583 research outputs found
Pseudo-scalar Higgs boson production at NLO+NLL
We consider the production of a pseudo-scalar particle at the LHC, and
present accurate theoretical predictions for its inclusive cross section in
gluon fusion. The prediction is based on combining fixed-order perturbation
theory and all-order threshold resummation. At fixed order we include the exact
next-to-next-to-leading order (NNLO) plus an approximate
next-to-next-to-next-to-leading order (NLO) which is based on the
recent computation at this order for the scalar case. We then add threshold
resummation at next-to-next-to-next-to leading logarithmic accuracy
(NLL). Various forms of threshold resummation are considered,
differing by the treatment of subleading terms, allowing a robust estimate of
the theoretical uncertainties due to missing higher orders. With particular
attention to pseudo-scalar masses of GeV and GeV, we also observe
that perturbative convergence is much improved when resummation is included.
Additionally, results obtained with threshold resummation in direct QCD are
compared with analogous results as computed in soft-collinear effective theory,
which turn out to be in good agreement. We provide precise predictions for
pseudo-scalar inclusive cross section at TeV LHC for a wide range of
masses. The results are available through updated versions of the public codes
ggHiggs and TROLL.Comment: 14 pages, 7 figures, 1 table. Now includes a more precise assessment
of the uncertainty on the approximate N3LO. Final version accepted by EPJ
Technique of sentinel lymph node biopsy and lymphatic mapping during laparoscopic colon resection for cancer
BACKGROUND: The utility of lymph node mapping to improve staging in colon cancer is still under evaluation. Laparoscopic colectomy for colon cancer has been validated in multi-centric trials. This study assessed the feasibility and technical aspects of lymph node mapping in laparoscopic colectomy for colon cancer.
METHODS: A total of 42 patients with histologically proven colon cancer were studied from January 2006 to September 2007. Exclusion criteria were: advanced disease (clinical stage III), rectal cancer, previous colon resection and contraindication to laparoscopy. Lymph-nodal status was assessed preoperatively by computed tomography (CT) scan and intra-operatively with the aid of laparoscopic ultrasound. Before resection, 2-3 ml of Patent Blue V dye was injected sub-serosally around the tumour. Coloured lymph nodes were marked as sentinel (SN) with metal clips or suture and laparoscopic colectomy with lymphadenectomy completed as normal. In case of failure of the intra-operative procedure, an ex vivo SN biopsy was performed on the colectomy specimen after resection.
RESULTS: A total number of 904 lymph nodes were examined, with a median number of 22 lymph nodes harvested per patient. The SN detection rate was 100%, an ex vivo lymph node mapping was necessary in four patients. Eleven (26.2%) patients had lymph-nodal metastases and in five (45.5%) of these patients, SN was the only positive lymph node. There were two (18.2%) false-negative SN. In three cases (7.1%) with aberrant lymphatic drainage, lymphadenectomy was extended. The accuracy of SN mapping was 95.2% and negative predictive value was 93.9%.
CONCLUSIONS: Laparoscopic lymphatic mapping and SN removal is feasible in laparoscopic colectomy for colon cancer. The ex vivo technique is useful as a salvage technique in case of failure of the intra-operative procedure. Prospective studies are justified to determine the real accuracy and false-negative rate of the technique
The role of carbon capture and storage electricity in attaining 1.5 and 2 °C
The climate targets defined under the Paris agreement of limiting global temperature increase below 1.5 or 2 °C require massive deployment of low-carbon options in the energy mix, which is currently dominated by fossil fuels. Scenarios suggest that Carbon Capture and Storage (CCS) might play a central role in this transformation, but CCS deployment is stagnating and doubts remain about its techno-economic feasibility. In this article, we carry out a throughout assessment of the role of CCS electricity for a variety of temperature targets, from 1.5 to above 4 °C, with particular attention to the lower end of this range. We collect the latest data on CCS economic and technological future prospects to accurately represent several types of CCS plants in the WITCH energy-economy model, We capture uncertainties by means of extensive sensitivity analysis in parameters regarding plants technical aspects, as well as costs and technological progress. Our research suggests that stringent temperature scenarios constrain fossil fuel CCS based deployment, which is maximum for medium policy targets. On the other hand, Biomass CCS, along with renewables, increases with the temperature stringency. Moreover, the relative importance of cost and performance parameters change with the climate target. Cost uncertainty matters in less stringent policy cases, whereas performance matters for lower temperature targets
Symptomatic Uncomplicated Diverticular Disease (SUDD): Practical Guidance and Challenges for Clinical Management
Symptomatic Uncomplicated Diverticular Disease (SUDD) is a syndrome within the diverticular disease spectrum, characterized by local abdominal pain with bowel movement changes but without systemic inflammation. This narrative review reports current knowledge, delivers practical guidance, and reveals challenges for the clinical management of SUDD. A broad and common consensus on the definition of SUDD is still needed. However, it is mainly considered a chronic condition that impairs quality of life (QoL) and is characterized by persistent left lower quadrant abdominal pain with bowel movement changes (eg, diarrhea) and low-grade inflammation (eg, elevated calprotectin) but without systemic inflammation. Age, genetic predisposition, obesity, physical inactivity, low-fiber diet, and smoking are considered risk factors. The pathogenesis of SUDD is not entirely clarified. It seems to result from an interaction between fecal microbiota alterations, neuro-immune enteric interactions, and muscular system dysfunction associated with a low-grade and local inflammatory state. At diagnosis, it is essential to assess baseline clinical and Quality of Life (QoL) scores to evaluate treatment efficacy and, ideally, to enroll patients in cohort studies, clinical trials, or registries. SUDD treatments aim to improve symptoms and QoL, prevent recurrence, and avoid disease progression and complications. An overall healthy lifestyle – physical activity and a high-fiber diet, with a focus on whole grains, fruits, and vegetables – is encouraged. Probiotics could effectively reduce symptoms in patients with SUDD, but their utility is missing adequate evidence. Using Rifaximin plus fiber and Mesalazine offers potential in controlling symptoms in patients with SUDD and might prevent acute diverticulitis. Surgery could be considered in patients with medical treatment failure and persistently impaired QoL. Still, studies with well-defined diagnostic criteria for SUDD that evaluate the safety, QoL, effectiveness, and cost-effectiveness of these interventions using standard scores and comparable outcomes are needed
One sea but many routes to Sail. The early maritime dispersal of Neolithic crops from the Aegean to the western Mediterranean.
