China’s urbanization has attracted many scholars’ attention due to its significant impact on socioeconomic sustainability. Many studies have explored the spatial pattern and effects of the factors ...influencing urban expansion. However, the spatiotemporal dynamics integrating spatial and temporal dimensions and the spatial scales of the influencing factors are always ignored. This study applied the framework of exploratory space–time data analysis (ESTDA) to investigate the spatiotemporal dynamics of urban expansion across 342 cities in China from 1990 to 2017 and, further, used multiscale geographically weighted regression (MGWR) to estimate the effects of influencing factors on urban expansion. We found that urban expansion had an obvious south–north division, and yet the effects of influencing factors usually showed an east–west division. We also found that the dynamic local spatial dependency of urban expansion was accompanied by a volatile coevolution process and inclined to transfer from heterogeneity to homogeneity, and homogeneity tended to be stable. The coevolution of urban expansion between cities and other neighboring ones became stronger with increases in time and regional integration. These findings support the use of customized urban planning for specific regions in different spatial dependence to improve land-use efficiency and coordinate regional development.
Polyhexamethylene biguanide (PHMB) is a broad-spectrum antiseptic which avoids many efficacy and toxicity problems associated with antimicrobials, in particular, it has a low risk of loss of ...susceptibility due to acquired antimicrobial resistance. Despite such advantages, PHMB is not widely used in wound care, suggesting more research is required to take full advantage of PHMB's properties. We hypothesised that a nanofibre morphology would provide a gradual release of PHMB, prolonging the antimicrobial effects within the therapeutic window. PHMB:polyurethane (PU) electrospun nanofibre membranes were prepared with increasing PHMB concentrations, and the effects on antimicrobial activities, mechanical properties and host cell toxicity were compared. Overall, PHMB:PU membranes displayed a burst release of PHMB during the first hour following PBS immersion (50.5-95.9% of total released), followed by a gradual release over 120 h (≤25 wt % PHMB). The membranes were hydrophilic (83.7-53.3°), gradually gaining hydrophobicity as PHMB was released. They displayed superior antimicrobial activity, which extended past the initial release period, retained PU hyperelasticity regardless of PHMB concentration (collective tensile modulus of 5-35% PHMB:PU membranes, 3.56 ± 0.97 MPa; ultimate strain, >200%) and displayed minimal human cell toxicity (<25 wt % PHMB). With further development, PHMB:PU electrospun membranes may provide improved wound dressings.
In this work, poly(vinyl pyrrolidone) (PVP) wrapped multi-walled carbon nanotube (MWCNT) reinforced poly(vinyl alcohol) (PVA) composite hydrogel was investigated. The addition of PVP was proved to ...facilitate uniform distribution of nanotubes and improve the interface between nanotubes and matrix. The tensile strength, modulus, toughness, tear strength and friction coefficient of MWCNT–PVP/PVA composite hydrogels with different MWCNT contents were measured and compared. The results demonstrated that the mechanical properties of the composite hydrogel were improved significantly by adding less than 2
wt% of PVP treated MWCNTs, and the increase of mechanical properties depended on the concentration and distribution of the nanotubes. The friction coefficient of the composite hydrogel was decreased essentially due to the lubrication effect of PVP and independent of MWCNT concentration. The overall performance of the composites manifested that PVP as a nonionic surfactant played a synergistic role with MWCNTs in the production and performance of PVA composite hydrogels.
