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This paper presents an eight wire-driven parallel robot (WDPR-8) designed to serve as a suspension manipulator for aircraft models during wind tunnel testing. The precision of these tests is significantly influenced by the system’s stability and workspace, both of which are shaped by the geometric configuration of the structure and the tension in the wires. To acquire the efficiency principle of the suspension scheme design for the model, a kinematics model for a WDPR-8 was established. Based on the kinematics model, the stiffness of a WDPR-8 was theoretically studied, and the analytical expression of stiffness matrix of a WDPR was deduced. The stiffness matrix was composed of two terms, one of which is determined by the configuration of suspension system and the other term is determined by the wire tension. Based on the analysis result, a set of suspension scheme was discussed under the calculation of stiffness matrix and workspace analysis. In the discussion process, in addition to the stiffness-maximum calculation, another criterion as force closure is presented, which is useful for increasing the stiffness and workspace of the robot. Finally, a prototype was established according to the analysis result, and the workspace experiments are conducted. Test results indicate that the workspace meets the design requirements, validating the system suspension design method of a WDPR for aircraft model suspension in wind tunnel test considering of the systematic stiffness and workspace.
A compact 12-element multiple-input multiple-output loop antenna array for a fifth-generation (5G) mobile phone is proposed. The operating band for the proposed antenna covers the long-term evolution 42 band, which spans a frequency range of 3.4–3.6 GHz. The size of the single antenna element is 5.85 × 4.9 mm2 (0.068λ0 × 0.057λ0), and 12 of these elements are positioned along two side edges of the mobile phone. This antenna is suitable for high screen-to-body ratio devices. The measured 6-dB impedance bandwidth is from 3.4 to 3.73 GHz. The measured total efficiency of the proposed antenna is 39–56% and the peak gain is 0–3.2 dBi. The transmission coefficient is less than −12 dB, the envelope correlation coefficient is less than 0.42, and the channel capacity is 45–50 bps/Hz.
According to the public data collected from the Health Commission of Gansu Province, China, regarding the COVID-19 pandemic during the summer epidemic cycle in 2022, the epidemiological analysis showed that the pandemic spread stability and the symptom rate (the number of confirmed cases divided by the sum of the number of asymptomatic cases and the number of confirmed cases) of COVID-19 were different among 3 main epidemic regions, Lanzhou, Linxia, and Gannan; both the symptom rate and the daily instantaneous symptom rate (daily number of confirmed cases divided by the sum of daily number of asymptomatic cases and daily number of confirmed cases) in Lanzhou were substantially higher than those in Linxia and Gannan. The difference in the food sources due to the high difference of the population ethnic composition in the 3 regions was probably the main driver for the difference of the symptom rates among the 3 regions. This work provides potential values for prevention and control of COVID-19 in different regions.
This article presents a qualitative empirical study of elite collusion and its influence on village elections and rural land development in China. Drawing on ethnographic data collected from two Chinese villages, it investigates how village cadres collude with other rural elites, using bribery, gift-giving and lavish banquets, to establish reciprocal ties with township officials and other public officials. Meanwhile, the officials make use of formal organizations to corruptly obtain profits and form alliances with village elites. The article examines how rural elites, especially village cadres, use this collusion to profit from the misuse of villagers’ collectively owned assets, the manipulation of village elections and the suppression of anti-corruption protests. It also offers new descriptive evidence of how recent reforms designed to strengthen the Party's overall leadership in rural governance may have actually facilitated elite capture and grassroots corruption.
This research commentary responds to Jiang and Murmann (2022), by offering further explanations for the miraculous growth of the digital economy in China from both the demand and supply perspectives. To complement their views, we identify several additional important factors, and classify them in three categories in an explanatory model. We believe that factors on the demand side played a primary role, along with innovative and entrepreneurial e-commerce service providers on the supply side. Infrastructures and government policies provided the foundation and a facilitating environment. We conclude that digital transformation of traditional industries will become the next wave of digital economy, stronger than the previous wave of e-commerce. Implications for research and practices are also discussed. In addition, we highlight emerging trends and turbulences. In conclusion, despite short-term turbulences, we expect that the digital economy in China will make big-stride progress in the long term, with strong potential to continue its growth.
