Search

Farnesoid X receptor (FXR) is an important regulator of glucose and lipid homeostasis. However, the exact role of FXR in diabetes remains to be fully elucidated. The present study examined the effects of chenodeoxycholic acid (CDCA), an agonist of FXR, on metabolism profile in a rat model of type 2 diabetes mellitus (T2DM). Male Wistar rats (8‑week‑old; n=40) were randomized into the following four groups (n=10): Untreated control, CDCA‑treated, T2DM, and CDCA‑treated T2DM. To establish the T2DM model, the rats were fed a high‑fat diet (HFD) for 4 weeks and received a single low‑dose intraperitoneal injection of streptozotocin (30 mg/kg), followed by an additional 4 weeks of HFD feeding. CDCA was administrated (10 mg/kg/d) intraperitoneally for 10 days. Reverse transcription‑quantitative polymerase chain reaction and western blotting assays were performed to determine the RNA and protein expression of FXR, phosphoenolpyruvate carboxykinase, G6Pase, proliferator‑activated receptor‑γ coactivator‑1 and short heterodimer partner in rat liver tissue. The results revealed that FXR activation by CDCA did not reduce body weight, but it lowered the plasma levels of fasting glucose, insulin and triglycerides in the T2DM rats. CDCA administration reversed the downregulation of the mRNA and protein expression of FXR in the T2DM rat liver tissue samples. Furthermore, treatment with CDCA reduced the mRNA and protein expression levels of phosphoenolpyruvate carboxykinase, glucose 6‑phosphatase and peroxisome proliferator‑activated receptor‑γ coactivator‑1 in the liver tissue samples of the T2DM rats. By contrast, CDCA treatment increased the mRNA and protein expression levels of short heterodimer partner in the liver tissue samples of the T2DM rats. In conclusion, FXR agonist treatment induces beneficial effects on metabolism in the rat T2DM model. In conclusion, the present study indicated that the FXR agonist may be useful for the treatment of T2DM and hypertriglyceridemia.

Background: Glaucoma is a progressive optic neuropathy characterized by degeneration of neurons due to loss of retinal ganglion cells (RGCs). High intraocular pressure (HIOP), the main risk factor, causes the optic nerve damage. However, the precise mechanism of HIOP-induced RGC death is not yet completely understood. This study was conducted to determine apoptosis of RGC-5 cells induced by elevated hydrostatic pressures, explore whether laminin is associated with apoptosis under pressure, whether laminin can protect RGCs from apoptosis and affirm the mechanism that regulates the process of RGCs survival. Methods: RGC-5 cells were exposed to 0, 20, 40, and 60 mmHg in a pressurized incubator for 6, 12, and 24 h, respectively. The effect of elevated hydrostatic pressure on RGC-5 cells was measured by Annexin V-fluorescein isothiocyanate/propidium iodide staining, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and Western blotting of cleaved caspase-3 protein. Location and expression of laminin were detected by immunofluorescence. The expression of β1-integrin, phosphorylation of focal adhesion kinase (FAK) and protein kinase B (PKB, or AKT) were investigated with real-time polymerase chain reaction and Western blotting analysis. Results: Elevated hydrostatic pressure induced apoptosis in cultured RGC-5 cells. Pressure with 40 mmHg for 24 h induced a maximum apoptosis. Laminin was declined in RGC-5 cells after exposing to 40 mmHg for 24 h. After pretreating with laminin, RGC-5 cells survived from elevated pressure. Furthermore, β1-integrin and phosphorylation of FAK and AKT were increased compared to 40 mmHg group. Conclusions: The data show apoptosis tendency of RGC-5 cells with elevated hydrostatic pressure. Laminin can protect RGC-5 cells against high pressure via β1-integrin/FAK/AKT signaling pathway. These results suggest that the decreased laminin of RGC-5 cells might be responsible for apoptosis induced by elevated hydrostatic pressure, and laminin or activating β1-integrin/FAK/AKT pathway might be potential treatments to prevent RGC loss in glaucomatous optic neuropathy.

