962 research outputs found
Distributed Smoothed Tree Kernel
In this paper we explore
the possibility to merge the world of
Compositional Distributional Semantic
Models (CDSM) with Tree Kernels
(TK). In particular, we will introduce a
specific tree kernel (smoothed tree kernel,
or STK) and then show that is
possibile to approximate such kernel
with the dot product of two vectors
obtained compositionally from the sentences,
creating in such a way a new
CDSM
RHIC heavy ion operations performance
The Relativistic Heavy Ion Collider (RHIC) completed its fifth year of operation in 2005, colliding copper ion beams with ps=200 GeV/u and 62.4 GeV/u[1]. Previous heavy ion runs have collided gold ions at ps=130 GeV/u, 200 GeV/u, and 62.4 GeV/u[2], and deuterons and gold ions at ps=200 GeV/u[3]. This paper discusses operational performance statistics of this facility, including Cu- Cu delivered luminosity, availability, calendar time spent in physics stores, and time between physics stores. We summarize the major factors affecting operations efficiency, and characterize machine activities between physics stores
Compositional Distributional Semantics Models in Chunk-based Smoothed Tree Kernels
The field of compositional distributional
semantics has proposed very interesting
and reliable models for accounting the
distributional meaning of simple phrases.
These models however tend to disregard
the syntactic structures when they are applied
to larger sentences. In this paper we
propose the chunk-based smoothed tree
kernels (CSTKs) as a way to exploit the
syntactic structures as well as the reliability
of these compositional models for simple
phrases. We experiment with the recognizing
textual entailment datasets. Our
experiments show that our CSTKs perform
better than basic compositional distributional
semantic models (CDSMs) recursively
applied at the sentence level, and
also better than syntactic tree kernels
Stop-and-go kinetics in amyloid fibrillation
Many human diseases are associated with protein aggregation and fibrillation. Using glucagon as a model system for protein fibrillation we show that fibrils grow in an intermittent fashion, with periods of growth followed by long pauses. Remarkably, even if the intrinsic transition rates vary considerably in each experiment, the probability of being in the growing (stopping) state is very close to 1/4 (3/4), suggesting the presence of 4 independent conformations of the fibril tip. We discuss this possibility in terms of existing structural knowledge
Endovascular treatment of lower extremity arteries is associated with an improved outcome in diabetic patients affected by intermittent claudication
BACKGROUND:
Lower extremity peripheral arterial disease (LE-PAD) is a highly prevalent condition among diabetic patients, associated with reduced walking capacity and a high incidence of cardiovascular events. Endovascular revascularization of lower extremities arteries improves walking performance and quality of life of diabetic patients affected by intermittent claudication, but few studies evaluated the impact of revascularization on cardiovascular outcome in this high-risk population. Accordingly, in the present study we evaluated if leg-ischemia resolution by effective lower limbs percutaneous revascularization can also impact cardiovascular outcome in a homogeneous group of diabetic patients affected by intermittent claudication.
METHODS:
236 diabetic patients affected by LE-PAD at stage II of Fontaine's classification, with ankle/brachial index ≤ 0.90 and one or more hemodynamically significant stenosis in at least one artery of the ileo-femoro-popliteal axis were enrolled in the study. According to the Trans-Atlantic Inter Society Consensus II recommendations, 123 (52.1%) underwent percutaneous transluminal angioplasty (PTA group), while 113 (47.9%) underwent conservative medical therapy only (MT group). The incidence of major cardiovascular events (cardiovascular death, myocardial infarction, ischemic stroke, coronary or carotid revascularization) was prospectively analyzed with Kaplan-Meier curves and the risk of developing a cardiovascular event calculated by Cox analyses.
RESULTS:
No baseline difference in cardiovascular risk factors were observed between the PTA and MT groups, except for a lower prevalence of males in PTA group (74.8% vs. 85.8%, p=0.034). Furthermore, patients in the PTA group showed a worse walking capacity as expressed by maximum walking distance (108.7 ± 300.9 vs 378.4 ± 552.3 meters, p<0.001). During a median follow-up of 20 months (12.0-29.0), the incidence of cardiovascular events was markedly lower in patients in the PTA group with respect to patients in the MT group (7.3% vs. 22.1%, p=0.001), and patients of the MT group had at Cox analysis a 3.9 increased risk with respect to PTA group, after adjustment for potential confounding factors (95% CI 1.1-15.3, p=0.049).
