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The settlement performance of an immersed tunnel in the Hong Kong–Zhuhai–Macau Bridge (HZMB) transportation project is described. The geological profile underlying the immersed tunnel is presented and the corresponding field monitoring system is introduced. The function of semi-rigid elements is analysed. The observed results related to longitudinal deformation patterns during construction (e.g. long-term settlement, differential settlement and structural behaviour) are described and analysed. Differential settlement occurred when there was a large variation in soil properties, at the joints of two adjacent elements and in different segments of the same element. Differential settlement occurred in both the longitudinal and transverse direction. During the operational period, permanent settlement was strongly related to back-silting. Tide loading and the immersion of adjacent elements may have caused transient settlement related to elastic deformation, but tide loading had less influence on the permanent settlement.

In this study, field monitoring testing and machine learning are used to analyze vegetated soil’s response to various rainfall events under natural environmental conditions. Parameters that reflect the soil, vegetation, and atmosphere of three monitoring points at different distances from a tree (0.5 m, 1.5 m, and 3.0 m) at a constant depth (0.2 m) are quantified and used for multivariate model development. A machine learning method, multi-gene genetic programming (MGGP), is used to formulate the relationships between two indices representing vegetated soil response and six selected influential parameters. Analysis indicates that for a complicated system, the MGGP method is suitable for establishing an efficient computational model under conditions of limited data. Global sensitivity analysis and parametric study are conducted, based on the obtained multivariate models, to reveal the effect of each influential parameter, indicating that rainfall pattern has much the same impact on variations in soil suction as rainfall amount and intensity and tree canopy do. An advanced rainfall pattern can trigger a more rapid response of vegetated soil than intermediate and delayed rainfall patterns can. Rainfall pattern’s effect on the descent rate of soil suction is nonlinear.

Columnar inclusion is a versatile and cost-effective technique for improving weak soils. Currently, most approaches are based on the “equal strain” assumption to calculate the deformation of soft ground reinforced by columnar inclusions. In this study, a new model to simulate the behavior of column-reinforced soft soil under equal stress conditions based on the variational principles is proposed. The proposed model satisfies the force equilibrium and deformation compatibility simultaneously, which is seldom fulfilled in traditional empirical methods or other analytical models. The corresponding analytical solution is obtained and its accuracy is verified by comparing it with the numerical solutions using finite element analysis. The comparisons of the proposed solution with an existing solution show that the proposed solution can provide very close agreement over a wide range of parameters while the existing solution is only able to provide a reasonable agreement for a certain range of stiffness ratio of the column and soft ground. In addition, a parametric study is made to illustrate the influence of various parameters on ground settlement predictions. The parametric study indicated that, by increasing the ratio of elastic modulus between the stone column and surrounding soils and the ratio between the radius of the stone column and the space of the stone column, the load transfer effect has been significantly improved, and the ground settlement becomes smaller. Furthermore, the Poisson’s ratio of the surrounding soil also has a very significant effect on ground settlement, while the effect of the Poisson’s ratio of the stone column on ground settlement is less significant compared with that of the surrounding soil.

This short communication reports a water inrush hazard during the construction of the Shijingshan Tunnel in Zhuhai, Guangdong, China. On 15 July 2021, a water inrush accident occurred at the construction site 1.16 km away from the tunnel entrance, resulting in 14 casualties. The purpose of this study is to investigate and discuss the water inrush process in this atypical case. The principal causes of this tunneling accident include the special geological conditions at the construction site, high hydraulic conductivity at the part that connects the underground water system and the overlying water body (the Jida Reservoir), and the impact of heavy rainfall. Moreover, four significant suggestions are proposed to prevent the possible occurrence of water inrush disaster: (1) assessing the risk level in areas prone to water inrush; (2) getting a comprehensive geological prediction based on borehole data and artificial intelligent methods; (3) establishing a monitoring system during the tunneling process; (4) strengthening the self-protection skills of construction workers.