This paper studies the joint tail asymptotics of extrema of the multi-dimensional Gaussian process over random intervals defined as
$P(u)\;:\!=\; \mathbb{P}\{\cap_{i=1}^n (\sup_{t\in[0,\mathcal{T}_i]} ( X_{i}(t) +c_i t )>a_i u )\}$
,
$u\rightarrow\infty$
, where
$X_i(t)$
,
$t\ge0$
,
$i=1,2,\ldots,n$
, are independent centered Gaussian processes with stationary increments,
$\boldsymbol{\mathcal{T}}=(\mathcal{T}_1, \ldots, \mathcal{T}_n)$
is a regularly varying random vector with positive components, which is independent of the Gaussian processes, and
$c_i\in \mathbb{R}$
,
$a_i>0$
,
$i=1,2,\ldots,n$
. Our result shows that the structure of the asymptotics of P(u) is determined by the signs of the drifts
$c_i$
. We also discuss a relevant multi-dimensional regenerative model and derive the corresponding ruin probability.
Excessive iodine can lead to goiters. However, the relationship between the water iodine concentration (WIC) and goiter rate (GR) is unclear. This study aims to explore the factors that influence children’s GR in areas with high WIC and analyse the threshold value of the GR increase associated with the WIC. According to the monitoring of the areas with high WIC in China in 2018–2020, a total of 54 050 children in eight high water iodine provinces were chosen. Drinking water, urine and edible salt samples of children were collected. The thyroid volume (Tvol) was measured. A generalised additive model (GAM) was used to analyse the relationship between the WIC and GR in children. Among the 54 050 children in areas with high WIC, the overall GR was 3·34 %, the median of water iodine concentration was 127·0 µg/l, the median of urinary iodine concentration was 318 µg/l and the non-iodised salt coverage rate (NISCR) was 63·51 %. According to the GAM analysis results, water iodine and urinary iodine are factors that influence the Tvol and GR, while the NISCR affects only the GR. When the WIC was more than 420 µg/l or the urinary iodine concentration was more than 800 µg/l, the GR increased rapidly. When the NISCR reached more than 85 %, the GR was the lowest. Thus, in areas with high WIC, WIC more than 420 µg/l may increase the risk of goiter, and the NISCR should be increased to over 85 % to avoid goiters in children.
The association between blood transfusion and ventilator-associated events (VAEs) has not been fully understood. We sought to determine whether blood transfusion increases the risk of a VAE.
Design:
Nested case-control study.
Setting:
This study was based on a registry of healthcare-associated infections in intensive care units at West China Hospital system.
Patients:
1,657 VAE cases and 3,293 matched controls were identified.
Methods:
For each case, 2 controls were randomly selected using incidence density sampling. We defined blood transfusion as a time-dependent variable, and we used weighted Cox models to calculate hazard ratios (HRs) for all 3 tiers of VAEs.
Results:
Blood transfusion was associated with increased risk of ventilator-associated complication-plus (VAC-plus; HR, 1.47; 95% CI, 1.22–1.77; P <.001), VAC-only (HR, 1.29; 95% CI, 1.01–1.65; P = .038), infection-related VAC-plus (IVAC-plus; HR, 1.78; 95% CI, 1.33–2.39; P < .001), and possible ventilator-associated pneumonia (PVAP; HR, 2.10; 95% CI, 1.10–3.99; P = .024). Red blood cell (RBC) transfusion was also associated with increased risk of VAC-plus (HR, 1.34; 95% CI, 1.08–1.65; P = .007), IVAC-plus (HR, 1.70; 95% CI, 1.22–2.36; P = .002), and PVAP (HR, 2.49; 95% CI, 1.17–5.28; P = .018). Compared to patients without transfusion, the risk of VAE was significantly higher in patients with RBC transfusions of >3 units (HR, 1.73; 95% CI, 1.25–2.40; P = .001) but not in those with RBC transfusions of 0–3 units.
