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Influence Mechanism of Accelerator on the Hydration and Microstructural Properties of Portland Cement
2024
Shotcrete is one of the most important types of concrete used in engineering construction, and its properties are significantly influenced by accelerators. This study investigates the effects of aluminum sulfate series alkali-free accelerator (AKF) and alkali accelerator (ALK) on the strength, hydration process, characteristic hydration products, and microstructure properties of shotcrete. Techniques such as setting time measurement, isothermal calorimetry, simultaneous thermal analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDS), and mercury intrusion porosimetry (MIP) were utilized. The results indicate that both ALK and AKF significantly accelerate and increase the early hydration heat release rate and cumulative hydration heat of Portland cement, producing the characteristic hydration products hexagonal plate AFm and rod AFt, respectively. This acceleration notably speeds up the setting process of Portland cement. ALK negatively impacts the later-stage microstructural development and pore structure filling of hardened cement paste, leading to average reductions of 15.3% and 19.9% in flexural and compressive strengths at 28 days, respectively. Specifically, compared to ALK, AKF shows a faster hydration heat release rate during the induction period and a more significant increase in cumulative hydration heat during the hydration process; the cumulative hydration heat is on average 18.2% higher than AKF. Furthermore, AKF does not hinder the subsequent C3S hydration and C-S-H gel densification process. After 28 days of curing, EDS analysis indicates an average Ca/Si ratio of 1.171 for the AKF-treated shotcrete; the average Ca/Si ratio shows minimal variation from the reference group and is classified as the same type of C-S-H gel as the reference group. Therefore, the strength of hardened cement paste with AKF continues to increase steadily in the later stages. At 28 days, the average flexural strength increased by 10.2%, while the compressive strength decreased by only 3.0%. These findings suggest that AKF enhances the microstructural development and strength of shotcrete, making it a more effective accelerator for engineering applications.
Journal Article
Mortality risk of patients with intestinal obstruction
2024
Background
Intestinal obstruction represents a severe intestinal disease associated with higher mortality rates. However, the determinants of mortality in patients with intestinal obstruction remain inadequately understood. This study sought to elucidate the potential risk factors associated with mortality in the context of intestinal obstruction during the COVID-19 pandemic.
Methods
A retrospective analysis was performed on a cohort of 227 patients diagnosed with intestinal obstruction at the First Hospital of Hebei Medical University, spanning the period from September 7, 2022, to January 7, 2023. The primary endpoint of the study was mortality within four weeks following discharge. Univariate and multivariable logistic regression models were utilized to evaluate the risk factors associated with mortality outcomes.
Results
A cohort of 227 patients diagnosed with intestinal obstruction (median age, 59.02 years [IQR, 48.95–70.85 years]) was included in our study. Malignant bowel obstruction (MBO) and COVID-19 were identified as independent risk factors for mortality among these patients. Notably, the mortality rate increased significantly to 38.46% when MBO was concomitant with COVID-19. Furthermore, postoperative pulmonary complications (PPC) (OR, 54.21 [death]; 95% CI, 3.17-926.31), gastric cancer (OR, 9.71 [death]; 95% CI, 1.38–68.18), VTE (Caprini Score ≥ 5) (OR, 7.64 [death]; 95% CI, 1.37–42.51), and COVID-19 (OR, 5.72 [death]; 95% CI, 1.01–32.29) were all determined to be independent risk factors for postoperative mortality. Additionally, gastric cancer could have emerged as one of the most severe risk factors for mortality in individuals with intestinal obstruction within the cohort of cancer patients, of which gastric cancer exhibited higher mortality rates compared to individuals with other forms of cancer.
Conclusion
The study identifies MBO, gastric cancer, COVID-19, PPC, and VTE as potential risk factors for mortality in cases of intestinal obstruction. These findings highlight the necessity for continuous monitoring of indicators related to these mortality risk factors and their associated complications, thereby offering valuable insights for the management and treatment of intestinal obstruction.
