Search

To explore the effect and safety of transforaminal percutaneous endoscopic decompression for lower thoracic spinal stenosis.We reviewed 6 patients receiving transforaminal percutaneous endoscopic thoracic decompression for sympathetic symptoms in the lower extremities. Pre- and postoperative Frankel grade and Japanese Orthopaedic Association scale (JOA) score, Oswestry Disability Index (ODI) score, and visual analog scale (VAS) scores of back and lower extremities were also evaluated and recorded. Wilcoxon signed-rank test was performed for statistical analysis.All 6 patients completed the follow-up. Mean follow-up was 12.6 months. Frankel grade in all patients improved to normal at the third month after operation. JOA scores significantly increased from 4.4 (range, 3.5-5.0) preoperatively to 5.5 (range, 5.0-6.5) postoperatively, to 6.5 (range, 6.0-7.0) at 3 months, to 6.6 (range, 6.2-7.0) at 6 months, and to 6.6 (range, 6.2-7.1) at 12 months (P0.05). ODI scores significantly decreased from 71.2 (range, 65-78) preoperatively to 50.2 (range, 45-60) postoperatively, to 30.3 (range, 25-40) at 3 months, to 12.2 (range, 0-20) at 6 months, and to 10.2 (range, 0-15) at 12 months (P0.05). VAS back scores decreased from 7.8 (range, 7.0-9.0) preoperatively to 6.9 (range, 6.0-7.5) postoperatively, to 3.3 (range, 3.0-4.0) at 3 months, to 2.3 (range, 2.0-3.0) at 6 months, and to 1.9 (range, 1.5-3.0) at 12 months (P0.05). VAS lower extremity scores decreased from 8.7 (range, 8.0-9.0) preoperatively to 3.0 (range, 2.5-3.6) postoperatively, to 1.1 (range, 0.5-1.3) at 3 months, to 0.9 (range, 0.2-1.2) at 6 months, and to 0.3 (range, 0.1-1.0) at 12 months (P0.05). Four patients reported excellent results and 2 reported good results at the last follow-up.Percutaneous endoscopic transforaminal thoracic decompression is effective and safe in settling lower thoracic spinal stenosis.

Mining is considered to be one of the most significant sources of environmental pollution with regard to heavy metals. Mineral mining causes large quantities of mercury, cadmium, and other elements to be released into the environment and naturally poses a serious threat to environment. This paper will analyze the pollution status of agricultural soil caused by the mining of heavy metals in various mining areas in the Xunyang County in the Shaanxi Province of China, an area in famous for its resource mining. Equally, it will look at the potential ecological risk assessment process that is used to analyze the ecological risks of mining heavy metals in agricultural soil located in the surrounding areas. Based on the soil investigation, As pose a moderate ecological risk on the Au mining area. In addition, the Hg metals pose a significantly high potential ecological risk and Cd metals pose a considerable potential ecological risk on the Hg mining area. In the Pb-Zn mining area, a significantly high potential ecological risk was mainly posed by Cd. These results suggest that many heavy metals pose a high potential ecological risk on the agricultural soil in these three mining areas in the Xunyang County, and may cause elevated heavy metal contents in crops, eventually jeopardizing the health of local residents who consume food grown in polluted soil.

The land pollution in China is becoming more and more serious. Soil pollution has brought damages to farmers' economic and health benefits. Therefore, it is particularly important to make use of technical methods to turn contaminated land into available land. At present, soil pollution can be remediated gradually by physical, chemical and biological remediation. In this paper, the remediation methods for contaminated land is discussed and summarized. The repaired principles, research progress and application scope of various methods are reviewed. Finally, the development trend of contaminated land restoration industry is proposed in China.

