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In this paper, CuCr–Zr alloys prepared by vacuum melting with adding La and Ni elementswere heat-treated and aged, followed by plastic deformation using low-energy cyclic impact tests, to simultaneously improve their mechanical and electrical properties. Results showed that the grain size of the casted Cu–Cr–Zr alloys was significantly reduced after the solid-solution aging and plastic deformation process. There were a lot of dispersed Cr and Cu5Zr precipitates formed in the alloys, and the numbers of dislocations were significantly increased. Accordingly, the hardness was increased from 78 to 232 HV, and the tensile strength was increased from 225 to 691 MPa. Electrical conductivity has not been significantly affected after these processes. The enhancement of overall performance is mainly attributed to the combined effects of solid-solution hardening, fine grain hardening, and precipitation/dislocation strengthening.
Flavonoid-rich foods have shown a beneficial effect against non-alcoholic fatty liver disease (NAFLD) in short-term randomized trials and animal experiments. It is uncertain whether the usual dietary intake of flavonoids may benefit patients with NAFLD. This study evaluated the association between the usual intake of total flavonoids and their subclasses and the risk of progression in NAFLD. The prospective study included 2694 adults from the Guangzhou Nutrition & Health Study. Face-to-face interviews using a 79-item food frequency questionnaire were administered to assess habitual dietary flavonoid intake, while abdominal ultrasonography was conducted to evaluate the presence and degree of NAFLD, with measurements conducted three years apart. After adjustment for potential confounders, higher flavonoid intakes were gradely associated with reduced risks of worsen NAFLD status. The relative risks (95% CI) of worsening (vs. non-worsening) NAFLD in the highest (vs. lowest) quintile were 0.71 (0.54, 0.93) for total flavonoids, 0.74 (0.57, 0.95) for flavanones, 0.74 (0.56, 0.96) for flavan-3-ols, 0.90 (0.68, 1.18) for flavonols, 0.73 (0.56, 0.93) for flavones, 0.79 (0.61, 1.02) for isoflavones and 0.74 (0.57, 0.96) for anthocyanins. Sub-group analysis found that the beneficial associations were evident only in overweight/obese participants (P-interactions=0.015). An L-shaped (non-linear) relationship was observed between total flavonoid intake and the risk of NAFLD progression. Path analyses showed that the association between flavonoids and NAFLD progression was mediated by decreases in serum cholesterol and HOMA-IR. This prospective study showed that higher flavonoids intake was associated with a lower risk of NAFLD progression in the elderly overweight/obese Chinese population.
A one-dimensional steady-state model for stimulated Raman backscatter (SRS) and stimulated Brillouin backscatter (SBS) processes in laser-irradiated plasmas is presented. Based on a novel “predictor-corrector” method, the model is capable to deal with broadband scattered light and inhomogeneous plasmas, exhibiting robustness and high efficiency. Influences of the electron density and temperature on the linear gains of both SRS and SBS are investigated, which indicates that the SRS gain is more sensitive to the electron density and temperature than that of the SBS. For the low-density case, the SBS dominates the scattering process, while the SRS exhibits much higher reflectivity in the high-density case. The nonlinear saturation mechanisms and competition between SRS and SBS are included in our model by a phenomenological method. The typical anti-correlation between SRS and SBS versus electron density is reproduced in the model. Calculations of the reflectivities are qualitatively in agreement with the typical results of experiments and simulations.
