Machine learning-based identification of segment joint failure in underground tunnels.

Shield tunnels that reside deep within soft soil are subject to longitudinal differential settlement and structural deformation during long-term operation. Longitudinal deformation can be classified into two modes: bending and dislocation deformation. The failure of bolts and engineering treatment techniques differ between these two modes. Therefore, it is imperative to accurately identify the tunnel's longitudinal deformation mode to determine the validity of the segment joint and implement appropriate engineering treatment. Traditional methods for detecting dislocation or opening suffer from high labour costs. To address this issue, this study presents an innovative identification method using a back-propagation neural network (BPNN) to detect segment joint failure in underground tunnels. First, this study collects the tunnel settlement curves of various subways located in the East China soft soil area, and it calculates tunnel settlement-dislocation and settlement-opening datasets using the equivalent axial stiffness model. A corresponding BPNN regression model is subsequently established, and the new settlement curve is the input to this regression model to predict the dislocation and opening, thereby determining the validity of the segment joint. The efficiency of this method is demonstrated through its successful application to the Hangzhou Metro Tunnel. This article is part of the theme issue 'Artificial intelligence in failure analysis of transportation infrastructure and materials'.

[Role of TGF-ß/Smad signaling pathway in diabetic kidney disease and research progress of traditional Chinese medicine intervention].

Diabetic kidney disease is an important microvascular complication of diabetes and the leading cause of end-stage renal disease. Its pathological characteristics mainly include epithelial mesenchymal transition(EMT) in glomerulus, podocyte apoptosis and autophagy, and damage of glomerular filtration barrier. Transforming growth factor-ß(TGF-ß)/Smad signaling pathway is specifically regulated by a variety of mechanisms, and is a classic pathway involved in physiological activities such as apoptosis, proliferation and differentiation. At present, many studies have found that TGF-ß/Smad signaling pathway plays a key role in the pathogenesis of diabetic kidney disease. Traditional Chinese medicine has significant advantages in the treatment of diabetic kidney disease for its multi-component, multi-target and multi-pathway characteristics, and some traditional Chinese medicine extracts, traditional Chinese medicines and traditional Chinese medicine compound prescription improve the renal injury of diabetic kidney disease by regulating TGF-ß/Smad signaling pathway. This study clarified the mechanism of TGF-ß/Smad signaling pathway in diabetic kidney disease by expounding the relationship between the key targets of the pathway and diabetic kidney disease, and summarized the research progress of traditional Chinese medicine in the treatment of diabetic kidney disease by interfering with TGF-ß/Smad signaling pathway in recent years, to provide reference for drug research and clinical treatment of diabetic kidney disease in the future.

Leaching of cadmium, chromium, copper, lead, and zinc from two slag dumps with different environmental exposure periods under dynamic acidic condition.

Over the past few decades, zinc smelting activities in Guizhou, China have produced numerous slag dumps, which are often dispersed on roadsides and hill slopes throughout the region. During periods of acid rain, these exposed slags release heavy metals into surface water bodies. A column leaching study was designed to test the potential release of the heavy metals cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) under simulated acid rain events. Two slags with varying environmental exposure periods were packed in columns and subjected to leaching solutions of pH 3.5, 5.5, or DI H2O at intervals of 1, 7, 14, 28, 56d. Pulse concentrations of Cd in leachate were found above 5µg/L, Cr, Pb, and Zn >10µg/L, whereas, Cu reached 10µg/L. After five leaching events, the leachability (percentage of cumulative heavy metal leached after five leaching events as in its respective total concentration in slags) of Cd was 0.05 percent and 0.035 percent from the old and young slag, respectively. Cr (0.035 percent and 0.05 percent) was greater than Cu (0.002 percent and 0.005 percent) and Zn (0.006 percent and 0.003 percent), while the lowest leachability was observed for Pb (0.0005 percent and 0.0002 percent) from the old and young slags, respectively. Reaction rates (release amount of heavy metals in certain period of leaching) of heavy metals in the leachates demonstrated the sequence of Zn>Cr>Cd, Cu>Pb. Leaching release of heavy metals was jointly affected by the pH of leaching solution and mineral composition of slags (including chemical forms of Cd, Cr, Cu, Pb, and Zn). Environmental exposure period of slags, resulting in the alteration of minerals, could affect the release process of heavy metals in leaching as well.

Hedysarum polysaccharide alleviates oxidative stress to protect against diabetic peripheral neuropathy via modulation of the keap1/Nrf2 signaling pathway.

