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The purpose of this research is to provide a new understanding of the turbulence dynamics in a heated flow of fluid at supercritical pressure. A unified explanation has been established for the laminarisation mechanisms due to the variations of thermophysical properties, buoyancy and inertia, the last of which plays a significant role in a developing flow. In the new understanding, the various factors can all be treated similarly as (pseudo-)body forces, the effect of which is to cause a reduction in the so-called apparent Reynolds number. The partially laminarising flow is represented by an equivalent-pressure-gradient reference flow plus a perturbation flow. Full laminarisation is used in the paper referring to a region where no new vortical structures are generated. This region is akin to the pre-transition region of a boundary layer bypass transition, and in both cases, the free-stream or pipe-core turbulence decays exponentially, but elongated streaks are formed in the boundary layer. Turbulence kinetic energy in this region may still be significant due to the decaying turbulence as well as newly generated streaks. The latter lead to an increase in streamwise velocity fluctuations near the wall. Later, re-transition occurs when the streaks break down and multi-scale vortices are generated, leading to an increase in the radial and circumferential velocity fluctuations. The structural effect of buoyancy on turbulence is weak and negative in the partially laminarising flow, but is dominant in the full laminarisation and re-transition regions.
Gas-fluidized beds of flexible fibres, which have been rarely studied before, are investigated in this work using the coupled approach of the discrete element method and computational fluid dynamics. In the present numerical method, gas–fibre interaction is modelled by calculating the interaction force for each constituent element in the fibre, and the composition of the interaction forces on the constituent elements generates a resultant hydrodynamic force and a resultant hydrodynamic torque on the fibre. Pressure drops and fibre orientation results from the present simulations with various fibre aspect ratios are in good agreement with previous experimental and simulation results. Some novel results are obtained for the effects of fibre flexibility. Larger hydrodynamic forces on fibres (before the bed is fluidized) and smaller minimum fluidization velocities (MFVs) are observed for more flexible fibre beds due to the smaller porosities, while smaller hydrodynamic forces are obtained for the more flexible fibres when the beds are fluidized with significant fibre motion. By scaling the superficial gas velocity using the MFVs, the data of pressure drop can collapse onto the Ergun correlation for stiff fibres of various aspect ratios; however, the pressure drop curves deviate from the Ergun correlation for very flexible fibres, due to the significant fibre bed expansion before the MFV is reached. The fibre aspect ratio and flexibility both have an impact on the solids mixing rate, and it is found that the solids mixing rates are essentially determined by the ratio of the superficial gas velocity to MFV.
A study of low-speed streaks (LSSs) embedded in the near-wall region of a turbulent boundary layer is performed using selective visualization and analysis of time-resolved tomographic particle image velocimetry (tomo-PIV). First, a three-dimensional velocity field database is acquired using time-resolved tomo-PIV for an early turbulent boundary layer. Second, detailed time-line flow patterns are obtained from the low-order reconstructed database using ‘tomographic visualizations’ by Lagrangian tracking. These time-line patterns compare remarkably well with previously observed patterns using hydrogen bubble flow visualization, and allow local identification of LSSs within the database. Third, the flow behaviour in proximity to selected LSSs is examined at varying wall distances (
$10 < y^+ < 100$
) and assessed using time-line and material surface evolution, to reveal the flow structure and evolution of a streak, and the flow structure evolving from streak development. It is observed that three-dimensional wave behaviour of the detected LSSs appears to develop into associated near-wall vortex flow structures, in a process somewhat similar to transitional boundary layer behaviour. Fourth, the presence of Lagrangian coherent structures is assessed in proximity to the LSSs using a Lagrangian-averaged vorticity deviation process. It is observed that quasi-streamwise vortices, adjacent to the sides of the streak-associated three-dimensional wave, precipitate an interaction with the streak. Finally, a hypothesis based on the behaviour of soliton-like coherent structures is made which explains the process of LSS formation, bursting behaviour and the generation of hairpin vortices. Comparison with other models is also discussed.
