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Drag reduction induced by a polydisperse solution of polyethylene oxide is investigated by direct numerical simulations of the Navier–Stokes equations coupled with the Lagrangian evolution of the polymers, modelled as dumbbells. Simulation parameters are chosen to match the experimental conditions of Berman (1977), who measured the polymer molecular weight distribution. Drag reduction is induced only by the few high molecular weight polymers fully stretched by the turbulent flow, whilst the hundreds of parts per million of low molecular weight chains are ineffective.
Polymer chains in turbulent flows are generally modelled as dumbbells, i.e. two beads joined by a nonlinear spring. The dumbbell only maps a single spatial configuration, described by the polymer end-to-end vector, thus a multi-bead FENE (finitely extensible nonlinear elastic) chain seems a natural improvement for a more accurate characterisation of the polymer spatial conformation. At a large Weissenberg number, a comparison with the more accurate Kuhn chain reveals that the multi-bead FENE chain drastically overestimates the probability of folded configurations. Surprisingly, the dumbbell turns out to be the only meaningful bead-spring model to coarse-grain a polymer macromolecule in turbulent pipe flows.
Two-way momentum-coupled direct numerical simulations of a particle-laden turbulent channel flow are addressed to investigate the effect of the particle Stokes number and of the particle-to-fluid density ratio on the turbulence modification. The exact regularised point-particle method is used to model the interphase momentum exchange in presence of solid boundaries, allowing the exploration of an extensive region of the parameter space. Results show that the particles increase the friction drag in the parameter space region considered, namely the Stokes number $St_+ \in [2,80]$, and the particle-to-fluid density ratio $\rho _p/\rho _f \in [90,5760]$ at a fixed mass loading $\phi =0.4$. It is noteworthy that the highest drag occurs for small Stokes number particles. A measurable drag increase occurs for all particle-to-fluid density ratios, the effect being reduced significantly only at the highest value of $\rho _p/\rho _f$. The modified stress budget and turbulent kinetic energy equation provide the rationale behind the observed behaviour. The particles’ extra stress causes an additional momentum flux towards the wall that modifies the structure of the buffer and of the viscous sublayer where the streamwise and wall-normal velocity fluctuations are increased. Indeed, in the viscous sublayer, additional turbulent kinetic energy is produced by the particles’ back-reaction, resulting in a strong augmentation of the spatial energy flux towards the wall where the energy is ultimately dissipated. This behaviour explains the increase of friction drag in particle-laden wall-bounded flows.
Obstructive pathology is a benign condition of the salivary glands that can affect elderly and co-morbid people. Sialoendoscopy is a minimally invasive surgical procedure with a success rate comparable to standard sialoadenectomy and has the advantage that it can be performed under local anaesthesia.
Methods
This study aimed to assess sialoendoscopy benefits in elderly patients unfit for general anaesthesia. A group of elderly patients (aged 65 years or more) undergoing sialoendoscopy under local anaesthesia were evaluated. Age, co-morbidities, surgical time, hospital stay, and complication and recurrence rates were assessed.
Results
Nineteen sialoendoscopies were performed in 18 elderly patients with a mean age of 69.7 ± 5.6 years, with some of them suffering from multiple co-morbidities. Surgery was successful in 16 patients, while surgery was unsuccessful in 2 patients because of intraglandular stones. The average surgical duration was 54.5 ± 30.1 minutes, and all patients were discharged 2–3 hours after surgery. No post-operative complications were found and only one patient had recurrence during follow up.
Conclusion
Sialoendoscopy under local anaesthesia is a safe and effective procedure in elderly patients who are more prone to complications.
Pandemic are known to generate traumatic events, such as job losses or violence [1]. Several studies have shown that epidemics and related health measures (quarantine, confinement) lead to an increase of acute stress disorders (ASD), post-traumatic stress disorders (PTSD), anxiety and depression in the adult population [2]. In the pediatric population, few studies have been carried out on the psychiatric outcomes during and after epidemics and associated measures [3].
Objectives
The aim of this study was to explore ASD symptoms during stay-at-home and Covid 19 pandemic and its impact on children and adolescent mental health.
Methods
Sixty participants (53% girls and 47% boys; mean age= 9 years 5 months) were included in this longitudinal study [4]. The measures consist in an emergency semi-directed interview designed to assess symptoms of ASD according to the age of children.
Results
Patients’ age modulated psychiatric outcomes. Children under the age of six shown more developmental regressions and more restlessness than older ones. Children from 6 to 12 years were characterized by more oppositional behaviors than adolescents. Finally, adolescents were characterized by more social isolation than younger ones. Other symptoms appear to be more stable across ages: sleep disturbance, fear behavior and somatization.