A huge gas explosion occurred on 13 June 2021 in Shiyan City, China, resulting in 25 casualties and serious injuries to 37 people. The main victims of this explosion were stall keepers and customers buying breakfast and fresh vegetables in the food market. There is a continuous need to enhance the understanding of such unfortunate events, given the dangers they pose. This study analyzes the causes of this accident considering the general background and scenes of the explosion, and then describes the rescue operations undertaken. The investigation results revealed that the explosion was caused by the poor maintenance of gas facilities and negligence of safety regulations. It is, therefore, recommended that the control of these two main aspects be strengthened to reduce the recurrence of such unfortunate accidents.

In this study, a simplified axisymmetric model is built to simulate a column supported embankment system. The model is based on a cylindrical unit cell that contains one column with the surrounding soil and a layer of overlying embankment fill. The deformation of the column with the surrounding soil is simulated using a deformed shape function. The embankment fill is divided into an inner cylinder and an outer hollow cylinder to simulate the soil arching effect. The stress continuity and volume deformation continuity are applied to combine the behavior of the embankment fill and that of the column-reinforced foundation together. A semi-analytical solution is obtained, and it is verified using a finite element analysis and a case study. After that, parametric studies are put forward to evaluate the load transfer mechanism within the embankment fill, the shear stress at the interface between the column and the surrounding soil, and the vertical stress distribution within the column. The influences of the column modulus, the spacing between columns, the height of the embankment fill, and the length of the column on the soil arching effect are investigated and discussed. It is concluded that when the column modulus becomes larger, the stress ratio between the column and the surrounding soil increases correspondingly. The height of equal settlement plane is close to the net spacing between columns, but it changes slightly with a change in the column modulus.

Surcharge combined with vacuum preloading is a common technique for accelerating the consolidation process in ground improvement. A unit cell model for the axisymmetric consolidation of a soft soil using a prefabricated vertical drain (PVD) under a surcharge, combined with vacuum preloading, is investigated in this study. Based on this model, analytical solutions for a multi-layer soil system are put forward and the explicit expressions for two-layer and one-layer systems are presented. The accuracy of the proposed solution is verified using an analytical solution available in the literature. In the parametric study, the influencing factors on the consolidation process, such as, the smear zone, the PVD spacing, the hydraulic conductivity in the radial direction, the coefficient of vacuum decrease, are taken into account. The water flow in the radial direction plays an important role in the consolidation process while the impact of the vertical flow mainly develops around the interfaces between two adjacent layers. In addition, the proposed analytical solution is applied in a case history with three different layers and the results are reasonable.

In this chapter, the physical and chemical properties of natural fibers (i.e., natural moisture content, specific gravity, breaking tensile strength, breaking strain, cellulose, hemicellulose, lignin and ash) were examined for their influences in the soil reinforcement. A total of 11 factors including soil moisture content, soil density and fiber percentage were evaluated by using the Bayesian nonparametric general regression (BNGR) method. The robustness of the BNGR algorithm was validated using k-fold cross-validation. A parametric study was carried out to unveil the effects of these input variables. The results indicated that a higher fiber percentage or larger soil density induces higher reinforcement effect. Besides, the cellulose in a natural fiber is found to have a significant effect on the unconfined compressive strength (UCS) followed by the ash. With respect to the physical properties, the breaking strain is found to be highly correlated with the UCS, while the effects of fiber natural moisture content, specific gravity and breaking tensile strength are less significant parameters.

In this study, a new dual beam model was proposed for a geosynthetic-reinforced granular fill with an upper pavement. This dual beam model was subjected to a uniform surcharge loading and resting on an elastic foundation which was simulated by a Pasternak model. The upper pavement was modeled by an Euler–Bernoulli beam while the geosynthetic reinforced granular fill was simulated by a reinforced Timoshenko beam. The explicit derivation process for the behavior of this dual beam-foundation system was presented and an exact solution was obtained. A two-dimensional finite element analysis and a Pasternak model for simulating the granular fill were carried out to validate the reliability of the proposed dual beam model. A parametric analysis was put forward to investigate the behavior of this dual beam-foundation system. It was found that the length of the pavement structure and vertical uniform loading, the stiffness and shear modulus of the foundation soil had significant influences on the behavior of the dual beam-foundation system.