Conclusion:
Blood transfusions were associated with increased risk of all tiers of VAE. The risk was significantly higher among patients who were transfused with >3 units of RBCs.
We report an experimental study of the Prandtl-number effects in quasi-two-dimensional (quasi-2-D) Rayleigh–Bénard convection. The experiments were conducted in four rectangular convection cells over the Prandtl-number range of $11.7 \leqslant Pr \leqslant 650.7$ and over the Rayleigh-number range of $6.0\times 10^8 \leqslant Ra \leqslant 3.0\times 10^{10}$. Flow visualization reveals that, as $Pr$ increases from 11.7 to 145.7, thermal plumes pass through the central region much less frequently and their self-organized large-scale motion is more confined along the periphery of the convection cell. The large-scale flow is found to break down for higher $Pr$, resulting in a regime transition in the Reynolds number $Re$. For the $Pr$ range with a large-scale flow of system size, the $Re$ number, Nusselt number $Nu$ and local temperature fluctuations were investigated systematically. It is found that $Re$ scales as $Re \sim Ra^{0.58}Pr^{-0.82}$ in the present geometry, which suggests that it is in line with the behaviour in the 2-D configuration. On the other hand, the measured $Nu(Ra, Pr)$ relation $Nu \sim Ra^{0.289}Pr^{-0.02}$ tends to be compatible with the finding in a three-dimensional (3-D) system. For the temperature fluctuations in the cell centre and near the sidewall, they exhibit distinct $Ra$-dependent scalings that could not be accounted for with existing theories, but their $Pr$ dependences for $Pr \lesssim 50$ are in agreement with the predictions by Grossmann & Lohse (Phys. Fluids, vol. 16, 2004, pp. 4462–4472). These results enrich our understanding of quasi-2-D thermal convection, and its similarities and differences compared to 2-D and 3-D systems.
Manure and chemical fertilizers have different effects on soil properties, the nitrogen cycle, and crop yield. This study aimed to investigate the effects of different fertilizer applications under the same N input on soil physicochemical properties and soil bacterial communities and to explain the contributions of soil properties to grain yield. Manure substitution of chemical fertilizer was conducted in leaching monitoring systems. The study began in 2009 and sampling was carried out in 2014 and 2016. Three fertilizer treatments with the same total N, P, and K application rates and one control treatment were designed as follows: (1) CK, without nitrogen fertilizer; (2) 100%U, whole nitrogen coming from urea; (3) 100%M, whole nitrogen coming from composted cattle manure; and (4) 50%U + 50%M, half nitrogen from composted cattle manure and half nitrogen from urea. Soil organic carbon (SOC) content was positively correlated with total N (TN), NO3−–N, and NH4+–N contents, the mean weight diameter of soil aggregates, and the Shannon diversity index of bacteria, whereas SOC content was not significantly correlated with grain yield. NO3−–N content was positively correlated with grain yield. Substituting half the amount of chemical fertilizer with manure as a nitrogen source improved soil stability, increased bacterial diversity, and enhanced nitrogen supply, while reducing nitrogen loss from ammonia volatilization and nitrogen leaching. Substituting half the amount of chemical fertilizer with manure as a nitrogen source was a more sustainable way to increase grain yield through a sustainable nitrate supply and to reduce N loss.
