916 research outputs found
From Davydov solitons to decoherence-free subspaces: self-consistent propagation of coherent-product states
The self-consistent propagation of generalized [coherent-product]
states and of a class of gaussian density matrix generalizations is examined,
at both zero and finite-temperature, for arbitrary interactions between the
localized lattice (electronic or vibronic) excitations and the phonon modes. It
is shown that in all legitimate cases, the evolution of states reduces
to the disentangled evolution of the component states. The
self-consistency conditions for the latter amount to conditions for
decoherence-free propagation, which complement the Davydov soliton
equations in such a way as to lift the nonlinearity of the evolution for the
on-site degrees of freedom. Although it cannot support Davydov solitons, the
coherent-product ansatz does provide a wide class of exact density-matrix
solutions for the joint evolution of the lattice and phonon bath in compatible
systems. Included are solutions for initial states given as a product of a
[largely arbitrary] lattice state and a thermal equilibrium state of the
phonons. It is also shown that external pumping can produce self-consistent
Frohlich-like effects. A few sample cases of coherent, albeit not solitonic,
propagation are briefly discussed.Comment: revtex3, latex2e; 22 pages, no figs.; to appear in Phys.Rev.E
(Nov.2001
Production of n-propyl acetate by reactive distillation : experimental and theoretical study
First steps of the development of a catalytic reactive distillation process for the production
of n-propyl acetate based on experiments and simulations are proposed. The kinetics for homogeneously (sulphuric acid) and heterogeneously (Amberlyst 15) catalysed reaction
were investigated and the constants for a pseudo-homogeneous model are presented. Pilot plant experiments were performed using a homogeneous strong acid catalyst in a packed column. A top-column decanter is used to withdraw the aqueous phase and to reflux the organic phase. Simulation results are in good agreement with experimental data. Thermodynamics nonidealities are taken into account using VLE and LLE NRTL interaction parameters. Alcohol conversion and n-propyl acetate purity may be dramatically increased just by adding to the pilot plant a stripping section in an additional column: six different configurations are identified to achieve such a production. The startup is studied in order to determine the best strategy to achieve steady-state conditions. The strong influence of the composition of the initial charging in the decanter can be seen and an initial charging of the two-phase top product leads to the fastest startup
Trans-arterial chemoembolization as a loco-regional inducer of immunogenic cell death in hepatocellular carcinoma: implications for immunotherapy
Immunotherapy; Liver neoplasmsInmunoterapia; Neoplasias hepáticasImmunoteràpia; Neoplàsies hepàtiquesBackground Modulation of adaptive immunity may underscore the efficacy of trans-arterial chemoembolization (TACE). We evaluated the influence of TACE on T-cell function by phenotypic lymphocyte characterization in samples of patients undergoing surgery with (T+) or without (T-) prior-TACE treatment.
Methods We profiled intratumoral (IT), peritumoral (PT) and non-tumoral (NT) background tissue to evaluate regulatory CD4+/FOXP3+ (T-reg) and immune-exhausted CD8+/PD-1+ T-cells across T+ (n=58) and T− (n=61). We performed targeted transcriptomics and T-cell receptor sequencing in a restricted subset of samples (n=24) evaluated in relationship with the expression of actionable drivers of anti-cancer immunity including PD-L1, indoleamine 2,3 dehydrogenase (IDO-1), cytotoxic T-lymphocyte associated protein 4 (CTLA-4), Lag-3, Tim-3 and CD163.
Results We analyzed 119 patients resected (n=25, 21%) or transplanted (n=94, 79%) for Child-Pugh A (n=65, 55%) and Barcelona Clinic Liver Cancer stage A (n=92, 77%) hepatocellular carcinoma. T+ samples displayed lower IT CD4+/FOXP3+ (p=0.006), CD8+ (p=0.002) and CD8+/PD-1+ and NT CD8+/PD-1+ (p<0.001) compared with T−. Lower IT (p=0.005) and NT CD4+/FOXP3+ (p=0.03) predicted for improved recurrence-free survival. In a subset of samples (n=24), transcriptomic analysis revealed upregulation of a pro-inflammatory response in T+. T+ samples were enriched for IRF2 expression (p=0.01), an interferon-regulated transcription factor implicated in cancer immune-evasion. T-cell clonality and expression of PD-L1, IDO-1, CTLA-4, Lag-3, Tim-3 and CD163 was similar in T+ versus T−.
