Abstract
Infected bone defects are a major challenge in orthopedic treatment. Native bone tissue possesses an endogenous electroactive interface that induces stem cell differentiation and inhibits ...bacterial adhesion and activity. However, traditional bone substitutes have difficulty in reconstructing the electrical environment of bone. In this study, we develop a self-promoted electroactive mineralized scaffold (sp-EMS) that generates weak currents via spontaneous electrochemical reactions to activate voltage-gated Ca
2+
channels, enhance adenosine triphosphate-induced actin remodeling, and ultimately achieve osteogenic differentiation of mesenchymal stem cells by activating the BMP2/Smad5 pathway. Furthermore, we show that the electroactive interface provided by the sp-EMS inhibits bacterial adhesion and activity via electrochemical products and concomitantly generated reactive oxygen species. We find that the osteogenic and antibacterial dual functions of the sp-EMS depend on its self-promoting electrical stimulation. We demonstrate that in vivo, the sp-EMS achieves complete or nearly complete in situ infected bone healing, from a rat calvarial defect model with single bacterial infection, to a rabbit open alveolar bone defect model and a beagle dog vertical bone defect model with the complex oral bacterial microenvironment. This translational study demonstrates that the electroactive bone graft presents a promising therapeutic platform for complex defect repair.
Using a submerged pipeline section modeling the touchdown zone (TDZ) of a steel catenary riser (SCR), a sequence of contrast experiments were carried out to investigate the influences of seabed ...stiffness and water damping. Acceleration signals and bending strains at discrete positions along the TDZ pipe model were recorded during the testing, and by dealing with response-only data using the frequency domain decomposition method (FDDM) the results characterizing TDZ dynamic behaviors were acquired. These results indicate that under the excitation from the seabed model the complex modal responses appear with much higher frequencies than the end-loading one, similar to the dynamic response of a SCR TDZ, whose practical vibration frequencies are much higher than the heave motion of a hull. Identifications of complex modal parameters have proven to be effective using experimental response data, and this identification process can be applied in SCR TDZ monitoring to investigate seabed stiffness influences and water damping effects.
•Scaled SCR TDZ monitoring simulation tests are carried out in a flume and bending strain data and acceleration signals are recorded.•Different seabed stiffnesses and water damping conditions are simulated to acquire comparable test results.•The feasibility of FDDM had been verified for TDZ modal identification from response-only data.•SCR TDZ vibration is a high-frequency complex modal response when the seabed stiffness has an important influence.
Conductivity is a very reliable, sensitive, and easily obtained indicator of surface water conditions; however, whether it could be used to evaluate lake pollution is less understood. To verify the ...effectiveness of using conductivity to evaluate the pollution status in lakes, Lake Taihu was analyzed, the third largest freshwater lake in China, which provides drinking water to about 10 million of residents. We analyzed 25-year conductivity data in 32 sampling sites in Lake Taihu, in relation to human population, industrial development, and GDP. The results showed that the conductivity first increased and then decreased following rapid economic growth and subsequent strict pollution control activities. The conductivity is related to industrial sewage (
r
= 0.90); SO
4
2−
and Cl
−
concentrations in the water were closely related to the industrial production value (
r
= 0.98, 0.99) before 2007. The conductivity increased rapidly from 1992 to 2007 due to eutrophication processes. After 2007, with the implementation of various pollution control measures, the pollution situation gradually abated. The conductivity was closely related to the concentrations of nitrogen and phosphorus (
r
= 0.53, 0.14) in Lake Taihu, which suggests that conductivity could be indicator of eutrophication in lakes to some extent. Based on the research results, conductivity can largely be used to characterize the impact of human activities on lakes. Our study suggests that conductivity is a very reliable parameter for evaluating lake pollution. In addition to providing ion information, this measurement could successfully determine pollution sources and restoration effectiveness in lakes, such as ecologically complex Lake Taihu.
Realization of the Kagome antiferromagnetic (KAF) lattice is of high interest because the geometric frustration in the Kagome lattice is expected to give rise to highly degenerated ground states that ...may host exotic phases such as quantum spin liquid. Here we demonstrate the design and synthesis of a single-layer two-dimensional metal–organic framework (2D-MOF) containing a Kagome lattice of Fe(II) ions assembled on a Au(111) surface. First-principles calculations reveal that the Fe(II) ions are at a high spin state of S = 2 and are coupled antiferromagnetically with nearest-neighboring exchange J 1 = 5.8 meV. The ground state comprises various degenerated spin configurations including the well-known q = 0 and q = √3 × √3 phases. Remarkably, we observe a spin excitation at 6 meV using tunneling spectroscopy. This work points out a feasible route toward realizing spin 1/2 KAF, a candidate quantum spin liquid system, by replacing Fe(II) by Cu(II) in the same structure.