Sustained release of copper (Cu) ions from Cu-containing intrauterine devices (CuIUD) is quite efficient for contraception. However, the tissue surrounding the CuIUD is exposed to toxic Cu ion ...levels. The objective for this study was to quantify the concentration dependent cytotoxic effects of Cu ions and correlate the toxicity due to Cu ion burst release for two popular T-shaped IUDs - TCu380A and TCu220C on L929 mouse fibroblasts. Fibroblasts were cultured in 98 well tissue culture plates and 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphehyltetrazolium bromide (MTT) assay was used to determine their viability and proliferation as a function of time. For cell seeding numbers ranging from 10,000 to 100,000, a maximum culture time of 48 h was identified for fibroblasts without significant reduction in cell proliferation due to contact inhibition. Thus, for Cu cytotoxicity assays, a cell seeding density of 50,000 and a maximum culture time of 48 h in 96 well plates were used. 24 h after cell seeding, culture media were replaced with Cu ion containing media solutions of different concentrations, including 24 and 72 h extracts from TCuIUDs and incubated for a further 24 h. Cell viability decreased with increasing Cu ion concentration, with 30 % and 100 % reduction for 40 μg/ml and 100 μg/ml respectively at 24 h. The cytotoxic effects were further evaluated using light microscopy, apoptosis and cell cycle analysis assays. Fibroblasts became rounded and eventually detached from TCP surface due to Cu ion toxicity. A linear increase in apoptotic cell population with increasing Cu ion concentration was observed in the tested range of 0 to 50 μg/ml. Cell cycle analysis indicated the arrest of cell division for the tested 25 to 50 μg/ml Cu ion treatments. Among the TCuIUDs, TCu220C having 265 mm
2
Cu surface area released 9.08 ± 0.16 and 26.02 ± 0.25 μg/ml, while TCu380A having 400 mm
2
released 96.7 ± 0.11 and 159.3 ± 0.15 μg/ml respectively following 24 and 72 h extractions. The effects of TCuIUD extracts on viability, morphology, apoptosis and cell cycle assay on L929 mouse fibroblasts cells, were appropriate for their respective Cu ion concentrations. Thus, a concentration of about 46 μg/ml (~29 μM) was identified as the LD50 dose for L929 mouse fibroblasts when exposed for 24 h based on our MTT cell viability assay. The burst release of lethal concentration of Cu ions from TCu380A, especially at the implant site, is a cause of concern, and it is advisable to use TCuIUD designs that release Cu ions within cytotoxic limits yet therapeutic, similar to TCu220C.
The aim of this study was to develop polyurethane (PU) based fibro-porous membranes and to investigate the size-effect of hierarchical porous structure on permeability and surface properties of the ...developed electrospun membranes. Non-woven Selectophore™ PU membranes having tailored fibre diameters, pore sizes, and thickness were spun using electrospinning, and their chemical, physical and glucose permeability properties were characterised. Solvents, solution concentration, applied voltage, flow rate and distance to collector, each were systematically investigated, and electrospinning conditions for tailoring fibre diameters were identified. Membranes having average fibre diameters—347, 738 and 1102nm were characterized, revealing average pore sizes of 800, 870 and 1060nm and pore volumes of 44%, 63% and 68% respectively. Hydrophobicity increased with increasing fibre diameter and porosity. Effective diffusion coefficients for glucose transport across the electrospun membranes varied as a function of thickness and porosity, indicating high flux rates for mass transport. Electrospun PU membranes having significantly high pore volumes, extensively interconnected porosity and tailorable properties compared to conventional solvent cast membranes can find applications as coatings for sensors requiring analyte exchange.
► Precise control of fibre diameter and porous structure of electrospun biomedical PU membrane. ► The size-effect of hierarchical porous structure on permeability and surface properties of electrospun PU membranes. ► PU membranes with tailored glucose diffusion coefficient provide a mass transport limiting function for biosensors.
End-stage renal disease (ESRD) patients have a high potential cardiovascular burden, and cardiovascular disease (CVD) is the leading cause of death in maintenance haemodialysis (MHD) patients. ...Arteriovenous fistula (AVF) is the preferred vascular access for MHD patients, but AVF significantly affects the haemodynamics of the cardiovascular system, leading to or exacerbating CVD, including atrial fibrillation (AF). This study aimed to evaluate the impact of AVF on cardiac function, especially of the left atrium (LA), in patients with ESRD and to further explore the relationship between AVF establishment and the occurrence of AF.