Despite high altitude was implicated in adverse birth outcomes, there remained a paucity of evidence on low-to-medium altitude effect. This study aimed to explore the association of low-to-medium altitude with birth outcomes. A population-based cross-sectional survey was performed using a stratified multistage random sampling method among women with their infants born during 2010–2013 in Northwestern China. Altitude was determined in meters based on the village or community of the mother’s living areas. Birth outcomes involved birth weight, gestational age, and small for gestational age (SGA). Generalized linear models were fitted to investigate the association of altitude with birth outcomes. Moreover, the dose–response relationship between altitude and birth outcomes was evaluated with a restricted cubic spline function. A total of 27 801 women with their infants were included. After adjusting for potential confounders, every 100-m increase in the altitude was associated with reduced birth weight by 6.4 (95% CI −8.1, −4.6) g, the slight increase of gestational age by 0.015 (95% CI 0.010, 0.020) week, and an increased risk of SGA birth (odds ratio 1.03, 95% CI 1.02, 1.04). Moreover, there was an inversely linear relationship between altitude and birth weight (P for overall < 0.001 and P for nonlinear = 0.312), and a positive linear relationship between altitude and SGA (P for overall < 0.001 and P for nonlinear = 0.194). However, a nonlinear relationship was observed between altitude and gestational age (P for overall < 0.001 and P for nonlinear = 0.010). The present results suggest that low-to-medium altitude is possibly associated with adverse birth outcomes.
Phytase has long been used to decrease the inorganic phosphorus (Pi) input in poultry diet. The current study was conducted to investigate the effects of Pi supplementation on laying performance, egg quality and phosphate–calcium metabolism in Hy-Line Brown laying hens fed phytase. Layers (n = 504, 29 weeks old) were randomly assigned to seven treatments with six replicates of 12 birds. The corn–soybean meal-based diet contained 0.12% non-phytate phosphorus (nPP), 3.8% calcium, 2415 IU/kg vitamin D3 and 2000 FTU/kg phytase. Inorganic phosphorus (in the form of mono-dicalcium phosphate) was added into the basal diet to construct seven experimental diets; the final dietary nPP levels were 0.12%, 0.17%, 0.22%, 0.27%, 0.32%, 0.37% and 0.42%. The feeding trial lasted 12 weeks (hens from 29 to 40 weeks of age). Laying performance (housed laying rate, egg weight, egg mass, daily feed intake and feed conversion ratio) was weekly calculated. Egg quality (egg shape index, shell strength, shell thickness, albumen height, yolk colour and Haugh units), serum parameters (calcium, phosphorus, parathyroid hormone, calcitonin and 1,25-dihydroxyvitamin D), tibia quality (breaking strength, and calcium, phosphorus and ash contents), intestinal gene expression (type IIb sodium-dependent phosphate cotransporter, NaPi-IIb) and phosphorus excretion were determined at the end of the trial. No differences were observed on laying performance, egg quality, serum parameters and tibia quality. Hens fed 0.17% nPP had increased (P < 0.01) duodenum NaPi-IIb expression compared to all other treatments. Phosphorus excretion linearly increased with an increase in dietary nPP (phosphorus excretion = 1.7916 × nPP + 0.2157; R2 = 0.9609, P = 0.001). In conclusion, corn–soybean meal-based diets containing 0.12% nPP, 3.8% calcium, 2415 IU/kg vitamin D3 and 2000 FTU/kg phytase would meet the requirements for egg production in Hy-Line Brown laying hens (29 to 40 weeks of age).
The microstructure evolution, dynamic recrystallization (DRX) and precipitation of the ZM61 alloy sheets prepared with different rolling conditions were studied. The DRX grain sizes (dDRX) at four high strain rate rolling (HSRR) temperatures (275–350 °C) are 1.9, 2.3, 2.6 and 3.1 μm, respectively, while the DRX volume fractions (fVDRX) are 69, 73, 76 and 82%, respectively. 300 °C is selected as the optimal HSRR temperature. The dDRX and fVDRX of the alloys prepared by pre-rolling (PR) at 300 °C + HSRR are 1.0 μm and 91%, respectively. The PR treatment does not change the types of the precipitates but promotes the precipitation. The tensile strength (UTS) of 369 MPa and yield strength (YS) of 261 MPa can be achieved by HSRR at 300 °C, while a further increase in both UTS and YS can be obtained by PR treatment.
