Bubble column reactors are multiphase contactors based on the dispersion of a gas phase in the form of bubbles inside a cylindrical vessel where a liquid or a suspension circulates. Those reactors ...present many advantages such as good heat and mass transfer rates, no moving parts, compactness, easy operating and low maintenance and operating costs. Their main drawback is the significant backmixing which can affect selectivity and conversion of reaction products. They have gained particular attention in the field of wastewater treatment for Wet Air Oxidation (WAO) processes application. Those processes are operated at high pressures (up to 30MPa) and temperatures (up to 573K). In order to efficiently operate those processes, conversion, heat and mass transfer must be optimised. Those parameters depend themselves on operating conditions such as pressure, temperature, superficial gas and liquid velocities and on design parameters such as sparger and column design. This review is aimed to find the relevant parameters for operating bubble column at high pressures and temperatures in continuous mode. The main mechanisms governing the bubble column will be described. The influence of the different parameters on gas holdup, mass transfer properties and on liquid axial dispersion coefficient will be extensively studied.
We present imaging data and photometry for the COSMOS survey in 15 photometric bands between 0.3 and 2.4 mu m. These include data taken on the Subaru 8.3 m telescope, the KPNO and CTIO 4 m ...telescopes, and the CFHT 3.6 m telescope. Special techniques are used to ensure that the relative photometric calibration is better than 1% across the field of view. The absolute photometric accuracy from standard-star measurements is found to be 6%. The absolute calibration is corrected using galaxy spectra, providing colors accurate to 2% or better. Stellar and galaxy colors and counts agree well with the expected values. Finally, as the first step in the scientific analysis of these data we construct panchromatic number counts which confirm that both the geometry of the universe and the galaxy population are evolving.
The massive inflow of patients with COVID-19 requiring urgent care has overloaded hospitals in France and impacts the management of other patients. Deferring hospitalization and non-urgent surgeries ...has become a priority for surgeons today in order to relieve the health care system. It is obviously not simple to reduce emergency surgery without altering the quality of care or leading to a loss of chance for the patient. Acute appendicitis is a very specific situation and the prevalence of this disease leads us to reconsider this particular disease in the context of the COVID-19 crisis. Indeed, while the currently recommended treatment for uncomplicated acute appendicitis is surgical appendectomy, the non-surgical alternative of medical management by antibiotic therapy alone has been widely evaluated by high-quality studies in the literature. Insofar as the main limitation of exclusively medical treatment of uncomplicated acute appendicitis is the risk of recurrent appendicitis, this treatment option represents an alternative of choice to reduce the intra-hospital overload in this context of health crisis. The aim of this work is therefore to provide physicians and surgeons with a practical guide based on a review of the literature on the medical treatment of uncomplicated acute appendicitis in adults, to offer this alternative treatment to the right patients and under good conditions, especially when access to the operating room is limited or impossible.
Background
Tumour extension beyond the mesorectal plane (ymrT4) occurs in 5–10 per cent of patients with rectal cancer and 10 per cent of patients develop locally recurrent rectal cancer (LRRC) after ...primary surgery. There is global variation in healthcare delivery for these conditions.
Methods
An international benchmark trial of the management of ymrT4 tumours and LRRC was undertaken in France and Australia between 2015 and 2017. Heterogeneity in management and operative decision‐making were analysed by comparison of surgical resection rates, blinded intercountry reading of pelvic MRI, quality‐of‐life assessment and qualitative evaluations.
Results
Among 154 patients (97 in France and 57 in Australia), 31·8 per cent had ymrT4 disease and 68·2 per cent LRRC. The surgical resection rates were 88 and 79 per cent in France and Australia respectively (P = 0·112). The concordance in operative planning was low (κ = 0·314); the rate of pelvic exenteration was lower in France than Australia both in clinical practice (36 of 78 versus 34 of 40; P < 0·001) and in theoretical conditions (10 of 25 versus 50 of 57; P = 0·002). The R0 resection rate was lower in France than Australia for LRRC (25 of 49 versus 18 of 21; P = 0·007) but not for ymrT4 tumours (21 of 26 versus 15 of 15; P = 0·139). Morbidity rates were similar. Patients who underwent non‐exenterative procedures had higher scores on the mental functioning subscale at 12 months (P = 0·047), and a lower level of distress at 6 months (P = 0·049). Qualitative analysis highlighted five categories of psychosocial factors influencing treatment decisions: patient, strategy, specialist, organization and culture.