It is well-known that both clay and organic matter in soils play a key role in mercury biogeochemistry, while their combined effect is less studied. In this study, kaolinite, vermiculite, and montmorillonite were coated or not with humus, and spiked with inorganic mercury (IHg) or methylmercury (MeHg). The potential bioavailability of mercury to plants or deposit-feeders was assessed by CaCl2 or bovine serum albumin (BSA) extraction. For uncoated clay, IHg or MeHg extraction was generally lower in montmorillonite, due to its greater number of functional groups. Humus coating increased partitioning of IHg (0.5%-13.7%) and MeHg (0.8%-52.9%) in clay, because clay-sorbed humus provided more strong binding sites for mercury. Furthermore, humus coating led to a decrease in IHg (3.0%-59.8% for CaCl2 and 2.1%-5.0% for BSA) and MeHg (8.9%-74.6% for CaCl2 and 0.5%-8.2% for BSA) extraction, due to strong binding between mercury and clay-sorbed humus. Among various humus-coated clay particles, mercury extraction by CaCl2 (mainly through cation exchange) was lowest in humus-coated vermiculite, explained by the strong binding between humus and vermiculite. The inhibitory effect of humus on mercury bioavailability was also evidenced by the negative relationship between mercury extraction by CaCl2 and mercury in the organo-complexed fraction. In contrast, extraction of mercury by BSA (principally through complexation) was lowest in humus-coated montmorillonite. This was because BSA itself could be extensively sorbed onto montmorillonite. Results suggested that humus-coated clay could substantially decrease the potential bioavailability of mercury in soils, which should be considered when assessing risk in mercury-contaminated soils.

The parameters of water contents, oxidation-reduction potential, organic matter, total phosphorus, total nitrogen and heavy metals concentrations of mercury (Hg), cadmium (Cd), lead (Pb), arsenic (As), chromium (Cr), copper (Cu) and zinc (Zn) in surface sediment and their vertical distribution incore sediments of the Heer river were investigated. Evaluation of nutrients and heavy metals in the Heer River sediments was done by pollution index and potential ecological risk index (PERI) method, respectively. Environmental dredging depth was calculated. The parameters pH, water content, total nitrogen (TN), and organic matter (OM) as well as heavy metals decline with the increased depth. Nutrients of TN, total phosphorus (TP), OM, and heavy metals Cd, Cu, and Pb were classified into the same group and there were significant positive correlations according to the principal component analysis and Pearson correlation, implying that they have a common origin. The results of high pollution index value of OM, TP, and TN of surface sediment obtained from this research showed that the Heer River was in serious nutrient pollution. The contributions of individual metals to the potential ecological risk were in the following order: Cd > Cu > Ni > Cr > Zn > As > Pb. Cd presented serious ecological risk and contributed most to the sediments of the Heer River. The ecological risk (RI) was at a considerable high risk level, and therefore, the environmental dredging depth of the Heer River is 94 cm for the purpose of reducing heavy metal contamination of the Heer River.

For the FAAS determination of water heavy metal elements to confirm the method to determine whether the laboratory had the ability to detect the method. According to General Requirements for the Competence of Testing and Calibration Laboratories, GB/T 27025-2008" in the relevant requirements of personnel qualifications, facilities, environmental conditions and equipment. The results had shown that the standard curve of each element was R = 0.999 or more, and detection limits, accuracy, precision results were in line with standard requirements. The results confirmed that the laboratory had the ability to develop this method.

The sediment of Shenzhen Mazhou River was collected and sieved with different particle sizes to determine the physicochemical properties, nutrient contents and heavy metal contents of sediment, interstitial water and oversize mud. At the same time, the single factor evaluation and potential ecological risk assessment of heavy metals were carried out on the sediment of Mazhou River. The experimental results show that the screening of different particle size has little influence on the physicochemical properties and nutrient content of sediment. Mazhou River nitrogen and phosphorus nutrients pose little ecological risk effect on the environment. The ecological risk ranking of heavy metals is Hg> Cd> Cu> Ni> As> Zn = Cr> Pb. Mazhou river sediment comprehensive potential risk index RI values are greater than 1200, indicating that Maozhou river was in extremely high risk. Among them, Hg contributes the most, which is the most important factor controlling the risk of heavy metal pollution in sediment.