Non-alcoholic fatty liver disease (NAFLD) is characterized by dysbiosis. The bidirectional effects between intestinal microbiota (IM) and bile acids (BA) suggest that dysbiosis may be accompanied by ...an altered bile acid (BA) homeostasis, which in turn can contribute to the metabolic dysregulation seen in NAFLD. This study sought to examine BA homeostasis in patients with NAFLD and to relate that with IM data.
This was a prospective, cross-sectional study of adults with biopsy-confirmed NAFLD (non-alcoholic fatty liver: NAFL or non-alcoholic steatohepatitis: NASH) and healthy controls (HC). Clinical and laboratory data, stool samples and 7-day food records were collected. Fecal BA profiles, serum markers of BA synthesis 7-alpha-hydroxy-4-cholesten-3-one (C4) and intestinal BA signalling, as well as IM composition were assessed.
53 subjects were included: 25 HC, 12 NAFL and 16 NASH. Levels of total fecal BA, cholic acid (CA), chenodeoxycholic acid (CDCA) and BA synthesis were higher in patients with NASH compared to HC (p<0.05 for all comparisons). The primary to secondary BA ratio was higher in NASH compared to HC (p = 0.004), but ratio of conjugated to unconjugated BAs was not different between the groups. Bacteroidetes and Clostridium leptum counts were decreased in in a subset of 16 patients with NASH compared to 25 HC, after adjusting for body mass index and weight-adjusted calorie intake (p = 0.028 and p = 0.030, respectively). C. leptum was positively correlated with fecal unconjugated lithocholic acid (LCA) (r = 0.526, p = 0.003) and inversely with unconjugated CA (r = -0.669, p<0.0001) and unconjugated CDCA (r = - 0.630, p<0.0001). FGF19 levels were not different between the groups (p = 0.114).
In adults with NAFLD, dysbiosis is associated with altered BA homeostasis, which renders them at increased risk of hepatic injury.
Decision making requires an actor to not only steer behavior toward specific goals but also determine the optimal vigor of performance. Current research and models have largely focused on the former ...problem of how actions are directed while overlooking the latter problem of how they are energized. Here we designed a self-paced decision-making paradigm, which showed that rats' performance vigor globally fluctuates with the net value of their options, suggesting that they maintain long-term estimates of the value of their current state. Lesions of the dorsomedial striatum (DMS) and, to a lesser degree, in the ventral striatum impaired such state-dependent modulation of vigor, rendering vigor to depend more exclusively on the outcomes of immediately preceding trials. The lesions, however, spared choice biases. Neuronal recordings showed that the DMS is enriched in net value-coding neurons. In sum, the DMS encodes one's net expected return, which drives the general motivation to perform.
Due to the flexible motion characteristics, helical milling could achieve high surface quality and cutting stability. The effects of input parameters on specific cutting energy (SCE) during the ...medium density fiberboard (MDF) helical up-milling process were studied. Results of analysis of variance showed that the helical angle and depth of milling had extremely significant effects on SCE. SCE increased with increased helical angle, but decreased with increased milling depth. The impact of the rotation speed of the main shaft was non-significant. Due to the highest R
2
value, a quadratic model was selected to establish the relationship between input parameters and SCE. The relative errors between predicting results and confirmatory test results were minimal, which meant that the model had high predicting accuracy. Under the selected input parameters, the optimized parameters were 54°, 5500 r/min, 1.5 mm for helical angle, the rotation speed of the main shaft, depth of milling, respectively. Although the arithmetic average of absolute roughness (Ra) and mean peak-to-valley height (Rz) increased about 58.3% and 46.2%, respectively, under the optimal milling parameters, the optimization was feasible at the initial rough machining stage. These results will be beneficial in guiding the selection of processing parameters to achieve reducing SCE.