The role of severe respiratory coronavirus virus 2 (SARS-CoV-2)–laden aerosols in the transmission of coronavirus disease 2019 (COVID-19) remains uncertain. Discordant findings of SARS-CoV-2 RNA in air samples were noted in early reports.
Sampling of air close to 6 asymptomatic and symptomatic COVID-19 patients with and without surgical masks was performed with sampling devices using sterile gelatin filters. Frequently touched environmental surfaces near 21 patients were swabbed before daily environmental disinfection. The correlation between the viral loads of patients’ clinical samples and environmental samples was analyzed.
All air samples were negative for SARS-CoV-2 RNA in the 6 patients singly isolated inside airborne infection isolation rooms (AIIRs) with 12 air changes per hour. Of 377 environmental samples near 21 patients, 19 (5.0%) were positive by reverse-transcription polymerase chain reaction (RT-PCR) assay, with a median viral load of 9.2 × 102 copies/mL (range, 1.1 × 102 to 9.4 × 104 copies/mL). The contamination rate was highest on patients’ mobile phones (6 of 77, 7.8%), followed by bed rails (4 of 74, 5.4%) and toilet door handles (4 of 76, 5.3%). We detected a significant correlation between viral load ranges in clinical samples and positivity rate of environmental samples (P < .001).
SARS-CoV-2 RNA was not detectable by air samplers, which suggests that the airborne route is not the predominant mode of transmission of SARS-CoV-2. Wearing a surgical mask, appropriate hand hygiene, and thorough environmental disinfection are sufficient infection control measures for COVID-19 patients isolated singly in AIIRs. However, this conclusion may not apply during aerosol-generating procedures or in cohort wards with large numbers of COVID-19 patients.
Major depressive disorder is characterized by a high risk of relapse. We aimed to compare the prophylactic effects of different antidepressant medicines (ADMs).
PubMed, Cochrane Central Register of Controlled Trials, Embase and the Web of Science were searched on 4 July 2019. A pooled analysis of parametric survival curves was performed using a Bayesian framework. The main outcomes were hazard ratios (HRs), relapse-free survival and mean relapse-free months.
Forty randomized controlled trials were included. The 1-year relapse-free survival for ADM (76%) was significantly better than that for placebo (56%). Most of the relapse difference (86.5%) occurred in the first 6 months. Most HRs were not constant over time. Proof of benefit after 6 months of follow-up was not established partially because of small differences between the drug and placebo after 6 months. Almost all studies used an ‘enriched’ randomized discontinuation design, which may explain the high relapse rates in the first 6 months after randomization.
The superiority of ADM v. placebo was mainly attributed to the difference in relapse rates that occurred in the first 6 months. Our analysis provided evidence that the prophylactic efficacy was not constant over time. A beneficial effect was observed, but the prevention of new episodes after 6 months was questionable. These findings may have implications for clinical practice.
The objective of this paper is to explore the learning challenges of a group of first-year Papuan medical students. Perspectives were obtained from a group of Papuan medical students (attaining high and low grades) and Faculty staff (Papuan and Non-Papuan) at the University of Cenderawasih, Indonesia. This qualitative case study research employed semi-structured interviews conducted online via Skype. Data were analysed using a general inductive method and classified into themes to reflect Papuan students' learning challenges. We identified three main themes, namely the individual, the university and the outside environment. We found that these Papuan students were affected by their individual challenges, such as self-perception and the level of their learning and social skills. At the university level, students faced difficulties in adjusting their learning and felt that they were lacking a quiet supportive learning environment. They were also influenced by outside environment factors, such as family and financial concern. Given the wide range of challenges faced by Papuan medical students, Faculty development initiatives incorporating cultural responsiveness into the curriculum and wider government support are crucial for the successful educational advancement of Papuan medical students, which ultimately leads to better health outcomes for the Indigenous people of Papua.
