%) had a FISI ≥10 while 19 patients (13.7%) reported combined abnormal scores. Overall, DDs were more evident with the increase of obesity grade: Mean BMI decreased significantly from 47 ± 7 to 36 ± 6 and to 29 ± 4 kg/m(2) respectively at 3 and 6 months after surgery (p < 0.0001). According to the BMI decrease, the mean WCS decreased from 3.7 ± 3 to 3.1 ± 4 and to 1.6 ± 3 respectively at 3 and 6 months (p = 0.02). Similarly, the FISI score decreased from 10 ± 8 to 3 ± 4 and to 1 ± 2 respectively at 3 and 6 months (p = 0.0001). CONCLUSIONS: Defaecatory disorders are common in morbidly obese patients. The risk of DDs increases with BMI. Bariatric surgery reduces DDs, mainly faecal incontinence, and these findings correlated with BMI reduction
Performance of the Muon Identification at LHCb
The performance of the muon identification in LHCb is extracted from data
using muons and hadrons produced in J/\psi->\mu\mu, \Lambda->p\pi and
D^{\star}->\pi D0(K\pi) decays. The muon identification procedure is based on
the pattern of hits in the muon chambers. A momentum dependent binary
requirement is used to reduce the probability of hadrons to be misidentified as
muons to the level of 1%, keeping the muon efficiency in the range of 95-98%.
As further refinement, a likelihood is built for the muon and non-muon
hypotheses. Adding a requirement on this likelihood that provides a total muon
efficiency at the level of 93%, the hadron misidentification rates are below
0.6%.Comment: 17 pages, 10 figure
Performance of the LHCb muon system
The performance of the LHCb Muon system and its stability across the full
2010 data taking with LHC running at ps = 7 TeV energy is studied. The
optimization of the detector setting and the time calibration performed with
the first collisions delivered by LHC is described. Particle rates, measured
for the wide range of luminosities and beam operation conditions experienced
during the run, are compared with the values expected from simulation. The
space and time alignment of the detectors, chamber efficiency, time resolution
and cluster size are evaluated. The detector performance is found to be as
expected from specifications or better. Notably the overall efficiency is well
above the design requirementsComment: JINST_015P_1112 201
Performance of the LHCb muon system with cosmic rays
The LHCb Muon system performance is presented using cosmic ray events
collected in 2009. These events allowed to test and optimize the detector
configuration before the LHC start. The space and time alignment and the
measurement of chamber efficiency, time resolution and cluster size are
described in detail. The results are in agreement with the expected detector
performance.Comment: Submitted to JINST and accepte
Hindered nucleoside analogs as antiflaviviridae agents
Abstract
Flaviviridae are an important family of viruses, responsible for widely spread diseases such as dengue and West Nile fever and hepatitis C. Despite the severity of the related diseases, no effective antiviral treatments for infection are available. Following our discovery of adenosine-hindered analogs as potent antiflaviviridae agents, we have continued our investigation on guanosine and inosine derivatives, which were evaluated for activity against BVDV, YFV, DENV, and WNV viruses in cell-based assays. The present study allowed us to identify some newer features that led to improve the antiviral potency (down to the µM range) and to selectively inhibit BVDV and YFV viruses. The molecular modeling results were consistent with the hypothesis that test analogs act as RNA-dependent RNA polymerase (RdRp) inhibitors by interacting with a surface allosteric binding pocket
Measurement of the front-end dead-time of the LHCb muon detector and evaluation of its contribution to the muon detection inefficiency
A method is described which allows to deduce the dead-time of the front-end
electronics of the LHCb muon detector from a series of measurements performed
at different luminosities at a bunch-crossing rate of 20 MHz. The measured
values of the dead-time range from 70 ns to 100 ns. These results allow to
estimate the performance of the muon detector at the future bunch-crossing rate
of 40 MHz and at higher luminosity
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