Conclusions
Young children experienced more externalized symptoms (opposition and agitation) and developmental regressions than older children [5]. Thus, it appears necessary during pandemic to take into account the psychiatric consequences of confinement to reduce psychosocial long-term outcomes in particular in younger patients who appeared to develop specific and age-related psychiatric disorders.
Despite their proven efficacy and tolerability, many patients are often switched among antipsychotics therapies due to the lack of therapeutic response. Many physicians begin to switching antipsychotics with the original intention to discontinue the drug, and, continue with another therapy. Several new antipsychotics available allow us to improve the long- term therapy.
Methods
Nineteen year open label study in ‘real world’ setting in 121 inpatients with schizophrenia (DSM-III -> DSM-IV-TR) observed first time in 1992 in a neuropsychiatric centre and subsequently clinically evaluated until 2011; data collected and compared to switching between antipsychotics (from haloperidol to clozapine, risperidone, olanzapine, quetiapine, aripiprazole). At baseline: epidemiogical and biological parameters, PANSS, QLindex and, subsequently, with CGI-S scores during every clinical visit of control [T1 → T7]. The overall analysis carried out with EZAnalyze(c) ver.3.0.
Results
In the clozapine group remission rates were higher than other groups; Interrupted therapy: 27.62% of patients with risperidone, 34.85% with quetiapine. A consistent number of patients (8.04%), who have suspended the ‘first’ therapy with haloperidol, have assumed again the therapy with haloperidol toT7. Outcome was good in 28.4%,intermediate in 50,1% and poor in 21%. CGI-S T7 vs T0 (Severity of illness= p: 0,0066; Global improvement = p: 0,02844; Efficacy index =p: 0,00597)
Conclusion
Study suggested that most clinically stable outpatients with schizophrenia maintain remission states after being switched to atypical antipsychotics; a T7 (19 years) a consistent number of patients assumed again haloperidol with satisfactory rate of 51.18% then previous pharmacological treatments with a atypical antipsychotics.
Childhood-onset schizophrenia (COS) is a rare but severe psychiatric disorder with important individual, family and societal consequences. Its prevalence is approximately 2 per 10.000 in the general population and the incidence of COS increases with age.
Objectives
The main objective of our study was to evaluate the prevalence of COS in French medical-social institutions or psychiatric day hospitals for children and adolescents in the PACA region. The secondary objectives were:
(1) to estimate the prevalence of children with both COS and autism diagnosis,
(2) to characterize clinical and neurocognitive presentation of COS using the evaluation of intensity of positive and negative symptoms (PANSS, SANS), of thought disorganization (TLC), of cognitive functioning, and of attention and executive functions (verbal fluency, TMT A, TMT B).
Methods
Subjects were patients from medical-social and psychiatric care centers for children and adolescents in three PACA sub-regions in the south-east of France. The study included French speaking girls and boys between 7 and 18 years old, registered in a partner structure of the study, and presenting an IQ > 35 (WISC-IV). The study design was constituted by two phases: the first one was the categorical diagnostic phase using the psychosis section of the Kiddie-SADS Present and Lifetime Version. The second phase consisted of the dimensional COS diagnosis and neurocognitive exploration for the subjects fulfilling the DSM-IV diagnostic criteria for schizophrenia.
Results
The diagnosis of COS was not exceptional in this population. Most subjects diagnosed with COS also presented autism diagnosis and mental retardation.
Conventional treatment programs of anorexia nervosa are successful in the restoration of body weight; however, recidivism is common and the rate of relapse is high. For twenty years, The Child and Adolescent Psychiatric Department of the University of Nice used to offer a standard treatment based on psychotherapy for both in/out-patients suffering from anorexia nervosa.
Objective
Progressively, we have developed an innovative pattern of care based on the psychopathologic hypothesis of troubles in early integration of perceptive functions. This way of caring constitute a form of therapy to fight anorectic symptoms by the re-appropriation of feelings and the affective reminders linked to them.
Methods
We have created 4 therapeutic workshops. Three of them use sensorial stimuli: olfactory, tactile-kinesthetic and auditory. The fourth one is a discussion group. We propose all adolescents to try these workshops in addition to the normal care program.
Results
We note two principal effects of this innovative way of caring: the reduction of the number and the duration of hospitalizations and the improvement of therapeutic alliance.