We selected 1,107 ESRD patients on haemodialysis using AVF and 550 patients with tunneled-cuffed catheters (TCC) admitted between January 2016 and December 2022 for follow-up to compare the rate of AF between the two groups. A total of 153 patients in the AVF group with complete information (clinical data, echocardiographic and biochemical indices, and other data) were enrolled and retrospectively analysed for risk factors for the development of AF and were followed up for adverse clinical outcomes (including all-cause death, cardiac death, readmission due to heart failure, and stroke).
The incidence of new-onset AF was higher in the AVF group than the TCC group after dialysis access was established (16.30% vs. 5.08%,
< 0.001). Echocardiography showed that the LA anteroposterior diameter increased (
< 0.001) and the incidence of AF increased from 11.76% to 26.14% (
= 0.001) after AVF establishment. Multivariate logistic regression analysis showed that age and LA enlargement were independent risk factors for new-onset AF after AVF establishment (
< 0.05). Adverse clinical outcomes were more common in patients with AF than in patients without AF (
< 0.001). Multivariate Cox risk regression analysis suggested that new-onset AF (HR = 4.08, 95% CI: 2.00-8.34,
< 0.001) and left ventricular systolic dysfunction (HR = 2.42, 95% CI: 1.20-4.88,
= 0.01) after AVF establishment were independent risk factors for adverse clinical outcomes.
LA enlargement after AVF establishment is associated with a significant increase in the incidence of AF, in addition, AF which is as an important influential factor in patients with MHD combined other systemic diseases might increase adverse clinical events.
(NCT06199609).
Background To determine the association between lipid metabolism and intrahepatic cholestasis of pregnancy (ICP), and explore the value of maternal alanine aminotransferase/aspartate aminotransferase ...(ALT/AST) and high-density lipoprotein (HDL) in predicting adverse neonatal outcomes in women with ICP. Methods A total of 147 pregnant women with ICP admitted to The Fourth Hospital of Shijiazhuang and 120 normal pregnant women in the same period were selected in this study. The Mann-Whitney U test and Chi-square tests were used to compare the differences in clinical data. Multivariate logistic regression was used to analyze the relationship between ALT/AST and the occurrence of adverse pregnancy outcomes in patients with ICP. The combined predictive value of ALT/AST and HDL was determined by receiver operating characteristic (ROC) curve analysis. Results Among 147 women with ICP, 122 women had total bile acid (TBA) levels of 10–39.9 µmol/L, and 25 had TBA ≥ 40 µmol/L. There was significantly lower gestational age in patients with severe ICP than in those with mild and control groups (all p < 0.05), and the weight of newborns in the maternal ICP group was significantly lower than in the control group ( p < 0.05). Increasing TBA levels was associated with higher AST, ALT, ALT/AST, and lower HDL level (all p < 0.05). Meanwhile, higher levels of ALT/AST was positively associated with neonatal hyperbilirubinemia adjusted odds ratio (AOR) = 4.019, 95% CI 1.757–9.194, p = 0.001 and cardiac injury AOR = 3.500, 95% CI 1.535–7.987, p = 0.003. HDL was a significant protective factor for neonatal hyperbilirubinemia and cardiac injury AOR = 0.315, 95% CI 0.126–0.788, p = 0.014; AOR = 0.134 (0.039–0.461), p = 0.001. The area under the ROC curve (AUC) for prediction of neonatal hyperbilirubinemia by ALT/AST combined with HDL was 0.668 95% CI 56.3–77.3%, p = 0.002, and the sensitivity and specificity were 47.1% and 84.0%, respectively. To predict neonatal cardiac injury, the AUC value was 0.668 95% CI 56.4–77.1%, p = 0.002, with sensitivity and specificity were 41.2% and 87.1%, respectively. Conclusions The levels of higher ALT/AST and lower HDL were significantly associated with the risk of ICP-related adverse neonatal outcomes. Moreover, ALT/AST combined with HDL has moderate clinical value in predicting the adverse outcomes of neonatal hyperbilirubinemia and cardiac injury.
