Search

As a ceramic material, AlN has very good thermophysical and mechanical properties. In addition, AlN is an effective refining agent for Mg alloys because it has a lattice constant similar to that of Mg. Therefore, AlN is an ideal reinforcement for magnesium matrix composites (MMCs), and is attracting increasing attention. This review addresses the development of preparation technologies for AlN-reinforced Mg matrix composites. The mainstream preparation techniques include stir casting, melt infiltration, powder metallurgy, and in-situ methods. In addition, the advantages and disadvantages of these techniques are analyzed in depth, and it is pointed out that the next direction for the preparation of high-performance AlN-reinforced MMCs is less aluminization and multiple technologies integration. [ABSTRACT FROM AUTHOR]

Objectives: Multiple observational studies have shown that low serum level of 25-hydroxyvitamin D (25(OH)D) in patients with chronic kidney disease (CKD) have been associated with a faster progression of kidney disease and a higher risk of all-cause mortality. We aim to assess the association between dietary inflammatory index (DII) with Vitamin D in adults with CKD. Method: The National Health and Nutrition Examination Survey appropriated participants from 2009 to 2018 were enrolled. The patients who were under the age of 18, pregnant, and having incomplete data were excluded. DII score were calculated based on a single 24-h dietary recall interview for each participant. Mutivariable regression analysis and subgroup analysis were utilized to determine the independent associations between vitamin D with DII in CKD patients. Results: In total, 4283 individuals were finally included. The results showed a negative association between DII scores and 25(OH)D with statistical significance (β = – 1.83, 95% CI – 2.31, – 1.34, P < 0.001). In subgroup analysis stratified by gender, low eGFR, age and diabetes, the negative association between DII scores and 25(OH)D was still significant (all P for trend < 0.05). The results from interacion test indicated that the magnitude of the association was the same for the population with and without low eGFR (P for interacion = 0.464). Conclusion: Higher consumption of pro-inflammatory diet correlates negatively with the 25(OH)D level in CKD patients with and without low eGFR. Anti-inflammatory diet management may reduce the reduction of vitamin D in CKD patients. [ABSTRACT FROM AUTHOR]

Economic growth target management is a government behavior that the authorities formulate at a specific time and direct the allocation of resources. Despite the importance of socio-economic development, economic growth targets have caused some potential hazards to the environment that cannot be ignored. Using a panel dataset of 278 prefecture-level cities in China over the period 2004–2019, the study employed a two-way fixed effects model to verify the inhibition effect of economic growth targets on green technology innovation (GTI). The results indicated that economic growth targets and hard constraints tended to have a significantly negative effect on GTI. More importantly, the results of the mediation effect test suggested a positive correlation between economic growth targets and the government fiscal expenditures and market segmentation, and both mediators played an intermediary role in the influence of economic growth target constraints restraining GTI. Other findings showed that the economic growth targets of prefecture-level cities had different impacts on GTI, which resulted from the different resource endowments, geographic locations, or periods. Overall, the results suggest that policymakers should lower the economic growth targets and use soft constraints to set them. The conclusions of this paper are applicable to policymakers not only in China but also other economies that regularly set economic growth targets. [ABSTRACT FROM AUTHOR]

Although several synthesis methods for asynchronous circuits exist, only limited test methodologies have been developed. This paper presents a built-in self-test (BIST) architecture for Multi-Threshold NULL Convention Logic (MTNCL) asynchronous circuits that utilizes an automated, industry-standard tool-based flow. The software procedure for, and hardware components to implement, BIST functionality are explained. To improve testing performance, the MTNCL pipeline is separated into multiple parallel BIST circuits, with standard pipeline components doubling as BIST circuitry to reduce area overhead. Results of this BIST architecture and software performance is explored for three different test cases looking at area impact and effects of varying the number of input patterns and initial seeds. Further refinements to fault exclusions based upon operating principles of MTNCL are developed to better depict actual fault coverage; and additional hardware modifications are proposed to improve controllability and observability to further increase fault coverage. [ABSTRACT FROM AUTHOR]