The Eating Assessment in Toddlers FFQ (EAT FFQ) has been shown to have good reliability and comparative validity for ranking nutrient intakes in young children. With the addition of food items (n 4), we aimed to re-assess the validity of the EAT FFQ and estimate calibration factors in a sub-sample of children (n 97) participating in the Growing Up Milk – Lite (GUMLi) randomised control trial (2015–2017). Participants completed the ninety-nine-item GUMLi EAT FFQ and record-assisted 24-h recalls (24HR) on two occasions. Energy and nutrient intakes were assessed at months 9 and 12 post-randomisation and calibration factors calculated to determine predicted estimates from the GUMLi EAT FFQ. Validity was assessed using Pearson correlation coefficients, weighted kappa (κ) and exact quartile categorisation. Calibration was calculated using linear regression models on 24HR, adjusted for sex and treatment group. Nutrient intakes were significantly correlated between the GUMLi EAT FFQ and 24HR at both time points. Energy-adjusted, de-attenuated Pearson correlations ranged from 0·3 (fibre) to 0·8 (Fe) at 9 months and from 0·3 (Ca) to 0·7 (Fe) at 12 months. Weighted κ for the quartiles ranged from 0·2 (Zn) to 0·6 (Fe) at 9 months and from 0·1 (total fat) to 0·5 (Fe) at 12 months. Exact agreement ranged from 30 to 74 %. Calibration factors predicted up to 56 % of the variation in the 24HR at 9 months and 44 % at 12 months. The GUMLi EAT FFQ remained a useful tool for ranking nutrient intakes with similar estimated validity compared with other FFQ used in children under 2 years.
Coronavirus disease 2019 (COVID-19) is a global health threat. A hospital in Zhuhai adopted several measures in Fever Clinic Management (FCM) to respond to the outbreak of COVID-19. FCM has been proved to be effective in preventing nosocomial cross infection. Faced with the emergency, the hospital undertook creative operational steps in relation to the control and spread of COVID-19, with special focuses on physical and administrative layout of buildings, staff training and preventative procedures. The first operational step was to set up triaging stations at all entrances and then complete a standard and qualified fever clinic, which was isolated from the other buildings within our hospital complex. Secondly, the hospital established its human resource reservation for emergency response and the allocation of human resources to ensure strict and standardised training methods through the hospital for all medical staff and ancillary employees. Thirdly, the hospital divided the fever clinic into partitioned areas and adapted a three-level triaging system. The experiences shared in this paper would be of practical help for the facilities that are encountering or will encounter the challenges of COVID-19, i.e. to prevent nosocomial cross infection among patients and physicians.
Soybean meal is rich in soybean isoflavones, which exhibit antioxidant, anti-inflammatory, antiviral and anticancer functions in humans and animals. This study was conducted to investigate the effects of soybean isoflavones on the growth performance, intestinal morphology and antioxidative properties in pigs. A total of 72 weaned piglets (7.45 ± 0.13 kg; 36 males and 36 females) were allocated into three treatments and fed corn-soybean meal (C-SBM), corn-soy protein concentrate (C-SPC) or C-SPC supplemented with equal levels of the isoflavones found in the C-SBM diet (C-SPC + ISF) for a 72-day trial. Each treatment had six replicates and four piglets per replicate, half male and half female. On day 42, one male pig from each replicate was selected and euthanized to collect intestinal samples. The results showed that compared to pigs fed the C-SPC diet, pigs fed the C-SBM and C-SPC + ISF diets had higher BW on day 72 (P < 0.05); pigs fed the C-SBM diet had significantly higher average daily gain (ADG) during days 14 to 28 (P < 0.05), with C-SPC + ISF being intermediate; pigs fed the C-SBM diet tended to have higher ADG during days 42 to 72 (P = 0.063), while pigs fed the C-SPC + ISF diet had significantly higher ADG during days 42 to 72 (P < 0.05). Moreover, compared to pigs fed the C-SPC diet, pigs fed the C-SBM diet tended to have greater villus height (P = 0.092), while pigs fed the C-SPC + ISF diet had significantly greater villus height (P < 0.05); pigs fed the C-SBM and C-SPC + ISF diets had significantly increased villus height-to-crypt depth ratio (P < 0.05). Compared with the C-SPC diet, dietary C-SPC + ISF tended to increase plasma superoxide dismutase activity on days 28 (P = 0.085) and 42 (P = 0.075) and reduce plasma malondialdehyde (MDA) content on day 42 (P = 0.089), as well as significantly decreased jejunal mucosa MDA content on day 42 (P < 0.05). However, no significant difference in the expression of tight junction genes among the three groups was found (P > 0.05). In conclusion, our results suggest that a long-term exposure to soybean isoflavones enhances the growth performance, protects the intestinal morphology and improves the antioxidative properties in pigs.