The edge surface warping defect seriously affect the surface quality of strips. In this paper, a technology for diagnosis of warping defects in hot-rolled strip based on data-driven methods is studied. Based on the mechanism analysis of the warping defects, the process parameters affecting the warping defects were sorted out and used as the original input parameters of the defect diagnosis model. Firstly, a diagnostic model that combines the deep belief network and contribution plots of each dimensionality reduction layer is proposed. The deep belief network that integrates each dimensionality reduction layer can predict product defects more accurately and stably than the traditional deep belief network. Meanwhile, on the basis of the pre-judgment model, the method of contribution plot is further introduced to trace the defects, and the comprehensive diagnosis function of model pre-judgment and traceability is realized. Finally, collected the production data from a hot rolling production line for a period of time. Tested the model and predicted a hit rate of 85%. The main influencing factors of edge surface warping defects were determined that the rate of defect decrease with the increase of furnace temperature. When the heating temperature of the second stage of the heating furnace is higher than 1160°C, the incidence of defects is significantly reduced. Defect rate is relatively low within 240min of total furnace time. With the first and third pass phosphorus removal equipment turned on, the incidence of defects was relatively low.
The study investigated antioxidant effects of Se on resilience to diquat-induced oxidative stress in nursery pigs. Thirty-five weaned pigs were individually housed and randomly assigned to one of the five treatments. Pigs were (1) fed a basal diet and intraperitoneally injected with sterile saline (negative control), (2) fed the basal diet and injected with diquat solution (positive control, PC), or fed the basal diet supplemented with 0·3 mg Se/kg as (3) sodium selenite (SS), (4) soyabean protein-chelated Se (SC) or (5) selenised yeast (SY) and intraperitoneally injected with diquat. Pigs were fed the experimental diets for 17 d and injected with diquat at 10 mg/kg body weight or saline on the 11th day of the study (day 0 post-injection (PI)). Diquat exposure induced acute stress and innate immune activation (P < 0·05) at 6 h PI and compromised (P < 0·05) plasma glutathione peroxidase activity on day 2 PI, which was accompanied by an increase in plasma malondialdehyde at 6 h and day 2 PI (P < 0·10). Organic Se, particularly SY, enhanced (P < 0·05) endogenous antioxidant activity in various aspects compared with the PC group. The growth rate and feed intake from day 0 to day 7 PI were significantly lower in the PC, SS and SC groups than the NC group (P < 0·05). Untargeted metabolomics analysis revealed that twenty-two hepatic metabolites (false discovery rate < 0·15) associated with lipid and cellular antioxidant metabolism were altered by diquat. SY restored hepatic metabolic profiles in some but not all samples.
Ca2+-sensing receptor (CaSR) represents a potential therapeutic target for inflammatory bowel diseases and strongly prefers aromatic amino acid ligands. We investigated the regulatory effects of dietary supplementation with aromatic amino acids – tryptophan, phenylalanine and tyrosine (TPT) – on the CaSR signalling pathway and intestinal inflammatory response. The in vivo study was conducted with weanling piglets using a 2 × 2 factorial arrangement in a randomised complete block design. Piglets were fed a basal diet or a basal diet supplemented with TPT and with or without inflammatory challenge. The in vitro study was performed in porcine intestinal epithelial cell line to investigate the effects of TPT on inflammatory response using NPS-2143 to inhibit CaSR. Dietary supplementation of TPT alleviated histopathological injury and decreased myeloperoxidase activity in intestine challenged with lipopolysaccharide. Dietary supplementation of TPT decreased serum concentration of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-12, granulocyte-macrophage colony-stimulating factor, TNF-α), as well as the mRNA abundances of pro-inflammatory cytokines in intestine but enhanced anti-inflammatory cytokines IL-4 and transforming growth factor-β mRNA levels compared with pigs fed control diet and infected by lipopolysaccharide. Supplementation of TPT increased CaSR and phospholipase Cβ2 protein levels, but decreased inhibitor of NF-κB kinase α/β and inhibitor of NF-κB (IκB) protein levels in the lipopolysaccharide-challenged piglets. When the CaSR signalling pathway was blocked by NPS-2143, supplementation of TPT decreased the CaSR protein level, but enhanced phosphorylated NF-κB and IκB levels in IPEC-J2 cells. To conclude, supplementation of aromatic amino acids alleviated intestinal inflammation as mediated through the CaSR signalling pathway.