A potassium-doped carbon nitride (K-CN) was prepared by a simple thermal polymerization method. The prepared K-CN was characterized by Fourier infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) techniques. The obtained K-CN exhibited excellent catalytic activity for synthesis of 4H-chromene derivatives via one-pot three-component reaction of salicylaldehyde, cyclohexane-1,3-diones and 4-hydroxycoumarin in water/ethyl lactate at room temperature. The reported method shows significant advantages, such as high yield, mild and clean reaction conditions, the use of recyclable catalyst and ethyl lactate/water as an environmentally friendly solvent, multi-component reaction at room temperature, no chromatographic separation and suitable for large-scale synthesis. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central South University is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To compare rib fracture detection and classification by radiologists using CT images with and without a deep learning model. Materials and methods: A total of 8529 chest CT images were collected from multiple hospitals for training the deep learning model. The test dataset included 300 chest CT images acquired using a single CT scanner. The rib fractures were marked in the bone window on each CT slice by experienced radiologists, and the ground truth included 861 rib fractures. We proposed a heterogeneous neural network for rib fracture detection and classification consisting of a cascaded feature pyramid network and a classification network. The deep learning-based model was evaluated based on the external testing data. The precision rate, recall rate, F1-score, and diagnostic time of two junior radiologists with and without the deep learning model were computed, and the Chi-square, one-way analysis of variance, and least significant difference tests were used to analyze the results. Results: The use of the deep learning model increased detection recall and classification accuracy (0.922 and 0.863) compared with the radiologists alone (0.812 vs. 0.850). The radiologists achieved a higher precision rate, recall rate, and F1-score for fracture detection when using the deep learning model, at 0.943, 0.978, and 0.960, respectively. When using the deep learning model, the radiologist's reading time was decreased from 158.3 ± 35.7 s to 42.3 ± 6.8 s. Conclusion: Radiologists achieved the highest performance in diagnosing and classifying rib fractures on CT images when assisted by the deep learning model. [ABSTRACT FROM AUTHOR]

Objectives: To develop radiomics-based nomograms for preoperative microvascular invasion (MVI) and recurrence-free survival (RFS) prediction in patients with solitary hepatocellular carcinoma (HCC) ≤ 5 cm. Methods: Between March 2012 and September 2019, 356 patients with pathologically confirmed solitary HCC ≤ 5 cm who underwent preoperative gadoxetate disodium–enhanced MRI were retrospectively enrolled. MVI was graded as M0, M1, or M2 according to the number and distribution of invaded vessels. Radiomics features were extracted from DWI, arterial, portal venous, and hepatobiliary phase images in regions of the entire tumor, peritumoral area ≤ 10 mm, and randomly selected liver tissue. Multivariate analysis identified the independent predictors for MVI and RFS, with nomogram visualized the ultimately predictive models. Results: Elevated alpha-fetoprotein, total bilirubin and radiomics values, peritumoral enhancement, and incomplete or absent capsule enhancement were independent risk factors for MVI. The AUCs of MVI nomogram reached 0.920 (95% CI: 0.861–0.979) using random forest and 0.879 (95% CI: 0.820–0.938) using logistic regression analysis in validation cohort (n = 106). With the 5-year RFS rate of 68.4%, the median RFS of MVI-positive (M2 and M1) and MVI-negative (M0) patients were 30.5 (11.9 and 40.9) and > 96.9 months (p < 0.001), respectively. Age, histologic MVI, alkaline phosphatase, and alanine aminotransferase independently predicted recurrence, yielding AUC of 0.654 (95% CI: 0.538–0.769, n = 99) in RFS validation cohort. Instead of histologic MVI, the preoperatively predicted MVI by MVI nomogram using random forest achieved comparable accuracy in MVI stratification and RFS prediction. Conclusions: Preoperative radiomics-based nomogram using random forest is a potential biomarker of MVI and RFS prediction for solitary HCC ≤ 5 cm. Key Points: • The radiomics score was the predominant independent predictor of MVI which was the primary independent risk factor for postoperative recurrence. • The radiomics-based nomogram using either random forest or logistic regression analysis has obtained the best preoperative prediction of MVI in HCC patients so far. • As an excellent substitute for the invasive histologic MVI, the preoperatively predicted MVI by MVI nomogram using random forest (MVI-RF) achieved comparable accuracy in MVI stratification and outcome, reinforcing the radiologic understanding of HCC angioinvasion and progression. [ABSTRACT FROM AUTHOR]