Journal Article
The Influence and Mechanism of Polyvinyl Alcohol Fiber on the Mechanical Properties and Durability of High-Performance Shotcrete
2024
This study investigates the impact of polyvinyl alcohol (PVA) fibers on the mechanical properties and durability of high-performance shotcrete (HPS). Results demonstrate that PVA fibers have a dual impact on the performance of HPS. Positively, PVA fibers enhance the tensile strength and toughness of shotcrete due to their intrinsic high tensile strength and fiber-bridging effect, which significantly improves the material’s splitting tensile strength, deformation resistance, and toughness, and the splitting tensile strength and peak strain have been found to be increased by up to 30.77% and 31.51%, respectively. On the other hand, the random distribution and potential agglomeration of PVA fibers within the HPS matrix can lead to increased air-void formations. This phenomenon raises the volume content of large bubbles and increases the average bubble area and diameter, thereby elevating the pore volume fraction within the 500–1200 μm and >1200 μm ranges. Therefore, these microstructural changes reduce the compactness of the HPS matrix, resulting in a decrease in compressive strength and elastic modulus. The compressive strength exhibited a reduction ranging from 10.44% to 15.11%, while the elastic modulus showed a decrease of between 8.09% and 12.67%. Overall, the PVA-HPS mixtures with different mix proportions demonstrated excellent frost resistance, chloride ion penetration resistance, and carbonation resistance. The electrical charge passed ranged from 133 to 370 C, and the carbonation depth varied between 2.04 and 6.12 mm. Although the incorporation of PVA fibers reduced the permeability and carbonation resistance of shotcrete, it significantly mitigated the loss of tensile strength during freeze–thaw cycles. The findings offer insights into optimizing the use of PVA fibers in HPS applications, balancing enhancements in tensile properties with potential impacts on compressive performance.
Journal Article
Comprehensive analysis of the differences between left- and right-side colorectal cancer and respective prognostic prediction
2022
Background
Previous studies have reported that the tumor heterogeneity and complex oncogenic mechanisms of proximal and distal colon cancer (CRC) are divergent. Therefore, we aim to analyze the differences between left-sided CRC (L_cancer) and right-sided CRC (R_cancer), as well as constructing respective nomograms.
Methods
We enrolled 335 colon cancer patients (146 L_cancer patients and 189 R_cancer patients) from The Cancer Genome Atlas (TCGA) data sets, and 102 pairs of color cancer tissue and adjacent normal tissue (51 L_cancer patients and 51 R_cancer patients) from our hospital. Firstly, we analyzed the differences between the L_cancer patients and R_cancer patients, and then established the L_cancer and R_cancer prognostic models using LASSO Cox.
Results
R_cancer patients had lower survival than L_cancer patients. R_cancer patients had higher ESTIMATE and immune scores and lower tumor purity. These patterns of expression of immune checkpoint-related genes and TMB level were higher in R_cancer than in L_cancer patients. Finally, we using Lasso Cox regression analyses established a prognostic model for L_cancer patients and a prognostic model for R_cancer patients. The AUC values of the risk score for OS in L_cancer were 0.862 in the training set and 0.914 in the testing set, while those in R_cancer were 0.835 in the training set and 0.857 in the testing set. The AUC values in fivefold cross-validation were between 0.727 and 0.978, proving that the two prognostic models have great stability. The nomogram of L_cancer included prognostic genes, age, pathological M, pathological stage, and gender, the AUC values of which were 0.800 in the training set and 0.905 in the testing set. Meanwhile, the nomogram of R_cancer comprised prognostic genes, pathological N, pathological T, and age, the AUC values of which were 0.836 in the training set and 0.850 in the testing set. In the R_cancer patients, high-risk patients had a lower proportion of ‘B cells memory’, ‘Dendritic cells resting’, immune score, ESTIMATE score, immune checkpoint-related genes, and HLA-family genes, and a higher proportion of ‘T cells follicular helper’, ‘Dendritic cells activated’, and ‘Mast cells activated’.