At present, analysis of diet and bladder cancer (BC) is mostly based on the intake of individual foods. The examination of food combinations provides a scope to deal with the complexity and unpredictability of the diet and aims to overcome the limitations of the study of nutrients and foods in isolation. This article aims to demonstrate the usability of supervised data mining methods to extract the food groups related to BC. In order to derive key food groups associated with BC risk, we applied the data mining technique C5.0 with 10-fold cross-validation in the BLadder cancer Epidemiology and Nutritional Determinants study, including data from eighteen case–control and one nested case–cohort study, compromising 8320 BC cases out of 31 551 participants. Dietary data, on the eleven main food groups of the Eurocode 2 Core classification codebook, and relevant non-diet data (i.e. sex, age and smoking status) were available. Primarily, five key food groups were extracted; in order of importance, beverages (non-milk); grains and grain products; vegetables and vegetable products; fats, oils and their products; meats and meat products were associated with BC risk. Since these food groups are corresponded with previously proposed BC-related dietary factors, data mining seems to be a promising technique in the field of nutritional epidemiology and deserves further examination.
This pooled analysis compared the efficacy of venlafaxine extended-release (XR) versus placebo in the treatment of social anxiety disorder (SAD).
Data were pooled from 5 randomized studies of patients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) SAD (N=1459) who were treated with venlafaxine XR 75 mg/d to 225 mg/d or placebo for 12 weeks (4 studies) or 28 weeks (1 study). Response and remission rates were calculated for the overall sample, as well as stratified by gender and level of physical symptom severity at baseline. Response was defined as a score of 1 or 2 on the Clinical Global Impressions–Improvement (CGI-I) scale. Remission was defined as a total score of <30 on the Leibowitz Social Anxiety Scale (LSAS).
At baseline the mean LSAS score was 88.1 and 86.6 for the venlafaxine and placebo arms, respectively. Overall response rates at week 12 were 55% for venlafaxine XR and 33% for placebo (P<0.0001); remission rates were 25% and 12%, respectively (P<0.0001). Among patients with less severe physical symptoms, response rates were 52% and 32% for venlafaxine XR and placebo, respectively (P<0.0001); remission rates were 27% and 14%, respectively (P<0.0001). Response rates among patients with more severe physical symptoms were 56% for venlafaxine XR and 33% for placebo (P<0.0001); remission rates were 24% and 11%, respectively (P<0.0001).
Venlafaxine XR is effective in the treatment of SAD, regardless of gender or severity of physical symptoms.
To assess the efficacy of desvenlafaxine succinate (DVS) treatment in patients with major depressive disorder (MDD).
Seven randomized, double-blind, placebo-controlled, short-term studies were pooled to evaluate the efficacy of DVS in MDD. Adult outpatients with DSM-IV MDD were enrolled in all studies. Eligible patients were randomly assigned to DVS (n=1186) at doses of 100–400 mg/d, or placebo (n=797) for 8 weeks. The 17-item Hamilton Depression Rating Scale (HAM-D17) was the primary efficacy variable. Other efficacy variables were the Clinical Global Impressions scale (CGI), HAM-D6, Montgomery Åsberg Depression Rating Scale (MADRS), Covi Anxiety scale, Sheehan Disability Scale (SDS), WHO-5 Well-Being Index, and the Visual Analog Scale–Pain Intensity (VAS-PI). A mixed-effect model for repeated measures (MMRM) analysis was used to analyze continuous variables. Logistic regression was used to analyze response and remission rates.
An adjusted mean difference of –2.8 points on HAM-D17 total score at end point for DVS vs placebo (95% confidence limits: –2.2, –3.4; P<0.001) was demonstrated. Response and remission rates were significantly elevated for DVS-treated patients compared with placebo (P<0.001) across rating scales (HAM-D17, MADRS, and CGI). For other secondary measures at end point, including the CGI, HAM-D6, MADRS, Covi, SDS, WHO-5, and VAS-PI, significant differences from placebo were also observed. No additional benefit was observed for DVS doses above 100 mg/d in analyses of fixed-dose studies.
DVS was efficacious in treating MDD based on standard depression rating scales and measures of anxiety, global severity/improvement, functioning, well being, and pain.
In this meta-analysis we compared the effects of venlafaxine and SSRIs on work activity in MDD patients classified according to baseline severity
Data from the work and activity item 7 of the HAMD17 of 31 pooled studies comparing venlafaxine with SSRIs were used. Subjects were divided into two groups based on their baseline HAMD17 total score ≥30/< 30.Score distributions and the proportions of patients achieving full work functionality were summarized for both LOCF and Completers at week 8. Fisher's exact test was used to compare the treatment effects..