Objective: To explore the value of texture analysis based on diffusion-weighted imaging (DWI), blood oxygen level-dependent MRI (BOLD), and susceptibility-weighted imaging (SWI) in evaluating renal dysfunction.Methods: Seventy-two patients (mean age 53.72 ± 13.46 years) underwent MRI consisting of DWI, BOLD, and SWI. According to their estimated glomerular filtration rate (eGFR), the patients were classified into either severe renal function impairment (sRI, eGFR < 30 mL/min/1.73 m2), non-severe renal function impairment (non-sRI, eGFR ≥ 30 mL/min/1.73 m2, and < 80 mL/min/1.73 m2), or control (CG, eGFR ≥ 80 mL/min/1.73 m2) groups. Thirteen texture features were extracted and then were analyzed to select the most valuable for discerning the three groups with each imaging method. A ROC curve was performed to compare the capacities of the features to differentiate non-sRI from sRI or CG.Results: Six features proved to be the most valuable for assessing renal dysfunction: 0.25QuantileDWI, 0.5QuantileDWI, HomogeneityDWI, EntropyBOLD, SkewnessSWI, and CorrelationSWI. Three features derived from DWI (0.25QuantileDWI, 0.5QuantileDWI, and HomogeneityDWI) were smaller in sRI than in non-sRI; EntropyBOLD and CorrelationSWI were smaller in non-sRI than in CG (p < 0.05). 0.25QuantileDWI, 0.5QuantileDWI, and HomogeneityDWI showed similar capacities for differentiating sRI from non-sRI. Similarly, EntropyBOLD and CorrelationSWI showed equal capacities for differentiating non-sRI from CG.Conclusion: Texture analysis based on DWI, BOLD, and SWI can assist in assessing renal dysfunction, and texture features based on BOLD and SWI may be suitable for assessing renal dysfunction during early stages.Key Points: • Texture analysis based on MRI techniques allowed for assessing renal dysfunction. • Texture features based on BOLD and SWI, but not DWI, may be suitable for assessing renal function impairment during early stages. • SWI exhibited a similar capacity to BOLD for assessing renal dysfunction. [ABSTRACT FROM AUTHOR]

Background: Ambulatory blood pressure (ABP) monitoring and carotid-femoral pulse wave velocity (cfPWV) provide important cardiovascular risk information for dialysis patients. This study aims to evaluate the risk factors of cfPWV and the associations between ambulatory blood pressure, especially night-time blood pressure and cfPWV.Methods: We conducted a cross-sectional study in patients on maintenance hemodialysis. ABP and cfPWV were measured on a midweek interdialytic day. Associations were determined using Pearson’s correlation analysis and multiple stepwise regression model.Results: Systolic BPs and pulse pressures, but not diastolic BPs, were significantly and positively associated with cfPWV. In a stepwise regression model, age, diabetes mellitus and all-period systolic BP were independently associated with cfPWV. When day-time and night-time BPs were included in the analysis, respectively, only night-time systolic BP and age remained as independently associated with cfPWV.Conclusion: Ambulatory BPs are potent associates of cfPWV and night-time systolic BP, rather than day-time BPs, is an independently predictor of cfPWV. Our results support the view that controlling of nocturnal hypertension provides a unique cardiovascular protection effect. [ABSTRACT FROM AUTHOR]

Esophageal adenocarcinoma (EAC) is one of the most common malignancies in the world which is associated the increased prevalence of obesity. In the context of obesity, leptin can directly contribute to progression of EAC. Adiponectin inhibits leptin-induced oncogenic signaling in EAC cells. However, the exact molecular mechanisms linking obesity, adipokines, and EAC remain far from completely understood. In the present study, we tested the role of ubiquitin-like with PHD and ring finger domains 1 (UHRF1) in adiponectin-induced protective effects against leptin-induced EAC cell proliferation. We found that globular adiponectin (gAD) significantly inhibited leptin-induced increase of cell proliferation and decrease of apoptosis in OE 19 cells. Moreover, leptin-induced increase of UHRF1 expression was suppressed by gAD. Compared with normal controls, UHRF1 expression was markedly increased in EAC tissues and cell lines. Silence of UHRF1 increased the expression of cleaved caspase 3 and 9 and Bax, reduced the expression of Bcl-2, promoted apoptosis, and inhibited cell proliferation in OE 19 cells. Overexpression of UHRF1 significantly blocked gAD-induced decrease of cell proliferation and increase of apoptosis in leptin-treated cells. Silence of adiponectin receptor 1/2 (AdipoR1/2) could inhibit gAD-induced decrease of cell proliferation and increase of apoptosis in leptin-treated cells. Silence of AdipoR2, but not AdipoR1, suppressed gAD-induced decrease of UHRF1 expression in leptin-treated cells. The results indicated that gAD inhibited the prooncogenic effects of leptin via AdipoR2-mediated suppression of UHRF1. Our study provides novel insights into the role of UHRF1 in the development of EAC and the mechanism of antitumor effect of gAD. [ABSTRACT FROM AUTHOR]