Evidence on the association between maternal Hb concentration and preterm birth (PTB) risk is inconclusive. This paper aimed to explore whether women with anaemia or high Hb level before pregnancy would be at higher risk of PTB. We conducted a population-based cohort study with 2 722 274 women aged 20–49 years, who participated in National Free Pre-Pregnancy Checkups Project between 2013 and 2015 and delivered a singleton before 2016 in rural China. Logistic models were used to estimate OR and 95 % CI after adjusting for confounding variables. Restricted cubic spline models were applied to evaluate the dose–response relationships. A total of 192 819 (7·08 %) women had preterm deliveries. Compared with women with Hb of 110–149 g/l, the multivariable-adjusted OR for PTB was 1·19 (95 % CI 0·98, 1·44) for women with Hb<70 g/l, 1·01 (95 % CI 0·97, 1·03) for 70–99 g/l, 0·96 (95 % CI 0·95, 0·98) for 100–109 g/l, 1·04 (95 % CI 1·01, 1·06) for 150–159 g/l, 1·11 (95 % CI 1·05, 1·17) for 160–169 g/l and 1·19 (95 % CI 1·11, 1·27) for ≥170 g/l, respectively. The multivariable-adjusted OR for very PTB (VPTB) was 1·07 (95 % CI 1·03, 1·12) and 1·06 (95 % CI 1·01, 1·12) for women with Hb <110 and ≥150 g/l, compared with those with Hb of 110–149 g/l, respectively. Our study identified a U-shaped relationship between maternal preconception Hb concentration and PTB risk. Both preconception anaemia and high Hb level can significantly increase VPTB risk. Appropriate intervention for women with abnormal Hb levels before pregnancy is very necessary.
Ethanolamine (Etn) contained in milk is the base constituent of phosphatidylethanolamine and is required for the proliferation of intestinal epithelial cells and bacteria, which is important for maintenance of the gut microbiome and intestinal development. The present study investigated the effect of Etn on intestinal function and microbiome using 21-d-old Sprague–Dawley rats treated with 0, 250, 500 and 1000 μm Etn in drinking water for 2 weeks immediately after weaning. Growth performance, intestinal morphology, antioxidant capacity and mucosal immunity, as well as gut microbiota community composition, were evaluated. Metagenomic prediction and metabolic phenotype analysis based on 16S RNA sequencing were also carried out to assess changes in metabolic functions. We found that weaned rats administered 500 μm Etn enhanced mucosal antioxidant capacity, as evidenced by higher superoxide dismutase and glutathione peroxidase levels in the jejunum (P<0·05) compared with those in the control group. Predominant microbes including Bacteroidetes, Proteobacteria, Elusimicrobia and Tenericutes were altered by different levels of Etn compared with the control group. An Etn concentration of 500 µm shifted colonic microbial metabolic functions that are in favour of lipid- and sugar-related metabolism and biosynthesis. Etn also altered the metabolic phenotypes such as anaerobic microbial counts, and oxidative stress tolerance at over 250 µm. This is the first report for a role of Etn in modifying gut microbiota and intestinal functions. Our findings highlighted the important role of Etn in shaping gut microbial community and promotes intestinal functions, which may provide a better insight of breast-feeding to infant’s gut health.
Porous carbon nanomaterials with significant capacitive performance were successfully prepared through a simple two-step process of thermal-polymerization and carbonization without an additional template. As a result, the as-prepared porous carbon nanomaterials of sample-A and sample-B exhibited an amorphous phase with low graphitization. And sample-A showed a moderate specific surface area of 476.39 m2/g, larger than that of sample-B (280.94 m2/g). The relatively high mass specific capacitance of 205.1 F/g at a scan rate of 5 mV/s and 211 F/g at a current density of 4 A/g was obtained by sample-A, which are higher than those of sample-B (82.6 F/g at 5 mV/s and 78.6 F/g at 4 A/g). Sample-A also showed excellent conductivity and superior cyclic stability with 94.19% capacitance retention after 5000 cycles, which are also higher than those of sample-B. This work proposed a cost-effective, green, and promising strategy for the large-scale preparation of porous carbon nanomaterial electrodes.