Conclusions TACE is associated with lower IT density of immune-exhausted effector cytotoxic and T-regs, with significant upregulation of pro-inflammatory pathways. This highlights the pleiotropic effects of TACE in modulating the tumor microenvironment and strengthens the rationale for developing immunotherapy alongside TACE.DJP is supported by grant funding from the Wellcome Trust Strategic Fund (PS3416) and by the Cancer Research UK Postdoctoral bursary (C57701/A26137). AF is supported by grant from Instituto de Salud Carlos III (PI18/00542)
An overview of rice cultivation in Spain and the management of herbicide-resistant weeds
Spain is the second highest rice-producing country in the European Union, with approximately 105, 000 ha used to grow this crop. The major rice-producing regions in Spain are Andalusia, Extremadura, Catalonia, and Valencia, followed by Aragon and Navarre. The main soil texture throughout Spanish rice areas is silty clay loam, with alkaline soils (pH > 7.5)—except in the Extremadura area (pH = 5.5–6)—and a low organic matter content. Water quality in terms of salinity is acceptable, although in some coastal rice areas salinity issues occasionally appear to be a determining factor for high yield achievement. According to a survey carried out on farmers and technicians, the most problematic weeds found in rice crops today in Spain are Echinochloa spp., Leptochloa spp., and Cyperus difformis. Most of the currently authorized herbicides can be classified according to two modes of action: ALS-inhibiting and ACCase-inhibiting. Repeated field applications of herbicides with the same mode of action have resulted in the selection of herbicide-resistant weeds. At present, resistance has been confirmed in different regions of Spain to ALS inhibitors in Echinochloa spp., Leptochloa spp., and Cyperus difformis, and to ACCase inhibitors in Echinochloa spp. and Leptochloa spp. The mechanism of resistance in these species is a mutation in the target site of these herbicides. Several mutations have been found in the ALS gene, both in Echinochloa spp. and Cyperus difformis, distributed in the different rice-growing regions considered in this work. ACCase gene mutations have been mainly found in Leptochloa spp. individuals from Extremadura and Valencia. These different mutations have resulted in different patterns of cross-resistance to ALS- and ACCase-inhibiting herbicides. It is likely that the repeated use of these two modes of action in rice will result in the evolution of more resistant weed populations. The possible availability of new herbicides with alternative modes of action in a short space of time seems very limited, suggesting the need for a more appropriate use of the available alternative strategies (crop rotation, dry sowing, manual weeding, etc.). This work presents a review of the main characteristics of rice cultivation in Spain, emphasizing the current problems in this crop and the management of herbicide-resistant weeds. © 2021 by the authors
The Prognosis of Root Canal Therapy: a 20-year Follow-up Ambispective Cohort Study on 411 Patients With 1169 Endodontically Treated Teeth
PURPOSE To evaluate the 20-year prognosis of endodontically treated/re-treated teeth in a population with multiple patient/tooth/site risk factors, and to investigate the prognostic factors that could predict the long-term outcome of endodontic therapy. MATERIALS AND METHODS This ambispective cohort study included patients who received primary/secondary root canal therapy from 1986 to 1998 performed by a single operator in a private practice. Outcomes measures were: tooth survival; clinical and radiographic success, as assessed by the treating clinician and an independent outcome assessor; and complications, as evaluated 20 years after treatment. Descriptive statisti-cs, life table and Cox regression analyses for survival were fitted. RESULTS Four hundred and eleven patients (59% affected by advanced periodontitis) with 1169 endodontically treated teeth were identified (703 treatment, 466 retreatment). Drop-outs at 20-year follow-up were 128 patients (31.1%) with 388 (33.2%) teeth. Forty teeth (3.4%) in 30 patients experienced endodontic complications, subsequently successfully treated. Clinical and radiographic evaluation revealed: complete clinical success in 542 teeth (69.7%), partial success in 10 (1.3%), partial failure in 75 (9.6%), and failure in 151 (19.4%) (10 extracted for endodontic reasons, 58 due to periodontitis, and 58 vertical fracture). Life table analysis revealed 86% tooth survival at 20-year follow-up. The chance of survival decreased with increasing patient age (P = 0.006). Re-treated teeth had better survival than treated teeth (P = 0.024) Canines and premolars had better chances of survival than incisors (P = 0.002 and P = 0.015, respectively). Teeth treated at two sittings (with intermediate medication) had reduced chances of survival as compared to teeth treated at one sitting (P = 0.027). Teeth treated for the first time for endodontic reasons exhibited a better chance of survival than teeth treated for periodontal and prosthetic reasons (P = 0.012). CONCLUSIONS The 20-year prognosis of endodontically treated/re-treated teeth as part of multidisciplinary rehabilitation of patients affected by advanced periodontitis is good. Aging, two-stage endodontic treatment, and endodontic treatment for non-endodontic reasons are important predictors of failure
Assessing the impact of COVID-19 on liver cancer management (CERO-19)
Background & Aims: The coronavirus disease 2019 (COVID-19) pandemic has posed unprecedented challenges to healthcare
systems and it may have heavily impacted patients with liver cancer (LC). Herein, we evaluated whether the schedule of LC
screening or procedures has been interrupted or delayed because of the COVID-19 pandemic.
Methods: An international survey evaluated the impact of the COVID-19 pandemic on clinical practice and clinical trials from
March 2020 to June 2020, as the first phase of a multicentre, international, and observational project. The focus was on
patients with hepatocellular carcinoma or intrahepatic cholangiocarcinoma, cared for around the world during the first
COVID-19 pandemic wave.