5836 patients with a baseline HAMD17 <30 were identified. The OR for all subjects achieving full work functionality is 1.22 (95%CI 1.08, 1.36), p<0.001 for LOCF and 1.19 (95%CI 1.04, 1.38), p=0.015 for completers. The OR for subjects with work impairment at baseline is 1.17 (95%CI 1.02, 1.35), p=0.029 for LOCF and 1.13 (95%CI 0.95, 1.35), p=0.18 for completers. 656 patients with a baseline HAMD17 >30 were identified. The OR for all subjects achieving full work functionality is 1.80 (95%CI 1.24, 2.63), p=0.002 for LOCF and 1.64 (95%CI 1.05, 2.58), p=0.032 for completers. The OR for subjects with work impairment at baseline is 1.93 (95%CI 1.30, 2.87), p=0.001 for LOCF and 1.81 (95%CI 1.12, 2.92), p=0.017 for completers.
This analysis demonstrates that venlafaxine is superior to SSRIs in improving work functionality in both mild/moderate and even more pronounced in severe depression. These results emphasize the impact of the treatment with venlafaxine on patients returning to normal social life.
Finding the prediction factors for the risks of post-stroke depression (PSD) is important to stroke survivors. However, most existing studies focused only on general clinical data, which limited the predictive ability. To improve the predictive ability, this study proposed a comprehensive PSD risk prediction model with social psychological factors, neurological, cognitive functional factors and general clinical factors.
The study recruited 188 stroke patients. Patients were diagnosed by DSM-IV criteria. Predictors were collected within a week after stroke. Boosted regression trees (BRT) was used to classify these predictors, and then a predictive model was constructed based on the selected predictors. The receiver operating characteristic (ROC) curve was used to determine the performance of the predictive model .
The risk prediction model was constructed with 6 factors: Body Mass Index (BMI), cerebral infraction history (CI), Social Support Rating Scale (SSRS), Eysenck Personality Questionnaire-Neuroticism (EPQ-N), factor 1 of the 20 items Toronto Alexithymia Scale (TAS-F1) and Snaith-Hamilton-Pleasure Scale (SHARPS). In the contribution of risk prediction factors, social psychological factors was more than 0.60. ROC curve of prediction model was 0.826 (p<0.001; 95% CI) and the accuracy of prediction was 0.81 (p<0.001). Transforming the prediction model to a tree diagram, it was convenient to clinic operation.
A PSD risk prediction model with good prediction performance was constructed to achieve diagnose concisely and clearly. The social psychological factors play an important role for diagnosing PSD in the early period.
The diagnosis of major depressive disorder (MDD) is symptom based due to the lack of biological biomarker. p11 protein was recently found to be an important factor mediating depression-like states and antidepressant responses. The aim of the study was to assess whether p11 protein in urine can serve as a potential biomarker for major depression, and the relationship of its levels among urine, serum and cerebrospinal fluid (CSF).
We obtained urine samples from 13 drug-free MDD patients and 13 age- and gender-matched healthy controls. We also collected urine, serum and cerebrospinal fluid samples from 13 of fracture patients or cesarean section patients in the spinal anesthesia. The concentrations of p11 protein were measured using ELISA.
In MDD patients, urine levels of p11 protein were all less than the minimum detectable concentration of the ELISA kit. The urine levels of p11 were detectable only in one healthy control. In the spinal anesthesia patients, we can detect p11 concentrations in both serum and urine in only two patients. Besides, levels of p11 were detectable in the serum of one patient and urine of another patient. We were unable to measure CSF levels of p11 in all patients.
Concentrations of p11 protein in the body fluids are very low and unstable. The sensitivity of the current p11 ELISA kit is currently unsatisfactory, requiring the development of an ELISA kit of higher sensitivity to determine whether p11 in body fluids can serve as biomarker for depression.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
The beginning of laminar–turbulent transition is usually associated with a wave-like disturbance, but its evolution and role in precipitating the development of other flow structures are not well understood from a structure-based view. Nonlinear parabolized stability equations (NPSE) were solved numerically to simulate the transition of K-regime, N-regime and O-regime. However, only the K-regime transition was examined experimentally using both hydrogen bubble visualization and time-resolved tomographic particle image velocimetry (tomo-PIV). Based on the ‘NPSE visualization’ and ‘tomographic visualization’, at least four common characteristics of the generic transition process were identified: (i) inflectional regions representing high-shear layers (HSL) that develop in vertical velocity profiles, accompanied by ejection–sweep behaviours; (ii) low-speed streak (LSS) patterns, manifested in horizontal timelines, that seem to consist of several three-dimensional (3-D) waves; (iii) a warped wave front (WWF) pattern, displaying multiple folding processes, which develops adjacent to the LSS in the near-wall region, prior to the appearance of 𝛬-vortices; (iv) a coherent 3-D wave front, similar to a soliton, in the upper boundary layer, accompanied by regions of depression along the flanks of the wave. It was determined that the amplification and lift-up of a 3-D wave causes the development of the HSL, WWF and multiple folding behaviour of material surfaces, that all contribute to the development of a 𝛬-vortex. The amplified 3-D wave is hypothesized as a soliton-like coherent structure. Based on our results, a path to transition is proposed, which hypothesizes the function of the WWF in boundary-layer transition.
