244 research outputs found
Limited energy consumption in positioning control of an electropneumatic actuator
International audienceThis paper shows the possibility of using two three-way servo-distributors in place of one five-way for position control of an electropneumatic actuator. Two nonlinear control laws are developed and compared. The aim is to prove the advantage of a multi-input control law in terms of stability and energy consumption due to the flatness property
Strangeness baryon-baryon interactions in relativistic chiral effective field theory
We study the strangeness baryon-baryon interactions in relativistic
chiral effective field theory at leading order. Among the 15 relevant low
energy constants, eight of them are determined by fitting to the state of the
art lattice QCD data of the HAL QCD Collaboration (with MeV), and
the rest are either taken from the study of the hyperon-nucleon systems,
assuming strict SU(3) flavor symmetry, or temporarily set equal to zero. Using
the so-obtained low energy constants, we extrapolate the results to the
physical point, and show that they are consistent with the available
experimental scattering data. Furthermore, we demonstrate that the
and phase shifts near the threshold are very
sensitive to the lattice QCD data fitted, to the pion mass, and to isospin
symmetry breaking effects. As a result, any conclusion drawn from lattice QCD
data at unphysical pion masses (even close to the physical point) should be
taken with caution. Our results at the physical point, similar to the lattice
QCD data, show that a resonance/quasi-bound state may appear in the
/ channel.Comment: 20 pages, 8 figure
Persistence of anticancer activity in berry extracts after simulated gastrointestinal digestion and colonic fermentation
Fruit and vegetable consumption is associated at the population level with a protective effect against colorectal cancer. Phenolic compounds, especially abundant in berries, are of interest due to their putative anticancer activity. After consumption, however, phenolic compounds are subject to digestive conditions within the gastrointestinal tract that alter their structures and potentially their function. However, the majority of phenolic compounds are not efficiently absorbed in the small intestine and a substantial portion pass into the colon. We characterized berry extracts (raspberries, strawberries, blackcurrants) produced by in vitro-simulated upper intestinal tract digestion and subsequent fecal fermentation. These extracts and selected individual colonic metabolites were then evaluated for their putative anticancer activities using in vitro models of colorectal cancer, representing the key stages of initiation, promotion and invasion. Over a physiologically-relevant dose range (0–50 µg/ml gallic acid equivalents), the digested and fermented extracts demonstrated significant anti-genotoxic, anti-mutagenic and anti-invasive activity on colonocytes. This work indicates that phenolic compounds from berries undergo considerable structural modifications during their passage through the gastrointestinal tract but their breakdown products and metabolites retain biological activity and can modulate cellular processes associated with colon cancer
The association of hydration status with physical signs, symptoms and survival in advanced cancer-The use of Bioelectrical Impedance Vector Analysis (BIVA) technology to evaluate fluid volume in palliative care: An observational study
Background
Hydration in advanced cancer is a controversial area; however, current hydration assessments methods are poorly developed. Bioelectrical impedance vector analysis (BIVA) is an accurate hydration tool; however its application in advanced cancer has not been explored. This study used BIVA to evaluate hydration status in advanced cancer to examine the association of fluid status with symptoms, physical signs, renal biochemical measures and survival.
Materials and methods
An observational study of 90 adults with advanced cancer receiving care in a UK specialist palliative care inpatient unit was conducted. Hydration status was assessed using BIVA in addition to assessments of symptoms, physical signs, performance status, renal biochemical measures, oral fluid intake and medications. The association of clinical variables with hydration was evaluated using regression analysis. A survival analysis was conducted to examine the influence of hydration status and renal failure.
Results
The hydration status of participants was normal in 43 (47.8%), 'more hydrated' in 37 (41.1%) and 'less hydrated' in 10 (11.1%). Lower hydration was associated with increased symptom intensity (Beta = -0.29, p = 0.04) and higher scores for physical signs associated with dehydration (Beta = 10.94, p = 0.02). Higher hydration was associated with oedema (Beta = 2.55, p<0.001). Median survival was statistically significantly shorter in 'less hydrated' patients (44 vs. 68 days; p = 0.049) and in pre-renal failure (44 vs. 100 days; p = 0.003).
Conclusions
In advanced cancer, hydration status was associated with clinical signs and symptoms. Hydration status and pre-renal failure were independent predictors of survival. Further studies can establish the utility of BIVA as a standardised hydration assessment tool and explore its potential research application, in order to inform the clinical management of fluid balance in patients with advanced cancer
Oesophageal Metastasis from Colorectal Cancer
Metastasis to the oesophagus is most frequently described in association with lung or breast cancer. Diagnosis is frequently complicated as often only normal tissue is present in endoscopic biopsy specimens. Although oesophagectomy for metastasis has been described, few patients are suitable for curative resection. We report the case of a 62-year-old man who developed an oesophageal metastasis from colorectal cancer and review the available literature
Simulations of fiber flocculation: Effects of fiber properties and interfiber friction
Lipid profiling and oil properties of Camelina sativa seeds engineered to enhance the production of saturated and omega-7 fatty acids
14 Páginas.-- 7 Figuras.-- 3 TablasCamelina sativa is one of the preferred oil crops in plant biotechnology due to its agronomic performance, the quality of its oil and the ease with which it can be transformed. Oils with high levels of saturated fatty acids are in demand for structured lipid elaboration, whereas ω-7 fatty acids like palmitoleic or asclepic acids are of interest for other applications, such as in oleochemistry and biolubricant production. Several strategies have been followed to increase the levels of saturated and ω-7 fatty acids in the camelina plant in this work, including silencing the β-ketoacyl-ACP synthase II (CsKASII) condensing enzyme responsible for the elongation of palmitate to stearate, the expression of exogenous thioesterases, and the overexpression of the endogenous stearoyl-ACP desaturase. The silencing of CsKASII produces an important increase in palmitate in the oil seed, whereas the expression of different alleles of sunflower FatA thioesterases favors the accumulation of both palmitate and stearate. The increase in intraplastidial desaturase activity through CsSAD co-expression forced the desaturation of palmitate, inducing the accumulation of important amounts of ω-7 fatty acids. The phenotypes of the different transformants produced were characterized by profiling the different glycerolipid classes accumulated in their seeds. These oils displayed altered physical properties that were investigated by differential calorimetry studies.We are grateful to Professor Edgar B. Cahoon of the University of Nebraska for providing us with the hpKASII hairpin construct used in this work, as well as some transformation vectors and cloning systems used in this project. We also appreciate the help and knowledge that he gave us to carry out this work. This work was funded by Spanish Ministerio de Ciencia e Innovación and ERDF through the grant AGL2017-83449-R.Peer reviewe
Does an extensive diagnostic workup for upfront resectable pancreatic cancer result in a delay which affects survival? Results from an international multicentre study
Backgrounds/Aims: Pancreatoduodenectomy (PD) is recommended in fit patients with a carcinoma (PDAC) of the pancreatic head, and a delayed resection may affect survival. This study aimed to correlate the time from staging to PD with long-term survival, and study the impact of preoperative investigations (if any) on the timing of surgery.