Conclusions
We found significant differences between L_cancer and R_cancer patients and established a clinical predictive nomogram for L_cancer patients and a nomogram for R_cancer patients. Additionally, R_cancer patients in low-risk groups may be more beneficial from immunotherapy.
Journal Article
Effects of pore scale and conjugate heat transfer on thermal convection in porous media
2022
The study of thermal convection in porous media is of both fundamental and practical interest. Typically, numerical studies have relied on the volume-averaged Darcy–Oberbeck–Boussinesq (DOB) equations, where convection dynamics are assumed to be controlled solely by the Rayleigh number (Ra). Nusselt numbers (Nu) from these models predict Nu–Ra scaling exponents of 0.9–0.95. However, experiments and direct numerical simulations (DNS) have suggested scaling exponents as low as 0.319. Recent findings for solutal convection between DNS and DOB models have demonstrated that the ‘pore-scale parameters’ not captured by the DOB equations greatly influence convection. Thermal convection also has the additional complication of different thermal transport properties (e.g. solid-to-fluid thermal conductivity ratio ks/kf and heat capacity ratio σ) in different phases. Thus, in this work we compare results for thermal convection from the DNS and DOB equations. On the effects of pore size, DNS results show that Nu increases as pore size decreases. Mega-plumes are also found to be more frequent and smaller for reduced pore sizes. On the effects of conjugate heat transfer, two groups of cases (Group 1 with varying ks/kf at σ = 1 and Group 2 with varying σ at ks/kf = 1) are examined to compare the Nu–Ra relations at different porosity (ϕ) and ks/kf and σ values. Furthermore, we report that the boundary layer thickness is determined by the pore size in DNS results, while by both the Rayleigh number and the effective heat capacity ratio, $\\bar{\\phi } = \\phi + (1 - \\phi )\\sigma$, in the DOB model.
Journal Article
Pathogenesis of non-alcoholic fatty liver disease mediated by YAP
2018
ObjectiveThis study aimed to investigate the mechanism of the interaction between Yes-associated protein (YAP) and transforming growth factor-β (TGF-β)/Smad signaling pathways in the development of non-alcoholic fatty liver disease (NAFLD).MethodsSerum samples of monkeys with biopsy-proven NAFLD and healthy normal monkeys were used to measure fasting plasma glucose (FPG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG) and albumin (ALB) with the BECKMAN CX5 PRO. Hematoxylin-eosin staining (H&E) was used for pathologic analysis, Masson trichrome staining was used to assess for fibrosis staging, and Oil Red O staining was used to detect lipid droplet deposition. According to an NAFLD activity score of < 4 points and > 4 points, the samples were divided into groups: the steatosis group and fibrosing NASH group. Furthermore, monkeys with a fibrosis stage < 2 were assigned to the mild fibrosis group, while monkeys with fibrosis stage ≥ 2 were assigned to the significant fibrosis group. Moreover, the fibrosis stage was subdivided as follows: stages 1a, 1c and 2–3. Immunohistochemistry and real-time quantitative PCR were used to quantify protein and gene expression, respectively.ResultsIn the present study, 54 monkeys with NAFLD and 23 normal monkeys were recruited. Serum FPG and TG levels were higher in fibrosing NASH monkeys compared with simple steatosis and normal monkeys, and differences between simple steatosis and normal monkeys were not statistically significant (p > 0.05). YAP increased in NAFLD, which mainly localized in the nuclei of hepatocytes, perivascular cells and bile duct cells; the accumulation of YAP correlated with the severity of hepatocyte injury. Compared with normal monkeys, the expression of TGF-β, α-smooth muscle actin (α-SMA), Drosophila mothers against decapentaplegic protein 3 (Smad3) and connective tissue growth factor (CTGF) in the liver of simple steatosis monkeys significantly increased (p < 0.01). Compared with simple steatosis monkeys, the expression of TGF-β, α-SMA, Smad3 and CTGF in fibrosing NASH significantly increased (p < 0.01). However, the expression of Drosophila mothers against decapentaplegic protein 7 (Smad7) in the liver of fibrosing NASH monkeys significantly decreased (p < 0.01). With the severity of liver fibrosis, the expression of TGF-β, α-SMA, Smad3 and CTGF gradually increased, and the difference was statistically significant (p < 0.01). However, there was no significant difference in the expression of Smad3 between fibrosis stage 1a and 1c. Compared with normal monkeys, the expression of Smad7 in the liver of monkeys with fibrosis significantly decreased (p < 0.01), but was significantly higher at fibrosis stage 1c than at fibrosis stage 1a and 2.ConclusionThe YAP and TGF-β signaling pathways and the interaction between them promote the development and progression of NAFLD.