All birds reproduce via internal fertilization, but only ~3% of male birds possess the external genitalia that allows for intromission. Waterfowl (e.g., duck and goose) are representatives of them, ...and the external genitalia development of male geese is directly related to mating ability. Notably, some male geese show abnormal external genitalia development during ontogenesis. However, until now little is known about the molecular mechanisms of the external genitalia development in goose. In the present study, comparative transcriptomic analyses were performed on the hypothalamus, pituitary gland, testis, and external genitalia isolated from the 245-day-old male Tianfu meat geese showing normal (NEGG, n = 3) and abnormal (AEGG, n = 3) external genitals in order to provide a better understanding of the mechanisms controlling the development of the external genitalia in aquatic bird species.
There were 107, 284, 2192, and 1005 differentially expressed genes (DEGs) identified in the hypothalamus, pituitary gland, testis and external genitalia between NEGG and AEGG. Functional enrichment analysis indicated that the DEGs identified in the hypothalamus were mainly enriched in the ECM-receptor interaction pathway. The ECM-receptor interaction, focal adhesion, and neuroactive ligand-receptor interaction pathways were significantly enriched by the DEGs in the pituitary gland. In the testis, the DEGs were enriched in the neuroactive ligand-receptor interaction, cell cycle, oocyte meiosis, and purine metabolism. In the external genitalia, the DEGs were enriched in the metabolic, neuroactive ligand-receptor interaction, and WNT signaling pathways. Furthermore, through integrated analysis of protein-protein interaction (PPI) network and co-expression network, fifteen genes involved in the neuroactive ligand-receptor interaction and WNT signaling pathways were identified, including KNG1, LPAR2, LPAR3, NPY, PLCB1, AVPR1B, GHSR, GRM3, HTR5A, FSHB, FSHR, WNT11, WNT5A, WIF1, and WNT7B, which could play crucial roles in the development of goose external genitalia.
This study is the first systematically comparing the hypothalamus, pituitary gland, testis, and external genitalia transcriptomes of male geese exhibiting normal and abnormal external genitals. Both bioinformatic analysis and validation experiments indicated that the neuroactive ligand-receptor interaction pathway could regulate the WNT signaling pathway through PLCB1 to control male goose external genitalia development.
Many aquatic ecosystems are seriously threatened by cyanobacteria blooms; gas vesicles enable cyanobacteria to form harmful cyanobacterial blooms rapidly. Many lake managers try to control ...cyanobacterial blooms by collapsing gas vesicle, but it is still unclear whether gas vesicle recovery will cause this method to fail. Through the culture experiments of three cyanobacteria, it was found that all cyanobacteria with collapsed gas vesicles can rapidly regain buoyancy in a few days under nutrient-sufficient environments, and average gas vesicle content was even 9% higher than initially. In contrast, buoyancy recovery of all cyanobacteria under nutrient-limited environments was significantly worse. After culture experiments, the average gas vesicle content of all cyanobacteria in phosphorus-limited environments only reach 49% of the initial value. The gas vesicle content of two non-nitrogen-fixing cyanobacteria in nitrogen-limited environments only reached 38% of initial value. The buoyancy of cyanobacteria in different tropic levels was similar to the gas vesicle content. These results indicate that collapsing gas vesicles can only control cyanobacterial blooms in the short-term. To control cyanobacterial blooms in the long-term, in deep lakes, lake managers should discharge gas vesicles’ collapsed cyanobacteria into deep water. In shallow lakes, the disruption of gas vesicles must be combined with nutrient control measures to effectively control cyanobacteria blooms.
The aim of this study is to develop a tool to measure health literacy and attitude towards melanoma and to assess the tool in a group of adolescents through a multicenter cross-sectional survey. The ...concept, dimensionality, and item pool of the tool were developed by a focus group. The Delphi method was applied to determine the content validity. Newly enrolled students in five universities were invited to an online questionnaire survey. Items were selected according to correlation, factor loading, and item response parameters. Psychometric properties (reliability, construct validity, and measurement invariance) were assessed using McDonald’s
ω
and confirmatory factor analysis (CFA), respectively. A total of 21,086 valid questionnaires were collected. The focus group drafted two subscales and 13 items. Content validity was good for all items (Kappa > 0.7). One item was removed from the tool owing to low factor loading and discrimination parameter. McDonald’s
ω
of the subscales were 0.84 (health literacy) and 0.86 (attitude). Local dependencies were identified in CFA; after modification, the goodness-of-fit was satisfactory (comparative fit index, CFI > 0.98). The tool showed measurement invariance across subgroups of gender, ethnicity, and university (CFI change < 0.01 across models). The brief tool to measure health literacy and attitude towards nevus and melanoma shows good psychometric properties and measurement invariance. It can be used in further investigation.