The surface topology of biomaterial has a definite effect on the growth behavior of nerve cells for peripheral nerve regeneration. In this study, the silk fibroin (SF) film with different anisotropic microgroove/ridge was constructed by micropatterning technology. The effects of topologies width on the directional growth of dorsal root ganglion (DRG) neurons were evaluated. The results showed that the topological structure of the SF film with higher SF concentration was more clear and complete. The microtopography of the SF film with a concentration of 15% and a groove width of around 30 μm could effectively guide the directional growth of the nerve fibers of DRG. And nerve fibers could obviously form nerve fiber bundles which may have a certain pavement effect on the recovery of nerve function. The study indicated that the SF film with a specific width of the topological structure may have potential applications in the field of directional nerve regeneration.
The relationship between the subtypes of psychotic experiences (PEs) and common mental health symptoms remains unclear. The current study aims to establish the 12-month prevalence of PEs in a representative sample of community-dwelling Chinese population in Hong Kong and explore the relationship of types of PEs and common mental health symptoms.
This is a population-based two-phase household survey of Chinese population in Hong Kong aged 16–75 (N = 5719) conducted between 2010 and 2013 and a 2-year follow-up study of PEs positive subjects (N = 152). PEs were measured with Psychosis Screening Questionnaire (PSQ) and subjects who endorsed any item on the PSQ without a clinical diagnosis of psychotic disorder were considered as PE-positive. Types of PEs were characterized using a number of PEs (single v. multiple) and latent class analysis. All PE-positive subjects were assessed with common mental health symptoms and suicidal ideations at baseline and 2-year follow-up. PE status was also assessed at 2-year follow-up.
The 12-month prevalence of PEs in Hong Kong was 2.7% with 21.1% had multiple PEs. Three latent classes of PEs were identified: hallucination, paranoia and mixed. Multiple PEs and hallucination latent class of PEs were associated with higher levels of common mental health symptoms. PE persistent rate at 2-year follow-up was 15.1%. Multiple PEs was associated with poorer mental health at 2-year follow-up.
Results highlighted the transient and heterogeneous nature of PEs, and that multiple PEs and hallucination subtype of PEs may be specific indices of poorer common mental health.
The oxidation behavior of the selective laser melting (SLM)–fabricated Inconel 718 was investigated through isothermal oxidation testing at 650 °C for 500 h and compared with that of the as-cast and as-forged specimens at the same testing conditions. The effect of microstructure and surface roughness on the oxidation behavior of the SLM-fabricated, as-cast, and as-forged Inconel 718 specimens was examined. The result shows that Inconel 718 fabricated by SLM with the unique layer structure exhibited a better resistance to the 500 h oxidation at 650 °C compared with as-cast and as-forged 718 with coarse dendritic structure and uniform equiaxed grain microstructure, respectively. The influence of the surface roughness on the long-time oxidation resistance of SLM specimens is not pronounced compared with that of as-cast and as-forged specimens. The tiny dendrites instead of grain boundaries are a major influencing factor for the oxidation process of SLM specimens. The surface roughness has more evident influence on the oxidation resistance of as-forged specimens than that of the as-cast ones subjected to the 500 h oxidation at 650 °C.
To assess the prevalence and to identify the associated factors of malnutrition among elderly Chinese with physical functional dependency.
Face-to-face interviews using standardised questionnaires were conducted to collect demographic information, health-related issues and psychosocial status. Physical function was measured by the Barthel Index (BI), and nutrition status was assessed by the Mini Nutritional Assessment–Short Form. Multivariate binary logistic regression was used to assess associated factors of malnutrition.
A total of 2323 participants (aged ≥ 60 years) with physical functional dependency in five provinces in China were enrolled using a multistage cluster sampling scheme.