Intelligent control of friction and adhesion has attracted much attention for use in soft robotics, human-sensor interfaces, and bionics. Here we introduce a shape memory photonic crystal (SMPC) polymer that can be programmed and recovered by solvent to realize switchable surface friction. Micro sliding test show that the friction coefficient on this SMPC in the programmed and recovered state can vary by three times. We also show that the mechanism behind this switchable friction coefficient is the surface roughness related adhesion.
Only 30% or fewer of individuals at clinical high risk (CHR) convert to full psychosis within 2 years. Efforts are thus underway to refine risk identification strategies to increase their predictive power. Our objective was to develop and validate the predictive accuracy and individualized risk components of a mobile app-based psychosis risk calculator (RC) in a CHR sample from the SHARP (ShangHai At Risk for Psychosis) program.
In total, 400 CHR individuals were identified by the Chinese version of the Structured Interview for Prodromal Syndromes. In the first phase of 300 CHR individuals, 196 subjects (65.3%) who completed neurocognitive assessments and had at least a 2-year follow-up assessment were included in the construction of an RC for psychosis. In the second phase of the SHARP sample of 100 subjects, 93 with data integrity were included to validate the performance of the SHARP-RC.
The SHARP-RC showed good discrimination of subsequent transition to psychosis with an AUC of 0.78 (p < 0.001). The individualized risk generated by the SHARP-RC provided a solid estimation of conversion in the independent validation sample, with an AUC of 0.80 (p = 0.003). A risk estimate of 20% or higher had excellent sensitivity (84%) and moderate specificity (63%) for the prediction of psychosis. The relative contribution of individual risk components can be simultaneously generated. The mobile app-based SHARP-RC was developed as a convenient tool for individualized psychosis risk appraisal.
The SHARP-RC provides a practical tool not only for assessing the probability that an individual at CHR will develop full psychosis, but also personal risk components that might be targeted in early intervention.
The Chinese National Twin Registry (CNTR), initiated in 2001, has now become the largest twin registry in Asia. From 2015 to 2018, the CNTR continued to receive Chinese government funding and had recruited 61,566 twin-pairs by 2019 to study twins discordant for specific exposures such as environmental factors, and twins discordant for disease outcomes or measures of morbidity. Omic data, including genetics, genomics, metabolomics, and proteomics, and gut microbiome will be tested. The integration of omics and digital technologies in public health will advance our understanding of precision public health. This review introduces the updates of the CNTR, including study design, sample size, biobank, zygosity assessment, advances in research and future systems epidemiologic research.
The co-occurrence of hepatic cystic echinococcosis (CE) and alveolar echinococcosis (AE) is extremely rare. Here, we present the clinical manifestations and treatment outcomes of three cases with co-occurring CE and AE in the liver. Computed tomography (CT), magnetic resonance imaging and 18FFluorodeoxyglucose Positron Emission Tomography-CT were used for preoperative diagnosis. Specimens were taken intraoperatively and sent for pathological studies to confirm the coexistence of CE and AE by laminated membrane, daughter cysts or germinal layer and infiltration structure. Albendazole was prescribed after operation for 12 months. All patients were completely recovered and showed no recurrence at last follow-up. Therefore, surgical intervention and postoperative application of albendazole are recommended for patients with concurrence of hepatic AE and CE.
The Beijing Twin Study (BeTwiSt), which was established in 2006, is an ongoing study aiming to investigate the genetic and environmental etiology of adolescent psychopathology. Resting-state brain imaging datasets have been examined for same-sex twins, and other psychological traits and emotional and behavioral variables have been examined for all twins. Based on the registry, the main findings regarding the etiological mechanism underlying adolescent development, magnetic resonance imaging results, and genetic and environmental influences on other psychological traits have been published. This article summarizes the key findings in these three areas and discusses future plans for the BeTwiSt.