Conclusion
This international benchmark trial has highlighted the differences in worldwide treatment of locally advanced and LRRC. Standardized care should improve outcomes for these patients.
Antecedentes
La extensión del tumor más allá del plano del meso‐rrecto (ymrT4) ocurre en el 5‐10% de los pacientes con cáncer de recto y el 10% de los pacientes desarrollan recidiva local del cáncer de recto (locally recurrent rectal cáncer, LRRC) después de una cirugía primaria. Existe una variación global en la prestación de la asistencia sanitaria para esta pato‐logía.
Métodos
Se realizó un ensayo de referencia internacional sobre el manejo de ymrT4 y LRRC en Francia y Australia entre 2015 y 2017. La heterogeneidad en el manejo y la toma de decisiones quirúrgicas se analizaron mediante la comparación de las tasas de resección quirúrgica, la lectura a ciegas de la resonancia magnética (RM) pélvica entre países, la evaluación de la calidad de vida y las evaluaciones cualitativas.
Resultados
De 154 pacientes (97 en Francia versus 57 en Australia), el 32% tenía ymrT4 y el 68% tenía cáncer de recto con recidiva local. Las tasas de resección quirúrgica fueron del 87,6% versus 77,8% (P = 0,112). La tasa de concordancia en la decisión quirúrgica fue baja (coeficiente kappa = 0,314) con una tasa más baja de exenteración pélvica en Francia, tanto en la práctica clínica (46% versus 85%; P < 0,0001) como en condiciones teóricas (40% versus 88%; P = 0,002). La tasa de resección R0 fue menor en Francia para la LRRC (51% versus 86%, P = 0,007) pero no para el ymrT4 (81% versus 100%, P = 0,139). Las tasas de morbilidad fueron similares. Los pacientes que se sometieron a procedimientos no exenterativos tuvieron una subescala de funcionamiento mental más alta a los 12 meses (P = 0,04) y un nivel de angustia más bajo a los 6 meses (P = 0,04). El análisis cualitativo destacó 5 categorías de factores psicosociales que afectaron a la decisión del tratamiento: paciente, estrategia, especialista, organización y cultura.
Conclusión
Este ensayo de referencia internacional destaca las diferencias en el tratamiento mundial del cáncer de recto localmente avanzado y de la LRR. La aten‐ción estandarizada debería mejorar los resultados para estos pacientes.
An international benchmark trial of the management of ymrT4 and locally recurrent rectal cancer was undertaken in France and Australia between 2015 and 2017. This trial highlights the differences in worldwide treatment of locally advanced and locally recurrent rectal cancer. Standardized care should improve outcomes for these patients.
Differences worldwide
G proteins play a central role in signal transduction and pharmacology. Signaling is initiated by cell-surface receptors, which promote guanosine triphosphate (GTP) binding and dissociation of Gα ...from the Gβγ subunits. Structural studies have revealed the molecular basis of subunit association with receptors, RGS proteins, and downstream effectors. In contrast, the mechanism of subunit dissociation is poorly understood. We use cell signaling assays, molecular dynamics (MD) simulations, and biochemistry and structural analyses to identify a conserved network of amino acids that dictates subunit release. In the presence of the terminal phosphate of GTP, a glycine forms a polar network with an arginine and glutamate, putting torsional strain on the subunit binding interface. This “G-R-E motif” secures GTP and, through an allosteric link, discharges the Gβγ dimer. Replacement of network residues prevents subunit dissociation regardless of agonist or GTP binding. These findings reveal the molecular basis of the final committed step of G protein activation.
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•Receptors promote GTP-GDP exchange and dissociation of G protein α and βγ subunits•An allosteric Gly-Arg-Glu (G-R-E) network links the γ phosphate of GTP to release of Gβγ•Gly-Arg-Glu mutations prevent subunit dissociation regardless of agonist or GTP binding•Gly-Arg-Glu mutations are responsible for human endocrine and neurological disorders
G protein signaling involves binding of agonist to receptor and unbinding of GDP from the G protein. Using integrated molecular and computational approaches, Knight et al. investigate the second, committed step of G protein activation, involving an allosteric “Gly-Arg-Glu” network that links GTP binding to subunit dissociation and pathway activation.
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