Geogenic enrichment of potentially toxic metals in agricultural soils derived from black shale in northwest Zhejiang, China: Pathways to and risks from associated crops

Agricultural soils derived from black shale are typically enriched in potentially toxic metals. This is a serious problem, both in terms of the ecological environment and human health. To assess the levels of potentially toxic metals, 90 paired soil-crops samples were collected from the Anji Country, western Zhejiang province, a typical exposed black shale area in China. Concentrations and bioavailability of potentially toxic metals in the soil-crops system were measured, and the associated potential risks were further evaluated. Results showed the enrichment of potentially toxic metals (i.e. Cd, Pb, Cu, Zn and Ni) in the soil and crop samples, especially a significant accumulation of Cd. Sequential extraction data indicated that Cd in soils derived from black shale was the second most dominant element in the exchangeable fraction (mean at 33.42%) and possessed high bioavailability, whereas Pb was mostly retained in the residual fraction (mean at 76.34%) and exhibited low mobility. The total concentration as well as mobility and bioavailability of Cd were the highest in the sampled soils. This resulted in a high potential ecological risk in areas with agricultural soils derived from black shale, which could eventually jeopardize the health of local residents through various exposure pathways. Overall, our findings provide a scientific basis for developing suitable management strategies to mitigate the exposure to potentially toxic metals in high risk areas

A new method for preventing stress cracking in repairable ceramic packages by changing the sealing ring shape

High-reliable ceramic packages are impressionable to the parallel seam welding (PSW) parameters leading to low yield and reliability. In this study, the structure of the ceramic package was modified by changing the sealing ring to improve weldability and high-temperature reliability. Three types of ceramic packages with different-shaped sealing rings, which are conventional rectangular rings, notch inward rings, and notch outward rings, were fabricated by Au-Sn soldering and a follow-up PSW process. The packages with the rectangular ring failed in the subsequent high-temperature aging test. The packages with the notch inward ring exhibited an early failure after PSW. Cracks were generated in the Au-Sn solder and propagated into the ceramic substrate. The packages with the notch outward ring exhibited remarkable weldability and reliability. Sequential thermo-structural coupling was used to simulate the temperature and stress distribution in the packages. The maximum principal stress in the aforementioned ceramic substrates rapidly increased to approximately 170.0 MPa, 168.5 MPa and 101.4 MPa in the PSW process. Stress concentration existed at the outside corner around the rectangular and notch inward-shaped sealing rings. The maximum temperature at the local position in the ceramic was raised to 250.3 °C, 238.6 °C and 157.2 °C depending on the shape of the sealing ring. The extra transmission path in the notch outward ring relieved thermal mismatch and deformation at the Au-Sn/ceramic interface during PSW. The packages with notch outward rings were recommended especially in the repairable ceramic packaging

The effects of single and combined application of ramipril and losartan on renal structure and function in hypertensive rats

The objective of the present study was to investigate the effects of single and combined administration of ramipril and losartan on renal structure and function in spontaneously hypertensive rats (SHRs). Thirty-two 9-week-old SHRs and eight Wistar-Kyoto (WKY) rats were randomly divided into five groups: the WKY control group, the SHR control group, the SHR-ramipril group, the SHR-losartan group, and the SHR-combined mediation group. The rat body weight, SBP, heart rate, and urinary albumin excretion rate (UAER) were measured. (1) The SBP was reduced to the normal level in all groups of rats except for the SHR control group. Combined administration of ramipril and losartan can be reduced to the normal level earlier than single (P < 0.01). (2) The SHR-ramipril group and the SHR-losartan group still experienced a higher UAER than that in the WKY control group (P < 0.01). (3) The renal mass/BW ratio was decreased in the SHR-ramipril group, SHR-losartan group, and SHR-combined medication group compared to that in the SHR control group (P < 0.01). (4) Compared with the SHR control group, the SHR-ramipril group, the SHR-losartan group, and the SHR-combined medication group had a lower percentage of the IOD of glomerular collagen relative to the glomerular area (P < 0.01). (5) The reduction in tubulointerstitial injury score was more significant in the SHR-combined medication group than in the SHR-ramipril group and the SHR-losartan group (P < 0.01). The combination of ramipril and losartan is superior to either single drug in reducing the UAER, resisting glomerular collagen deposition, and protecting renal tubular structure