The prevalence of malnutrition was 17·9 % (95 % CI 16·3, 19·4). Multivariable binary logistic regression revealed the independent risk factors of poor nutrition status were being female, older age, lower educational status, poor hearing, poor physical functional status, lack of hobbies, low religious participation, poor social support, lack of social participation and changes in social participation. The study found that the most significant independent risk factor for malnutrition was complete physical functional dependence (OR 4·46, 95 % CI 2·92, 6·82).
The findings of the study confirm that malnutrition and the risk of malnutrition are prevalent in Chinese older adults with physical functional dependency. In addition to demographic and physical health-related factors, psychosocial factors, which are often overlooked, are independently associated with nutrition status in Chinese older adults with physical functional dependency. A holistic approach should be adopted to screen for malnutrition and develop health promotion interventions in this vulnerable population.
The core toroidal plasma intrinsic rotation has been studied by experiments and simulations in the Joint Texas Experimental Tokamak (J-TEXT). The direction of core intrinsic rotation in the J-TEXT plasma is counter-current. As the plasma density ramps up, the rotation velocity increases in the counter-current direction. By comparing four different electron densities, linear local gyrokinetic simulations have been performed by the Gyrokinetic Electromagnetic Numerical Experiment code for the first time on J-TEXT. It is found that the most dominant turbulence is the ion temperature gradient at
is the minor radius of the plasma and this is unchanged during the plasma density ramp up. By scanning the radial wave vectors, it is found that the residual stress term reverses from negative to positive when the plasma density exceeds a certain threshold. The pinch term is larger than the residual stress term at all four electron densities, which means that the pinch term is always dominant in the core of a J-TEXT plasma.
Helicity, as one of only two inviscid invariants in three-dimensional turbulence, plays an important role in the generation and evolution of turbulent flows. Through theoretical analyses, we find that there are two channels in the helicity cascade process, which differs dramatically from the traditional viewpoint. In this paper, we have conducted important research on the newly proposed dual-channel helicity cascade theory, including vortex dynamic processes, intermittent discrepancies, tensor geometries, etc. The first channel mainly originates from the vortex twisting process, and the second channel mainly originates from the vortex stretching process. Antisymmetric tensors are introduced to the derivations of dual-channel helicity cascade theory, and a complex rotation frame leads to a higher helicity transfer efficiency. By analysing data from direct numerical simulations of typical turbulent flows, we find that these two channels behave differently. The ensemble averages of helicity flux in different channels are equal in homogeneous and isotropic turbulence, while they are different in other types of turbulent flows. The intermittency of the second channel is stronger than that of the first channel. In addition, we find a novel mechanism of hindered or even inverse energy cascades, which could be attributed to the second-channel helicity flux.
Physicians' attitudes and adoption behavior toward the delivery of prenatal tests take vital significance for its influence on their professional practice and patient acceptance. This study aimed to identify how physicians have perceived the diffusion of non-invasive prenatal testing (NIPT) in China.
A cross-sectional study was conducted from July 2016 to October 2016 in Shanghai, and Fujian and Sichuan Provinces in China. Physicians working on prenatal screening completed a self-report questionnaire. Following Roger's diffusion of innovation model, multivariable logistic regressions were performed separately for the following key elements of the theory which influence diffusion: physician-perceived attributes of NIPT, communication channels, the nature of the social system, the extent of change agent (who introduces innovations into a society), promotion efforts, and physicians' benefits from adopting NIPT.
Most specialists had a positive attitude (53.2 percent) toward NIPT, whereas 58.9 percent of physicians had already adopted NIPT in their clinical practice. Physician adoption of NIPT was positively associated with the strength of HTA evidence (p = .03), perceived communication frequency with colleagues (p = .04), adoption by other physicians (p = .07), hospital competition (p = .06), hospital teaching status (p = .02), perceived for-profit genetic testing company's promotion (p < .001), and perceived clinical practice skill improvement (p = .02). However, the adoption behavior toward NIPT may be negatively associated with physician-perceived ethical concerns of NIPT (p = .06).