© 2019 Elsevier Ltd Soil arching effect results from the non-uniform stiffness in a geosynthetic-reinforced and column-supported embankment system. However, most theoretical models ignore the impact of modulus difference on the calculation of load transfer. In this study, a generalized mathematical model is presented to investigate the soil arching effect, with consideration given to the modulus ratio between columns and the surrounding soil. For simplification, a cylindrical unit cell is drawn to study the deformation compatibility among embankment fills, geosynthetics, columns, and subsoils. A deformed shape function is introduced to describe the relationship between the column and the adjacent soil. The measured data gained from a full-scale test are applied to demonstrate the application of this model. In the parametric study, certain influencing factors, such as column spacing, column length, embankment height, modulus ratio, and tensile strength of geosynthetic reinforcement, are analyzed to investigate the performance of the embankment system. This demonstrates that the inclusion of a geosynthetic reinforcement or enlargement of the modulus ratio can increase the load transfer efficiency. When enhancing the embankment height or applying an additional loading, the height of the load transfer platform tends to be reduced. However, a relatively long column has little impact on the load transfer platform.

In this study, analytical solutions are presented for the axisymmetrical consolidation of an unsaturated soil stratum on the basis of Fredlund and Hasan’s one-dimensional consolidation theo...

pyrotechnic mixtures are sensitivity with the influence of humidity and are susceptible to explosive decompositions. The aim of this paper is to provide thermal decomposition data under different humidity conditions. The method of TG-DSC simultaneous analysis has been used to study the thermal decomposition mechanism of a typical red pyrotechnic mixture. The kinetic parameters were calculated by kissinger method. The thermal stability is evaluated by decomposition peak temperature (Tm), mass loss (△m) and activation energy (E), which shows that the decomposition peak temperature and activation energy decreased obviously. Therefore, the thermal safety under humidity atmosphere become lower.

This study assesses the one-dimensional (1D) consolidation of unsaturated soil subjected to time-dependent loading based on the 1D consolidation theories of unsaturated soil. The differential quadrature method (DQM) is used to produce a general solution that considers various boundary conditions, various initial pore-water and pore-air distributions, and complex time-dependent loading. A special case in which the analytical solution is available in the literature is used for verification and accuracy analysis. It is found that the DQM solution can deliver more accurate results compared with the finite-difference method with a small number of sampling points. The general solution can avoid cumbersome computations in solving eigenequations encountered with the analytical solution. In addition, the proposed solution is more suitable for practical engineering because of its generality in complex initial, boundary, and loading conditions. Finally, the characteristics of the 1D consolidation of unsatura...

SUMMARY This paper presents a simple analytical solution to Fredlund and Hasan's one-dimensional (1-D) consolidation theory for unsaturated soils. The coefficients of permeability and volume change for unsaturated soils are assumed to remain constant throughout the consolidation process. The mathematical expression of the present solution is much simpler compared with the previous available solutions in the literature. Two new variables are introduced to transform the two coupled governing equations of pore-water and pore-air pressures into an equivalent set of partial differential equations, which are easily solved with standard mathematical formulas. It is shown that the present analytical solution can be degenerated into that of Terzaghi consolidation for fully saturated condition. The analytical solutions to 1-D consolidation of an unsaturated soil subjected to instantaneous loading, ramp loading, and exponential loading, for different drainage conditions and initial pore pressure conditions, are summarized in tables for ease of use by practical engineers. In the case studies, the analytical results show good agreement with the available analytical solution in the literature. The consolidation behaviors of unsaturated soils are investigated. The average degree of consolidation at different loading patterns and drainage conditions is presented. The pore-water pressure isochrones for two different drainage conditions and three initial pore pressure distributions are presented and discussed. Copyright © 2013 John Wiley & Sons, Ltd.