Journal Article
Anomalous sub-diffusion of water in biosystems: From hydrated protein powders to concentrated protein solution to living cells
by
Takeshi Yamada
,
Zhuo Liu
,
Liang Hong
in
Biological activity
,
Cells (biology)
,
Crystallography
2020
Water is essential to life and its translational motion in living systems mediates various biological processes, including transportation of function-required ingredients and facilitating the interaction between biomacromolecules. By combining neutron scattering and isotopic labeling, the present work characterizes translational motion of water on a biomolecular surface, in a range of systems: a hydrated protein powder, a concentrated protein solution, and in living Escherichia coli (E. coli) cells. Anomalous sub-diffusion of water is observed in all samples, which is alleviated upon increasing the water content. Complementary molecular dynamics simulations and coarse-grained numerical modeling demonstrated that the sub-diffusive behavior results from the heterogeneous distribution of microscopic translational mobility of interfacial water. Moreover, by comparing the experimental results measured on E. coli cells with those from a concentrated protein solution with the same amount of water, we show that water in the two samples has a similar average mobility, however the underlying distribution of motion is more heterogeneous in the living cell.
Journal Article
A village doctor-led mobile health intervention for cardiovascular risk reduction in rural China: cluster randomised controlled trial
2025
AbstractObjectiveTo assess the effectiveness of a village doctor-led mobile health intervention on cardiovascular risk reduction among residents in rural China.DesignCluster randomised controlled trial.Setting127 villages from five provinces and autonomous regions in China.Participants4533 participants from 127 villages: 2297 (64 villages) were randomly assigned to the intervention group and 2236 (63 villages) to the control group. Participants were aged ≥35 years, had no established atherosclerotic cardiovascular disease (ASCVD) but a predicted 10 year risk of ≥10%, had contracted a family doctor service with the local village doctor, and owned a smart phone.InterventionsIn addition to usual clinical care and basic public health services provided for the control group, the intervention led by village doctors included five components: assessing risk factors to identify individualised intervention targets, setting gradual goals based on doctor-participant communication, providing targeted short videos on health education, conducting health monitoring with periodic feedback, and providing motivation to reduce risk based on gamification.Main outcome measureMean change in predicted 10 year risk of ASCVD from baseline to 12 months.ResultsEnrolment took place between March 2023 and May 2023. During the 12 month follow-up (completion rate 99.4%), the 10 year risk of ASCVD decreased from 18.0% to 11.7% in the intervention group and from 17.8% to 13.6% in the control group (absolute difference −1.88% (95% confidence interval (CI) −2.57% to −1.19%; P<0.001). Compared with the control group, the intervention group showed larger reductions in lifetime ASCVD risk (−15.9% v −11.0%; difference −4.59%; P<0.001), systolic blood pressure (−23.2 mm Hg v −15.2 mm Hg; difference −7.64 mm Hg; P<0.001), diastolic blood pressure (−10.9 mm Hg v −6.9 mm Hg; difference: −3.59 mm Hg; P<0.001), fasting blood glucose (−0.9 mmol/L v −0.5 mmol/L; difference −0.30 mmol/L; P=0.008), proportion of daily smokers (−3.1% v −0.6%; odds ratio 0.60, 95% CI 0.43 to 0.84; P=0.003), and insufficient physical activity (−3.0% v 1.3%; odds ratio 0.63, 0.42 to 0.95; P=0.03). No significant differences were observed for change in non-high density lipoprotein cholesterol or proportion of participants with obesity.ConclusionsThe village doctor-led mobile health intervention was effective at reducing cardiovascular risk and improving control of behavioural and metabolic risk factors. This feasible approach could be scaled up in rural China and other under-resourced settings to improve health management based on the local primary healthcare system.Trial registrationClinicalTrials.gov NCT05645640.