Background Early detection of high-risk population for osteoporosis is the key to preventing this disease. Methodology: In this cross-sectional study a continuous sample of 270 women and 89 men (age: 20–90 years) was divided into four groups by age (≤ 55 or > 55 years) and sex. Participants completed the IOF test. Low-, medium-, and high-risk grades were defined by an OSTA index of greater than -1, -1 to -4, and less than -4, respectively. Results: Most participants were categorized in the low-risk group (240 people, 66.9%), followed by the medium-risk (102 people, 28.4%) and high-risk groups (17 people, 4.7%). Compared to women, men in both age groups had significantly higher OSTA index and greater numbers of positive answers on the IOF test. 64.3% individuals were susceptible to osteoporosis risk (≥1 positive answers on the IOF test). Multiple regression analysis demonstrated that family history of fragility fracture (OR: 0.503, 95% CI: 0.26–0.97), height loss exceeding 3 cm (OR: 2.51, 95% CI: 1.55–4.05), and earlier menopause (OR: 0.434, 95% CI: 0.19–0.97) were associated with higher risk grades. Conclusions: Combined use of the OSTA and IOF test is a simple and effective method for assessing the risk of osteoporosis.

ISO/IEC/IEEE 21451-5 standard provide a wireless communication model to facilitate access of smart sensors and actuators to a network. However, the 21451-5 standard integrates different wireless communication protocols in a sensor network system, and the overall complexity is higher than traditional sensor networks. Moreover, 21451-5 sensor networks that used in industrial control systems require better bit-error rate performance, and error correction is one of the key issues for the sensor networks. To address these obstacles, the double binary convolutional turbo code is applied to the 21451-5 sensor and actuator networks, and a low-complexity decoding solution is proposed for the iterative decoding, in which the focus is concentrated on simplification of the multivariable max * operator. In the implementation of a multivariable max * operator, this research shows recursion of the Jacobian logarithm is not necessary, and the computational error is small. Furthermore, we propose to approximate the Jacobian logarithm with simple compare, shifting, and addition operations. Since errors introduced by recursion of the Jacobian logarithm are removed, decoding performance of the proposed solution is superior to that of the near optimal decoding algorithm, and only slightly reduced as compared with the Log-MAP algorithm. By hardware implementation analysis, decoding complexity related to the multivariable max * operator is substantially reduced.

The objective of this study was to develop a remediation strategy for soil co-contaminated with decabromodiphenyl ether (BDE-209) and heavy metals (Cd, Pb and Zn) using co-plantation of the hyperaccumulator plant (Sedum alfredii) with tall fescue (Festuca arundinaceae) associated with a BDE degrader (Bacillus cereus strain JP12). A 120-day remediation experiment was conducted under greenhouse conditions. S. alfredii and tall fescue were grown in monoculture and intercropped in artificially contaminated soil. Plant biomass, concentration of polybrominated diphenyl ethers, density of soil bacteria, soil enzyme activity, and the physiological profile of the soil microbial community were determined. Inoculation with JP12 significantly increased BDE-209 dissipation in soil. Phytoextraction of metals was also enhanced by JP12 inoculation due to the improved plant growth. Planting of tall fescue significantly enhanced BDE-209 dissipation as compared to that in the bare soil because of the increased soil microbial activity. Tall fescue showed higher Pb phytoextraction efficiency than S. alfredii, but Pb was principally retained in the roots of tall fescue. BDE-209 dissipation and metal phytoextraction were highest when co-planting S. alfredii with tall fescue inoculated with strain JP12. Pyrosequencing analysis revealed that the inoculated JP12 could functionally adapt to the introduced soil, against competition with indigenous microorganisms in soil. Co-planting of S. alfredii with tall fescue combined with BDE-degrading bacterial strain JP12 is promising for remediation of soil co-contaminated with BDE-209 and metals.