Barrett's esophagus (BE) is generally accepted as the only precursor to esophageal adenocarcinoma (EAC). Deoxycholic acid (DCA)-induced inflammation and apoptotic resistance play an important role in the carcinogenesis and progression from BE to EAC. Diallyl disulfide (DADS) is a garlic-derived natural organosulfur compound. This study investigated whether DADS has chemopreventive effects against BE and the potentially related signaling pathway. BAR-T cells were treated with DCA in the presence or absence of DADS. An MTT assay was used to detect the viability of the cells. The apoptosis rate of the cells was measured by light microscopy and flow cytometry. ROS levels were determined by fluorescence microscopy and flow cytometry. Real-time PCR and ELISA were used to detect mRNA and protein levels, respectively. The levels of target proteins were also determined by western blot analysis. DADS did not inhibit cell viability in a certain concentration range. DADS, similar to the NF-κB inhibitor PDTC, inhibited the DCA-induced ROS production, inflammatory factors, IκBα phosphorylation, and expression of p50 in the nucleus in a dose-dependent manner. DADS also increased the cell apoptosis rate through down-regulating the level of Bcl-2. DADS has low cytotoxicity in BAR-T cells. It has an anti-inflammatory effect in BAR-T cells through inhibiting ROS and the NF-κB signaling pathway. Further, it abolishes the apoptotic resistance induced by DCA in an NF-κB/Bcl-2 dependent manner. DADS may be a good candidate for BE and EAC chemical prevention and therapy. [ABSTRACT FROM AUTHOR]

In this paper, powder metallurgy technology combined with high-pressure sintering (HPS) were used to fabricate MnTe ( x = −0.02, 0, 0.04) alloys at 743 K. The products of synthesis were identified by x-ray diffraction; microstructures were examined by field-emission scanning electron microscopy (FE-SEM); the electrical conductivity and the Seebeck coefficient were measured in the temperature range of 300-800 K. The results show that all HPS samples consisted of nanoparticles. MnTe ( x = −0.02, 0, 0.04) thermoelectric materials with a high Seebeck coefficient and low electrical conductivity have potential to warrant further study in the future. The peak figure of the merit, ZT, reaches 0.59 for MnTe at 773 K. [ABSTRACT FROM AUTHOR]

Cavitation bubble collapse has a great influence on the temperature of hydraulic oil. Herein, cone-type throttle valve experiments are carried out to study the thermodynamic processes of cavitation. First, the processes of growth and collapse are analysed, and the relationships between the hydraulic oil temperature and bubble growth and collapse are deduced. The effect of temperature is then considered on the hydraulic oil viscosity and saturated vapour pressure. Additionally, an improved form of the Rayleigh-Plesset equation is developed. The effect of cavitation on the hydraulic oil temperature is experimentally studied and the effects of cavitation bubble collapse in the hydraulic system are summarised. Using the cone-type throttle valve as an example, a method to suppress cavitation is proposed. [ABSTRACT FROM AUTHOR]

Purpose: To investigate whether low b-factors-based apparent diffusion coefficient (ADC) is helpful in assessing renal dysfunction. Materials and methods: Forty-four subjects were recruited, and classified as having severe renal injury group (sRI) or not (non-sRI) according to a threshold of estimated glomerular filtration rate (eGFR) = 30 ml/min/1.73 m. A free-breathing DWI with 7 b-factors (0, 20, 40, 80, 200, 400, and 800 s/mm) was performed. After choosing an anatomical section that covered the largest part of right kidney, the regions of interest covered the renal parenchyma. For each subject, two apparent diffusion coefficients based on all b-factors less than 400 s/mm (ADC) and 800 s/mm (ADC) were calculated by fitting the signal intensity at different b-factors to a mono-exponential decay, respectively. It was found that the examination time of the free-breathing DWI sequence in this study can be reduced from 3.27 to 2.55 min if the b-factor (800 s/mm) is removed. Results: ADC was larger than ADC in each group ( P < 0.05). Both ADC and ADC were smaller in the sRI group than those in the non-sRI group ( P < 0.01), and they were linearly related with eGFR ( P < 0.05). While a significant difference was not found between the two coefficients to differentiate sRI from non-sRI participants ( P > 0.05), a strong correlation was present between ADC and ADC ( r = 0.856, P < 0.001). Conclusion: The low b-factors-based ADC was an economical option for reducing the examination time without sacrificing its diagnostic performance. [ABSTRACT FROM AUTHOR]