OCTOBER: To explore the effects of the glucagon-like peptide 1 (GLP-1) liraglutide on the penile erectile function of rats with diabetic erectile dysfunction (DED) by observing the impact of liraglutide on the expression of eNOS in the corpus cavernosum of diabetic rats.We randomly divided 30 six-week-old male SD rats into a normal control (n = 10) and an experimental group (n = 20) , established models of diabetes mellitus (DM) in the experimental rats, and subdivided them into a DM (n = 8) and a GLP-1 group (n = 8) to receive intramuscular injection of normal saline and liraglutide at 5 mg per kg of the body weight per day, respectively. After 12 weeks of intervention, we obtained the levels of FPG, FINS, TG, TC, HDL-C, LDL-C, testosterone, and IL-6 and the indexes of Homa-IR and Homa-β, detected the expressions of Akt/p-Akt and eNOS/p-eNOS in the corpus cavernosum by Western blot, and compared the erectile function between different groups.The frequency and rate of penile erection were significantly lower in the DM group than in the GLP-1 and normal control groups (P0.05) and also lower in the GLP-1 group than in the normal controls (P0.05). Immunofluorescence staining showed the expression of eNOS mainly in the cytoplasm of the cavernosal vessels and sinusoidal endothelial cells, markedly lower in the DM and GLP-1 groups than in the normal rats (P0.05), but higher in the GLP-1 than in the DM group (P0.05). The level of eNOS/p-eNOS in the penile tissue was significantly decreased in the DM and GLP-1 groups in comparison with the normal controls (P0.01 or P0.05), while that of p-eNOS was markedly increased in the GLP-1 group as compared with the DM group (P0.05). No statistically significant differences were observed in the Akt level among the three groups of animals (P0.05). The expression of p-Akt was remarkably reduced in the DM and GLP-1 groups in comparison with the control rats (P0.01 or P0.05), but higher in the GLP-1 than in the DM group (P0.05).GLP-1 can protect the function of endothelial cells in the corpus cavernosum and improve the erectile function of DED rats by regulating the Akt/ eNOS signaling pathway, which indicates that GLP-1 could be an important option for the treatment and prevention of DED.

In this paper, a semi-analytical method for the analysis of pile-supported embankments is proposed. The mathematic model describes the cooperative behavior of pile, pile cap, foundation soil, and embankment fills. Based on Terzaghi’s 1D consolidation theory of saturated soil, the consolidation of foundation soil is calculated. The embankments with two different types of piles: floating piles and end-bearing piles are investigated and discussed. The results of axial force and skin friction distributions along the pile and the settlements of pile-supported embankments are presented. It is found that it takes a longer time for soil consolidation in the embankment with floating piles, compared with the case using end-bearing piles. The differential settlement between the pile and surrounding soil at the pile top is larger for the embankment with end-bearing piles, compared with the case of floating piles.

Endothelial dysfunction represents an early step in the development of atherosclerosis. The purpose of this study was to investigate the relationship between postprandial lipaemia and endothelial dysfunction in patients with overt hypothyroidism (oHT) and subclinical hypothyroidism (sHT). Female subjects with oHT and sHT, as well as female healthy subjects with euthyroid state were enrolled (10 cases in each group). The examination of flow-mediated dilation (FMD) was performed before and after an oral fat-loading by high resolution ultrasound. Endothelial dysfunction after an oral fat challenge was related to the extent of hypertriglyceridemia and free radicals. FMD decreased significantly at 4-h point in 3 groups, (p < 0.05) and then FMD in control and sHT restored to baseline at 8-h point, it was lower than baseline in sHT group at 6-h point (p = 0.042). However, FMD continued to decrease at 6-h point (p < 0.001), and then increased toward to baseline at 8-h point, which was still lower than baseline (p = 0.039) in oHT. Spearman's analysis showed a negative correlation between FMD and triglyceride, a negative correlation between FMD and thiobarbituric acid reactive substances (TBARS), and a positive correlation between triglyceride and TBARS levels during oral lipid-loading test in hypothyroid patients (p < 0.001) and controls (p < 0.05). In hypothyroid subjects including oHT and sHT, even in healthy individuals, FMD was impaired after an oral fat challenge. The endothelial dysfunction observed after an oral fat challenge was related to the extent of hypertriglyceridemia and oxygen-derived free radicals.