The concept and connotation of the non-pneumatic tires were defined based on safety problems caused by punched and bursted tire. The types of the non-pneumatic tires were classified and the representative products were introduced and the developing trends were predicted. The necessity and feasibility of developing non-pneumatic tires with safety, versatility and efficiency were put forward and discussed.

Using chitosan-modified diatomaceous earth (DE) to treat micro-polluted water by coagulation/flocculation/sedimentation (C/F/S), the results indicated that the modified DE could apparently increase the removal rates of turbidity and UV254 in comparison with adding DE alone, and the optimal ratio between chitosan and DE was 1:40. With the compounding of polyaluminium chloride (PAC) and modified DE, the treatment effect was obviously improved by coagulation aid of modified DE under adding the same PAC dosage. The best removal rates of turbidity and UV254 reached 96.2% and 47.9% respectively with the PAC dosage of 35 mg/L and the modified DE dosage of 45 mg/L. The results indicated that the treatment effect of micro-polluted water improved with the enhanced coagulation of chitosan-modified DE.

In this study, Pseudomonas aeruginosa N2 was used to investigate the effects of biodegradation on paraffin crude oil for microbial enhanced oil recovery. Hydrocarbon degradation and the polar component production were illustrated by different analysis methods, respectively. Strain N2 had a high emulsion capability to enhance the dissolution of crude oil, which improved the utilization of crude oil. GC-MS results showed that the relative abundance of heavy hydrocarbon was decreased after biodegradation with the increase of hydrocarbon fractions of C19, C20and C25. ESI FT ICR-MS was used to study the changes of the polar components. Analysis revealed that the relative abundance of N1and O1species was decreased, corresponding to the increase of the relative abundance of N1O1, N1O2, N1O3and O2species. These polar components have the effort to reduce the interface tension and oil viscosity, thereby promoting anti-coalescence and reducing plugging to enhanced oil recovery.

Municipal biomass waste is regarded as new available energy source, although it could cause serious environmental pollution. Generally, biogas recovery by anaerobic digestion was seen as an ideal way to treat biomass waste. Different types of biomass waste have different biogas production potential. In this paper, cow manure, pig manure, municipal sewage sludge, fruit/vegetable waste, and food waste were chosen as typical municipal biomass waste. In addition, hydrothermal pretreatment was used to accelerate digestion and increase biogas production. Biochemical methane potential (BMP) test was used to evaluate biogas production for raw biomass and hydrothermal treated waste. Raw materials of fruit/vegetable and food waste show higher methane production than that of cow manure, pig manure, and municipal sewage sludge. After hydrothermal pretreatment at typical condition (170 °C at 1 h), the biogas production of pig manure, cow manure, fruit/vegetable waste, and municipal sewage sludge increased by 7.8, 13.3, 18.5, and 67.8% respectively. While, for treated food waste, the biogas decrease by 3.4%. The methane yield of pig manure, fruit/vegetable waste, and municipal sewage sludge increased by 14.6, 16.1, and 65.8%, respectively. While, for treated cow manure and food waste, the methane decrease by 6.9% and 7.5%.

Hybrid biofilm reactor has become a technically as well as economically feasible option for treatment of industrial wastewater. This article presents a critical review of some basic mathematical biofilm models. Mainly focus on the development and the solution of these models. The aim is to find a reasonable and simple model of hybrid biofilm reactor under aerobic and anoxic conditions and to simulate the decontamination of petrochemical wastewater.