Objective
Low heart rate variability (HRV), an indicator of autonomic nervous system dysfunction, has been associated with increased all-cause and cardiovascular mortality and incident stroke. ...However, the relationship between HRV and cerebral small vessel disease (CSVD) showed contradictory results. We aimed to examine the relationship of HRV and total burden of CSVD and each of the magnetic resonance imaging (MRI) markers of CSVD.
Methods
We recruited 435 patients who attended our hospital for physical examination between June 2020 and August 2021. All underwent 24-h Holter monitoring and MRI scan. The standard deviation of normal-to-normal intervals (SDNN) was selected as the method for HRV assessment. The presence of severe white matter hyperintensity, lacunes, and >10 enlarged basal ganglia perivascular spaces, and cerebral microbleeds were added for estimating the CSVD score (0–4). Multivariate logistic analyses was performed to assess whether HRV was independently associated with the burden of CSVD and each of the MRI markers of CSVD, with and without stratification by prevalent diabetes.
Results
This study included 435 subjects with a mean age of 64.0 (57.0–70.0) years; 49.4% of the patients were male, and 122 (28.0%) had a history of diabetes. In multivariate analyses, lower SDNN was independently associated with total burden of CSVD and the presence of enlarged perivascular spaces in all subjects. According to diabetes stratification, lower SDNN was independently associated with total burden of CSVD and each MRI markers of CSVD separately only in the diabetic group.
Conclusions
Lower HRV was associated with total burden of CSVD and each MRI markers of CSVD separately among diabetic patients, but not among non-diabetic patients.
This experiment was conducted to study the effects of
Bacillus
preparations on immunity and antioxidant activities in grass carp. A total of 315 grass carp, with similar initial weight (average ...weight of fish 45 g), were randomly divided into three groups with three replicates. The control group was fed the basal diet without
Bacillus
; treatment group 1 was added
Bacillus
preparation no. 1 with 1 × 10
8
cfu/m
3
per 7 days in culture water and also fed the basal diet; treatment group 2 was fed the basal diet mixed with 0.5 %
Bacillus
preparation no. 2, and the culture water was added 1 × 10
8
cfu/m
3
Bacillus
preparation no. 1 per 7 days. After 4 weeks of culture, 12 grass carp from each replicate were taken randomly for the determination of immune response and oxidization resistance indices. The results showed that compared with control, the level of globulin and IgM of treatment group 2 was significantly increased (
P
< 0.05), which was also significantly higher (
P
< 0.05) than that of group 1. For the non-specific immunity index, compared with control, the lysozyme activity and complement (C3) content of treatment group 1 significantly increased (
P
< 0.05), and the level of myeloperoxidase and C3 of treatment group 2 was significantly higher (
P
< 0.05) than that of control, which was also significantly higher (
P
< 0.05) than that of group 1. In the serum, compared with the control, the level of total antioxidant activity (T-AOC), antisuperoxide anion free radical (ASAFR) and glutathione (GSH) of two treatment groups was significantly increased (
P
< 0.05); GSH content of treatment group 2 was significantly (
P
< 0.05) higher than that of treatment group 1 and control. There was no significant difference between T-AOC and ASAFR among the two treatment groups; no significant effect was found on glutathione peroxidase (GSH-Px) and maleic dialdehyde (MDA) among the three groups. In the liver, T-AOC, SOD, ASAFR, GSH-Px and GSH from two treatment groups were significantly higher (
P
< 0.05) than those of control; T-AOC, SOD and catalase from treatment group 2 were significantly higher (
P
< 0.05) than those of treatment group 1; and MDA of two treatment groups was significantly decreased (
P
< 0.05) as compared with the control. The results indicate that
Bacillus
preparations added into water can increase serum immunoglobulin levels and most of non-specific immune parameters content and enhance the antioxidant ability of grass carp, while adding
Bacillus
preparation into the water and feed is much better.
Carbon nanotubes show promise for a wide range of applications due to a combination of their unusual structural, mechanical, and electric properties. However, the limited ability to process nanotubes ...hinders the realization of their full potential. To remove this obstacle, research has been focused on the dispersion of nanotubes in solvents through oxidation, grafting, wrapping, and surfactant addition.
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