Identification and predictive control for a circulation fluidized bed boiler

Key Research Project of Fujian Province of China [2009H0044]; National Natural Science Foundation of China [61174161]; National Important Project [2010ZX04001-162]; Key Research Project of Xiamen City of China [3502Z20123014]; Fundamental Research Funds for the Central Universities in China (Xiamen University) [201212G005]; Fundamental Research Fund for the university student Creative and Entrepreneurship training program in China (Xiamen University) [XDDC201210384063]; National Science Foundation of China [60934007]; 973 Program of China [201203720500]This paper introduces the design and presents the research findings of the identification and control application for an industrial Circulation Fluidized Bed (CFB) boiler. Linear Parameter Varying (LPV) model is used in the model identification where steam flow is selected as the operation-point (scheduling) variable. Three kinds of weighting functions, namely linear, cubic splines and Gaussian functions are compared. LPV model based Model Predictive Control (MPC) is also simulated. Test results show that LPV model is more accurate than linear model, and LPV MPC yields a better control effect than linear MPC. (C) 2013 Elsevier B.V. All rights reserved

Cloning and Characterization of the Human Integrin β6 Gene Promoter

<div><p>The integrin β6 (ITGB6) gene, which encodes the limiting subunit of the integrin αvβ6 heterodimer, plays an important role in wound healing and carcinogenesis. The mechanism underlying ITGB6 regulation, including the identification of DNA elements and cognate transcription factors responsible for basic transcription of human ITGB6 gene, remains unknown. This report describes the cloning and characterization of the human ITGB6 promoter. Using 5′-RACE (rapid amplification of cDNA ends) analysis, the transcriptional initiation site was identified. Promoter deletion analysis identified and functionally validated a TATA box located in the region −24 to −18 base pairs upstream of the ITGB6 promoter. The regulatory elements for transcription of the ITGB6 gene were predominantly located −289 to −150 from the ITGB6 promoter and contained putative binding sites for transcription factors such as STAT3 and C/EBPα. Using chromatin immunoprecipitation assays, this study has demonstrated, for the first time, that transcription factors STAT3 and C/EBPα are involved in the positive regulation of ITGB6 transcription in oral squamous cell carcinoma cells. These findings have important implications for unraveling the mechanism of abnormal ITGB6 activation in tissue remodeling and tumorigenesis.</p></div

Luciferase reporter assay for the human ITGB6 gene promoter.

<p>(A&B) The ITGB6 promoter-luciferase constructs are schematized. All numbers presented are relative to the TSS of the human ITGB6 gene. Luciferase reporter constructs containing various lengths of the ITGB6 promoter, or the promoter-less plasmid pGL2-basic, were co-transfected with pRL-TK into TCA8113 cells and 293T cells. Luciferase activity was measured at 48 hr after transfection. The luciferase value of the pGL2-basic was set to a value of one. Relative promoter activities are presented on the right (mean ± SEM, at least three independent experiments) and are analyzed by one-way ANOVA, where * <i>p</i> < 0.05, ** <i>p</i> < 0.01, and ** <i>p</i> < 0.001. (C) Nucleotide sequence of the main promoter region of the ITGB6 gene, depicting predicted binding sites for the transcriptional factors (underlined).</p

Identification of the transcriptional start site of the human ITGB6 gene.

<p>(A) Gel analysis of 5′-RACE experiments on total RNA from oral squamous cell carcinoma cells. Lane 1: DL2000 Marker, Lane 2: a single amplicon detected by 2% agarose gel electrophoresis. (B) The portion of the human ITGB6 nucleotide sequence depicting the positions of the translation initiation site and transcription start site. (C) Sequencing result of 5′-RACE.</p