Biogas generated from sewage sludge, livestock waste, and food waste by anaerobic digestion is a valuable renewable energy resource. However, conventional anaerobic digestion is not an efficient process. A long hydraulic retention time and low biogas recovery rate hinder the applications of those resources. An effective pretreatment method to destroy sludge microbial cells has been one of the major concerns regarding improvement of the biogas production. This article focuses on the effects of microwave heating on sludge anaerobic digestion. Volatile suspended solid (VSS) and chemical organic demand solubilization of heated sludge were investigated. Microwave heating was found to be a rapid and efficient process for releasing organic substrates from sludge. The increase of organic dissolution ratio was not obvious when holding time was over 5 min with microwave heating. The effect of the VSS solubilization was primarily dependent on heating temperature. The highest value of VSS dissolving ratio, 36.4%, was obtained at 170°C for 30 min. The COD dissolving ratio was about 25% at 170°C. Total organic carbon of treated sludge liquor was 1.98 and 2.73 g/L at 150°C and 170°C for 5 min, respectively. A biochemical methane potential (BMP) test of excess sludge and a mixture of primary and excess sludge demonstrated an increase in biogas production. The total biogas from microwave treated mixture sludge increased by 12.9% to 20.2% over control after 30 days of digestion. Biogas production was 11.1% to 25.9% higher for excess sludge than for untreated sludge. The VS removal ratios of mixture sludge and excess sludge were 12% and 11% higher, respectively, compared to the untreated sludge.

The community diversities of two oil reservoirs with low permeability of 1.81 × 10−3 and 2.29 × 10−3 μm2 in Changqing, China, were investigated using a high throughput sequencing technique to analyze the influence of biostimulation with a nutrient activator on the bacterial communities. These two blocks differed significantly in salinity (average 17,500 vs 40,900 mg/L). A core simulation test was used to evaluate the effectiveness of indigenous microbial-enhanced oil recovery (MEOR). The results indicated that in the two high salinity oil reservoirs, one reservoir having relatively lower salinity level and a narrow salinity range had higher bacterial and phylogenetic diversity. The addition of the nutrient activator increased the diversity of the bacterial community structure and the diversity differences between the two blocks. The results of the core simulation test showed that the bacterial community in the reservoir with a salinity level of 17,500 mg/L did not show significant higher MEOR efficiency compared with the reservoir with 40,900 mg/L i.e. MEOR efficiency of 8.12% vs 6.56% (test p = 0.291 > 0.05). Therefore, salinity levels affected the bacterial diversities in the two low permeability oil blocks remarkably. But the influence of salinity for the MEOR recovery was slightly.

In this paper, we propose an alternative model for collaboration networks based on nonlinear preferential attachment. Depending on a single free parameter "preferential exponent", this model interpolates between networks with a scale-free and an exponential degree distribution. The degree distribution in the present networks can be roughly classified into four patterns, all of which are observed in empirical data. And this model exhibits small-world effect, which means the corresponding networks are of very short average distance and highly large clustering coefficient. More interesting, we find a peak distribution of act-size from empirical data which has not been emphasized before. Our model can produce the peak act-size distribution naturally that agrees with the empirical data well.

By using the characteristic properties of the anti-Hermitian generalized anti-Hamiltonian matrices, we prove some necessary and sufficient conditions of the solvability for algebra inverse eigenvalue problem of anti-Hermitian generalized anti-Hamiltonian matrices, and obtain a general expression of the solution to this problem. By using the properties of the orthogonal projection matrix, we also obtain the expression of the solution to optimal approximate problem of an n×n complex matrix under spectral restriction.

By means of the properties of Hermitian-generalized Hamiltonian matrices, we give some necessary and sufficient conditions for the solvability of the matrix equation AX = B in Hermitian-generalized Hamiltonian matrix set $HHC^{n\times n}$. In the case where AX = B is solvable in $HHC^{n\times n}$, we derive the general representation of the solutions. We also give the expression of the solution for the corresponding optimal approximation problem.

We investigate convergence property of the restricted Broyden class of variable metric methods. We show that when these methods with unit step are applied to a strictly convex quadratic objective function, the generated iterative sequence converges to the unique solution of the problem globally and superlinearly. Moreover, the distance between the iterative matrix and the Hessian matrix of the objective function decreases with iterations. The sequence of function values also exhibits descent property when the iteration is sufficiently large.