Pyrotechnical battery is successfully prepared, including an anode and cathode having pyrotechnic charges with an excess of fuel-anode and an excess of oxidation agent cathode (Zr, CuO and asbestos), the anode and cathode being separated by a separator formed from LiF, ZrO2 and fibrous sponge. Main performance indexes system of pyrotechnical battery is put forward and tested under the premise of appropriate mass and corresponding size, such as discharge voltage, discharge time, activation time, excitation time, internal resistance, combustion temperature and storage life. The results show that pyrotechnical battery of Zr/CuO system can basically meet application requirements. Activation time is usually about 0.2 s. Discharge voltage is about 1.96 V and the discharge time is up to 13.8 s or more. The internal resistance keeps a low fixed value (0.47Ω , for example). Combustion temperature of pyrotechnic composition can reach 1500.6 °C (the case temperature of battery is lower) to ensure that electrode and separator is adequately melted, consequently, the internal resistance is reduced, and achieving satisfactory discharge effect.

ObjectiveImpairment of flow-mediated endothelium-dependent arterial dilation (FMD) exists in patients with subclinical hypothyroidism (sHT). Several studies showed that exercise training can improve FMD in patients with type 1 and type 2 diabetes. Therefore, we hypothesized that exercise training can also improve FMD in subjects with sHT. The purpose of the study was to test this hypothesis.Research design and methodsWe selected 30 sedentary women with sHT and 27 sedentary healthy women with euthyroid. All individuals participated in an exercise training of 6 months. Before and after exercise training, high resolution ultrasound was used to measure FMD.ResultsAt baseline, FMD among subjects with sHT was 3.87%, which was significantly lower than that in controls (5.98%; P2 max (36.7%; PPr=−0.596), TG (r=−0.532), and CRP (r=−0.511; PConclusionRegular aerobic exercise improves FMD in sHT patients, and changes of lipids and inflammation during the exercise period may partially contribute to the improvement of endothelial function.

Osteoprotegerin is a recently identified inhibitor of bone resorption. Recent studies indicate that osteoprotegerin also acts as an important regulatory molecule in the vasculature. The purpose of this study was to investigate the relationship between plasma osteoprotegerin levels and endothelium-dependent arterial dilation in type 2 diabetic patients. The study subjects included 40 newly diagnosed type 2 diabetic patients and 46 healthy subjects. All patients were given insulin therapy for 6 months. Plasma osteoprotegerin concentration was measured in duplicate by a sandwich enzyme-linked immunosorbent assay method, and high-resolution ultrasound was used to measure brachial artery diameter at rest, after reactive hyperemia, and after sublingual glyceryltrinitrate. The plasma osteoprotegerin level in patients before treatment was 3.36 ± 0.32 ng/l, which was significantly higher than that in control subjects (2.38 ± 0.25 ng/l, P < 0.001). After 6 months of treatment, osteoprotegerin levels decreased markedly (2.83 ± 0.34 ng/l, P < 0.001). Flow-mediated endothelium-dependent arterial dilation in patients before treatment was 3.21 ± 0.52%, which was significantly lower than that in control subjects (4.46 ± 0.56%, P < 0.01), and it improved markedly after 6 months of treatment (4.03 ± 0.49%, P < 0.01). In multivariate analysis, osteoprotegerin was significantly associated with endothelium-dependent arterial dilation, fasting blood glucose (FBG), HbA1c (A1C), and ultrasensitive C-reactive protein (CRP) at baseline (P < 0.01). The absolute changes in osteoprotegerin showed significant correlation with changes in endothelium-dependent arterial dilation, FBG, A1C, and CRP in diabetic patients during the course of treatment (P < 0.01). This study shows that plasma osteoprotegerin levels are elevated in newly diagnosed diabetic patients and are significantly associated with endothelial function.

The geosynthetic reinforced embankment is composed of pavement, embankment fills, geosynthetic layer and foundation soil. Due to the non-uniform displacement of embankment fill under loading and existence of supporting structures such as piles, shear stress will occur in the foundation soil. In this paper, an analytical model is proposed for geosynthetic reinforced embankment. Embankment fill is modeled as a Timoshenko beam embedded with a geosynthetic layer, and the pavement is simulated by an Euler-Bernoulli beam. Two types of beam models are employed so that both bending moment and shear stress in the embankment are taken into consideration. Based on the theories of the Euler-Bernoulli beam and the Timoshenko beam, governing equations are proposed for geosynthetic reinforced embankment on an elastic foundation. The analytical solution has been derived using appropriate continuity and boundary conditions under strip loading. It can be observed that the length of the pavement structure and foundation soil stiffness have much influence on the displacement and bending moment distributions of the embankment system.