•Exposure to NO2, NOX and PM2.5 may increase the risk of dementia onset.•Low levels of physical activity, poor sleep patterns, and smoking are associated with an elevated risk of dementia.•NO2, NOX, ...or PM2.5 exposure and low levels of physical activity, poor sleep patterns or smoking have a joint effect on dementia.•Moderate to high levels of physical activity could attenuate the incident risk of Alzheimer’s disease caused by air pollution.
Dementia is an important disease burden among the elderly, and its occurrence may be profoundly affected by environmental factors. Evidence of the relationship between air pollution and dementia is emerging, but the extent to which this can be offset by lifestyle factors remains ambiguous.
This study comprised 155,828 elder adults aged 60 years and above in the UK Biobank who were dementia-free at baseline. Cox proportional hazard models were conducted to examine the associations of annual average levels of air pollutants in 2010, including nitrogen dioxide (NO2), nitrogen oxides (NOX), particulate matter (PM2.5, PM10, and PMcoarse) and lifestyle factors recorded at baseline physical activity (PA), sleep patterns, or smoking status with incident risk of dementia, and their interactions on both multiplicative and additive scales.
During a 12-year period of follow-up, 4,389 incidents of all-cause dementia were identified. For each standarddeviationincrease in ambient NO2, NOX or PM2.5, all-cause dementia risk increases by 1.07-fold hazard ratio (HR) and 95 % confidence interval (CI) = 1.07 (1.04, 1.10), 1.05-fold (95 % CI: 1.02, 1.08) and 1.07-fold (95 % CI: 1.04, 1.10), whereas low levels of PA, poor sleep patterns, and smoking are associated with an elevated risk of dementia HR (95 % CI) = 1.17 (1.09, 1.26), 1.13 (1.00, 1.27), and 1.14 (1.07, 1.21), respectively. Furthermore, these air pollutants show joint effects with low PA, poor sleep patterns, and smoking on the onset of dementia. The moderate to high levels of PA could significantly or marginally significantly modify the associations between NO2, NOX or PM2.5 (P-int = 0.067, 0.036, and 0.067, respectively) and Alzheimer’s disease (AD), but no significant modification effects are found for sleep patterns or smoking status.
The increased exposures of NO2, NOX, or PM2.5 are associated with elevated risk of dementia among elderly UK Biobank population. These air pollutants take joint effects with low PA, poor sleep patterns, and smoking on the development of dementia. In addition, moderate to high levels of PA could attenuate the incident risk of AD caused by air pollution. Further prospective researches among other cohort populations are warranted to validate these findings.
Abstract
This study was to develop a computer vision evaluation method to automatically measure the degree of scoliosis based on the machine learning algorithm. For the X-ray images of 204 patients ...with idiopathic scoliosis who underwent full-spine radiography, histogram equalization of original image was performed before a flipping method was used to magnify asymmetric elements, search for the global maximum pixel value in each line, and scan local maximal pixel value, with the intersection set of two point sets being regarded as candidate anchor points. All fine anchors were fitted with cubic spline algorithm to obtain the approximate curve of the spine, and the degree of scoliosis was measured by the standardized integral area. All measured data were analyzed. In manual measurement, the Cobb angle was 11.70–25.00 (20.15 ± 3.60), 25.20–44.70 (33.89 ± 5.41), and 45.10–49.40 (46.98 ± 1.25) in the mild, moderate and severe scoliosis group, respectively, whereas the value for the standardized integral area algorithm was 0.072–0.298 (0.185 ± 0.040), 0.100–0.399 (0.245 ± 0.050), and 0.246–0.901 (0.349 ± 0.181) in the mild, moderate and severe scoliosis group, respectively. Correlation analysis between the manual measurement of the Cobb angle and the evaluation of the standardized integral area algorithm demonstrated the Spearman correlation coefficient r = 0.643 (
P
< 0.001). There was a positive correlation between the manual measurement of the Cobb angle and the measurement of the standardized integral area value. Two methods had good consistency in evaluating the degree of scoliosis. ROC curve analysis of the standardized integral area algorithm to measure the degree of scoliosis showed he cutoff value of the standardized integral area algorithm was 0.20 for the moderate scoliosis with an AUC of 0.865, sensitivity 0.907, specificity 0.635, accuracy 0.779, positive prediction value 0.737 and negative prediction value 0.859, and the cutoff value of the standardized integral area algorithm was 0.40 for the severe scoliosis with an AUC of 0.873, sensitivity 0.188, specificity 1.00, accuracy 0.936, positive prediction value 1 and a negative prediction value 0.935. Using the standardized integral area as an independent variable and the Cobb angle as a dependent variable, a linear regression equation was established as Cobb angle = 13.36 + 70.54 × Standardized area, the model has statistical significance. In conclusion,
t
he integrated area algorithm method of machine learning can quickly and efficiently assess the degree of scoliosis and is suitable for screening the degree of scoliosis in a large dataset as a useful supplement to the fine measurement of scoliosis Cobb angle.