The differences of temperature and formation water characteristics among each reservoir were significant in Dagang oilfield. Although many measures have been taken in an attempt to control steel pipeline corrosion, the corrosion rate in the south block of oilfield was several times higher than that of the middle and north blocks. Further studies, therefore, were needed to clarify the case. The ion and microorganism concentrations of the water in nine central stations were analyzed by sampling of aberration-free point. Under nonsterile and aseptic conditions, the relations among corrosion rate, salinity and SRB numbers were studied by static and dynamic methods. The results showed that, the salinity of formation water in the south block was the high (35g/L), and its SO42- content ranged from 50 to 150mg/L. In the south block of oilfield, the SRB number was less than 102cell/ml, but the corrosion rate was 71 percent higher than standard value. The case in the middle and north block of oilfield was inverse: the corrosion rate was 73 percent higher than that of the aseptic condition; production water was fit for microbial growth; the change law of pH and Eh was different. In the south block of oilfield, electrochemical corrosion was the main factor due to the higher salinity. In addition, microbiologically influenced corrosion was significant. The electron microscope analysis showed that, corrosion products were mainly iron and sulfur compounds, and calcium carbonate. The influence of SRB on corrosion was obtained by experiment between SRB numbers and corrosion rates. A preliminary strategy was proposed to control and reduce SRB numbers, as well as to reduce corrosion.

The effects of growing tall fescue on the biodegradation of hydrocarbons was studied in laboratory scale pots. Degradation of hydrocarbons as well as microbial counts, soil fluorescein diacetate activity, catalase activity and dehydrogenase activity were determined. The results showed that, in the rhizosphere soil system, total petroleum hydrocarbons disappeared faster than that in unvegetated pots soil. After 10 weeks, 11.8% and 27.4% of spiked petroleum hydrocarbons disappeared from the bulk and rhizosphere soils respectively. Abiotic loss of petroleum hydrocarbons by evaporation was of minor significance in the test. The microbial plate counts and soil enzyme activities were significantly higher in the rhizosphere than in the bulk soil. Petroleum compounds had significant effect on fluorescein diacetate hydrolyzing activity. Vegetation resulted in significantly greater first-order decay constants compared to the unvegetated control. Oxygenated polycyclic aromatic hydrocarbons that were present in the soil were generally degraded more slowly than the parent compounds, suggesting that they were formed during the treatment or that they are more persistent. Four oxidation products of polycyclic aromatic hydrocarbons, 1-acenaphthenone, 9-fluorenone, anthraquinone, and benzfluorenone were found at significantly higher concentrations at the end of the study.

NaOH was added into sludge to improve thermal hydrolysis when heated with microwave irradiation. Volatile suspended solid (VSS) rapidly dissolved into aqueous phase when adding 0.1 g NaOH per gram into suspended solid (SS) of sludge. More than 60% of VSS solubilized at 170 degrees C, and VSS to SS ratio of treated sludge reduced to 25%. For 5 min treatment, soluble COD (SCOD) in treated sludge liquid phase was 9.8, 12.8, 15.1, and 14.5 g/L respectively at 80, 120, 150 and 170 degrees C. Accordingly, the SCOD to TCOD (total COD) ratio was 24.0%, 31.3%, 36.9% and 35.6%. The pH of the microwave heated sludge decreased with higher temperature and longer hydrolysis time, while the finale pH of different testes were still higher than 10.5. Alkali dose effect on organic matters dissolving was analyzed at the range of 0-0.2 g NaOH into per gram SS. Results showed that when alkali dose was above 0.05 g, the rapid dissolving trend became level for VSS and SS. BMP (biochemical methane potential) test was used to investigate treated sludge digestibility at NaOH dose of 0.05 g with 5 min microwave heating at set temperature and 0.1 g with 1 min heating. Results showed that adding 0.05 g NaOH improved sludge anaerobic digestion, the biogas production was 28.5% higher than control at 150 degrees 2, while adding 0.1 g NaOH would inhibit treated sludge digestion process.