To observe the positive rates of autoantibodies against beta1 adrenergic receptors (beta1-receptor) and angiotensin II type 1 receptors (AT(1)-receptor) in type 2 diabetes patients with or without hypertension.The epitopes of the second extracellular loop of beta1-receptor (197 - 222) and AT(1) receptor (165 - 191) were synthesized and serum autoantibodies were determined in type 2 diabetes patients with hypertension (n = 171) or without hypertension (n = 106). Left ventricular dimension was determined by echocardiography. The 24-hour urinary protein was measured by ELISA. The risk factors for enlarged left ventricle were analyzed by multiple logistic regressions.The positive rates of the autoantibodies against beta1-receptors (45.0%) and AT(1)-receptor (46.2%) in patients with type 2 diabetes with hypertension were significantly higher than those in patients with type 2 diabetes without hypertension (16.0% and 10.4%, respectively, all P0.01). In type 2 diabetes patients with hypertension and enlarged left ventricle, the positive rates of the autoantibodies against beta1-receptor 61.4% (35/57) and against AT(1)-receptor 64.9% (37/57)were significantly higher than those in type 2 diabetes patients with normal left ventricular dimension (36.8%, 42/114 and 36.8%, 42/114, respectively, all P0.01). Regression analysis demonstrated that course of disease, systolic pressure, serum autoantibodies against beta1 adrenergic receptor and angiotensin II type 1 receptors sera autoantibodies were independent risk factors for left ventricular enlargement (all P0.05).The serum beta1 and AT(1)-receptor autoantibodies are related to enlarged left ventricle in type 2 diabetes patients with hypertension and suggest that autoantibodies against beta1 and AT(1)-receptor might play important roles in the pathogenesis of type 2 diabetes patients with hypertension and enlarged left ventricle.

To explore the relation between the positive rates of autoantibodies against beta(1) adrenergic receptor (beta1-receptor)and (M2-receptor) with urinary albumin excretion rate (UAER) in type 2 diabetes patients with refractory hypertension.Autoantibodies against beta(1)- and M(2)-receptor as well as autoantibodies were determined in type 2 diabetes patients with (n = 136) or without (n = 111) refractory hypertension, hypertensive patients without renal failure (n = 60) and healthy control subjects (n = 40, control) by ELISA.The positive rates of the autoantibodies against beta1-receptors (44.9%) and M(2)-receptor (37.5%) in patients with type 2 diabetes with refractory hypertension were significantly higher than those in patients with type 2 diabetes without refractory hypertension (27.9% and 24.3%, respectively, all P0.05), in patients with hypertension without renal failure (11.7% and 15.0%, all P0.01) and in healthy controls (8.3% and 7.5%, all P0.01). In type 2 diabetes patients with refractory hypertension and renal failure (UAERor = 200 microg/min), the positive rates of the autoantibodies against beta(1)-receptor (87.1%, 27/31) and against M(2)-receptor (67.7%, 21/31) were significantly higher than those in type 2 diabetes patients with refractory hypertension but without renal failure (UAER 20 - 199 microg /min, 46.7%, 28/60 and 41.7%, 25/60, respectively, all P0.05).The serum beta(1)- and M (2)-receptor autoantibodies are positively associated with the UAER level and suggest that these autoantibodies against beta(1) and M(2)-receptor may play important roles in the pathogenesis of the type 2 diabetes with refractory hypertension.