CONCLUSIONS:
The present study shows that lower limbs revascularization of diabetic patients affected by intermittent claudication, in addition to improve walking performance, is associated with a reduction in the incidence of future major cardiovascular events
Blocking the formation of radiation–induced breast cancer stem cells
The goal of adjuvant (post-surgery) radiation therapy (RT) for breast cancer (BC) is to eliminate residual cancer cells, leading to better local tumor control and thus improving patient survival. However, radioresistance increases the risk of tumor recurrence and negatively affects survival. Recent evidence shows that breast cancer stem cells (BCSCs) are radiation-resistant and that relatively differentiated BC cells can be reprogrammed into induced BCSCs (iBCSCs) via radiation-induced re-expression of the stemness genes. Here we show that in irradiation (IR)-treated mice bearing syngeneic mammary tumors, IR-induced stemness correlated with increased spontaneous lung metastasis (51.7%). However, IR-induced stemness was blocked by targeting the NF-κB- stemness gene pathway with disulfiram (DSF)and Copper (Cu2+). DSF is an inhibitor of aldehyde dehydrogenase (ALDH) and an FDA-approved drug for treating alcoholism. DSF binds to Cu2+ to form DSF-Cu complexes (DSF/Cu), which act as a potent apoptosis inducer and an effective proteasome inhibitor, which, in turn, inhibits NF-κB activation. Treatment of mice with RT and DSF significantly inhibited mammary primary tumor growth (79.4%) and spontaneous lung metastasis (89.6%) compared to vehicle treated mice. This anti-tumor efficacy was associated with decreased stem cell properties (or stemness) in tumors. We expect that these results will spark clinical investigation of RT and DSF as a novel combinatorial treatment for breast cancer
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P16. Differential susceptibility of human and mouse NK cells to malignant cell-induced abnormalities in autologous combinations: a potential mechanism for the NK cell-based immunotherapy efficacy
Use of statins in lower extremity artery disease: a review
BACKGROUND:
Lower extremity artery disease (LE-PAD) is one of the most common manifestations of atherosclerosis, particularly in elderly patients, and it is related to a high cardiovascular risk.
DESCRIPTION:
It is well established that statin therapy is characterized by crucial benefits on cardiovascular system by limiting atherosclerotic progression and reducing cardiovascular events and mortality. A growing body of evidence support efficacy of statins in LE-PAD due to the ability of both reducing cardiovascular risk and improving walking distance and, hence, quality of life. Consequently, statin therapy should be considered in all LE-PAD patients and new LDL-cholesterol targets should be reached.
CONCLUSIONS:
Our opinion is that statin therapy remains still underutilized or with inadequate dosage, so therapy of LE-PAD patients should be improved to obtain all the demonstrated benefits of statin
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Pancreatic Ductal Adenocarcinoma: Long-Term Survival Does Not Equal Cure
Background: Pancreatic ductal adenocarcinoma represents 90% of pancreatic cancers and is an important cause of cancer death in the United States. Operative resection remains as the only treatment providing prolonged survival, but even after a curative resection, 5-year survival rates are low. Our aim was to identify the prognostic factors for long-term survival after resection of pancreatic ductal adenocarcinoma related to patients, treatments, and tumor biology. Methods: Retrospective review identified 959 patients who underwent resection of their pancreatic adenocarcinoma between February 1985 and December 2010, of whom 499 were resected before November 2006 and represent the cohort we describe in this study. Patient, tumor, and treatment-related variables were assessed for their associations with 5- and 10-year overall survival. Results: Of the 499 patients, 49% were female and median age was 65 years. The majority of patients had stage IIb disease (60%). Actual 5-year survival after resection of pancreatic adenocarcinoma was 19% (95/499), and actual 10-year survival was 10% (33/329). Significant clinicopathologic factors predicting 5- and 10-year survival were negative margins and negative nodal status. Interestingly, 41% (39/95) of long-term survivors had positive nodes and 24% (23/95) had positive margins. Conclusion: Pancreatic ductal adenocarcinoma demonstrates a very heterogeneous biology, but patients with negative resection margins and node negative cancers are more likely to survive 5 years after resection. However, our series demonstrates that the biology of the cancer rather than simple pathologic factors determine a patient's prognosis
Chronic pancreatitis of the pancreatic remnant is an independent risk factor for pancreatic fistula after distal pancreatectomy
Background: There is an ongoing debate about the best closure technique after distal pancreatectomy (DP). The aim of the closure is to prevent the formation of a clinically relevant post-operative pancreatic fistula (POPF). Stapler technique seems to be equal compared with hand-sewn closure of the remnant. For both techniques, a fistula rate of approximately 30% has been reported. Methods: We retrospectively analyzed our DPs between 01/2000 and 12/2010. In all cases, the pancreatic duct was over sewn with a separately stitched ligation of the pancreatic duct (5*0 PDS) followed by a single-stitched hand-sewn closure of the residual pancreatic gland. The POPF was classified according to the criteria of the International Study Group for Pancreatic Fistula (ISGPF). Univariate and multivariate analyses of potential risk factors for the formation of POPF were performed. Indications for operations included cystic tumors (n = 53), neuroendocrine tumors (n = 27), adenocarcinoma (n = 22), chronic pancreatitis (n = 9), metastasis (n = 6), and others (n = 7). Results: During the period, we performed 124 DPs (♀ = 74, ♂ = 50). The mean age was 57.5 years (18–82). The POPF rates according to the ISGPF criteria were: no fistula, 54.8% (n = 68); grade A, 24.2% (n = 30); grade B, 19.3% (n = 24); and grade C, 1.7% (n = 2). Therefore, in 21.0% (n = 26) of the cases, a clinically relevant pancreatic fistula occurred. The mean postoperative stay was significantly higher after grade B/C fistula (26.3 days) compared with no fistula/grade A fistula (13.7 days) (p < 0.05). The uni- and multivariate analyses showed chronic pancreatitis of the pancreatic remnant to be an independent risk factor for the development of POPF (p = 0.004 OR 7.09). Conclusion: By using a standardized hand-sewn closure technique of the pancreatic remnant after DP with separately stitched ligation of the pancreatic duct, a comparably low fistula rate can be achieved. Signs of chronic pancreatitis of the pancreatic remnant may represent a risk factor for the development of a pancreatic fistula after DP and therefore an anastomosis of the remnant to the intestine should be considered
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