This paper explores the first maritime westward expansion of crops across the Adriatic and the northern coast of the western Mediterranean. Starting in Greece at c.6500 cal BC and following the coastline to the Andalusian region of Spain to c.4500 cal BC, the presence of the main cereal, pulse, oil and fibre crops are recorded from 122 sites. Patterns in the distribution of crops are explored through ubiquity scores, correspondence analysis and Simpson's diversity index. Our findings reveal changes in the frequencies of crops as farming regimes developed in Europe, and show how different crops followed unique trajectories. Fluctuations in the diversity of the crop spectrum between defined areas are also evident, and may serve to illustrate how founder effects can explain some of the patterns evident in large-scale spatio-temporal evaluations. Within the broader westward expansion of farming, regionalism and multi-directional maritime networks described through archaeological materials are also visible in the botanical records
Resummation prescriptions and ambiguities in SCET vs. direct QCD: Higgs production as a case study
We perform a comparison of soft-gluon resummation in SCET vs. direct QCD
(dQCD), using Higgs boson production in gluon fusion as a case study, with the
goal of tracing the quantitative impact of each source of difference between
the two approaches. We show that saddle-point methods enable a direct
quantitative comparison despite the fact that the scale which is resummed in
the two approaches is not the same. As a byproduct, we put in one-to-one
analytic correspondence various features of either approach: specifically, we
show how the SCET method for treating the Landau pole can be implemented in
dQCD, and how the resummation of the optimal partonic scale of dQCD can be
implemented in SCET. We conclude that the main quantitative difference comes
from power-suppressed subleading contributions, which could in fact be freely
tuned in either approach, and not really characteristic of either. This
conclusion holds for Higgs production in gluon fusion, but it is in fact
generic for processes with similar kinematics. For Higgs production, everything
else being equal, SCET resummation at NNLL in the Becher-Neubert implementation
leads to essentially no enhancement of the NNLO cross-section, unlike dQCD in
the standard implementation of Catani et al
A case of pulmonary lymphangiomatosis: high resolution computed tomography (HRCT) evaluation and correlation with anatomo-radiological findings
Safety and efficacy of natalizumab in children with multiple sclerosis.
OBJECTIVE: To describe the effect of natalizumab in the treatment of subjects
with active multiple sclerosis (MS) treated before the age of 18 years.
METHODS: Nineteen pediatric subjects with MS (mean age 14.6 +/- 2.2 years, mean
number of attacks 5.2 +/- 1.9 during the pretreatment phase of 27.7 +/- 19.7
months, median pretreatment Expanded Disability Status Scale score [EDSS] 2.5,
range 1.0-5.0) were treated with natalizumab at the dose of 300 mg every 28 days.
After treatment initiation, patients were reassessed clinically every month;
brain MRI was performed at baseline and every 6 months.
RESULTS: Patients received a median number of 15 infusions (range 6-26). A
transient reversible worsening of preexisting symptoms occurred in 1 subject
during and following the first infusion. All the patients remained relapse-free
during the whole follow-up. The median EDSS decreased from 2.5 to 2.0 at the last
visit (p < 0.001). EDSS remained stable in 5 cases, decreased by at least 0.5
point in 6 cases, and decreased by at least 1 point in 8 cases. At baseline, the
mean number of gadolinium-enhancing lesions was 4.1 (range 1-20). During the
follow-up, no gadolinium-enhancing lesions were detected (p = 0.008); 3 patients
developed new T2-visible lesions at month 6 scan but the overall number of T2
lesions remained stable during the subsequent follow-up. Transient and mild side
effects occurred in 8 patients.
CONCLUSIONS: Natalizumab was well-tolerated in all subjects. A strong suppression
of disease activity was observed in all subjects during the follow-up.
Classification of evidence: This study provides Class IV evidence that
natalizumab, 300 mg IV once every 28 days, decreased EDSS scores in pediatric
patients with MS over a mean treatment period of 15.2 months
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