//
Methods: Data were extracted from the Recurrence After Whipple’s (RAW) study, a multicentre retrospective study of PD outcomes. Only PDAC patients who underwent an upfront resection were included. Patients who received neoadjuvant chemo-/radiotherapy were excluded. Group A (PD within 28 days of most recent preoperative computed tomography [CT]) was compared to group B (> 28 days).
//
Results: A total of 595 patents were included. Compared to group A (median CT-PD time: 12.5 days, interquartile range: 6–21), group B (49 days, 39–64.5) had similar one-year survival (73% vs. 75%, p = 0.6), five-year survival (23% vs. 21%, p = 0.6) and median time-todeath (17 vs. 18 months, p = 0.8). Staging laparoscopy (43 vs. 29.5 days, p = 0.009) and preoperative biliary stenting (39 vs. 20 days, p 0.99) and endoscopic ultrasonography (28 vs. 32 days, p > 0.99) were not.
//
Conclusions: Although a treatment delay may give rise to patient anxiety, our findings would suggest this does not correlate with worse survival. A delay may be necessary to obtain further information and minimize the number of PD patients diagnosed with early disease recurrence
Postoperative complications after pancreatoduodenectomy for malignancy: results from the Recurrence After Whipple's (RAW) study
BACKGROUND: Pancreatoduodenectomy (PD) is associated with significant postoperative morbidity. Surgeons should have a sound understanding of the potential complications for consenting and benchmarking purposes. Furthermore, preoperative identification of high-risk patients can guide patient selection and potentially allow for targeted prehabilitation and/or individualized treatment regimens. Using a large multicentre cohort, this study aimed to calculate the incidence of all PD complications and identify risk factors. METHOD: Data were extracted from the Recurrence After Whipple's (RAW) study, a retrospective cohort study of PD outcomes (29 centres from 8 countries, 2012-2015). The incidence and severity of all complications was recorded and potential risk factors for morbidity, major morbidity (Clavien-Dindo grade > IIIa), postoperative pancreatic fistula (POPF), post-pancreatectomy haemorrhage (PPH) and 90-day mortality were investigated. RESULTS: Among the 1348 included patients, overall morbidity, major morbidity, POPF, PPH and perioperative death affected 53 per cent (n = 720), 17 per cent (n = 228), 8 per cent (n = 108), 6 per cent (n = 84) and 4 per cent (n = 53), respectively. Following multivariable tests, a high BMI (P = 0.007), an ASA grade > II (P II patients were at increased risk of major morbidity (P II was a risk factor for major morbidity and a high BMI was a risk factor for POPF. Patients who are preoperatively identified to be high risk may benefit from targeted prehabilitation or individualized treatment regimens
Predictors of actual five-year survival and recurrence after pancreatoduodenectomy for ampullary adenocarcinoma: results from an international multicentre retrospective cohort study
BACKGROUND:
Pancreatoduodenectomy (PD) is recommended in fit patients with a resectable ampullary adenocarcinoma (AA). We aimed to identify predictors of five-year recurrence/survival.
METHODS:
Data were extracted from the Recurrence After Whipple's (RAW) study, a multicentre retrospective study of PD patients with a confirmed head of pancreas or periampullary malignancy (June 1st, 2012–May 31st, 2015). Patients with AA who developed recurrence/died within five-years were compared to those who did not.
RESULTS:
394 patients were included and actual five-year survival was 54%. Recurrence affected 45% and the median time-to-recurrence was 14 months. Local only, local and distant, and distant only recurrence affected 34, 41 and 94 patients, respectively (site unknown: 7). Among those with recurrence, the most common sites were the liver (32%), local lymph nodes (14%) and lung/pleura (13%). Following multivariable tests, number of resected nodes, histological T stage > II, lymphatic invasion, perineural invasion (PNI), peripancreatic fat invasion (PPFI) and ≥1 positive resection margin correlated with increased recurrence and reduced survival. Furthermore, ≥1 positive margin, PPFI and PNI were all associated with reduced time-to-recurrence.
CONCLUSIONS:
This multicentre retrospective study of PD outcomes identified numerous histopathological predictors of AA recurrence. Patients with these high-risk features might benefit from adjuvant therapy
- …