Background: Previous observational studies using differing methodologies have yielded inconsistent results regarding the association between glycemic control and outcomes in diabetic patients receiving maintenance hemodialysis (MHD). The aim of this study was to investigate the association between HbA1c and survival in diabetic MHD patients in Han Chinese population. Methods: A 5-year cohort (October 2007-December 2013) of 236 diabetic MHD patients with HbA1c data was examined for associations between HbA1c and mortality. Death hazard ratios (HR) were estimated using Cox regressions. Results: Two hundred and thirty-six diabetes patients undergoing MHD in clinics over 5 years were included in our study. Unadjusted survival analyses indicated paradoxically lower death HRs with higher HbA1c values. However, after adjusting for potential confounders (demographics, dialysis vintage, comorbidity, anemia, and inflammation), higher HbA1c values were incrementally associated with higher death risks. Conclusions: Poor glycemic control (HbA1c ≥ 8 %) appears to be associated with decreased survival in the general population of diabetic MHD patients. Our study suggests that moderate hyperglycemia increases the risk for all-cause mortality of diabetic MHD patients in Han Chinese population. [ABSTRACT FROM AUTHOR]

Heterogeneous catalytic reactions are commonly occurring on the surface of a finely dispersed catalyst. Here, evidence is presented that platinum on a gadolinium doped ceria matrix is present as individual Pt2+ ions, which catalyze the partial oxidation of hydrocarbon molecules. Similarly, ruthenium substituted on the “B” site of LaCrO3 is shown to oscillate between the plus three and zero oxidation states when exposed to a flowing stream of hydrocarbons, steam and air. In both cases, single hetero ions in a host lattice facilitate the catalytic reaction. [ABSTRACT FROM AUTHOR]

Grafting reaction of methyltriethoxysilane on sepiolite surface was studied. The structure of the salinized product before and after thermal treatment was characterized by XRD, TG-DTA, SEM and IR. It is found that the silicon monomers are grafted on the external surface of sepiolite via silicon hydroxyls. The thermal stability remains unchanged after silanization. [ABSTRACT FROM AUTHOR]

This corrects the article DOI: 10.1038/ncomms15938 [ABSTRACT FROM AUTHOR]

For the large-scale sustainable implementation of polymer electrolyte membrane fuel cells in vehicles, high-performance electrocatalysts with low platinum consumption are desirable for use as cathode material during the oxygen reduction reaction in fuel cells. Here we report a carbon black-supported cost-effective, efficient and durable platinum single-atom electrocatalyst with carbon monoxide/methanol tolerance for the cathodic oxygen reduction reaction. The acidic single-cell with such a catalyst as cathode delivers high performance, with power density up to 680 mW cm−2 at 80 °C with a low platinum loading of 0.09 mgPt cm−2, corresponding to a platinum utilization of 0.13 gPt kW−1 in the fuel cell. Good fuel cell durability is also observed. Theoretical calculations reveal that the main effective sites on such platinum single-atom electrocatalysts are single-pyridinic-nitrogen-atom-anchored single-platinum-atom centres, which are tolerant to carbon monoxide/methanol, but highly active for the oxygen reduction reaction. [ABSTRACT FROM AUTHOR]

Developing low-cost diesel-reforming catalysts and improving fuel mixing prior to catalytic reforming were addressed as two critical issues under the current study. Ruthenium-doped lanthanum chromite and aluminite were explored as catalysts for the autothermal reforming of diesel fuel. Dodecane was used as a surrogate fuel. Both catalysts yielded nearly 20 moles of hydrogen per mole of dodecane at oxygen-to-carbon ratios of 0.5 and steam-to-carbon ratios of 2 at space velocities near 100,000/h-1. Both catalysts were shown to have good S tolerance when tested with a fuel mixture containing 50 parts per million S in the form of dibenzothiophene. Parallel to catalyst development, the impact of fuel mixing and vaporization through improved liquid injection also is under investigation. [ABSTRACT FROM AUTHOR]