The cutting power consumption of milling has direct influence on the economic benefits of manufacturing particle boards. The influence of the milling parameters on the cutting power were investigated ...in this study. Experiments and data analyses were conducted based on the response surface methodology. The results show that the input parameters had significant effects on the cutting power. The high rake angle reduced the cutting force. Thus, the cutting power decreased with the increase in the rake angle and the cutting energy consumption was also reduced. The cutting power increased with the rotation speed of the main shaft and the depth of milling induced the impact resistance between the milling tool and particle board and the material removal rate. The
-values of the created models and input parameters were less than 0.05, which meant they were significant for cutting power and power efficiency. The depth of milling was the most important factor, followed by the rotation speed of the main shaft and then the rake angle. Due to the high values of R
of 0.9926 and 0.9946, the quadratic models were chosen for creating the relationship between the input parameters and response parameters. The predicted values of cutting power and power efficiency were close to the actual values, which meant the models could perform good predictions. To minimize the cutting power and maximize the power efficiency for the particle board, the optimized parameters obtained via the response surface methodology were 2°, 6991.7 rpm, 1.36 mm for rake angle, rotation speed of the main shaft and depth of milling, respectively. The model further predicted that the optimized parameters combination would achieve cutting power and power efficiency values of 52.4 W and 11.9%, respectively, with the desirability of 0.732. In this study, the influence of the input parameters on the cutting power and power efficiency are revealed and the created models were useful for selecting the milling parameters for particle boards, to reduce the cutting power.
Preeclampsia, a systemic syndrome of pregnancy clinically characterized by new onset of proteinuria and hypertension, is associated with significant morbidity and mortality to both mothers and ...fetuses. The pathogenesis of preeclampsia has been enigmatic; this review will focus on understanding the origins of this disorder. Preeclampsia originates in the placenta, starting with inadequate cytotrophoblast invasion and ending with widespread maternal endothelial dysfunction. Production of placental anti-angiogenic factors, specifically soluble fms-related tyrosine kinase 1 and soluble endoglin, have been shown to be upregulated in preeclampsia. These placental anti-angiogenic factors are released into the maternal circulation; their actions disrupt the maternal endothelium and result in hypertension, proteinuria, and the other systemic manifestations of preeclampsia. The molecular basis for placental dysregulation of these pathogenic factors remains unknown, remains unknown. Hypoxia is likely an important regulator. Other factors such as alterations in the renin-angiotensin-aldosterone axis, immune maladaption, excessive shedding of trophoblast debris, oxidative stress, and genetic factors likely contribute to the pathogenesis of the abnormal placentation. As of 2009, the only successful treatment for preeclampsia is delivery. No definitive preventive strategies have been identified. However, several of the recent observations related to phenotypic causality provide stimuli for the development of novel therapies.
Selenium (Se) is an essential micronutrient for humans, acting as a component of the unusual amino acids, selenocysteine (Se-Cys) and selenomethionine (Se-Met). Where Se levels are low, the cell ...cannot synthesise selenoproteins, although some selenoproteins and some tissues are prioritised over others. Characterised functions of known selenoproteins, include selenium transport (selenoprotein P), antioxidant/redox properties (glutathione peroxidases (GPxs), thioredoxin reductases and selenoprotein P) and anti-inflammatory properties (selenoprotein S and GPx4). Various forms of Se are consumed as part of a normal diet, or as a dietary supplement. Supplementation of tissue culture media, animal or human diets with moderate levels of certain Se compounds may protect against the formation of DNA adducts, DNA or chromosome breakage, and chromosome gain or loss. Protective effects have also been shown on mitochondrial DNA, and on telomere length and function. Some of the effects of Se compounds on gene expression may relate to modulation of DNA methylation or inhibition of histone deacetylation. Despite a large number of positive effects of selenium and selenoproteins in various model systems, there have now been some human clinical trials that have shown adverse effects of Se supplementation, according to various endpoints. Too much Se is as harmful as too little, with animal models showing a "U"-shaped efficacy curve. Current recommended daily allowances differ among countries, but are generally based on the amount of Se necessary to saturate GPx enzymes. However, increasing evidence suggests that other enzymes may be more important than GPx for Se action, that optimal levels may depend upon the form of Se being ingested, and vary according to genotype. New paradigms, possibly involving nutrigenomic tools, will be necessary to optimise the forms and levels of Se desirable for maximum protection of genomic stability in all humans.
Data from The Society of Thoracic Surgeons Adult Cardiac Surgery Database were analyzed to identify trends in patient characteristics and outcomes of mitral valve operations in North America.
All ...patients with isolated primary mitral valve operations with or without tricuspid valve repair, surgical atrial fibrillation ablation, or atrial septal defect closure performed July 2011 to September 2016 were identified. A subgroup analysis assessed patients with degenerative leaflet prolapse (DLP).