More than 200 molecular clouds were newly found distributed beyond the Outer arm in the extreme outer Galaxy (EOG) region by MWISP. Those MCs roughly following the HI′s distribution well delineate the outermost spiral structure (the Outer Scutum-Centaurus arm) and warp of our Galaxy. Besides, those MCs show different σv-Radius relation and exhibit higher value of αvir than MCs in the inner Galaxy.
The present study was performed to identify the genotype of a hypertrophic cardiomyopathy family and investigate the clinicopathogenic characteristics and prognostic features of relevant genetic abnormalities. Target sequence capture sequencing was performed to screen for pathogenic alleles in a 32-year-old female patient (proband). Sanger sequencing was carried out to verify the results. Sanger sequencing was also performed on other family members to identify allele carriers. A survival analysis was carried out using published literature and our findings. We found that the proband and her son harboured a Gly716Arg sequence variant of the β-myosin heavy chain. Neither the proband’s father nor the mother were carriers of this sequence variant; thus, the mutation was classified as “de novo”. Further survival analysis revealed that female patients appear to have a longer life expectancy compared with males. Our study may provide an effective approach for the genetic diagnosis of hypertrophic cardiomyopathy.
To examine the vitamin D status, SNP of the vitamin D receptor gene (VDR) and the effects of vitamin D supplementation on parathyroid hormone and insulin secretion in adult males with obesity or normal weight in a subtropical Chinese city.
Design
An intervention trial.
Setting
Shenzhen City, Guangdong Province, China.
Subjects
From a cross-sectional survey conducted from June to July, eighty-two normal-weight and ninety-nine obese males (18–69 years) were screened to analyse their vitamin D status and for five SNP of VDR. From these individuals, in the same season of a different year, obese and normal-weight male volunteers (twenty-one per group) were included for an intervention trial with oral vitamin D supplementation at 1250 µg/week for 8 weeks.
Results
For the survey, there was no significant difference (P>0·05) in baseline circulating 25-hydroxyvitamin D concentrations or in the percentages of participants in different categories of vitamin D status between the two groups. The VDR SNP, rs3782905, was significantly associated with obesity (P=0·043), but none of the examined SNP were correlated with serum 25-hydroxyvitamin D when adjusted for age, BMI and study group. After vitamin D supplementation, serum 25-hydroxyvitamin D concentration, hypersecretions of parathyroid hormone and insulin, and insulin resistance in the obese were changed beneficially (P<0·05); however, the increase in serum 25-hydroxyvitamin D was less than that of the normal-weight men.
Conclusions
For obese and normal-weight men of subtropical China, the summer baseline vitamin D status was similar. However, oral vitamin D supplementation revealed a decreased bioavailability of vitamin D in obese men and ameliorated their hypersecretion of parathyroid hormone and insulin resistance.
In the past 10 years, under the common problems of unemployment of people with a higher education and the devaluation of diplomas, the concepts and practices of higher education governance have emerged and have gradually been embedded in university operations. Higher education in Taiwan faces the same problems as the rest of the world. Thus, guided by policies of the Taiwanese Ministry of Education (TMOE) and fuelled by the media, the education-job gap is becoming a discursive truth. With this background, the TMOE has invested numerous resources to establish an information system (IS) that attempts to guide the direction of university education using information technology. If the IS is poorly designed, the scope of its side effects and harm will be magnified by a massive number of IS users and the characteristics of procedure standardisation. We suggest another form of action — IS competition, in which more positive social changes can be created. Based on the analysis of the available data, the action of IS competition does have a positive impact on society.