Diabetic peripheral neuropathy (DPN) is a chronic complication of diabetes mellitus. Oxidative stress is implicated in DPN progression, suggesting that antioxidant therapy could be a viable anti-DPN method. Hedysarum polysaccharide (HPS) is an active component of Radix Hedysari, a plant that has been widely used as food and a herb for treating multiple diseases. Here, we evaluated the mechanisms of action of anti-DPN effects of HPS in genetically obese (ob/ob) mice. Schwann cells (SCs) were exposed to glucose (100 mM) in vitro and then treated with HPS at concentrations of 30, 60, 120, and 240 mg/L. Notably, HPS significantly inhibited high glucose-mediated cytotoxicity and oxidative stress by reducing malondialdehyde (MDA) levels and upregulating the expression of antioxidant enzymes (γ-glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione reductase (GR)) in SCs. Moreover, HPS increased the expression of nerve growth factor, stimulated Nrf2 signaling, and decreased Keap1 expression levels. Analysis of DPN mice models gavaged with HPS at 50, 100, and 200 mg/kg/d or lipoic acid (LA) at 30 mg/kg/d (positive control) for 8 weeks revealed that HPS markedly increased motor nerve conduction velocity (MNCV), shortened thermal withdrawal latency (TWL), and inhibited oxidative stress in serum and sciatic nerves of DPN mice models. Mechanistically, HPS suppressed Keap1 signaling and enhanced Nrf2 signaling in sciatic nerves. These findings imply that HPS ameliorates DPN via antioxidant mechanisms and by activating Keap1/Nrf2 signaling, suggesting that HPS is a potential treatment option for DPN.

Lead, zinc, and cadmium in vegetable/crops in a zinc smelting region and its potential human toxicity.

Lead, Zn, and Cd in vegetables/crops were investigated in a zinc smelting region in China, and their daily dietary intake by local residents was estimated. It is observed that Pb, Zn, and Cd were in 34.7-91.1, 242-575, and 0.199-2.23 µg g(-1) dry weight in vegetables/crops with their greatest concentrations in leafy vegetable. The daily dietary intake of Pb, Zn, and Cd by adult residents reached 3, 646, 59,295, and 186 µg day, respectively, and lettuce and cabbage together contributed 75% of the Pb, 50% of the Zn, and 70% of the Cd.

[Effect of Tangzhiping granule on blood lipids and free fatty acids in rats with insulin resistant diabetes].

OBJECTIVE: To investigate the effects of Tangzhiping Granule (TZPG) on blood lipids and free fatty acids (FFA) in rats with insulin resistant diabetes (IRD). METHODS: A blank control group consisted of randomly selected normal rats was set up. The remaining rats were established to IRD model by high-fat high-sugar diet feeding and streptozotocin injection. Then the 32 successfully modeled rats were randomized into the model group (treated by saline), the Tangmaikang group (treated with Tangmaikang Granule 1.35 g/kg), and the two TZPG groups treated with high dose (2.70 g/kg) and low dose TZPG (1.35 g/kg) respectively through intragastric infusion for 4 weeks. The body weight (BW), fasting blood glucose (FBG), insulin (INS), blood lipids including triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and FFA were detected, and the insulin sensitivity index (ISI) calculated. RESULTS: Compared with the blank control group, BW, FBG and INS increased while ISI decreased in the model group (P < 0.05 or P < 0.01). All the above-mentioned abnormal indices were improved in the three treated groups (Tangmaikang, high and low dose TZPG group), but the improvements in the high dose TZPG group were more significant than those in the other two groups (P < 0.05 or P < 0.01). Similar outcomes were also seen in blood lipids detection, in which TG, TC, LDL-C and FFA were higher and HDL-C were lower in model rats than those in blank controls, they were improved in the three treated groups (P < 0.05), and the best improvements were seen in the high dose TZPG group (P < 0.05). CONCLUSION: TZPG could reduce levels of BW, FBG, INS, TC, TG, LDL-C and FFA, and increase levels of ISI and HDL-C in rat model of insulin resistant type 2 diabetes, so as to improve the insulin resistance in them.

Acidic leaching of potentially toxic metals cadmium, cobalt, chromium, copper, nickel, lead, and zinc from two Zn smelting slag materials incubated in an acidic soil.