Conclusion
The scientific assessment of the impact of this sensory way of caring on the BMI, on the therapeutic alliance and on the hedonic faculties over 2 years is being. And the results should objectify our clinical findings.The use of sensory pathways and their relationship to memory traces and emotions helps the lifting of denial, the sagging of cleavages and reduces pain following the necessary weight regain in the institutional treatment of adolescent anorexia nervosa.
Negative symptoms constitute an important diagnostic and therapeutic challenge (Galderisi & Maj 2008). Negative symptoms are thought to be part of schizophrenia, at least in some patients (Kirkpatrick 2014). Despite that there are few treatment trials focused on primary negative symptoms (Chue P, Lalon de JK 2014).
Objectives
Open-observational study to evaluate the efficacy of SGA on negative symptoms, in according to the recommendations of Consensus Development Conference Attendes(CDCA) .
Aims
To consider the impact of SGAs in the treatment of primary negative symptoms.
Methods
We evaluated in 12-month-study efficacy of SGA in 42 inpatients with schizophrenia(DSM-5). Inclusion criteria: persistent negative symptoms with adequate antipsychotic treatment, clinically stable, minimal psychotic symptoms, depression/anxiety, EPS. Patients were treated with SGAs (clozapine; risperidone; quetiapine, olanzapine) and evaluated at baseline and after 1, 3, 6, 12 mouths with: PANSS; BPRS; Brief Negative Symptoms Scale (BNSS); CDSS. Data were collected and evaluated by EZanalize /Excel.
Results
Data obtained with BNSS and PANSS scales show no significant differences in olanzapine and risperidone groups. Clozapine-treated patients had a significant reduction in BNSS score (p < .03) and particularly in asociality and avolition subscales. Although no significant difference was found in the PANSS and BNSS total scores in all groups; quetiapine group showed significant symptoms reduction in the PANSS and BNSS, alogia subscale (p <=.06).
Conclusion
There are not studies that show a superiority of a drug over another in negative symptoms therapy. However, emergine results show that some antipsychotics act preferentially on some specific items of group of symptoms.
The use of atypical antipsychotics (SGAs) is hindered by the frequent occurrence of metabolic side effects, resulting in worsened quality of life and greater mortality as a result of increased risk factors for metabolic syndrome [2] [3] in schizophrenic patients compared with general population [1].
Objectives:
To establish the relationship between antipsychotic efficacy and side effects, especially the impact of various antipsychotics on metabolic parameters after 20-year treatment with atypical (SGAs) and typical antipsychotics (FGAs)
Aims:
To identify advantages and disvantages of SGAs in terms of quality of life, costs and benefits.
Methods:
Forty-five psychiatric inpatients diagnosed with schizophrenia or schizoaffective disorder (DSM-IV-TR diagnosis), treated with typical (haloperidol) and atypical (clozapine, risperidone, olanzapine, quetiapine, aripiprazole) antipyschotics, were studied retrospectively during 20 years. We use data at baseline, follow-up: 1, 5, 10, 20 years. Rating scales administered: CGI-I, SAPS, SANS, PANSS.
Results:
The results have underlined a statistically significant variations(p value <.05) of the lipidic and glicidic profile. We have also found a reduction of the recorded values at endpoint vs baseline in aripiprazole and haloperidol groups. The glicemic values, were not statistically different in quetiapine, aripiprazole, risperidone and haloperidol groups. No significant statistical variations were observed in complete blood count, electrocardiogram, liver enzymes blood pressure and body weight.
Conclusions:
The results confirm studies on efficacy and effectiveness of both SGAs and FGAs, and their influence on metabolic profile and other biological parameters. These data can represent a’real world’ study in patients observed during our daily out-patient practice.
The exact regularised point particle (ERPP) method is extended to treat the inter-phase momentum coupling between particles and fluid in the presence of walls by accounting for vorticity generation due to particles close to solid boundaries. The ERPP method overcomes the limitations of other methods by allowing the simulation of an extensive parameter space (Stokes number, mass loading, particle-to-fluid density ratio and Reynolds number) and of particle spatial distributions that are uneven (few particles per computational cell). The enhanced ERPP method is explained in detail and validated by considering the global impulse balance. In conditions when particles are located close to the wall, a common scenario in wall-bounded turbulent flows, the main contribution to the total impulse arises from the particle-induced vorticity at the solid boundary. The method is applied to direct numerical simulations of particle-laden turbulent pipe flow in the two-way coupling regime to address turbulence modulation. The effects of the mass loading, the Stokes number and the particle-to-fluid density ratio are investigated. The drag is either unaltered or increased by the particles with respect to the uncoupled case. No drag reduction is found in the parameter space considered. The momentum stress budget, which includes an extra stress contribution by the particles, provides the rationale behind the drag behaviour. The extra stress produces a momentum flux towards the wall that strongly modifies the viscous stress, the culprit of drag at solid boundaries.