Impaired glucose tolerance (IGT) is considered a transitional phase in the development of type 2 diabetes, and is also independently associated with the occurrence of cardiovascular disease. Endothelial dysfunction (ED) represents a very early step in the development of atherosclerosis. The aim of the present study was to examine ED in the fasting state and after a glucose challenge as well as after administration of an antioxidant agent.The study subjects included 42 IGT patients and 26 healthy individuals (control group). The IGT patients were randomly divided into two groups, 21 in each group (the alpha-lipoic acid group and the placebo group). In the alpha-lipoic acid group, 300 mg of alpha-lipoic acid was administrated before an oral glucose tolerance test (OGTT); in the placebo group, 250 ml of 0.9% sodium chloride was administrated before the OGTT. In addition, 250 ml of 0.9% sodium chloride was also administrated to the control subjects before the OGTT (control group), and then vascular function was examined in the fasting state and repeated 1 and 2 h after the glucose load. High-resolution ultrasound was used to measure flow-mediated endothelium-dependent arterial dilation (FMD) and glyceryltrinitrate (GTN)-induced endothelium-independent arterial dilation.In the fasting state, and at 60 and 120 min, FMD in both the placebo and alpha-lipoic acid groups was significantly lower than in the controls (P0.01). In the control group, FMD tended to decrease at 60 min after glucose loading and returned to the baseline levels at 120 min (P0.05). In the placebo group, FMD decreased significantly at 60 min after glucose loading (P0.01) and increased markedly from 60 to 120 min (P0.01). The alpha-lipoic acid-treated patients showed FMD values intermediate between the control subjects and the IGT patients treated with placebo, at both 60 and 120 min, and the differences were significant (P0.01). In multiple regression analysis, FMD was significantly correlated to fasting blood glucose (FBG), low density lipoprotein cholesterol (LDL-C), lipoprotein (a) [Lp(a)], C-reactive protein (CRP), thiobarbituric acid reactive substances (TBARS) and age in IGT patients at baseline (P0.01). Spearman's analysis showed a significant negative correlation between FMD and plasma glucose levels, and between FMD and TBARS during the OGTT in IGT patients (placebo group) (P0.01). There was also a significant correlation between FMD and plasma glucose levels, and between FMD and TBARS during the OGTT in IGT patients treated with alpha-lipoic acid (P0.05), although the power of association decreased.In subjects with IGT, FMD was impaired both in the fasting state and after a glucose challenge, probably through increased production of oxygen-derived free radicals. The ED observed after a glucose challenge is related to the extent of hyperglycaemia and TBARS, and an antioxidant agent can improve the impairment of endothelial function induced by acute hyperglycaemia.

To investigate the alteration of plasma osteoprotegerin (OPG) concentration before and after levothyroxine (L-T4) replacement therapy and its association with endothelium-dependent arterial dilation in patients with overt hypothyroidism (oHT) and subclinical hypothyroidism (sHT).L-T4 therapy was given to 20 oHT patients and 20 sHT patients, all female, till the free serum triiodothyronine (FT3), free thyroxin (FT4), and thyroid-stimulating hormone (TSH) were near or within the respective normal ranges. Twenty healthy women were used as controls. Sandwich ELISA was used to measure the plasma OPG concentration before and after treatment.The plasma OPG levels before treatment of the oHT and sHT patients were 3.13 ng/L +/- 0.27 ng/L and 2.95 ng/L +/- 0.24 ng/L respectively, both significantly higher than that of the controls (2.42 ng/L +/- 0.26 ng/L, both P = 0.000). Multivariate analysis showed that OPG was significantly associated with TSH (r = 0.306, P0.05) and endothelium-dependent arterial dilation (r = -0.675, P0.01) at baseline. After the normalization of thyroid function the OPG levels of the oHT and sHT patients decreased markedly to 2.53 ng/L +/- 0.28 ng/L and 2.54 ng/L +/- 0.21 ng/L respectively (both P = 0.000), very close to that in the controls. The absolute changes of OPG was significantly positively correlated with the changes of TSH (P0.05), negatively correlated with the changes of endothelium-dependent arterial dilation (P0.01), and not significantly correlated with other parameters in the hypothyroid patients during the course of treatment.OPG may act as an important regulatory molecule in the vasculature and, particularly, may be involved in the development of vascular dysfunction in hypothyroid patients.