Journal Article
Properties and Microstructure of Ceramsite Prepared from Xixiayuan Reservoir Sediment
2025
The Sediment problem is the key difficulty in the treatment of the Yellow River. The Sediment in the Yellow River can be used as a substitute for clay and shale soil in the preparation of ceramsite, which is of great significance for the protection of arable land, and mountain areas, and exploring new models of silt resource utilization, meanwhile promoting high-quality regional social development. This article systematically reveals the effects of inorganic foaming agent types, dosages, calcination temperature, and calcination time on the properties and microstructure of ceramsite prepared from the Xixiayuan Reservoir Sediment. The results can provide scientific support for the multi-channel utilization of dredged sediment in the Xixiayuan Reservoir. The study shows that: ① The optimal mix ratio for the preparation of ceramsite from the Xixiayuan Reservoir is 75% sediment, 5% basalt, 10% CaCO 3 , 5% MnO 2 , and 5% sawdust. The optimal calcination temperature is 1110°C, and the calcination time is 10 minutes. ② The main mineral components of ceramsite are quartz, feldspar, calcite, hematite, and magnetite. After heat treatment progresses, the absorption peaks and intensities of functional groups such as CO 3 2− and Si-OH in ceramsite blanks undergo significant changes. ④ The bulk density of ceramsite is 833 kg/m 3 . The barrel pressure strength is 13.55 MPa. The water absorption rate is 3.90%. The softening coefficient is 0.98. The mass loss rate after 15 freeze-thaw cycles is 1.08%, and the boiling loss amount is 0.08%. It belongs to the GB 900 density level lightweight and high-strength ceramsite, which can be used in construction as structural concrete or high-strength concrete with load-bearing functions.
Journal Article
The impact of customer knowledge and marketing dynamic capability on innovation performance: an empirical analysis
by
Zhang, Jiemei
,
Falasca, Mauro
,
Li, Like
in
Competitive advantage
,
Customer services
,
Entrepreneurs
2017
Purpose
This paper aims to explore the intermediary role of marketing dynamic capability (MDC) in the relationship between customer knowledge management (CKM) and product innovation performance (PIP).
Design/methodology
A conceptual model is proposed and a survey instrument is developed. The model is tested empirically in an organizational buyer/seller setting using a survey among middle and top management of firms engaged in business-to-business relationships within high-tech industries in China.
Findings
Results show that MDC fully mediates the relationship between CKM and PIP. Empirical findings thus demonstrate that CKM is related to improved firm PIP through the deployment of firm-specific MDCs.
Research implications/limitations
The study provides clarification for a unique distinction between organizational learning and dynamic capabilities. Findings suggest that knowledge creation occurs within the scope of CKM, while the analytical and perceptual processes that lead to insights and redeployment of firm resources fall under the umbrella of MDCs.
Practical implications
Dynamic capabilities play an essential role in transforming the firm’s knowledge resources to create new configurations in response to market needs. Hence, this study reinforces the role of marketing decision-makers with appropriate decision-making power who, in an ongoing cooperation with other functional areas, are able to adapt and redeploy resources to reflect environmental changes and implement marketing strategy decisions.
Originality/value
This study contributes to the literature by addressing simultaneously the relationship between CKM, MDC and PIP. Specifically, the study demonstrates the mediating influence of MDCs on the relationship between CKM and firm PIP. The study also clarifies a key distinction between organizational learning and dynamic capabilities, demonstrating that knowledge serves an antecedent role to the deployment of dynamic capabilities.
Journal Article