Results: Ninety-one centres expressed interest to participate and 76 were included in the analysis, from Europe, South America,
North America, Asia, and Africa (73.7%,17.1%, 5.3%, 2.6%, and 1.3% per continent, respectively). Eighty-seven percent of the centres
modified their clinical practice: 40.8% the diagnostic procedures, 80.9% the screening programme, 50% cancelled curative and/or
palliative treatments for LC, and 41.7% modified the liver transplantation programme. Forty-five out of 69 (65.2%) centres in
which clinical trials were running modified their treatments in that setting, but 58.1% were able to recruit new patients. The
phone call service was modified in 51.4% of centres which had this service before the COVID-19 pandemic (n = 19/37).
Conclusions: The first wave of the COVID-19 pandemic had a tremendous impact on the routine care of patients with liver
cancer. Modifications in screening, diagnostic, and treatment algorithms may have significantly impaired the outcome of
patients. Ongoing data collection and future analyses will report the benefits and disadvantages of the strategies imple mented, aiding future decision-making
Upper airway and systemic inflammation in obstructive sleep apnoea
Obstructive sleep apnoea (OSA) is associated with pharyngeal inflammation, but the coexistence of systemic inflammation is controversial. This study investigated whether local and systemic inflammatory biomarkers are related in patients with OSA. An uncontrolled extension to the study assessed the response to effective treatment. We recruited 89 patients with OSA (apnoea/hypopnoea index (AHI) =5 events · h-1), 28 snorers and 26 healthy controls. Pharyngeal lavage (PHAL) and plasma samples were collected at baseline and after a 1-year follow-up. Inflammatory cells were evaluated by flow cytometry; interleukin (IL)-6, IL-8 and tumour necrosis factor-a were evaluated by immunoassay. In PHAL, CD4+ T-cells, IL-6 and IL-8 were higher in OSA patients than in snorers or healthy controls ( p<0.05). The AHI correlated with CD4+, IL-6 and IL-8 in PHAL (all p-values <0.05). There were no differences in the inflammatory biomarkers in plasma between the study groups and no relationship between plasma and PHAL biomarkers. Biomarkers decreased significantly in PHAL but not in plasma after 1 year of therapy with continuous positive airway pressure or surgery. In patients with OSA, increased levels of inflammatory biomarkers were found in PHAL, which were reduced with effective treatment. No simultaneous increase in plasma inflammatory biomarkers was found. Copyrigh
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Soluble RAGE in COPD, with or without coexisting obstructive sleep apnoea
Background: Hypoxia can reduce the levels of soluble receptor for advanced glycation end-products (sRAGE), a new anti-inflammatory biomarker of COPD. We assessed sRAGE in patients with hypoxia-related diseases such as COPD, OSA and OSA-COPD overlap. Methods: Plasma levels of sRAGE were measured in 317 subjects at baseline (57 heathy nonsmokers HNS], 84 healthy smokers HS], 79 OSA, 62 COPD and 35 OSA-COPD overlap patients) and in 294 subjects after one year of follow-up (50 HNS, 74 HS, 77 OSA, 60 COPD and 33 overlap). Results: After adjusting for age, sex, smoking status and body mass index, sRAGE levels showed a reduction in OSA (- 12.5%, p = 0.005), COPD (- 14.8%, p < 0.001) and OSA-COPD overlap (- 12.3%, p = 0.02) compared with HNS. There were no differences when comparing sRAGE plasma levels between overlap patients and those with OSA or COPD alone. At follow-up, sRAGE levels did not change significantly in healthy subjects, COPD and OSA or OSA-COPD overlap nontreated with continuous positive airway pressure (CPAP). Moreover, in patients with OSA and OSA-COPD overlap who were treated with CPAP, sRAGE increased significantly. Conclusions: The levels of sRAGE are reduced in COPD and OSA. Treatment with CPAP appears to improve sRAGE levels in patients with OSA who also had COPD
Efecto del bicarbonato sobre el crecimiento de los patrones de cítricos: mandarino Cleopatra, Poncirus trifoliata, Forner-Alcaide nº 030131 y Forner-Alcaide nº 030141
Se ha llevado a cabo un ensayo en el que se estudia el crecimiento (altura y
peso fresco y seco del brote nuevo) de mandarino Cleopatra, Poncirus trifoliata y
dos de sus híbridos Forner-Alcaide (FA) FA 030131 y FA 030141 ante diferentes
concentraciones de bicarbonato. Estos patrones se cultivaron durante 84 días, en
macetas de 3L con arena silícea, regadas con soluciones nutritivas tipo Hoagland (20
μM de hierro) con diferentes concentraciones de bicarbonato sódico (0, 10 y 20 mM).
El patrón menos afectado por la concentración creciente de bicarbonato ha sido el
mandarino Cleopatra. Por el contrario el P. trifoliata fue el patrón en el que más se
redujo el crecimiento, tanto en altura como en peso fresco y seco del brote nuevo. El
efecto del bicarbonato fue diferente según el híbrido, el FA 030141 disminuyó más su
crecimiento con altas dosis de bicarbonato (20 mM), aunque estadísticamente no fue
significativo, mientras que en el FA 030131 el efecto reductor fue similar con ambas
dosis de bicarbonato (10 y 20mM)
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