A column leaching study, coupled with acid deposition simulation, was conducted to investigate the leaching of potentially toxic metals (PTM) from zinc smelting slag materials (SSM) after being incubated in an acid Alfisol for 120 days at room temperature. Two SSMs (SSM-A: acidic, 10 yrs exposure with moderate high PTM concentrations versus SSM-B: alkaline, 2 yrs exposure with extremely high PTM concentrations), were used for the incubation at 0.5, 1, 2.5, 5 wt% amendment ratios in triplicate. Five leaching events were conducted at day 1, 3, 7, 14, and 28, and the leaching of PTMs mainly occurred in the first three leaching events, with the highest PTM concentrations in leachate measured from 5 wt% SSM amendments. After leaching, 2.5, 12, 5.5, 14, 11, and 9 wt% of M3 extractable Pb, Zn, Cd, Co, Cr, and Ni could be released from 5 wt% SSM-A amended soils, being respectively 25, 12, 4, 2, 2, and 2 times more than those from 5 wt% SSM-B amended soils. In the leachates, the concentrations of PTMs were mostly affected by leachant pH and were closely correlated to the concentrations of Fe, Al, Ca, Mg and P with Cd, Pb, and Zn showing the most environmental concern. Visual MINTEQ 3.1 modeling suggested metallic ions and sulfate forms as the common chemical species of PTMs in the leachates; whereas, organic bound species showed importance for Cd, Pb, Cu, and Ni, and CdCl+ was observed for Cd. Aluminum hydroxy, phosphate, and sulfate minerals prevailed as the saturated minerals, followed by chloropyromorphite (Pb5(PO4)3Cl) and plumbogummite (PbAl3(PO4)2(OH)5·H2O) in the leachates. This study suggested that incubation of SSMs in acidic soil for a long term can enhance the release of PTMs as the forms of metallic ions and sulfate when subjected to acid deposition leaching.

Environmental contamination of heavy metals from zinc smelting areas in Hezhang County, western Guizhou, China.

Total heavy metal (Cd, Cr, Cu, Pb and Zn) concentrations were evaluated in smelting waste, soil, crop and moss samples collected from the Hezhang artisanal zinc smelting areas, Guizhou, China. Soil samples from the cornfield near the smelting sites contained extremely high Cd (5.8-74 mg kg(-1)), Pb (60-14,000 mg kg(-1)) and Zn (260-16,000 mg kg(-1)) concentrations. Elevated heavy metal concentrations were also found in corn plants and total Pb (0.80-1.5 mg kg(-1)) and Cd (0.05-0.76 mg kg(-1)) concentrations in corn grain have totally or partially exceeded the national guidance limits for foodstuff. Thus, the soil-to-crop transfer of heavy metals might pose a potential health risk to the local residents. Similar to the high heavy metal levels in soil and corn, Cd, Cr, Cu, Pb and Zn concentrations in moss samples collected from the smelting sites ranged from 10 to 110, 10 to 55, 26 to 51, 400 to 1200 and 330 to 1100 mg kg(-1), respectively, exhibiting a local spatial pattern of metals deposition from the atmosphere. Based on examination of Zn/Cd and Pb/Cd ratios of the analyzed samples, we have distinguished between the flue gas dust derived and smelting waste derived metals in different environmental compartments.

The role of radix hedysari polysaccharide on the human umbilical vein endothelial cells (HUVECs) induced by high glucose.

BACKGROUND: Diabetes mellitus can cause a wide variety of vascular complications and it is one of the major risk factors for cardiovascular diseases (CVD). High glucose can induce vascular endothelial cell apoptosis. In this study, we investigated the effect of radix hedysari polysaccharide (HPS) on the depression of apoptosis of human umbilical vein endothelial cells (HUVECs) induced by high glucose. METHODS: HUVECs were treated with media containing 30 mM glucose in the presence or absence of vitamin C or HPS. The level of intracellular reactive oxygen species (ROS) and apoptosis of HUVECs was measured with flow cytometry. Expression of c-Jun NH(2)-terminal kinase (JNK) and caspase-3 were testified by real-time quantitative RT-PCR and immunofluorescence. RESULTS: High glucose was capable of eliciting the overexpression of JNK during the treatment procedure. Moreover, we found that the caspase-3 became overexpressed in apoptosis induced by high glucose; HPS could inhibit apoptosis under high glucose and suppress the generation of ROS and the overexpression of JNK and caspase-3. The effect of HPS on ROS quenching, inhibition of JNK and caspase-3 overexpression at the concentration of 100 µg/ml was similar to that of vitamin C at the concentration of 100 µM. CONCLUSION: The findings of the present study may suggest that HPS play a protection role on HUVECs against apoptosis induced by high glucose.