Obstetricians and gynecologists’ positive perceptions facilitate the adoption of NIPT. Combined with cost-effectiveness analysis of prenatal screening methods, health policy makers can promote the adoption of appropriate, cost-effective prenatal screening in pregnant women.
To explore the scope of metabolic syndrome (MetS) and its relationship to the major dietary patterns among an urbanised and semi-urbanised Tibetan population in transition from nomadic to settled settings.
Urbanised and semi-urbanised Tibetan adults (n 920, aged 18–90 years), who have moved from nomadic to settled living environments, answered questionnaires on food consumption frequency and lifestyle characteristics through structured face-to-face interviews and completed anthropometric measurement and metabolic biomarker tests.
MetS prevalence was 30·1 % in males and 32·1 % in females. Low HDL-cholesterol and central obesity were the leading metabolic abnormalities (86·3 and 55·8 %, respectively). Three major dietary patterns – urban, western and pastoral – were identified. Beef/mutton was an important food group for all three identified dietary patterns. In addition, the urban dietary pattern was characterised by frequent consumption of vegetables, tubers/roots and refined carbohydrates; the western pattern was characterised by sweetened drinks, snacks and desserts; and the pastoral pattern featured tsamba (roasted Tibetan barley), Tibetan cheese, butter tea/milk tea and whole-fat dairy foods. Individuals in the highest quintile of urban dietary pattern scores were found to be at a higher risk of developing MetS (OR 2·43, 95 % CI 1·41, 4·18) and central obesity (OR 1·91, 95 % CI 1·16, 3·14) after controlling for potential confounders.
MetS was common among urbanised and semi-urbanised Tibetan adult population in transition. The urban dietary pattern, in particular, was a risk factor for MetS. To prevent MetS, nutrition interventions need to be tailored to address the variety of local diet patterns to promote healthy eating.
We aimed to explore and create an evaluation model to assess hospital response capability for a public health emergency (PHE).
Grounded theory was used to construct a comprehensive evaluation index system. Combining with the index system and previous studies and policy documents, we investigated surge capability of hospitals in a PHE. The factor analysis method was used to establish the model.
The comprehensive evaluation system with 11 primary and 30 secondary indicators was constructed. A total of 89 secondary and tertiary hospitals were surveyed in China. The evaluation model (C = 0.587C1 + 0.151C2 + 0.140C3 + 0.122C4) was established. Four factors were identified, namely, preparation factor, treatment factor, emergency awareness factor, and prehospital first-aid factor.
A public health emergency could bring huge losses and a capable hospital response was necessary. There was an urgent need to evaluate hospital capability for a PHE.
There seems to be geographical differences in decisions about breast conserving surgery (BCS) in breast cancer patients. This study was to evaluate patients’ attitude to BCS and to assess the factors affecting cancer practice in West China.
A structured questionnaire was distributed to 184 patients, eliciting information about the patients’ characteristics, occupation, education, family life, recognition of illness, knowledge about BCS, the main means of gaining surgery information, selecting surgery approaches, preferences to breast reservation.
In all, 163 patients completed the questionnaire. The results indicated that only 7.4% of patients received BCS and 23% of the remaining patients desired to have BCS and the affecting factors were significantly associated with their family life, recognition of illness and the main means of gaining surgery information (P < 0.05). No associations were between BCS selecting and the other variables studied. The most frequent reasons for selecting BCS were keeping the female shape and improving quality of life (71%), the second most were postoperative recovery, minimal influence of physical function (47%) and patients’ knowledge about BCS (42%). The most frequent reasons for not selecting BCS were uncertainty about BCS results and worry about recurrence (81%), the second most was the elderly age unnecessary for BCS (40%).
The findings indicate that breast cancer patients in West China do not take BCS as the first choice as the best treatment method. It is warranted that further study of more patients, attitude of patients’ partners and physicians to BCS.