To investigate the relationship between the plasma osteoprotegerin (OPG) level and endothelium-dependent arterial dilation in type 1 diabetic patients.Sandwich ELISA method was used to detect the plasma OPG levels of 22 newly diagnosed type 1 diabetic patients before and 6 months after treatment and of 28 healthy subjects. All patients were then given insulin therapy for 6 months. High resolution ultrasound was used to measure the brachial artery diameter at rest, after reactive hyperemia and after sublingual administration of glyceryltrinitrate (GTN).The plasma OPG level of the patients before treatment was 3.09 ng/L +/- 0.70 ng/L, significantly higher than that of the healthy controls (2.07 ng/L +/- 0.75 ng/L, P0.001). After 6 months treatment, the OPG level of the patients decreased to 2.58 ng/L +/- 0.59 ng/L, significantly lower than that before treatment (P0.001). The flow-mediated endothelium-dependent arterial dilation in the patients before treatment was 3.35% +/- 0.67%, significantly lower than that of the healthy controls (5.17% +/- 0.83%, P0.001), and was increased to 4.27% +/- 0.63% after 6 months treatment, significantly higher than that before (P0.001). Multivariate analysis showed that OPG level was significantly associated with endothelium-dependent arterial dilation, fasting blood glucose (FBG), hemoglobin A1c (HbA1c), and ultra-sensitive C-reactive protein (CRP) at baseline (all P0.01). The absolute change in OPG level was significantly correlation with the changes in endothelium-dependent arterial dilation, FBG, HbA1c, and CRP in the diabetic patients during the course of treatment (all P0.01).Plasma OPG level is elevated in newly diagnosed diabetic patients, and the plasma OPG level is significantly associated with endothelial function.

Osteoprotegerin (OPG) regulates osteoclast and immune functions and appears to represent a protective factor for vascular system. However, the role of OPG in endothelial dysfunction of type 1 diabetic patients has not been evaluated. The purpose of this study was to investigate the relationship between plasma OPG levels and endothelium-dependent arterial dilation in type 1 diabetic patients.This study subjects included 22 newly diagnosed type 1 diabetic patients and 28 healthy subjects. All patients were then given insulin therapy for 6 months. Plasma OPG concentration was measured in duplicate by a sandwich ELISA method, and high-resolution ultrasound was used to measure brachial artery diameter at rest, after reactive hyperemia and after sublingual glyceryltrinitrate (GTN).Plasma OPG level in patients before treatment was 3.09+/-0.70 ng/L, which was significantly higher than that in control (2.07+/-0.75 ng/L) (p0.001). After 6 months treatment, OPG levels decreased markedly (2.58+/-0.59 ng/L) (p0.001). The flow-mediated endothelium-dependent arterial dilation in patients before treatment was 3.35+/-0.67%, which was significantly lower than that in control (5.17+/-0.83%) (p0.001), and improved markedly after 6 months treatment (4.27+/-0.63%) (p0.001). In multivariate analysis, OPG was significantly associated with endothelium-dependent arterial dilation, fasting blood glucose (FBG), hemoglobin A1c (HbA1c), and ultra sensitive C-reactive protein (CRP) at baseline (p0.01). The absolute changes in OPG showed significant correlation with the changes in endothelium-dependent arterial dilation, FBG, HbA1c, and CRP in diabetic patients during the course of treatment (p0.01).This study shows that plasma OPG levels are elevated in newly diagnosed type 1 diabetic patients, and that plasma OPG levels are significantly associated with endothelial function.

To explore the role of the autoantibodies against M(2)-muscarinic receptor (M(2)-receptor), beta(1)-adrenergic receptor (beta(1)-receptor) in the development of diabetic with refractory hypertension.Serum autoantibodies against M(2) and beta(1) were detected by ELISA using synthesized epitopes of the second extracellular loop of M(2) receptor (169 - 193) and beta(1) receptor (197 - 222) in healthy controls (n = 40), diabetic patients (n = 62), diabetic patients with non-refractory hypertension (n = 55) and diabetic patients with refractory hypertension (n = 81).The positive rates of the autoantibodies against M(2) receptor and beta(1) receptor were similar among healthy controls (15.0% and 17. 5%), diabetes mellitus patients (17.7% and 14.5%) and diabetic patients with non-refractory hypertension (16.4% and 12.7%) but are significantly higher in diabetic patients with refractory hypertension (64.2% and 55.6%, P0.01 vs. other 3 groups).This finding suggests that autoimmune mechanisms might play a role in the pathogenesis of diabetic patients with refractory hypertension.