Isolated primary mitral valve operations were performed on 87,214 patients at 1,125 centers, increasing by 24% between 2011 (n = 14,442) and 2016 (n = 17,907). The most common etiology was DLP (60.7%); 4.3% had functional mitral regurgitation. Preoperatively, 47.3% of patients had an ejection fraction less than 60% and 34.2% had atrial fibrillation. Overall mitral valve repair rate was 65.6%, declining from 67.1% (2011) to 63.2% (2016; p < 0.0001). Repair rates were related to etiology (DLP, 82.5%; rheumatic, 17.5%). Of the 29,970 mitral valve replacements, 16.2% were preceded by an attempted repair. Repair techniques included prosthetic annuloplasty (94.3%), leaflet resection (46.5%), and artificial cord implantation (22.7%). Bioprosthetic valves were implanted with increasing frequency (2011, 65.4%; 2016, 75.8%; p < 0.0001). Less-invasive operations were performed in 23.0% and concomitant tricuspid valve repair in 15.7%. Unadjusted operative mortality was 3.7% (replacements) and 1.1% (repairs).
Patients undergoing primary isolated mitral valve operations commonly have ventricular dysfunction, atrial fibrillation, and heart failure. Although contemporary outcomes are excellent, earlier guideline-directed referral and increased frequency and quality of repair may further improve results of mitral valve operations.
Aluminum phosphate (AP) shows great potential to replace formaldehyde-based adhesives in the wood industry, except for its weak hygroscopic resistance and low wet bonding strength. This study chose ...PVA as an AP modifier to prepare a PVA-AP organic-inorganic hybrid adhesive (PAP). The preparation, bonding mechanism and heat resistant property of PAP were studied by using X-ray photoelectron spectroscopy (XPS), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC), nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). The result showed that covalent bonds between PVA and AP were built. The mechanical properties of PAP improved remarkably; the dry and wet bonding strength are 2.28 and 0.79 MPa with 15.2% and 690% increment, respectively, compared to the control samples. The thermostabilities of PAP and plywood samples were improved. In conclusion, PVA could effectively improve the hygroscopic resistance and low wet bonding strength of AP adhesives.
Eco-benign PVA/aluminum phosphate (PAP) shows great potential to replace formaldehyde-based adhesives in the wood industry, owing to the effectively improvement of hygroscopic resistance and wet bonding strength.
To adopt a greener approach, a novel thermal treatment for wood was proposed. Poplar wood surface was treated by CO2 laser and the surface color changes were evaluated by CIELAB color space. The ...treated and untreated surface were scanned by Epson scanner to measure lightness difference (ΔL*), red-green index difference (Δa*) and yellow-blue index difference (Δb*), then the total color difference (ΔE*) was calculated. The laser energy load on wood surface caused characteristic changes in the chemical component, which were determined by means of Fourier infrared spectrometer (FTIR). Response surface methodology (RSM) was used for modelling and to establish a relationship between color changes and laser modification parameters. The results showed that the feed speed, sweep width and laser power had significant effects on color changes of wood surface. The ΔE* increased with the increasing of laser power, however it decreased with increasing of feed speed and sweep width, because of the amount of heat transferring decreased with the increasing of feed speed and sweep width. The results of FTIR revealed chemical structure in the wood components, which is one of the reasons to the color changes of the wood surfaces. The established quadratic mathematical model applied to describe the relationship between color changes and laser modification parameters had a good prediction. It will be useful for selecting appropriate modification parameters to achieve desired color changes.
Abstract
The hysteretic behavior of bolt connections in a timber–concrete composite (TCC) bridge was investigated. Six identical TCC specimens were designed with bolted connections and subjected to ...reversed cyclic loading tests. The failure modes, energy dissipation capacity, stiffness degradation, strength degradation, and hysteretic responses of the specimens were evaluated. The experimental results indicate that the predominant failure mode was a dual-hinge mechanism in the bolts of the TCC specimens. The TCC specimens exhibited satisfactory energy dissipation and achieved a mean ductility factor of 6.76. A finite-element model was developed to simulate the cyclic response of the tested TCC specimens. The simulated data are in good agreement with the experimental data. The experimental and numerical results reported are useful for the development of design guidelines for TCC bridges with bolted connections.
PDF