The generalised Kolmogorov equation is used to describe the scale-by-scale turbulence dynamics in the shear layer and in the separation bubble generated by a bulge at one of the walls in a turbulent channel flow. The second-order structure function, which is the basis of such an equation, is used as a proxy to define a scale-energy content, that is an interpretation of the energy associated with a given scale. Production and dissipation regions and the flux interchange between them, in both physical and separation space, are identified. Results show how the generalised Kolmogorov equation, a five-dimensional equation in our anisotropic and strongly inhomogeneous flow, can describe the turbulent flow behaviour and related energy mechanisms. Such complex statistical observables are linked to a visual inspection of instantaneous turbulent structures detected by means of the Q-criterion. Part of these turbulent structures are trapped in the recirculation where they undergo a pseudo-cyclic process of disruption and reformation. The rest are convected downstream, grow and tend to larger streamwise scales in an inverse cascade. The classical picture of homogeneous isotropic turbulence in which energy is fed at large scales and transferred to dissipate at small scales does not simply apply to this flow where the energy dynamics strongly depends on position, orientation and length scale.
Turbulent flow separation induced by a protuberance on one of the walls of an otherwise planar channel is investigated using direct numerical simulations. Different bulge geometries and Reynolds numbers – with the highest friction Reynolds number simulation reaching a peak of $Re_{\unicode[STIX]{x1D70F}}=900$ – are addressed to understand the effect of the wall curvature and of the Reynolds number on the dynamics of the recirculating bubble behind the bump. Global quantities reveal that most of the drag is due to the form contribution, whilst the friction contribution does not change appreciably with respect to an equivalent planar channel flow. The size and position of the separation bubble strongly depends on the bump shape and the Reynolds number. The most bluff geometry has a larger recirculation region, whilst the Reynolds number increase results in a smaller recirculation bubble and a shear layer more attached to the bump. The position of the reattachment point only depends on the Reynolds number, in agreement with experimental data available in the literature. Both the mean and the turbulent kinetic energy equations are addressed in such non-homogeneous conditions revealing a non-trivial behaviour of the energy fluxes. The energy introduced by the pressure drop follows two routes: part of it is transferred towards the walls to be dissipated and part feeds the turbulent production hence the velocity fluctuations in the separating shear layer. Spatial energy fluxes transfer the kinetic energy into the recirculation bubble and downstream near the wall where it is ultimately dissipated. Consistently, anisotropy concentrates at small scales near the walls irrespective of the value of the Reynolds number. In the bulk flow and in the recirculation bubble, isotropy is restored at small scales and the isotropy recovery rate is controlled by the Reynolds number. Anisotropy invariant maps are presented, showing the difficulty in developing suitable turbulence models to predict separated turbulent flow dynamics. Results shed light on the processes of production, transfer and dissipation of energy in this relatively complex turbulent flow where non-homogeneous effects overwhelm the classical picture of wall-bounded turbulent flows which typically exploits streamwise homogeneity.
Geometric uncertainties limit the accuracy of three-dimensional conformal radiotherapy treatments. This study aims to evaluate typical random and systematic set-up errors and analyse the impact of no action level (NAL) correction protocol on systematic set-up errors and clinical target volume (CTV)–planning target volume (PTV) margins.
Materials and methods
A total 668 pairs of orthogonal electronic portal images were compared with digitally reconstructed radiographs from computed tomography planning scans for 100 patients consecutively treated during 2011. Patients were divided into groups depending on the treated anatomical region. Patient-specific and population random and systematic set-up errors were calculated. Impact of application of NAL correction protocol on systematic set-up errors and CTV–PTV expansions were evaluated.
Results
Population set-up errors resulted from about 1 mm in head and neck to 2–3 mm in prostate, rectum, lung, breast and gynaecological districts. Patient-specific systematic set-up errors were higher for breast and gynaecological districts and application of NAL correction protocol gave significant reductions, even higher than 30%. Calculated CTV–PTV margins ranged from 10 mm on left–right direction for prostate to 20 mm on superior–inferior direction for lung.
Conclusions
Set-up errors resulted reasonably controlled and application of NAL correction protocol could further improve the level of accuracy. However, the NAL application alone did not seem to add any substantial benefit on CTV–PTV total margins without the adoption of corrective strategies to reduce other important uncertainties limiting accuracy of three-dimensional conformal radiotherapy.
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