A Wind Bell Inspired Triboelectric Nanogenerator for Extremely Low­Speed and Omnidirectional Wind Energy Harvesting.

As one of the most promising renewable energies, wind energy is abundant in the natural environment. However, it is still challenging to effectively collect wind energy because of its variable wind speed and unpredictable direction. Here, a triboelectric nanogenerator, which is inspired by ancient Chinese wind bells, has been developed to collect energy from variable-speed and multi-directional wind. The wind-bell-inspired triboelectric nanogenerator (W-TENG) has the capability to generate electricity even at a very low wind speed of 0.5 m s-1. Furthermore, it is able to harvest wind energy effectively from all directions (0-360 degrees). The parameter-optimized W-TENG achieves a maximum output voltage of 9.3 V and a maximum current of 0.63 µA. Electronic devices including a digital watch and 40 light-emitting diodes (LEDs) are successfully powered by the designed W-TENG, demonstrating its applicability. In this study, it is believed that a novel and effective strategy is provided to harvest energy from variable-speed and multi-directional wind.

Application of ultrasound-guided percutaneous nephrostomy in the treatment of a solitary kidney with hydronephrosis due to renal tuberculosis.

PURPOSE: To investigate the value of ultrasound-guided percutaneous nephrostomy and nephrostomy tube replacement for treating a solitary kidney with hydronephrosis due to renal tuberculosis. METHODS: Clinical data of patients with a solitary kidney with hydronephrosis caused by renal tuberculosis who underwent ultrasound-guided percutaneous nephrostomy in our hospital from January 2011 to December 2022 were retrospectively analyzed. The associated success rate and complications were statistically analyzed, pre- and post-catheterization changes in serum creatinine and blood urea nitrogen levels were compared, success rate and complications of nephrostomy tube replacement in patients with long-term catheterization were statistically analyzed, and the impact of long-term catheterization on patient life was investigated. RESULTS: Overall, 32 patients aged 17-75 years (average age: 44.1 ± 16.9 years) underwent ultrasound-guided percutaneous nephrostomy. Sixty-three punctures were performed; the puncture success rate was 100%. The levels of serum creatinine and blood urea nitrogen of patients decreased after catheterization, and the differences between the pre-catheterization and post-catheterization were significant (P < 0.05). There were 1, 3, and 12 cases of serious, minor, and fistula-related complications, respectively. The mean duration of the indwelling catheter was 56.7 ± 36.2 (range, 13-120) months. The number of nephrostomy tube replacements was 344 times, and the success rate was 100%. All patients could take care of the puncture point by themselves. CONCLUSION: Ultrasound-guided percutaneous nephrostomy and nephrostomy tube replacement have a high success rate and few complications, which can improve the renal function of patients. It is of great value for treating a solitary kidney with hydronephrosis caused by renal tuberculosis.

Identification of critical effect factors for prediction of spatial and intra-annual variability of shallow groundwater nitrate in agricultural areas.

Shallow groundwater nitrate nitrogen (NO3--N) concentrations in agricultural areas usually show high spatial and intra-annual variability. It is hard to predict such concentrations due to the complexity of influencing factors (e.g., different forms of N in soil, vadose zone characteristics, and groundwater physiochemical conditions). Here, a large number of groundwater and soil samples were collected monthly over two years at 14 sites to analyze the soil and groundwater physiochemical properties and the stable isotopes of δ15N and δ18O of groundwater NO3--N in agricultural areas. Based on field observations, a random forest (RF) model was used to predict the groundwater NO3--N concentrations and reveal the importance of effect factors. The results show that there are large spatiotemporal variations in NO3--N, δ15N-NO3-, and δ18O-NO3- in groundwater. NO3--N is the major dominant specie of inorganic N in groundwater, and the groundwater NO3--N concentration in 24 % of the samples failed to meet the drinking water standard of the WHO (10 mg L-1). The RF model satisfactorily predicted groundwater NO3--N concentrations with R2 of 0.90-0.94, RMSE of 4.54-5.07, and MAE of 2.17-3.38. Groundwater nitrite and ammonium are the most important factors related to NO3--N consumption and production, respectively, in groundwater. Denitrification and nitrification were further identified by the relationships among δ15N-NO3-, δ18O-NO3-, and NO3--N, and by the ranges of δ15N-NO3-, δ18O-NO3-, temperature, pH, DO, and ORP in groundwater. Soil-soluble organic nitrogen (S-SON) and the depth of groundwater table were identified as vital factors related to N sourcing and leaching. Overall, as a first approach to adopting a RF model for high spatiotemporal-resolution prediction of groundwater NO3--N variations, the findings of this study enable a better understanding of groundwater N pollution in agricultural areas. Optimizing management of irrigation and N inputs is anticipated to reduce S-SON accumulation and mitigate the threat to groundwater quality in agricultural areas.

Contrast-enhanced sonography of juxtapleural pulmonary tuberculoma.

OBJECTIVES: The purpose of this study was to describe the findings of juxtapleural pulmonary tuberculoma on contrast-enhanced sonography and investigate their correlation with histologic findings. METHODS: From April 2008 to April 2012, 21 patients with biopsy or clinically proven juxtapleural pulmonary tuberculomas underwent contrast-enhanced sonography with an intravenous bolus injection of 4.8 mL of a sulfur hexafluoride-filled microbubble contrast agent. Enhancement patterns and functional parameters (time to enhancement, time to peak enhancement, and peak signal intensity) derived from a time-intensity curve were evaluated. Enhancement patterns were correlated with their histologic findings. RESULTS: A rim enhancement pattern was presented in 12 (57.1%), a homogeneous enhancement pattern in 5 (23.8%), and a heterogeneous enhancement pattern in 4 (19.1%) of 21 tuberculomas. A pathologic study confirmed that the nonenhancing center of the rim enhancement pattern corresponded to caseous or liquefied necrosis, and homogeneously enhanced portions corresponded to granulomatous inflammation. The medians (25th-75th interquartile ranges) for the time to enhancement, time to peak enhancement, and peak signal intensity were 14 seconds (9-14 seconds), 22 seconds (21-26 seconds), and 83 dB (55-92 dB), respectively. CONCLUSIONS: Contrast-enhanced sonography of juxtapleural pulmonary tuberculoma is feasible. Juxtapleural pulmonary tuberculomas usually show rim, homogeneous, or heterogeneous enhancement. Enhancement patterns of juxtapleural pulmonary tuberculomas are well correlated with their pathologic features.